Patients who awake from sevoflurane anaesthesia with symptoms of agitation may have some underlying functional substrate that is sensitive to the low concentrations of anaesthetic encountered during emergence. One candidate for such a substrate could be neurocircuitry implied in the pathophysiology of both agitation and movement disorders with hyperactivity. We postulated that hyperactive animals would show a further increase in activity in the presence of low concentrations of volatile anaesthetics, such as sevoflurane.

To confirm our hypothesis, we examined the effects of two subanaesthetic concentrations of sevoflurane, isoflurane and halothane (0.1 and 0.2 MAC (minimum alveolar concentration)) on spontaneous activity in N-methyl-d-aspartate receptor GluRε1 subunit knockout mice exhibiting locomotor hyperactivity in a novel environment and compared these results with those for wild-type controls. We also compared the effects of anaesthetic concentrations of sevoflurane (1.2 MAC) on mice activity during postanaesthesia recovery.

Out of the three anaesthetics used, only sevoflurane administered at 0.1 MAC caused a significantly different response between the two experimental groups. Exposure to this subanaesthetic concentration of sevoflurane reduced the activity of wild-type mice, whereas mutant animals showed a further increase in hyperactivity. The effects of 1.2 MAC sevoflurane anaesthesia on mice activity during postanaesthesia recovery also differed significantly between the two genotypes. Exposure to anaesthetic concentrations of sevoflurane had a sedative effect on wild-type mice, whereas mutant mice preserved their high levels of activity upon emergence from the anaesthesia.

The presence of an inherent anomaly in mutant mice that becomes more manifest during exposure to 0.1 MAC sevoflurane and is still present after the emergence from sevoflurane anaesthesia suggests the presence of and necessitates a search for some putative substrate that may, by analogy, underlie emergence agitation in the clinical setting.

Analgesia and sedation are usually required during extracorporeal shock wave lithotripsy. In the present study, the recovery time and effectiveness of sedation and analgesia of dexmedetomidine was compared with a midazolam/fentanyl combination in outpatient extracorporeal shock wave lithotripsy.

Forty-nine patients scheduled for outpatient extracorporeal shock wave lithotripsy were randomly assigned to two groups: a dex group (n = 25; dexmedetomidine 1 μg kg−1 loading dose followed by dexmedetomidine 0.2 μg kg−1 h−1) and a control group (n = 24; midazolam 0.05 mg kg−1 and fentanyl 1 μg kg−1). Recovery time, rescue analgesics (fentanyl 25 μg) and sedatives (midazolam 1 mg), and patients’ satisfaction rates were recorded.

The two groups were similar regarding patient characteristics and procedure-related details (P > 0.05). Recovery time was significantly prolonged in the dex group when compared with the control group (116.4 ± 39.3 vs. 50.8 ± 19.8 min, respectively, P < 0.001). The percentage of patients requiring rescue doses of fentanyl and the applied doses were significantly higher in the dex group than in the control group (96% vs. 67%, P = 0.01; and 69.0 ± 31.7 vs. 38.8 ± 42.9 μg, respectively, P = 0.007). More patients in the dex group received rescue midazolam (96% vs. 58%, P = 0.002). More patients in the control group were highly satisfied with their sedation/analgesia (83% vs. 56%, P = 0.038).

Dexmedetomidine was associated with a longer recovery time than a midazolam/fentanyl combination when used for sedation and analgesia during outpatient extracorporeal shock wave lithotripsy in this study. The incidence of rescue sedative and analgesic need was also significantly higher when dexmedetomidine was used.

We have investigated whether, after major abdominal surgery, the addition of remifentanil to tramadol for intravenous patient-controlled analgesia improved analgesia and lowered pain scores, compared to a patient-controlled analgesia containing only tramadol.

Sixty-two patients were allocated randomly to receive an intravenous patient-controlled analgesia with tramadol alone (T), or tramadol plus remifentanil (TR), in a double-blind randomized study. Whenever patients complained of pain, they were allowed to use bolus doses of tramadol (0.2 mg kg−1) or tramadol (0.2 mg kg−1) plus remifentanil (0.2 μg kg−1) mixture every 10 min without a time limit and background infusion. Discomfort, sedation, pain scores, total and bolus patient-controlled analgesia tramadol consumption, and side-effects were recorded for up to 24 h after the start of patient-controlled analgesia.

Pain scores at rest were statistically significantly lower in the TR group at 6, 12 and 24 h than in T group (P < 0.05). Pain scores at movement and patient comfort scores were also found to be significantly lower in the TR group at 2, 6, 12 and 24 h than in the T group (P < 0.05). Although the TR group consumed less tramadol, there were no statistically significant differences in the cumulative tramadol consumptions between the groups at any time. However, the number of patients requiring rescue analgesia and average supplementary doses used was significantly higher in the T group than in the TR group (P < 0.05).

After major abdominal surgery, adding remifentanil (0.2 μg kg−1) to tramadol (0.2 mg kg−1), with 10-min lockout times, for patient-controlled analgesia offered better postoperative pain relief and patient comfort, without causing any sedation or respiratory depression.

Vasoactive substances such as histamine, acetylcholine or ATP increase the [Ca2+]i of endothelial cells, which leads to the activation of nitric oxide synthase (eNOS). The NO produced by this enzyme relaxes the underlying smooth muscle. Evidence suggests that eNOS activation is dependent on agonist-induced Ca2+ entry. Recently we have shown that in human endothelial cells (HUVEC), this Ca2+ entry is sensitive to isoflurane. The objective here was to study the mechanism by which volatile anaesthetics can depress the histamine-induced Ca2+ entry into HUVEC cells.

HUVECs on coverslips were loaded with the Ca2+ indicator Fluo-3 and inserted in a gastight, temperature-controlled perfusion chamber. Excitation was at 488 nm and fluorescence signals were monitored with a confocal laser scanning microscope (MRC1024, Biorad). Direct measurement of the Ca2+ influx was with Mn2+ as surrogate for calcium at 360 nm in cells loaded with Fura-2.

Addition of histamine induces a biphasic [Ca2+]i increase consisting of Ca2+ release from internal stores and a Ca2+ influx from the external medium (plateau phase). The plateau phase was dose-dependently inhibited by enflurane and sevoflurane (13.7 resp. 21.9% inhibition by 1 MAC anaesthetic). Direct measurement of the Ca2+ influx using the Mn2+ quench of the Fura-2 fluorescence gave similar results. The inhibition of the anaesthetics was not reduced by inhibition of the cGMP pathway, inactivation of protein kinase C, depolarization of the cells or the presence of specific Ca2+-dependent K+ channel inhibitors. Interestingly, unsaturated fatty acids inhibit the histamine-induced Ca2+ influx in a similar way as the volatile anaesthetics.

Volatile anaesthetics dose-dependently inhibit the histamine-induced Ca2+ influx in HUVECs by a mechanism that may involve unspecific perturbation of the lipid bilayer.

Patients with impaired renal function are at risk of developing renal dysfunction after abdominal aortic surgery. This study investigated the safety profile of a recent medium-molecular-weight hydroxyethyl starch (HES) preparation with a low molar substitution (HES 130/0.4) in this sensitive patient group.

Sixty-five patients were randomly allocated to receive either 6% hydroxyethyl starch (Voluven®; n = 32) or 3% gelatin (Plasmion®; n = 33) for perioperative volume substitution. At baseline, renal function was impaired in all study patients as indicated by a measured creatinine clearance < 80 mL min−1. The main renal safety parameter was the peak increase in serum creatinine up to day 6 after surgery.

Both treatment groups were compared for non-inferiority (pre-defined non-inferiority range hydroxyethyl starch < gelatin + 17.68 μmol L−1 or 0.2 mg dL−1). Other renal safety parameters included minimum postoperative creatinine clearance, incidence of oliguria and adverse events of the renal system. Baseline characteristics, surgical procedures and the mean total infusion volume were comparable. Non-inferiority of hydroxyethyl starch vs. gelatin could be shown by means of the appropriate non-parametric one-sided 95% CI for the difference hydroxyethyl starch − gelatin [−∞, 11 μmol L−1]. Oliguria was encountered in three patients of the hydroxyethyl starch and four of the gelatin treatment group. One patient receiving gelatin required dialysis secondary to surgical complications. Two patients of each treatment group died.

As we found no drug-related adverse effects of hydroxyethyl starch on renal function, we conclude that the choice of the colloid had no impact on renal safety parameters and outcome in patients with decreased renal function undergoing elective abdominal aortic surgery.

With the increasing demand for one-lung ventilation in both thoracic surgery and other procedures, identifying the correct placement becomes increasingly important. Currently, endobronchial intubation is suspected based on a combination of auscultation and physiological findings. We investigated the ability of the visual display of airflow-induced vibrations to detect single-lung ventilation with a double-lumen endotracheal tube.

Double-lumen tubes were placed prior to surgery. Tracheal and endobronchial lumens were alternately clamped to produce unilateral lung ventilation of right and left lung. Vibration response imaging, which detects vibrations transmitted to the surface of the thorax, was performed during both right- and left-lung ventilation. Geographical area of vibration response image as well as amount and distribution of lung sounds were assessed.

During single-lung ventilation, the image and video obtained from the vibration response imaging identifies the ventilated lung with a larger and darker image on the ventilated side. During single-lung ventilation, 87.2 ± 5.7% of the measured vibrations was detected over the ventilated lung and 12.8 ± 5.7% over the non-ventilated lung (P < 0.0001). It was also noted that during single-lung ventilation, the vibration distribution in the non-ventilated lung had a majority of vibration detected by the medial sensors closest to the midline (P < 0.05) as opposed to the midclavicular sensors when the lung is ventilated.

During single-lung ventilation, vibration response imaging clearly showed increased vibration in the lung that is being ventilated. Distribution of residual vibration differed in the non-ventilated lung in a manner that suggests transmission of vibrations across the mediastinum from the ventilated lung. The lung image and video obtained from vibration response imaging may provide useful and immediate information to help one-lung ventilation assessment.

Blood oxygen concentration decrease may be associated with haemostatic impairments. We aimed to study the effect of oxygen decrease in a rabbit model of thrombosis and bleeding.

A total of 44 rabbits were anaesthetized, ventilated and monitored for blood pressure, blood arterial gas, temperature and carotid blood flow. The Folts model was used: a stenosis (75%) and an injury were carried out on the carotid artery, inducing thrombosis. Blood flow decreased as thrombus size increased until the pressure gradient was such that the thrombus was released and local arterial blood flow was suddenly restored. This is known as a cyclic flow reduction. After counting baseline cyclic flow reductions during a 20-min period (P1), rabbits were randomized blindly to one of three groups: hyperoxic, FiO2=100%; normoxic, FiO2 was decreased to obtain a PaO2 between 80 and 120 mmHg; hypoxic, PaO2 < 80 mmHg. Then CFRs were recorded over a second 20-min period (P2). At the end of the experiment, a hepatosplenic section was done and the amount of blood loss was recorded. After each period, the following parameters were measured: blood gas, ear-immersion bleeding time, haemoglobin, platelet count, prothrombin time, activated partial thromboplastin time and fibrinogen.

Oxygen decrease during hypoxic and normoxic periods was associated with a decrease in cyclic flow reductions. Bleeding time increased in the hypoxic group unless hepatosplenic bleeding remained stable. A slight increase in activated partial thromboplastin time was observed in the normoxic and hypoxic groups.

An abrupt decrease in oxygen administration was responsible for an antithrombotic effect. Increase in bleeding time occurred during hypoxia. No clinically relevant variation of any haemostasis parameters was observed.

To establish whether caudal with ketamine or penile block provide superior postoperative analgesia for paediatric circumcision.

This was a single centre, prospective, randomized, controlled, double-blind trial. Forty males (aged between 18 months and 16 yr) were randomized to receive either a penile block using 0.25 mL kg−1 0.5% bupivacaine (Group P), or a caudal block using 0.5 mL kg−1 0.25% bupivacaine with 0.5 mg kg−1 ketamine (Group C). All of them were given a standard anaesthetic and rectal paracetamol 40 mg kg−1 and diclofenac 1–1.5 mg kg−1. Postoperative pain scores were assessed in recovery and the time to first analgesia, micturition and walking were recorded.

There were no failures in either group. The time to first analgesia was longer in Group C (C median = 459 min, interquartile range 374–553 min; P median = 374 min, interquartile range 224–507 min; P < 0.05). There was a delay in time to walking in Group C (C median = 162 min, interquartile range 119–208 min; P median = 120 min, interquartile range 92–132 min; P < 0.05). There was no difference between the groups in time to waking or micturition, or the incidence of vomiting, abnormal behaviour or bleeding.

Caudal bupivacaine with ketamine and penile block both provide effective postoperative analgesia for circumcision when given with non-steroidal anti-inflammatory drugs. This study shows that caudal bupivacaine with ketamine provides a longer duration of analgesia than penile block, but also causes delay in walking.

We investigated cerebrospinal fluid characteristics in patients with and without diabetes mellitus and the influences that changes in these characteristics have on sensory and motor block when spinal anaesthesia is performed.

We included 44 patients in each study group. All received spinal administration of 15 mg of 0.5% isobaric bupivacaine. Blood and cerebrospinal fluid were analysed for glucose, total protein, urea, albumin, immunoglobulin G, sodium, chloride, potassium, calcium, magnesium and osmolarity as well as the performance of the local anaesthetic from establishment until complete regression of sensory and motor block.

The cerebrospinal fluid of the two groups differed significantly (P < 0.05) in the levels of total protein, albumin, immunoglobulin G, glucose and osmolarity. Sensory and motor block was established more rapidly in the diabetic group (P < 0.05), and the total duration from maximum block until regression to two dermatomes was greater (P < 0.05), as was the complete regression from sensory and motor block (P < 0.05).

This study shows that diabetes mellitus has an influence on sensory and motor block after the administration of spinal isobaric bupivacaine.

There are no clinical studies that compare epidural infusion of ropivacaine and levobupivacaine in patients undergoing lung surgery. The aim of this prospective, randomized double-blind study was to evaluate the efficacy and safety of two commercially available solutions of ropivacaine (0.2% w/v) and levobupivacaine (0.125% w/v) when administered by continuous epidural infusion together with sufentanil in patients undergoing lung surgery.

After obtaining informed consent, 54 patients, ASA physical status I–III undergoing lung resection, were enrolled. Patients were randomly assigned to two groups in which analgesia was performed by continuous thoracic epidural infusion of ropivacaine 0.2% w/v (Group R) or levobupivacaine 0.125% w/v (Group L) with or without sufentanil 1 μg mL−1. After a test and a loading dose of each drug for the respective group, continuous epidural infusion, set at 5 mL h−1, began. General anaesthesia was standardized. In the recovery room, patients were provided with intravenous morphine patient-controlled analgesia. Visual analogue scale at rest and when coughing, rescue patient-controlled analgesia morphine amount, haemodynamics, sensory and motor block, sedation, nausea and vomiting, patient satisfaction score, were evaluated within 48 h.

The two groups were similar regarding patient characteristics, quality of analgesia, level of sensory block, morphine consumption and satisfaction score. Postoperative haemodynamic profile was stable in all the patients. Minor side-effects occurred with a similar incidence. Motor block was not seen.

Equivalent volumes of ropivacaine (0.2% w/v) and levobupivacaine (0.125% w/v) provided similar static and dynamic analgesia with similar incidence of minor side-effects after thoracotomy.

This study examined attitudes and views held by stakeholders regarding their experience of training in spinal anaesthesia. The aim was to identify key factors related to learning and teaching processes which were perceived to influence the acquisition of competence in spinal anaesthesia.

The study was carried out at a busy acute tertiary referral teaching hospital over a period of 1 yr. It applied a qualitative research approach in three phases, namely (i) completion of preliminary questionnaires, (ii) completion of focused questionnaires and (iii) focus group discussions.

Five factors were perceived to be critical ‘determinants of learning’: (i) the existence of a formal, structured training programme; (ii) time constraints/theatre efficiency; (iii) trainer–trainee interaction; (iv) patient safety/trainee/trainer stressors; and (v) visualization of the anatomy and procedure.

The study highlighted the need for a formal and structured training programme in spinal anaesthesia, through which many of the undesirable and discouraging factors (such as stress, adverse trainer–trainee interaction and time constraints) identified in the study could be minimized. Further studies are needed to validate the results in other hospital settings, as well as to define the relative importance of each of the proposed determinants and their interrelationships.