Cardiac Arrest in the Obstetric Suite

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Cardiac Arrest in the Obstetric Suite
Sheila E. Cohen MB.Ch.B Stanford
University Stanford, California
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Case Summary 1
2 a.m.

• A 40 year old woman, 37 weeks pregnant with TWINS
  arrives at the hospital
• Cervix 6 cm dilated. Patient is in severe pain.
  Labor is progressing rapidly
• Epidural block 15 ml 0.125 bupivacaine
  fentanyl 75 µg
• 15 minutes later - patient is still in severe
  pain
• 12 ml 0.25 bupivacaine given in two increments
• Patient is comfortable. You go to bed and fall
  into a deep sleep...

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Case Summary 2
3 a.m.

• Obstetrician and anesthesiologist called stat
  to labor room
• Membranes ruptured spontaneously 10 min ago
• 3 min ago, the patient complained of difficulty
  breathing and lost consciousness
• Fetal heart rate 90 beats/min
• Vaginal bleeding
• Patient cyanotic
• Maternal BP and Pulse not obtainable

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Case Summary 3
3.03 a.m.

• Patient mask ventilated with Ambu bag and O2
• No improvement
• Cardiac arrest team called stat
• You start CPR with the aid of the nurse

3.07 a.m.

• Code team arrives - starts Advanced Cardiac Life
  Support (ACLS)
• Patient is intubated - she aspirates gastric
  contents!
• ASYSTOLE diagnosed

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Case Summary 4
3.10 a.m.

• All IV lines displaced during CPR
• Epinephrine given via endotracheal tube
• IVs replaced with difficulty

3.13 a.m.

• No maternal Pulse or BP detected
• FHR 50-60 beats/min
• Cervix 8 cm dilated

3.17 a.m.

• Patient transported to OR while closed chest
  massage (CPR) continues
• Cesarean Section started

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Case Summary 5
3.23 a.m.

• Delivery of male infants
• A Apgar 0, 1, 4 (at 1, 5, and 10 minutes)
• B Apgar 0, 0, 0

Delivery occurred 23 minutes after start of CPR
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Case Summary 6
3.25 a.m.

• Maternal heart rate returns

3.30 a.m.

• BP 100/70 Pulse 130
• Significant bleeding

22.00 p.m.

• Mother unconscious in ICU
• Coagulopathy (DIC) resolving

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Possible Causes of Cardiac Arrest

• Amniotic fluid embolism
• Pulmonary embolism
• Hemorrhage (including ruptured uterus)
• Myocardial infarction, cardiomyopathy
• High spinal (or sub-dural) anesthesia
• Spinal opioid respiratory depression
• Drug overdose or toxicity

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Lets Do an Elective C/Section

• Healthy 30 y old primigravida with twins for
  elective C/S (breech/Vx)
• 5 ft 4 inches tall, 70 kg
• Patient is active runs 5 miles x 3 each week
• Pre-operative BP 98/60 Pulse 52
• Fluid preload - 1500 ml crystalloid solution
• Uncomplicated spinal at L3/4, patient sitting
• Bupivacaine 12 mg Fentanyl 10 µg Morphine
  0.2 mg

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Continued

• Patient is placed supine, left uterine
  displacement
• Block T4 bilaterally (3 min after spinal)
• I dont feel well My hands are numb
• I cant breathe.
• Poor hand strength - patient cannot raise arm
• Patient is anxious, diaphoretic, nauseated

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Events after Spinal Block for Cesarean Section
Hands numb Nausea
Cardiac Arrest!
Ephedrine (mg)
Phenylephrine 100 µg
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10
10
5
5
10
10
10
Time after spinal block (min)
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Cardiac Arrest during Spinal for Cesarean Section

• Code team called trachea intubated
• CPR / ACLS started
• Immediate Cesarean Section performed
• Delivery 5 min after arrest occurred
• Apgar scores
• A 5, 6, 7
• B 3, 4, 5
• Babies to Intensive Care severely acidotic

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Post-Delivery Course

• Mother responds to epinephrine 1 mg x 3 after 10
  minutes of resuscitation (5 min after delivery)
• BP 160/110, P 140
• To ICU, intubated
• Mother has residual neurologic deficit memory
  and concentration significantly impaired
• Unable to work or care for babies
• Babies appear normal at 2 years of age

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Possible Outcomes

• Mother and babies die or brain-damaged
• Mother and babies intact
• Mother intact, babies die or impaired
• Mother brain damaged, babies intact
• Family takes legal action against hospital,
  anesthesiologist, obstetrician

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Cardiac Arrest in Pregnancy
What happens next depends on

• Maternal diagnosis
• Fetal condition and maturity
• How rapidly and appropriately medical and nursing
  personnel respond
• Resources available in hospital

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Cardiac Arrest in Pregnancy
What happens next depends on

• Maternal diagnosis
• Fetal condition and maturity
• How rapidly and appropriately medical and nursing
  personnel respond
• Resources available in hospital

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Morbidity and Mortality in Obstetric Anesthesia
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High Severity Injuries Associated with Regional
Anesthesia in the 1990sASA Closed Insurance
Claims Project
(Cheney F. ASA Newsletter 2001)
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Cardiac Arrest in PregnancyComplicated by
Physiologic Changes

• Rapid development of hypoxia, hypercapnia,
  acidosis
• Risk of pulmonary aspiration
• Difficult intubation
• AORTO-CAVAL COMPRESSION by pregnant uterus when
  mother supine
• Changes greater in multiple pregnancy, obesity

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Cardiac Arrest in PregnancySpecial Problems

• Cardiac output during closed chest massage in CPR
  only 30 normal
• Cardiac output in the supine pregnant woman is
  decreased 30-50 due to aortocaval compression
• Combined effect of above There may be NO
  cardiac output!

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Important Questions

• How should we perform Emergency Cardiac Care (CPR
  and ACLS) in the pregnant patient?
• Should we do anything differently?

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Guidelines 2000 for Cardiopulmonary
Resuscitation and Emergency Cardiac Care
An international evidence and science-based
consensus Whats new or different?

• Anticipatory treatment of cardiac arrest
• Emphasis on Automatic External Defibrillators
  (AEDs)
• Competent bag-mask ventilation - may be better
  than intubation attempts
• Use of amiodarone 300 mg IV (in place of
  lidocaine)
• Vasopressin 40 mg x 1 (alternative to repeated
  doses epinephrine 1 mg IV every 3-5 min)
• Family presence during resuscitation

Insufficient evidence to support efficacy
American Heart Association, 2000
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Cardiac Arrest in Pregnancy

• Anticipatory treatment
• Lateral or tilt position
• 100 oxygen
• IV fluid bolus
• Evaluate all drug therapy
• Basic Life Support
• Uterine displacement
• (manual, hip wedge, etc.)
• Compress higher on sternum than usual
• Advanced Cardiac Life Support

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Cardiopulmonary Resuscitation in Pregnancy
Standard ACLS (usual defibrillation) plus

• LEFT UTERINE DISPLACEMENT - how?
• EARLY ENDOTRACHEAL INTUBATION
• START CESAREAN SECTION BY 4 MIN
• (if gt 20 weeks) helps both mother and fetus
• EARLY OPEN CHEST MASSAGE ( 15 min)
• Consider cardiopulmonary bypass Amniotic fluid
  embolus, drug toxicity

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Cardiopulmonary Resuscitation in Pregnancy
Standard ACLS (usual defibrillation) plus

• LEFT UTERINE DISPLACEMENT - MANUAL
• EARLY ENDOTRACHEAL INTUBATION
• START CESAREAN SECTION BY 4 MIN
• (if gt 20 weeks) helps both mother and fetus
• EARLY OPEN CHEST MASSAGE ( 15 min)
• Consider cardiopulmonary bypass Amniotic fluid
  embolus, drug toxicity

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Resuscitation Drugs in Pregnancy
Use standard pharmacologic therapy
without modification (Guidelines for CPR. JAMA,
1992)

• Epinephrine, amiodarone, vasopressin,
  norepinephrine, dopamine as clinically indicated
• Epinephrine, atropine, lidocaine via trachea at 2
  to 2.5 times usual IV dose if no central access
• Greater acidosis and aortocaval compression may
  necessitate larger doses of bicarbonate

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Why is Urgent Delivery Indicated?

• Maternal brain damage may start at 4-6 min
• What is good for mother is usually good for baby
• Most intact newborns delivered within 5 min
• Closed chest massage is less effective with time
• CPR may be totally ineffective before
  delivery Many reports of mother coming back to
  life after delivery

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Cardiac Arrest in Pregnancy Older Approach

• lt 24 weeks
• Fetus non-viable - try not to deliver
• Mother is the only consideration
• gt 24 weeks
• Consider both mother and fetus
• Mother is 1st priority
• Monitor fetal well-being
• Try to avoid delivery before 32 weeks

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Cardiac Arrest in Pregnancy Current Approach

• lt 20 weeks uterine size
• Aortocaval compression not significant
• Delivery may not help
• gt 20-24 weeks uterine size
• Aortocaval compression significant (no venous
  return at low perfusion pressures)
• Start Cesarean Section by 4 minutes
• Delivery by 5 minutes

Cummins RO Advanced Cardiac Life Support.
American Heart Association, Dallas, 1997 Johnson
et al, Cardiopulmonary Resuscitation. In
Obstetric Anesthesia for Uncommon Disorders
Gambling and Douglas, WB Saunders, 1998
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Advantages of Early Delivery

• Aortocaval compression relieved Venous return
  ?, Cardiac output ?
• Ventilation improved Functional Residual
  Capacity ?
• Oxygenation improved
• Oxygen consumption ?, CO2 production ?
• Improved maternal and newborn survival

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Perimortem Cesarean Section

• Start by 4 minutes, deliver by 5 minutes
• May help even if performed later
• Have stat C/S kit available
• Perform operation in patients room Can move
  to OR after delivery
• Dont worry about sterility
• Vertical abdominal incision quickest
• Prepare for uterine hypotonia and bleeding

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Optimal Outcome
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Optimal Outcome
IS THIS REALISTIC

Immediate CPR
ACLS
IS THIS REALISTIC

Immediate CPR
ACLS
?
Þ
OUTSIDE THE OR?
OUTSIDE THE OR?
Early intubation
Early intubation
Left Uterine displacement
Left Uterine displacement
Start Cesarean by 4 min
Start Cesarean by 4 min
Delivery by 5 min
Delivery by 5 min
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Common Problems in Obstetrics

• Denial of problem ? delay in response
• Communication errors
• Obstetric staff not prepared for catastrophes
• Inadequate response from transfusion or labs
• Back-up help cannot find the Obstetric Suite!
• No specialty in-house surgeons (e.g., for airway,
  vascular, cardiac problems)
• No ICU facilities

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Preparation for Obstetric Emergencies

• Essential equipment immediately available
• Help for anesthesiologists, surgeons, nurses
• Written protocols for common emergencies
• Procedures for urgent lab tests (including
  coagulation tests) and reporting of results
• Mandatory training in CPR and ACLS for pregnant
  patients for all personnel
• Emergency drills / simulator training

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CODE OB
Protocol plans response, trains individuals,
identifies patients at risk

• Operator receives call - initiates Code OB
• Team includes
• Usual Code Blue team
• Obstetrician (in-house)
• Obstetric anesthesiologist
• Newborn resuscitation team and equipment
• Surgical nurse with emergency Cesarean tray
• Start CPR ACLS and prepare for C/S

(Selman, Lebowitz, Gambling. Anesthesiol. Suppl,
200194A90)
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What is Essential Equipment?

• Pulse oximeter
• Cardiac arrest cart defibrillator
• Automatic Electric Defibrillator (AED)?
• Cesarean section instruments
• Difficult intubation equipment (including LMA,
  jet ventilator, fiberoptic laryngoscope)
• Thoracotomy instruments
• Blood warmer and rapid fluid infuser
• Central venous and arterial line equipment
• Malignant hyperthermia kit

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Spinal Anesthesia for Cesarean Section
Major problem with spinal anesthesia
is HYPOTENSION

• High incidence (50-85)
• Can be severe or prolonged
• Maternal nausea and vomiting
• Maternal cardiovascular collapse

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Collapse after High or Total Spinal Block

• Uncomplicated spinal block (multiple
  gestation, obese patients)
• Unintended spinal injection of epidural dose
• Subdural injection of epidural dose
• Epidural dose after dural puncture (CSE)
• Repeated spinal/epidural blocks

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High Incidence of Cardiac Arrest Following Spinal
Anesthesia
J. Pollard, Anesthesiology 200296515

• Incidence as high as 11000 - 11600 surgical
  cases
• Death or brain damage in 90 patients
• Vagal predominance important contributor
• Treatment should include
• Strong vagolytic agent (atropine)
• Alpha- or mixed agonists (phenylephrine,
  epinephrine)
• Fluids (colloids, crystalloid)

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Management of High Spinal in Pregnancy

• Evaluate severity and progression of symptoms
• Left uterine displacement
• DO NOT elevate patients head - ? cerebral
  perfusion
• 100 O2 by mask
• Cricoid pressure, mask ventilation
• Intubate (thiopental, succinylcholine only if
  patient awake)
• Rapid infusion of crystalloid, colloids
• Bradycardia treat with atropine
• Pressors
• Ephedrine, Phenylephrine, Epinephrine

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Cardiac Arrest During Regional Block

• High sympathetic block
• Cardio-accelerators (T1 - 4) blocked
• Complete vasodilation ? No venous return
• Vagal predominance
• Vasopressin may be better than epinephrine
• Vasoconstrictor at high doses
• Transfers blood from peripheral to central
  compartment
• Prolonged action of single dose (10-20 min 1/2
  life)
• Fewer adverse effects than epinephrine

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Epinephrine vs. Vasopressin for Resuscitation
during Epidural Anesthesia (in pigs)Coronary
Perfusion Pressure after Epidural Saline
DA1 45 µg/kg epinephrine vs. 0.4 U/kg
vasopressin DA2 45 µg/kg epinephrine vs. 0.4
U/kg vasopressin DA3 200 µg/kg epinephrine vs.
0.8 U/kg vasopressin ROSC return of
spontaneous circulation. Plt0.05 vasopressin
vs epinephrine Horizontal dashed line
approximate threshold needed for successful
resuscitation.
(Krismer et al. Anesth Analg, 200193734)
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Epinephrine vs. Vasopressin for Resuscitation
during Epidural Anesthesia (in pigs)Coronary
Perfusion Pressure after Epidural Bupivacaine
DA1 45 µg/kg epinephrine vs. 0.4 U/kg
vasopressin DA2 45 µg/kg epinephrine vs. 0.4
U/kg vasopressin DA3 200 µg/kg epinephrine vs.
0.8 U/kg vasopressin ROSC return of
spontaneous circulation. Plt0.05 vasopressin
vs epinephrine Horizontal dashed line
approximate threshold needed for successful
resuscitation.
(Krismer et al. Anesth Analg, 200193734)
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The Efficacy of Epinephrine and Vasopressin for
Resuscitation during Epidural Anesthesia (in
pigs)
Krismer et al. Anesth Analg, 200193734

• Vasopressin lasted longer than epinephrine
• Greater acidosis with epinephrine
• Post-resuscitation, more hypertension and
  tachycardia after epinephrine
• Trend to better survival with vasopressin
• Bradycardia requiring atropine more frequent
  after vasopressin
• Vasopressin may be a more desirable vasopressor
  for resuscitation during epidural blockade

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The Cesarean Delivery Decision - Not an Easy One!

• Has 3-4 min passed since cardiac arrest?
• Has the mother responded to resuscitation?
• Was resuscitation optimal - can it be improved?
• Is an immediately treatable condition (e.g,
  seizures) present? If so, C/S may not be
  necessary

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The Cesarean Delivery Decision - Not an Easy One!

• Has the mother suffered an inevitably fatal
  injury?
• Has so much time passed that maternal survival
  with good outcome is impossible?
• In most cases in late pregnancy, immediate
  delivery benefits mother and/or baby

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Summary

• Cardiac arrest is the final common pathway for
  many conditions
• Maternal and fetal survival depend on rapid and
  skilled resuscitation
• Consider early (lt 5 min) Cesarean delivery
• Training in ACLS for pregnant woman essential for
  maternity unit personnel
• Be prepared!!

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Summary

• Cardiac arrest is the final common pathway for
  many conditions
• Maternal and fetal survival depend on rapid and
  skilled resuscitation
• Consider early (lt 5 min) Cesarean delivery
• Training in ACLS for pregnant woman essential for
  maternity unit personnel
• Be prepared!!

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Summary

• Cardiac arrest is the final common pathway for
  many conditions
• Maternal and fetal survival depend on rapid and
  skilled resuscitation
• Consider early (lt 5 min) Cesarean delivery
• Training in ACLS for pregnant woman essential for
  maternity unit personnel
• Be prepared!!