Semra Demirbilek

Antioxidant properties of propofol and erythropoietin after closed head injury in rats.

Reactive oxygen species play a role during brain injury due to closed head trauma. Enzymatic or nonenzymatic antioxidants may protect brain tissue against oxidative damage. The present study was performed to assess the changes of endogenous indices of oxidative stress in serum from rats subjected to head trauma and whether treatment with propofol and/or erythropoietin (EPO) modifies the levels of endogenous indices of oxidative stress. For these purposes, female Wistar Albino rats were divided into five groups: non-traumatic sham group, trauma performed control, trauma with propofol (i.p.), trauma with EPO (i.p.) and trauma with propofol and EPO performed study groups. At the end of the experimental procedure, blood was taken by cardiac puncture to determine superoxide dismutase (SOD) and xanthine oxidase (XO) activities as well as malondialdehyde (MDA) and nitric oxide (NO) levels in serum. Serum MDA level of control traumatic brain injury (TBI) group was significantly higher than sham operation group (p<0.012). Serum MDA levels in propofol, EPO and propofol+EPO groups were found to be decreased in comparison with control group (p<0.039, p<0.030 and p<0.018, respectively). Serum NO level was found to be increased in TBI group, but difference was not statistically significant when compared to sham-operated group (p=0.092). Propofol, EPO and propofol+EPO administration efficiently reduced serum NO levels to reach sham-operated group (p<0.002, p<0.001 and p<0.015, respectively). These results suggested that acute administration of both propofol and EPO altered the indices of oxidative stress similarly against brain injury due to trauma.

Small-Dose Capsaicin Reduces Systemic Inflammatory Responses in Septic Rats

We investigated the influence of small- and large-dose capsaicin in modulating systemic inflammatory responses during different stages of sepsis in rats. Rats were divided into six groups: group C, control; group S, sepsis; group CLC, small dose of capsaicin (1 mg/kg subcutaneously); group SLC, small dose of capsaicin plus sepsis; group CHC, large dose of capsaicin (150 mg/kg subcutaneously); group SHC, large dose of capsaicin plus sepsis. Rats were made septic by cecal ligation and puncture (CLP). Each group was subdivided into two subgroups. The animals were killed at 9 or 18 h after CLP. Plasma concentrations of calcitonin gene-related peptide (CGRP), tumor necrosis factor (TNF)-&agr;, interleukin (IL)-6, IL-10, and total nitrite/nitrate (NOx) were measured. Superoxide dismutase and malondialdehyde (MDA) were determined in liver, lung, and heart tissues. CGRP was increased in groups S, CLC, and SLC when compared with the other groups. In the SLC group, plasma concentrations of TNF-&agr;, IL-6, NOx, and tissue MDA levels were reduced and IL-10 level was increased when compared with groups S and SHC 18 h after CLP (P < 0.05). Small-dose capsaicin treatment increased antiinflammatory IL-10 levels and attenuated the increases in proinflammatory cytokines, NOx, and tissue MDA in septic rats.

The use of magnesium to prevent laryngospasm after tonsillectomy and adenoidectomy: a preliminary study.

Background: Laryngospasm is the most common cause of upper airway obstruction after tracheal extubation. Magnesium has a central nervous system depressant property, which contributes to the depth of anaesthesia. It also has calcium antagonist properties, which provide muscle relaxation. In this study, we aimed to determine the effect of magnesium on preventing laryngospasm.

Effects of fentanyl on the incidence of emergence agitation in children receiving desflurane or sevoflurane anaesthesia.

Background and objective: In children, emergence agitation frequently complicates sevoflurane and desflurane anaesthesia. The effect of intravenous fentanyl 2.5 μg kg−1 was examined on the incidence of emergence agitation in children who received desflurane or sevoflurane after midazolam premedication and intravenous thiopental induction. Methods: One hundred and twenty children (2-7 yr) undergoing adenoidectomy or tonsillectomy, or both, were studied. All children were premedicated orally with midazolam 0.5 mg kg−1. After intravenous induction with thiopental and atracurium to facilitate endotracheal intubation, patients were randomly assigned to one of four groups: Patients in Groups 1 and 3 received physiological saline solution, whereas patients in Groups 2 and 4 received intravenous fentanyl 2.5 μg kg−1 during induction. Anaesthesia was maintained with sevoflurane in Groups 1 and 2 and with desflurane in Groups 3 and 4. After discontinuation of the volatile anaesthetic, the times to tracheal extubation and response to verbal stimuli (emergence time), and emergence behaviours were recorded. Results: The time to tracheal extubation was significantly shorter in Groups 3 (5.2 ± 1.7 min) and 4 (6.4 ± 2.1 min) than in Groups 1 (8.1 ± 2.1 min) (P = 0.0001 and 0.006, respectively) and 2 (8.8 ± 1.9 min) (P = 0.0001). The emergence time was significantly shorter in Group 3 (10.0 ± 3.9 min) than in Groups 1 (13.8 ± 4.9 min) (P = 0.017) and 2 (14.9 ± 4.1 min) (P = 0.003). The incidence rate of severe agitation was 13% in Groups 1 and 3, and 7 and 10% in Groups 2 and 4, respectively (P > 0.05). Conclusions: After midazolam premedication and intravenous induction of anaesthesia with thiopental, administration of intravenous fentanyl 2.5 μg kg−1 did not provide any clinically significant benefit on emergence agitation in children who receive sevoflurane or desflurane anaesthesia.

Propofol and erythropoietin antioxidant properties in rat brain injured tissue

So far, several treatment modalities have been attempted to brain protection in cases such as brain trauma, stroke or brain hemorrhage. However, a treatment method that the effect begins immediately and definitely helpful has not been discovered yet. In this study, we aimed to compare the effects of propofol and erythropoietin (Epo) on brain injury caused by oxidative stress and antioxidant properties of these agents after closed head injury (CHI) in rats. For this study, female Wistar Albino rats were divided into five groups: non-traumatic control group, trauma performed group CHI, trauma with propofol (100 mg/kg) intraperitoneally (i.p.), trauma with Epo (5000 U/kg) i.p. and trauma with propofol and Epo performed study groups. Twenty-four hours after CHI, rats were sacrificed and the brains were removed. Superoxide dismutase (SOD), catalase (CAT), xanthine oxidase (XO), nitric oxide (NO), and malondialdehyde (MDA) levels were measured in brain tissue. MDA and NO levels were decreased significantly in Groups Epo, Propofol and Epo+Propofol than Group CHI (p<0.01). XO activity was significantly lower in Group Epo than Group CHI (p<0.05). Epo and propofol decreased oxidative stress by decreasing MDA and NO level in brain tissue after CHI. However, combination of Epo and propofol has no significant beneficial advantage than Epo or propofol alone.

Effects of S (+) ketamine added to bupivacaine for spinal anaesthesia for prostate surgery in elderly patients

Background and objective: Intrathecal ketamine as the sole anaesthetic agent has demonstrated a lack of cardiovascular depression that should be of advantage in an elderly population. S(+) ketamine has three-times the analgesic potency of R(−) ketamine and its antinociceptive effects after intrathecal administration in rats are known. We decided to evaluate the effects of intrathecal S(+) ketamine added to a small dose of spinal bupivacaine in elderly patients undergoing transurethral prostate surgery. Methods: Forty males over 60 yr old, scheduled for transurethral prostate resection under spinal anaesthesia, were studied in a prospective, double-blinded, randomized way. Patients were allocated to receive either bupivacaine 10 mg or bupivacaine 7.5 mg combined with S(+) ketamine 0.1 mg kg−1. Spinal block onset time, maximum sensory level, duration of blockade, haemodynamic variables, postoperative analgesic requirements and adverse events were recorded. Results: Onset times of motor and sensory block were shorter in the bupivacaine plus S(+) ketamine group. Incomplete motor block of the lower extremities was seen in 80% of the patients in bupivacaine plus S(+) ketamine group. Duration of complete motor block and spinal analgesia was shorter in the bupivacaine plus S(+) ketamine group. There was no significant difference in arterial pressure. Heart rate decreased after spinal anaesthesia in the bupivacaine plus S(+) ketamine group and was significantly lower until the end of anaesthesia. The incidence of adverse effects was not different between groups. Conclusions: Intrathecal S(+) ketamine administered with a low dose of bupivacaine provides shorter motor and sensory block onset time, shorter duration of action and less motor blockade in elderly males.

The effects of intrathecal levobupivacaine and bupivacaine in the elderly

The objective of this study was to compare the block durations and haemodynamic effects associated with intrathecal levobupivacaine or bupivacaine in elderly patients undergoing transurethral prostate surgery. Eighty patients were prospectively randomised to receive plain 1.5 ml levobupivacaine 0.5% (group levobupivacaine) or 1.5 ml plain bupivacaine 0.5% (group bupivacaine) in combination with fentanyl 0.3 ml (15 μg) for spinal anaesthesia. The time to reach T10 and peak sensory block level, and to maximum motor block were significantly shorter in group bupivacaine compared to group levobupivacaine (p < 0.05). Peak sensory block level was also significantly higher in group bupivacaine. In group bupivacaine, mean arterial pressure was significantly lower than group levobupivacaine, starting from 10 min until 30 min after injection (p < 0.05). Hypotension and nausea were less common in group levobupivacaine than group bupivacaine (p < 0.05). Because of the better haemodynamic stability and fewer side‐effects associated with levobupivacaine, it may be preferred for spinal anaesthesia in elderly patients.

The effect of esmolol on the QTc interval during induction of anaesthesia in patients with coronary artery disease.

The aim of this study was to evaluate whether esmolol has an effect on QT interval during induction of anaesthesia using etomidate and fentanyl in patients with known coronary artery disease. Sixty patients were prospectively randomised to either a control group or the esmolol group. Esmolol was administered as a bolus 1 mg.kg−1, followed by a continuous infusion at 250 μg.kg−1min−1. All patients received etomidate 0.3 mg.kg−1 and fentanyl 15 μg.kg−1. The ECG was recorded prior to induction of anaesthesia (T0), 5 min following the start of drug infusions (T1), 1 min following etomidate (T2), 3 min following vecuronium (T3), 30 s (T4), 2 min (T5) and 4 min (T6) after intubation. In the esmolol group, QTc interval was significantly shorter at T1, T2 and T4 compared to the control group (p < 0.05). In conclusion, QTc interval increased following tracheal intubation during induction of anaesthesia using etomidate and fentanyl. An infusion of Esmolol attenuated the QTc interval prolongation associated with tracheal intubation.

Comparison of propofol–alfentanil and propofol–remifentanil anaesthesia in percutaneous nephrolithotripsy

Background and objective: Percutaneous nephrolithotripsy (PCNL) is used for the fragmentation and removal of stones from the renal pelvis and renal calyceal systems. We compared the effects of propofol‐alfentanil or propofol‐remifentanil anaesthesia on haemodynamics, recovery characteristics and postoperative analgesic requirements during percutaneous nephrolithotripsy. Methods: Thirty non‐premedicated patients were randomly allocated to receive either propofol‐alfentanil (Group A) or propofol‐remifentanil (Group R). The loading dose of the study drug was administered over 60 s (alfentanil 10 μg kg−1 or remifentanil 1 μg kg−1) followed by a continuous infusion (alfentanil 15 μg kg−1 h−1 or remifentanil 0.15 μg kg−1 min−1). Propofol was administered until loss of consciousness and maintained with a continuous infusion of 75 μg kg−1 min−1 in both groups. Atracurium was given for endotracheal intubation at a dose of 0.5 mg kg−1 and maintained with a continuous infusion of 0.4 mg kg−1 h−1. Mean arterial pressure heart rate, the total amount of propofol, time of recovery of spontaneous ventilation, extubation and eye opening in response to verbal stimulus and analgesic requirement were recorded. Results: In Group A, mean arterial pressure was higher at the first minute in the prone position, and during skin incision and lithotripsy, and heart rate was higher during skin incision and lithotripsy when compared with Group R (P < 0.05). The total amount of propofol did not differ between groups. Time of recovery of spontaneous ventilation, extubation and eye opening were significantly shorter in Group R than Group A (P < 0.05). Conclusions: Both propofol‐remifentanil and propofol‐alfentanil anaesthesia provided stable haemodynamics during percutaneous nephrolithotripsy, whereas propofol‐remifentanil allowed earlier extubation.

Ketamine or alfentanil administration prior to propofol anaesthesia: the effects on ProSeal™ laryngeal mask airway insertion conditions and haemodynamic changes in children

This study was designed to compare the effects of ketamine and alfentanil administered prior to induction of anaesthesia with propofol, on the haemodynamic changes and ProSeal laryngeal mask airway® (PLMA) insertion conditions in children. Eighty children, aged between 3–132 months, were randomly allocated to receive either alfentanil 20 μg.kg−1 (alfentanil group) or ketamine 0.5 mg.kg−1 (ketamine group) before induction of anaesthesia. Ninety seconds following the administration of propofol 4 mg.kg−1, a PLMA was inserted. In the ketamine group, heart rate and mean arterial pressure were higher during the study period compared with the alfentanil group (p < 0.05). The time for the return of spontaneous ventilation was prolonged in the alfentanil group (p = 0.004). In conclusion, we found that the administration of ketamine 0.5 mg.kg−1 with propofol 4 mg.kg−1 preserved haemodynamic stability, and reduced the time to the return of spontaneous ventilation, compared with alfentanil 20 μg.kg−1 during PLMA placement. In addition, the conditions for insertion of the PLMA with ketamine were similar to those found with alfentanil.