Effects of single-dose gabapentin on postoperative pain and morphine consumption after cardiac surgery.

OBJECTIVE: The purpose of this study was to evaluate the analgesic effect of single-dose preoperative gabapentin on postoperative pain and morphine consumption after cardiac surgery. DESIGN: A randomized, double-blind, placebo-controlled, clinical study. SETTING: A single university hospital. PARTICIPANTS: Sixty patients undergoing coronary artery bypass graft surgery. INTERVENTIONS: Patients were randomly allocated into 2 groups preoperatively either to receive 600 mg of oral gabapentin (GABA) or placebo (PLA) 2 hours before the operation. After extubation, an anesthesiologist blinded to the groups recorded pain scores both at rest and with cough with a 10-point verbal rating scale and sedation scores at 2, 6, 12, 18, 24, and 48 hours. Cumulative morphine consumption and the incidence of side effects were recorded during the study period. MEASUREMENTS AND MAIN RESULTS: The total morphine consumption was lower in the GABA group (6.7 ± 2.5 mg) than in the PLA group (15.5 ± 4.6 mg, p < 0.01). Pain scores at rest were significantly lower in the GABA group than in the PLA group throughout the study period (p < 0.05 in all measurement times). Pain scores at 2, 6, and 12 hours during coughing were significantly lower in the GABA group (p < 0.05). The number of oversedated patients was significantly higher in the GABA group at 2, 6, and 12 hours of study compared with PLA (p < 0.001 at 2 and 6 hours and p < 0.02 at 12 hours). The postoperative mechanical ventilation period was significantly prolonged in the GABA group (6.6 ± 1.2 hours) compared with the PLA group (5.5 ± 1 hours, p < 0.01). Nausea incidence was significantly lower in the GABA group (n = 9) than in the PLA group (n = 18, p = 0.02). CONCLUSIONS: Oral GABA at a dose of 600 mg given before cardiac surgery significantly reduced postoperative morphine consumption and postoperative pain both at rest and with cough.

The effects of propofol infusion on hepatic and pancreatic function and acid-base status in children undergoing craniotomy and receiving phenytoin.

BACKGROUND: In this study, we investigated the effects of propofol infusion on hepatic and pancreatic enzymes and acid-base status compared with baseline values in children undergoing craniotomy who were receiving phenytoin for antiepileptic prophylaxis. METHODS: In this prospective clinical study, we measured the serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyl transpeptidase (GGT), alkaline phosphatase (ALP), pancreatic amylase, lipase, and triglyceride levels of 30 children ranging from 4 to 12 yr. All children received propofol anesthesia and were taking phenytoin for antiepileptic prophylaxis. Patients already receiving phenytoin were continued on their medication. Peroral 5 mg x kg(-1) x d(-1) phenytoin was started in patients who were not receiving phenytoin. Serum AST, ALT, GGT, ALP, bilirubin, pancreatic amylase, lipase, and triglyceride levels were studied on admission to the hospital, 1 day before surgery, and on postoperative Days 1, 3, 5, and 7. Arterial blood gas samplings were taken after tracheal intubation, during the operation (2nd and 4th h), just after extubation, and 1, 2, 6, and 12 h after extubation. RESULTS: Serum AST, ALT, GGT, ALP, pancreatic amylase, lipase, and triglyceride levels were increased significantly in the postoperative period compared with baseline with a peak value on postoperative Day 1 and returned to normal values within a week. Base excess levels after extubation were significantly decreased compared with baseline. They were in the normal range, however, and returned to baseline values by 6 h after surgery. There were no clinical signs of hepatitis or pancreatitis. Bilirubin levels were normal. None of the children developed complications related to the liver or pancreas during the 4-6 mo after surgery. CONCLUSIONS: Despite the slightly increased pancreatic and hepatic enzyme levels during the postoperative period, anesthesia maintenance with propofol in children undergoing craniotomy had no significant clinical effect on the acid-base status or pancreas or liver enzymes.

The analgesic effect of gabapentin as a prophylactic anticonvulsant drug on postcraniotomy pain: a prospective randomized study.

BACKGROUND: Gabapentin is an anticonvulsant drug that has analgesic properties for acute postoperative pain. However, the analgesic effect of gabapentin as an antiepileptic prophylactic drug on patients undergoing craniotomy is unclear. In this study, we evaluated the postoperative effectiveness of gabapentin on acute postoperative pain when it is used for antiepileptic prophylaxis in patients undergoing craniotomy for supratentorial tumor resection. METHODS: Eighty patients undergoing craniotomy for supratentorial tumor resection were randomly assigned into two groups. Patients in Group G (n = 40) received oral gabapentin (3 x 400 mg), and patients in Group P (n = 40) received oral phenytoin (3 x 100 mg) for 7 days before the operation and postoperatively. An identical anesthesia protocol was performed for both the groups. Anesthesia was maintained with propofol and remifentanil infusion. Patient-controlled analgesia with morphine was used, and pain levels were measured. The antiepileptic-related side effects, anesthetic consumption, duration of anesthesia and surgery, tracheal extubation time, postoperative pain scores, morphine consumption, and sedation scores were recorded. RESULTS: Thirty-seven patients in Group G and 38 patients in Group P completed the study. During the preoperative period in Group G, one patient had severe fatigue, one had severe dizziness, and one patient's surgical procedure was changed. The median plasma levels of gabapentin were 34 micromol/mL (range, 23-51 micromol/mL) in 34 patients. In Group P, one patient withdrew from the study preoperatively and one developed transient neurological symptoms postoperatively. The demographic data and mean duration of anesthesia and surgery were similar in both the groups. The total propofol and remifentanil consumption in Group G (1847 +/- 548 mg/3034 +/- 1334 microg) was significantly less than that of Group P (2293 +/- 580 mg/4287 +/- 1282 microg) (P = 0.01). However, tracheal extubation could be done earlier in Group P (4.5 +/- 2 min) than in Group G (16.6 +/- 22 min) (P < 0.001). Pain scores were significantly higher in Group P at 15 min, 30 min, and 1 h (P < 0.001). The total morphine consumption was also significantly higher in Group P (33 +/- 17 mg vs 24 +/- 19 mg) (P = 0.01). The postoperative sedation scores were significantly higher in Group G at 15 min, 30 min, 1 h, and 2 h (P < 0.001). CONCLUSIONS: The administration of gabapentin to patients undergoing craniotomy for supratentorial tumor resection was effective for acute postoperative pain. It also decreased analgesic consumption after surgery. However, it may lead to side effects such as delayed tracheal extubation and increased sedation postoperatively.

Internal jugular vein diameter in pediatric patients: are the J-shaped guidewire diameters bigger than internal jugular vein? An evaluation with ultrasound.

AIM: This study investigates whether the diameters of right internal jugular vein (RIJV) are suitable for the use of 'big radius curved J-tip' Seldinger wires in pediatric patients. METHODS: One-hundred and thirty-five children, 1 month to 15 years of age, scheduled for pediatric surgery were divided into four subgroups according to their age (0-12 months, 1-2 years, 2-6 years old, and >6 years). Patients in the 0-12 months group were further divided into two groups as 0-6 months and 7-12 months of age to evaluate RIJV characteristics in detail. Following anesthesia induction, depth, diameter, and area of RIJV were measured with ultrasound at the level of cricoid cartilage and sterno-clavicular junction in supine and Trendelenburg position. RESULTS: Infants in the 0-6 months of age group had the least mean diameter of RIJV at both the cricoid cartilage and the sternoclavicular junction level (0.484 +/- 0.132 and 0.499 +/- 0.136 cm). The aforementioned diameter was significantly lower than the values of other age groups (P < 0.05). Trendelenburg position did not increase RIJV diameter in children below 6 and cross-sectional area below 2 years old. Correlations between age, height, weight, head circumference and RIJV diameter, cross-sectional area, depth from the skin were weak. CONCLUSION: The diameter of the IJV in pediatric patients, especially infants, is often smaller than the diameter of the J-tip guidewire curve. We speculate that this may lead to impeded guidewires and failed cannulation. It must also be kept in mind that the Trendelenberg position might not facilitate IJV cannulation in children <2 years of age.

The effect of 2 different concentrations of rectal ketamine on its premedicant features in children.

OBJECTIVE: To investigate whether changing concentration and volume of ketamine for rectal premedication would change the premedication and recovery characteristics. METHODS: A prospective, randomized, clinical study was designed in Yeditepe University Hospital, Istanbul, Turkey in 2006-2007. The study group included children weighing 10-20 kg, American Society of Anesthesiologists grade I, scheduled for inguinal hernia repair or circumcision under general anesthesia with orotracheal intubation and caudal blockade. Children were rectally premedicated with 10 mg.kg-1 ketamine 5% in group K, and 2.5% in the Group K1/2, 45 minutes before anesthesia. Anesthesia was induced and maintained by inhalation. Sedation scores at 15 minutes intervals in the preinduction area, parental separation scores, induction and recovery characteristics, time to discharge and a questionnaire at 24th postoperative hour were recorded. RESULTS: One hundred children were randomized into 2 groups of 50. Thirty minutes 1.2 versus 0.48, p=0.018 and 45 minutes 2.24 versus 1.8, p=0.027 following premedication group K1/2 had significantly lower mean sedation scores than group K. Separation, induction quality scores, induction duration, secretion scores either during induction or postoperative period, and recovery characteristics were all comparable in both groups. CONCLUSION: Although adequate sedation was obtained for most of the children in both groups, rectal premedication with 5% ketamine resulted in higher levels of sedation appearing earlier than that of 2.5% ketamine, while change of volume and concentration had no effect on recovery characteristics.

Dexmedetomidine as an adjunct to anesthetic induction to attenuate hemodynamic response to endotracheal intubation in patients undergoing fast-track CABG.

During induction of general anesthesia hypertension and tachycardia caused by tracheal intubation may lead to cardiac ischemia and arrhythmias. In this prospective, randomized study, dexmedetomidine has been used to attenuate the hemodynamic response to endotracheal intubation with low dose fentanyl and etomidate in patients undergoing myocardial revascularization receiving beta blocker treatment. Thirty patients undergoing myocardial revascularization received in a double blind manner, either a saline placebo or a dexmedetomidine infusion (1 microg/kg) before the anesthesia induction. Heart rate (HR) and blood pressure (BP) were monitored at baseline, after placebo or dexmedetomidine infusion, after induction of general anesthesia, one, three and five minutes after endotracheal intubation. In the dexmedetomidine (DEX) group systolic (SAP), diastolic (DAP) and mean arterial pressures (MAP) were lower at all times in comparison to baseline values; in the placebo (PLA) group SAP, DAP and MAP decreased after the induction of general anesthesia and five minutes after the intubation compared to baseline values. This decrease was not significantly different between the groups. After the induction of general anesthesia, the drop in HR was higher in DEX group compared to PLA group. One minute after endotracheal intubation, HR significantly increased in PLA group while, it decreased in the DEX group. The incidence of tachycardia, hypotension and bradycardia was not different between the groups. The incidence of hypertension requiring treatment was significantly greater in the PLA group. It is concluded that dexmedetomidine can safely be used to attenuate the hemodynamic response to endotracheal intubation in patients undergoing myocardial revascularization receiving beta blockers.

Comparison of the effect of sevoflurane and halothane anesthesia on the fall in heart rate as a predictor of successful single shot caudal epidural in children.

OBJECTIVE: To investigate the effect of sevoflurane anesthesia on heart rate HR fall with the injection of the initial drug in caudal space to confirm the correct needle placement. METHODS: After the ethical approval was obtained from the hospital's ethics committee, a prospective, randomized, clinical study was designed in Yeditepe University Hospital, in 2007. Children aged 1-12 years, scheduled for infraumbilical surgery under general anesthesia, and caudal block were included in the study. Anesthesia was induced, and maintained by sevoflurane in group S (n=85), and by halothane in group H (n=82). Baseline HR was recorded before the caudal block was performed. The HR changes during the initial dose, and total drug injection were recorded followed by 2 more HR recordings taken 5, and 10 minutes after caudal injection. The success of the block was recorded by a blind observer. RESULTS: There were 167 children included in the study. Caudal block success was 96.5% in group S, and 97.6% in group H. Basal HR was 110.9 +/- 10.9 in group S, and 105.9 +/- 10.1 in group H. Following the initial drug injection, mean HR was 109.8 +/- 10.9 in group S, and 102.9 +/- 9.9 in group H. It was significantly lower than the baseline in group H. The only significant decrease in the HR of the patients in group S was at the tenth minute following caudal injection. CONCLUSION: The decrease in HR with drug injection has no value to predict the success of caudal block under sevoflurane anesthesia.

Epidural anesthesia may attenuate lipid peroxidation during aorto-femoral surgery.

PURPOSE: To determine the effect of epidural anesthesia (EP) on oxygenation of the chronically ischemic limb in patients undergoing aorto-femoral bypass grafting and to assess whether it produces an alteration of lipid peroxidation and antioxidant status following revascularization. METHODS: In this prospective, randomized, single-blinded study 40 ASA II or III patients undergoing elective aorto-femoral bypass grafting were allocated to receive general anesthesia (group GA, n = 20), or epidural + GA (group EP, n = 20) during surgery. Femoral venous blood-gas status, activities of the protecting antioxidant enzymes superoxide dismutase (SOD), glutathione peroxidase (GSH-px), glutathione reductase (GSH-rd), glutathione (GSH) and thiobarbituric acid-reactive substances (TBARS) as a marker of lipid peroxidation were determined in blood samples taken from the femoral vein at different intervals before and after revascularization. RESULTS: Before the induction of anesthesia in group EP, femoral venous PO(2) [mean (standard deviation), 95% confidence interval] increased after achieving an adequate level of blockade by EP extending to the dermatomal level of T6-8 [29.32 (4.6), 26.34-32.30 to 36.29 (4.6), 33.37-39.22 mmHg, P < 0.05]. Femoral venous PO(2) was similar in both groups thereafter. In the GA group a significant increase in erythrocyte TBARS was observed immediately after restoration of blood flow when compared with baseline values [221.32 (102), 148.35-294-29 to 337.26 (123) 248.99-425.53 nmol*g(-1) hemoglobin, P < 0.01] but not at any other moment. In the EP group TBARS did not increase throughout the study. Within group comparisons revealed no significant differences in GSH, GSH-px, GSH-rd and SOD. CONCLUSION: In patients with atherosclerotic aorto-iliac occlusive disease EP may possibly attenuate lipid peroxidation following revascularization but has no effect on antioxidant enzyme activities.