Işıl Özkoçak Turan

Effect of Dexmedetomidine on Testicular Torsion/Detorsion Damage in Rats

Background and Objective: We assessed the antioxidant activity of dexmedetomidine (DEX) during an ischemic period in a rat model of testicular torsion/detorsion (T/DT) by using biochemical and histopathological methods. Methods: Wistar Albino male rats weighing 250–300 g were divided into three groups: sham (group S, n = 7); torsion/detorsion (group T/DT, n = 7), and DEX treatment (group DEX, n = 7). In the T/DT group, right testes were rotated 720° for 1 h. Group S served for normal basal values. Rats in group T/DT were operated to make T/DT, this group served as a control group. Group DEX received intraperitoneal DEX 10 µg · kg–1 after the 30-min torsion period. For measurement of total antioxidant enzyme activities and malondialdehyde (MDA) levels, testes of 7 animals in each group were excised after 4 h of reperfusion. Germ cell apoptosis was evaluated using the apoptosis protease-activating factor 1 (APAF-1) antibody in all groups and also on the expressions of endothelial nitric oxide synthase (eNOS) and inducible nitric oxide synthase (iNOS) were assessed within the bilateral testes. Results: Mean MDA levels in group T/DT were significantly higher than in groups S and DEX (p < 0.05). There were also significant decreases in mean total antioxidant activities in group T/DT when compared to groups S and DEX (p < 0.05). These values were significantly higher in group DEX than group T/DT. Germ cell apoptosis, eNOS and iNOS levels were significantly higher in group T/DT when compared to groups S and DEX (p < 0.05). Conclusions: DEX treatment has potential biochemical and histopathological benefits by preventing ischemia/reperfusion-related cellular damage in an experimental testicular torsion model. Preference of DEX for anesthesia during the detorsion procedure may attenuate ischemia-reperfusion injury.

Effects of Fentanyl-lidocaine-propofol and Dexmedetomidine-lidocaine-propofol on Tracheal Intubation Without Use of Muscle Relaxants

The aim of this study was to compare the effects of fentanyl or dexmedetomidine when used in combination with propofol and lidocaine for tracheal intubation without using muscle relaxants. Sixty patients with American Society of Anesthesiologists stage I risk were randomized to receive 1 mg/kg dexmedetomidine (Group D, n = 30) or 2 mg/kg fentanyl (Group F, n = 30), both in combination with 1.5 mg/kg lidocaine and 3 mg/kg propofol. The requirement for intubation was determined based on mask ventilation capability, jaw motility, position of the vocal cords and the patients response to intubation and inflation of the endotracheal tube cuff. Systolic arterial pressure, mean arterial pressure, heart rate and peripheral oxygen saturation values were also recorded. Rate pressure products were calculated. Jaw relaxation, position of the vocal cords and patients response to intubation and inflation of the endotracheal tube cuff were significantly better in Group D than in Group F (p < 0.05). The intubation conditions were significantly more satisfactory in Group D than in Group F (p = 0.01). Heart rate was significantly lower in Group D than in Group F after the administration of the study drugs and intubation (p < 0.05). Mean arterial pressure was significantly lower in Group F than in Group D after propofol injection and at 3 and 5 minutes after intubation (p < 0.05). After intubation, the rate pressure product values were significantly lower in Group D than in Group F (p < 0.05). We conclude that endotracheal intubation was better with the dexmedetomidine–lidocaine–propofol combination than with the fentanyl–lidocaine–propofol combination. However, side effects such as bradycardia should be considered when using dexmedetomidine.

Protective effect of dexmedetomidine in a rat model of α-naphthylthiourea–induced acute lung injury

BACKGROUND We assessed the effects of dexmedetomidine in a rat model of α-naphthylthiourea (ANTU)-induced acute lung injury. METHODS Forty Wistar Albino male rats weighing 200-240 g were divided into 5 groups (n = 8 each), including a control group. Thus, there were one ANTU group and three dexmedetomidine groups (10-, 50-, and 100-μg/kg treatment groups), plus a control group. The control group provided the normal base values. The rats in the ANTU group were given 10 mg/kg of ANTU intraperitoneally and the three treatment groups received 10, 50, or 100 μg/kg of dexmedetomidine intraperitoneally 30 min before ANTU application. The rat body weight (BW), pleural effusion (PE), and lung weight (LW) of each group were measured 4 h after ANTU administration. The histopathologic changes were evaluated using hematoxylin-eosin staining. RESULTS The mean PE, LW, LW/BW, and PE/BW measurements in the ANTU group were significantly greater than in the control groups and all dexmedetomidine treatment groups (P < 0.05). There were also significant decreases in the mean PE, LW, LW/BW and PE/BW values in the dexmedetomidine 50-μg/kg group compared with those in the ANTU group (P < 0.01). The inflammation, hemorrhage, and edema scores in the ANTU group were significantly greater than those in the control or dexmedetomidine 50-μg/kg group (P < 0.01). CONCLUSION Dexmedetomidine treatment has demonstrated a potential benefit by preventing ANTU-induced acute lung injury in an experimental rat model. Dexmedetomidine could have a potential protective effect on acute lung injury in intensive care patients.

The effects of dexmedetomidine dosage on cerebral vasospasm in a rat subarachnoid haemorrhage model.

We investigated the effect of two different doses of dexmedetomidine on vasospasm in a rat model of subarachnoid haemorrhage (SAH). SAH was induced by injecting 0.3 mL blood into the cisterna magna in all rat groups except the control (Group C). At 1 hour and 24 hours after SAH, 5 microg/kg dexmedetomidine was given to group D5, and 10 microg/kg dexmedetomidine was given to group D10. No medication was administered to the haemorrhage group (Group H). Malondialdehyde (MDA) and paraoxonase (PON) levels were measured at 48 hours after SAH. Mean wall thickness (MWT), mean luminal diameter (MLD), and proliferating cell nuclear antigen (PCNA) expression of the basilar artery were evaluated. MDA levels and MWT were lower in the dexmedetomidine groups. The lowest MDA levels and MWT were found in Group D10. The MLD was lowest in Group H. PCNA expression was observed only in Group D10. We concluded that dexmedetomidine reduces oxidative stress and vasospasm following SAH in a dose-dependent manner.

The Analgesic Effect of Dexketoprofen When Added to Lidocaine for Intravenous Regional Anaesthesia: A Prospective, Randomized, Placebo-Controlled Study

This prospective, randomized, placebo-controlled study evaluated the effects of dexketoprofen as an adjunct to lidocaine in intravenous regional anaesthesia (IVRA) or as a supplemental intravenous (i.v.) analgesic. Patients scheduled for elective hand or forearm soft-tissue surgery were randomly divided into three groups. All 45 patients received 0.5% lidocaine as IVRA. Dexketoprofen was given either i.v. or added into the IVRA solution and the control group received an equal volume of saline both i.v. and as part of the IVRA. The times of sensory and motor block onset, recovery time and postoperative analgesic consumption were recorded. Compared with controls, the addition of dexketoprofen to the IVRA solution resulted in more rapid onset of sensory and motor block, longer recovery time, decreased intra- and postoperative pain scores and decreased paracetamol use. It is concluded that coadministration of dexketoprofen with lidocaine in IVRA improves anaesthetic block and decreases postoperative analgesic requirements.

Anesthesia induction with sevoflurane and propofol: evaluation of P-wave dispersion, QT and corrected QT intervals.

The present study compared the effects of anesthesia induction with sevoflurane and propofol on hemodynamics, P‐wave dispersion (Pwd), QT interval and corrected QT (QTc) interval. A total of 72 adult patients were included in this prospective study. All patients had control electrocardiograms (ECGs) before anesthesia induction. Anesthesia was induced with sevoflurane inhalation or intravenous propofol. Electrocardiography for all patients was performed during the 1st and 3rd minutes of induction, 3 minutes after administration of muscle relaxant, and at 5 minutes and 10 minutes after intubation. Pwd and QT intervals were measured on all ECGs. QTc intervals were determined using the Bazett formula. There was no significant difference in Pwd and QT and QTc intervals on control ECGs. In the sevoflurane group, except for control ECGs, Pwd and QTc interval on all ECGs were significantly longer than those in the propofol group (p < 0.05). We conclude that propofol should be used for anesthesia induction in patients with a predisposition to preoperative arrhythmias, and in those whose Pwd and QTc durations are prolonged on preoperative ECGs.

Dexmedetomidine did not reduce the effects of tourniquet-induced ischemia-reperfusion injury during general anesthesia

Ischemia reperfusion injury causes the release of free oxygen radicals. Free oxygen radicals initiate the production of toxic metabolites, such as malondialdehyde (MDA), through the lipid peroxidation of cellular membranes. Following lipid peroxidation, the antioxidant enzyme system is activated against reactive oxygen species (ROS) and attempts to protect cells from oxidative damage. There is a balance between the scavenging capacity of antioxidant enzymes and ROS. Because of this balance, the total antioxidant capacity (TAC) measurement is a sensitive indicator of the overall protective effects of the antioxidants. Alpha2 receptor agonists are effective in preventing hemodynamic reactions during extremity surgeries by preventing the release of catecholamines secondary to tourniquet application. They have also been shown to possess preventive effects in various ischemia‐reperfusion injury models. In our study, we examined the effects of dexmedetomidine on tourniquet‐induced ischemia‐reperfusion injury in lower extremity surgeries performed under general anesthesia. The effects of dexmedetomidine were measured with serum MDA and TAC levels. We studied 60 adult American Society of Anesthesiologists (ASA) physical status I or II patients undergoing one‐sided lower extremity surgery with tourniquet. The patients were randomly divided into two groups. Group D was administered a dexmedetomidine infusion at a rate of 0.1 μg/kg/minute−1 for 10 minutes prior to induction and then at 0.7 μg/kg/hour−1 until 10 minutes before the end of the operation. The control group (Group C) received a saline infusion of the same amount and for the same period of time. General anesthesia was induced with thiopental, fentanyl, and rocuronium and maintained with nitrous oxide and sevoflurane in both groups. Venous blood samples were obtained before the administration of the study drugs (basal) at 1 minute before tourniquet release and at 5 and 20 minutes after tourniquet release (ATR). In both groups, MDA levels decreased at 5 and 20 minutes ATR when compared with the basal values (p < 0.05). TAC levels decreased at 1 and 5 minutes ATR and then returned to basal values at 20 minutes ATR (p < 0.05). In reference to the prevention of lipid peroxidation in tourniquet‐induced ischemia‐reperfusion injury, the results from the two groups in our study showed that dexmedetomidine did not have an additional protective role during routine general anesthesia.

Comparison of the effects of bupivacaine, lidocaine, and tramadol infiltration on wound healing in rats

BACKGROUND AND OBJECTIVES The aim of this study was to investigate the effects of saline solution, bupivacaine, lidocaine and tramadol infiltration on wound healing in rats. METHOD Thirty-two male Wistar Albino rats were randomly separated into four groups, receiving 3 mL saline solution in control group (Group C, n=8), 3 mL of 2% lidocaine in lidocaine group (Group L, n=8), 3 mL of 0.5% bupivacaine in bupivacaine group (Group B, n=8), and 3 mL of 5% tramadol in tramadol group (Group T, n=8). Breaking-strength measurements, collagen bundle counting, and histopathologic evaluation were evaluated in the tissue samples taken from the rats. RESULTS Comparing the control group with the groups where bupivacaine and lidocaine were used for wound infiltration, collagen production was lower, breaking-strength measurements showed reduced resistance while significantly high edema, vascularity, inflammation scores were found (p<0.0125). Between the control and the tramadol group there were no significant differences in collagen production, breaking-strength measurements, and edema, vascularity, inflammation scores (p>0.0125). CONCLUSION In our study, we found bupivacaine and lidocaine reduced the collagen production, wound breaking strength, and caused significantly high scores for edema, vascularity, and inflammation when compared to the control group. There was no significant difference between the control and the tramadol group. Results of this experimental preliminary study on rats support the idea that tramadol can be used for wound infiltration anesthesia without adverse effect on the surgical healing process. These results need to be verified in humans.

Does preincisional injection of levobupivacaine with epinephrine have any benefits for children undergoing tonsillectomy? An intraindividual evaluation

OBJECTIVE To evaluate the effects of peritonsillar injection of levobupivacaine with epinephrine in children undergoing adenotonsillectomy, through an intraindividual study. PATIENTS AND METHODS 20 children (age 6-13 years) undergoing elective tonsillectomy with or without adenoidectomy were enrolled in this prospective, randomized, intraindividual trial. After entubation and just prior to incision, 3 ml of 0.25% levobupivacaine with epinephrine was injected into one peritonsillar region while 0.9% saline was being used for the contralateral side. Amount of intraoperative blood loss, duration of tonsillectomy, postoperative pain, otalgia and hemorrhage were assessed for each side separately. Visual analog scale was used for postoperative pain assessment. Heart rate and mean arterial pressure during and after operation were also observed. The follow-up period after surgery was 10 days. RESULTS Median visual analog scale values for the levobupivacaine with epinephrine injected side was significantly lower than the saline injected side, during the first postoperative 16h (p<0.05). There were also significant differences between the intraoperative blood losses of the two sides (p<0.05). However; no significant differences were observed with respect to duration of surgery, postoperative otalgia and hemorrhage (p>0.05). CONCLUSION Preincisional injection of levobupivacaine with epinephrine decreases early postoperative pain and intraoperative blood loss as well.

Non-invasive mechanical ventilation with spinal anesthesia for cesarean delivery.

We present the successful use of perioperative non-invasive mechanical ventilation in a morbidly obese pregnant woman with bronchial asthma, severe preeclampsia and pulmonary edema undergoing an emergency cesarean delivery with spinal anesthesia. The combination of non-invasive mechanical ventilation with neuraxial anesthesia may be of value in selected parturients with acute or chronic respiratory insufficiency requiring surgery.