The Pregnant ICU Patient

• Pregnancy physiology: ↓SVR so BP falls, ↑plasma volume causing dilutional anemia, compensated respiratory alkalosis, and aortocaval compression after 20 wk (use LEFT TILT).
• Begin perimortem cesarean by 4 min of arrest and deliver by 5 min when gestation is >20–24 wk; it improves BOTH resuscitations.
• Amniotic fluid embolism care is supportive with aggressive correction of coagulopathy.
• Drug safety in pregnancy differs, so check before imaging or medications, and monitor the fetus from ≥24 wk.

Differential Diagnosis of Respiratory Distress

• Symptoms of respiratory distress → physical examination
• No air movement → DDx: asthma · pneumothorax
• Wheezing → DDx: asthma · pulmonary edema · anaphylaxis
• Rales/crackles → DDx: pulmonary edema · pneumonia · ARDS · aspiration · pleural effusion · atelectasis · bronchitis
• Normal examination → observe · consider pulmonary embolus

Asthma

• Symptoms: wheezing, coughing, dyspnea, and chest tightness
• Severity assessment
• FEV₁ >50%: O₂ targeting SaO₂ ≥90–95 · inhaled β₂ agonist by nebs or MDI · ± steroids
• FEV₁ <50%: O₂ targeting SaO₂ ≥90–95 · inhaled β₂ agonist nebs · steroids
• Signs of respiratory failure: severe symptoms · poor response to treatment · drowsiness · altered mental status/confusion · PCO₂ >40 → ADMIT TO HOSPITAL: IV or PO steroids · inhaled β₂ agonist nebs · titrate O₂ to SaO₂ ≥95%
• Re-evaluate in 1 hour
• Response at 1 hour?
• FEV₁ ≥70 (mild exacerbation) — good response → discharge to home with follow-up
• FEV₁ 50–70% (moderate exacerbation) → repeat the modalities → respond well: discharge with follow-up; respond poorly: admit to hospital
• FEV₁ <50% (severe exacerbation) → ADMIT TO ICU: nebulized β₂ agonist · IV steroids · intubate and ventilate or 100% by nonrebreather mask

Amniotic Fluid Embolus

• Clinical presentation: woman in labor, s/p cesarean, dilation and evacuation, or postpartum with sudden: acute hypoxia · acute hypotension or cardiac arrest · then acute fetal hypoxia and consumptive coagulopathy. DDx: anesthetic complications · medication reaction · myocardial infarction · eclampsia · placental abruption · postpartum hemorrhage · pulmonary embolus
• Initial evaluation: ABG · CBC, coagulation studies · type and cross · CXR · EKG
• Treatment is generally supportive; maternal death is common even with aggressive care
• ACUTE HYPOXIA: maintain oxygenation · continuous fetal monitoring
• HYPOTENSION: expand volume · pressors · inotropes · continuous fetal monitoring · CPR if indicated
• CONSUMPTIVE COAGULOPATHY: fresh-frozen plasma · PRBC · cryoprecipitate · platelets (fibrinogen normally varies by trimester: 300–600 mg/dL)
• MATERNAL CARDIAC ARREST — if fetus in utero: perimortem cesarean delivery

Differential Diagnosis of Pulmonary Edema in Pregnancy

• Pulmonary edema diagnosed by physical examination and CXR
• Calculate intake and output — positive intake?
• Treat for fluid overload
• Elevated BPs with proteinuria?
• Treat for severe preeclampsia and possible delivery
• Abnormal echocardiogram?
• EF <45%: treat for peripartum cardiomyopathy and possible delivery
• Patient on tocolytic therapy?
• Stop the tocolytic agent · semi-fowler position · give O₂ via nonrebreather or with CPAP · intubation may be needed · furosemide: 20–40 mg IV, repeat if necessary · strict input and output and limit intravenous fluid infusion · no resolution of pulmonary edema within 12–24 hours: consider alternate causes of respiratory distress

Pulmonary Embolism (PE)

• Clinical suspicion of PE (in pregnancy)
• Lower extremity Dopplers → DVT: anticoagulate
• Lower extremity Dopplers negative?
• EKG, CXR, ABG
• CXR result?
• Abnormal CXR → CTA
• CTA result?
• PE → therapeutic anticoagulation
• Negative → observe clinically, rule out other pathology
• Normal CXR → VQ scan
• VQ scan result?
• High probability → therapeutic anticoagulation
• Low probability → observe clinically, rule out other pathology · indeterminate → CTA

Acute Kidney Injury in Pregnancy

• Dx: acute kidney injury in pregnancy — calculate FENa
• PRERENAL (FENa <1): acute blood loss from abruption or hemorrhage → address the source of bleeding, IVF, blood products · hyperemesis gravidarum → IVF, B6, antiemetics, electrolyte replacement, ± steroids
• POSTRENAL (FENa >4): kidney stones (diagnose by renal U/S: flank pain, hematuria) → expectant cystoscopy ± stents
• INTRARENAL or ATN (FENa >1) — differential:
• PREECLAMPSIA (proteinuria, HTN): magnesium sulfate · deliver based on gestational age ± corticosteroids for fetal lung maturity
• HELLP SYNDROME (thrombocytopenia, HTN, proteinuria, ↑AST, ↑bilirubin, ↑LDH, normal glucose): magnesium sulfate · deliver based on gestational age ± corticosteroids for fetal lung maturity
• PYELONEPHRITIS (fever, CVA tenderness, positive urine culture): antipyretics · initiate ceftriaxone
• TTP/HUS (hemolytic anemia: ↑bilirubin, ↑LDH, schistocytes on smear · severe thrombocytopenia — platelets <100,000, usually <20,000 · fever · neurologic abnormalities · renal dysfunction · ± proteinuria, ± HTN): plasma exchange each day until platelets normalize ± IV or PO steroids
• ACUTE FATTY LIVER OF PREGNANCY (↑ammonia · ↑LDH · ↓glucose · ↑AST · ↓fibrinogen, ↓antithrombin · ↑PT/INR · ↑direct bilirubin · ±HTN, ±proteinuria, ±thrombocytopenia): maternal stabilization · correct coagulopathy · delivery · ± liver biopsy

Managing Shock in Pregnancy

• Concern for shock (in pregnancy)
• Clinical assessment: vital signs · fetal status · urine output · EBL if postpartum · IVF/blood products · medications
• Labs: CBC · PT/PTT, fibrinogen · electrolytes, liver function tests · EKG · arterial blood gas
• If febrile without known source, add: CXR · UA with culture · blood cultures
• Intensive monitoring: Foley catheter · continuous pulse oxygen · telemetry · invasive cardiac monitoring
• Treatment appropriate to suspected etiology

Differential Diagnosis of Shock in Pregnancy

• Clinical diagnosis of shock (in pregnancy) — categorize
• HYPOVOLEMIC/HEMORRHAGIC: placental abruption · postpartum hemorrhage — atony, retained products, laceration, placental site abnormality, uterine inversion
• DISTRIBUTIVE/SEPTIC: chorioamnionitis · pyelonephritis · endometritis · pneumonia · wound or episiotomy infection · septic abortion · necrotizing fasciitis
• CARDIOGENIC: cardiomyopathy · pulmonary embolism · severe valvular disease · myocardial infarction
• DISTRIBUTIVE/ANAPHYLACTIC: medication reaction · amniotic fluid embolism · environmental exposure