Critical Care in Obstetrics

1
Critical Care in Obstetrics Sina Haeri, MD MHSA
FACOG University of North Carolina at Chapel
Hill Division of Maternal-Fetal Medicine
2
Disclosures I have no conflicts of interest or
financial disclosures to make.
3

• Outline
• Epidemiology of critical illness in pregnancy
• Overview of normal pregnancy physiology
• Pulmonary PEARLS Pitfalls
• Cardiac PEARLS Pitfalls
• Hypertensive PEARLS Pitfalls
• Hemorrhage PEARLS Pitfalls
• Perimortem management

4

• Outline
• Epidemiology of critical illness in pregnancy
• Overview of normal pregnancy physiology
• Pulmonary PEARLS Pitfalls
• Cardiac PEARLS Pitfalls
• Hypertensive PEARLS Pitfalls
• Hemorrhage PEARLS Pitfalls
• Perimortem management

5

• Epidemiology of critical care in OB
• Definition
• Impending, developing, or established
  significant organ dysfunction, which may lead to
  long-term morbidity or death. (Dildy et al.
  Critical Care Obstetrics, 4th edition)
• Statistics
• 0.11-0.89 of all deliveries in the US result in
  ICU admissions (Gilbert et al. Obstet Gynecol,
  2003 897-903)
• Generally, 75 of all ICU admissions in
  pregnancy are during the post-partum period
  (Mahutte et al. Obstet Gynecol, 1999 263-266)

6
Epidemiology of critical care in OB Objective
criterion for admission to the ICU Vital
signs Laboratory values HR lt40 or gt150 bpm Na
lt110 or gt170 mEq/L SBP lt80 mmHg K lt2 or gt7
mEq/L DBP gt120 mmHg PaO2 lt50 mmHg MAP lt60
mmHg pH lt7.1 or gt7.7 RR gt35/min Ca gt15 mg/dL,
Gluc gt800 mg/dL Imaging ECG Intracrani
al hemorrhage MI (with arrhythmia, CHF) Ruptured
viscus SVT or V-Fib Dissecting AAA Complete
heart block (Guidelines for ICU admission,
triage, discharge. Crit Care Med, 1999
633-638)
7
Epidemiology of critical care in OB Objective
criterion for admission to the ICU Vital
signs Laboratory values HR lt40 or gt150 bpm Na
lt110 or gt170 mEq/L SBP lt80 mmHg K lt2 or gt7
mEq/L DBP gt120 mmHg PaO2 lt50 mmHg MAP lt60
mmHg pH lt7.1 or gt7.7 RR gt35/min Ca gt15 mg/dL,
Gluc gt800 mg/dL Imaging ECG Intracrani
al hemorrhage MI (with arrhythmia, CHF) Ruptured
viscus SVT or V-Fib Dissecting AAA Complete
heart block (Guidelines for ICU admission,
triage, discharge. Crit Care Med, 1999
633-638)
8
Epidemiology of critical care in OB Objective
criterion for admission to the ICU Vital
signs Laboratory values HR lt40 or gt150 bpm Na
lt110 or gt170 mEq/L SBP lt80 mmHg K lt2 or gt7
mEq/L DBP gt120 mmHg PaO2 lt50 mmHg MAP lt60
mmHg pH lt7.1 or gt7.7 RR gt35/min Ca gt15 mg/dL,
Gluc gt800 mg/dL Imaging ECG Intracrani
al hemorrhage MI (with arrhythmia, CHF) Ruptured
viscus SVT or V-Fib Dissecting AAA Complete
heart block (Guidelines for ICU admission,
triage, discharge. Crit Care Med, 1999
633-638)
9
Epidemiology of critical care in OB Objective
criterion for admission to the ICU Vital
signs Laboratory values HR lt40 or gt150 bpm Na
lt110 or gt170 mEq/L SBP lt80 mmHg K lt2 or gt7
mEq/L DBP gt120 mmHg PaO2 lt50 mmHg MAP lt60
mmHg pH lt7.1 or gt7.7 RR gt35/min Ca gt15 mg/dL,
Gluc gt800 mg/dL Imaging ECG Intracrani
al hemorrhage MI (with arrhythmia, CHF) Ruptured
viscus SVT or V-Fib Dissecting AAA Complete
heart block (Guidelines for ICU admission,
triage, discharge. Crit Care Med, 1999
633-638)
10
Epidemiology of critical care in OB Objective
criterion for admission to the ICU Vital
signs Laboratory values HR lt40 or gt150 bpm Na
lt110 or gt170 mEq/L SBP lt80 mmHg K lt2 or gt7
mEq/L DBP gt120 mmHg PaO2 lt50 mmHg MAP lt60
mmHg pH lt7.1 or gt7.7 RR gt35/min Ca gt15 mg/dL,
Gluc gt800 mg/dL Imaging ECG Intracrani
al hemorrhage MI (with arrhythmia, CHF) Ruptured
viscus SVT or V-Fib Dissecting AAA Complete
heart block (Guidelines for ICU admission,
triage, discharge. Crit Care Med, 1999
633-638)
And of course, objective Physical Exam
criterion Airway obstruction Anuria Burns gt10
of body surface area Cardiac tamponade Coma Contin
ous seizures Cyanosis Unequal pupils (unconscious
patient)
11
Epidemiology of critical care in OB Medical
complications during pregnancy leading to an ICU
admission Data summarized from
18 studies Dildy et al. Critical Care
Obstetrics, 4th edition.
12
Epidemiology of critical care in OB Pregnancy
related maternal deaths in the US1
PRMR Pregnancy related mortality ratio per
100,000 live births Koonin et al. MMWR
199756-17-36.
13
Epidemiology of critical care in OB Top causes
of mortality in obstetric patients admitted to
the ICU1 Data summarized from 16
studies Dildy et al. Critical Care Obstetrics,
4th edition.
14
Epidemiology of critical care in OB Anesthesia
specific complications - Allergic reaction -
Failed intubation - High spinal
15

• Outline
• Epidemiology of critical illness in pregnancy
• Overview of normal pregnancy physiology
• Pulmonary PEARLS Pitfalls
• Cardiac PEARLS Pitfalls
• Hypertensive PEARLS Pitfalls
• Hemorrhage PEARLS Pitfalls
• Perimortem management

16

• Pregnancy physiology
• Physiologic adaptation occur in the gravid mother
  to accommodate new demands
• Support of the fetus
• Protection of the fetus
• Preparation of the uterus for labor
• Protection of the mother from labor

Volume support Nutritional/oxygen support Fetal
waste clearance
17

• Pregnancy physiology
• Physiologic adaptation occur in the gravid mother
  to accommodate new demands
• Support of the fetus
• Protection of the fetus
• Preparation of the uterus for labor
• Protection of the mother from labor

From starvation From toxins From drugs
18

• Pregnancy physiology
• Physiologic adaptation occur in the gravid mother
  to accommodate new demands
• Support of the fetus
• Protection of the fetus
• Preparation of the uterus for labor
• Protection of the mother from labor

19

• Pregnancy physiology
• Physiologic adaptation occur in the gravid mother
  to accommodate new demands
• Support of the fetus
• Protection of the fetus
• Preparation of the uterus for labor
• Protection of the mother from labor

20

• Pregnancy physiology
• Cardiovascular adaptations
• Increased plasma volume
• Hemodilution
• Blood pressure variability (CO x SVR)
• Increased heart rate
• Increased cardiac output (HR x SV)
• SVR variability

?10 by 7th week Plateau at 50 by 32
weeks Larger increase in multiples (1570 ml vs.
1960 ml) Accompanied by ?RBC mass Important for
fetal growth (?IUGR with lower PV) Result of
contribution from mother fetus
21

• Pregnancy physiology
• Cardiovascular adaptations
• Increased plasma volume
• Hemodilution
• Blood pressure variability (CO x SVR)
• Increased heart rate
• Increased cardiac output (HR x SV)
• SVR variability

?RBC mass lt ?PV Better placental perfusion? ?
Blood viscocity ? Stasis ? Placental
thrombosis Protective during delivery
22

• Pregnancy physiology
• Cardiovascular adaptations
• Increased plasma volume
• Hemodilution
• Blood pressure variability
• Increased heart rate
• Increased cardiac output (HR x SV)
• SVR variability

BP CO x SVR Influenced by GA position ?10
by 7th week (likely due to progesterone) Initial
drop is SBP 2? to ?SVR (?MAP in 1st
trimester) BP decreases until 28 weeks Points
of concern Method Position
23

• Pregnancy physiology
• Cardiovascular adaptations
• Increased plasma volume
• Hemodilution
• Blood pressure variability (CO x SVR)
• Increased heart rate
• Increased cardiac output (HR x SV)
• SVR variability

?20 in pregnancy Likely 2? to ?SVR Some impact
from ?FT4 Must always be weary of other
causes Plays important role in certain diagnoses
(i.e. mitral stenosis)
24

• Pregnancy physiology
• Cardiovascular adaptations
• Increased plasma volume
• Hemodilution
• Blood pressure variability (CO x SVR)
• Increased heart rate
• Increased cardiac output
• SVR variability

CO HR x SV Reflects LV capacity Increases by
10th week Peaks (30-50) at 26 weeks (4.5 L/min
? 6.0 L/min) 2? to HR before 20 weeks 2? to SV
after 20 weeks
25

• Pregnancy physiology
• Cardiovascular adaptations
• Increased plasma volume
• Hemodilution
• Blood pressure variability (CO x SVR)
• Increased heart rate
• Increased cardiac output (HR x SV)
• SVR variability

Measure of impedance to maternal after
load Decreases in 1st/2nd trimester (Nadir by
14-24 weeks) Increases in 3rd trimester Inversel
y proportional to CO
26

• Pregnancy physiology
• Cardiovascular adaptations (during labor)
• ?CO (35) ?HR (7) during contractions
• Supine?Lateral position22?CO 27?SV
• ?CO during contractions
• 17 at less than 3 cm
• 23 at 4-7 cm
• 35 at 8 cm or more
• (Offset by regional anesthesia)

27

• Pregnancy physiology
• Cardiovascular adaptations (post partum)
• Impacted by blood loss at delivery
• Increased CO (59) SV (71) within 1-3 hours
• Maximal diuresis on days 2-5
• Vaginal vs. Cesarean
• Loss 500 ml 1000 ml
• ? Hct 5.2 -5.8

28

• Pregnancy physiology
• Pulmonary adaptations
• Upper airways
• Mechanics of respiration
• Physiologic changes
• Acid-base changes

?Mucosal edema ?Mucosal vascularity ?Rhinitis
Epistaxis
29

• Pregnancy physiology
• Pulmonary adaptations
• Upper airways
• Mechanics of respiration
• Physiologic changes
• Acid-base changes

8? thoracic circumference 5 cm elevation of
diaphragm Increase in dyspnea 15 by 10
weeks 50 by 19 weeks 76 by 31 weeks
30

• Pregnancy physiology
• Pulmonary adaptations
• Upper airways
• Mechanics of respiration
• Physiologic changes
• Acid-base changes

FEV1 Unchanged FRC ?10-25 TLC ?
minimally Minute Vent ?20-40 Alveolar
Vent ?50-75
31

• Pregnancy physiology
• Pulmonary adaptations
• Upper airways
• Mechanics of respiration
• Physiologic changes
• Acid-base changes

PregnancyCompensated respiratory
alkalosis ? CO2 diffuses faster than
O2 ? Decreased PaCO2 (27-34) ? Increased bicarb
(18-21) ? pH between 7.40 and 7.45 ?PaO2
(101-104) ?A-a gradient (14.3)
32

• Pregnancy physiology
• Other adaptations
• Genitourinary
• Gastrointestinal
• Hematologic
• Endocrine
• Immune

33

• Outline
• Epidemiology of critical illness in pregnancy
• Overview of normal pregnancy physiology
• Pulmonary PEARLS Pitfalls
• Cardiac PEARLS Pitfalls
• Hypertensive PEARLS Pitfalls
• Hemorrhage PEARLS Pitfalls
• Perimortem management

34
Pulmonary-ARDS Definition (American-European
Consensus Committee) - Acute onset - Presence
of bilateral infiltrates on imaging - No
evidence of LA hypertension Rapid
progression Respiratory failure within 48
hours Follows a predictable phase -
Acute/exudative - Proliferation/fibrosis -
Repair/recovery (75 residual disease)
35
Pulmonary-ARDS Manifestation - Hypoxemia (R-L
Shunting) - ? Pulmonary compliance (Be careful
with PEEP) - ? Airway resistance (?Barotrauma
risk, hard to wean) - ? Physiologic deadspace
(permissive hypercapnia) - Pulmonary HTN (most
often transient)
36
Pulmonary-ARDS Management - Identify
eliminate source - Use minimal FiO2 necessary
(O2 goal 90) - Maintain minimum Hg of 10
g/dL - Exclude cardiogenic pulmonary edema -
Monitor fluid status closely Overall Goal
Minimize further injury provide adequate
support!
37
Pulmonary-ARDS Management - Identify
eliminate source - Use minimal FiO2 necessary
(O2 goal 90) - Maintain minimum Hg of 10
g/dL - Exclude cardiogenic pulmonary edema -
Monitor fluid status closely Overall Goal
Minimize further injury provide adequate
support!
Other attempted therapies ECMO (trials
failed) ECCO2R (investigational) Corticosteroids
(no proven benefit) Surfactant (no proven
benefit) Nitric Oxide (failed phase II/III
trials, rebound vasoconstriction) Immunotherapy
(anti-CD11b antibodies investigational) Prostagla
ndin Inhibitors (Ibuprofen some benefit in
GNS) Antioxidants (N-acetylcysteine
investigational)
38

• Pulmonary-Pulmonary Edema
• Causes
• Hydrostatic
• Systolic dysfunction
• Diastolic dysfunction
• Valvular disease
• Permeability
• Pneumonia
• Septic shock
• ARDS
• Other
• Tocolytic induced
• Preeclampsia

39

• Pulmonary-Pulmonary Edema
• Causes
• Hydrostatic
• Systolic dysfunction
• Diastolic dysfunction
• Valvular disease
• Permeability
• Pneumonia
• Septic shock
• ARDS
• Other
• Tocolytic induced
• Preeclampsia

40

• Pulmonary-Pulmonary Edema
• Causes
• Hydrostatic
• Systolic dysfunction
• Diastolic dysfunction
• Valvular disease
• Permeability
• Pneumonia
• Septic shock
• ARDS
• Other (i.e. decreased colloid)
• Tocolytic induced
• Preeclampsia

41

• Pulmonary-Pulmonary Edema
• Treatment (general)
• Sit patient upright
• Administer oxygen (may use CPAP until diuresis)
• Furosemide (aim for 2L diuresis in 3-4 hours)
• Morphine (2-5 mg IV)
• Treatment (Specific)
• Systolic dysfunction (afterload
  reduction/inotrop/diuretic)
• Diastolic dysfunction (anti-HTN)

42

• Pulmonary-Status Asthmaticus
• Indications for intubation
• Inability to maintain O2 sat. above 90
• Inability to maintain PaCO2 less than 40 mmHg
• Maternal exhaustion
• Worsening acidosis (pH lt 7.20-7.25)
• Altered mental consciousness
• Ventilator settings (to avoid DHI)
• Tidal volume of 8-10 mL/kg
• Inspiratory flow rate 80-100 L/min
• Respiratory rate 11-14/min

43

• Pulmonary-Status Asthmaticus
• Indications for intubation
• Inability to maintain O2 sat. above 90
• Inability to maintain PaCO2 less than 40 mmHg
• Maternal exhaustion
• Worsening acidosis (pH lt 7.20-7.25)
• Altered mental consciousness
• Ventilator settings (to avoid DHI)
• Tidal volume of 8-10 mL/kg
• Inspiratory flow rate 80-100 L/min
• Respiratory rate 11-14/min

44

• Pulmonary-Status Asthmaticus
• Indications for intubation
• Inability to maintain O2 sat. above 90
• Inability to maintain PaCO2 less than 40 mmHg
• Maternal exhaustion
• Worsening acidosis (pH lt 7.20-7.25)
• Altered mental consciousness
• Ventilator settings (to avoid DHI)
• Tidal volume of 8-10 mL/kg
• Inspiratory flow rate 80-100 L/min
• Respiratory rate 11-14/min

Other modalities in the acute pregnant
setting Cromolyn sodium (preventative, not
useful in acute event) Antihistamines
(inconsistent, may decrease pulmonary
function) Empiric antibiotics (no proven
benefit) Iodides (neonatal hypothyroidism/goiter/
airway obstruction) Sodium bicarbonate (will
dimish CO2 transfer from fetus?maternal
alkalosis) If in Labor Stress dose
steroids Fentanyl for pain (rather than
meperidine or morphine)
45
Pulmonary-ABG Pitfalls Significant Heparin in
syringe can ?PCO2 Dilutional error when using an
arterial catheter Air bubbles/froth can
?PO2 Room temperature can ?pH/PO2 and
?PCO2 GETA with halothane will falsely
?PO2 Severe leukocytosis will falsely lead to
?PO2
46

• Outline
• Epidemiology of critical illness in pregnancy
• Overview of normal pregnancy physiology
• Pulmonary PEARLS Pitfalls
• Cardiac PEARLS Pitfalls
• Hypertensive PEARLS Pitfalls
• Hemorrhage PEARLS Pitfalls
• Perimortem management

47
Cardiac PEARLS Best predictors of a cardiac
event in pregnancy (CARPREG Risk Index) - NYHA
Class III or IV - Obstructed left heart - Prior
cardiac event (CHF, arrhythmia, TIA, stroke) -
Ejection fraction lt 40 Pulmonary edema,
arrhythmia, stroke, and/or death
48
Cardiac PEARLS ACC/AHA/ESC High Risk
categories - Severe aortic stenosis - Mitral
stenosis (NYHA II-IV) - Aortic/Mitral
regurgitation (NYHA III-IV) - Aortic/Mitral
valve disease with severe left ventricular
dysfunction (EF lt40) - Marfan syndrome -
Mechanical prosthetic valve
49
Cardiac PEARLS Management categories ?SVR
Acceptable ?SVR Unacceptable (Regional
anesthesia ok) (Regional anesthesia
risky) Mitral stenosis Coarctation of
aorta Mitral insufficiency Aortic
stenosis Aortic insufficiency TOF
(uncorrected) Pulmonic stenosis Pulmonary
HTN Pulmonic insufficiency IHSS Triscuspid
disease Eisenmengers MI Cardiomyopathy
50
Cardiac PEARLS Management categories ?SVR
Acceptable ?SVR Unacceptable (Regional
anesthesia ok) (Regional anesthesia
risky) Mitral stenosis Coarctation of
aorta Mitral insufficiency Aortic
stenosis Aortic insufficiency TOF
(uncorrected) Pulmonic stenosis Pulmonary
HTN Pulmonic insufficiency IHSS Triscuspid
disease Eisenmengers MI Cardiomyopathy
Run them even Too wet - Pulmonary edema -
Arrhythmia Too dry - Hypoperfusion
51
Cardiac PEARLS Management categories ?SVR
Acceptable ?SVR Unacceptable (Regional
anesthesia ok) (Regional anesthesia
risky) Mitral stenosis Coarctation of
aorta Mitral insufficiency Aortic
stenosis Aortic insufficiency TOF
(uncorrected) Pulmonic stenosis Pulmonary
HTN Pulmonic insufficiency IHSS Triscuspid
disease Eisenmengers MI Cardiomyopathy
Run them wet Too wet - Pulmonary edema Too
dry - Syncope/MI - Sudden death
52
Cardiac PEARLS General intrapartum management
notes - Induction under controlled
conditions - Oxytocin/mechanical ripening
preferred - Dinoprostone/Misoprostol
contraindicated - Lateral decubitus position -
Assisted second stage of labor - Epidural may be
used cautiously - Arterial catheter for
monitoring - CS for obstetrical
indications Theoretical considerations
coronary vasospasms, arrhythmias, blood pressure
effects
53

• Outline
• Epidemiology of critical illness in pregnancy
• Overview of normal pregnancy physiology
• Pulmonary PEARLS Pitfalls
• Cardiac PEARLS Pitfalls
• Hypertensive PEARLS Pitfalls
• Hemorrhage PEARLS Pitfalls
• Perimortem management

54
Hypertension-Definitions Hypertensive
urgency - DBPgt120 mmHg - Acute rise in MAP gt30
mmHg - Asymptomatic Hypertensive emergency -
SBP gt180 mmHg - DBP gt120 mmHg - Presence of
end-organ-damage BP Flow x Resistance
55
Hypertension-Urgency Hypertensive urgency
associated morbidity - Hypertensive
encephalopathy - Acute heart failure - MI -
Stroke - Renal impairment - Eclampsia/HELLP
Syndrome - Placental abruption - Fetal demise
in utero
56
Hypertension-PEARLS Causes of severe
hypertension (BP Flow x Resistance) Increased
flow vs. Increased resistance Hypervolemia Coc
aine Increased cardiac output Pain Increased
contractility Hypoxia Increased
ICP Hyperthyroidism Preeclampsia Pheoc
hromocytoma
57
Hypertension-PEARLS SBP ?Interaction between SV
vasoconstriction DBP ?Vasoconstriction Using
PP to determine cause PP lt 55 mmHg?Increased
flow PP gt 55 mmHg?Increased resistance
58
Hypertension-PEARLS Treatment
strategies Increased flow vs. Increased
resistance Decrease fluids/Na Control
pain Beta-blockade Adjust volume status Loop
diuretic Vasodilator Vasodilator Address
underlying cause if hormonal
59

• Outline
• Epidemiology of critical illness in pregnancy
• Overview of normal pregnancy physiology
• Pulmonary PEARLS Pitfalls
• Cardiac PEARLS Pitfalls
• Hypertensive PEARLS Pitfalls
• Hemorrhage PEARLS Pitfalls
• Perimortem management

60
Hemorrhage-Fluid resuscitation (Goal-prompt
restoration of intravascular volume) Crystalloids
(Ringers Lactate/Normal Saline) Pros Cons Re
adily available Less effective at IVV
expansion Easy to store 2-12 times volume
needed in total Non-toxic Peripheral
edema Reaction free Bowel edema Pulmonary edema
less likely
61
Hemorrhage-Fluid resuscitation (Goal-prompt
restoration of intravascular volume) Colloids
(Albumin/Hetastarch) Albumin Hetastarch
(Hespan) Water soluble Synthetic
colloid Available at 5, 25 HTS Available at 6
NS Should be administered with IVF Volume
expansion similar to Albumin Half life 16
hours Half life 24 hours 90 in plasma after 2
hours Increases Amylase 2-3 fold Use 5 in
non-edematous pts 0.1 anaphylaxis rate Use 25
in edematous pts May exacerbate pulm
edema Negative inotropic effect (via
Ca) 0.5-1.5 anaphylaxis rate
62

• Hemorrhage-Resuscitation
• Fluid management in setting of acute blood loss
• Use crystalloids 31 to blood loss volume
• 2/3 of crystalloid volume will redistribute
  rapidly

63

• Outline
• Epidemiology of critical illness in pregnancy
• Overview of normal pregnancy physiology
• Pulmonary PEARLS Pitfalls
• Cardiac PEARLS Pitfalls
• Hypertensive PEARLS Pitfalls
• Hemorrhage PEARLS Pitfalls
• Perimortem management

64

• Perimortem-PEARLS
• Emergency cardiac care in pregnancy
• (the modifications)
• Heimlich manuever (chest thrust in 2nd/3rd
  trimesters)
• Left uterine diplacement
• Aggressive airway management
• Cricoid pressure to avoid aspiration
• Increase chest wall compression force
• Delivery within 5 minutes if fetus is viable
• Aggressive restoration of circulatory volume

65
Perimortem-PEARLS Lex Caesare (Cesarean
delivery should be performed within 5
minutes) Outcomes of surviving infants
following perimortem CS