Embolism

Question 1

Among women who died after live birth the leading causes of death are

Answer 1

Embolism and PIH

Question 2

Types of embolisms

Answer 2

Venous thromboembolism
PE
VAE
Amniotic fluid embolism

Question 3

What is the risk of VTE with pregnancy

Answer 3

5-10x the risk

Question 4

What physiological adaptions is VTE caused by

Answer 4

Venous stasis
Hypercoagulability
Damage to vessel wall
Virchows triad

Question 5

Risk factors for VTE

Answer 5

> 35 y.o
Higher parity
Obesity
Prolonged immobilization
Surgery during pregnancy aka CS
Family or personal history
Pre-eclampsia
Pelvic trauma
Hereditary thrombophilia protein C and S deficiency

Question 6

Clinical signs of PE

Answer 6

Most common: tachypnea and sudden onset of dyspnea

Tachycardia, desaturation

Question 7

Lab findings with a PE

Answer 7

Hypoxemia
Resp alkalosis
Normal chest x ray

Question 8

EKG findings with a PE

Answer 8

RV strain
ST segment abnormality
T wave inversion
Supraventricular arrhythmias

Question 9

Respiratory failure, pulmonary HTN for PE may result from

Answer 9

Respiratory failure occurs from the occlusion of the pulmonary vasculature (V/Q mismatch), and pulmonary edema due to increased hydrostatic forces and the disruption of normal capillary integrity
Pulmonary HTN results from direct vascular obstruction and results in RV overload

Question 10

Invasive monitoring with a PE reveals

Answer 10

Normal to low PA occlusion pressures
Increased mean PAP
Increased CVP

Question 11

Diagnostic tests used for pE

Answer 11

V/Q scans
MRA
Spiral CT
Pulm angio

Question 12

Pulm angio is required in

Answer 12

Patients who have a negative V/Q scan but strong clinical suspicion of PE or in severe cases for confirmation of PE before thrombolysis

Question 13

What is the radiation dose to the fetus with a combination of CXR, V/Q scan, pulm angio

Answer 13

0.5 rad

> 5 is significant for tetratogenesis

Question 14

Supportive measures for PE/VTE

Answer 14

Improve Oxygenation and circulation, O2 administration and cardiorespiratory support with fluids inotropes and vasopressors
RA filling pressures should be maintained at a high level to maintain output from the failing RV

Question 15

Specific therapy for VTE/PE

Answer 15

Anticoag (heparin, LMWH)

Thrombolysis

Question 16

What thrombolytics can be used during pregnancy

Answer 16

Streptokinase or urokinase, and r-tpa

Urokinase is less antigenic and should have fewer side effects

Question 17

Does not induce systemic fibrinolysis but is active when bound to thrombin so it is clot specific

Answer 17

R-TPA

Question 18

Antepartum and intrapartum complications from thrombolysis includes

Answer 18

Maternal hemorrhage and placental abruption

Question 19

Which is the therapy of choice between heparin and LMWH

Answer 19

Unfractionated heparin

Question 20

Dosing with heparin

Answer 20

Iv bolus then an infusion for PTT 1.5 to 2x the upper level of control values for 10-14 days
Followed by subq injections 5k-10ku q8-12 hours throughout pregnancy

Question 21

When is heparin d/c

Answer 21

Shortly before delivery and restarted with warfarin

When the INR is between 2-3

Question 22

Controversial during pregnancy for thromboprophylaxis

Answer 22

LMWH

Question 23

Greater antithrombotic activity (factor xa) than anticoagulant activity (anti factor IIa)
it does not affect the aPTT

Answer 23

LMWH

Question 24

Why does the smaller structure of LMWH have advantages over heparin

Answer 24

Prolonged serum half life
Decreased daily dosing
Lower protein binding
Lower risk of bleeding, and platelet activation and thrombocytopenia

Question 25

How can air be demonstrated during CS

Answer 25

By precordial doppler auscultation

Question 26

Risk factors for VAE

Answer 26

Gradient of -5cm H2O between periphery and the heart would allow significant entry of air into venous circulation Trendelenburg and exteriorizing the uterus during CS increases the gradient

Question 27

Uterine exteriorization predisposes to VAE by

Answer 27

Increasing the hydrostatic gradient by raising the incisional are above the level of the heart By enlargement of the uterine sinuses providing more exposure to air

Question 28

What physiologic occurrence causes death from VAE is

Answer 28

Circ arrest from air entrapped in the RV outflow tract 5ml/kg of air lethal for air lock in RV or in pulmonary arterial circ Can result in cardiogenic shock

Question 29

VAE with PA vasoconstriction can result in

Answer 29

Acute cor pulmonale

Question 30

Air on endothelial surfaces results in

Answer 30

Increased capillary permeability, platelet activation, and coagulopathy

Question 31

Massive VAE presents as

Answer 31

Hypotension, hypoxemia, cardiac arrest

Question 32

6 signs of air embolism

Answer 32

``` Decreased end tidal Chest pain Tachypnea, dyspnea Cyanosis/mottled skin Wheel mill murmur auscultated through steth Tachycardia and hypotension ```

Question 33

Resuscitation steps for massive PE

Answer 33

1. D/c nitrous and give 100% fio2 2. Prevent further air entrapment flood surgical field, change position 3. Support ventilation as needed 4. Support circ 5. Consider placement of central line to aspirate 6. Expedite delivery 7. Delayed emergence from GA consider neurodiagnostic imaging to r/o intracerebral air (arterial gas embolism) benefit from hyperbaric therapy within 5 hours

Question 34

The leading cause of mortality during labor and first few PP hours

Answer 34

AFE

Question 35

Maternal death with AFE occurs in one of three ways

Answer 35

1. Sudden cardiac arrest 2. DIC 3. ARDS MOF

Question 36

Causes of AFE

Answer 36

Tear in amnion or chorion Opens uterine and endocervical veins Pressure is high to force amniotic fluid into venous circulation

Question 37

Risk factors for AFE

Answer 37

``` Advanced age Multiparity Tumultuous labor ROM Fetal death Trauma Uterine overdistension ```

Question 38

Aminotic fluid components that are biochemical mediators causing major effects and anaphylactoid reaction and multi system involvement

Answer 38

``` Surfactant Endothelin Leukotrienes C4 D4 Thromboxane A2 Prostaglandins Arachidonic acid Thromboplastin Collagen tissue factor III Phospholipase A2 PF III ```

Question 39

Suspension amniotic fluid components causing minor effects and mechanical obstruction

Answer 39

``` Lanugo hair Vernix caseosa Fetal squames Bile stained meconium Fetal gut mucin Trophoblasts ```

Question 40

Intermediate phase of anaphylactoid reaction to AFE

Answer 40

``` Occurs when initially exposed Respiratory distress Cyanosis Hemodynamic instability Cerebral hypoperfusion with seizures, confusion, coma ```

Question 41

Second phase of anaphylactoid reaction to afe

Answer 41

Coagulopathy and hemorrhage | First and only presentation of AFE possibly

Question 42

Third phase of anaphylactoid reaction to AFE

Answer 42

Tissue injury is established | Die from lung or brain injury, MOF, or infection acquired during ICU

Question 43

Clinical manifestations of afe

Answer 43

``` Nonspecific 1. Respiratory distress 2. Cyanosis 3. CV collapse 4. Coma 5. Hemorrhage Hemorrhage and fetal distress initial symptoms ```

Question 44

Diagnosis of AFE

Answer 44

CXR maybe normal EKG RV strain early on ECHO - severe LV failure Difficult to do specific testing d/t hemodynamic instability

Question 45

Past diagnosis of AFE

Answer 45

Autopsy by finding fetal squamous cells in maternal pulm circulation

Question 46

AFE treatment is supportive and directed towards

Answer 46

``` Oxygenation CO, SBP >90 Organ perfusion UO >25ml/hr Coag corrections Uterine toning ```

Question 47

Pharmacologic management if afe

Answer 47

Crystalloids, pressors, inotropic support Restrict fluids after first hypotensive episode resolved to prevent pulm edema and ARDS Corticosteroids hydrocort 500mg qh/hr Heparin is controversial CPB and thromboembolectomy

Question 48

T or F therapy for PE focuses on prevention of recurrent PEs

Answer 48

T

Question 49

T or F AFE may occur at any time during L and D

Answer 49

T