The alpha-2 receptor agonist dexmedetomidine attenuates vancomycin­induced acute kidney injury.

OBJECTIVE: This study was conducted to evaluate the protective effect of dexmedetomidine on nephrotoxicity and the mechanism of renoprotection following vancomycin-induced nephrotoxicity in rats. METHODS: Thirty-two albino Wistar rats were divided into four groups. The control group received intraperitoneal (IP) physiological saline solution, the vancomycin (VMC) group received IP 200 mg/kg vancomycin, the dexmedetomidine (DEX) group received IP 5 µg/kg dexmedetomidine, and the vancomycin and dexmedetomidine (VMC+DEX) group received IP 200 mg/kg vancomycin followed by IP 5 µg/kg dexmedetomidine 20 min after the vancomycin injection. On the 8th day of the experiment, histopathological and biochemical parameters were assessed. RESULTS: Creatinine levels were significantly higher in VMC and VMC+DEX groups. The endothelin-1 level was significantly higher in VMC group. Nitric oxide levels were statistically lower in VMC and VMC+DEX groups. Histopathologic assessments revealed that the extent of renal damage was significantly higher in group VMC (n = 4 with damage of Grade 3) compared to group VMC+DEX (n = 0 with damage of Grade 3). CONCLUSION: It was determined that dexmedetomidine can reduce the extent of renal damage by preventing the elevation of vasoconstrictor agents (Tab. 2, Fig. 1, Ref. 36).

Tetanus in adults: results of the multicenter ID-IRI study.

Tetanus is an acute, severe infection caused by a neurotoxin secreting bacterium. Various prognostic factors affecting mortality in tetanus patients have been described in the literature. In this study, we aimed to analyze the factors affecting mortality in hospitalized tetanus patients in a large case series. This retrospective multicenter study pooled data of tetanus patients from 25 medical centers. The hospitals participating in this study were the collaborating centers of the Infectious Diseases International Research Initiative (ID-IRI). Only adult patients over the age of 15 years with tetanus were included. The diagnosis of tetanus was made by the clinicians at the participant centers. Izmir Bozyaka Education and Research Hospital's Review Board approved the study. Prognostic factors were analyzed by using the multivariate regression analysis method. In this study, 117 adult patients with tetanus were included. Of these, 79 (67.5%) patients survived and 38 (32.5%) patients died. Most of the deaths were observed in patients >60 years of age (60.5%). Generalized type of tetanus, presence of pain at the wound area, presence of generalized spasms, leukocytosis, high alanine aminotransferase (ALT) and C-reactive protein (CRP) values on admission, and the use of equine immunoglobulins in the treatment were found to be statistically associated with mortality (p < 0.05 for all). Here, we describe the prognostic factors for mortality in tetanus. Immunization seems to be the most critical point, considering the advanced age of our patients. A combination of laboratory and clinical parameters indicates mortality. Moreover, human immunoglobulins should be preferred over equine sera to increase survival.

The effects of intraoperative infusion of dexmedetomidine on early renal function after percutaneous nephrolithotomy.

BACKGROUND: Percutaneous nephrolithotomy (PCNL) may interfere with renal function because of continuous fluid irrigation and compression. The aim of this study was to evaluate the effects of an intraoperative infusion of dexmedetomidine on renal function in patients undergoing PCNL. METHODS: This study included 40 patients between the ages of 18 and 65 years who underwent PCNL. After induction of anesthesia, we administered 100 ml of normal saline to the patients in the control group (n=20) and 1 mcg/kg dexmedetomidine in 100 ml of normal saline to the patients in the dexmedetomidine group (n=20) over 10 min. Throughout the surgery, 1 mcg/kg/h dexmedetomidine and 1 ml/kg/h normal saline infusions were given to the dexmedetomidine and control groups, respectively. Renal function, electrolytes, serum levels of neutrophil gelatinase-associated lipocalin (NGAL) and cystatin C were analyzed after induction and post-operatively at 2, 8 and 24 h. Renin levels and blood gas analyses were performed after induction and before extubation. RESULTS: No statistically significant differences were found between the two groups with regard to renal function, creatinine clearance (CrCl), NGAL, cystatin C and serum electrolyte levels at 0, 2, 8 and 24 h post-operatively. End-surgery renin levels in the dexmedetomidine group were significantly lower than the baseline levels in the control group. CONCLUSION: In PCNL, an intraoperative infusion of dexmedetomidine was not found to have beneficial effects on CrCl, NGAL or cystatin C levels early after the procedure; however, it reduced renin levels.

Dexmedetomidine and meperidine prevent postanaesthetic shivering.

BACKGROUND AND OBJECTIVE: This placebo-controlled study was performed to evaluate the efficacy of dexmedetomidine compared with meperidine and placebo in preventing postanaesthetic shivering. METHODS: We studied 120 patients (ASA I-II) scheduled for elective abdominal or orthopaedic surgery of about 1-3 h duration. Forty patients in each group randomly received 1 microg kg(-1) of dexmedetomidine, 0.5 mg kg(-1) of meperidine or saline 0.9% as placebo, intravenously (i.v.). Mean arterial pressure, heart rate, oxygen saturation and central body temperature were measured. Extubation, awakening and orientation times, shivering, pain, recovery and sedation scores were recorded. RESULTS: Postanaesthetic shivering was seen in 22 patients in the placebo group, four patients in the meperidine group and six patients in the dexmedetomidine group. Sedation scores were significantly higher in the dexmedetomidine group compared with meperidine and placebo groups. Both dexmedetomidine and meperidine caused a significantly prolonged extubation and awakening time compared with placebo. Also, dexmedetomidine caused a significantly prolonged orientation time compared with other two groups. CONCLUSION: Intraoperative intravenously administration of dexmedetomidine 1 microg kg(-1) reduces postanaesthetic shivering as does meperidine 0.5 mg kg(-1) in patients after major surgery.

Desflurane anaesthesia increases sister chromatid exchanges in human lymphocytes.

BACKGROUND: We investigated genotoxic effects of desflurane on the frequency of sister chromatid exchange (SCE) in peripheral blood lymphocytes of patients during and after anaesthesia. METHODS: Fifteen female patients, ASA classification I-II, aged 26-54 years, undergoing elective surgery were enroled in this study. Anaesthesia was induced by injection of thiopental 5-7 mg/kg and fentanyl 1 microg/kg. Vecuronium 0.1 mg/kg was given to facilitate tracheal intubation. Anaesthesia was maintained with desflurane 5-6% in an oxygen/air mixture (FiO(2) 0.3). N(2)O was not used for any patient. Using a heparinized syringe, venous blood was collected in patients before anaesthesia. Additional venous blood samples were taken from all patients at 60 and 120 min after the initiation of anaesthesia. Post-operative blood samples were taken and first, third, seventh and twelfth day samples were coded. RESULTS: Number of SCEs per cell at 60 and 120 min were significantly higher than the number of SCEs per cell before anaesthesia. In addition, number of SCEs per cell at 1, 3 and 7th post-operative days were significantly higher than pre-operative levels (P < 0.05). There was no difference between pre-operative number of SCEs per cell and 12th post-operative day levels (P > 0.05). CONCLUSION: In the present study, because exposure to desflurane increased sister chromatid exchange in human lymphocytes in our group of patients, we conclude that this agent may be capable of producing genetic damage.

Addition of dexmedetomidine to lidocaine for intravenous regional anaesthesia.

BACKGROUND AND OBJECTIVE: The aim of this study was to determine the duration of onset and regression time of sensory and motor blocks, the quality of anaesthesia and postoperative analgesia by the addition of dexmedetomidine to local anaesthetic solution in intravenous regional anaesthesia (IVRA). METHODS: Forty patients scheduled for elective hand surgery participated in this prospective randomized double-blind study. The IVRA was achieved using 3 mg kg(-1) lidocaine diluted with saline to a total volume of 40 mL in the control group or 1 microg kg(-1) of dexmedetomidine + 3 mg kg(-1) lidocaine diluted with saline to a total volume of 40 mL in the dexmedetomidine group. The onset and regression times for sensory and motor blocks were recorded. Qualities of anaesthesia, intraoperative and postoperative analgesic requirements were noted. RESULTS: There was no difference between the groups with respect to sensory and motor blocks onset and regression time. The quality of anaesthesia was better in the dexmedetomidine group than the control group and the difference was statistically significant. Intraoperative and postoperative analgesic requirements were greater in the control group than in the dexmedetomidine group. CONCLUSIONS: Addition of dexmedetomidine to local anaesthetic solution in IVRA improved the quality of anaesthesia and decreased analgesic requirements, but had no effect on the sensory and motor blocks onset and regression times.

Propofol and propofol-ketamine in pediatric patients undergoing cardiac catheterization.

We investigated the effects of propofol and propofol-ketamine on hemodynamics, sedation level, and recovery period in pediatric patients undergoing cardiac catheterization. We performed a prospective, randomized, double-blind study. The study included 60 American Society of Anesthesiologists physical status II or III (age range, 1 month-13 years) undergoing cardiac catheterization for evaluation of congenital heart disease. Propofol and ketamine were prepared in 5% glucose solution to a final concentration of 5 and 1 mg/ml, respectively; similar injectors containing 5% glucose solution only were prepared. Fentanyl (1 microg/kg) and propofol (1.5 mg/kg) were given to both groups. Then, group 1 received 0.5 ml/kg of 5% glucose and group 2 0.5 ml/kg of ketamine solution by an anesthesiologist who was unaware of the groups of patients. Local anesthesia with 1% lidocaine was administered before intervention in all patients. The noninvasively measured mean arterial pressure, heart rate, respiratory rate, and peripheral oxygen saturation were recorded at the baseline, following drug administration, at 3, 5, 10, 15, 20, and 30 minutes and then at 15-minute intervals until the end of the procedure. Additional drug and fentanyl requirements to maintain a sedation level of 4 or 5 were recorded. After the procedure, the time to a Steward recovery score of 6 and adverse effects in the first 24 hours were recorded. The number of patients with more than a 20% decrease in mean arterial pressure was 11 in group 1 and 3 in group 2 (p < 0.05). The number of patients who experienced more than a 20% decrease in heart rate was 12 in group 1 and 5 in group 2 (p = 0.054). Ten patients in group 1 and 3 patients in group 2 required additional fentanyl doses (p = 0.057). The number of additional propofol doses was lower in group 2 (p < 0.05). Propofol combined with low-dose ketamine preserves mean arterial pressure better without affecting the recovery and thus is a good option in pediatric patients undergoing cardiac catheterization.

Ephedrine enhances analgesic effect of morphine.

Morphine-ephedrine interaction on analgesia was studied in mice (n = 240) and in post-operative patients (n = 32). It was found that combining morphine and ephedrine enhances analgesia which is not significantly different from the effect of morphine given alone at double dose.

Pre-emptive efficacy of epidural fentanyl in elective abdominal surgery.

BACKGROUND AND AIM: This study determines whether epidural fentanyl given before incision decreases the requirements for opioid analgesia postoperatively, compared with the same dose of epidural fentanyl given after the surgery. METHODS: Forty patients scheduled to undergo elective abdominal surgery were randomly allocated between two groups according to the time of administered of fentanyl. None of the patients in either group received premedication. Prior to induction of general anaesthesia an epidural catheter was inserted at the L2-3 interspace and flushed with 0.9% NaCl. Patients then received 100 micrograms fentanyl in 10 mL 0.9% NaCl through this catheter either 15 min before awaking at the end of the operation (group I), or else the same dose given at an estimated time of 15 min before the start of surgery (group II). Postoperative analgesia consisted of patient-controlled intravenous fentanyl. The amount of fentanyl used by the patients was noted at 2, 4, 8, 12 and 24 h after surgery. Pain scores and sedation scores were assessed at 0, 2, 4, 8, 12 and 24 h postoperatively. RESULTS: The consumption of fentanyl was similar in both groups in all studied periods postoperatively. The mean pain score was lower for patients in group I than group II immediately after operation. There were no statistically significant differences between the mean pain scores of groups at 2, 4, 8, 12 and 24 h after operation. Mean sedation scores were similar in both groups at all times postoperatively. CONCLUSION: This study showed that the dose of fentanyl administered epidurally prior to surgical incision did not produce any clinically useful pre-emptive analgesic effect.

Unilateral spinal anaesthesia with hyperbaric bupivacaine.

BACKGROUND: The dosage of local anaesthetic and the time the patient must be kept in the lateral decubitus position for a unilateral spinal anaesthesia is not known. The aim of this study was to determine the ideal dosage of hyperbaric bupivacaine and the time required for the lateral decubitus position for a unilateral spinal block. METHODS: Ninety patients who were scheduled to receive spinal block for surgery in the lower extremity were randomised into 9 groups (n = 10). The spinal block was performed through the L4-L5 intervertebral space with the patient in the lateral decubitus position. Patients in groups Ia, Ib, Ic; IIa, IIb, IIc; IIIa, IIIb, IIIc received 1.5 ml of 0.5%, 2 ml of 0.5%, and 2.5 ml of 0.5% hyperbaric bupivacaine solutions, respectively. The patients were turned to the supine position for 5 min after the injection in groups Ia, IIa, IIIa, 10 min after the injection in groups Ib, IIb, IIIb, and 15 min after the injection in groups Ic, IIc, IIIc. The onset and regression of sensory and motor block were checked and compared between the dependent and non-dependent sides in each group. RESULTS: The rate of block progression of the non-dependent side was higher in the groups receiving 2.5 ml 0.5% hyperbaric bupivacaine solution than in the other groups; at the same time the level of block was higher and the duration of block was longer. The incidence of hypotension was 10-20% in these groups. In the 2 ml 0.5% hyperbaric bupivacaine solution groups, a satisfactory block level and duration of anaesthesia for surgery was obtained. The rate of block progression to non-dependent side in the groups receiving 1.5 ml of 0.5% hyperbaric bupivacaine solution was lower than the other groups, but the duration of block was shorter and the level of block was lower than the other groups. CONCLUSION: For unilateral spinal anaesthesia in lower extremity operations, 2ml 0.5% hyperbaric bupivacaine solution for operations above the knee and 1.5 ml 0.5% hyperbaric bupivacaine solution for operations below the knee and keeping the patients for 10 min in the lateral decubitus position were found to be appropriate.