Role of intrathecal nalbuphine on prevention of postspinal shivering after knee arthroscopy

BackgroundShivering associated with spinal anesthesia is a common and uncomfortable problem and may interfere with monitoring, oxygen consumption and carbon dioxide production. The aim of the study was to evaluate the effect of intrathecal nalbuphine on the prevention of shivering during spinal anesthesia in patients undergoing knee arthroscopy.Methods60 patients (ASA physical status I or II) scheduled for knee arthroscopy under spinal anesthesia were randomly assigned to one of two equal groups: Group C (control group, n = 30) receiving 2.5 ml of 0.5% bupivacaine during spinal anesthesia; and Group N patients (nalbuphine group, n = 30) receiving 2.5 ml of a mixture of 400 μg nalbuphine plus 0.5% bupivacaine during spinal anesthesia. Before commencing regional anesthesia, standard monitoring was established and patients were given intravenous 15 ml/kg/h of crystalloid solution (at room temperature 23–25 °C). All operations were performed in the same operating room which maintained at a constant temperature of 23–25 °C and no means of active warming were used. Mean arterial blood pressure (MAP), heart rate (HR), arterial oxygen saturation (SPO2), core (tympanic) temperature, the incidence and severity of shivering were all determined and recorded at baseline and every 10 min after anesthesia till end of surgery.ResultsShivering was observed in 19 patients (63.3%) in control group and 7 patients in nalbuphine group (23.3%) with significant difference between the two groups (P = 0.004) and significant difference in intensity of shivering and core temperature (P < 0.001). No significant statistical difference was observed as regards hemodynamic parameters and oxygen saturation between the two groups.ConclusionIntrathecal nalbuphine is an effective and safe method to prevent shivering during spinal anesthesia in patients undergoing knee arthroscopy.