Pepper Spray Government Study

8/2/2019 Pepper Spray Government Study

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The author(s) shown below used Federal funds provided by the U.S.Department of Justice and prepared the following final report:

Document Title: Impact of Oleoresin Capsicum Spray on

Respiratory Function in Human Subjects in theSitting and Prone Maximal Restraint Positions,Final Report

Author(s): Theodore C. Chan M.D. ; Gary M. Vilke M.D. ;Jack Clausen M.D. ; Richard Clark M.D. ; PaulSchmidt M.S. ; Thomas Snowden ; Tom Neuman

M.D.

Document No.: 182433

Date Received: May 18, 2000

Award Number: 98-IJ-CX-0079


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FINAL REPORT - OCspray and Position

THE IMPACT OF OLEORESIN CAPSICUM SPRAY ONRESPIRATORY FUNCTION IN HUMA N SUBJECTS IN THESITTING AND PRON E MAXIMAL RESTRAINT POSITIONS

PROPERTY OFi.Jaiiona\Criminal Justice Reference Service (NCJRS)

FINAL REPORT

Theodore C. Chan, MD*Gary M. Vilke, MD*Jack Clausen, MD#Richard Clark, MD*+Paul S chmidt, MS"Thom as Snowden"Tom Neuman, MD*#


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FINAL REPORT - OC spray and Position

I.

11.

111.

IV .

TABLE OF CONTENTS

EXECUTIVE SUMMARY

PROJECT D ESCRIPTIONA. IntroductionB. Project Goals, Objectives and SignificanceC. Background

SCOPE AND METHODOLOGYA. Study Design and LocationB. Human SubjectsC. Experimental ProceduresD. Experimental ProtocolE. Data Collection and An alysis

DETAILED FINDINGSA. Study SubjectsB. Effect of OC Exposure in the Sitting PositionC. Effect of OC Exposure in th e Restraint PositionD. Effects of Other Factors


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FINAL REPORT - OC pray and Position

I. EXECUTIVE SUMMARY

Introduction. Oleoresin Cap sicum (OC) spray has gained w ide acceptance inlaw enforcement as a swift and effective force method to su bdue violent, dangeroussuspects in the field. Derived from the extract of the capsicum pepper plant, OC spraycauses inflammation and edem a over areas of co ntact (primarily the face, eyes, nose andmouth), resulting in pain a nd discom fort such that many victims lose their capacity toresist.

With w idespread use, however, OC spray has been alleged to have beenassociated with a number of in-custody deaths in the media. Becau se symptom s ofcough, gagging and shortness of breath are com mon with OC exposure, concern ha sfocused on the respiratory effects of OC spray as playing a potential role in these deaths.

Moreover, individuals subdued with OC spray in the field often require physicalrestraint, including the prone maximal restraint or hobble position. Som e have arguedOC in combination with restraint can lead to significant respiratory compromise an d riskfor asphyxiation and death.


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FINAL REPORT - OC pray andPositionThe goal of our study was to assess the safety of a comm ercially available OC

spray in use by law- enforcemen t agencies nationwide. Specifically, we examine d bothOC spray and positional restraint in human subjects to determine if OC exposure by itselfor in com bination with positional restraint resulted in any significant respiratorycomprom ise as measured by pulmonary function testing and assessment of oxygenationand ventilation.

Methodology. We c onducted a random ized, cross-over, controlled trial onvolunteer human subjects recruited from the local la w enforcement training academy .Prior to participation, data were collected on subject we ight, height, age, gende r, historyof lung disease, smoking, and medication use. Subjects performed 4 ifferentexperimental trials over 2 separate days in a pulmona ry function testing laboratory inrandom order:

a. Placebo spray exposure followed by sitting position;b. Placebo spray exposure followed by restraint position;c. OC spray exposure followed by sitting position;d. OC spray exposure followed by restraint position.


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Subje cts then placed the ir head in a 5 x 3 x 3 expos ure box that allow ed theirface to be exposed to OC or placebo spray (see EXHIBIT A). A one-second OC o rplacebo spray was delivered into the box from the end opposite the subject(approximately 5 feet away). Subjects remained in the box for 5 seconds after the spraywas delivered. During this time, subjects underwent im pedance monitoring to assesswhether inhalation of the OC or placebo spray occurred.

After this exposure period, subjects were placed i n either the sitting or pronemaximal restraint position (by means o f handcuffs and a restraining cuff currently in useby local law enforcement agencies). Subje cts remained in these positions for 10minutes.Repeat spirometric measurem ents (FVC and FEV 1) were performed at 1.5 and 10minutes. Oxygen saturatio n, end-tidal C 0 2 levels, and pulse rate were recorded at 1,5,and 9 minutes. Blood pressures were recorded at 3, 6, and 9 minutes. An arterial bloodsample was drawn at 8 minutes to assess arterial oxygen (p02), C 0 2 (pC 02 ), and acid-base status (PH levels).

After the 10 min ute period, the subject had a 1 hour rest and was hout period toallow for resolution of any residual effects from either exposure or position. After this


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FINAL REPORT - OC pray and Positionor placebo) and position (sitting and restraint) to dete rm ine if any significant differencesexisted between the 4 experimental trials. A probability value of less than 0.05 (afterBuonferroni correction for independent variables) was considered statistically significant.Clinical significance was determined by any evidence of abnormal pulmonary function(spirometric measurements below 80% of predicted), hypoxemia (oxygen saturation 45 mmH g). Dataanalysis was performed by m eans of a computerized statistical software package (Stata6.0 for W indows, Stata Corporation@).

Results. A total of 34 out of 37 subjects (24 m en and 10 women) completed thestudy, performing 136 trials (4 rials for each subject). Of the 3 subjects w ho did notcomplete the study, 2 were excluded due to acute injuries prior to the study that preventedstudy participation (one subject with an acute rib fracture, and another with an acuteforearm fracture). On e subject wa s excluded after he suffered a fainting episode duringblood draw phlebotomy . This subject recovered uneventfully. The incident occurredduring the subjects first trial, in which he wa s randomized to the sitting position afterplacebo exposure. He wa s never exposed to OC or restrained at any time.


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FINAL REPORT - OCspray and Positionpredicted F E V l: 100.1 vs. 100.3% at baseline, 98.9 vs. 98.9% at 1.5 minutes, and 99.2

vs. 99.0% at 10 minutes, respectively) (see E XH IBIT C and D).There was also no difference in oxygenation or evidence of hypoxem ia between

the placebo and OC groups in the sitting position (mean oxygen saturation: 99.2 vs.99.2% at baseline, 99.0 vs. 99.1% at 1 minute, 98.6 vs. 99.0% a t 5 minutes, and 99.5 vs.98.0% at 9 minutes; mean arterial p0 2 : 96.8 vs. 99.4 mm Hg at 8 minutes, respectively).OC exposure led to slightly lower C 0 2 levels when com pared with placebo, but noevidence of hypercapnia in either group (mea n end-tidal C 0 2 levels: 38.0 vs. 38.2 mmH gat baseline, 36.8 vs. 32.4 mmH g at 1 minute, 36.5 vs. 32.9 m mH g at 5 minutes, and 37.0vs. 35.2 mm Hg at 9 minutes; mean arterial pC 02 : 39.4 vs. 36.4 mmH g for placebo andOC groups, respectively) (see E XH IBIT E and F).

In the restraint position, FVC and F EV l significantly decreased with restraintposition, but remained w ithin clinical normal limits. Despite this decline there wa s nodifference found between pla cebo and OC groups (mean YO redicted FVC: 101.9 vs.103.4% at baseline, 87.5 vs. 87.5% at 1.5 minutes, and 87.9 vs. 87.2% at 10minutes;mean YO redicted F EV1: 99.7 vs. 101.1% at baseline, 83.2 vs. 82.5% at 1.5 minutes, and


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at baseline, 38.8 vs. 36.7 mmHg at 1 minute, 39.1 vs. 36.6 mmHg at 5 minutes, and 39.5vs. 37.7 mmHg at 9 minutes; mean arterial pC02: 40.9 vs. 39.1 mm Hg for placebo andOC groups, respectively) (see EX HIB IT E a nd F).

In both the sitting and restraint groups, OC exposure led to sma ll, but statisticallysignificant increases in blood pressure as determ ined by mea n arterial pressure (MAPequal to one-third of systolic pressure + two-thirds of diastolic pressure). Th is differencepersisted up to 9 minutes after exposu re (for sitting position: mean MAP 10 1 O vs. 103.4mm Hg at baseline, 103.8 vs. 116.8 mmH g at 3 minutes, 100.7 vs. 112.1 at 6 minutes, and98.1 vs. 107.8 mm Hg a t 9 minutes; for restraint position: 102.2 vs. 10 2.7 mm Hg atbaseline, 102.0 vs. 110.7 at 3 minutes, 99.1 vs. 108.2 mm Hg at 6 minutes, and 100.1 vs.110.0 mmHg at 9 minutes for the placebo and OC groups, respectively) (see EX HIBITHI.

Discussion. In this study, we found no evidence that OC spray inhalation andexpos ure in human subje cts resulted in any respiratory com prom ise, as measured bypulmonary function testing, oxyg en and C02 levels, in the sitting position. Moreove r,there was no evidence of hypoxem ia or hypercapnia as a result of OC exposure. In fact,


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FINAL REPORT - OCspray and Positionexposure and, similar to the results in the sitting position, OC seemed to increaseventilation as evidenced by small decreases in C 0 2 levels for this group.

Based o n these results, we conclude that OC exposure and inhalation do not resultin a significant risk for respiratory comprom ise or asphyxiation. Mo reover, even whencombined with positional restraint, OC inhalation does not result in an increased risk ofventilatory failure or asphyxia tion.

OC exposu re did, however, resu lt in an increase in blood pressure. Th e etiologyof this increase remains unclear, but may be in part due to the discomfort and painassociated with OC. Th e clinical ramificatio ns of this elevation in blood pressure remainunknown.

This study has a number of limitations. First, as this study was conducted in apulmonary function laboratory, not all condition s that occur in the field se tting where OCand restraint are employed, could be reproduced. Factors that commonly occur in thefield setting, such as physical strugg le, physiolo gic and psychological stre ss, agitation,drug intoxication, trauma and exertion, were not studied in our investigation. Seco nd,though we believe our protocol adequa tely replicated a single OC exposure in the field,


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FINAL REPORT - OCspray and PositionOC exposure places subjects at significant risk for respiratory compromise orasphyxiation.


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FINAL REPORT - OC spray and Position11. PROJECT D ESCR IPTION

A. INTRODUCTIONLaw en forcemen t personnel have a variety of force options when dealing with

dangerous, combative, and violent subjects in the field. O n a continuum of increasinglevels of force, these o ptions include officer presence, verbal dialogue, physical controland restraint, chem ical agents, impact weapo ns, and lethal force or weapon s. W hilehigher levels of force are likely to subdue and control subjects more swiftly, theyincreasingly place both subject and officer at greater risk for injury.

In this regard, the s uccess of O leoresin Capsicum (OC) or pepper spray, and itsability to tem porarily incapacitate subjects, has led to its adoption as a force option bylaw en forcement agencies nationwide. OC spray has been credited with decreasinginjuries among officers and sub jects by reducing the need for more dangero us forceoptions.

Despite its success, there is grow ing concern regarding the safety of OC spray,particularly when co mb ined with positional restraint. Ther e have been a number of in-


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FINAL REPORT - OC spray and Positionsensorium or excited delirium induced by d rug abuse. Subjects may ha ve underlyingcardiopulmonary disease or an obese body habitus. Violent physical struggle is oftenfollowed by physical restraint.

Attention has focused on these factors, and in particular the use of physicalrestraint, to explain these deaths. In fact, many of these deaths have been attributed topositional asphyxia, the theory that subjects placed in a prone maxim al restraint positionare at risk for fatal respiratory comprom ise from restricted chest and abdom inalmovement.

As opposed to other factors, OC spray use and positional restraint are directlyrelated to policing action, practices and policies. A s a result, these force options havereceived tremendou s focus, attention and scrutiny from th e public, media a nd lawenforcement comm unity. Moreover, it is jus t these types of controversial custody deathsthat become contentious public issues and strain relations between law enforcem entagencies and their commun ities.

Some have gone so far as to label both OC spray and positional restraint as form sof police brutality and excessive force. Litigation has arisen, impacting the financial


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FINAL REPORT - OCspray and Positionhuman subjects had ne ver been studied, and we re largely unknown, particularly withrespect to pulmonary and respiratory function.

B. STUDY GOALS, OBJECTIVES AND SIGNIFICANCEThe goal of this study was to assess the safety of OC spray by itself and in

combination with physical restraint. Specifically, we e xamined both OC spray andpositional restraint in human subjects to determine i f OC spray exposure by itself or incombination w ith positional restraint resulted in any significant comprom ise inrespiratory or pulmonary finction.

The specific main objectives of this study were:1. To determine if OC spray inhalation in the sitting position results in clinically

significant respiratory com prom ise as me asured by pulmonary func tion testingand assessment of oxygenation and ventilation;

2. To determine if OC spray followed by the prone maxim al restraint results inclinically significant respiratory com promise as measured by pulmonaryfunction testing and assessm ent of oxygenation and ventilation.


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FINAL REPORT - OC spray and Position4. Whether body size and weight influence the effects of OC spray in regards to

respiratory and p ulmonary function as m easured by pulm onary functiontesting and assessment of oxygenation an d ventilation.

5. Whether pu lmonary disease (such as asthma), the use o f respiratory inhalermedications, or history of sm oking tobacco influence the effects of OC sprayin regards to respiratory and pulmonary function as measured by pulmonaryfunction testing and assessment o f oxygen ation and ventilation.

This study represents a unique collaboration between regional law enforcementagencies and the local academic medical institution to assess and improve the safety ofpolicing practices in our comm unity. Specifically, this study wa s a joi nt effort of the SanDiego Regional Public Safety Training Institute, as part of the San Diego C ity Police andSan Diego Co unty Sh er if fs Departments, and the Department of Emergency M edicine(and its Division ofMedical T oxicolog y) and Department o f Internal Medicin e (and itsDivision of Pulmonary and Critical Care M edicine), at the University of Ca lifornia SanDiego Medical Center.


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History. Japanese sa mura i warriors used pepper extrac ts placed in rice paper bagsto throw at the eyes of enemies and cause temporary blindness. Chinese fighters wouldheat red pepp ers in hot oil to form an irritant sm oke while in battle. In 1973, oleoresincapsicum became available in aerosol spray formulations for use to incapacitate anim alsand hum ans on a temporary basis, and was initially used by FBI personnel and US m ailcarriers. During the late 1980s, OC spray was widely adopted by law enforcementagencies nationwide and also became available for general public use a s personneldeterrent devices. ,13,14

Currently, hand-held canister spray mod els are produced and used i n this country.These models produce an aerosol, liquid stream or foam spray, with O C concentrationsvarying from 1 to l o%, mixed in a carrier solvent such a s isopropyl alcohol, denaturedethanol, or propylene glycol. Actual amounts of capsaicinoids are ~a ri ab 1e .I ~nlikeother classic forms of tear gas and mace such as CN (2-chloro-acetophenone) and CS (0-chlorobenzyl-idenemalononitrile), epper sprays are felt to be more immediatelye ffe ctiv e, s afe r and l es s t o x i ~ . ~ , ' ~

OC Spray Effects. Biochem ically, capsacinoids stimulate chemon ociceptors in


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FINAL REPORT - OC spray and Positionlacrimation, involuntary blepharospasm, and rarely corneal abrasions. Because of theseimm ediate, severe ocular sympto ms, many subjects lose their capacity to resist.

On contact with skin, OC spray cause s severe burning sensation with localinflammation and e rythema. OC spray also causes a local inflammatory reaction in thenose and oral mucosa, resulting in rhinorrhea, swelling, and pain. With acute exposures,these effects are transient and reportedly last anyw here from 30 to 60 rninutes.l4

Respiratory Effects.With inhalation or exposure to the oropharynx, OC spraycauses a variety of imme diate respiratory symptoms, including cough, gagging, inabilityto vocalize and subjective shortness of breath. In acute exposures, these sym ptom s areusually limite d, lasting 15 to 30 minutes.I4

Reports of Fatalities. The number of custody deaths following OC spray haveparalleled the rise of its use nationwide and raised concern regarding its safety. In 1994,Granfield reported o n 30 custody deaths associated with expo sure to OC spray from 1990through 1993.' An additional 60 or more deaths have been reported since that time.5

Concern has focused on th e respiratory effects of OC spray as playing a potentialcausal role in these deaths. There have been reports of children who suffered significan t


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FINAL REPORT - OC sprqv and PositionStudies on Capsaicin. Evidence that OC may hav e significant respiratory effects

is based on research on inhaled nebulized capsaicin. Because of its ability to inducecough, capsaicin has been studied ex tensively as a mod el for understanding the coughreflex. There ha s also been interest in capsaicin because of its ability to block painsensation and pruritis, presumably by depletion of substance P an d otherneurotransmitters.

Wh ile animal and in-vitro hum an tissue studies suggest capsaicin inducessignificant increases in airway resistance and bronchoconstriction, I8*l9 clinical studieswith nebulized capsaicin are less clear. In 1985, Fuller reported that inhaled nebulizedcapsaicin resulted in a transient dose-dependent increase in airway resistance, m axim al at20 seconds and lasting less than 60 seconds. There was no difference between normalsubjects and those with a history of asthma or smoking.*' The lack of spirometricevidence for sustained bronchoconstriction w as further substantiated by Collier andBlanc, both of whom found no significant decrease in forced expiratory volum e in 1second (FEV 1) in human subjects who inhaled nebulized capsaicin at concentrationssufficient to induce


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Capsaicin has been found to stimulate both C and A delta sensory afferent fibersin the airway and pulmonary parenchyma in animal studies, and has been implicated inprecipitating a transient bronchoco nstriction and cou gh reflex. In addition, it has beensuggested that stimulation o f these nerve endin gs could precipitate a pulmonarychem oreflex, resulting in bradycardia, hypo tension, and apnea.16

Studies on OCSpray. Unlike capsaicin, research on the hum an effects of OCspray are limited.5 A two-year joint study by the FB I and US Army determined that nolong-term health risks were associated with OC spray.27 Other stud ies have been limitedto retrospective reviews of law enforcem ent experience in the field. Granfield et a1reviewed 30 cases of custody deaths that occurred after OC spray exposure. Twen ty-twoof these cases had enough information that cause of death could be determined. In nocase was death attributed to OC exposu re.' Since that time, another 60 deaths followingOC spray exposure have been reported, of wh ich o ne was attributed to asphyxiation frombronchospasm precipitated by OC spray.2,3,5,28

In reviewing OC spray use in 1996, the California State Attorney Generalreported that no fatal consequences occurred in over 23,000 exposures.29 W atson et a1


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Positional AsphyxiaIn their review , Granfield e t a1 reported that all victims were placed in physical

restraints during or follow ing OC spray exposure. Granfield suggests the majority ofdeaths can be attributed to positional asph yxia rather than OC spray exposure. In fact,law enforcement agenc ies have implemented po licies limiting certain physical restraintsand body positions after 0,C spray exposure.31,32,33

I

CaseReports. The term positional o r mechanical asphyxia has been used toexplain the d eaths of individuals who w ere found i n body positions that caused upperairway obstruction or interfered with ventilatory function.34 The term has also beenapplied to asphyxiation deaths where ch est restraints wrapped around the n ecks ofindividuals resulting in strangulation.restraints that allegedly com pressed the chest and abdom en to the point that mechanicalventi la tion was im ~a ir ed .~ * ~*

35,36 There have been reports of deaths caused by

More recently , the theory of positional asp hyxia has been used to explain thesudden custody deaths of individuals who were placed in the maximal prone o r hogtie


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FINAL REPORT - OCspray and Positionreported prolonged recovery times for transc utaneous oxygen saturation and heart rate insubjects placed in the restraint position as opposed to sitting after mild exercise."

However, Reay m ade no assessment of a ctual ventilatory function and respiratorymechanics in subjects placed in the restraint position. T ranscutaneous oximetry is anindirect measure of blood oxygenation and frequently inaccurate under conditions ofexercise.42943 lso, Reay reported oxygen desaturations down t o 85% with exercise,substantially lower than what would be expected at such relatively mild levels of exertionin healthy s ~ b j e c t s . 4 ~ ~ ~ ~

Previously, we conducted a more comprehensive study examining the physiologiceffects of this position.46 Fifteen healthy volun teers underwent a two-phase random ized,cross-over controlled trial that evaluate d stati c and dyn am ic respiratory function. First,subjects underwent pulmonary function testing (PFT ) in fo ur static positions: sitting,supine, prone, and restraint. We found a progressiv e restrictive pulmonary functionpattern as subjects went from sitting to supine and prone to restraint positions. Meanforced vital capacity (FV C) fell progressively (decline s of 7%, 7% an d 13% of predictedfor supine, prone and restraint positions respectively), as did m ean F EV l (declines of 8%,


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FINAL REPORT - OCspray andPosition

exercise regimen, we found no evidence of a delay i n heart rate recovery in subjects

placed in the restraint position afte r exercise.46Thus, while ou r initial findings with static positions suggested the possibility of

hypoventilation, our results in the dynam ic phase found no evidence to support the theoryof positional asphyxia. Moreover, as PFT measurements as lo w as 80% of predictedvalues are still normal, these static positional changes are of little clinical r e l e ~ a n c e .~ 'The fact that these changes were clinically insignificant is further emphasized by the factthat small changes in pulm onary function were found sim ply in the supine and pronepositions as well.

Schm idt et a1 also found no significant physiologic differences in their study o f 18subjects placed in the sitting and restraint positions after exercise. In addition, theystudied subjects after a simulated pursuit and physical struggle regimen and found nodifferences in oxygen ~a tu ra ti on .~ ' ogers et a1 studied 10healthy volunteers in both theprone and lateral restraint positions and found no differences in peak expiratory flowrates or oxygen saturation after exercise.49

Limitations. How ever, these studies exam ined positional restraint in healthy


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FINAL REPORT - OC pray and Positionspray. OC spray inhalation in comb ination with positional restraint has not been

previously studied to determine if the com bination of these force methods results in anydetriment in pulmonary function that places individuals at risk for respiratorycompromise and arrest.


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FINAL REPORT - OC sprqv and Position

111. SCOPE AND METHODOLOGY

A. Study Design and LocationWe conducted a random ized, cross-over, controlled trial to assess the effect of OC

spray exposure o n pulmonary and respiratory function in the sitting and prone maximalrestraint positions in volunteer human subjects.

Specifically, volunteers performed f our (4) ifferent experimental trials over tw oexperimental days in random order:

a. Placebo (no OC ) spray exposure followed by sitting position;b. Placebo spray exposure followed by restraint position;c. OC spray exposure followed by sitting position;d. OC spray exposu re followed by restraint position.Subjects performed two of the trials during each experimental day. The order of

the trials was randomized. However, to prevent two exposures to OC spray in a singleexperimental day, no subject was randomized to perform both trials c and d on the same


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FINAL REPORT - OC s p r v and PositionB. Human Subjects

Volunteers were recruited am ong training cad ets from the S an Diego RegionalPublic Safety Training Institute, which trains law enforcem ent personnel for the S anDiego City Police and San Diego County Sheriff's Departments. Recruitmen t wasconducted in conjunction with personnel staff at the Training Center (Mr. T. Snowdenand Mr. P. Schm idt). As a routine part o f their training, cadets are exposed to OC sprayon a voluntary basis in order to fu rther their understanding of the effects of the spraywhen used in the field.

Informed written consent was obtained f rom all subjects prior to participating inthe study. Potential subjects were told that participation in the study was completelyvoluntary and that participation would in no way affect their training or advancement.

No exclusion was m ade on the basis of race, ethnicity, age, obesity or history o fpulmonary disease such as asthma. Subjects completed a short questionnaire regardingtheir health status, history of lung disease and asthma, smok ing history, medication use,and respiratory inhaler medication use. Prior to experime ntation, subjects underwentbrief screening spirometry in the sitting position by means of a portable spirometry


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FINAL REPORT - OC prqv and PositionC. xperimental Procedures

Sitting and R estraint Body Po sitions. In the sitting position, the subject sat in achair with feet flat on the floor and back upright against the back of the chair. In therestraint position, the subject lay prone on th eir stomach on a medical exam ination tablewith head turned to the side. The subjects wrists were bound together behind the back

by means of police handcuffs. The subjects ankles were bound together and securednear the wrists by m eans of the maximal restraint cuff currently used by law enforcemen tagencies in San Diego Cou nty.

Placebo and OCSpray Exposure. OC and placebo spray exposure wasfacilitated by use o f a 5 foot by 3 foot by 3 foot plastic exposure box (see EXHIBIT A).On one end o f the expo sure box, a large ventilation hood w as attached. On the opp ositeend, a small opening was created from which OC or placebo spray was delivered.

The hoo dexp osure box was adapted for this study for a number of reasons. First,this method allowed for a m ore uniform and reproducible spray exposure andconcentration within the box. Second , this method allowed the spray to be deliveredfrom a standard d istance of 5 feet (the length of the box) and targeted at the subjects


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FINAL REPORT - OC pray and Positionenforcement agencies. Placebo spray was delivered by a similar canister containing only

the carrier and propellant agents (68%% isopropyl alcohol and 31.5% isobutane/propane.The canister wa s used to deliver a 1 second OC or placebo spray into one end of

the exposure box, approximately 5 feet from the subjects face. The subjects headremained in the hood of th e exposure bo x for 5 secon ds after the spray was released.

Pulmonaryfunction testing. Pulmonary function testing was performed in thestandard mann er of the UC SD Pu lmonary Function Laboratory. PFT measurements wereobtained in accordance with the Am erican Thoracic Societys criteria, includingreproducibility within 5% on three repeat mea~urernents.~~pirometric measurementscollected included forced vital capacity (FVC) and forced expiratory volume in 1 second(FEV1) obtained using a Medgraphics Cardiopulmonary Diagnostic Sy stem @ machine.

Cardiopulmonary M onitoring. Subjects cardiopulmonary status was monitoredcontinuously throughout the experimental trials in the following manner.

1. Electrocardiographic (ECG) monitoring by 3-lead continuous monitor usinga Quinton Instrument 40008;

2. Serial blood pressure monitoring by automated sphygmomanometer located


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FINAL REPORT - OC pray and Position4. Expired gases and end-tidal C 0 2 monitoring by means of a quantitative C 0 2

detector using a Med graphics Cardiopulm onary Exercise System cP x/ D @machine.

Arterial Blood Gas. Arterial blood g as (AB G) collection and analysis occurred inthe following manner. UCS D PF T laboratory technicians collected 1-2 cc of arterialblood from either radial artery at the subjects wrist under sterile conditions in thestandard technique with an ABG arterial puncture kit. ABG analysis was performed inthe ABG laboratory of UCSD Medical Center in the standard fashion to determine pH,p0 2, pC 02 , and oxygen saturation by co-oximetry. All measurements were made induplicate on two different AB G analyses.

Impendance Monitoring. Transthoracic impedance monitoring using an EdentecSleep Recorder System@ was performed on subjects during the 5 second spray exposureperiod to assess whether inhalation occurred during the exposure period.

D. EXPERIMENTAL PROTOCOL


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FINAL REPORT - OC spray and Positionsubject then placed his or her head in the hood portion of the exposure box. The subject

was allowed to wea r safety eye goggles at his or he r discretion.OC or placebo spray was delivered into the box fro m a distance of 5 feet from th e

subjects face as described above. The subject remained in the hood of the exposure boxfor 5 seconds after the spray, during whic h time, im ped anc e monitoring wa s used toassess that the subject inhaled.

After the 5 second exposure period, the subject w as rem oved from th e exposurebox and imm ediately placed into the sitting o r restraint position (as described above )depending on the particular experimental trial. The subject remained in this position for10 minutes.

During this time, continuous cardiopulmonary monitoring was performed asoutlined above. Data were collected and recorded i n the following manner:transcutaneous oxygen saturation recorded at 1 , 5 , and 9 minutes; heart rate recorded at 1,5 , and 9 minutes; expired ga s end-tidal C 0 2 levels recorded at 1, 5, and 9 minutes; andarterial blood pressure measured at 3 , 6 , and 9 minutes.

At 1.5 minutes into the period, spirometric pulmonary function testing was


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FINAL REPORT - OC spray and Positionthe subject was removed by mean s of wash ing with soap and water as recomm ended by

the manufacturer.Once the trial was completed, all monitoring devices were remove d and the

subject rested for 1 hour to allow washou t o f any residual effects from exposure, bodyposition or testing.

After the 1 hour rest period, the second trial as designated by randomization w asperformed in the man ner of protocol outlined above. After the subjects second trial andwashout period, the experimental day was completed. As noted above, all 4 xperimentaltrials for each subject were completed ov er 2 different experimental da ys in order toavoid OC exposure twice in a single day (See EX HIBIT B for the experimental trialprotocol).

E. DATA COLLECTION AND ANALYSISDem ograph ic data were collected on the subjects age, weight, height and race.

The subjects weight and height were used to calculate body m ass index (BMI). Thesedata were used to stratify subjects as overweight (BMP-28kg/m2). Additional data were


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FINAL REPORT - OC pray and Positionfunction testing data were collected (FVC and FEV 1) and converted to a percentage ofpredicted (% predicted, denoted % predicted FVC and % predicted FE VI ) for eachsubject to allow for normalization for age, he ight and ace as per standard practice. 52753

Statistical Analysis. Analysis of Variance (ANO VA) for repeated measures withposition (sitting or restraint) and exposure (O C or placebo) as factors wa s performed on

all data to determine if any statistically significant differences existed betw een the fourexperimental trials. A probability value of less than 0.05 (after Bonferroni correction forindependent variables) was considered statistically significant. Data analysis wasperformed by means of a computerized statistical software package (Stata 6.0 forWindows, Stata Corporation).

An apriori power analysis determined that 32 subjects would be needed to detecta 10%difference in pulm onary function testing parameters if such a difference existedbetween the four trial groups.

Clinically, the data were analyzed on multiple levels. First, data were analyzed asabsolute values in comparison with known normal values. Hyp oxem ia, or abnormaloxygenation was defined a s a p 0 2 less than 85 mmHg or oxygen saturation less than


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FINAL REPORT - OCspray and Positionand pC02 levels) and PFT m easurements (YOredicted FVC and YO redicted FEV l) ,were com pared between the different exposure and position groups.

In addition, the data were analyzed rega rding questions related to the issues of OCspray and positional restraint. Data w ere stratified by BMI and potential for pulmonaryabnormalities as delineated above. An additional analysis was conducted on these g roupsto determine if any c linically significant differences occurred in these subjec ts.


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FINAL REPORT - OC pray andPositionIV. DETAILED FINDINGS

A. Study SubjectsThirty-seven (37) subjects from the training staff and cadets o f the San Diego

Regional Public Safety Training Institute were recruited and enrolled a s subjects for thisstudy. Two subjec ts were excluded prior to starting the study. One subject had fracturedhis ribs and w as unable to adequately perform spirometric pulmonary function testing.The other subject had a fractured arm mm obilized in a cast making it impossible to placethe sub ject in the restraint position.

The third subject was excluded after he experienced an adverse reaction duringhis first trial. Th e subject suffered a syncop al event (fainted) during arterial puncture andblood drawing (phlebotomy) which w as most likely due to vagal hyperstimulation.During this trial, the subject had been expose d to placebo spray and w as in the sittingposition when he fainted. This was his first trial and he wa s never expos ed to OC spraynor placed in the restraint position at any time during the study. His recovery wasuneventful and he suffered no lasting sequelae or injury.


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FINAL REPORT - OC pray and PositionJ

The 34 subjects completed a total of 136 separate trials (4 trials each). Of these, 8

trials were excluded from analysis because the sub ject did not adequately inhale (asmeasured by impedance monitoring) when exposed to OC spray. As a result, 128separate study trials were analyzed for purpose s of this study.

For the spirometric and pulm onary function testing data, an additional 4 rials

were excluded as testing did not meet Am erican Tho racic Society criteria fo rreproducibi li ty and ~ a r ia b i l i t y .~ ~or the arterial blood g as data, 2 trials were excludedbecause venous rather than arterial blood was sam pled. For the blood pressure data, 1trial was excluded du e to mechanical instrument error.

B. Effect o f OC Exposure in the Sitting PositionSpirometric Findings. In the sitting position, OC exposure did not result in a

statistically significant change in pulmonary function as measured by FV C and FE Vl .OC exposure also did not result in any clinically significan t abnormalities in pulmonaryfunction (as previously defined as below 80% of predicted values).

There was no difference in baseline '30 redicted FVC p rior to exposure in the


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FINAL REPORT - OC pray and Position1.5 minutes, and 102.3% (SD 8.6%; CI 99.2-105.5%) at 10 minutes after exposure (seeEXHIBIT C).

Similarly, there were no differences in % predicted FEV l between the OC andplacebo expo sure groups in the sitting position. For the placebo group, mea n baseline %predicted FE Vl was 100.1%(SD 9.3%; CI 96.7-103.4%); and for the OC group, 100.3%

(SD 9.1%; CI 97.0-103.6%). At 1.5 minutes after exposure, mean % predicted FEV l was98.9% (SD 9.6%; CI 95.6-102 .3%) for the placebo group, and 98.9% (SD 9.4%; CI 95.5-102.4%) for the OC group. At 10 minutes, mean % predicted FEV 1 was 99.2% (SD10.1% ; CI 95.6-102.8%) for the placebo group , and 99.0% (SD 9.5%; CI 95.6-102.5%) inthe OC group (See EXHIBIT D).

Oxygenation. OC spray exposure did not result in any statistically significantdifferences in oxygen ation (as measured by transcutaneous oxygen saturation and arterialp 0 2 levels) when compared to placebo in the sitting position. Moreo ver, there was noevidence of clinical hypoxemia (lower than normal amount of oxygen in the blood aspreviously defined as 0 2 saturation less than 95% or p 0 2 less than 85 mm Hg) w hile inthe sitting position after OC or placebo e xposure.


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FINAL REPORT - OC pray and Position92.9-100.6mmHg) f or the placeb o group, and 99.4 mmH g (SD 11.84mmHg; CI 95.0-103.7mmHg) for the OC group. Although this rise in p0 2 was not statisticallysignificant, it doe s correspond well to the observed fall in p C 0 2 levels in this group (seebelow) (SEE EXHIBIT E).

Ventilation an d C 0 2 Levels. Carbon Dioxide (C 02 ) levels decreased after OCcompared to placebo expos ure in the sitting position. Th is small, but statisticallysignificant finding sugges ts ventilation increased afte r OC exposure.

Mean end-tidal C 0 2 levels were 38.0 mmH g (SD 3.5mmHg; CI 36.8-39.2mmHg)for the placebo group and 38.2 mmH g (SD 4.22mmH g; CI 36.6-39.7mmHg) for the OCgroup at baseline prior to exposure. At 1 minute after exposure, mean end-tidal C 0 2 was36.8 mmHg (SD 4.3SmmHg; CI 35.3-38.3mmHg) for the placebo group, but dropped t o32.4 mmH g (SD 5.l m m Hg ; CI 30.5-34.3mmHg) for the O C group. At 5 minutes, m eanlevels were 36.5 mmH g (SD 5. lmmHg; CI 34.7-38.3mmHg) and 32.9 mmHg (SD5.8m mH g; CI 30.7-35.OmmHg) fo r the placebo and OC groups, respectively. At 9minutes, mean levels were 37.0 mmH g (SD 4.6mmHg; CI 35.4-38.6mmHg) and 35.2mmHg (S D 5.9mmHg; CI 33.0-37.4mmHg) respectively. Similarly, mean arterial p C 0 2


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FINAL REPORT - OC pray and Position68.7 bpm) at 5 minutes, and 60.3 bpm (SD 10.0; CI 56.9-63.8 bpm) at 9 minutes afterexposure. In the OC group, mean heart was 67.8 bpm (S D 11.3; CI 58.4-66.2 bpm ) atbaseline, 77.4 bpm (SD 13.1; CI 72.6-82.2 bpm) a t 1 minute, 69.0 bpm (SD 9.5; CI 65.5-72.5 bpm) at 5 minutes, and 64.6 bpm (SD 10.6; CI 60.7-68.5 bpm) at 9 minutes afterexposure (see EXHIBIT G).

Mean arterial pressure (MAP, one-third of systolic pressure plus two-thirds ofdiastolic pressure) remained significantly elevated in the OC group at 3 , 6 and 9 m inutesafter exposure in the sitting position. At baseline, mean M AP w as 101.OmmHg (SD11.6; CI 96.9-105.0 mmH g) in the placebo group and 103.4 mm Hg (S D 11 O; CI 99.3-107.4 mm Hg) in the OC group. At 3 minutes, mean MAP was 103.8 mmH g (SD 9.1; CI100.6-107.0 mm Hg) in the placebo group , but increased to 116.8 mm Hg (S D 12.8; CI112.2-121.5mm Hg) in the OC group. At 6 minutes, m ean MAP was 100.7 mmHg (SD10.4; CI 97.0-104.3 mmH g) and 112.1 mm Hg (SD 13.5; CI 107.1-1 17.0mmH g), in theplacebo and OC groups, respectively. At 9 minutes this difference remained , with meanM A P of 98.1 mm Hg (SD 10.2; CI 94.6-101.7mmHg) and 107.8 (SD 13.7; CI 102.7-112.8 mm Hg) in the two groups, respectively (See EXHIBIT H).


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FINAL REPORT - OC pray and Positiona baseline O f 99.7% (SD 9.4%; CI 96.4-102.9%), to 83.2% (SD 9.7%; CI 79.7-86.7% ) at1.5 minutes, to 83.7% (SD 10.3% ; CI 80.0-87.3%) a t 10 minutes into the restraintposition (see EX HIBITS C & D).

Exposure to OC made no statistical or clinical impact on pulmonary function inthe restraint position. For the OC group, mean % predicted FVC fell from a baseline of103.4% (SD 8.1%; CI 100.3-106.5%), to 87.5% (SD 7.3%; CI 84.7-90.3% ) at 1.5minutes and 87.2% (S D 7.3%; CI 84.3-90.0%) at 1 0 minutes. Similarly, mean YOpredicted FEV l fell from a baseline of 101.1% (SD 8.0%; CI 98.0-104.2% ), to 82.5%(S D 10.0% ; CI 78.7-86.3%) at 1.5 minutes and 82.0% (SD 1.6%; CI 78.8-85.2% ) at 10minutes after OC exposure in the restraint position (see EXH IBIT C & D).

Oxygenation. Similar to the results in the sitting position, OC exposure followedby restraint did not result in statistically significa nt differe nces in oxygen ation orevidence of hypoxem ia. In the placebo group, mean oxygen saturation was 99.4% (SD1 O%; CI 98 .1-99.7%) at baseline, 97.9% (SD 2.3%; CI 97.1-98 .7%) at 1 minute, 98.0%(SD 1.9%; CI 97.7-98.9%) at 5 minutes, an d 97.4% (SD 3.7% ; CI 96.1-98.6%) at 10minutes into the restraint position. In the OC group, mean oxygen saturation was 99.3%



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ventilation after OC. At baseline prior to exposure, mean C 0 2 levels were 37.7 mmHg(SD 4.0; CI 36.3-33.1 mmH g) and 36.3 m mH g (SD 7.7; CI 36.0-39.0 mm Hg) for theplacebo and restraint groups, respectively. At 1 minute after exposure, levels were 38.8mmHg (SD 4.1; CI 37.4-40.3 mmHg) in the placebo group, but decreased to 36.7 mm Hg(SD 6.4; CI 34.3-39.2 mm Hg) in the OC group. At 5 minutes, levels were 3 9.1 mmHg(SD 4.0; CI 37.7-40.5 mmH g) and 36.6 mm Hg (SD 5.4; CI 34.5-38.7) and at 9 m inutes,39.5 mmHg (SD 3.8; CI 38.2-40.8 mmH g) and 37.7 mm Hg (SD 4.7; CI 35.9-39.5mmH g), respectively. Similarly, mean arterial p C 0 2 levels at 8 minutes were 40.9mmHg (SD 4.3; CI 39.3-42.4 mmH g) in the placebo group, and 39.1 m mH g (SD 5.2; CI37.2-41.1 mm Hg) in the OC g roup (see EXHIBIT F).

Cardiovascular Parameters. As with sitting position, there was a slight increasein HR and larger increase in MAP after OC exposure in the restraint position. For theplacebo group, mean HR was 62.3 bpm (SD 11.3; CI 58.4-66.2 bpm ) at baseline, 70.4bpm (SD 10.9 bpm ; 66.5-74.2 bpm ) at 1 minute, 66.5 bpm (SD 12.2; CI 62.2-70.8 bpm)at 5 minutes, and 62.6 bpm (SD 8.6; CI 59.6-65.6 bpm) at 9 minutes. For the OC group,mean HR was 64.8 bpm (SD 8.4; CI 61.6-68.0 bpm ) at baseline, 71.1 bpm (SD 13.9; CI


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(S D 10.0; CI 95.6-102.6 mmH g) and 108.2 mmH g (SD 12.42; CI 103.5-1 12.9 mmH g),and at 9 minutes, 100.1 mm Hg (SD 11.52; CI 96.1-104.2 m mHg) and 110.0 mmHg (S D10.6; CI 106.0-1 14.1 mmHg), respectively (see EXH IBIT H).

D. Effects of Other FactorsThe effect of additional factors, body weight and the potential for underlying lung

abnormalities, was assessed.Body Weight. There were 7 subjects classified as overweight (BM1>28 kg/m2) in

this study. Spirom etric findings mirrored those for the entire study population. Mean %

predicted FVC were similar between placebo and OC groups in the sitting position(1 03.7% vs. 103.7% at baseline; 104.4% vs. 104.3% at 1 .5 minutes; 104.5% vs. 104.4%at 10minutes, respectively). Mea n % predicted FEV 1 were sim ilar between placebo andOC gro ups in the sitting position (1 02.8% vs. 102.9% at baseline; 103.0% vs. 104.3% at1.5 minutes; 103.0% vs. 102.5% at 10 minutes, respectively).

Mean % predicted FVC were also similar between placebo and OC groups in therestraint position w ith typical decreases in pulm onary function resulting from body

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FINAL - OC pray98.6% vs. 99.3% at 5 minutes; 99.3% vs. 98.7% a t 9 minutes, respectively). Results weresimilar for the restraint position (98.6% vs. 99.3% at baseline; 97.6% vs . 97.0% at 1minute; 97.0% vs. 98.4% at 5 minutes; 96.7% vs. 98 .0% at 9 minutes).

Interestingly, in th e overweight group, arterial p 0 2 levels revealed a slightlylower p0 2 level in the placebo group that imp roved with OC exposure (85.4 m mHg v s.10 1.6 mm Hg , respectively) in th e sitting position. In the restraint position, there was noimprovement (82.3 mmH g vs. 82.8 mm Hg, respectively).

Mean C 0 2 levels in the overweight group mirrored those found in the overallstudy population. In the sitting position, there was no evi den ce of hypercapnia, o rhypoventilation, with placebo or OC ex posu re (mean end-tidal C 0 2 levels of 38.4 vs.37.6 mm Hg a t baseline; 36.0 vs. 3 1.1 mm Hg at 1 minute; 36.1 vs. 3 1.1 mm Hg at 5minutes; 37.9 vs. 33.4 mmHg at 9 minutes; mean arterial p C 0 2 at 8 minutes of 41.6 vs.35.0 mmH g, respectively). In the restraint position, findings were similar (m ean end-

tidal C 0 2 levels of 38.0 vs. 37.8 mm Hg at baseline; 37.9 vs. 35.8 mm Hg a t 1 minute;38.7 vs. 36.4 mmHg at 5 minutes; 39.5 vs. 36. 8 mrnHg at 9 minutes; m ean arterial p C 0 2levels at 8 m inutes of 41.6 vs. 3 8.7 mm Hg, respectively).



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Mean arterial pressure markedly increased with OC exposure in both the sittingand restraint groups, similar to the finding s for the entire subject population (in the sittingposition: 108.8 vs. 1 07.7 mm Hg at baseline, 1 07.8 vs. 120.8 mm Hg at 3 m inutes, 106.0vs. 1 18.7 mmH g at 6 m inutes, 103.3 vs. 111.6 mmHg at 9 minutes; an d in the restraintposition: 104.9 vs. 1 05.1 mm Hg at baseline, 104.0 vs. 112.2 mmH g at 3 minutes, 102.3vs. 110.6 mm Hg at 6 minutes, 103.5 vs. 111.2 mm Hg at 9 m inutes for the placebo andOC groups, respectively).

Potentialfor Respiratory Abnormalities. Eight (8 ) subjects had eith er a history of lung

disease, such as asthma, history of smoking, or used a respiratory inhaler medication o n aregular basis. A separate analysis was performed o n this group and resulted in finding ssimilar to the overall subject population.

Pulmonary functio n testing revealed typical decline s related to body position, but

showed no differences between placebo and OC expo sure. In the sitting position, mean% predicted FVC were similar in the placebo and OC g roups (105.6 vs. 107.6% atbaseline, 106.2 vs. 105.4% at 1.5 minutes; 105.4 vs. 101.1YO t 10 minutes, respectively)



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Oxygenation in this group of 8 subjects was sim ilar to those of the overall sub jectpopulation. In the sitting position, there was no evide nce of hypoxemia (m ean oxygensaturations of 99.4 vs. 99.4% at baseline, 99.1 vs. 99.6% a t 1 minu te, 98.4 vs. 99.6% at 5minutes, 99.3 vs. 99.6% at 9 minutes; mean arterial p 0 2 at 8 minutes of 101 7 VS . 96.6mm Hg for the placebo and OC groups, respectively). In the restraint position, findingswere similar (mean oxygen saturations of 99.4 vs. 99.0% at baseline, 97.4 vs. 99.0% at 1minute, 98.0 vs. 98.5% at 5 minutes, 95.9 vs. 98.8% at 9 minutes; mean arterial p 0 2 at 8minutes of 91 O vs. 90.0 mmHg, respectively).

C 0 2 levels for these 8 subjects also were sim ilar to those found for the overallstudy population. In the sitting position, there was no evidence of hypercapnia orhypoventilation (mean end-tidal C 0 2 levels of 38.1 vs. 37.9 mm Hg at baseline, 37.8 vs.31.6 mmHg at 1 minute, 38.3 vs. 33.7 mm Hg at 5 minutes, 37.4 vs. 36.6 mm Hg at 9minutes; mean arterial pC 0 2 at 8 minutes of 40.4 vs. 38.0 mm Hg for the placebo and OC

groups, respectively). In the restraint positio n, findings wer e similar (38.0 vs. 39.0mmH g at baseline, 39.3 vs. 37.7 mmH g at 1 minute, 38.8 vs. 38.0 mmHg a t 5 minutes,39.3 vs . 39.5 mm Hg at 9 minutes; mean arterial pC 0 2 at 8 minutes of 40.9 vs. 42.2



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vs. 120.8 mm Hg at 3 minute, 105.7 vs. 120.5 mm Hg at 6 minutes, 101.3 vs. 114.5 mm Hgat 9 minutes, respectively).

In the restraint position, HR findings were variable (61.6 vs. 63.2 bpm at baseline,77.7 vs. 76.5 bpm at 1 minute, 73.5 vs. 68.3 at 5 minutes, 64.3 vs. 65.8 bpm at 9 minutesfor the placebo and OC groups, respectively), whereas MAP increased with OC exposure(106.5 vs. 106 .9 mmH g at baseline, 110.3 vs. 115.7 mm Hg at 3 m inutes, 104.6 vs. 114.2at 6 minutes, 107.1 vs. 115.6 at 9 minutes, respectively).

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V. ANALYSIS AND DISCUSSION

Th e goal of this study wa s to assess the safety of O C exposure by itself and incomb ination with physical restraint. Specifically, we sought to determine if OC sprayinhalation resulted in significant respiratory co mp rom ise such that individuals might be atrisk for significant injury and even death.

We performed a randomized, cross-over controlled laboratory study in humansubjects comparing the effects of OC spray and placebo followed by the sitting andrestraint positions. Subjects perform ed 4 different trials (varying exposure and position)such that each served as their own control. Th e cross-over design eliminated potentialconfound ing factors between control and experimental groups. In addition,randomization eliminated potential differences that may have resulted fro m the sequenceof trials.

This study had 2 main objectives as well as 3 additional objectives addressingrelated issues regarding the physiolog ic effects of OC exposure.



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1.5 and 10 minutes after ex posure between the OC and placebo groups. Clinically, thesespirometric parameters remained w ithin the range of normal (above 80%of predicted) at1.5 an d 10 minutes after OC exposure and inhalation.

Moreo ver, there was no difference between OC and placebo groups in terms ofoxygenation, and no evidence of hypoxemia to suggest respiratory com prom ise after O Cinhalation. There was also no evidence of hypercapnia, or C 0 2 retention to suggest poorventilation, after OC inhalation. In fact, C 0 2 levels were lower in the OC grou p,suggesting an increase in v entilation after OC inhalation.

Our findings are consistent with a number of other hum an clinical studies thathave exam ined the effect of nebulized capsaicin, the active agent of OC spray, onrespiratory function. As discussed above, these studies reported transient changes inairway resistance, but no evidence of sustained bronchoconstriction beyond 1-2 minutesafter the exp osure. 0, 21,22

While nebulized capsaicin has been studied extensively, this study assessedpulmonary and respiratory function after exposure to a co mm ercially-available OC sprayused by law enforcement agencies nationwide. In finding no evidenc e of respiratory



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Ou r findings concerning the restraint position we consistent with our previouswork on respiratory function and restraint. In our earlier studies, we found declines inpulmonary function (FVC and F E V l) with restraint, but no evidence of hypoxemia,hypercapnia or hypoventilatory respiratory d y s f u n ~ t i o n . ~ ~

In this study, we found no evidence that OC exposure resulted in any additionalchange in respiratory function in the restraint position. In both the OC and placebogroups, we saw declines in % predicted FVC and % predicted FE Vl once subjects wereplaced in the prone maxim al restraint position. Wh ile these declines indicate a restrictivepulmonary function pattern, mean spirometric measurements remained within the normalrange. Moreover, there were no statistical differences betw een the OC and placebogroups relative to these d eclines in YO redicted FVC and YO redicted FEVl .

In additionally, just as we had found with in the sitting position, there w as nodifference in terms o f oxygenation in th e restraint position between th e OC and placebogroups. There was also no difference in C 0 2 levels between the two groups in therestraint position, aga in suggesting that OC exp osu re had no adverse effect on ventilatory


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FINAL REPORT - OC pray and PositionIn this study, we found OC exposure resulted in a small increase in heart rate after

exposure when com pared with placebo. While statistically significant, this difference isof probably of no clinical importance as m ean heart rates for all groups, regardless ofexposure or position, remained in th e 60 to 80 bpm range, well within normal limits.

Mean arterial pressure however, was significantly elevated after OC exposurewhen comp ared to placebo in both the sitting and restraint positions. This difference,though small, persisted at 3 , 6 , an d 9 minutes after exposure.

The cardiovascular effects of capsaicin remain unclear and complex.s4 Animalstudies have shown cap saicin can result in both hypertension and h y p ~ t e n s i o n . ~ ~ ~ ~Accordingly, some investigators contend that capsaicin can precipitate bradycardia andhypotension, similar to the Bezold-Jarrish reflex.57 Others argue that OC exposure causesacute elevations in blood pressure, leading to potential hypertensive ~ r i s e s . ~ur studyalso suggests an elevation in blood pressure. However, the etiology of this elevationremains uncertain and may simply result from the discomfort and pain associated withOC exposure.

4. Whether body size and weight influence the effects of OC spray in regards to

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positions. There was also no evidence of hyp ercapnia or hypoventilation f or this groupof subjects after OC inhalation in either the sitting o r restraint positions.

Interestingly, while transcutaneous measurem ents of oxygen saturation werenormal regardless of exposure or position, subjects in this group revealed a mild drop inp 0 2 levels (on arterial blood gas sam pling) in both sitting and restraint positions afterplacebo exposure. Arterial oxygenation improved with OC exposure in the sittingposition, but did not cha nge in the restraint position.

Morbid obe sity can lead to a restrictive pulmonary dysfunction and increasedairway resistance, as well as hypo xemia and hype rcapnia, particularly w hen associatedwith obstructiv e sle ep apnea.* In our study, no subjects were m orbidly obese (no BM I> 32 kg/m2). Of those who were overweight (BMI > 28 kg/m2), there was no evidenceof restrictive dysfunction in the sitting or even restraint position with OC o r placeboexposure. In this group, OC exposure did not hypox emia or hypoventilation in either thesitting or restraint position, but did see m to imp rove oxygenation for the sitting position.Clearly, however, these conclusions must be tempered by the small num ber of subjectsstudied in this subanalysis and the fact that none of our subjects were m orbidly obese.



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In this study, we found no evidence that OC spray inhalation and exposureresulted in respiratory compromise in subjects with the potential for pulmonaryabnormalities (history of lung disease, asthma, smoking, and respiratory inhalermedication use). In this subgroup, we found that OC exposure had no effect onpulm onary function in the sitting or restraint positions. Th ere was also no evidence ofhypoxemia, hypercapnia or hypoventilation after OC inhalation for this group in eitherthe sitting or restraint positions.

i

The effect of capsaicin in those with lung disease, particularly asthm a, remainscontroversial. It has been suggested that asthmatics may have increased responsivenessto the respiratory effects of capsaicin and OC, possibility d ue to increased sensitivity ofnerves in the lung parenchyma.26.60Other clinical studies sugg est there is little or nodifference in the effects of capsaicin on airway resistance and bronchoconstriction insmokers, asthmatics or those with respiratory infections.20y61 ur findings from this smallsubgroup of subjects exposed to OC seem to support the latter contention.

While our results suggest OC exposure does not result in respiratory dysfunctionin those with potential respiratory abnorm alities at baseline, it is important to note that



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encountered in the law enforcement field setting where OC spray and positional restrain tare em ployed.

Field subjects are often in a state of extreme agitation and excited delirium as aresult of underlying psychiatric disease or intoxication from recreational drugs. Subjec tsare often involved in violent, physical strug gles prior to, during and after the use o f OCspray or positional restraint. There has been specu lation that subjects in the field undergoextreme levels of exertion leading to exhaustion that may impact pulmonary function.While previous studies have attempted to replicate exertion and ~ t r u g g l e , 4 ~ , ~ *t is unlikelythat all conditions, particularly the physiolo gic effects of psycholog ical stress,psychological stress and trauma that oc cur in the field could be reproduced in thelaboratory.

Moreover, as this study focused on inhalational exposure, all su bjects had gogglesto reduce ocular OC exposure. Eye irritation and pain from OC may exacerbate thephysiologic stress of field subjec ts, which w as no t assesse d by this study. In addition,when restrained, subjects were placed o n a m edical exam ination table rather than on ahard surface that often occurs in the field setting.



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second that can occur in the field setting. Mo reover, we did not study exposures fromclose distances, which also may occur in the field. How ever, spray distances less than 5feet generally do not allow for adequate aerosolization of OC and likely reduce theamou nt of inhalational exposure.

Exposure in the box was limited to 5 secon ds while in th e laboratory. Wh ile thismay seem a short period of time, spray in the field usually occurs in an open settingwhere OC dissipates rapidly. Moreo ver, by containing the spray within the exposure box,it is likely that subjects were exposed to a much higher concentration o f capsaicin thanmight have occurred in the open air. Th e concentration o f active capsacinoids(approximately 26 m g delivered per spray into a 2 x lo6 cm3 space) in our study wassimilar if not higher than other clinical stu dies on capsaicin inhalation.

W e did not study repeated OC spray exposures that com mon ly occur in the fieldsetting. We also used an aerosol form of OC spray, rather than the liquid or foam formsthat are also used by law enforcement agencies. W e believe the aerosol form was mor elikely to be inhaled than other forms an d, thus more appropriate for our study on therespiratory effects of OC.

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Finally, w e must again stress the limited nature of the additional analysesperformed on the subgroups of subjects w ho w ere overweight o r had potential respiratoryabnormalities. These groups were small in numb er and ou r analyses lacked sufficientstatistical pow er to ma ke any definitive conclusive findings. Mo reover, as our studypopulation w as recruited from training cadets at the local police academy, our subjectswere generally healthy, you ng individuals.

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D. IMPLICATIONS FOR LAW ENFORCEM ENTThis study provides scientific and physiologic data assessing the safety of OC

spray by itself and in combination with positional restraint, comm only used by la wenforcement personnel to subdue violent, dangerous suspects in the field. This studyfocused on two force methods, nam ely OC and prone m axim al restraint, directlyassociated with law enforcement procedures. Findings from this study directly impactupon policing practices and policies regarding the use of these force options.

This study supports the contention that OC spray inhalation does not representany significant risk to subjects in terms of respiratory and pulmonary function eve n whencom bined with positional restraint. In this study, OC exposure did not result in anyevidence of pulm onary dysfunction, hypoxemia, o r hypoventilation, in either the sittingor restraint positions. These findings also applied to subgroups of overweight subjectsand those with potential respiratory abnorm alities.

This study provides new information on the issue of in-custody deaths.Determining a cause of death in these cases is often difficult as there a re f ew pathologicfindings at a ~ t o p s y . ~ ~ccordingly, in-custody deaths have been attributed to a number

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enforcement personnel som e measure o f comfort in the know ledge that they areemploying force methods, namely OC spray, that have be en tested and found safe onhumans in clinical studies.

In addition, these findings may imp rove the relatio nship betw een local agenciesand their communities as the general public will be aware that officers in theircomm unities are employing force me thods that have been rigorously studied in a clinicallaboratory on human subjects. More over, questions regarding OC use in case s of custodydeaths will less likely contribute to the public controversy and contentiousness that oftenfollows these cases.

Second, this study will aid law e nforcement agencies when facing accusations ofexcessive force based on the unfounded conten tion that OC exposure results inrespiratory compromise. Data from this study will assist law enforcement agencies indeterring and defending themselv es from litigation that can negatively im pact the well-being and morale of their agencies as a w hole and, m ore directly, their personnel andofficers in the field.

Third, on a general public policy leve l, this study provide s solid scientific

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CONCLUSIONS

We conducted a randomized, cross-over controlled study investigating the effectsof OC inhalation and prone maxim al restraint on respiratory function in hum an subjects.In our subjects, OC exposure resulted in no evidenc e of pulmona ry dysfunction,hypoxemia, or hypoventilation when compared to placebo in both the sitting and restraintpositions. Our findings support the contention that OC spray use by law enforcementpersonnel in the field does not result in resp iratory com prom ise or increased risk fo rrespiratory arrest and death in exposed subjects.



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VI. ENDNOTES Granfield J, O m e n J, Petty CS: Pepper spray and in-custody deaths. Executive Brief.Science & Technology. International Association of Chiefs of Police & NationalInstitutes of Justice, March 1994.Bunting S: First death attributed to O C occurs in North Carolina. ASLET Journal1993:13 .Steffee CH, Lantz PE, Flannagan LM, Thompson RL, ason DR: Oleoresin capsicum(pepper) spray and in-custody deaths. Am J Forensic Me d Path01 1995; 16(3):185.Am erican Civil Liberties Union: Pepper spray update: more fatalities, more questions.ACLU o f Southern California, 1995.Ross D, Siddle B: Use o f force policies and training recommendations: based o n the

medical implications of oleoresin capsicum. PPC T Research Review 1996.Reay D T, Fligner C1, Stilwell AD, et al: Positional asphy xia during law enforcem enttransport. Am J Forensic M ed Pathol 1992; 13:98.DiMaio DJ, DiMaio VJ: Forensic Pathology. New York; Elsevier, 1 989.Mittleman RE, Davis JJ: Deaths from custody ? Forensic Pathology 1991; 22(2):98.Luke JL, Reay DT : The perils o f investigating and certifying deaths in police custody.Am J Forensic Med Pathol 1992; 13:90.

l o Lifschults BD, Donoghue ER : Deaths in custody. Legal Med 1991; 45.



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l 5 Haas JS, Whipple RE, Grant PM, Andersen BD: Chem ical and elemental comparisonof two form ulations of oleoresin capsicum . Science & Justice 1996; 37( 1): 15.l6 Fox AJ: M echanisms and medulation of capsaicin activity on airway afferent nerves.Pulm Pharmacol 1995; 8:207.l7 Winograd HL : Acute croup in an older child: an unu sual toxic origin. Clin Pediatr1977; 16:884.l 8 Lundberg JM, M artling C RY aria A: Substance P and capsaicin-induced contraction ofhuman bronchi. Acta Physiol Scand 1983; 119:49.l9 Hansson L, W ollmer P, Dahlback M , Karlsson JA: Regional sensitivity of humanairways to capsaicin-induced coug h. Am Rev Respir Dis 1992; 145: 1 191.2o Fuller RW, D ixon CM S, Barnes PJ: Bronchocon strictor response to inhaled capsaicinin humans. J Appl Physiol 1985;58(4):1080.21 Blanc P, Liu D, Juarez C, Boushey HA: Cough in hot pepper workers. C hest 1991;99:27.22 Collier JG , Fuller RW : Capsaicin inhalation in man and the effects of sodiumcromoglycate. Br J Pharm ac 1984; 81 113.23 Lamm ers JJ, Minette P, McC uscker MT, Chung KF, Barnes PJ: Nonad renergicbronchodilator m echanisms in normal human subjects in vivo. J Apple Physiol 1988;64(5): 18 17.

Fuller R W : Pharmacology of inhaled capsaicin in hum ans. Resp Med 1991; 85(supp4



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~ ~~~ ~

29 Lundgren DE: O leoresin capsicum (OC) usage reports: sum mary information. Reportof the California State Attorney General, March 1996.30 Watson WA, Stremel KR, W estdorp EJ: Oleoresin capsicum (cap-stun) toxicity fromaerosol exposure.Ann Pharmacother 1996; 30:733.31 Jett MB: P epper spray training for safety. FBI Law Enforcement Training Bulletin.Federal Bureau of Investigation, 1997.32 Burgreen B: Final Report of the Custody Death Task Force. Chief of Police, San Dieg o.Police Department, 1992.33 Krosch C: S ome in-custody deaths cited as preventable. Law Enforcement Quarterly1992: 15.34 Bell MD , Rao VJ, Wetli C V, et al: Positional asphyxiation in adults: a series of 30cases from the Dade and Broward county Florida medical examiner offices fiom 1982 to1990. Am J Forensic Med Pathol 1992; 13:101.35 Katz L: Ac cide ntal strangulation from vest restraints. JAM A 198?;257:2032.36 Dube AH , Mitchell EK: A ccidental strangulation from vest restraints. JAM A1986;256:2725.37 Hirsh CS: Restraint asphyxiation. Am J Forensic Med Pathol 1994;15:266.38 Emson H E: Death in a restraint jacket from mechanical asphyxia. Can Med Assoc J1 9 9 4 35 1 985.39 OHalloran RL, Lewm an LV: R estraint asphyxiation in excited delirium. Am J

FINAL REPORT - OC pray andPosition


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44 Hamm ond MD, Gale GE, Kapitan KS, Ries A, W agner PD: Pulmonary gas exchangein humans during exercise a t sea level. J App l Physiol 1986;60(5): 1590.45 Whipp BJ, Wasserman K: Alveolar-arterial gas tension differences during gradedexercise. J App l Physiol 1969;27(3):361.46 Chan TC , Vilke GM, Neuman T, C lausen JL: Restraint position and positionalasphyxia. Ann Eme rg Med 1997; 30:578.

Clausen JL: Pulmonary b c t i o n testing. In: Bordow, Moser, eds. Manual of Clinical7Problems in Pulmona ry Medicine. 4" ed. Boston, MA : Little Brow n; 1996:9.48 Schmidt MA, Snowden T: T he effects of positional restraint on heart rate and oxygensaturation. J Emerg Med 1999;17(5):777.49 Rogers C, R ussell MA, Eckstein My allon WK, Aguilar G: Post-exercise recoveryduring four-point restraint. Unpublished da ta.50 Ray CS, Sue DY, Bray G, Hanse JE, W asserman K: Effects of obesity on respiratoryfunction. Am Rev Resp Dis 1983;128:501.5 1 Lazarus R, Sparrow D, Weiss ST: Effects o f obesity and fat distribution on ventilatoryfunction. Chest 1997; 111 891.52 American ThoraCIc Society: Standardization of spirometry: 1994 update. Am J RespirCrit Care Med 1995; 152:1107.53 Morris JF : Spirometric standards for healthy, non-smoking adults. Am Rev Respir Dis1971; 103:57.

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59 Gold AR, Schwmtz AR, Wise RA, Sm ith PL: Pulmonary function and respiratorychemosensitivity in moderately obese patients with sleep apnea. Chest 1993; 103: 1325.6o Spina D: Airway sensory nerves: a burning issue in asthma? Thorax 1996; 51:335.

OConnell F, Thomas VE, Studham JM , Pride NB, Fuller RW: Capsaicin coughsentivity increases during upper respiratory infection . Respiratory Medicine 1996;90(5):279.

EXHIBIT A


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Exposure Box (2 views)

EXHIBIT B


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Trial Studv Procedure

TimeBaseIine/Preparation

0 time

5 seconds

I minute1.5 minutes3 minutesj minutes6 minutes8 minutes

9 minutes

ProcedureTrial exposure (OC or Placebo) and position (Sitting or Restraint) determined.Baseline Pulmon ary Function Testing (FVC and FEV 1) performed.Continuous m onitoring devices placed o n Subject.Baseline oxyg en saturation, end-tidal C 0 2 , heart rate and blood pressure recorded.Subject placed in H oodExp osure Box1 second of OC or placebo spray delivered into box.Impedance monitoring assesses ins piratiodexp irationSubject removed from H oodEx posure BoxSubje ct placed in position (Sitting or Restraint).Oxyg en saturation, end-tidal C 0 2 level and heart rate recorded.Pulmonary Function Testing (FVC and FE V1) performed.Bloo d Pressure recorded.Oxygen saturation, end-tidal C 0 2 level and heart rate recorded.Bloo d Pressure recorded.Arterial b lood gas sam ple drawn from radial artery at wrist.pH, pC 02 , and p0 2 levels determined.Oxy gen saturation, end-tidal C 0 2 level and heart rate recorded.Blood Pressure recorded.


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Exhibit C: FVC by Exposu re and Position

7-- -Baseline

// OC / restraint

.-_______ ~~~ ~~~U OC / restraint0 Placebo / restraintU O C / sit

Placebo / sit~

Placebo / sit/ sit/ restraint

1 min 710 min

U.S. Department of Justice.of the author(s) and do not necessarily reflect the official position or policies of thehas not been published by the Department. Opinions or points of view expressed are thoseThis document is a research report submitted to the U.S. Department of Justice. This report


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Exhibit D: F E V I by Exposure and Position

120%

100%

8oyo-I60%

40%

20 %

0% ---

0OC / restraint0 lacebo I restraintOOC / sit

Placebo I sit_ _ - ~

Placebo I sitsit/ restraint

t-- 4- .,

10 m inminasel ine



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1101051009590858075706560

Exhibit E: Oxygenation by Expo sure and Position

~ ~+ lacebo / sit-%- Placebo / restraint+O C / sit*OC / restraint-

I

Baseline I min 5 min 9 min ABG



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nCDI

e

12 0

11 5

110

105

100

95

90

85

80

Exhibit H: Blood Pressure by Expo sure and Position

-- __ ~ _ _ - ~ ~+ lacebo / sit+-Placebo / restraint+OC / sit+OC / restraint_ - ~ ~

Baseline 1 minI

5 min 9 min



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45

40

35

30

25

20

15

10

5

0

Exhibit F: Ventilation ( C 0 2 levels) by Exposure and Position

-+Placebo / sit-m- Placebo / restraint+OC / sit*OC I restraint.._ __ _- - - - - -

Baseline 1 min 5 minI

9 min ABG



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90

80

70

60

50

40

30

20

10

0

Exhibit G: Heart Rate by Exposure and Position

. _ _ _ _ _ _ _ _ _ _ ~ _ _ -+ lacebo / sit+- lacebo / restraint+O C / sitJtOC / restraint-~ __

BaselineI

1 min 5 min 9 min


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Pepper Spray Government Study