Challenges In

Obstetric

Anesthesia

Elizabeth Wong, CRNA, MSN

LEARNING OBJECTIVES

To list the current challenges that CRNAs face

when delivering anesthesia to parturients

To describe methods that enhance the ability of

CRNAs to provide anesthesia to parturients safely

To review your current obstetric practice and

decide which of these methods can enhance your

current practice

domain free image at www.bing.com

Statistics Epidural and Spinal use during Labor:

United States birth statistics analyzed in 2009

4,130,665 births 1,686,213 parturients requested

epidural, spinal, or combined CSE

1,353,572 parturients had a c-section

(most common surgical procedure in

U.S.) www.cdc.gov

Maternal Mortality Statistics

www.cdc.gov

Maternal Hypertension 15%

Anesthesia Closed Claim Analysis

Since closed claim analysis began in 1984 8954 claims

Close Claim Analysis: Metzner et al. 2011 Best Practice and Research Clinical Anesthesiology.

Anesthesia Closed Claim

Analysis

Obstetric Anesthesia Closed Claim Analysis

1990-2003

426 total (58% c-section

and 42% vaginal delivery)

Liability associated with obstetric anesthesia. 2009. Davies et al. Anesthesiology.

Regional Anesthesia involved in 80% of claims while general

anesthesia involved in 17% of claims

Preventable cause: delay in anesthesia care, poor communication

Closed Claim Analysis - AANA

Reviewed cases from 1989 - 1999 and published in 2001

MacRae, M. D., Closed Claim Studies in Anesthesia: A literature review and implications for practice. AANA Journal. 2007.

Obstetric claims 19% - Death - 12%

AANA Position Statement

Position Statement Number 2.6 Administration of

Regional Anesthesia by Certified Registered Nurse

Anesthetists

Updated by the AANA Board 2010

www.aana.com

Challenge #1 - CMS RULE

The administration of medication via an epidural or

spinal route for the purpose of analgesia, during labor

and delivery, is not considered anesthesia and therefore

is not subject to the anesthesia supervision requirements

at 42 CFR 482.52(a).

However, if the obstetrician or other qualified physician

attending to the patient determines that an

operative delivery (i.e., C-section) of the infant is

necessary, it is likely that the subsequent administration

of medication is for anesthesia, as defined above, and the

anesthesia supervision requirements at 42 CFR

482.52(a) would apply."

#2 - Sleep Deprivation

Try performing delicate work without adequate rest!!!

24 hour shifts and busy labor units

24 hour shifts with call from home

24 hour shifts with in-house call

24 hour shifts are the culprit of sleep deprivation

Sleep Deprivation

Effect of work hour reduction on residents live: A

systematic review. Fletcher et al. JAMA. 2005

Sleep deprivation: Implications for Obstetric practice in the

United States. Clark. Am. Journal of Obstetrics and

Gynecology. 2009.

The effect of sleep deprivation on fine motor coordination

in ob/gyn residents. Avalon. et al. Am Journal of Obstetrics

and Gynecology. 2008.

Deconstructing and reconstructing cognitive performance

in sleep deprivation. Sleep medicine review. 2012.

What to do?

Get a good nights sleep before your 24 hour shift

If awakened in middle of the night:

Exercise - if possible. Use the stairwell and go up 1-2 flights,

do some jumping jacks...

Minimize the coffee intake. Drink water.

Do a legs up the wall inversion pose - if possible

Limit # of 24 hour shifts or try to split the shift

Have a 2nd provider on-call when work load excessive

You must have 3 nights of normal sleep to recover

image:: www.stessily.hubpages.com

#3- Loss of resistance: AIR SALINE HANGING DROP PLASTIC vs GLASS SYRINGES

Identification of the epidural space:

Air - 26% - improved LOR end point

Saline - ~ 73% improved LOR end point, fewer dural

punctures, fewer patchy blocks, less PDPH

No difference in pain relief - both deemed equally safe

Hanging drop - 1%

Epidural space identification: a meta-analysis for complications after air versus liquid as the medium for loss of resistance. Schier et al.

2009. International Anesthesia Research Society.

Labor epidural anesthetics comparing loss of resistance with air versus saline: Does the choice matter. Norman et al. 2006 AANA Journal

image:refdag.nl.comt

LOR...

Plastic syringes - smoother bounce, greater ability to

feel loss of resistance, lighter in the hand, does not

break when dropped

Glass syringes - gravel type feeling unless barrel of

syringe is washed with saline, heavy in hand, breaks

when dropped

No literature addressing safety etc.

image: www.bd.com

#4- C-section and the Failed Epidural - Causes

Incorrect primary placement

Secondary migration of catheter after correct placement

Suboptimal dosing of local anesthetic drugs (caveat - be

careful to discern the difference between difficult labor and

request for top-ups -unknown breech presentation - and

failed epidural)

Patient positioning

Use of median versus paramedian approach

Method used for catheter fixation - over shoulder or lateral

Obesity and large fat rolls with skin movement = catheter

migration

Failed Epidural: Causes and Management, J. Hermanides; M. W. Hollmann; M. F. Stevens; P. Lirk, British Journal of Anesthesia, 2012.

Failed Epidural - Management

Increase volume of local anesthetic

Increase concentration of local anesthetic

Add narcotics or epinephrine

Use a PCEA

Position patient in upright position so that sacral

nerves are anesthetized via gravity

If in O. R. either place single shot spinal with 1/2

regular dose or induce general anesthesia.

Failed epidural top-up for cesarean delivery for failure to progress in labor: the plan is to do a single shot spinal. Carvalho. International journal of obstetric anesthesia. 2011.

#5 - Local Anesthetic Toxicity

S & S may not appear for

~30 min

Vigilance is crucial

Standard resuscitative measures

20% Lipid emulsion of 1.5 ml/kg bolus followed by

continuous infusion of 0.25 ml/kg/min for 30-60 min.

The bolus can be repeated 1-2 times if patient is in

asystole

Varela, H & Burns, S. Use of LIpid emulsions for treatment of local anesthetic toxicity: A case report. AANA Journal. 2010

image: www.dailymed.com

#6 - Post-Dural Puncture Headache (syndrome)

First description of PDPH is 100 years ago by Bier

Factors include age, gender, pregnancy, needle type,

needle size, bevel direction, position, needle

orientation to dural fibers, number of attempts

S & S include photophobia, nausea, vomiting, neck

stiffness, tinnitus, diplopia, dizziness, cephalgia

(throbbing, frontal in origin).

Kuczkowski, KM. Post-dural puncture heardache in the obstetric patient: an old problem. New solutions. Minerva Anesthesiology. 2004.

Differential

Nonspecific headache

Caffeine-withdrawal headache

Migraine

Meningitis

Sinus Headache

Pre-eclampsia

Drug withdrawal (amphetamines, cocaine)

Pneumocephalus-related headache

Intracrainial pathology (hemorrhage, venous thrombosis)

Treatment

Theophylline

Caffeine (PO or IV)

Sumatriptan

Epidural saline

Epidural dextran

Subarachnoid catheter - 1. give 10-20 ml saline before

pulling out subarachnoid catheter 2. run a IV saline

infusion at 10 ml/ hour and dc before going home

Epidural blood patch (10-20 ml)

image: www..thelaughingstork.com

#7 - Amniotic Fluid Embolism

AFE first described in 1941

Most catastrophic challenge in OB

Embolic or immunologic in nature?

Resuscitative measures with Factor VIIa, ventricular

assist device, inhaled nitric oxide, cardiopulmonary

bypass, intraaortic balloon pump, extracorporeal

membrane oxygenation

Gist, RS., Stafford, MD., Leibowitz, MD & Bellin Y. Amniotic Fluid Embolism. Anesthesia & Analgesia. 2009.

#8 - Bleeding Disorders

Hemophilia

von Willebrands disease

Idiopathic thrombocytopenic purpura

Anticoagulated patients

Choi, S., Brull, R., Neuraxial Techniques in Obstetric and Non-obstetric Patients with Common Bleeding Disorders. Regional Anesthesia. 2009.

Green, L., Machin SJ. Managing anticoagulated patients during neuraxial aneesthesia. British Journal of Haematology. 2010.

image:.www.haemophelia.org.nz

Coagulopathic - Risks

Platelet count of 80k is safe for placing epidural

Platelet count of 40K is safe for placing spinal

Lower platelet counts may be safe but insufficient data exist

Use provider judgment at lower levels

If common bleeding diatheses - replace factors prior to block

performance

Tread carefully as there is a paucity of information in the literature

vsn Veen et al. The risk of spinal haematoma following neuraxial anaesthesia or lumbar puncture in thrombocytopenic individuals. British Journal of Haematology. 2009.

Choi, S. Neuraxial techniques in obstetric and nonobstetric patients with common bleeding diatheses. Regional Anesthesia. 2009.

Green et al. Managing anticoagulated patients during neuraxial aneaesthesia. British Journal of Haematology. 2010

#9 - Hemorrhage

Uterine Rupture

Vaginal birth after c-section

Repeat c-section

Placenta previa, accreta, or percreta

Coagulopaties

Hepner, DL., Gutsche, BB. Obstetric Hemmorrhage. Current Reviews for Nurse Anesthetists. 1998.

Ridgeway, J., Weyrich DL., Benedetti, TJ. Fetal Heart rate changes associated with uterine rupture. American College of Obtetricians and Gynecolotgists. 2004.

image:www.najms.org

California

California Maternal Quality Care

Collaborative (www.cmqcc.org)

California - ~550,000 annual births -

largest number of births in the nation

OB Hemorrhage Toolkit

#10 - Difficult Epidural or Spinal Placement

Low Spinal (0.5-1 ml marcaine 0.75%,

25 mcg fentanyl sit upright for 3 min) in

lateral position or moving patient and

return later to place epidural when

patient is more calm

Ultrasound (use OB ultrasound) vs blind

placement Carvalho, JCA. Ultrasound-facilitated epidurals and spinals in obstetrics. Anesthesiology Clinics. 2007.

Broadbent, CR., Maxwell, WB., Ferrie R., Wilson DJ., Gawne-Cain & Russell, R. Ability of anaesthetists to identify a marked lumbar interspace. Anaesthesia. 2000

Kline, JP. Ultrasound Guidance in Anesthesia. AANA Journal. 2011.

image:www.sciencephotobibrary.com

image:www.pie.med.utoronot.ca

#11 - DIFFICULT AIRWAY

Bottomline - assume every parturient

is a difficult intubation

The maternal airway may change

during labor. An assessment at the

beginning of labor may not be reliable

when confronted with an emergency c-

section.

Avoid general anesthesia if possible in

the obstetric population.

Follow the difficult airway algorithm

LMA, retrograde, lightwand, fiberoptic.

Just have a video assisted laryngoscope in the obstetric

operating room - best advice.

Questions?

Thanks to Karyn Karp, Mary Davis, Joe Janakes, Vera Hajduk.