Treatment of severe sepsis and septic shock often focuses on resolving immediate life-threatening problems related to infection (source control, antibiotics) and providing circulatory, ventilatory and other organ support. Neurologic complications, such as sepsis-associated encephalopathy, frequently occur in septic patients and are associated with higher mortality and long-term complications. As case fatalities and overall mortality continue to decline, long-term cognitive problems are becoming more common among survivors. Although the aetiology of septic encephalopathy has not been clearly established, systemic inflammation appears to play a key role in altering both the blood–brain barrier permeability and amplifying the inflammatory response. Several new therapies are now aimed at reducing systemic inflammation. These may eventually play a role in reducing neurologic complications related to the acute pathophysiology of sepsis and may be able to reduce early cerebral dysfunction with the goal of reducing long-term neurologic complications. Coupled plasma filtration adsorption is an extracorporeal therapy aimed at the non-specific removal of cytokines and mediators involved in systemic inflammation and immune suppression by the use of plasma filtration coupled to an adsorbent resin cartridge with high affinity for many cytokines and mediators. Several cytokines that are removed by coupled plasma filtration adsorption have also been implicated in blood–brain barrier permeability, leucocyte recruitment and amplification of the inflammatory response. Current studies are ongoing to determine whether treatments such as coupled plasma filtration adsorption may also be beneficial in reducing long-term neurologic complications.

Summary

Recent articles published in peer review journals have questioned the safety of using aprotinin in patients having heart surgery. Also, evidence has been published to suggest an increase in renal events in patients given aprotinin when compared to those where tranexamic acid was used. The present review will focus principally on the first of these articles in relation to previously published data and experience.

Background and objective Situations may occur in anaesthetic practice where the use of neuromuscular blocking drugs is unsuitable or contraindicated. We investigated the use of propofol given 5 min after fentanyl to permit endotracheal intubation in children. Methods We studied the intubating conditions and cardiovascular parameters in 60 ASA I and II children. Intravenous midazolam (0.1mgkg−1) was given as premedication 5 min before the induction of anaesthesia. The children received different doses of propofol (group I, 2.5mgkg−1; group II, 3.0mgkg−1; group III, 3.5mgkg−1) preceded by fentanyl (3.0 μgkg−1) given 5 min earlier. No neuromuscular blocking agents were administered. The intubating conditionswere assessed using a four-point scoring system based on the degree of difficulty of laryngoscopy, the position of vocal cords and the intensity of coughing.

Results Tracheal intubating conditions were adequate in 20% of the patients in group I, in 75% of the patients in group II and in 80% of the patients in group III (P < 0.05 for group I vs. groups II and III). Haemodynamic changes were not significantly different between the groups.

Conclusions Propofol (3.0mgkg−1) preceded by fentanyl (3.0 μgkg−1) was adequate for the induction of anaesthesia in children and provided adequate tracheal intubating conditions without significant haemodynamic changes. This method represents a useful alternative technique for tracheal intubation when neuromuscular blocking drugs are contraindicated or should be avoided.

Summary

In this review paper, the authors critically analyse the use of a number of depth of anaesthesia monitors in light of the most recent literature and their own clinical experience. There appears to be increasing evidence that anaesthesia depth monitors reduce the incidence of unexpected intraoperative awareness and also that they improve the quality of anaesthesia. Proper use of these monitors necessitates background knowledge about the physiology of the loss of consciousness, the type of variable recorded and processed by the monitoring devices, the factors that might interfere with recording and the limits of use. The information provided by anaesthesia depth monitors is detailed and relationships with clinical practice are established to provide the reader with key features for optimal use of those monitors and correct interpretation of data. Practitioners and patient's knowledge and expectations regarding this matter, as well as the cost–benefit relationship are also discussed.

Ten patients, predicted to pose a difficult intubation of the trachea, underwent inhalational induction of anaesthesia using sevoflurane. In all 10 cases the airway was secured successfully and the patient proceeded to have the planned operation. In six of the cases the anaesthetist experienced a problem during the induction but in no case did this present any real difficulties or lead to a critical incident. We feel that sevoflurane has a place for inhalational induction in this challenging group of patients.

Summary

Background and objective: The aim of study was to investigate the electron microscopic changes in the medulla of the spinal cord that occur with intrathecal midazolam administration. Methods: Twenty-eight albino rabbits of New Zealand type were randomized into two groups. Following anaesthesia, 16 rabbits were given 300 μg of midazolam (Group M) and 12 rabbits were given 0.3 mL of normal saline solution (Group C) intrathecally. Eight rabbits from Group M (Group M1) and 6 rabbits from Group C (Group C1) were sacrificed 24 h after the anaesthesia and 8 rabbits from Group M (Group M2) and 6 rabbits from Group C (Group C2) were sacrificed 6 days after the anaesthesia. The lumbosacral portion was removed by laminectomy and thin sections were examined microscopically. Results: Severe separation in myelin lamella of the large axons, honeycomb appearance, slight separation in myelin lamella of small to moderately large axons, degenerate vacuoles in the cytoplasm and nuclear membrane irregularity were observed in neurons of Groups M1 and M2. Myelin lamella and nuclear membranes were found to be regular, vacuoles and oedema were observed in the neurons in the Groups C1 and C2. Conclusion: Midazolam administered at single dose by the intrathecal route may have neurotoxic effects on the neurons and myelinated axons at 24 h and 6 days following administration.

The direct cardiac effects of morphine, alfentanil, ketamine, etomidate, thiopentone, midazolam and propofol were measured in isolated Wistar rat hearts. Experiments were performed using a multiple conlumnar Langendorff apparatus and the hearts were perfused with a modified Tyrode solution under constant pressure. Each drug was applied from a different column in rising concentrations at 5-min intervals. Dose ranges were chosen to compare effects at sub-clinical, clinically relevant and more than clinical concentrations. Six rat hearts were chosen at random for each drug. Only thiopentone reduced contractile force at a clinically relevant concentration: measured as g contractility per g heart weight−1 (mean±standard deviation), base-line contractility was 8.8±2.4, and contractility at 10−4 mol litre−1 thiopentone was 7.1±1.5 (P<0.01). Alfentanil was the only drug to have no significant effect on the isolated heart at any concentration. Propofol was not cardiodepressant at clinically relevant concentrations, but had a lower therapeutic range than the other drugs.

Background and objective: To evaluate the ease with which successful insertion of a laryngeal mask airway can be performed in comparison with endotracheal intubation by medical personnel wearing chemical protective equipment.

Methods: Anaesthetists and non-anaesthetists (each n = 20) participated in the prospective comparative trial in an animal laboratory. The time and success rates of laryngeal mask airway vs. endotracheal tube insertions were measured as performed on anaesthetized monkeys.

Results: The results showed that the laryngeal mask airway was inserted more rapidly than the endotracheal tube by both groups (3.6 s and 28.6 s, P < 0.0001). Failed intubation occurred in 35% (anaesthetists) vs. 55% (non-anaesthetists) (P = 0.17).

Conclusions: In view of the 100% success rate of insertion even in unfavourable conditions, the possible role of the laryngeal mask airway in the scenario of a toxic mass casualty event should be considered.

Summary

Background and objective: Data on the effectiveness of cyclooxygenase 2 inhibitors in postoperative pain therapy vary widely. We tested in a prospective, placebo-controlled, randomized, double-blind trial the hypotheses that perioperative (i.e. preoperative and postoperative) administration of the cyclooxygenase 2 inhibitor rofecoxib decreases pain scores and morphine consumption after spine, breast and orthopaedic surgery. Methods: Five hundred and forty patients scheduled for spine, breast or orthopaedic surgery were randomly assigned to receive in combination with postoperative morphine via patient controlled analgesia pump for 4 days either rofecoxib 50 mg administered perioperatively, rofecoxib 50 mg administered only postoperatively, or placebo. Primary outcome criteria were pain score at rest (numeric rating scale 0–4) and morphine consumption. Results: Perioperative rofecoxib significantly decreased pain score 0 (0–1) vs. 1 (0–2) (median (interquartile range)), and morphine consumption 18 (6–33) vs. 22.5 (12–38) compared with placebo. In contrast, rofecoxib when administered only postoperatively did not significantly improve analgesic effects or side-effects at time of assessment of the main criteria (24 h after skin closure), but during the follow-up period at 48 h and 72 h after skin closure pain scores and morphine consumption were improved compared to placebo. The analgesic effects of rofecoxib were independent from the type of surgery. Conclusions: Perioperative administration of the cyclooxygenase 2 inhibitor rofecoxib decreases pain scores and morphine consumption after orthopaedic, breast and spine surgery. However, the benefit of preoperative administration of the cyclooxygenase 2 inhibitor seems to be only moderate, suggesting that early postoperative administration may be a useful alternative approach. There is no evidence that the type of surgery influences analgesic effects of cyclooxygenase 2 inhibitors.

Summary

Background and objective: It is widely accepted that sevoflurane affects cerebral circulation, but there are uncertainities regarding the magnitude of its effect. The aim of the present work was to assess the effect of sevoflurane on the cerebral circulation at surgical levels of anaesthesia. Methods: Twenty patients undergoing elective lumbar discectomies were investigated. Anaesthesia was induced with propofol and maintained with sevoflurane. The level of surgical anaesthesia was determined by bispectral index, the target level was 45–55. Transcranial Doppler (TCD) measurement was performed before induction and after reaching the surgical level of anaesthesia. Besides routine parameters (middle cerebral artery mean blood flow velocity (MCAV) and pulsatility index (PI)) derived parameters (estimated cerebral perfusion pressure (eCPP), cerebral blood flow index (CBFI) and resistance area product (RAP)) were calculated by taking changes of mean arterial pressure also into account. Results: MCAV decreased from 54.1 ± 13.3 to 43.7 ± 18.5 cm s−1, P < 0.01 and PI increased from 0.79 ± 0.2 to 0.92 ± 0.2, P < 0.01 after reaching the surgical level of anaesthesia. As a result eCPP decreased by 18.2%, CBFI by 25.5% and RAP increased by 15% respectively. Conclusions: Our data indicate a vasodilatory effect of sevoflurane at surgical level of anaesthesia on large cerebral vessels or a vasoconstriction of the resistance arterioles likely caused by decreased brain metabolism.

Sedation is frequently used during ophthalmic regional anaesthesia. There is no ‘ideal’ drug for sedation or analgesia. Various drugs either alone or in combination have been used with different methods of administration. This review includes the roles of sedation, the pharmacology of drugs and the safety of sedation in patients undergoing ophthalmic surgery.

Summary

Background and objective: Propofol may cause undesirable hypotension due to vasodilation. The underlying mechanisms are not completely understood. We investigated the mechanisms by which propofol relaxes vascular segments.

Methods: We studied the effect of propofol on isolated porcine coronary artery rings precontracted with potassium chloride or prostaglandin F2α.

Results: Propofol, in a concentration-dependent manner, relaxed all segments at concentrations of 5 μg mL−1 and above. This relaxation was unaltered in the presence of Nω-nitro-L-arginine, indomethacin, diltiazem and glibenclamide. Tetraethylammonium chloride, an inhibitor of the BKCa K+ channel (a high conductance Ca2+-sensitive K+ channel), dose-dependently attenuated the vasodilating effect of propofol (P < 0.001).

Conclusions: Our results suggests that the activation of the BKCa channel may contribute to the vasodilating effect of propofol, hereby causing hyperpolarization of the smooth muscle membrane and reduction of smooth muscle tone.

Summary

Background and objectives: This was a prospective audit to assess the incidence and characteristics of early postoperative complications in the recovery room in extubated patients after elective neurosurgical procedures using propofol and remifentanil-based total intravenous anaesthesia. Methods: Vital signs (temperature, conscious level, respiratory rate, oxygen saturation, pulse and blood pressure) and postoperative complications (shivering, nausea, vomiting and cardiorespiratory) were analysed in 145 adult patients over a 1-yr period. Results: The overall shivering, postoperative nausea and vomiting and postoperative hypertension (systolic blood pressure more than 25% of the preoperative value) incidences were 30.3%, 16.6% and 35.2%, respectively. Fifty-one percent of the patients had at least one of the above complications. The complication rates were found to be widely different among various types of neurosurgery. The surgical procedures were divided into five groups: supratentorial craniotomy, posterior fossa craniotomy, intracranial vascular procedures, transphenoidal hypophysectomy and extracranial procedures. Median extubation time was similar in all groups and patients were fully conscious with no hypoxia in the recovery room. The intracranial vascular group had the highest shivering and postoperative nausea and vomiting rates (58.8% and 29.4%, respectively). In the supratentorial craniotomy group, 46% of the patients had hypertension. The overall complication rate (presence of any complications) was highest in the supratentfial craniotomy (55.4%), posterior fossa craniotomy (75%) and intracranial vascular (76.5%) groups. Shivering and overall complication rate was significantly related to the anaesthetic time (P ≤ 0.001 and 0.02, respectively). Conclusions: Despite the potential advantages of total intravenous anaesthesia in titratability, rapid return of consciousness and reduced respiratory complications, making it suitable for planned extubation at the end of neurosurgery, the postoperative complications of shivering, postoperative nausea and vomiting and hypertension were still high.

Background and objective We have assessed the analgesic efficacy and side-effects of neostigmine when added to lidocaine for axillary brachial plexus block, in a prospective, randomized, double-blind, placebo-controlled study.

Methods We studied 34 ASA I or II patients undergoing elective ambulatory carpal tunnel release. Axillary brachial plexus block was performed using a peripheral nerve stimulator to locate the median nerve. All patients were administered 1.5% lidocaine 450 mg and epinephrine 5 μg mL−1. Patients were allocated randomly to one of two groups. Neostigmine 500|ig was added in group N, and saline 1 mL in group S.

Results The duration of analgesia did not significantly differ between groups [mean (SD)]: 812.5 (456.9) for group S vs. 746.7 (474.1) min for group N (P >0.05). The need for supplementary analgesia did not significantly differ between groups: 4.4 (1.5) extra doses for group S vs. 3.8 (2.2) extra doses for group N (P>0.05). Visual analogue pain scores and occurrence of side-effects did not significantly differ between groups.

Conclusion Neostigmine does not seem to be of clinical value for peripheral nerve blocks.