Reducing cardiovascular responses to laryngoscopy and tracheal intubation: a comparison of equipotent doses of tramadol, nalbuphine and pethidine, with placebo.

The stress response to tracheal intubation may be obtunded by opioids given with induction of anesthesia. Tramadol is an opioid acting on mu-receptors and the monoaminergic pain modulating systems. This study examined vasomotor responses to tracheal intubation after equipotent doses of tramadol, nalbuphine and pethidine (3.0, 0.3 mg/kg(-1), and 1.5 mg/kg(-1), respectively), and placebo, given prior to induction of anesthesia in 118 healthy patients. Premedication and induction of anesthesia were standardized. Recordings of HR and SAP were made prior and subsequent to induction of anesthesia, and at 1, 3, 5 and 7 minutes after tracheal intubation. Prior to laryngoscopy and intubation, HR increased in all groups (p < or = 01, all comparisons), but least so after nalbuphine, whilst SAP remained unchanged after placebo, tramadol and pethidine, but fell after nalbuphine (p < 0.025). Maximum increases in HR (p < or = 0.005, all comparisons) and SAP (p < or = 0.02, all comparisons) occurred one minute after intubation. Maximum HR after placebo (108 SD 15 bpm), tramadol (107 SD 20 bpm), pethidine (113 SD 16 bpm) and nalbuphine (110 SD 26 bpm) was similar; with placebo HR remained faster than baseline until the seventh minute but had returned to baseline by the fifth minute with the opioids. Maximum SAP with tramadol (151 SD 26 mmHg) was similar to that with placebo (157 SD 20 mmHg), but was greater than after pethidine (136 SD 27 mmHg; p < 0.05) and nalbuphine (135 SD 19 mmHg; p < 0.02). With each test drug SAP returned to baseline by the third minute. It is concluded that, in these doses, 1) tramadol does not attenuate the chronotropic nor the inotropic response to tracheal intubation, and 2) pethidine and nalbuphine reduce only the inotropic response to airway instrumentation.

Analgesia for adenotonsillectomy in children and young adults: a comparison of tramadol, pethidine and nalbuphine.

A prospective, double-blind, randomized, controlled study was undertaken to compare the perioperative analgesic and recovery characteristics of equipotent doses of tramadol, pethidine and nalbuphine (3.0 mg kg-1, 1.5 mg kg-1 and 0.3 mg kg-1 respectively) with placebo (saline 0.02 ml kg-1) given at induction of anaesthesia in 152 ASA 1 children and young adults undergoing tonsillo-adenoidectomy. Premedication (temazepam and diclofenac), induction and maintenance of anaesthesia (thiopentone, atracurium, nitrous oxide and isoflurane), with controlled ventilation, were standardized. Variables monitored were heart rate (HR) and systolic arterial pressure (SAP) during surgery, time to recovery of spontaneous respiration at the termination of anaesthesia and restlessness, time to awakening, sedation and emesis in the recovery unit. Increases in HR or SAP > 33% of baseline during surgery were treated with esmolol 2.0 mg kg-1 intravenously (i.v.) and restlessness during recovery was treated with the same opioid i.v. given with an aesthesia, or pethidine i.v. in the placebo group. With placebo, there was a high requirement for esmolol during surgery and for pethidine in the recovery ward. Tramadol did not reduce the rate of intra-operative treatment with esmolol, but reduced the tramadol requirement during recovery (P < 0.05). Pethidine and nalbuphine reduced the intra-operative esmolol requirement more significantly (P < 0.025 and P < 0.005 respectively) and the need for treatment during recovery with opioids (P < 0.005 each). The time to recovery of spontaneous respiration at the end of anaesthesia was only delayed by pethidine. Other recovery variables were similar, except that restlessness-pain scores were reduced by tramadol (P < 0.02), pethidine (P < 0.005) and nalbuphine (P < 0.005). These results suggest that pethidine 1.5 mg kg-1 and nalbuphine 0.3 mg kg-1 given with induction of anaesthesia provide better analgesia during and after tonsillo-adenoidectomy than does tramadol 3.0 mg kg-1. The delay to recovery of spontaneous respiration with pethidine suggests a greater safety profile of nalbuphine and tramadol.