A randomised double‐blind study of interpleural analgesia after cholecystectomy

Abstract

Summary Continuous interpleural analgesia provided by 4 hourly injectionsPain relief after unilateral thoraco-abdominal operations may be provided by the administration of bupivacaine into the pleural space.'" A duration up to 27 hours after a single injection of 0.5% bupivacaine 20 ml with adrenaline 5 pg/ml has been reported,l but recent studies suggest that analgesia is usually shorter-lived.4.s In our experience, analgesia invariably wears off within 5 hours of administration of the above dose, although 4 hours of pain relief is consistently achieved. Patients who require little or no opioid supplementation may experience extremely painful episodes because the effect of the local anaesthetic wears off rapidly and there is no background analgesia. This intermittent absence of pain relief tends to exaggerate the efficacy of the technique and the possible beneficial effects on respiratory function.2S6 It needs to be shown that interpleural analgesia has advantages compared to current regimens before it is adopted for widespread clinical use. The plasma concentrations of bupivacaine attained when interpleural block is maintained using repeated bolus injections of local anaesthetic for prolonged periods remain to be determined.The aims of this study were to compare interpleural analgesia to placebo in a randomised, double-blind manner and assess whether a combined interpleural and systemic opioid technique provides better pain relief than opioid alone. Local anaesthetic blockade was maintained, and episodes of severe pain were avoided. We examined the effects of interpleural analgesia on respiratory function and measured the plasma concentrations of bupivacaine that may be expected when an intermittent bolus technique is used in an optimal fashion. MethodsTwenty patients (aged 24-70 years, ASA 1 or 2), undergoing cholecystectomy were admitted to the study, which was approved by the local ethics committee. All patients received instruction before operation in the use of the Cardiff Palliator and visual analogue scales for scoring pain. Baseline measurements of FEV,, FVC and the FEV,/ FVC ratio were made with the patient in the sitting position using a wedge spirometer (Vitalograph).

Interpleural analgesia for attenuation of postoperative pain after hepatic resection*

“…Numerous studies demonstrate an acceptable safety profile with bupivacaine administered via the interpleural route [6, 8, 12–14, 16, 19]. In our study we used a conservative dosing regime and found no reported symptoms consistent with local anaesthetic toxicity.…”

“…Whilst there are sufficient patients to detect a clinically important difference in the primary endpoint, we are unable to detect the true incidence of complications from interpleural analgesia due to the relatively small sample size. Plasma levo‐bupivacaine levels were not evaluated as they have been well reported in numerous other studies [1, 6, 8, 12, 13, 16, 19, 26]. Although we found no reported symptoms of local anaesthetic toxicity, it is possible that plasma levels may have demonstrated concentrations above the accepted safe range.…”

“…Derangements in coagulation after hepatic resection have favoured systemic multimodal analgesia in preference to neuraxial techniques as the preferred method for effective delivery of postoperative analgesia in many institutions. Several studies report the use of interpleural local anaesthetic solutions as an effective technique for analgesia following unilateral upper abdominal surgery [1–19]; however, it is unknown if interpleural analgesia is effective for patients receiving a right subcostal surgical incision with a midline abdominal incision extension (reverse‐L incision), a commonly used surgical incision for patients undergoing this procedure. For patients undergoing hepatic resection we think that interpleural analgesia is a beneficial analgesic adjunct to systemic morphine patient controlled analgesia.…”

Interpleural block – part 2

“…Interpleural block has been most extensively studied for postoperative analgesia in patients undergoing unilateral subcostal and flank incisions, i.e. open cholecystectomy [1][2][3][4][5][6][7][8][9][10][11], renal surgery [1,[12][13][14] and unilateral breast surgery [1,12,15,16]. The dosing regimens used have been dealt with in our first review [17].…”

“…Tumour invasion of the brachial plexus [68] Unilateral breast surgery [1,12,15,16] Open cholecystectomy [1][2][3][4][5][6][7][8][9][10][11] Pain of acute herpes zoster and post herpetic neuralgia [64][65][66][67] Needle localisation and breast biopsysole anaesthetic [15] Laparoscopic cholecystectomy [25,26] Chronic regional pain syndromes of the upper limb [36,61,63] Thoracotomy [42,43,45,[48][49][50][51] Renal surgery [1,[12][13][14] Upper limb ischaemia [62] Chest drain [108,109] Abdominal surgery (bilateral blocks) [55,56] Cardiac surgery [53,54] Percutaneous hepatic and biliary drainage procedures [27][28][29] Thoracic sympathectomy…”