Airway and respiratory complications during anaesthesia and associated with peri-operative cardiac arrest as reported to the 7th National Audit Project of the Royal College of Anaesthetists

The 7th National Audit Project (NAP7) of the Royal College of Anaesthetists studied complications of the airway and respiratory system during anaesthesia care including peri-operative cardiac arrest. Among 24,721 surveyed cases, airway and respiratory complications occurred commonly (n = 421 and n = 264, respectively). The most common airway complications were: laryngospasm (157, 37%); airway failure (125, 30%); and aspiration (27, 6%). Emergency front of neck airway was rare (1 in 8370, 95%CI 1 in 2296-30,519). The most common respiratory complications were: severe ventilation difficulty (97, 37%); hyper/hypocapnia (63, 24%); and hypoxaemia (62, 23%). Among 881 reports to NAP7 and 358 deaths, airway and respiratory complications accounted for 113 (13%) peri-operative cardiac arrests and 32 (9%) deaths, with hypoxaemia as the most common primary cause. Airway and respiratory cases had higher and lower survival rates than other causes of cardiac arrest, respectively. Patients with obesity, young children (particularly infants) and out-of-hours care were overrepresented in reports. There were six cases of unrecognised oesophageal intubation with three resulting in cardiac arrest. Of these cases, failure to correctly interpret capnography was a recurrent theme. Cases of emergency front of neck airway (6, approximately 1 in 450,000) and pulmonary aspiration (11, approximately 1 in 25,000) leading to cardiac arrest were rare. Overall, these data, while distinct from the 4th National Audit Project, suggest that airway management is likely to have become safer in the last decade, despite the surgical population having become more challenging for anaesthetists.