Pulmonary oedema in a patient undergoing vitreo-retinal surgery under peribulbar block

A 42-year-old diabetic and hypertensive male with good effort tolerance was administered peribulbar block for vitreo-retinal surgery. Ten millilitres of an equal mixture of 2% lignocaine and 0.5% bupivacaine was administered for the block after ascertaining negative aspiration for blood. Inadequate akinesia of the eye necessitated further supplementation with 4 mL of local anaesthetic (LA) mixture. Thirty minutes later, the patient complained of uneasiness, respiratory distress and desaturated despite oxygen supplementation. He was found to be in pulmonary oedema. He subsequently developed a weak thready pulse, became unresponsive, apnoeic and had generalized tonic clonic convulsions. Immediately, atropine 0.6 mg, followed by midazolam, intubation, mechanical ventilation, morphine and furosemide, were administered intravenously. Spontaneous respiration returned in 20 minutes and he started responding to verbal commands 90 minutes later. He was weaned off the ventilator the next morning. There was no evidence of an ischemic myocardial event and non-contrast computerized tomography scan of the head was normal. The reversible cardiorespiratory arrest, associated convulsions and loss of consciousness were suggestive of LA toxicity. Pulmonary oedema manifesting as respiratory distress and desaturation can be the initial manifestation of LA toxicity in patients with pre-existing cardiovascular disease undergoing eye surgery under peribulbar block.