I: Intraperitoneal administration of analgesia: is this practice of any utility?

Intraperitoneal administration of analgesia: is this practice of any utility? Local anaesthetic techniques are part of the multimodal approach to postoperative pain management. 1 This involves the use of opioids, non-steroidal anti-in¯ammatory drugs (NSAIDs) 2 , paracetamol 3 and local anaesthetics. 4 The purpose of this editorial is to review whether or not instillation of local anaesthetics into the peritoneal cavity is a worthwhile modality in routine clinical practice during some intra-abdominal procedures. Data from a nationwide survey in the UK of anaesthesia for gynaecological laparoscopy revealed that local anaesthetic solutions are administered commonly, particularly into the wound and the peritoneal cavity. 5 For this type of ambulatory surgery and anaesthesia, the main advantage of using local anaesthetics is that they do not have the adverse effects of opioids, which may delay recovery and discharge from hospital. These effects include postoperative nausea, sedation, 2 impairment of return of gastrointestinal motility, and pruritis. In addition, time to return of bowel function in the postoperative period may be reduced when the use of opioids is obviated by administering local anaesthetics. 6 Although NSAIDs provide morphine-sparing effects 2 , they do not appear, on their own, to provide suf®ciently reliable postoperative analgesia for minimally invasive laparoscopic surgery. 7 In addition, they have the disadvantage that they may cause gastric irritation in addition to impairing platelet and renal function. In the perioperative period, many patients are at risk of these problems because of enforced starvation, dehydration and tissue trauma. Additional methods of analgesia are thus necessary. Local anaesthetics have been administered into the peritoneal cavity during minimally invasive procedures, such as laparoscopic cholecystectomy and gynaecological laparoscopy for sterilization and diagnosis, 8 in addition to open abdominal procedures, such as total abdominal hysterectomy. The rationale for this route of administration is that the peritoneum is exposed to block of visceral nociceptive conduction, thereby providing an additional mechanism of analgesia. However, absorption from the large peritoneal surface may also occur, and this may be a further mechanism of analgesia. It has been shown after radical retropubic prostatectomy that i.v. lidocaine 1.5 mg kg ±1 bolus and 2±3 mg min ±1 infusion reduced morphine consumption and total pain scores signi®cantly compared with placebo. 6 These data are supported by a clinical trial in which i.v. lidocaine produced a concentration-dependent reduction in pain scores when the plasma concentration exceeded 1.5 mg ml ±1. 11 In addition, it has …