Prophylactic ketamine to prevent shivering in parturients undergoing Cesarean delivery during spinal anesthesia.

STUDY OBJECTIVE: To compare the efficacy and safety of ketamine 0.25 mg/kg with ketamine 0.5 mg/kg to prevent shivering in patients undergoing Cesarean delivery. DESIGN: Prospective, randomized, double-blinded, placebo-controlled study. SETTING: Operating rooms and postoperative recovery rooms. PATIENTS: 120 ASA physical status 1 and 2 pregnant women scheduled for Cesarean delivery during spinal anesthesia. MEASUREMENTS: Patient characteristics, anesthetic and surgical details, Apgar scores at 1 and 5 minutes, and side effects of the study drugs were recorded. Heart rate, mean arterial pressure, oxygen saturation via pulse oximetry, tympanic temperature, severity of shivering, and degree of sedation were recorded before intrathecal injection and thereafter every 5 minutes. Patients were randomized to three groups: saline (Group C, n=30), intravenous (IV) ketamine 0.25 mg/kg (Group K-0.25, n=30), or IV ketamine 0.5 mg/kg (Group K-0.5, n=30). Grade 3 or 4 shivering was treated with IV meperidine 25 mg and the prophylaxis was regarded as ineffective. MAIN RESULTS: The number of shivering patients was significantly less in Group K-0.25 and in Group K-0.5 than in Group C (P = 0.001, P = 0.001, respectively). The tympanic temperature values of Group C were lower at all times of the study than in either ketamine group. Median sedation scores of Group K-0.5 were significantly higher than in Group K-0.25 or Group C at 10, 20, 30, and 40 minutes after spinal anesthesia. CONCLUSIONS: Prophylactic IV ketamine 0.25 mg/kg was as effective as IV ketamine 0.5 mg/kg in preventing shivering in patients undergoing Cesarean section during spinal anesthesia.

WITHDRAWN The analgesic effect of paracetamol when added to lidocaine for intravenous regional anesthesia.

Ahead of Print article withdrawn by publisher AIM: Intravenous regional anesthesia (IVRA) is frequently used in patients who will undergo upper extremity surgical operations for its ease of use, rapid effectiveness and short hospitalization period. Different drug combinations have been used to overcome some systemic adverse effects and to increase the postoperative analgesic effectiveness. In our study, we evaluated the effects of paracetamol (Perfalgan) when added to lidocaine for IVRA, looking specifically at tourniquet pain and postoperative pain. METHODS: Ninety patients undergoing elective hand surgery with IVRA were randomly assigned to three groups to receive either IV saline and C-IVRA with 0.5% lidocaine 3 mg/kg (control group, N=30), IV saline and IVRA with 0.5% lidocaine and 20 mL paracetamol (10 mg/cc) (P-IVRA group, N=30) or IV paracetamol and IVRA with 0.5% lidocaine (L-IV group, N=30). The following were measured: 1) sensory and motor block onset and recovery time, 2) tourniquet pain after tourniquet application and at 10, 20 and 30 min after tourniquet deflation, 3) the visual analog scale (VAS) scores of tourniquet pain at 30 min and 1, 2, 4, 6 and 24 h postoperatively, 4) the time to first analgesic requirement, 5) total analgesic consumption in 24 h and 6) side effects. RESULTS: Sensory and motor block onset and recovery times were similar in both groups. VAS scores of tourniquet pain were lower in group P-IRVA at 1, 2, 4, 6, and 24 h, postoperatively (P<0.01). Anesthesia quality, as determined by the anesthesiologist and surgeon, was similar in both groups. The time to the first postoperative analgesic request was 67.83±57.48 min in group C-IRVA and 93±80.79 min in group P-IRVA (P<0.05). Paracetamol consumption was significantly less in group P-IRVA (1.60± 1 [tablets]) when compared with group C-IRVA (2.45±0.9; P<0.05). CONCLUSIONS: Perfalgan as an adjunct to lidocaine improves postoperative analgesia in IVRA without adverse effects.

Perioperative anxiety and postoperative behavioural disturbances in children: comparison between induction techniques.

BACKGROUND AND OBJECTIVE: This study was designed to determine if subhypnotic propofol reduces postoperative behavioural disturbances in children undergoing sevoflurane induction compared with intravenous propofol induction for elective adenoidectomy and tonsillectomy. METHODS: Following Ethics Committee approval and parental informed consent, ASA I-II, 120 children (2-10 yr) were recruited. Parents were not allowed to accompany their child. Unpremedicated children were randomly allocated to groups receiving inhalation induction with sevoflurane, 2-2.5 mg kg-1 intravenous propofol induction or inhalation induction with sevoflurane followed by subhypnotic dose of propofol (1 mg kg-1). Anaesthesia was maintained with 2-4% sevoflurane, O2 and N2O. Anxiety on arrival to operating theatre, at anaesthesia induction and 30 min after emergence was assessed. Parents completed a state-trait anxiety inventory test preoperatively and a post hospitalization behaviour questionnaire a week later to assess children's postoperative behavioural disturbances. Kruskal-Wallis test, Wilcoxon signed rank sum test, Bonferroni's test, Paired t-test, t-test, Pearson and Spearman's rank correlation test, chi2-test were used for statistical analysis. RESULTS: The anxiety level at induction was high in all groups (P < 0.05). There was no difference between groups in respect to anxiety at other measurement times. A relation between preoperative anxiety level and postoperative behavioural disturbances was determined (P < 0.05). Some behavioural disturbances as nightmare/night fear and desire of sleeping with parents were rarely seen in intravenous propofol induction group (P < 0.05). CONCLUSION: Addition of subhypnotic dose of propofol to sevoflurane induction did not reduce the incidence of postoperative behavioural disturbances.

Remifentanil versus propofol sedation for peribulbar anesthesia.

The short onset and offset of remifentanil may allow for accurate dosing of sedative effect with few side-effects and rapid recovery. In this study, remifentanil is compared with propofol for sedation intraocular pressure hemodynamics and oxygen saturation, in patients undergoing cataract surgery with peribulbar block. After ethical committee approval, fifty patients scheduled for one eye cataract surgery were enrolled into the prospective study. Remifentanil infusion was initialized at a rate of 0.04 microg/kg/min, 10 min before peribulbar anesthesia in Remifentanil group (Group R). In Propofol Group (Group P), propofol infusion of 2 mg/kg/h was reduced to 1mg/kg/h. Intraocular pressures of the contralateral eye were measured before and after peribulbar anesthesia and at the end of the operation. Sedation scores (1-5), hemodynamic parameters and saturation were assessed at 5 minute intervals. Heart rate, intraocular pressure, saturation and sedation scores were similar between groups. Intraocular pressures decreased within time in both groups. There were significant changes in mean blood pressure after 5th min between groups (P < 0.05). The infusion of remifentanil or propofol for sedation provided adequate sedation, hemodynamic stability without increasing intraocular pressure during surgery in patients undergoing cataract surgery with peribulbar anesthesia.

The effect of ketamine on acute muscular ischaemia reperfusion in rats.

BACKGROUND AND OBJECTIVE: The aim of this study was to investigate any possible protective effect of ketamine in acute muscular ischaemia and reperfusion injury by measuring malondialdehyde using thiobarbituric acid assay in rats. METHODS: Twelve female Wistar albino rats were anaesthetized with chloral hydrate and randomly assigned into two groups to receive ketamine 1 mg kg(-1) min(-1) or saline infusion. Blood and gastrocnemius muscle samples were obtained 10 min after onset of infusion, before ischaemia. Then, femoral arteries were clamped for 30 min. Blood and muscle samples were obtained at the 30th minute of ischaemia and 10 min after reperfusion. RESULTS: Muscle malondialdehyde concentrations were 27.88 +/- 2.45, 27.62 +/- 3.98 before ischaemia, 32.10 +/- 4.19, 30.77 +/- 2.73 in the 30th minute of ischaemia and 44.34 +/- 2.45, 34.83 +/- 2.78 after reperfusion in saline and ketamine-treated rats, respectively (nmol g(-1), mean +/- SD). The muscle malondialdehyde level after reperfusion was lower in ketamine-treated rats compared to saline group (P < 0.002). Plasma malondialdehyde levels were 3.77 +/- 0.16, 3.78 +/- 0.18 before ischaemia, 3.81 +/- 0.25, 4.00 +/- 0.86 at the 30th minute of ischaemia and 4.00 +/- 0.53, 3.94 +/- 0.95 after reperfusion, respectively, in saline and ketamine-treated rats (micromol L(-1), mean +/- SD). The effect of ketamine on muscular malondialdehyde was not observed in concurrent plasma malondialdehyde levels. CONCLUSION: Ketamine was found to attenuate acute ischaemia-reperfusion injury in muscle tissue in rats (muscular protective). Ketamine may attenuate lipid peroxidation in muscle tissue in tourniquet-requiring manoeuvres.

Effect of low-dose N-acetyl-cysteine infusion on tourniquet-induced ischaemia-reperfusion injury in arthroscopic knee surgery.

BACKGROUND: Temporary occlusion of blood flow is used during arthroscopic knee surgery in order to provide a bloodless surgical field. The resulting ischaemia-reperfusion causes lipid peroxidation, which contributes to tissue injury. The aim of the study was to investigate the effect of low-dose n-acetyl cysteine (NAC) infusion on oxidative stress by determining malondialdehyde (MDA) levels during arthroscopic knee surgery. METHODS: Thirty patients, ASA I - II, undergoing arthroscopic knee debridement under a tourniquet were divided into NAC and control groups. Anaesthesia was induced with propofol, fentanyl and vecuronium bromide and maintained with desflurane in an equal parts O(2)-N(2)O mixture. In the NAC group, an infusion of NAC, 5 mg kg(-1).h(-1), was started after intubation, and continued until extubation. An equal volume of saline was infused to the control group. Duration of ischaemia, anaesthesia time, total dose of NAC infused were also recorded. Venous blood and synovial membrane tissue samples were obtained 10 min after the onset of NAC infusion but before tourniquet inflation (t1), after 30 min of ischaemia (t2), and after 5 min of reperfusion following tourniquet release (t3). RESULTS: Plasma MDA levels were significantly lower in the NAC group on reperfusion. There were no differences between the groups in tissue MDA levels at ischaemia and reperfusion times. CONCLUSION: Low-dose n-acetyl cysteine infusion attenuates lipid peroxidation and ischaemia-reperfusion injury in arthroscopic knee surgery requiring tourniquet application.

Efficacy of prophylactic ketamine in preventing postoperative shivering.

BACKGROUND: Treatment with ketamine and pethidine is effective in postoperative shivering. The aim of this study was to compare the efficacy of low-dose prophylactic ketamine with that of pethidine or placebo in preventing postoperative shivering. METHODS: A prospective randomized double-blind study involved 90 ASA I and II patients undergoing general anaesthesia. Patients were randomly allocated to receive normal saline (Group S, n=30), pethidine 20 mg (Group P, n=30) or ketamine 0.5 mg kg(-1) (Group K, n=30) intravenously 20 min before completion of surgery. The anaesthesia was induced with propofol 2 mg kg(-1), fentanyl 1 microg kg(-1) and vecuronium 0.1 mg kg(-1). It was maintained with sevoflurane 2-4% and nitrous oxide 60% in oxygen. Tympanic temperature was measured immediately after induction of anaesthesia, 30 min after induction and before administration of the study drug. An investigator, blinded to the treatment group, graded postoperative shivering using a four-point scale and postoperative pain using a visual analogue scale (VAS) ranging between 0 and 10. RESULTS: The three groups did not differ significantly regarding patient characteristics. The number of patients shivering on arrival in the recovery room, and at 10 and 20 min after operation were significantly less in Groups P and K than in Group S. The time to first analgesic requirement in Group S was shorter than in either Group K or Group P (P<0.005). There was no difference between the three groups regarding VAS pain scores. CONCLUSION: Prophylactic low-dose ketamine was found to be effective in preventing postoperative shivering.

Cauda-filar paraganglioma with 'silk cocoon' appearance on spinal angiography.

'Silk cocoon' appearance on spinal angiography is pathognomonic to differentiate paragangliomas from several vascular tumors and malformations of cauda-filar region.

Induced hypotension for tympanoplasty: a comparison of desflurane, isoflurane and sevoflurane.

BACKGROUND AND OBJECTIVES: This prospective, randomized, double-blinded study was designed to compare the effects of desflurane, isoflurane and sevoflurane when combined with remifentanil for induced hypotension on surgical conditions and operative field during tympanoplasty. METHODS: Sixty patients undergoing tympanoplasty were enrolled in the study. The patients were randomized into three groups of 20 each to receive the inhalation anaesthetics desflurane, isoflurane or sevoflurane. Propofol 2 mg kg(-1) was administered for induction of anaesthesia in all groups. All patients received a continuous infusion of remifentanil which was titrated between 0.2 and 0.5 microg kg(-1) min(-1) to achieve a mean blood pressure (BP) of 60-70 mmHg. Nitroglycerine was infused if this BP could not be achieved. Arterial pressures were recorded continuously throughout the operation. Surgical conditions were assessed every 20 min by the blinded surgeon using a six-point category scale (0-5). RESULTS: One patient in the desflurane group and two patients in isoflurane group required nitroglycerine to maintain desired mean BP. Sustained controlled hypotension was sufficient in all of the groups throughout surgery. Category scale scores were < or =3 throughout the study, except one patient in the sevoflurane group who had a score of 4 at the 60th minute of the operation. No difference was found among groups when haemodynamic parameters and surgical category scale scores were compared. There were no postoperative respiratory and circulatory complications. CONCLUSION: Desflurane, sevoflurane or isoflurane combined with remifentanil provided adequate induced hypotension and similar operating conditions and any of them could be safely and equally used in anaesthesia for tympanoplasty.

Anesthetic management of a patient with Weill-Marchesani syndrome.

Weill-Marchesani syndrome is characterized by short stature, brachydactylyl, myopia, microspherophakia, lens dislocation, glaucoma, joint stiffness, restricted articular movements and facial features. The anesthetic management of an 11-year-old-male patient with diagnosis of this syndrome is reported.

Propofol attenuates formation of lipid peroxides in tourniquet-induced ischaemia-reperfusion injury.

We studied 20 adult ASA I patients undergoing elective peripheral surgery allocated randomly to one of two groups. In the propofol group (n = 9) anaesthesia was induced with propofol and fentanyl followed by continuous infusion of propofol. In the control group (n = 11), after induction of anaesthesia with thiopentone and fentanyl, anaesthesia was maintained with isoflurane. Concentrations of lipid peroxides in both plasma and muscle tissue samples were measured as thiobarbituric acid-reacting substances (TBARS). Plasma TBARS concentrations increased significantly in the control group at 1, 5, 15, 30 and 45 min after release of the tourniquet to mean 1.83 (SD 0.13), 2.00 (0.12), 2.25 (0.14), 2.30 (0.12) and 2.41 (0.14) mumol litre-1, respectively, compared with pre-reperfusion values (1.64 (0.14) mumol litre-1). In the propofol group this was significant only at 30 min (1.85 (0.03) vs 1.74 (0.04) mumol litre-1). TBARS concentrations of reperfused muscle tissue were significantly higher than pre-reperfusion concentrations in the control group (70.30(10.06) vs 52.13 (5.73) nmol/g wet tissue). We conclude that propofol attenuated ischaemia-reperfusion-induced lipid peroxidation in the therapeutic doses used in anaesthesia.

Distribution of different fibre types of M. extensor carpi radialis longus of the rat.

As revealed by the NADH-diaphorase and myosine ATPase, the M. extensor carpi radialis longus of the rat possesses at least 3 main kinds of fibres, with different distribution on the superficial and deep portions of the muscle. The superficial portion revealed that 67.68% are FG (fast-twitch-glycolytic) fibres, 14.72% are FOG (fast-twitch-oxidative) fibres and 17.60% are SO (slow-twitch-glycolytic) fibres. Already the deep portion revealed that 71.29% are SO (slow-twitch-glycolytic) fibres, 17.46% are FOG (fast-twitch-oxidative-glycolytic) fibres and 11.25% are FG (fast-twitch-glycolytic) fibres. The miosine ATPase reaction was used to demonstrate contracting characteristics. These findings suggest that the movements of fast contraction of the M. extensor carpi radialis longus are predominant.