Tracheal extubation is a high‐risk phase of anaesthesia. The majority of problems that occur during extubation and emergence are of a minor nature, but a small and significant number may result in injury or death. The need for a strategy incorporating extubation is mentioned in several international airway management guidelines, but the subject is not discussed in detail, and the emphasis has been on extubation of the patient with a difficult airway. The Difficult Airway Society has developed guidelines for the safe management of tracheal extubation in adult peri‐operative practice. The guidelines discuss the problems arising during extubation and recovery and promote a strategic, stepwise approach to extubation. They emphasise the importance of planning and preparation, and include practical techniques for use in clinical practice and recommendations for post‐extubation care.

Difficult Airway Society Guidelines for the management of tracheal extubation: Management of tracheal extubation

Oxidative Stress in Schizophrenia: An Integrated Approach

The blood–brain barrier (BBB) forms a protective barrier around the brain, with the important function of maintaining brain homeostasis. Pathways thought to initiate BBB dysfunction include the kin...

Involvement of ROS in BBB dysfunction

Purpose of review The present review serves as an overview update in the diverse uses of the sedative dexmedetomidine. Recent findings Dexmedetomidine is a selective alpha2 adrenoreceptor agonist that has been described as a useful, safe adjunct in many clinical applications. This paper reviews current clinical uses, mechanism of action, and side effects of dexmedetomidine. The current uses reviewed include sedation in the ICU (adult and pediatric), neurosurgery, pediatric procedural sedation, awake fiber-optic intubation, cardiac surgery, and bariatric surgery. Summary Dexmedetomidine is a useful medication with many clinical applications. The medication has shown efficacy in decreasing the need for opioids, benzodiazepines, propofol, and other sedative medications. Short-term sedation has been shown to be safe in studies, although hypotension and bradycardia are the most significant side effects. Dexmedetomidine has been used effectively for sedation during pediatric procedures and in the ICU. In order to reduce sympathetic tone during cardiac surgery, a low-dose dexmedetomidine infusion has been utilized. The bariatric surgery population has also been studied with dexmedetomidine because of its adequate sedation and less prevalent respiratory depression when compared with opioid administration. Dexmedetomidine is emerging as an effective therapeutic agent in the management of a wide range of clinical conditions with an efficacious, safe profile.

Dexmedetomidine: A Review of Clinical Applications

Ketamine thereforerepresents a promising modality in several perioperativestrategies to prevent pathologic pain.Another reason for the renewed interest in ketamine isthe availability of S( ) ketamine. Ketamine has a chiralcenter at the carbon-2 atom of the cyclohexanone ring,and therefore exists as the optical stereoisomers S( )and R(-) ketamine.

Ketamine for Perioperative Pain Management

Background We evaluated the sedative, haemodynamic and respiratory effects of dexmedetomidine and compared them with those of midazolam in children undergoing magnetic resonance imaging (MRI) procedures. Methods Eighty children aged between 1 and 7 yr were randomly allocated to receive sedation with either dexmedetomidine (group D, n=40) or midazolam (group M, n=40). The loading dose of the study drugs was administered for 10 min (dexmedetomidine 1 μg kg−1 or midazolam 0.2 mg kg−1) followed by continuous infusion (dexmedetomidine 0.5 μg kg−1 h−1 or midazolam 6 μg kg−1 min−1). Inadequate sedation was defined as difficulty in completing the procedure because of the child's movement during MRI. The children who were inadequately sedated were given a single dose of rescue midazolam and/or propofol intravenously. Mean arterial pressure (MAP), heart rate (HR), peripheral oxygen saturation (
				 S p O 2 ) and ventilatory frequency (VF) were monitored and recorded during the study. Results The quality of MRI was significantly better and the rate of adequate sedation was higher in group D than in group M (P Conclusions Dexmedetomidine provided adequate sedation in most of the children aged 1–7 yr without haemodynamic or respiratory effects during MRI procedures.

Sedative, haemodynamic and respiratory effects of dexmedetomidine in children undergoing magnetic resonance imaging examination: preliminary results

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.

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

Summary
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.

Methods: After approval of the Ethics Committee and informed parental consent, 40 patients, ASA I–II, aged 3–12 years, who were scheduled for tonsillectomy or/and adenoidectomy, were randomly divided into two groups. Anaesthesia was induced with sevoflurane, lidocaine 1 mg·kg−1, alfentanil 10 µg·kg−1, vecuronium 0.1 mg·kg−1 and maintained with sevoflurane 2% and 60% nitrous oxide in oxygen. After intubation, patients in group I received 15 mg·kg−1 magnesium in 30 ml 0.9% NaCl over 20 min. Patients in group II received 0.9% NaCl alone in the same volume. After reversal of neuromuscular blockade, all patients were extubated at a very deep plane of anaesthesia. The incidence of laryngospasm was determined until the time of discharge from the postanaesthesia care unit.

Results: Although laryngospasm was not observed in group I, it was observed in five patients in group II (25%). The incidence of laryngospasm in group II was significantly higher than group I. The plasma magnesium concentrations were significantly higher in group I than group II.

Conclusions: We found a significant decrease in the incidence of laryngospasm in paediatric patients receiving magnesium. It is suggested that the use of intravenous magnesium intraoperatively may prevent laryngospasm.

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

SummaryBackground 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.

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

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)-alpha, 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-alpha, 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.

Semra Demirbilek

Papers

Sedative, haemodynamic and respiratory effects of dexmedetomidine in children undergoing magnetic resonance imaging examination: preliminary results

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

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

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

Small-dose capsaicin reduces systemic inflammatory responses in septic rats.