How can I manage anaesthesia in obese patients?

The obese patient is at risk of perioperative complications including difficult airway access (intubation, difficult or impossible ventilation), and postextubation acute respiratory failure due to the formation of atelectases or to airway obstruction. The association of obstructive sleep apnoea syndrome (OSA) with obesity is very common, and induces a high risk of per and postoperative complications. Preoperative OSA screening is crucial in the obese patient, as well as its specific management: use of continuous positive pre-, per- and postoperative pressure. For any obese patient, the implementation of difficult intubation protocols and the use of protective ventilation (low tidal volume 6-8mL/kg of ideal body weight, moderate positive end-expiratory pressure of 10cmH20, recruitment manoeuvres in absence of contra-indications), with morphine sparing and semi-seated positioning as much as possible are recommended, associated with a close postoperative monitoring. The dosage of anaesthetic drugs is usually based on the ideal body weight or the adjusted body weight and then titrated, except for succinylcholine that is dosed according to the total body weight. Monitoring of neuromuscular blockers should be used where appropriate, as well as monitoring of the depth of anaesthesia, especially when total intravenous anaesthesia is used in association with neuromuscular blockers. The occurrence of intraoperative awareness is indeed more frequent in the obese patient than in the non-obese patient. Appropriate prophylaxis against venous thromboembolism and early mobilisation are recommended, if possible included in an early rehabilitation protocol, to further reduce postoperative complications.