Increasing numbers of obese (BMI > 30), morbidly obese (BMI > 40) and super obese (BMI > 50) patients are presenting for gynaecological laparoscopic surgery. Evidence regarding management and outcomes is unfortunately almost non-existent. It is possible to extrapolate from studies in laparoscopic bariatric surgery, although even here the evidence is limited and may be falsely reassuring because of the greater challenges of the Trendelenburg position compared with reverse Trendelenburg.

It is important to distinguish the challenges due to obesity per se from those due to the co-morbidities which are commoner with increasing obesity (obstructive sleep apnoea, type 2 diabetes and cardiovascular disease in particular) as well as the longer duration of surgery inevitably associated with operating on obese patients.

Obesity brings very practical challenges for the anaesthetist. Venous access is more difficult, sometimes necessitating ultrasound-guided cannulation. Similarly, airway management may require special techniques, including video-laryngoscopy or even fibreoptic intubation. Patient handling and positioning pose risks for all staff as well as for the patient.

Intraoperatively, the management of pulmonary gas exchange is the biggest anaesthetic challenge. Most research has focused on CO₂  uptake from the pneumoperitoneum and its respiratory elimination. Evidence suggests that these changes are the same in obese and non-obese patients. In any case, concerns around a temporarily elevated arterial CO₂ have been greatly overstated. It is far safer to accept moderate hypercarbia rather than risk pulmonary barotrauma with grossly elevated inspiratory pressures. Maintenance of adequate oxygenation, on the other hand, is much more problematic with increasing obesity. An occasional pause in the surgery, with release of the pneumoperitoneum and head-up tilt, will produce a period of improved oxygenation, allowing surgery to then continue; rarely, laparoscopic surgery must be abandoned.

Suitability of obese patients for ambulatory (day case) surgery is an important question. Below a BMI of 50, limited evidence suggests that raised BMI alone is not an independent risk factor for postoperative complications, so usual criteria of suitability should apply. But once BMI exceeds 50 (super obese), increasing risk of postoperative complications as well as the practicalities of safe management mean that overnight admission to a specialist facility is almost certainly advisable.