Hasan Kocoglu

Effect of Dexmedetomidine on Ischemia-Reperfusion Injury in Rat Kidney: A Histopathologic Study

Ischemia-reperfusion (I-R) injury remains the leading cause of acute renal failure. The purpose of this experimental study was to determine the role of dexmedetomidine on histologic alterations induced by renal I-R in rats. In the present study, thirty male Sprague-Dawley rats weighing 200–220 g were randomly assigned into three groups: the sham-control group (group 1, n = 10), the R/untreated group (group 2, n = 10), and the I-R/dexmedetomidine-treated group (group 3, n = 10). For group one, we performed a sham operation. The abdomen was dissected, the right kidney was harvested, and then the left renal pedicle exposed. Renal clamping was not applied. For group 2, rats underwent left renal ischemia for 60 minutes followed by reperfusion for 45 minutes. For group 3, the same surgical procedure as in group 2 was performed, and dexmedetomidine (100 μg/kg, intraperitoneal) was administrated at the starting time of reperfusion. The rats were sacrificed after reperfusion, and the kidney tissue was harvested. The histopathological score in the kidney of the I-R/dexmedetomidine-treated group rats was significantly lower than that of I-R/untreated group rats. This score in I-R/untreated group rats was higher than the other two groups, which was statistically significant. In the I-R/untreated group rats, kidneys of untreated ischemia rats showed tubular cell swelling, cellular vacuolization, pyknotic nuclei, medullary congestion, and moderate to severe necrosis. Treatment with dexmedetomidine shows normal glomeruli and slight edema of the tubular cells. These findings provide the first evidence that dexmedetomidine can reduce the renal injury caused by I-R of the kidney, and may be useful in enhancing the tolerance of the kidney against renal injury.

Serum Levels of NT-ProBNP as an Early Cardiac Marker of Carbon Monoxide Poisoning

Acute carbon monoxide (CO) poisoning may cause cardiotoxicity. The natriuretic peptides, including atrial natriuretic peptide, brain natriuretic peptide (BNP), N-BNP, and NT-proBNP (N-terminal pro brain natriuretic peptide), are endogenous cardiac hormones that may be secreted upon myocardial stress. The aim of this study was to assess the plasma NT-proBNP level in acute CO poisoning and to compare it with healthy control. After approval by the ethical committee, 15 healthy controls and 15 patients admitted to the Gaziantep University Hospital (Gaziantep, Turkey) between January 2005 and July 2005 with the diagnosis of carbon monoxide poisoning were studied. Echocardiography was performed to all patients. Serum NT-proBNP, creatine kinase (CK), creatine kinase-MB (CK-MB), and troponin-T were also analyzed, along with the carboxyhemoglobin (COHb) level. The correlation between serum NT-proBNP and COHb level was investigated. Electrocardiography (ECG) was performed to all patients and healthy controls, and the results were compared. Differences in troponin, CK, and CK-MB levels were not statistically significant between groups (p > 0.05). The level of NT-proBNP and COHb were found to be increased in the study group. There was a positive correlation between the COHb and the NT-proBNP (r = 0.829, p < 0.01), and between the COHb and the CK (r = 0.394, p < 0.01). There was no difference between groups in other parameters, all of which were within normal range. Thus, in this sudy we showed that the plasma NT-proBNP level may contribute to the early diagnosis of cardiotoxicity in patients with carbon monoxide poisoning.

The effects of levobupivacaine versus levobupivacaine plus magnesium infiltration on postoperative analgesia and laryngospasm in pediatric tonsillectomy patients

BACKGROUND The aim of this study was to evaluate whether the addition of magnesium to levobupivacaine will decrease the postoperative analgesic requirement or not, and to investigate the possible preventive effects on laryngospasm. METHODS Seventy-five children undergoing elective tonsillectomy and/or adenoidectomy surgery. The drug was prepared as only NaCl 0.9% for the first group (Group S, n=25), levobupivacaine 0.25% for the second group (Group L, n=25), and levobupivacaine 0.25% plus magnesium sulphate 2mg/kg for the third group (Group M, n=25). Pain was recorded at 15th minute, 1st, 4th, 8th, 16th, and 24th hour postoperatively. Pain was evaluated using a modified Childrens Hospital of Eastern Ontario pain scale (mCHEOPS). Incidence of postoperative nausea and vomiting (PONV) was assessed at various time intervals (0-2, 2-6, 6-24h) by numeric rank score. Patients were followed for laryngospasm for 1h in recovery room after extubation. Other complications appeared within 24h postoperatively were recorded. RESULTS All postoperative CHEOPS values were lower than control in both groups. Analgesic requirement was decreased significantly in both groups in comparison with control patients, but this requirement was significantly lower in Group M (p<0.05). Although laryngospasm was not observed in Group M, the difference between groups was not statistically significant. PONV was similar in both groups. CONCLUSIONS Levobupivacaine and Levobupivacaine plus magnesium infiltration decrease the post-tonsillectomy analgesic requirement. Insignificant preventive effect of low doses of magnesium infiltration on laryngospasm observed in this study needs to be clarified by larger series.

Preconditionin effects of dexmedetomidine on myocardial ischemia/reperfusion injury in rats

BACKGROUND Preconditioning might protect the myocardium against ischemia/ reperfusion injury by reducing infarct size and preventing arrhythmias. Dexmedetomidine (DEX) is a highly selective α2-agonist used for sedoanalgesia in daily anesthetic practice. The cardioprotective effects of DEX on infarct size and on the incidence of arrhythmias observed after regional ischemia/reperfusion injury in vivo have not been reported. OBJECTIVE The aim of this study was to determine whether DEX exhibits a preconditioning effect and reduces infarct size and the incidence and duration of arrhythmias in a regional cardiac ischemia/reperfusion model in rats. METHODS Adult male Sprague-Dawley rats were anesthetized with sodium thiopental and mechanically ventilated (0.9 mL/100 g at 60 strokes/min) through a cannula inserted into the trachea after tracheotomy. Cardiac ischemia was then produced by ligating the left main coronary artery for 30 minutes, followed by a reperfusion period of 120 minutes. Blood pressure (BP) and heart rate (HR) were monitored and echocardiograms (ECGs) were performed. Arrhythmia was scored based on incidence and duration. The animals were randomly divided into 3 groups. The ischemic preconditioning (IPC) group underwent 5 minutes of ischemia followed by 5 minutes of reperfusion before the 30-minute ischemia/120-minute reperfusion period. In the DEX group, intraperitoneal (IP) DEX 1 mL (100 μg/kg) was administered 30 minutes before the ischemia/ reperfusion period. In the control group, IP saline 1 mL was administered 30 minutes before the ischemia/reperfusion period. After reperfusion, the heart was excised, demarcated with saline and ethanol to identify the occluded and nonoccluded myocardium, and cut into slices ~2 mm thick, that were then stained and placed between 2 glass plates. The risk zone and the infarct zone were compared between groups. The investigator assessing the infarcts was blinded to the study group. RESULTS Twenty-one adult (aged 4-6 months) male Sprague-Dawley rats weighing 280 to 360 g were included in the study; 7 rats were assigned to each group. BP, HR, and ECG readings were not significantly different between groups and did not change during the study. Arrythmias occurred during ischemia and reperfusion in all groups. The duration of the arrhythmias was significantly shorter and the arrhythmia score was significantly lower in the IPC group (all, P<0.05), compared with the control group; however, they were not significantly different in the DEX group. During the ischemic period, duration of ventricular tachycardia (VT) and ventricular premature contractions (VPC) in the DEX group was significantly longer than that observed in the IPC group (all, P<0.05). The duration of VPC was also significantly shorter than that observed in the control group (both, P<0.05). Duration of VT during the reperfusion period in the DEX group was significantly longer than that observed in both IPC and control groups (both, P<0.05). The mean (SD) percentage of damage was significantly lower in the IPC group (44.1% [2.0%]) and the DEX group (26.7% [2.0%]) compared with the control group (69.0% [3.0%]; both, P<0.05). The percentage of damage in the DEX group was also significantly lower compared with the IPC group (P<0.05). CONCLUSIONS This small, experimental in vivo study found that DEX was associated with reduced infarct size in ischemia/reperfusion injury in regional ischemia in this rat model but had no effect on the incidence of arrhythmias. Future studies are needed to clarify these findings.

Comparison of topical tramadol and ketamine in pain treatment after tonsillectomy.

The primary objective of this study is to evaluate the effects of topically applied ketamine or tramadol on early postoperative pain scores in children undergoing tonsillectomy. The secondary aim of the study is to assess nausea, vomiting, difficulty in swallowing, and sore throat characteristics of the patients.

Comparison of dexmedetomidine and midazolam for monitored anesthesia care combined with tramadol via patient-controlled analgesia in endoscopic nasal surgery: A prospective, randomized, double-blind, clinical study

UNLABELLED Abstract. BACKGROUND Monitored anesthesia care (MAC) may be applied for septoplasty or endoscopic sinus surgery in which an adequate sedation and analgesia without respiratory depression are desired for comfort of both the patient and the surgeon. Several combinations with different agents have been used for this purpose in these patients. However, analgesic properties for these agents have not been reported. OBJECTIVE The aim of this study was to investigate the analgesic and sedative effects of dexmedetomidine or midazolam infusion combined with tramadol that was used via patient-controlled analgesia (PCA), and to document the effects of these drugs on early cognitive functions. METHODS This prospective, randomized, double-blind, clinical study enrolled patients undergoing septoplasty or endoscopic sinus surgery at the Abant Izzet Baysal University Hospital, Bolu, Turkey, between February and September 2006. Patients were randomly allocated in a 1:1 ratio into 1 of 2 groups: the dexmedetomidine group (group D) patients received IV dexmedetomidine 1 μg/kg for 10 minutes followed by continuous infusion of 0.5 μg/kg · h(-1); and the midazolam group (group M) patients were administered a loading dose of IV midazolam 40 μg/kg for 10 minutes followed by infusion at the rate of 50 μg/kg · h(-1). A 1-minute bolus dose of IV tramadol (1.5 mg/kg) was administered in both groups 10 minutes after the administration of the primary drug, and continued via infusion using a PCA device. After baseline measurements, systolic arterial pressure (SAP), diastolic arterial pressure (DAP), mean arterial pressure (MAP), heart rate (HR), oxygen saturation, and rate of respiration were recorded after the loading dose of study drug, after the bolus tramadol dose, at 10-minute intervals during the operation, and twice in the recovery rooms; 5 minutes after arrival and 5 minutes before discharge. Verbal rating score (VRS) and Ramsay sedation score were determined at baseline (after surgery was started), every 10 minutes thereafter until the end of the operation, and 2 times during recovery. All patients were assessed with the Wechsler Memory Scale-Revised at baseline (preoperatively) and 4 hours after the operation. RESULTS Seventy patients were enrolled in the study and randomly assigned to 1 of 2 groups: group D (sex, male/female, 23/12; mean [SEM] age, 32.53 [2.07] years; mean [SEM] weight, 73.03 [2.41] kg) or group M (sex, male/female, 21/14; mean [SEM] age, 34.43 [1.83] years; mean [SEM] weight, 67.90 [2.32] kg). All hemodynamic parameters (SAP, DAP, MAP, HR) were significantly higher in group M compared with group D from the onset of the surgery to discharge time (P < 0.05). Pain and sedation scores were similar in both groups, but the amount of PCA-administered rescue tramadol was significantly higher in group M (P = 0.001). A higher, though not statistically significant, prevalence of adverse events (ie, hypotension, bradycardia, and perioperative nausea and vomiting) were observed in group D. Postoperative logical verbal memory and digit span values were significantly higher in group D when compared with group M (P < 0.05). Postoperative digit span and visual reproduction scores were significantly higher than preoperative values in group D (P < 0.05). Postoperative personality functioning scores were significantly higher than preoperative values in group M (P < 0.05). CONCLUSIONS Based on VRS, Ramsay sedation scores, and surgeon and anesthesiologist satisfaction scores, dexmedetomidine or midazolam combined with tramadol PCA provided adequate analgesia and sedation in these adult patients undergoing septoplasty or endoscopic sinus surgery with MAC. A significantly larger amount of rescue tramadol was used by group M, suggesting that a better analgesic effect was achieved with dexmedetomidine.

Comparison of lidocaine and levobupivacaine in transnasal fiberoptic laryngoscopy.

Background The anatomy of the nasal passages, pharynx, and larynx and evaluation of mucous membranes and laryngeal function is well observed by transnasal fiberoptic laryngoscopy (TFL). In this procedure, to provide good local infiltrative analgesia, medication such as anesthetics is important for the otolaryngologist. The aim of this study was to evaluate the efficacy of lidocaine (L) spray, compared with levobupivacaine solution, used for local anesthetic in patients undergoing TFL for complete examination. Methods Sixty-two subjects (39 men and 23 women; mean age, 36 ± 7 years) were enrolled in the study. Patients were randomly classified into two groups as levobupivacaine hydroclorur (LB) and L groups. A standard flexible transnasal fiberoptic 4.2-mm-diameter laryngoscope was passed through the nasal cavity and into the aerodigestive tract. Patients were asked to evaluate the intensity of the pain they experienced during the TFL, using a visual analog scale (VAS) and Ramsay sedation scale. Results Demographic data were similar in both groups. There was no difference in VAS and Ramsay res between bith groups (p > 0.05). Conclusion Our findings indicated that topical levobupivacaine seems to be an effective medication for anesthesia of the nasal mucosa and may be used to allow complete examinations involving TFL.

Effect of pregabalin and dexamethasone on postoperative analgesia after septoplasty.

Objectives. The aim of this study was to explore effect of a combination of pregabalin and dexamethasone on pain control after septoplasty operations. Methods. In this study, 90 patients who were scheduled for septoplasty under general anesthesia were randomly assigned into groups that received either placebo (Group C), pregabalin (Group P), or pregabalin and dexamethasone (Group PD). Preoperatively, patients received either pregabalin 300 mg one hour before surgery, dexamethasone 8 mg intravenously during induction, or placebo according to their allocation. Postoperative pain treatment included tramadol and diclofenac sodium 30 minutes before the end of the operation. Numeric rating scale (NRS) for pain assessment, side effects, and consumption of tramadol, pethidine, and ondansetron were recorded. Results. The median NRS score at the postoperative 0 and the 2nd h was significantly higher in Group C than in Group P and Group PD (P ≤ 0.004 for both). The 24 h tramadol and pethidine, consumptions were significantly reduced in Groups P and PD compared to Group C (P < 0.001 and P < 0.001). The incidence of blurred vision was significantly higher in Group PD compared to Group C within both 0–2 h and 0–24 h periods (P = 0.002 and P < 0.001, resp.). Conclusions. We conclude that administration of 300 mg pregabalin preoperatively may be an adequate choice for pain control after septoplasty. Addition of dexamethasone does not significantly reduce pain in these patients.

The Effect of Prilocaine or Levobupivacaine Infiltration on Pain during Nasal Packing Removal

Objective. The aim of this study was to evaluate the efficacy of rehydration of Merocel nasal packs with prilocaine or levobupivacaine on reducing pain and discomfort of nasal packing removal in patients who had undergone septoplasties or endoscopic sinus surgery. Study Design. Prospective clinical study. Setting. Tertiary referral center. Methods. This prospective study was conducted on 72 patients, aged 18 to 55 years, who had undergone septoplasty, bilateral functional endoscopic sinus surgery, or both. The patients were divided into 2 groups: prilocaine group (group P, n = 36), who received 2.5 mL of 2% prilocaine, and levobupivacaine group (group L, n = 36), who received 2.5 mL of levobupivacaine hydrochloride dilution. These solutions were diluted with 2.5 mL saline to a final volume of 5 mL, which was then injected into the Merocel packing 15 minutes before removal of the pack. In both groups, 5 mL of saline was injected into the packing in the contralateral nostril as a control 15 minutes before removal of the pack. Visual analog score (VAS) and the Ramsay sedation score were recorded. Results. Statistically significant differences were found in VAS and Ramsay sedation scale scores of levobupivacaine and prilocaine groups compared to controls. No significant difference was noted between the groups in terms of levobupivacaine and prilocaine. Conclusions. Levobupivacaine or prilocaine infiltration before removal of nasal packs in patients who undergo septoplasties or endoscopic sinus surgery can decrease discomfort and improve patient tolerability.

Two different doses of caudal neostigmine co-administered with levobupivacaine produces analgesia in children

Background:  This study was aimed to evaluate the analgesic efficacy, duration of analgesia, and side effects of two different doses of caudal neostigmine used with levobupivacaine in children.