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1. Spencer Topp, MD
Department of Emergency Medicine
University of Florida-Jacksonville

2. It’s a quiet Tuesday morning in Resus and Laperouse is
peacefully sipping his coffee, updating his procedure log on
New Innovations while Al is busy restocking bed #4 and
bitching the whole time he’s doing it.
The EMS phone suddenly goes off and someone yells
out- “JFR has a 34-week pregnant lady in respiratory distress
and they’re requesting a resus bed!”

3. Upon arrival, you get a quick story from EMS that the lady is a 24-
year old G1P0 at about 34 weeks. She had acute onset of SOB and
chest pain and her husband called 911. She is in obvious
respiratory distress, diaphoretic, and not mentating
appropriately. She quickly gets hooked up to the monitor and
her vitals show-
BP- 85/40, Pulse 144, RR 34, O2 sats 92% Temp 98.7, Accu-check 112

4. Physical Exam
Gen- tachypnic, diaphoretic
HEENT-no trauma, PERRL, MMM, no JVD
Cardiac- tachycardic, loud systolic murmur over pulmonic
valve, no S3 or S4
Lungs- tachypnic, otherwise CTAB
Abdomen- consistent with a 34-week gestation, no obvious TTP
Ext- 1+ bilateral LE edema, weakly palpable peripheral pulses
Neuro- AOx 1 (person only), one word responses, follows
minimal commands, however moving all extremities
Fetus- doppler showed fetal cardiac activity- 150-160 BPM

5. -2 IV’s established, 2 L NS hanging, 100% NRB applied, and Life-Pak
pads placed
-Labs ordered and sent, EKG and CXR completed
-About 10 minutes after arrival, no significant change – what do you
want to do now?
-You’re quickly trying to remember if RSI is safe in pregnancy when
suddenly Al says, “guys, I don’t think she has a pulse anymore.”
-Rhythm on monitor shows PEA and color of Laperouse’s pants shows
brown.

6. -Discuss incidence and causes of maternal cardiac arrest during
pregnancy
-Discuss pregnancy related physiologic changes
-Differences in ACLS algorithms during pregnancy?
-What therapy options are available?
-What drugs are safe?
-Emerging therapies for maternal cardiac arrest?

7. -Incidence of cardiac arrest is about 1 in 30,000 pregnancies
-
Because most pregnant women are young and healthy, causes of arrest differ
slightly from the general population
-Causes include:
1) Pulmonary Embolism
2) Pre-ecclamsia/Ecclampsia
3) Sepsis
4)Maternal hemorrhage
-these account for nearly 70% of all maternal arrests
-amniotic fluid embolism, trauma, peripartum cardiomyopathy, stroke and MI
account for the remainder
-iatrogenic causes- hypermagnesmia, anaphylaxis, anesthesia complications

8. Airway Changes
 Upper airway edema and increased
secretions
 Most women go from Mallampati
class 1 or 2 to a grade 4 airway by term
 Progesterone delays gastric emptying,
increasing risk of aspiration
 Gravid uterus compresses diaphragm
making BVM more difficult
Airway Changes during Labor and Delivery
Kodali B-S, Chandrasekhar S, Bulich LN
Anesthesiology
vol. 108, 357 - 362, 2008

9. Pulmonary Physiology Changes
 Progesterone induced increase in minute ventilation through
increased tidal volume
-ABG’s during late pregnancy shows a compensated respiratory
alkalosis (PCO2 of 28-32)
 Decreased functional residual capacity and limited oxygen reserve
-pregnant patients quickly desaturate during both RSI (with proper
pre-oxygenation) or apnea caused by arrest
 Chest wall compliance is reduced secondary to mechanical effects
(enlarged breasts and gravid uterus)

10. Cardiovascular Physiologic Changes
 Increased cardiac output (30-50% by 32 weeks)
 Increased oxygen consumption
Decrease in SVR secondary to uteroplacental blood flow
-up to 30% of CO goes to pregnant uterus, compared to 2% in non-gravids
Aortocaval compression by the gravid uterus
- in the supine postion, venous blood return may be completely obstructed with all
blood return supplied by the azygous, lumbar and paraspinal veins

11. -In general, resuscitation algorithms during cardiac arrest are
the same for pregnant and non- pregnant patients (with a few
exceptions)
• more aggressive airway management
• slight modification in CPR/chest
compressions
• early consideration of perimortem
cesarean delivery

12. -Cardiac output during CPR is estimated to be ~30% of normal
-Uteroplacental blood flow is markedly reduced even with optimal
chest compressions
-During the second half of pregnancy, when performing CPR, an
attempt is made to relieve the aortocaval compression that occurs in
the supine position
-However, a true “lateral decubitus” position is not optimal when
performing chest compressions

13. Rees and Willis in 1990
-measured the force achieved with chest
compressions in the supine, lateral decub, and
various intermediary angles as compared to
optimal CO
-their work led to the development of the
Cardiff wedge
-inclined at 27o to specifically perform CPR
on pregnant patients
If no wedge available, rolled up bed
sheet under patient’s right hip or
knee of resus team member under
patient’s right hip
Also can try manual displacement
of uterus up and to the left (much like
pannus retraction during central line placement)

14. No changes in defibrillator pad
placement in pregnancy
No changes in defibrillator energy
requirements
 Nanson et al studied transthoracic
impedence
 looked at 45 women at term and then
again at 6-8 weeks post-partum
 no difference in the two groups
No contraindication to external
defibrillation in pregnancy
 multiple studies have demonstrated
no adverse fetal effects
 countershocks up to 400 J have been
used without adverse fetal effects

15. ACLS medications are given in the standard
doses and routes
Theoretically, the α-adrenergic agents may
cause uteroplacental vasoconstriction
 This further compromises already poor uterine
blood supply
 However, actual clinical effects not known (try
posing that one to the IRB)
Sodium Bicarb use controversial
 May worsen fetal acidosis
The BEST chance for fetal survival is rapid
resuscitation of the mother

16. Symptomatic bradycardia rare occurrence
during pregnancy
Common causes include:
 Vasovagal events
 Hypothyroidism
 Hypothermia
 Myocardial ischemia
 Supine Hypotensive Syndrome of Pregnancy
(bradycardia, hypotension, syncope)
Treatment for symptomatic pregnant
patients no different
 Atropine still treatment medication of choice
 Transcutaneous pacing also safe during
pregnancy

17. Most frequent tachyarrhythmia of
pregnancy
Pregnancy increases risk for new onset
SVT
Pregnancy also increases frequency
and severity of pre-existing SVT
Treatment algorithm same as for non-
gravids
 Stable vs unstable
 Again, DC cardioversion safe
 Adenosine at standard doses also safe

18. In setting of structurally normal hearts, VT in pregnancy is rare
When VT does occur in pregnant patient consider these causes:
 Severe acid-base disorder
 Severe electrolyte disorder
 Abuse of stimulants
Again, cardioversion and defibrillation safe
Lidocaine (class B) and Procainamide (class C) safe for sustained, stable VT
Amiodarone (class D)- use limited by teratogenic profile
 Use for pharmacologic and shock resistant VT

19. As discussed previously, ACLS algorithms basically unchanged
Remember left lateral decub position for chest compressions
Intubate sooner than during other code situations
Defibrillate at same energies
Epinephrine, Vasopressin, Atropine should not be withheld
because of concern for fetal effects
How long do you resuscitate the mother before you turn your
attention to a viable fetus?

20. Cesarean delivery is one of the
oldest surgical procedures, dating
back nearly 3000 years
The procedure is believed to have
derived it’s name from the Lex Cesare
or “Law of Caesar”
 Fetuses had to be separated from the
mothers who died during child birth
for religious purposes
 Interestingly, some of the infants
survived
Perimortem C-section first began to
be described in the medical literature
in the late 19th and early 20th centuries

21. Katz and colleagues in 1986 reviewed all the reports of
perimortem C-sections
 Found reports of 188 such precedures
 61 of the reports included time of arrest or death of the mother to time
of delivery of infant
Time (in minutes) # of infants
surviving
% surviving neuro
intact
0-5 45 98
6-15 18 83
16-25 9 33
26-35 4 25
36+ 1 0

22. Based on these findings, Katz and colleagues recommended
 “initiation of C-section within 4 minutes of maternal arrest and fetal
delivery within 5 minutes.”
These recs have been supported by other studies and
consensus panels
Forms the basis of the “4 minute” rule
Case reports of prolonged time (>20) do not make this “4
minute rule “ absolute

23. Gestational age is an important factor in predicting the prognosis
for infants after perimortem cesarean deliveries
What is the gestational age threshold for expected fetal viability?
-Most institutions agree between 24-26 weeks
Because exact gestational age is sometimes unknown during an
arrest situation, what are some ways you can estimate GA?
-Ultrasound (also gives info on fetal lie, placental location, or presence of
fetal cardiac activity)
-Measure from pubic symphysis to top of uterine fundus

24. The primary goal of perimortem C-section traditionally has
been to save the fetus
The procedure may be life saving for both mother and fetus
 Significant aortocaval compression by >20 week uterus
 Delivery of fetus may significantly improve maternal cardiac output
 Numerous case reports to support this (?)
Cardiac arrest in early pregnancy
 Unknown if C-section is beneficial
 Much smaller fetal-placental mass, little to no aortocaval compression
 Less hemodynamic benefits
 Not recommended at gestational age of less than 24 weeks
 Focus on optimizing resuscitation of mother

25. Prepare for emergent c-section as soon as cardiac arrest identified in
the pregnant woman
Quickly determine gestational age during initial resuscitation of
mother
Once procedure begins, ideally two teams now working
independently
 CPR is continued on mother
Factors that increase the infant’s chance of survival
 Short interval between arrest and delivery
 No sustained prearrest hypoxia of mother
 Minimal or no signs of fetal distress before arrest
 Aggressive/effective resuscitation of mother
 Procedure performed in center with neonatal ICU
 Emergency C-section within rescuer’s procedural range of experience/skills

26. No randomized controlled trials about thrombolytics in
pregnancy have been conducted
pregnant women were excluded from phase-II and phase-III
trials for Alteplase (t-PA)
The package insert for t-PA states pregnancy to be a “relative
contraindication,” with other sources stating t-PA to be
pregnancy category B (presumably safe based on animal
studies)
Thrombolytics do not cross the placenta

27. In 2006, Leonhardt et al. published a review article dealing with the
question of thrombolytic safety during pregnancy
28 cases in which t-PA had been used during pregnancy
Indications for use were stroke (n=10), thrombosis of cardiac valve
prosthesis (n=7), pulmonary embolism (n=7), DVT (n=3), and myocardial
infarction (n=1)
The pregnant patients that received thrombolytics did not have any
higher complication rates than in the large, randomized trials for
thrombolytics in stroke, PE, or MI
6 of the children (24%) died, 3 secondary to abortion for maternal
health. In only 2 of the fetal deaths was there a probable, causal
relationship between fetal death and the use of t-PA (8%).

28. Alternatives to thrombolytics in massive PE would be surgical embolectomy or
catheter-directed thrombolytic therapy
not always available in a time-sensitive fashion, and not without their own risks
and complications (10% fetal death reported during surgical embolectomy)
Unfortunately, not enough good evidence exists to propose a set of guidelines for
the use of thrombolytics in a pregnant patient
small series of case reports available suggests the use of thrombolytics to be both
safe and efficacious in the treatment of massive PE in pregnancy
should be considered on a case by case basis, keeping in mind it may be the
quickest, most efficacious treatment
Keep in mind, would definitely complicate an emergent C-section

29. Single case report of a 35 y/o, 13 weeks pregnant
Witnessed, out-of-hospital V-fib arrest
Defibrillated 4 times and Lidocaine given for non-sustained, polymorphic VT
Decision was made, in consult with family, for therapeutic hypothermia for 24 hours
At goal of 33oC, fetal bradycardia (90-100 BPM) was noted
Pt rewarmed and fetal HR normalized
Mother sustained mild neurologic deficits
Infant was “normal” at 2 months