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93
Critical Care Obstetrics, 5th edition. Edited by M. Belfort, G. Saade,
M. Foley, J. Phelan and G. Dildy. © 2010 Blackwell Publishing Ltd.
7
Cardiopulmonary Resuscitation in Pregnancy
Andrea Shields
1
& M. Bardett Fausett
2


1

Antenatal Diagnostic Center, San Antonio Military Medical Center, Lackland Airforce Base, Texas, USA

2
Obstetrics and Maternal - Fetal Medicine, San Antonio Military Medical Center and Department of Obstetrics and Gynecology,
Wilford Hall Medical Center, Lackland Airforce Base, Texas, USA
Introduction
Sudden cardiac arrest (SCA) is a leading cause of death in the
United States and Canada. An estimated 330 000 people die annu-
ally in the United States from SCA in out - of - hospital and emer-
gency department settings [1] . This translates to 0.55 per thousand
people in the US, and 1 in 30 000 gravid women who will suffer
SCA each year. Overall maternal mortality is signifi cantly higher
in developing countries including mortality from SCA. Women
of childbearing age are commonly healthy and the overall risk of
death is low in developed nations. These facts, along with the
additional life involved, make SCA in pregnancy unexpected and
particularly devastating.
Women are most likely to survive cardiopulmonary arrest
when attended by providers skilled in basic and advanced cardio-
pulmonary resuscitative techniques. The mechanical and physi-
ologic changes of pregnancy impact every phase of the resuscitation
process. In this chapter, we review the most recent American
Heart Association (AHA) cardiopulmonary resuscitation (CPR)
guidelines and emphasize pregnancy - specifi c modifi cations. We
do not address infant and child resuscitation in this chapter but
the practicing obstetrician should likewise be expert with neona-
tal resuscitation. In this chapter, we will consider other relevant
pregnancy - related issues such as perimortem cesarean section
and the ethical dilemma of prolonged maternal life support for
fetal maturation.

The initial objective of CPR and emergency cardiac care (ECC)
is to maintain adequate oxygenation and vital organ perfusion.
CPR restores hemodynamic stability in 40 – 60% of arrested
patients; however, prolonged survival is lower with underlying
illness [2] . Overall outcome, particularly full neurologic recovery,
is improved by early initiation of CPR and defi brillation. Most
victims of SCA demonstrate ventricular fi brillation at some point
leading to full arrest. Ventricular fi brillation is best treated by
electrical cardioversion performed within the fi rst 5 minutes after
collapse [3] . Since the majority of SCA occurs outside of the
hospital setting, it is uncommon for emergency medical service
personnel to be contacted and arrive at the victim ’ s side within
these critical 5 minutes [4] . Thus, achieving a high survival rate
depends upon public training in CPR and well - organized public
access defi brillation programs. Considering all victims, out - of -
hospital survival rates for SCA victims are only 6% but can
improve to 75% when victims are given high - quality CPR [4] .
Outside of the hospital, SCA is usually associated with cata-
strophic trauma and is rarely a survivable event for pregnant
women even in developed countries.
In the hospital, SCA in pregnancy is usually associated with
peripartum events [5] . In such circumstances delivery of
high - quality CPR is likely to have a signifi cant impact on survival
rates. Thus, hospital personnel involved in the care of pregnant
women should be expertly trained and facile in techniques of
cardiopulmonary resuscitation. Obstetrical units should have
proper resuscitative equipment readily available and staff
members be engaged in ongoing programs to train and maintain
CPR competency. In one recent evaluation of obstetric training
programs, the authors concluded that even basic life support

knowledge and skills are inadequate and ongoing training is
necessary [6] .
Current c ardiac c are r ecommendations
In December 2005, the American Heart Association published an
update to the guidelines for lay and professional Basic and
Advanced Cardiac Life Support (BLS/ACLS). A summary of the
ABCDs of lay and provider rescuer BLS is shown in Table 7.1 .
The primary changes to the 2005 resuscitation guidelines were
meant to simplify algorithms and promote their early application
to SCA victims. The new guidelines include four major changes
relevant to women of reproductive age and are applicable to both
lay and provider rescuer CPR [7] . These general changes are sum-
marized in Table 7.2 .
Chapter 7
94
Airway Head tilt/chin lift unless trauma then use jaw thrust
Breathing : Initial 2 breaths at 1 second/breath
Rescue breathing without chest compressions 10 – 12 breaths/min
Rescue breaths with advanced airway 8 – 10 breaths/min
Foreign body obstruction Abdominal thrusts
Circulation
Pulse check ( ≤ 10 s)
Carotid
Compression landmarks Lower half of sternum, between nipples
Compression method Heel of one hand with the other on top; push hard and fast
and allow complete recoil
Compression depth 1 ½ to 2 inches
Compression rate 100/min
Compression : ventilation ratio 30 : 2 (either one or two rescuers)
Defi brillation

AED After 5 cycles of CPR if out of hospital
Table 7.1 Summary of CPR ABCD s (modifi ed from
“ Summary of BLS ABCD maneuvers for infants,
children and adults ” ) [68] .
Table 7.2 Summary of key changes in 2005 CPR guidelines [4] .
Deliver more effective chest
compressions
Early, consistent, fast, hard
Single compression : ventilation
ratio for all but neonates
30 : 2
Rescue breaths Given over 1 second; 500 – 600 mL for adults
Defi brillation After fi rst shock go directly to
compression : ventilations × 2 min
First, there is signifi cant emphasis on, and recommendations
to improve, delivery of effective chest compressions. The key
words are early, consistent, fast and hard. This emphasis is made
because half of chest compressions (even by healthcare providers)
are too shallow. The chest is often not allowed to recoil ade-
quately between compressions and interruptions are too common.
Complete chest wall recoil increases cardiac fi lling by increasing
negative pressure, promoting venous return and maximizing
cardiac output with the subsequent compression. The fi rst few
compressions after interruption are not as effective as those that
follow. Thus, inadequate compressions, incomplete chest recoil
and frequent interruptions all signifi cantly decrease circulation
and oxygen delivery and decrease survival [7] .
The second new recommendation is for a single 30 : 2 compres-
sion to ventilation ratio for all victims except newborns. The
guideline authors note most cases of cardiac arrest in adults are

not hypoxia - induced. Consequently, circulation is more critical
than ventilation in the fi rst minute of CPR. Since the blood fl ow
to the lungs is diminished (25 – 33%) during arrest/CPR, victims
need less ventilation than normal. In contrast, newborn cardiac
arrest is commonly related to hypoxia so more ventilations (5:1)
to compressions are indicated and remain part of the new guide-
lines [7] .
The third recommendation is that each rescue breath should
be given over 1 second (rather than 1 – 2 seconds) and produces
a visible chest rise. The visible chest rise ensures effi cacy and the
1 - second breath provides adequate tidal volume (500 – 600 mL)
while avoiding hyperinfl ation. Rescuers are to take a normal
breath before giving the rescue breath. Frequent rescue breathing
interrupts and delays chest compressions. Hyperinfl ation
increases intrathoracic pressure leading to decreased blood return
to the chest. This results in diminished effi cacy of the next several
compressions and increases the risk of gastric insuffl ation.
The fi nal new major recommendation is that during ventricu-
lar fi brillation (VF) cardiac arrest, a single shock should be given
followed by immediate CPR. CPR is to begin even before the fi rst
rhythm check 2 minutes later. Historically, rhythm analysis by
automated defi brillators available before 2005 resulted in delays
of more than 30 seconds before giving the fi rst post - shock com-
pressions. Current defi brillators eliminate VF more than 85% of
the time. Thus, in a case where the fi rst shock fails, CPR is likely
to convey greater value than a second shock. Even when a shock
eliminates VF, it usually takes several minutes for a normal effec-
tive rhythm to return. A brief period of CPR can increase energy
and oxygen to the heart, increasing the likelihood that the heart
will be able to continue effective blood fl ow. There is no evidence

that postdefi brillation chest compressions provoke recurrent VF.
For similar reasons, lay rescuer CPR recommendations now
eliminate the initial check for pulse after giving the initial two
rescue breaths [7] .
Key changes to recommendations for provider - level and hos-
pital - based adult BLS include use of the 30 : 2 ventilation to com-
pression ratio (even with two rescuers) until an advanced airway
is in place. As noted in the general guidelines above, before an
advanced airway is in place, rescuers should perform 5 cycles of
CPR after shock before the next rhythm check. Even once the
advanced airway is in place, rescuers should perform 2 minutes
Cardiopulmonary Resuscitation in Pregnancy
95
of CPR after shock before the next rhythm check. With two
or more rescuers and an advanced airway in place, rescuers
no longer provide cycles of compressions with pauses for ventila-
tion. One rescuer provides 8 – 10 breaths per minute (1 every 6 – 8
seconds) while the other rescuer provides continuous compres-
sions. Where possible, rescuers should rotate the compressor role
every 2 minutes, taking no more than 5 seconds to do so. After
2 – 3 minutes of CPR, rescuers typically perform chest compres-
sions less effectively [7] . The general provider BLS algorithm is
shown in Figure 7.1 and the pulseless arrest ACLS algorithm in
Figure 7.2 . Algorithms for tachycardia and bradycardia are not
included here but are usually available on all “ code carts ” .
Patient p opulation and e tiologies of SCA
in p regnancy
Of women who suffer SCA during pregnancy, most have throm-
boembolic - , followed by hemorrhage - , related events [8] . The
most common causes of SCA during pregnancy are listed in Table

7.3 . Victims of SCA in pregnancy are younger and have fewer
underlying medical conditions than non - pregnant victims [8] .
However, maternal age and underlying medical problems con-
tinue to increase in developed countries due to elective delayed
childbearing and advanced reproductive technologies.
Pregnancy increases the risk of venous thromboembolic disease
(VTE) due to hormonally stimulated increases of virtually all of
the procoagulant proteins. The risk of VTE is amplifi ed by condi-
tions necessitating bed rest such as gestational hypertensive dis-
orders and preterm labor. The risk is highest in the immediate
postpartum period, [9] probably due to the tissue trauma and
decreased physical activity associated with delivery.
Lipo - oxidative injury to the coronary vessels is the most
common cause of SCA in non - pregnant individuals but is an
uncommon cause of SCA in pregnancy. However, the added
physiologic stress of pregnancy can unveil underlying congenital
or acquired valve disease. Pregnancy does increase the risk of
myocardial infarction 3 – 4 - fold over otherwise comparable non -
pregnant women. The pregnancy - related MI risk is signifi cantly
greater in women older than 30 years [10] . Additionally, pregnant
women have a relatively increased risk of coronary artery and
aortic dissections compared to non - pregnant women with other-
wise similar demographic characteristics [11] . This may be due
to progesterone - mediated relaxation of smooth muscle.
Pregnancy - s pecifi c c onditions a ssociated
with SCA
Turning now to pregnancy - specifi c conditions associated with
SCA, we fi rst highlight the anaphylactoid syndrome of pregnancy
also called amniotic fl uid embolus (AFE). This disorder is char-
acterized by an anaphylaxis - like syndrome that is associated with

cardiac depression, cardiopulmonary collapse and coagulopathy.
The disorder is highly lethal with a 50 – 65% risk of cardiac arrest
and maternal death [12 – 15] . This catastrophic condition is
discussed in detail in Chapter 35 but the reader is encouraged
to remember that this disorder is associated with profound
vascular leak, and over - resuscitation with crystalloid fl uids can
result in massive pulmonary edema. Therapy targeted to support
the cardiovascular system and correct the coagulopathy while
avoiding over - resuscitation with crystalloid fl uid may be helpful
[16] .
Gestational hypertensive disorders occur more frequently than
thromboembolic disorders and both occur more commonly than
anaphylactoid syndrome of pregnancy [14] . Women with hyper-
tensive disorders of pregnancy are at increased risk of SCA for
several reasons including the associated underlying endothelial
injury and infl ammatory response. Hypertension may necessitate
medical therapy and magnesium is often used for seizure prophy-
laxis. Both may be associated with cardiac compromise leading
to SCA [17 – 20] . Profound hypotension and SCA can occur in
women with pre - eclampsia treated concurrently with calcium
channel antagonists and magnesium sulfate. In cases of cardio-
pulmonary compromise due to magnesium sulfate toxicity,
resuscitation must include calcium rescue. The typical dose is 1 g
of intravenous calcium carbonate.
ABCD s in p regnancy
If breathing stops fi rst, then the heart often continues to pump
for several minutes usually providing enough oxygen in the lungs
and bloodstream to support life for up to 6 minutes [21] . In
contrast, when the heart stops fi rst, oxygen in the lungs and
bloodstream cannot be circulated to vital organs. The patient

whose heart and respirations have stopped for less than 4 minutes
has an excellent chance of recovery if CPR is administered imme-
diately and is followed by ACLS within 4 minutes [22] . By 4 – 6
minutes, brain damage may occur, and after 6 minutes, brain
damage will almost always occur. Therefore, the initial goals of
CPR are to deliver oxygen to the lungs and provide a means of
circulation to the vital organs. Initially circulation is provided via
closed - chest compression followed by ACLS, with restoration of
the heart as the mechanism of circulation. These goals are
achieved by remembering the “ ABCDs ” of the primary and sec-
ondary survey (Table 7.1 ). The primary survey consists of airway
management using non - invasive techniques, breathing with pos-
itive - pressure ventilations, and performing CPR until equipment
for external defi brillation arrives. Out - of - hospital and BLS tools
required include gloved hands, a barrier device for CPR, and an
automated external defi brillator (AED) for defi brillation. A sec-
ondary survey requires the use of advanced, invasive techniques
as the rescuer attempts to resuscitate, stabilize, and transfer the
patient to a higher level of care if indicated (i.e. hospital or inten-
sive care setting). Potentially reversible causes of cardiopulmo-
nary arrest should also be considered and addressed at this stage
(Table 7.4 ).
Chapter 7
96
If not breathing, give 2 BREATHS that make chest rise
Denite
Pulse
Shockable Not Shockable
If no response, check pulse:
Do you DEFINITELY feel

pulse within 10 seconds?
No movement or response
PHONE 911 or emergency number
Get AED
or send second rescuer (if available) to do this
Open AIR WAY, check BREATHING
Resume CPR immediately
for 5 cycles
Check rhythm every
5 cycles; continue until ALS providers
take over or victim starts to move
Give cycles of 30 COMPRESSIONS and 2 BREATHS
until AED/debrillator arrives, ALS providers take over, or
victim starts to move
Push hard and fast (100/min) and release completely
Minimize interruptions in compressions
AED/debrillator ARRIVES
Check Rhythm
Shockable rhythm?
Give 1 shock
Resume CPR immediately
for 5 cycles
-Give 1 breath every
5 to 6 seconds
-Recheck pulse every
2 minutes
5A
1
2
3

4
5
6
7
8
910
No Pulse
Figure 7.1 ACLS Adult BLS Provider Algorithm. Modifi ed from Circulation 2005; 112: IV - 58 – IV - 66.
Cardiopulmonary Resuscitation in Pregnancy
97
Figure 7.2 ACLS Adult Pulseless Arrest Algorithm. Modifi ed from Circulation 2005; 112: IV - 58 – IV - 66.
Shockable Not Shockable
Shockable
Give 5 cycles of CPR*
Give 5 cycles of CPR*
Shockable
Give 5 cycles of CPR*
Not Shockable Shockable
Check rhythm
Shockable rhythm?
PULSELESS ARREST
• BLS Algorithm: Call for help, ve CPR
• Give oxygen when available
• Attach monitor/debrillator when available
Continue CPR while debrillator is charging
Give 1 shock
• Manual biphasic: device specic (typically 120 to 200 J)
• AED: device specic
• Monophasic: 360 J
Resume CPR immediately after the shock

When IV/IO available, give vasopressor during CPR (before
or after the shock)
• Epinephrine 1 mg IV/IO
Repeat every 3 to 5 minutes
or
• May give 1 dose of vasopressin 40 U IV/IO to replace
rst or second dose of ephinephrine
VF/VT
Asystole/PEA
Give 1 shock
• Manual biphasic: device specic
(typically 120 to 200 J)
• AED: device specic
• Monophasic: 360 J
Resume CPR immediately
Check rhythm
Shockable rhythm?
Continue CPR while debrillator is charging
Give 1 shock
• Manual biphasic: device specic (typically 120 to 200 J)
• AED: device specic
• Monophasic: 360 J
Resume CPR immediately after the shock
Consider antiarrhythmics; give during CPR
(before or after the shock)
amiodarone (300 mg IV/IO once, then
consider additional 150 mg IV/IO once) or
lidocaine (1 to 1.5 mg/kg rst dose, then 0.5 to 0.75 mg/
kg IV/IO, maximum 3 doses or 3 mg/kg)
Consider magnesium, loading dose 1 to 2 g IV/IO for

torsades de pointes
After 5 cycles of CPR,* go to Box 5 above
Check rhythm
Shockable rhythm?
• If asystole, go to Box 10
• If elecrical activity, check
pulse, If no pulse, got to
Box 10
• If pulse present, begin
postresuscitation care
Resume CPR immediately for 5 cycles
When IV/IO available, give vasopressor
• Epinephrine 1 mg IV/IO
Repeat every 3 to 5 minutes
or
• May give 1 dose of vasopressin 40 U IV/IO to
replace rst or second dose of ephinephrine
Consider atropine 1 mg IV/IO
for asystole or slow PEA rate
Repeat every 3 to 5 min (up to 3 doses)
Check rhythm
Shockable rhythm?
Go to
Box 4
During CPR
• Push hard and fast (100/min)
• Ensure full chest recoil
• Minimize interruptions in chest
compressions
• One cycle of CPR; 30 compressions

then 2 breaths; 5 cycles takes about
2 min
•Avoid hyperventilation
• Secure airway and conrm placement
After an advanced airway is placed,
rescuers no longer deliver “cycles”
of CPR, Give continuous chest com-
pressions with pauses for breaths.
Give 8 to 10 breaths/minute. Check
rhythm every 2 minutes
• Rotate compressors every 2 minutes
with rhythm checks
• Search for and treat possible
contributing factors:
•Hypovolemia
•Hypoxia
•Hydogen ion (acidosis)
•Hypo-/hyperkalemia
•Hypoglycemia
•Hypothermia
•Toxins
•Tamponade, cardiac
•Tension pneumothorax
•Thrombosis (coronary or
pulmonary)
•Trauma
No
No
1
2

3
4
5
6
7
8
9
10
11
12
13
Airway
Delivery of oxygen is achieved by positioning the patient,
opening the airway, and delivering rescue breaths. In the absence
of muscle tone, the tongue and epiglottis frequently obstruct the
airway. The head tilt with the chin - lift maneuver (Figure 7.3 ) or
the jaw thrust maneuver (Figure 7.4 ) facilitates airway access. If
foreign material appears in the mouth, it should be removed. If
air does not enter the lungs with rescue breathing, reposition the
head and repeat the attempt at rescue breathing. Persistent
obstruction may require the Heimlich maneuver (subdiaphrag-
matic abdominal thrusts), chest thrusts, removal of foreign body
if now visualized, and rescue breathing. The Heimlich maneuver
cannot be used in the late stages of pregnancy or in the obese
choking victim. Airway obstruction may occur in a choking
victim as well as the patient experiencing a cardiopulmonary
arrest. The conscious women with only partial airway obstruction
should be allowed to attempt to clear the obstruction herself.
Rescuers should avoid the fi nger sweep in a conscious patient.
In the fi rst half of pregnancy, airway obstruction can be relieved

with the Heimlich maneuver or abdominal thrusts. From a stand-
ing position the rescuer wraps his arms around the victim ’ s waist,
making a fi st with one hand and placing the thumb side of the
fi st against the victim ’ s abdomen in the midline slightly above
the umbilicus and well below the top of the xiphoid process. The
rescuer grasps the fi st with the other hand and presses the fi st into
the victim ’ s abdomen with quick, distinct, upward thrusts. The
thrusts are continued until the object is expelled or the victim is
unconscious. The unconscious victim is placed supine, the heel
of one hand remains against the victim ’ s abdomen, in the midline
slightly above the umbilicus but below the top of the xiphoid. The
Chapter 7
98
second hand lies directly on top of the fi rst, and quick upward
thrusts are administered.
In the latter half of pregnancy, the gravid uterus or maternal
habitus may necessitate the use of chest thrusts instead of abdom-
inal thrusts. Chest thrusts in a conscious sitting or standing victim
require placing the thumb side of the fi st on the middle of the
sternum, avoiding the xiphoid and the ribs. The rescuer then
grabs his or her own fi st with the other hand and performs chest
thrusts until either the foreign object is dislodged or the patient
loses consciousness. The unconscious patient is placed supine.
The rescuer ’ s hand closest to the patient ’ s head is placed 2 fi nger-
breadths above the xiphoid. The long axis of the heel of the
provider ’ s hand rests on the long axis of the sternum and the
other hand lies over the fi rst, with the fi ngers either extended or
interlaced. The elbows are extended and the chest is compressed
1.5 – 2 inches. Up to 5 abdominal or chest thrusts are given fol-
lowed by repetition of the jaw - lift, foreign body visualization, and

attempted ventilation. These steps are repeated until effective or
until a surgical airway can be obtained by emergency cricothy-
rotomy or jet - needle insuffl ation.
If, after clearing any obstruction, the patient is unresponsive
but breathing spontaneously, she is placed in the recovery posi-
tion to keep the airway open. The pregnant victim is placed on
her left side. The left arm is placed at a right angle to the victim ’ s
torso, while the right arm is placed across her chest with the back
of her hand under the lower cheek. The victim ’ s right thigh is
fl exed at a right angle to the torso, across the left leg, with the
right knee resting on the surface. The victim ’ s head is tilted back
to maintain the airway, using the right hand to maintain the head
tilt. Fetal monitoring should begin as soon as possible and breath-
ing is monitored regularly. If breathing does not resume after
clearing the airway or if it stops, the emergency medical system
is activated and the BCDs of CPR continued.
Table 7.3 Causes of cardiac arrest during pregnancy [69] .
Venous thromboembolism
Pregnancy - induced hypertension
Sepsis
Amniotic fl uid embolism
Hemorrhage
Placental abruption
Placenta previa
Uterine atony
Disseminated intravascular coagulation
Trauma
Iatrogenic
Medication errors or allergy
Anesthetic complications

Hypermagnesemia
Pre - existing heart disease
Congenital
Acquired
Table 7.4 Potentially reversible causes of cardiac arrest.
Hypovolemia
Hypoxia
Hydrogen ion acidosis
Hyper - or hypokalemia, other metabolic
Hypothermia
Tablets (drug overdose)
Trauma
Tamponade, cardiac
Tension pneumothorax
Thrombosis, coronary
Thrombosis, pulmonary
Toxins (e.g. amniotic fl uid)
Figure 7.3 Head tilt, chin lift.
Figure 7.4 Jaw thrust.