Karamehmet Yildiz

Inhibitory effects of desflurane and sevoflurane on oxytocin‐induced contractions of isolated pregnant human myometrium

Background:  In this study, we investigated the inhibitory effects of desflurane and sevoflurane on oxytocin‐induced contractions of isolated human myometrium.

Comparison of patient‐controlled analgesia with and without a background infusion after appendicectomy in children

Background: There have been many studies using patient‐controlled analgesia (PCA) and opioids for postoperative analgesia in children. In this study, we investigated the efficacy, usefulness and analgesic consumption of two different PCA programmes [bolus dose alone (BD) or bolus dose with background infusion (BD + BI)] to evaluate postoperative analgesia for children after emergency appendicectomy.

Hemodynamic and blockade effects of high/low epinephrine doses during axillary brachial plexus blockade with lidocaine 1.5%: a randomized, double-blinded study

Background and Objectives: Although epinephrine commonly is added to local anesthetics for regional anesthesia, rarely it may cause undesirable hemodynamic side effects. This study compared the hemodynamic and blockade effects of 25 and 200 μg epinephrine during axillary brachial plexus blockade with lidocaine 1.5%. Methods: Sixty American Society of Anesthesiologist classification I or II patients were divided randomly into 3 groups. Patients in group 1 received 5 mL of saline containing 25 μg epinephrine and then 35 mL of 1.5% lidocaine; patients in group 2 received 5 mL of saline alone and then 200 μg of epinephrine mixed with 35 mL of 1.5% lidocaine; patients in group 3 received 5 mL of saline alone and then 35 mL of 1.5% lidocaine. Hemodynamic data were measured for 1 to 10 minutes at 1-minute intervals after axillary injection. The duration time of motor and sensory block was recorded. Results: Complete anesthesia was achieved in 85% of patients in groups 1 and 3 and 90% in group 2. Motor block duration was significantly longer in group 2 than in groups 1 and 3 (P < .05). There were no significant differences in analgesia between groups 1 and 2. Analgesia duration was significantly longer in groups 1 and 2 than in group 3 (P < .05). Heart rate from the 3rd to 6th minute was higher in group 2 than in groups 1 and 3 (P < .05). Systolic arterial pressure from the 3rd to 5th minute and diastolic arterial pressure from 2nd to 6th minute were higher in group 2 than in groups 1 and 3 (P < .05). Conclusions: Low-dose epinephrine offers more stable hemodynamics and similar blockade, and thus may be beneficial for patients undergoing forearm and hand surgery who are at risk for tachycardia and/or hypertension.

Comparison of recovery properties of desflurane and sevoflurane according to gender differences

Background:  The aim of this study was to investigate the recovery properties of desflurane and sevoflurane in patients undergoing elective surgery, according to the gender differences.

Randomized, double-blinded comparison of tropisetron and placebo for prevention of postoperative nausea and vomiting after supratentorial craniotomy.

This prospective, randomized, placebo-controlled, double-blinded study was designed to evaluate the efficacy of tropisetron in preventing postoperative nausea and vomiting after elective supratentorial craniotomy in adult patients. We studied 65 ASA physical status I–III patients aged 18 to 76 years who were undergoing elective craniotomy for resection of various supratentorial tumors. Patients were divided into two groups and received either 2 mg of tropisetron (group T) or saline placebo (group P) intravenously at the time of dural closure. A standard general anesthetic technique was used. Episodes of nausea and vomiting and the need for rescue antiemetic medication were recorded during 24 hours postoperatively. Demographic data, duration of surgery and anesthesia, and sedation scores were comparable in both groups. Nausea occurred in 30% of group T patients and in 46.7% of group P patients (P > .05). The incidence of emetic episodes was 26.7% and 56.7% in the two groups (P < .05). Rescue antiemetic medication was needed in 26.7% and 60% of the patients (P < .05). Administration of a single dose of tropisetron (2 mg intravenously) given at the time of dural closure was effective in reducing postoperative nausea and vomiting after elective craniotomy for supratentorial tumor resection in adult patients.

Inhibitory effects of desflurane and sevoflurane on contractions of isolated gravid rat myometrium under oxytocin stimulation.

Background: We studied the inhibitory effects of desflurane and sevoflurane on oxytocin‐induced contractions of isolated gravid rat myometrium.

Comparison of Effects of Different Dexmedetomidine and Chloral Hydrate Doses Used in Sedation on Electroencephalography in Pediatric Patients

The aim of this study was to compare the efficacy and safety of different oral chloral hydrate and dexmedetomidine doses used for sedation during electroencephalography (EEG) in children. One hundred sixty children aged 1 to 9 years with American Society of Anesthesiologists physical status I-II who were uncooperative during EEG recording or who were referred to our electrodiagnostic unit for sleep EEG were included to the study. The patients were randomly assigned into 4 groups. In groups D1 and D2, patients received oral dexmedetomidine doses of 2 and 3 µg/kg, respectively. In group C1 and C2, patients received oral chloral hydrate doses of 50 and 100 mg/kg, respectively. The induction time was significantly shorter in group C2 compared with other groups (P = .000). The rate of adverse effects was significantly higher in group C2 compared with the dexmedetomidine groups (D1 and D2; P = .004). In conclusion, dexmedetomidine can be used safely for sedation during EEG in children.

Comparing the relaxing effects of desflurane and sevoflurane on oxytocin-induced contractions of isolated myometrium in both pregnant and nonpregnant rats

In this study, the effects of 2 volatile anesthetics, desflurane and sevoflurane, on oxytocin-induced contractions of isolated myometrium in pregnant and nonpregnant rats were compared. Twenty pregnant and 20 nonpregnant Wistar albino rats were studied at 19 to 20 days’ gestation (term, 22 days). A total of 40 myometrial strips were obtained from pregnant and nonpregnant rats, and each of these was randomly assigned to 1 of 4 groups (n=10, each group). After spontaneous myometrial contractions were induced in the De Jalon solution, the effects of 0.5, 1, and 2 minimum alveolar anesthetic concentrations (MAC) of desflurane or sevoflurane, in the absence and presence of oxytocin (2×10−9 M), were investigated. Oxytocin significantly increased the amplitude and duration of spontaneous contractions in longitudinal myometrial strips (P < .05), but not the frequency. Both agents (except for 0.5 MAC in the nonpregnant group) inhibited the duration, amplitude, and frequency of induced contractions in a dose-dependent manner. The inhibitory potencies of desflurane and sevoflurane were similar. It was found that isolated strips of pregnant rat myometrium were more sensitive to the inhibitory effects of both agents than were the nonpregnant rat myometrial strips.

Comparison of preincisional infiltrated levobupivacaine and ropivacaine for acute postoperative pain relief after septorhinoplasty.

BACKGROUND To maintain a high standard of patient care, it is essential to provide adequate pain management in patients who undergo nasal surgery. Levobupivacaine and ropivacaine are relatively new long-acting local anesthetics. OBJECTIVE The aim of this study was to compare the analgesic effect and blood loss of preincisional levobupivacaine HCl 0.25% and ropivacaine HCl 0.375% in patients undergoing septorhinoplasty. METHODS Sixty American Society of Anesthesiologists (ASA) I and II patients (18-55 years old) who were scheduled for elective open technique septorhinoplasty under general anesthesia were recruited for this study. The anesthetic technique was standardized for both groups. Preoperative and postoperative hemoglobin levels were recorded for all patients. Patients were assigned randomly to 1 of 2 study groups, and preincisional surgical field infiltration with 5 mL of 0.5% levobupivacaine plus 5 mL of 0.9% saline (group L; n = 30) or 5 mL of 0.75% ropivacaine plus 5 mL of 0.9% saline (group R; n = 30) was performed by the same surgeon. The degree of pain was measured by visual analogue scale (VAS) for pain and recorded at multiple time points in all patients after surgery. RESULTS The analgesic effect at 2 hours in the postanesthesia care unit (PACU) and at 24 hours postoperatively did not differ significantly between the 2 local anesthetics (P > 0.05). Pain scores of patients decreased after the 24 hours in levobupivacaine group and ropivacaine group when compared with 0-minute VAS values, and this was statistically significant (P < 0.05). No significant difference was observed between groups with respect to the preoperative and postoperative hemoglobin (P = 0.767 and 0.824, respectively) values. CONCLUSIONS Local tissue infiltration with 0.25% levobupivacaine or 0.375% ropivacaine is similarly effective in reducing the postoperative pain associated with septorhinoplasty.

Effects of naloxone and flumazenil on antinociceptive action of acetaminophen in rats

BACKGROUND Studies of acetaminophen suggest that multiple nociceptive pathways are involved in the drugs analgesic action. OBJECTIVE The purpose of this study was to determine whether naloxone and flumazenil were able to modify or antagonize the antinociceptive effect of acetaminophen in rats. METHODS Adult albino Wistar rats were used in the study and randomly allocated to 1 of 4 groups. The acetaminophen group (A group) was administered IP saline and then 300 mg/kg IP acetaminophen 5 minutes thereafter. The acetaminophen + naloxone group (AN group) was pretreated with 1 mg/kg IP naloxone, followed by 300 mg/kg IP acetaminophen 5 minutes later. The acetaminophen + flumazenil group (AF group) was pretreated with 1 mg/kg IP flumazenil, followed by 300 mg/kg IP acetaminophen 5 minutes later. The control group received 2.5 mL IP saline, followed by an additional 2.5 mL IP injection of saline 5 minutes later. The paw-withdrawal latency period of the rats was assessed by an investigator blinded to treatment using the hot-plate test at 30, 45, 60, and 90 minutes after administration of acetaminophen. RESULTS Thirty-two rats were evenly randomized by envelope method into 4 groups of 8 rats each. Baseline values for the A, AN, AF, and control groups were not significantly different (9.1 [2.3], 10.5 [2.7], 9.8 [3.0], and 8.9 [1.4] sec, respectively). In the AF group, flumazenil appeared to antagonize the analgesic effect exerted by the acetaminophen in the hot-plate test (30 min, 10.3 [3.7] sec; 45 min, 11.7 [5.1] sec; 60 min, 12.1 [5.1] sec; and 90 min, 12.2 [4.9] sec) and values were not significantly different from those obtained in the control group (30 min, 9.8 [2.2] sec; 45 min, 9.0 [1.6] sec; 60 min, 9.2 [1.6] sec; and 90 min, 8.5 [2.0] sec). In the AN group, naloxone did not significantly affect the values observed in the hot-plate test (30 min, 18.0 [4.5] sec; 45 min, 21.5 [7.8] sec; 60 min, 20.5 [5.9] sec; and 90 min, 22.3 [7.4] sec) and values at all time points were not significantly different from those obtained in the A group (30 min, 17.8 [7.6] sec; 45 min, 20.9 [6.9] sec; 60 min, 21.5 [7.3] sec; and 90 min, 23.8 [8.6] sec). All postbaseline values in the A and AN groups were significantly increased versus baseline and versus the control group values (all, P < 0.05). All postbaseline values in the A group were significantly greater than those in the AF group (all, P < 0.05). CONCLUSION Flumazenil antagonized the analgesic effect exerted by acetaminophen, while naloxone had no significant effect on acetaminophens antinociceptive action in this pain model in rats.