Post-Cardiac Arrest Care and Oxygenation Targets
Oxygen and ventilation targets
After return of spontaneous circulation, titrate oxygen to the lowest level that keeps saturation in the normal range - approximately 92% to 98% - and wean the fraction of inspired oxygen as soon as possible. Both hypoxia and hyperoxia harm the post-arrest brain. Target normocapnia with a PaCO2 of about 35–45 mm Hg; hyperventilation causes cerebral vasoconstriction and hypocapnia, while hypoventilation causes hypercapnia and acidosis.
Hemodynamics and temperature
Support blood pressure to a mean arterial pressure of at least 65 mm Hg, using fluids and vasopressors as needed. Use targeted temperature management for comatose patients after arrest: maintain a constant temperature between 32°C and 36°C for at least 24 hours, or actively prevent fever, then rewarm slowly. Treat seizures, check and correct glucose, and obtain a 12-lead ECG to look for ST-elevation myocardial infarction, which may warrant immediate coronary intervention.
Prognostication
Neurologic prognostication should not be performed earlier than about 72 hours after return of circulation, and should use multiple modalities - clinical exam, electrophysiology, imaging, biomarkers - because sedation and hypothermia confound the examination.
Traps
Common distractors: "continue 100% oxygen until awake," "hyperventilate to reduce cerebral edema," "prognosticate at 24 hours," and routine sodium bicarbonate. Also watch for answers that ignore the possibility of an acute coronary occlusion as the cause of arrest.
Rule of thumb
Treat the oxygen saturation like a drug dose: too little and too much both injure the brain - aim for the 92–98% window and a normal CO2.