The aim of this study was to evaluate the efficacy of dexmedetomidine, an α2-adrenoceptor agonist, on intraoperative bleeding, anaesthetic drug requirement and postoperative pain.

Forty patients scheduled for elective tympanoplasty and septorhinoplasty operations under general anaesthesia were included in the study. The patients were randomly assigned to receive either a dexmedetomidine 1 μg kg−1 bolus 10 min before induction of anaesthesia plus 0.5 μg kg−1 h−1 infusions during maintenance or placebo. Mean arterial pressure was maintained between 60 and 80 mmHg. Perioperative mean arterial pressure, heart rate, time to extubation and time to awakening were recorded. Bleeding during surgery was assessed by the surgeon, blinded to the study drugs, both intraoperatively and postoperatively as a final personal opinion about the whole surgical process.

The heart rate and mean arterial pressure were significantly lower during induction, operation and extubation in the dexmedetomidine group (P < 0.05). Blood losses were lower in the dexmedetomidine group (P < 0.05). Propofol dose required for induction, and fentanyl and isoflurane consumption were significantly reduced in the dexmedetomidine group (P < 0.05). The total amounts of nitroglycerin and meperidine used were higher in the control group (P < 0.05).

Dexmedetomidine decreased bleeding, postoperative analgesic requirements and intraoperative anaesthetic requirements and was associated with more stable haemodynamic responses to anaesthesia. We conclude that dexmedetomidine is a useful adjuvant to decrease bleeding when a bloodless surgical field is requested.

The kind of fluid for correcting hypovolaemia is still a focus of debate. In a prospective, randomized, controlled and double-blind study in patients undergoing major abdominal surgery, a total balanced volume replacement strategy including a new balanced hydroxyethyl starch (HES) solution was compared with a conventional, non-balanced fluid regimen.

In Group A (n = 15), a new balanced 6% HES 130/0.42 was given along with a balanced crystalloid solution; in Group B (n = 15), an unbalanced conventional HES 130/0.42 plus an unbalanced crystalloid (saline solution) were administered. Volume was given when mean arterial pressure (MAP) was <65 mmHg and central venous pressure (CVP) minus positive end-expiratoric pressure (PEEP) level was <10 mmHg. Haemodynamics, acid–base status, coagulation (thrombelastography (TEG)) and kidney function (including kidney-specific proteins, N-acetyl-beta-d-glucosaminidase (beta-NAG) and alpha-1-microglobulin) were measured after induction of anaesthesia, at the end of surgery, 5 and 24 h after surgery.

Group A received 3533 ± 1302 mL of HES and 5333 ± 1063 mL of crystalloids, in Group B, 3866 ± 1674 mL of HES and 5966 ± 1202 mL of crystalloids were given. Haemodynamics, laboratory data, TEG data and kidney function were without significant differences between the groups. Cl− concentration and base excess (−5 ± 2.4 mmol L−1 vs. 0.4 ± 2.4 mmol L−1) were significantly higher in patients of Group B than of Group A.

A complete balanced volume replacement strategy including a new balanced HES preparation resulted in significantly less derangement in acid–base status compared with a non-balanced volume replacement regimen. The new HES preparation showed no negative effects on coagulation and kidney function.

This study follows up an initial audit in 1992 indicating that anaesthetic machine checking practices were often incomplete. The aims were to ascertain if there has been any improvement during this period with special reference to the latest guidelines.

Following the Association of Anaesthetists of Great Britain and Ireland machine checking guidelines, a structured questionnaire, was used to interview 41 anaesthetists in the South West region on one particular day.

Despite 80% of subjects stating that they had read the latest guidelines recently, only one undertook a complete check and 39/41 (95%) performed partial checks (omitting one or more steps in the guidelines). Steps most commonly omitted were additional monitoring, ventilator function, availability of an alternative means of ventilation and function of ancillary equipment such as laryngoscopes. Only 5/41 subjects performed any check between cases. Several of these checks have been introduced in the 2004 guidelines.

Although there has been a significant increase in the proportion of anaesthetists undertaking machine checks since 1992 (P = 0.0007), we conclude that machine checking guidelines are still poorly followed, with checks specific to the latest guidelines most likely to be omitted.

The laryngeal mask has become a widely accepted alternative to endotracheal intubation and mask ventilation. The laryngeal tube is a relatively new supraglottic airway device for airway management. We compared the new version of the laryngeal tube with the laryngeal mask.

In a randomized design, either a laryngeal tube (n = 66) or a laryngeal mask (n = 66) were inserted. Ease of insertion, oxygenation and ventilation, spirometry data and postoperative airway morbidity were determined.

After successful insertion, it was possible to maintain oxygenation and ventilation in all the patients. Insertion success rates after the first, second and third attempts were 84.8% (n = 56), 12.1% (n = 8) and 3% (n = 2) for the laryngeal tube compared with 56.1% (n = 37), 25.8% (n = 17) and 18.2% (n = 12) for the laryngeal mask (P = 0.001). There was no significant difference in peak airway pressure, and dynamic compliance between the groups (P > 0.05). Blood on the cuff after removal of the device was noted in one patient with the laryngeal tube and in 10 patients with the laryngeal mask. Six patients in the laryngeal mask group complained of hoarseness (P = 0.012).

With respect to clinical function, the new version of the laryngeal tube and the laryngeal mask are similar and either device can be used to establish a safe and effective airway in paralysed patients.

Acupuncture has been claimed to be associated with activation of the endogenous antinociceptive system. The analgesic effects of acupuncture have been ascribed to β-endorphin interacting with opioid receptors. However, firstly, the release of β-endorphin into the blood has been proven to be induced by stress, i.e. under dysphoric conditions, and, secondly, if released under stress, β-endorphin has been shown not to be analgesic. Our aim was to test whether β-endorphin immunoreactive material is released into the cardiovascular compartment during acupuncture comparing the most frequently used types of acupuncture with standard pain treatment under apparently low stress conditions.

This prospective study included 15 male patients suffering from chronic low back pain. β-Endorphin immunoreactive material and cortisol were measured in the plasma of patients who underwent, in randomorder, therapy according to a standard pain treatment, traditional Chinese acupuncture, sham acupuncture, electro acupuncture and electro acupuncture at non-acupuncture points before, at and after the treatment. Statistical analysis was performed using two-way ANOVA with repeated measures.

A decrease in plasma cortisol concentration measured over the five treatment protocols was highly significant (P < 0.001). The β-endorphin immunoreactive material concentrations in plasma were minimal at all times and in all treatment conditions. The influence of treatments by various acupuncture procedures on cortisol and β-endorphin immunoreactive material plasma concentrations over the three time points was not significantly different.

β-endorphin immunoreactive material in blood is not released by any type of acupuncture as tested under low stress conditions.

Ventilator-associated pneumonia is a nosocomial infection that occurs in patients receiving mechanical ventilation for >48 h. Many aspects of its diagnosis, treatment and management are controversial. We used a postal questionnaire to survey current practice within the UK.

Questionnaire study of 207 general intensive care units in the UK.

The response rate was 77.3%. Regarding diagnosis, 30% of units obtained specimens from the lungs invasively, while the remainder relied on tracheal aspirates. In only 28.2% of units using tracheal aspirates were results reported in a quantitative manner. A clinical suspicion of ventilator-associated pneumonia would lead to the administration of empirical antibiotic therapy in the majority of units (77.2%), opinion being almost equally divided on whether this should be mono (49.1%) or combination therapy (50.9%). Although most units received regular microbiology feedback (90.5%), the involvement of a microbiologist in the antibiotic decision-making process was variable. Antibiotics were continued for a median of 7 days (inter-quartile range 5–8.5, range 2–14 days). Compliance with the principal methods of ventilator-associated pneumonia prevention was good.

There is widespread variation in the methods used for the diagnosis of ventilator-associated pneumonia within the UK. The majority of units rely on non-quantitative analysis of tracheal aspirates. This technique has a high percentage of false-positives, and suggests widespread over utilization of antibiotics. However, most agree that antibiotics should be given empirically when there is a clinical suspicion of ventilator-associated pneumonia. The widespread introduction of ‘ventilator bundles’ appears to have ensured that most units actively take measures to prevent ventilator-associated pneumonia.

Atrial and brain natriuretic peptide, synthesized by cardiac myocytes, are mediators secreted secondary to cardiac volume expansion and increased filling pressure. The study was designed to assess serum concentration of atrial and brain natriuretic peptide in patients undergoing endonasal sinus surgery receiving controlled hypotension.

We studied 45 patients without cardiovascular history, scheduled for elective endonasal sinus surgery. Patients were allocated to one of three groups: controlled hypotension was induced either by using esmolol (n = 15) or sodium nitroprusside (n = 15) with a mean arterial pressure of 50–55 mmHg. In the control group (n = 15), mean arterial pressure was adjusted to 70–80 mmHg. Atrial and brain natriuretic peptides were measured preoperatively (T1), at the end of surgery (T2), 2 h (T3), 24 h (T4) and 48 h (T5) postoperatively.

Preoperative atrial and brain natriuretic peptide plasma levels were within normal ranges and similar between all groups. Patients treated with esmolol (atrial natriuretic peptide: 2.46 ± 0.75 μg mL−1; brain natriuretic peptide: 4.34 ± 3.06 μg mL−1) and sodium nitropusside (atrial natriuretic peptide: 2.48 ± 0.92 μg mL−1; brain natriuretic peptide: 4.49 ± 3.21 μg mL−1) showed significantly lower concentrations of atrial and brain natriuretic peptide at T2 and T3 compared with controls (atrial natriuretic peptide: 5.31 ± 2.32 μg mL−1; brain natriuretic peptide: 13.26 ± 8.98 μg mL−1, P < 0.01) as well as a reduction in blood loss and duration of surgery.

Controlled hypotension decreases the release of natriuretic peptides in cardiovascular healthy patients. This effect may be contributed to by changes in cardiac filling pressure due to lower systemic resistance and diminished perfusion pressure.

The aim of this study was to determine which of two clinically applied methods, electromyography or acceleromyography, was less affected by external disturbances, had a higher sensitivity and which would provide the better input signal for closed loop control of muscle relaxation.

In 14 adult patients, anaesthesia was induced with intravenous opioids and propofol. The response of the thumb to ulnar nerve stimulation was recorded on the same arm. Mivacurium was used for neuromuscular blockade. Under stable conditions of relaxation, the infusion-rate was decreased and the effects of turning the hand were investigated.

Electromyography and acceleromyography both reflected the change of the infusion rate (P = 0.015 and P < 0.001, respectively). Electromyography was significantly less affected by the hand-turn (P = 0.008) than acceleromyography. While zero counts were detected with acceleromyography, electromyography could still detect at least one count in 51.1%.

Electromyography is more reliable for use in daily practice as it is less influenced by external disturbances than acceleromyography.

The efficacy, tolerability and the morphine-sparing effects of lornoxicam were compared with those of tenoxicam when used preoperatively in patients undergoing laparoscopic cholecystectomy.

In this prospective, double-blind study, 60 ASA I–II patients undergoing laparoscopic cholecystectomy were randomized equally to receive intravenous tenoxicam 40 mg (Group T) or lornoxicam 16 mg (Group L), preemptively. Three patients withdrew from the study, so 57 patients were included in the analysis. In the postoperative period, the first morphine demand times, pain scores, side-effects and cumulative morphine consumptions were evaluated during the first 24 h.

The patient characteristics data and the duration of surgery were similar between two groups, except for body weights (P = 0.002). The first morphine demand time was significantly longer in Group L (P = 0.037), but the pain levels did not differ. The mean pain scores were higher in Group T in the 15 min (P = 0.036), 1 h (P = 0.020), 2 h (P = 0.001) and 4 h (P = 0.0042) after extubation. A statistically significant difference between two groups was found in calculated cumulative morphine consumptions per kilogram in the 15 min (P = 0.037), 30 min (P = 0.016), and 1 h (P = 0.004) and 2 h (P = 0.013) between two groups. There was no difference in the severity of nausea but 13 patients in Group T and five patients in Group L had vomiting (P = 0.018). Patient satisfaction was similar in the two groups.

Preoperatively administered lornoxicam 16 mg significantly prolonged the first morphine demand time, reduced postoperative morphine consumption during the first 4 h and caused significantly fewer adverse effects when compared with tenoxicam after laparoscopic cholecystectomy.

Alfentanil was reported to relax the rat aorta by direct action on the vascular smooth muscle. The aims of this in vitro study were to examine the effect of alfentanil on phenylephrine-induced contractions in the rat aorta and to determine the cellular mechanism associated with this process.

Endothelium-denuded aortic rings were suspended in order to record isometric tension. In the rings with or without 10−6 mol naloxone or 10−5 mol verapamil, the concentration–response curves for phenylephrine and potassium chloride were generated in the presence or absence of alfentanil (10−6, 5 × 10−5, 10−4 mol). In the rings exposed to a calcium-free isotonic depolarizing solution, the contractile response induced by the addition of calcium was assessed in the presence or absence of alfentanil (5 × 10−5, 10−4 mol).

Alfentanil (5 × 10−5, 10−4 mol) attenuated (P < 0.05) the phenylephrine-induced contraction in the ring with or without 10−6 mol naloxone but had no effect on the phenylephrine-induced contraction in the rings pretreated with verapamil. Alfentanil (5 × 10−5, 10−4 mol) produced a significant rightward shift (P < 0.01) in the potassium chloride dose–response curve, and attenuated the contractile response (P < 0.001) induced by calcium in the calcium-free isotonic depolarizing solution in a dose-dependent manner.

A supraclinical dose of alfentanil attenuates the phenylephrine-induced contraction via an inhibitory effect on calcium influx by blocking the l-type calcium channels in the rat aortic vascular smooth muscle.

The purpose of this study was to examine the effects of intravenous dexmedetomidine on the duration of bupivacaine-induced epidural anaesthesia and level of wakefulness and the respective side-effects.

Sixty ASA I–II patients were included in the study. Consecutive patients were allocated to groups according to the last digit (odd/even) of their admission numbers. All patients had epidural anaesthesia with bupivacaine 0.5% performed by the same experienced anaesthesiologist. In the first group, the patients were administered intravenous dexmedetomidine infusion just after the epidural block and continued during the operation, while those in the second group were administered physiologic saline infusion at the same amount and duration.

The recovery time of sensory block was significantly longer in the first group. The bispectral index values were lower in the first group than in the second. Also, heart rate was significantly lower in Group I than in Group II. Regarding side-effects, shivering was significantly less frequent in the first group, whereas there was a significant increase in the requirement of atropine in the first group as dexmedetomidine caused bradycardia.

Intravenous administration of dexmedetomidine prolonged the duration of epidural anaesthesia, provided sedation and had few side-effects.

The objective of this study was to determine the intracranial, cardiovascular and respiratory changes induced by conversion to high-frequency oscillator ventilation from conventional mechanical ventilation at increasing airway pressures.

In this study, 11 anaesthetized sheep had invasive cardiovascular and intracranial monitors placed. Lung injury was induced by saline lavage and head injury was induced by inflation of an intracranial balloon catheter. All animals were sequentially converted from conventional mechanical ventilation to high-frequency oscillator ventilation at target mean airway pressures of 16, 22, 28, 34 and 40 cm H2O. The mean airway pressure was achieved by adjusting positive end expiratory pressure while on conventional mechanical ventilation, and continuous distending pressures while on high-frequency oscillator ventilation. Cerebral lactate production, oxygen consumption and venous oximetry were measured and analysed in relation to changes in transcranial Doppler flow velocity. Transcranial Doppler profiles together with other physiological parameters were measured at each airway pressure.

Cerebral perfusion pressure was significantly lower during high-frequency oscillator ventilation than during conventional mechanical ventilation (CMV: 45, 34, 22, 6, 9 mmHg vs. HFOV: 33, 20, 19, 5, 5 mmHg at airway pressures mentioned above, P = 0.02). Intracranial pressure and cerebrovascular resistance increased with increasing intrathoracic pressures (P = 0.001). Cerebral metabolic indices demonstrated an initial increase in anaerobic metabolism followed by a decrease in cerebral oxygen consumption progressing to cerebral infarction as intrathoracic pressures were further increased in a stepwise fashion. Arterial PaCO2 increased significantly after converting from conventional mechanical ventilation to high-frequency oscillator ventilation (P = 0.001). However, no difference was observed between conventional mechanical ventilation and high-frequency oscillator ventilation when intracranial pressure, metabolic and transcranial Doppler indices were compared at equivalent mean airway pressures.

The use of high positive end expiratory pressure with conventional mechanical ventilation or high continuous distending pressure with high-frequency oscillator ventilation increased intracranial pressure and adversely affected cerebral metabolic indices in this ovine model. Transcranial Doppler is a useful adjunct to intracranial pressure and intracranial venous saturation monitoring when major changes in ventilation strategy are adopted.