Senem Koruk

Ultrasound-guided infraclavicular brachial plexus block enhances postoperative blood flow in arteriovenous fistulas

OBJECTIVE Brachial plexus block offers several advantages when creating vascular access for hemodialysis. However, no controlled studies have directly evaluated arteriovenous fistula (AVF) blood flow in patients anesthetized by this method. We compared the effects of ultrasound-guided, infraclavicular brachial plexus block and local infiltration anesthesia on blood flow in the radial artery and AVF during the early and late postoperative periods. METHODS Sixty patients were randomly assigned to an experimental group, which received infraclavicular brachial plexus block (IB), or to a control (C) group that received local infiltration anesthesia. Blood flow in the distal radial artery was measured before and after IB or infiltration anesthesia. AVF flow during the early and late postoperative period was evaluated using duplex ultrasound imaging. The rates of primary fistula failure were also compared. RESULTS After anesthesia, preoperative radial arterial flow was 56 ± 8.6 mL/min in group IB vs 40.7 ± 6.11 mL/min in group C (P < .0001). Blood flow in the fistula, measured in mL/min at 3 hours, 7 days, and 8 weeks postoperatively, was also greater in group 1B vs group C, respectively, at 69.6 ± 7.9 vs 44.8 ± 13.8 (P < .001), 210.6 ± 30.9 vs 129 ± 36.1 (P < .001), and 680.6 ± 96.7 vs 405.3 ± 76.2 (P < 0.001). CONCLUSION When used for AVF access surgery, infraclavicular brachial plexus block provides higher blood flow in the radial artery and AVF than is achieved with infiltration anesthesia.

Propofol/Dexmedetomidine and Propofol/Ketamine Combinations for Anesthesia in Pediatric Patients Undergoing Transcatheter Atrial Septal Defect Closure: A Prospective Randomized Study

BACKGROUND Children undergoing cardiac catheterization usually need general anesthesia or deep sedation. OBJECTIVE This study was performed to compare the effects of propofol/dexmedetomidine and propofol/ketamine combinations on recovery time and hemodynamic parameters in pediatric patients undergoing transcatheter atrial septal defect (ASD) closure. METHODS This was a prospective randomized study. Pediatric patients with ASD were randomly assigned into 2 groups to receive propofol/dexmedetomidine or propofol/ketamine. The dexmedetomidine group received an infusion over 10 minutes of dexmedetomidine 1 microg/kg and propofol 2.0 to 2.5 mg/kg bolus for induction, then an infusion of dexmedetomidine 0.5 microg/kg/h and propofol 4 to 6 mg/kg/h for maintenance. In the ketamine group, patients received the same dose of propofol and ketamine 1 mg/kg for induction and 0.5 mg/kg/h by infusion for maintenance. The procedure was performed using both fluoroscopy and transesophageal echocardiography. Hemodynamic data, respiratory rate, and oxygen saturation were recorded before and after induction, 1 and 5 minutes after intubation, every 10 minutes thereafter during the procedure, and after extubation by researchers blinded to the study drugs. Recovery time, the primary outcome, was evaluated by a modified Steward score; a score of >or=6 means that the patient is awake or responds to verbal stimuli, has purposeful motor activity, and coughs on command. The time to reach a modified Steward score of >or=6 was recorded. The secondary outcome was the effects on the hemodynamic variables. Creatine kinase muscle-brain subunit, myoglobin, cardiac troponin I, and brain natriuretic peptide were the biochemical variables measured. Patients were monitored for respiratory (changes in oxygen status) and hemodynamic adverse effects (heart rate changes, blood pressure changes) until the second hour in the intensive care unit after the operation was concluded. RESULTS Nine patients each were randomly assigned to propofol/dexmedetomidine and propofol/ketamine. The demographic and clinical parameters were not significantly different between groups. In the dexmedetomidine group, 5 of the patients were male, mean (SD) age was 12.5 (10.4) years, and mean weight was 40.8 (27.8) kg. In the ketamine group, 3 patients were male, mean age was 10.1 (4.5) years, and mean weight was 30.0 (15.2) kg. The recovery time was significantly longer in the ketamine group than in the dexmedetomidine group (10.5 [3.4] vs 5.7 [0.8] minutes; P = 0.01). Systolic and diastolic blood pressure values were not significantly different between groups in any study period. Heart rate values were significantly higher in the ketamine group at 5 minutes after intubation (106.6 vs 84.2 beats/min), 10 minutes (111.8 vs 87.4 beats/min) and 30 minutes (110.0 vs 89.6 beats/min) perioperatively, and after extubation (126.8 vs 92.2 beats/min) (all, P < 0.05). In the dexmedetomidine group, one patient experienced shivering and one reported nausea; in the ketamine group, one patient reported nausea. Neither respiratory depression nor severe hypotension (ie, >20% change over baseline or requiring intervention) was observed in any patient. One patient developed agitation in the ketamine group. CONCLUSIONS In this small study, both dexmedetomidine and ketamine in combination with propofol were well tolerated in these pediatric patients who required ASD closure. The recovery period was significantly shorter in the dexmedetomidine group.

Pretreatment with Dexmedetomidine or Thiopental Decreases Myoclonus after Etomidate: A Randomized, Double-Blind Controlled Trial

BACKGROUND Myoclonic movements are common problems during induction of anesthesia with etomidate. The aim of this study was to compare the effect of pretreatment with dexmedetomidine (0.5 microg/kg) and thiopental (1 mg/kg) on the incidence of etomidate-induced myoclonus and postoperative pain. MATERIALS AND METHODS A prospective double-blind study was conducted at a university hospital. Ninety patients (ASA physical status I-II) were randomly assigned to one of three groups: patients were pretreated with either dexmedetomidine (0.5 microg/kg), thiopental (1 mg/kg), or saline before induction of anesthesia with etomidate. One minute after the injection of study drugs, etomidate, 0.3 mg/kg was given. Myoclonus was assessed on a scale of 0 to 3. Recovery time, postoperative pain score, and hemodynamic variables were recorded during the intraoperative and postoperative period. Headache, nausea, vomiting, and coughing were noted during the study. RESULTS The incidence and the intensity of myoclonus was significantly lower in the dexmedetomidine and thiopental groups (34%, 36%) than in the control group (64%) (P<0.05). The postoperative pain score at 30 min in the thiopental group was significantly higher than in the dexmedetomidine and control groups (63%) (P<0.05). CONCLUSIONS We concluded that pretreatment with dexmedetomidine or thiopental is effective in reducing the incidence and severity of etomidate-induced myoclonic muscle movements and pretreatment with thiopental increases the postoperative pain.

Premedication with dexmedetomidine and midazolam attenuates agitation after electroconvulsive therapy.

PurposeThis study was designed to compare the effects of premedication with dexmedetomidine and midazolam on post-electroconvulsive therapy (ECT) agitation (which patients had experienced previously and had been resistant to treatment). In addition, we aimed to evaluate the duration of convulsion, the propofol requirement, the recovery time, and patients’ satisfaction during and after ECT.MethodsFifteen patients with depressive episodes of bipolar disorder and nonbipolar recurrent depression and patients who underwent a series of three consecutive ECT treatments were studied as a crossover design. In this double-blind and placebo-controlled study, patients were randomly allocated to receive either dexmedetomidine, 0.5 μg·kg−1 (group Dex), midazolam, 0.025 mg·kg−1 (group Dor), or saline (group C) in a total volume of 20 ml given intravenously 10 min before the induction of anesthesia. Propofol was administered until the patients did not respond to a verbal command.ResultsThe mean duration of convulsive activity was longer in group Dex than in group C and group Dor (P < 0.05). The total dose of propofol requirement in group Dor and group Dex was lower than that in group C (P < 0.05). Agitation scores in both groups Dor and Dex were significantly lower than scores in group C (P < 0.05) at 10 and 15 min after ECT.ConclusionPremedication with low-dose intravenous dexmedetomidine, 0.5 μg·kg−1 or midazolam, 0.025 mg·kg−1 before ECT may be useful in managing treatment-resistant agitation after ECT, without adverse effects.

P-wave dispersion between transcatheter and surgical closure of secundum-type atrial septal defect in childhood

Patients with atrial septal defect have an increased risk for atrial fibrillation. Increased P-wave dispersion predicts the development of atrial fibrillation. The aim of this study was to determine difference in P dispersion between transcatheter closure with Amplatzer septal occluder and surgical closure in childhood. A total of 68 children (the mean age was 7.2 plus or minus 3.3 years; the mean secundum atrial septal defects diameter was 17.3 plus or minus 5.4 millimetres) were evaluated in this study. Transcatheter closure was attempted in 41 children with secundum atrial septal defects, and the defect in 27 patients was closed by surgical techniques. P maximum, P minimum and P dispersion were measured by the 12-lead surface electrocardiography. P maximum, P minimum and P dispersion were found to be similar in patients with pre- and post-procedure (98.0 plus or minus 19.3 versus 95.1 plus or minus 23.0 milliseconds; 68.0 plus or minus 20.8 versus 67.6 plus or minus 24.3 milliseconds, 29.9 plus or minus 11.0 versus 27.1 plus or minus 12.1 milliseconds, respectively). There was no statistical significance in the comparison of P dispersion between the two groups. But in the surgical group, P-wave dispersion was decreased more significantly compared with baseline values (p-value equal to 0.03). In conclusion, there is no P dispersion between transcatheter closure with Amplatzer septal occluder and surgical closure of secundum atrial septal defect.

The Effects of Dexmedetomidine on Ischemia Reperfusion Injury in Patients Undergoing Arthroscopy Under Spinal Anesthesia

OBJECTIVE Ischemia and reperfusion injury due to tourniquet application during arthroscopy is a well known problem. This study aimed to compare the effects of dexmedetomidine and ketamine on hemodynamic and respiratory variables and on total anti-oxidant status (TAS), total oxidant status (TOS) and malondialdehyde (MDA) as markers of ischemia-reperfusion injury. MATERIALS AND METHODS This study was approved by a local ethics committee. The study was performed on patients undergoing arthroscopic operation under spinal anesthesia. Thirty patients were randomized into two groups: Group D (dexmedetomidine; n=15) and Group K (Ketamine; n=15). Spinal anesthesia at the L2-4 level was achieved using a 25G spinal needle with hyperbaric bupivacaine at a dose of 12-15 mg in all patients. In Group D, patients were sedated with dexmedetomidine at a dose of 0.3-0.5 μg/kg/h, while Group K received ketamine at a dose of 1-1.5 mg/kg/h. Hemodynamic parameters, oxygen saturation, Ramsey sedation scale (RSS), and TAS, TOS, and MDA levels were recorded. RESULTS Demographic parameters, TAS, TOS and MDA levels were similar between groups. In Group K, the TOS levels after tourniquet removal were significantly lower than at baseline and during the use of the tourniquet. Preoperative hemodynamic and respiratory variables were similar in both groups. Blood pressure values were decreased compared to baseline but these decreases were not statistically significant. CONCLUSION In patients undergoing arthroscopy under spinal anesthesia, dexmedetomidine had effects similar to ketamine, led to insignificant alterations in hemodynamic and respiratory variables during surgery and had comparable effects on ischemia-reperfusion injury. Thus, we think that dexmedetomidine can be a safe alternative to ketamine as an intraoperative sedative.

Comparison of the coaxial circle circuit with the conventional circle circuit.

OBJECTIVE The coaxial circle system helps prevent heat loss during surgery, and it also acts as a humidifier. This study aimed to compare the coaxial breathing system and the conventional system in their ability to warm and moisturize inhaled gases, and we also analyzed lung function protection and saccharin clearance time in patients who underwent tympanomastoidectomy (TMT) with the aid of these two systems. MATERIALS AND METHODS Forty adult patients of ASA physical status I-II were scheduled for elective TMT. A standard volume-dependent ventilator setting was used to establish normocapnia. The coaxial circle system was used in the treated group (n=20), whereas the conventional circuit system was used in the control group (n=20). Saccharin clearance, VC (vital capacity), FRC (functional residual capacity), FEV1 (forced expiratory volume in 1 second), airway pressure, relative humidity and temperature of inspired gas, body temperature and adverse and hemodynamic effects were measured at different perioperative periods. RESULTS The relative humidity (mg H2O Lt -1) of inspired gas in the treated group was higher than in the control group at 5, 15, 30, 45, 60 and 90 minutes after anesthesia induction. The temperature of inspired gas (Centigrade) in the treated group was higher than in the control group (p<0.05) after 5, 10, 15, 30, 45, and 90 minutes of anesthesia. Postoperative saccharin clearance time was lower than before the operation in the treated group (p<0.05). Postoperative FRC was lower than preoperative FRC in the study and control groups (p<0.05). CONCLUSION The coaxial circle system decreased postoperative saccharin clearance time and increased postoperative FRC, relative humidity and the temperature of inspired fresh gas, without any adverse perioperative effects in patients who underwent TMT.

Dexmedetomidine in the supratentorial craniotomy.

OBJECTIVE In this double-blind prospective clinical study, we investigated the effects of fentanyl and dexmedetomidine as adjuvant agents in supratentorial craniotomies on the following: hemodynamic changes during perioperative and recovery periods, brain edema perioperatively, recovery times and side effects, such as hypertension, shivering, nausea and vomiting. MATERIALS AND METHODS Thirty consenting ASA physical status I-II patients undergoing intracranial tumor surgery were randomly divided in two groups. In group D (n=15), dexmedetomidine was infused as a 1 μg/kg bolus dose 10 minutes before induction of anesthesia and maintained with 0.4-0.5 μg/kg/min during the operation. In group F (n=15), animals were given fentanyl 0.02 μg/kg/min as an infusion for anesthesia maintenance. At induction, fentanyl was given as a 2 μg/kg dose in group D and as a 4 μg/kg dose in group F. Hemodynamic changes, recovery times and postoperative side effects were recorded before induction, during the perioperative period and 24 hours postoperatively. RESULTS In group D; MAP and HR values after intubation, after skull clamp insertion and after extubation were lower than in group F (p<0.05). In group D, cerebral relaxation scores were also significantly lower. Recovery times were found to be shorter in group D as compared to group F; the same trend was observed for the supplemental opioid requirement. During the postoperative period, there was no shivering, nausea or vomiting in group D, but in group F, 3 patients complained of shivering, and 2 patients experienced nausea and vomiting. CONCLUSION In our study, we found that dexmedetomidine controlled the hemodynamic changes better than fentanyl perioperatively, after extubation and during the early postoperative period. Our results suggest that that dexmedetomidine is safer and more effective in controlling hemodynamic changes during surgical stimulation than the standard agents used in neuroanesthesia.

Leiomyosarcoma protruding into the left ventricle during diastole: report of a case.

Cardiac leiomyosarcoma is a rare tumor with poor survival prospects. Surgery prolongs survival, but the tumor often recurs early after surgery. The diagnosis is often made by transthoracic echocardiography. Magnetic resonance imaging and computed tomography are required to characterize the location and extent of cardiac masses. In this report, we present a patient with a leiomyosarcoma that was resected completely. The tumor was located in the left atrium, mimicked a myxoma, and protruded into the left ventricle during diastole.