Catastrophic presentation of venous air embolism in supine position

Introduction: Air embolism is a common complication during neurosurgery especially in sitting position with incidence of clinically significant venous air embolism around 25-40% followed by prone position. Risk of air embolism is usually neglected in supine position because of very low incidence. We report a case of massive air embolism in supine position during decompressive craniotomy for MCA territory infarct. Case Summary: 60 year male patient weighing 70 kg presented for decompressive craniotomy for MCA territory infarct. Patient was known hypertensive since 10 years taking amlodepin 5 mg and presented with GTCS, headache, vomiting since 2 days. Preoperative investigations were within normal limits. Patient was induced with propofol, morphine and vecuronium. Patient developed massive venous air embolism after bone flap elevation which was detected by fall in EtCO2 more than 2 mmhg within 3 minutes followed by haemodynamic instability. Surgeon was informed about the possibility of air embolism, N2O was shut off, patient was ventilated with 100% of O2, surgical field flooded with saline. Central line (rt subclavian) was inserted and around 20 cc air was aspirated. Associated hypotension was managed with IV fluid boluses, vasopressor and ionotrops and shifted to neurosurgery ICU. Conclusion: Risk of venous air embolism during craniotomy requires high index of suspicion even in supine position though the incidence is very less.