Emergency Ventilatory Management of the Critically Ill ...doctorfowler.com/www/lectures/emstoday2005ventilation.pdf · Rate: 6 breaths x min-1 (2 nd measurement ) one respiratory

Emergency Ventilatory Management Emergency Ventilatory Management of theof the Critically Ill Critically Ill andand Injured:Injured:

Elemental or Detrimental?Elemental or Detrimental?

Presented at EMS TodayMarch 20, 2005

Presented at EMS TodayMarch 20, 2005

http://www.docudesk.com

Copyright 2005 Ray Fowler MD, FACEPCopyright 2005 Ray Fowler MD, FACEPRay Fowler MD, FACEP

www.utsw.wswww.utsw.wswww.utsw.ws

That Brings Us to That Brings Us to TodayToday’’ s s

Sacred CowSacred Cow……

the

A-B

-C’s

!

Wha

t Abo

ut th

e“B”

Par

t?

Ass

iste

d B

reat

hing

with

PP

V

Res

cue

Bre

athi

ng...

Is It

Rea

lly N

eces

sary

?

Q: What are the Typical Teachings & Current National

Protocol Standards?

Q: What are the Typical Teachings & Current National

Protocol Standards?

A: 10-15 ml/kgTidal Volume &

15-20breaths/min Respiratory Rate

A: 10-15 ml/kgTidal Volume &

15-20breaths/min Respiratory Rate

Why

Do

We

Why

Do

We

Ven

tilat

e?V

entil

ate?


Oxygen-> lungs -> alveoli -> blood

muscles + organs

Oxygen

cells

Oxygen

Oxygen+

Glucose

energy

CO2

blood

lungs

CO2

breath

CO2

Oxygen and CO2Oxygen and CO2


Carbon dioxide physiology


CO2 + H2O H2CO3 H+ + HCO3-




• 0.03% concentration in air• Resting adult produces

2.5 mg/kg/min• In a 70 kg adult, that is about

175 mg per minute, or about 4% of a teaspoonful

• 0.03% concentration in air• Resting adult produces

2.5 mg/kg/min• In a 70 kg adult, that is about

175 mg per minute, or about 4% of a teaspoonful




• Transported in blood– 60-70% bicarbonate ion after

conversion in RBCs using carbonic anhydrase

– 20-30% bound to proteins (e.g., Hb)– 5-10% in physical solution (PCO2)

• Cleared by alveolar ventilation


Alveoli: The Place Where Gas Exchange Happens

Alveoli: The Place Where Gas Exchange Happens

OxygenationOxygenationvs.vs.

VentilationVentilationSaturating Red CellsSaturating Red Cells

vs.vs.

Clearing COClearing CO22

OxygenationOxygenation

Air MovementAir Movementandand

Blood FlowBlood Flow

THUS! CyanosisTHUS! Cyanosis……

An Air Movement ProblemAn Air Movement Problemoror

A Circulation ProblemA Circulation Problem

Wha

tW

hat ’’ s

an

Ade

quat

e T

idal

Vol

ume?

s an

Ade

quat

e T

idal

Vol

ume?

IT DEPENDS ON THE IT DEPENDS ON THE CLINICAL SITUATION!!CLINICAL SITUATION!!

10 m

l per

kg

(Int

ubat

ed, N

o P

EE

P, N

o D

iffus

e Lu

ng In

jury

)

Ven

tilat

ion

Ven

tilat

ion

Tid

al V

olum

eT

idal

Vol

ume

xx RR

RR

““ Ven

tilat

ion

Ven

tilat

ion

””

ME

AN

SM

EA

NS

RA

TE

!!R

AT

E!!

How

Fas

t H

ow F

ast

Sho

uld

You

S

houl

d Y

ou

Bre

athe

The

m?

Bre

athe

The

m?

Need to VentilateNeed to Ventilate

••COCO2 2 Production Production (depends upon O(depends upon O2 2 CConsumption onsumption

&& Venous ReturnVenous Return))

Hig

h V

entil

ator

y D

eman

d...

Hig

h V

entil

ator

y D

eman

d...

But Also:But Also:in very low flow statesin very low flow states

Oxygen ConsumptionOxygen ConsumptionBecomes Dependent Becomes Dependent onon

Oxygen Delivery...Oxygen Delivery...

For

Exa

mpl

e, C

PR

Cas

es...

Cardiac ArrestCardiac Arrest•• Little OLittle O 22 Delivery Delivery

& Consumption& Consumption

•• Little COLittle CO 22 Production Production & Venous Return& Venous Return

...Little Need to Ventilate...Little Need to Ventilate

0%

20%

40%

60%

80%

100%

120%

OO22 DeliveryDelivery( ml/min/kg )( ml/min/kg )

10 20 30 40

OO22MetabolizedMetabolized

(% of (% of baseline)baseline)

0%

20%

40%

60%

80%

100%

120%

A

B

OO22 DeliveryDelivery( ml/min/kg )( ml/min/kg )

10 20 30 40

COCO22ProductionProduction

(% of baseline)(% of baseline)

8 br

eath

s / m

in

Car

diac

Arr

est…

.

…Li

ttle

CO

2 E

xcre

tion

CP

R

Pul

ses

Ret

urn

Take HomeTake Home……

Ventilation Ventilation

Should Match Should Match PerfusionPerfusion……

The

“C

PR

Dile

mm

a”

Chest Compressions Chest Compressions & &

Coronary Perfusion PressureCoronary Perfusion Pressure5:15:1 RatioRatio

15:2 Ratio

20 mmHg20 mmHg

20 mmHg20 mmHg

40 mmHg40 mmHg

In Video Study of Lay Individuals Recently Taught 15:2 CPR ….

In Video Study of Lay Individuals Recently Taught 15:2 CPR ….

“Reality” CPR “Reality” CPR

…Took 15-16 Seconds to Deliver the2 Breaths

…Took 15-16 Seconds to Deliver the2 Breaths

Is There Evidence Is There Evidence That We Can That We Can

Breathe Less Often?Breathe Less Often?

Sanders, Sanders, et alet al•• 15:215:2 ((e.g.,e.g.,standard CPRstandard CPR))

•• 50:550:5 ((e.g.,e.g.,Great BritainGreat Britain))

•• CCCC ((chest compressionschest compressionsonlyonly))

•• 4 4 minmin CC CC onlyonly; ; thenthen 100:2100:2Porcine model of four different CPR techniquesAnnals of Emergency Medicine, Dec. 2002, pp 553-62Porcine model of four different CPR techniquesAnnals of Emergency Medicine, Dec. 2002, pp 553-62

Neurological Outcomes...Neurological Outcomes...•• 4 4 minmin CC CC onlyonly; ; thenthen 100:2100:2

----Did Significantly Better thanDid Significantly Better than

15:215:2 (e.g., standard CPR)(e.g., standard CPR)

•• CCCC (chest compression only) (chest compression only)

----Did Much WorseDid Much WorseAnnals of Emergency Medicine, Dec. 2002, pp 553-62Annals of Emergency Medicine, Dec. 2002, pp 553-62

Neurological Outcomes...Neurological Outcomes...•• CONCLUSIONCONCLUSION : In this experimental model of : In this experimental model of

bystander CPR, the group receiving bystander CPR, the group receiving compressions only for 4 minutes followed by a compressions only for 4 minutes followed by a compressioncompression--ventilation ratio of 100:2 achieved ventilation ratio of 100:2 achieved better better neurologicneurologic outcome than the group outcome than the group receiving standard CPR and CCreceiving standard CPR and CC--CPR. CPR. Consideration of alternative chest compressionConsideration of alternative chest compression--ventilation ratios might be appropriate.ventilation ratios might be appropriate.

Annals of Emergency Medicine, Dec. 2002, pp 553-62Annals of Emergency Medicine, Dec. 2002, pp 553-62

Sources of Sources of Ventilation:Ventilation:

•• Active Positive Pressure Active Positive Pressure

•• Chest CompressionsChest Compressions

•• GaspingGasping ((AgonalAgonal Breaths)Breaths)

Stopping to Breathe...Stopping to Breathe...

...Interrupts...InterruptsChest CompressionsChest Compressions

Idea

lC

PR

Idea

lC

PR

Rea

lC

PR

Rea

lC

PR

71%

19%

58%

42%

Normal BreathingNormal Breathing……•• Generates Negative IntraGenerates Negative Intra--

thoracic Pressurethoracic Pressure•• Pulls Lungs Open in a Pulls Lungs Open in a Specific Specific

ArchitectureArchitecture•• Enhances Venous Return Enhances Venous Return and and

Cardiac PreloadCardiac Preload

Ass

iste

d B

reat

hing

with

PP

V

PPVPPV……•• Generates Positive Generates Positive

IntrathoracicIntrathoracic PressurePressure•• Pushes Lungs Open in a Pushes Lungs Open in a

MaldistributiveMaldistributive MannerManner•• Diminishes Venous Return Diminishes Venous Return

and Cardiac Preloadand Cardiac Preload

PPV PPV Cardiovascular EffectsCardiovascular Effects

•• Obstructive Lung DiseaseObstructive Lung Disease•• HypovolemiaHypovolemia•• Circulatory CompromiseCirculatory Compromise

Worsened By...Worsened By...

So

Let’s

S

tudy

It!!

It’s

Not

Roc

ket

Sci

ence

!!

Dispatch Assisted CPR Instructions

Compressions Alone

vs

Standard ABC’s

Com

pres

sion

sA

lone

14.7

%vs

Sta

ndar

d

AB

C’s

10.4

%

Sur

viva

l...

But

Doe

s T

his

App

ly to

Chi

ldre

n?T

hink

Hyp

oxia

!!

How About How About Hypovolemic Hypovolemic

Patients?Patients?

Depends!Depends!

<---Breaths

Measuring Coronary Perfusion Pressure

Ventilated Pigs with Moderate Hemorrhage

Rate: 6 breaths x min-1 (2nd measurement)

one respiratory cycle= 10 sec.

Rate: 12 breaths x min-1

one respiratory cycle = 5 sec

s

Time-Averaged Coronary Perfusion Pressure = Area Under the Curve (in Pink)

RR = 6 / min RR = 12 / min

AufderheideAufderheide Study Study of Paramedicsof Paramedics

•• Averaged Averaged 3737±± 44 breaths/minbreaths/min

•• ReRe--trained at 12 / mintrained at 12 / min

•• Averaged Averaged 2222±± 33 breaths/minbreaths/min

CONCLUSIONS:Despite seemingly adequate training,

professional rescuers consistently hyperventilated patients

during out-of-hospital CPR.

CONCLUSIONS:Despite seemingly adequate training,

professional rescuers consistently hyperventilated patients

during out-of-hospital CPR.

And on the Road And on the Road to the to the

22nd Century...22nd Century...

…P

hren

icN

erve

Pac

emak

er?

Insp

irato

ryIm

peda

nce

Thr

esho

ld V

alve

-12

cm

H2O

HB

OC

HB

OC

-- 201

201

Let

Let ’’

s do

a

s do

a

Cas

e S

tudy

Cas

e S

tudy

Case #1Case #1……

•• 24 24 yoyo Male, Involved in MVCMale, Involved in MVC•• Altered MSAltered MS•• PERLA PERLA (but sluggish),(but sluggish),ThrashingThrashing•• 80/60, HR 130, pale80/60, HR 130, pale

Case # 1Case # 1……

•• Chest wall tenderChest wall tender•• Diminished BS on Right, dullDiminished BS on Right, dull•• Tender abdomenTender abdomen

Case # 1Case # 1……

•• Sick or not sick?Sick or not sick?•• REAL SICK, or REAL SICK, or kindakinda sick?sick?

Remember!!Remember!!Normal BreathingNormal Breathing……

•• Generates Negative Generates Negative IntrathoracicIntrathoracic PressurePressure

•• Pulls Lungs Open in a Pulls Lungs Open in a Specific ArchitectureSpecific Architecture

•• Enhances Venous Return Enhances Venous Return and Cardiac Preloadand Cardiac Preload

SO?????SO?????

How to assist How to assist ventilation ventilation

on this guy??on this guy??

MoribundMoribund Trauma Pt.Trauma Pt.

•• Little OLittle O 22 Transport Transport && ConsumptionConsumption

•• Little COLittle CO 22 Production Production && Venous ReturnVenous Return

Little Need to VentilateLittle Need to Ventilate

And ThereAnd There’’ s a Key s a Key Problem...Problem...

Positive Pressure Breaths Positive Pressure Breaths CanCanImpair Cardiac Output...Impair Cardiac Output...

...in the Face of Severe ...in the Face of Severe Circulatory CompromiseCirculatory Compromise

Moribund Trauma Moribund Trauma PatientPatient

•• Adequate Adequate Tidal VolumeTidal Volume

•• BreathBreath q 7 q 7 -- 10 seconds10 seconds

Tha

nk y

ouT

hank

you

for

your

kin

dfo

r yo

ur k

ind

atte

ntio

n!!

atte

ntio

n!!

ww

w.U

TS

W.w

sw

ww

.UT

SW

.ws

Documents

Emergency Ventilatory Management of the Critically Ill ...doctorfowler.com/www/lectures/emstoday2005ventilation.pdf · Rate: 6 breaths x min-1 (2 nd measurement ) one respiratory