Postoperative Complications
Core concepts
Organize complications by system and timing. Respiratory: hypoxemia, hypoventilation, aspiration, atelectasis, pneumonia, pulmonary embolism. Cardiovascular: hypotension, hypertension, arrhythmias, myocardial ischemia, deep vein thrombosis. Neurologic: delirium, stroke, nerve injury, residual blockade. Surgical: bleeding, infection, anastomotic leak, compartment syndrome. Metabolic: electrolyte disturbances, hyperglycemia, malignant hyperthermia in the immediate period.
Recognize red flags: fever with tachycardia and hypotension suggests sepsis; sudden dyspnea and hypoxemia suggest embolism or pneumothorax; oliguria and hypotension suggest hypovolemia or renal injury; altered mental status suggests hypoxia, hypercapnia, delirium, or stroke.
Malignant hyperthermia: triggered by volatile anesthetics and succinylcholine; presents with rising end-tidal CO2, rigidity, hyperthermia, acidosis, and hyperkalemia. Treat with dantrolene, cooling, and supportive care.
Traps
- Attributing postoperative hypoxemia solely to atelectasis and missing embolism or opioid-induced hypoventilation.
- Missing early sepsis because of normal temperature.
- Confusing delirium with residual anesthesia without evaluating oxygenation and glucose.
- Delaying dantrolene in suspected malignant hyperthermia.
Rule of thumb
Use a systematic ABC approach and look for the most dangerous explanation first. New fever plus hypotension is sepsis until proven otherwise; sudden respiratory deterioration is embolism or pneumothorax until excluded.
Worked example
In recovery, a patient develops rising end-tidal CO2, muscle rigidity, and tachycardia after volatile anesthesia. Stop triggering agents, call for help, give dantrolene, cool the patient, and treat hyperkalemia and acidosis.