Prospective Double Blind Randomized Controlled Trial of the Use of Intraperitoneal Nebulised Local Anaesthetic

Pain post laparoscopic procedures can be divided into access related, operation site and distension related. The access type can be attenuated by the use of sub dermal infiltration of local anaesthetic and rarely causes significant discomfort. It has been advocated that placement of a peritoneal gas drain significantly reduces postoperative pain particularly referred to the shoulder tip. Realistically, however, if attention is paid to expelling the residual gas at the end of the procedure this complication is rarely problematic. Operative site pain however is more difficult to manage. In limited gynaecological procedures it has been shown that local installation of local anaesthetic decreased the analgesic requirement of patients post operatively. These observations would not be as transferable to more extensive colorectal or solid organ surgery as the amount of local anaesthesia required would be toxic to the patient. Use of the nebuliser, however maybe able to alleviate pain by efficiently using the dosage required.

This is a prospective randomised double blind trial. Sixty patients will be allocated randomly between three groups, 20 patients in each group:

1. Control group
2. Nebulised intraperitoneal local anaesthetic (Bupivacaine 0.25%, 3mg/Kg)
3. Nebulised intraperitoneal normal saline Ward staff will be blinded to which group the patients are in. All patients undergoing laparoscopic cholecystectomy who have given written, informed consent are eligible for inclusion. Patients with local anaesthetics allergy and patients whom pain evaluation is considered unreliable due to chronic opiate use or neurological diseases are excluded.

No pre-medication is to be given and a standardised anaesthetic technique is to be employed for all patients.

Standard 4 ports technique for laparoscopic cholecystectomy will be used with intraperitoneal pressure between 12-14 mmHg. This will be achieved using CO2 as the insufflation gas.