Intra-operative and post-operative hypercapnia leading to delayed respiratory failure associated with transanal endoscopic microsurgery under general anaesthesia.

We present an unusual case of hypercapnia and surgical emphysema during transanal endoscopic microsurgery, which led to delayed post-operative ventilatory failure. The hypercapnia and surgical emphysema were secondary to rectal insufflation with carbon dioxide used to facilitate visualization and resection of a rectal tumour. Despite a return to wakefulness after surgery, the patient's level of consciousness deteriorated in the recovery area as a result of hypercapnia. The PaCO2 rose to 16.8 kPa because of absorption of carbon dioxide from the surgical emphysema. On close examination, surgical emphysema was identified in unusual areas, including the anterior abdominal wall, both loins, both groins and the left thigh. Reventilation was required until these unusual carbon dioxide stores had dissipated. We discuss the need for prolonged post-operative vigilance in patients with surgical emphysema secondary to carbon dioxide insufflation, and the risk of delayed ventilatory failure.