There are only limited data on sevoflurane minimum alveolar concentration (MAC) in rats. This study was designed to determine the minimum alveolar concentration value for sevoflurane in younger and older rats. Minimum alveolar concentration determination was performed in spontaneously breathing animals, 9-week-old rats (younger, n = 8) and more than 13-month-old rats (older, n = 8). Rats were instrumented with a silastic catheter in the abdominal aorta via the femoral artery to allow for arterial blood gas sampling. Subsequently, minimum alveolar concentration for sevoflurane was determined in 40 younger and 38 older rats. Minimum alveolar concentration for sevoflurane in younger rats was significantly higher than in the older rats (2.68 ± 0.19 vs. 2.29 ± 0.19, P < 0.001). Subgroup analysis indicated that minimum alveolar concentration for sevoflurane was not affected by the presence of an arterial catheter in the abdominal aorta (younger, 2.75 ± 0.08 vs. 2.67 ± 0.21; older, 2.23 ± 0.19 vs. 2.30 ± 0.18). Minimum alveolar concentration is profoundly affected by the age of the animal, but not by limited instrumentation.

In this study the antiemetic effects of droperidol, ondansetron and their combination were evaluated in 160 ASA Grade I and II children undergoing surgery for strabismus, who were randomly assigned to one of four groups: Group D received droperidol 75 μg kg−1, group O ondansetron 0.1 mg kg−1, group D + O received both droperidol 75 μg kg−1 and ondansetron 0.1 mg kg−1, and group N NaCl as placebo. Emesis within the first 24 h occurred in 95.0% of the children with placebo medication, compared with 32.5% (D), 40.0% (O) and 45.0% (D + O) in the groups with antiemetic prophylaxis. The differences between group N and all other groups were significant (P < 0.001). However, there were no statistically significant differences between the groups D, O and D + O. It is concluded that droperidol (75 μg kg−1) and ondansetron (0.1 mg kg−1) both significantly reduce PONV in children undergoing surgery for strabismus. Neither ondansetron, nor the combination D+O were superior to droperidol alone.

The microbiological contamination of 250 breathing system tubes after use in anaesthesia circle systems with reduced fresh gas flow was investigated. The lungs of 50 patients were ventilated without any filtering device between the endotracheal tube and the Y-piece. A total of 51, 49 and 100 patients, respectively, were given different types of heat and moisture exchanger with electret filters (HMEF). With no filtering device the tubing system was contaminated by micro- organisms originating from the patient's tracheal secretion in 13% of the patients. In contrast, no bacterial migration into the tubing system was detected when any of the investigated HMEF-devices were used. We therefore conclude that heat and moisture exchangers with electret filters prevent contamination of the anaesthesia breathing system with microorganisms from the patients airways.

Remifentanil is an ultrashort acting mu opioid, well suited to total intravenous (i.v.) anaesthesia. Pain immediately following emergence from anaesthesia is a potential problem because of the rapid offset. This study investigated the transition from remifentanil/propofol total intravenous anaesthesia to post-operative analgesia with epidural or patient controlled analgesia morphine in 22 patients undergoing major abdominal surgery. A remifentanil post-operative infusion initiated during emergence was titrated in the recovery room for 30 min, at which time 14% of patients had a pain score of 2 and 86% had pain scores of 0 or 1 (0 = no pain; 1 = mild pain; 2 = moderate pain; 3 = severe pain), at a mean infusion rate of 0.086 mug kg −1 min −1 . A smooth transition was then made to either epidural analgesia or patient controlled analgesia with morphine; pain scores were not significantly changed during the transition. Nausea occurred in 16 of the 22 patients, but only following administration of morphine. Epidural analgesia produced significantly lower pain scores on the surgical ward compared with patient controlled analgesia.

The most common indication for employing the fibreoptic technique for intubation is when a difficult intubation is anticipated. It may also be used when intubation unexpectedly proves difficult with a rigid laryngoscope in anaesthetized patients. However, failures with orotracheal fibreoptic intubation have been reported in up to 9.5% of cases, although only two possible equipment related causes of intubation difficulties have been identified. The Berman intubating airway and the Ovassapian intubation airway in fibreoptic orotracheal intubation have been compared in 65 patients. The study was randomized and for fibreoptic endoscopy each patient served as his or her own control. The results indicate that both airways can be used for orotracheal fibreoptic intubation in anaesthetized patients. The Berman airway offers easier visualization of the vocal cords than the Ovassapian airway, provided that the Berman airway is of an adequate size and positioned in the midline. Upon impingement of the intubation tube, completing the tracheal intubation is more difficult with the Berman airway than the Ovassapian airway.

Forty-three ASA Grade I patients scheduled for elective abdominal surgery received at random either 25% or 50% inspired oxygen for intra-operative mechanical ventilation lasting 4–6 h. Pulse oximetry was monitored continuously. Venous admixture was assessed from the PaO2/FIO2 ratio and was measured twice intra-operatively: at the time of incision, and during surgical wound closure. PaO2 was measured 1 h after extubation having breathed room air for 10 min, if tolerated. The patients in the two groups were similar in regard to general characteristics, and had similar operations. Patients given oxygen 50% had operations that lasted longer, which made the trial more sensitive. The inspired oxygen did not affect pulmonary gas exchange either within each group or between groups under the conditions of the study. In no patient did pulse oximetry record an oxygen saturation below 95% intra-operatively.

Desflurane has been reported to cause tachycardia and hypertension during induction of anaesthesia. The aim of this study was to determine the effects of desflurane on cerebral blood flow (CBF) velocity using transcranial Doppler ultrasonography in a setting that closely resembled usual clinical practice. In two groups (n = 9 in each) ASA Grade I or II patients, anaesthesia was induced with etomidate and vecuronium intravenously (i.v.), sufentanil (0.3 μg kg−1 i.v.) was added in the second group. Patients were ventilated by facemask for 2 min before desflurane was administered in steps of 0.5 MAC min−1 until 1.5 MAC was reached and maintained for 7 min. Haemodynamic variables and CBF velocity in the middle cerebral artery (MCA) were monitored throughout the study period. In group 1 heart rate increased to 108 ± 2 b.p.m. (37% increase) whereas MAP increased to 114 ± 6 mmHg after administration of desflurane (33% increase). CBF velocity increased to 86 ± 7 cm s−1 (69% increase). In group 2 no significant changes in systemic haemodynamic responses were measured after desflurane administration; however, CBF velocity increased to 73 ± 5 cm s−1 (59% increase). The results indicate that desflurane increases CBF velocity concurrently with induction of tachycardia and hypertension. Although sufentanil and N2O attenuate the systemic haemodynamic alterations caused by desflurane, the CBF velocity increases. These data suggest that the abrupt addition of desflurane may have adverse consequences in patients at risk for intracranial hypertension.

The purpose of this study was to assess the value of lignocaine biotransformation into monoethylglycinexylidide (MEGX) and conventional liver function tests in the early post-operative period as an indicator of graft function and as a diagnostic tool for complications after hepatic transplantation. Monoethylglycinexylidide formation, plasma bilirubin, aspartate aminotransferase (ASAT), alanine amino- transferase (ALAT), factor V index (FVI) and prothrombin time index (PTI) were measured in 71 patients undergoing 80 liver transplantations respectively at 12 (T1), 24 (T2), 48 (T3) and 72 h (T4) after liver graft revascularization. Patients were divided into two group according to the post-operative outcome. Patients with favourable outcome (n = 59) had significantly higher monoethylglycinexylidide synthesis, higher factor V index and prothrombin time index plasma concentrations, lower bilirubin, ASAT and ALAT plasma concentration (P < 0.0001 at T2 and T3) than those with complicated time course (n = 21). Monoethylglycinexylidide synthesis was the best discriminant of a favourable outcome, whereas bilirubin and ALAT concentrations were associated with complications (bilirubin for primary non function [PNF], ALAT for acute rejection). Thus, the combination of parameters at T2 was a very efficient predictor of primary non function, acute rejection and an uncomplicated time course.

The purpose of this experimental study was to find out whether central haemodynamic activity influences the precision of the ethanol method used to monitor fluid absorption during endoscopic surgery. Today, the nomograms used together with this monitoring method indicate that increasing breath ethanol values reflect progressively larger absorption volumes regardless of the haemodynamic situation. Cardiac output was measured by ultrasound-Doppler and compared with the concentrations and pharmacokinetics of ethanol in the breath during and after 13 intravenous (i.v.) infusions of 15 mL kg−1 of irrigating fluid containing 1% of ethanol in nine healthy male volunteers. The results show that the peak ethanol concentration increases with cardiac output. This can probably be explained by the shorter time needed for the blood to reach and to return from well perfused tissues, thereby prolonging the apparent rate of distribution to poorly perfused tissues. It is concluded that a hyperkinetic circulation causes the ethanol monitoring method to indicate larger absorption volumes.

Intra-operative segmental wall motion abnormalities (SWMA) detected by transoesophageal echocardio- graphy (TOE) have been shown to be a sensitive indicator of myocardial ischaemia. To determine the incidence and characteristics of segmental wall motion abnormalities and to relate these changes to peri-operative myocardial ischaemia, biplane TEE, electrocardiogram (ECG) (II + V5) and pulmonary capillary wedge pressure (PCWP) were continuously monitored in 62 consecutive patients with ischaemic heart disease undergoing non-cardiac surgery. Short-axis view at mid-papillary level in transverse scan (T-scan) and long-axis in longitudinal (L-scan) two-chamber view were used for wall motion analysis. New segmental wall motion abnormalities were detected in 16 of 64 patients (25%) using biplane transoesophageal echocardiography. Monoplane transoesophageal echocardiography showed a sensitivity of 75% and a specificity of 100%, electrocardiogram two lead showed a sensitivity of 56% and a specificity of 98%, whereas pulmonary capillary wedge pressure had a sensitivity of 25%, and a specificity of 93% and pressure rate quotient (PRQ) < 1 demonstrated sensitivity of 19% and a specificity of 92% in the detection of myocardial ischaemia. It is concluded that the long-axis view of the left ventricle provides additional information for the detection of segmental wall motion abnormalities. Neither changes in haemodynamic performance nor in electrocardiography leads II and V5 match those of transoesophageal echocardiography for the identification of myocardial ischaemia.

The effect of a single pre-operative oral dose of controlled release diclofenac sodium on post-operative pain after minor gynaecological surgery was investigated. Fifty-two women took part in a double-blind controlled study. Pain was assessed by visual analogue scale (VAS), a four-point verbal rating score, and the requirement for post-operative analgesia. Those patients who received diclofenac had significantly less post-operative pain than the placebo group up to 2 h after surgery.

The incidence of bacterial colonization of central venous catheters using a standard polyurethane catheter was compared with that using an antiseptic (silver sulphadiazine and chlorhexidine) impregnated catheter in a group of patients with thoracic organ transplantation. Colonization was reduced from 25 of 35 standard catheters to 10 of 44 study catheters (P < 0.002), a 68 % reduction. Similarly, the incidence of concomitant infection, by the same organism at another site was reduced from 10 of 35 standard catheters to 4 of 44 study catheters (P < 0.03), a 63% reduction.

Patients expected to need at least three units of blood for their elective cardiovascular or orthopaedic surgery, were allocated randomly to receive intravenous (i.v.) Epoetin alfa 600 IU kg−1 (n = 27), 300 IU kg−1 (n = 30) or placebo (n = 23), on days 1, 4 and 7. Provided haemoglobin ≥ 11 g dL−1, one unit of blood was collected on days 1, 4, 7, 11 and 14. Iron supplementation was given throughout the study. Surgery was scheduled between days 18 and 21. Significantly more patients treated with Epoetin alfa (100% for 600 IU kg −1 ; 97% for 300 IU kg−1) were able to donate ≥ 4 units of blood compared with placebo (78%) (P = 0.011 and P = 0.032). No significant differences were seen in total patient exposure to homologous blood (7.4%, 3.3% and 17.4%, respectively). Mean red cell volume donated (P = 0.005 for 600 IU kg−1 ; P = 0.158 for 300 IU kg−1 both vs. placebo) and production (P < 0.001 and P = 0.012, respectively) were dose related. Twenty-four patients became iron deficient. No differences in the incidence of adverse events were seen between the groups.

The effects of acute haemodilution, during prostaglandin E1 (PGE1)-induced hypotension, on the blood coagulation-fibrinolysis system were studied in 40 patients undergoing hip surgery. The patients were randomly divided into four groups of 10 patients each; Group A (control) received no induced hypotension or haemodilution, group B received hypotension alone, group C received haemodilution alone and group D received the combination of induced hypotension and haemodilution. Haemodilution in groups C and D was produced by drawing ≈ 1000 mL of blood and replacing it with the same amount of 6% hydroxyethyl starch. Induced hypotension in groups B and D was conducted with PGE1 and mean blood pressure was maintained at 55 mmHg. The mean dosage of PGE1 was 648 mug in group B and 661 mug in group D. In the control and PGE1-induced hypotension groups there was no significant change in platelet count (PLT), prothrombin time (PT), activated partial thromoplastin time (aPTT), fibrinogen (FIB), antithrombin-III (AT-III) or plasminogen (PLG). Haemodilution alone caused significant decreases in PLT (−43%), PT (+21%), FIB (−33%), AT-III (−21%) and PLG (−27%), and a significant increase in aPTT (+26%), whereas the combination of PGE1-induced hypotension did not cause any further change in these parameters. Serum-fibrin degradation products (FDP) significantly increased (+300%) and PLG significantly decreased (−30%) after surgery in all groups. It can be concluded that acute haemodilution to a haematocrit value of 22 ± 2% causes a slight coagulopathy, which is not enhanced when combined with PGE1-induced hypotension.

The peri-operative management of the only surviving case, to date, of living-related small bowel transplantation is described. The anaesthetic technique was chosen to optimize hepato-splanchnic blood flow. Peri-operative splanchnic blood flow was measured and alterations in flow with changes in inotropic agents and volume loading monitored. There appears to be a role for the use of dopexamine and aggressive volume loading.

A healthy 22-year-old man received an initial injection of 12 mL of lignocaine/bupivacaine solutions (2 mL test, then 10 mL) into an epidural catheter. This produced a satisfactory regional blockade that seemed to be epidural but, when a supplementary 6 mL injection was given 1 h later, the patient developed impaired motor function as far as the upper cranial nerves, with loss of pinprick sensation to the shoulder. The emergence of fluid dribbling freely from the catheter prompted measurement of the pressure, which was 36 mmHg. The fluid was proved not to be cerebrospinal fluid (CSF) by the absence of glucose (on dextrostix), by the appearance of turbidity with added thiopentone, and later by microscopy. Slow aspiration of 7 mL of the presumed injectate reduced the pressure in the catheter to 8 mmHg, which promptly reversed the additional excessive blockade, allowing surgery to proceed uneventfully. The retrieval of injectate argues strongly that the catheter tip had found its way subdurally, and the promptness of the reversal with aspiration argues for a mechanical rather than a pharmacological cause for the extensive neurological dysfunction after the second injection. Pressure measurement and aspiration may be helpful in other similar cases.

Extracorporeal shock wave lithotripsy using a spark gap generator is contraindicated in patients with complete atrioventricular heart block. A case of a patient with such a heart block, who successfully underwent renal lithotripsy, without cardiac pacemaker, is reported.

Chondronecrosis of the cricoid cartilage is a rare complication of intubation. The records of two children were reviewed. An 8-month-old girl with myelomonocytic leukaemia developed chondronecrosis 10 days after a 2-day period of ventilation. A 4-year-old girl comatose after poisoning by the histamine antagonist, alimemazine, developed chondronecrosis after a 2-day period of intubation. The complication was suspected when extubation led to dyspnoea owing to laryngeal stridor and was confirmed by direct laryngoscopy. We review the development of the condition, the causative factors, treatment and prevention.