Embolism during Pregnancy - PowerPoint Presentation

Slide1

Embolism during Pregnancy

Robert Nichols, DOSlide2

Embolism

Pulmonary Embolism

Venous Air Embolism

Amniotic Fluid embolismSlide3

Embolism

One of the leading causes of maternal mortality

Non-cardiovascular diseases, 15.3%.

Cardiovascular diseases, 14.7%.

Infection or sepsis, 12.7%.

Hemorrhage, 11.3%.Cardiomyopathy, 10.8%.Thrombotic pulmonary embolism, 9.0%.Hypertensive disorders of pregnancy, 7.6%.Cerebrovascular accidents, 6.5%.Amniotic fluid embolism, 5.7%.Anesthesia complications, 0.2%.www.cdc.gov/reproductivehealth/maternalinfanthealth/pmss.htmlSlide4

Pulmonary Embolism

Difficult diagnosis and management

2 patients at risk

Overdiagnosis

results in unnecessary and often dangerous treatments to both patients

Usual imaging modalities must be considered with developing fetusSlide5

Pulmonary Embolism

Higher risk 2/2

Virchows

triad

Hypercoagulability

Vascular damageVenous stasisDVT occurs approximately 3x more frequently than PEDVT occurs on left leg in 85% of casesLikely due to compression of iliac vein by iliac artery and gravid uterusIsolated pelvic DVT is also much more common in parturientsSlide6

Pulmonary Embolism

ACOG guidelines to diagnosis

Diagnosis

often

difficult

D-Dimer unreliable in pregnant patientsRisk of radiation exposure in pregnancy must be consideredSlide7

Treatment

LMWH is treatment of choice in early pregnancy

Can be given as outpatient

Do not cross placenta and are is not secreted in breastmilk

1mg/kg q12

IV unfractionated heparin preferred near delivery and in renal failureAble to reverse urgently if neededAlso does not cross placenta or go into breastmilkBolus 80u/kg followed by 18u/kg/h, titrated to achieve therapeutic aPTT If SC initial dose is 17,500 units then titrated to aPTTThrombolytic drugs appropriate in hemodynamically unstable or hypoxicFetal loss vs. maternal deathWarfarin teratogenic and generally contraindicated in pregnant patientSlide8

Venous Air Embolism

Entrapment of air or medical gases into venous system causing symptoms and signs of pulmonary vessel obstruction

1% of maternal deaths

Incidence varies WIDELY depending on the source

Depends on surgical position, diagnostic tools Slide9
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Pathophysiology

Vascular access and gradient between injury site and right heart must be present for VAE to occur

Determined by rate, volume, duration, patient position, type of

gas

Pulmonary vessels can filter most air emboli from venous

circulationLarger emboli can cause a variety of symptomsSlide11

Risk Factors VAE

Trendelenburg position

Placental abruption

Placenta

previa

Exteriorization of uterusManual placental extractionSevere preeclampsiaAntepartum hemorrhagehypovolemiaSlide12

Diagnosis

Know clinical signs and symptoms

May manifest as chest tightness or short breath with or without hypotension or decreased oxygen saturation in conscious patients

Variety of

diagnositic

toolsSlide13

Treatment

Inform Surgeon

Adequate hydration

Prevent further gas entry

Flood surgical field

Remove origin of gas entryIncrease right atrial pressure and trap air in right atriumReverse Trendelenburg when possibleLeft lateral recumbent positionDiscontinue N2O and ventilate with 100% oxygenAttempt to aspirate air through central line when appropriateResuscitateFluid administrationInotropes, vasopressor, pulmonary vasodilatorsCPR if necessaryHyperbaric oxygen when appropriateSlide14

Amniotic fluid embolism

5.7% of pregnancy related deaths in United States in 2011-12

Poorly understood

Diagnosis traditionally made at autopsy when fetal squamous cells are found in pulmonary circulation

Diagnosis of

exclusionMortality of AFE approaches 80%50% die within the first hour of onset of symotomsSlide15

AFE Pathophysiology

Theorized that amniotic fluid and cells enter circulation and trigger anaphylactic reaction

Fetal material not always found in patients with AFE and fetal material found in patients who did not trigger anaphylaxis

Currently believed that fluid or some other substance enters maternal circulation and triggers anaphylactic reaction OR activates complement cascade OR both.

Occurs in 2 phases

1. pulmonary artery vasospasm with pulmonary hypertension and elevated right ventricular pressure which causes hypoxia. Hypoxia causes myocardial and pulmonary capillary damage, left heart failure and ARDS.2. Those who survive phase 1 have hemorrhagic phase with massive hemorrhage with uterine atony and DIC; however, fatal consumptive coagulopathy may be the initial presentationSlide16

AFE risk factors

Multiparity

Advanced maternal age

Male fetus

Trauma

AbruptionPreviaNon-Hispanic black women have more than 2x risk of AFEWomen with cerebrovascular disease have 25x riskCardiac disease have 70x risk!Slide17

Treatment

Supportive

Early resuscitation

Pulmonary edema common – fluid input and output must be closely monitored

Left heart failure treated with

ionotropesCase reports show successful outcomes with hemodialysis with plasmapheresis and ECMO with intra-aortic balloon pumpDIC treated with blood components. Consider activated factor VIIa for severe hemorrhage2 cases report success with bilateral uterine artery embolization Slide18

References

Panting-Kemp A, Geller SE, Nguyen T, Simonson L,

Nuwayhid

B, Castro L. Maternal deaths in an urban perinatal network,

1992-1998

. Am J Obstet Gynecol. 2000;183:1207-1212.Chan WS, Ray JG, Murray S, Coady GE, Coates G, Ginsberg JS. Suspected pulmonary embolism in pregnancy: clinical presentation, results of lung scanning, and subsequent maternal and pediatric outcomes. Arch Intern Med. 2002;162:1170-1175. Einstein AJ, Henzlova MJ, Rajagopalan S. Estimating risk of cancer associated with radiation exposure from 64-slice computed tomography coronary angiography. JAMA. 2007;298:317-323http://www.acog.org/~/media/Districts/District%20VIII/PulmonaryEmbolismPregnancy.pdf?dmc=1&ts=20140525T0200225053Kim, Chang Seok et al. “Venous Air Embolism during Surgery, Especially Cesarean Delivery.” 

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