The effects of ketamine and lidocaine on free radical production after tourniquet-induced ischemia-reperfusion injury in adults.

BACKGROUND: The primary aim of this study was to compare the effects of a small-dose infusion of 2 antioxidant agents, ketamine and lidocaine, on ischemia-reperfusion injury (IRI) in patients undergoing elective lower limb surgery. Ischemia-modified albumin (IMA), lactate, and blood gas levels were all measured and assessed. METHODS: A total of 100 patients who underwent lower extremity surgery were randomized into 3 groups. After spinal anesthesia, the ketamine group (Group K, n=33) was given a ketamine infusion, a lidocaine infusion was administered to the lidocaine group (Group L, n=33), and in the control group (Group C), 0.9% a sodium chloride infusion was performed. Blood samples were obtained for IMA analysis before anesthetic administration (baseline), at 30 minutes of tourniquet inflation (ischemia), and 15 minutes after tourniquet deflation (reperfusion). Arterial blood gas measurements were determined before anesthetic administration and 15 minutes after tourniquet deflation. RESULTS: The lactate and IMA levels at reperfusion were significantly lower in both the ketamine group and the lidocaine group when compared with the control group. CONCLUSION: The administration of both ketamine and lidocaine infusions significantly decreased skeletal muscle IRI-related high lactate and IMA levels. These results suggest the possibility of the clinical application of ketamine or lidocaine infusions in cases of skeletal muscle-related IRI.

Is intra-articular magnesium effective for postoperative analgesia in arthroscopic shoulder surgery?

BACKGROUND: Various medications are used intra-articularly for postoperative pain reduction after arthroscopic shoulder surgery. Magnesium, a N-methyl-D-aspartate receptor antagonist, may be effective for reduction of both postoperative pain scores and analgesic requirements. METHODS: A total of 67 patients undergoing arthroscopic shoulder surgery were divided randomly into two groups to receive intra-articular injections of either 10 mL magnesium sulphate (100 mg/mL; group M, n=34) or 10 mL of normal saline (group C, n=33). The analgesic effect was estimated using a visual analogue scale 1 h, 2 h, 6 h, 8 h, 12 h, 18 h and 24 h after operation. Postoperative analgesia was maintained by intra-articular morphine (0.01%, 10 mg) + bupivacaine (0.5%, 100 mL) patient-controlled analgesia device as a 1 mL infusion with a 1 mL bolus dose and 15 min lock-out time; for visual analogue scale scores >5, intramuscular diclofenac sodium 75 mg was administered as needed during the study period (maximum two times). RESULTS: Intra-articular magnesium resulted in a significant reduction in pain scores in group M compared with group C 1 h, 2 h, 6 h, 8 h and 12 h after the end of surgery, respectively, at rest and with passive motion. Total diclofenac consumption and intra-articular morphine + bupivacaine consumption were significantly lower in group M. Postoperative serum magnesium levels were significantly higher in group M, but were within the normal range. CONCLUSIONS: Magnesium causes a reduction in postoperative pain in comparison to saline when administered intra-articularly after arthroscopic shoulder surgery, and has no serious side effects.

Determination of optimum time for intravenous cannulation after induction with sevoflurane and nitrous oxide in children premedicated with midazolam.

BACKGROUND: It has been shown that early placement of an intravenous line in children administered sevoflurane anesthesia increased the incidence of laryngospasm and movement. However, the optimal time for safe cannulation after the loss of the eyelash reflex during the administration of sevoflurane and nitrous oxide is not known. AIM: The aim of the study was to determine the optimum time for intravenous cannulation after the induction of anesthesia with sevoflurane and nitrous oxide in children premedicated with oral midazolam. METHOD: We performed a prospective, observer-blinded, up-down sequential, allocation study, and children, aged 2-6 years, ASA physical status I, scheduled for an elective procedure undergoing inhalational induction were included in the study. Anesthesia was induced with sevoflurane and nitrous oxide after premedication with oral midazolam. For the first child, 4 min after the loss of the eyelash reflex, the intravenous cannulation was attempted by an experienced anesthesiologist. The time for intravenous cannulation was considered adequate if movement, coughing, or laryngospasm did not occur. The time for cannulation was increased by 15 s if the time was inadequate in the previous patient, and conversely, the time for cannulation was decreased by 15 s if the time was adequate in the previous patient. The probit test was used in the analysis of up-down sequences. RESULTS: A total of 32 children were enrolled sequentially during the study period. The adequate time for effective intravenous cannulation after induction with sevoflurane and nitrous oxide in 50% and 95% of patients were 1.29 min (95% confidence interval, 0.96-1.54 min) and 1.86 min (95% confidence interval 1.58-4.35 min), respectively. CONCLUSION: We recommend waiting 2 min for attempting intravenous placement following the loss of the eyelash reflex in children sedated with midazolam and receiving an inhalation induction with sevoflurane and nitrous oxide.

Oral magnesium lozenge reduces postoperative sore throat: a randomized, prospective, placebo-controlled study.

BACKGROUND: Postoperative sore throat (POST) is an undesirable complaint after orotracheal intubation. Magnesium is a noncompetitive N-methyl-D-aspartate receptor antagonist thought to be involved in the modulation of pain. The present study aimed to investigate the effect of preoperative administration of oral magnesium lozenge on POST. METHODS: Seventy patients undergoing orthopedic surgery were randomly allocated into two groups, to either receive placebo (control) or magnesium lozenges (magnesium) to be dissolved by sucking 30 min preoperatively. Patients were assessed for incidence and severity (four-point scale, 0-3) of POST at 0, 2, 4, and 24 h postoperatively. The primary outcome was sore throat at 4 h after surgery. The secondary outcome was the severity of POST at four evaluation time-points postoperatively. RESULTS: The incidence of POST at 4 h was higher in control group than in magnesium group (95% CI: 26%, 14-42%; P=0.032). The highest incidence of POST occurred at the second hour after surgery, with the rate of 23% in the magnesium group and 57% in the control group (95% CI: 34%, 20-51%; P=0.007). The severity of POST was significantly lower in the magnesium group at 0 (P=0.007) and 2 h (P=0.002). The incidences of POST at 0 and 24 h and severity scores at 4 and 24 h were not significantly different between the groups. CONCLUSIONS: The administration of magnesium lozenge 30 min preoperatively is effective to reduce both incidence and severity of POST in the immediate postoperative period.

Regional anesthesia with a single spinal anesthesia using hyperbaric bupivacaine in a child with arthroglyposis multiplex congenita.

Arthrogryposis multiplex congenita (AMC) consists of complex congenital anomalies characterized by multiple contractures. Anesthetic management of these patients requires special care: as this disease often progresses until dysfunction of multiple organ systems occur, it may have an impact on the anesthetic management. Here, we report a case of AMC undergoing urgent surgery for open tibia fracture who had difficult airway management because of limited mouth opening. The anesthetic management of this patient is represented in light of the literature.

Effect of off-pump and on-pump coronary artery bypass grafting on renal function.

BACKGROUND: Coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB) has the risk of renal dysfunction. The cause of renal dysfunction after CPB is multifactorial, such as nonpulsatile flow, renal hypoperfusion, hypothermia, and duration of CPB. This study compared off-pump technique with on-pump technique on renal function in patients who underwent CABG. METHODS: Sixty patients with normal preoperative renal functions undergoing CABG were randomly assigned to conventional revascularization with CPB (on-pump) or beating heart revascularization (off-pump). Renal functions were assessed up to 10 days postoperatively. RESULTS: Creatinine clearance was found to be significantly higher in the off-pump group than in the on-pump group (p<.05). The off-pump group had significantly less increase in creatinine levels when compared with the on-pump group (p<.05). The free water clearance values decreased similarly in both groups; however, the recovery was more prompt in the off-pump group (p<.05). No significant differences were found in the prevalence of postoperative hemodialysis. CONCLUSION: The off-pump technique may provide a positive contribution and sufficient protection on postoperative renal functions in patients undergoing CABG.

Preoperative analgesia management with rofecoxib in thoracotomy patients.

OBJECTIVE: Pain management after thoracotomy is significant because pain reduces the postoperative respiratory performance. In this study, the analgesic efficacy and safety of rofecoxib in thoracotomy patients were evaluated. DESIGN: A prospective, randomized, double-blind, and placebo-controlled study. SETTING: This study was performed in the Meram Medical School of Selcuk University Departments of Cardiovascular Surgery and Anesthesiology. PARTICIPANTS: Sixty patients undergoing elective thoracic surgery via thoracotomy were randomized to receive either oral placebo or rofecoxib, 50 mg, 1 hour before surgery. INTERVENTIONS: All patients received a standard anesthetic. Pain scores, sedation scores, heart rate, mean arterial pressure, respiratory rate, analgesic requirements, and side effects were noted 2, 4, 8, 12, 18, 24, 32, 40, and 48 hours after operation. MEASUREMENTS AND MAIN RESULTS: There were no significant differences between the 2 study groups with respect to demographics, sedation score, intraoperative blood loss, and postoperative drainage. Compared with placebo, morphine consumption and pain scores at rest and during coughing were significantly lower with rofecoxib. CONCLUSIONS: The preoperative administration of rofecoxib, 50 mg, provides significant analgesia for postoperative pain relief and decreases additional opioid requirements after thoracotomy.

Methylprednisolone prevents inflammatory reaction occurring during cardiopulmonary bypass: effects on TNF-alpha, IL-6, IL-8, IL-10.

OBJECTIVE: This study examined the correlation between tumour necrosis factor-alpha (TNF-alpha), interleukin (IL)-6 and IL-8, IL-10 and methylprednisolone pretreatment. METHODS: This is a prospective, randomized and double-blinded study. Sixty patients undergoing coronary artery bypass grafting (CABG) were randomized to receive either intravenous methylprednisolone (n = 30, Group M) or intravenous placebo (n = 30, Group S). The patients received intravenously either 30 mg/kg methylprednisolone (Group M) or placebo (Group S) 10 min before and after cardiopulmonary bypass (CPB). In an intensive care unit (ICU), four additional doses were given at 6-hourly intervals. Blood samples for the measurements of TNF-alpha, IL-6, IL-8 and IL-10 were obtained before induction of anaesthesia (T0 = control value), after induction (T1), before starting CPB (T2), after aortic declamping (T3), at the end of CPB (T4) and 6 hours (T5), 12 hours (T6) and 24 hours (T7) after skin closure. Creatine kinase (CK) and creatine kinase isoenzyme MB (CK-MB) were evaluated at the following intervals: T0, T5, T6 and T7. RESULTS: When compared with the control value, TNF-alpha, IL-6 and IL-8 significantly increased in Group S and Group M (p < 0.05), but these values were significantly greater in Group S than in Group M (p < 0.05). In comparison with the control value, IL-10 increased in both groups (p < 0.05), but was significantly greater in Group M than in Group S (p < 0.05). CK and CK-MB were increased in both groups in postoperative values compared to control values. In Group S, CK and CK-MB levels were significantly lower than in Group M (p < 0.05). CONCLUSION: In this study, we have found that preoperative administration of methylprednisolone has decreased TNF-alpha, IL-6 and IL-8 release, and increased the perfusing IL-10 levels after CPB. Thus, methylprednisolone may decrease the inflammatory response during the CPB procedure.

The effect of environmental tobacco smoke on the dose requirements of rocuronium in children.

BACKGROUND: Smoking affects the pharmacodynamic and pharmacokinetic behaviour of several drugs. The aim of this study was to evaluate the effects of environmental tobacco smoke on onset and recovery time after single dose rocuronium in children. METHODS: Forty children between 4 and 10 years were enrolled into the study. Children who have no familial smoking history were included in the first group whereas passive smokers included in the second group. Sevoflurane in 50% O2 and 50% N2O was used for induction of anaesthesia. Evoked adductor pollicis electromyography was used to monitor neuromuscular block. The T95 and T25 values were recorded. RESULTS: The T95 values (+/-sd) for rocuronium were 110.1 +/- 39.3 s and 79.3 +/- 35.6 s for group 1 and group 2, respectively (P < 0.05). The T25 value of group 2 was 40.1 +/- 10.6 min and compared with group 1 values (30.85 +/- 7.02 min) it was significantly longer (P < 0.01). CONCLUSION: This study shows that passive smoking children consume less rocuronium than nonsmokers during similar anaesthesia. We think that a history of passive smoking must also be taken into consideration during preoperative evaluation of paediatric patients.

The in vitro effects of remifentanil and fentanyl on isolated human right atria and saphenous veins.

OBJECTIVE: To determine the myocardial and vascular effects of remifentanil and fentanyl in human atria and saphenous veins. DESIGN: In vitro, prospective with repeated measures. SETTING: University research laboratory. INTERVENTIONS: The direct effects of remifentanil and fentanyl on the electrical stimulation-induced contraction of nonfailing human atrium and saphenous veins contracted with 5-hydroxytryptamine were studied. MEASUREMENTS AND MAIN RESULTS: In human atrial trabeculae, cumulative (10(-9)-10(-5) mol/L) added remifentanil had no effect on contractile force, compared with untreated muscles (p > 0.05). The force of contraction was significantly less than control values with concentrations of fentanyl ranging from 10(-8) to 10(-5) mol/L (p < 0.05). At the highest concentration (10(-5) mol/L), the inhibition by fentanyl of the electrical stimulation-induced contraction was 40.6% +/- 6.32%. In human saphenous vein strips preconstricted with 5-hydroxytryptamine, remifentanil (10(-8)-10(-5) mol/L) and fentanyl (10(-8)-10(-5) mol/L) produced "concentration-dependent" relaxation when compared with the control contraction value (p < 0.05). The IC(50) was similar with remifentanil and fentanyl and the E(max) of fentanyl was significantly higher than remifentanil (p < 0.05). The venodilatory effects of remifentanil and fentanyl were similar on veins with or without endothelium (p > 0.05). CONCLUSIONS: Remifentanil has no direct effect on the contraction of myocardium. Fentanyl inhibits the electrical stimulation-induced contraction in human right atrial muscles in vitro. Remifentanil and fentanyl produce "concentration-dependent" relaxation in human saphenous vein strips independent from the endothelium.