Coma and seizures due to gas embolus following extubation
We report a 27 year old man who developed coma and focal seizures due to cerebral gas embolus during extubation in ICU. Recent open pyeloplasty had been complicated by post-operative haemorrhage and difficult intubation (Grade 2-3 laryngoscopoic assessment). Prior to extubation the patient was alert and interactive with no neurological deficits. As a precaution, a Cook airway exchange catheter was used and inadvertently advanced during extubation. The patient suddenly lost consciousness, began sweating profusely, his teeth clenched around the catheter and airway protection was compromised. Rapid re-intubation was achieved by ‘rail-roading’ the ETT over the catheter. Oxygen saturation remained >95% throughout the event. However, the patient remained comatose despite the administration of flumazenil, naloxone and phenytoin. He was tachycardic, had subcutaneous emphysema and subsequently developed left limb focal motor seizures with secondary generalisation. CT scans showed diffuse cerebral oedema. With conservative management the patient improved over several weeks. On discharge there was a mild left hemiparesis with some cognitive dysfunction and disinhibiton. Convalescent MRI showed mild to moderate diffuse atrophy and right frontal and periventricular hyperintense foci.
Conclusion: Cerebral gas embolism is an unusual cause of sudden unconsciousness, seizures and focal neurological deficits in a variety of iatrogenic contexts. There should be a high index of suspicion of this diagnosis in the context of barotrauma and lung injury acquired during extubation, bronchoscopy or positive pressure ventilation.