Fifteen patients undergoing elective thoracic surgery were studied in order to investigate the efficacy of high frequency jet ventilation of the non-dependent lung with respect to arterial oxygenation. During the study PaO2, PaCO2, arterial pressures and heart rate were recorded during ventilation of both lungs in the lateral decubitus position during one-lung ventilation and during high frequency jet ventilation of the non-dependent lung. Mean PaO2 was 28±8.75 kPa and mean PaCO2 was 5.4±0.7 kPa during control. During one-lung ventilation, PaO2 dropped to 10.8±2.57 kPa and PaCO2 rose to 6.3±0.9 kPa. With high frequency jet ventilation to the non-dependent lung, mean PaO2 increased to 25±6.75 kPa and PaCO2 decreased to 5.16±0.9 kPa respectively. Arterial pressures and heart rate remained stable during the study period. In conclusion high frequency jet ventilation of the non-dependent lung was effective in providing arterial normoxaemia and normocapnia during one-lung ventilation.

The authors compared the acceptance and efficacy of rectal and nasal administration of midazolam (MDZ) for premedication. Ninety-five ASA I and II paediatric patients (8 months to 12 years) scheduled for elective surgery were randomly allocated to two groups. Group R received 0.3 mg kg−1 of rectal midazolam (in 5mL saline). Group N received 0.2 mg kg−1 of nasal midazolam (5 mg ml−1). Both groups were divided in two subgroups according to age (group RA ( ≤ 6 years, n = 33), group RB ( > 6 years, n = 18), group NA ( ≤ 6 years, n = 28), group NB ( > 6 years, n = 16)). At the time of premedication, tolerance to the administration was confirmed. Twenty min after rectal or 10 min after nasal administration the quality of sedation was recorded. The nasal midazolam, in commonly used dosages, induced a sedation similar to that following rectal administration with a shorter delay of onset. Nasal administration was more often painful than rectal administration. Swallowing (nasal midazolam) and concerns about modesty (rectal midazolam) were more frequent in older children. Because of its poor tolerance, nasal premedication should be reversed for cases where there is no alternative. Rectal premedication should be avoided in older children.

The analgesic efficacy of tenoxicam, a newer injectable non-steroidal anti-inflammatory drug, for post-operative analgesia after abdominal or orthopaedic surgery in ASA Grade I/II patients is reported. Two hundred and fifty-six patients received a single dose of tenoxicam 40 mg intravenous (i.v.) at the end of surgery and this was repeated 24 h later. These patients were compared, with respect to pain or adverse events, with 258 patients that received placebo. All patients were monitored for the next 72 h. Overall, tenoxicam provided reliable analgesia with comparable pain scores at rest, moving and coughing. The cumulative rescue PCA-morphine consumption was always lower in the tenoxicam treated patients and was most marked at 4 and 24 h after the second injection of tenoxicam. This effect was more pronounced after abdominal surgery. The intravenous administration of tenoxicam was associated with a low incidence of adverse events and a high tolerability.

This study was designed to investigate the incidence of critical events in breathing following light general anaesthesia compared with normal sleep during the first 12 h after transfer from the recovery room. There were no significant differences in the incidence of apnoea or desaturation episodes between normal sleep and the post-operative recovery period. There was a close correlation between the pre-operative and post-operative incidence of apnoea (r = 0.93), pre-operative and post-operative desaturation periods (r = 0.81), pre-operative and post-operative mean SpO2 values (r = 0.54) and pre-operative and post-operative minimal SpO2 values (r = 0.90) in all the patients. In the early post operative period, breathing patterns and oxygenation were similar to those observed during normal night-time sleep in elderly patients under going ophthalmological surgery.

We studied the haemodynamic changes induced by pneumoperitoneum (PP) in elderly patients with increased cardiac risk (ASA class III; n = 10; age 72.3 ± 8.8 years, mean±SD, P < 0.05; group 2) and compared the results with patients at normal risk (ASA class I, II; n = 12; age 55.6 ± 11.8 years; group 1). Thermodilution measurements were performed after induction of general anaesthesia (T1), after onset of PP (T2, intraabdominal pressure 14 mmHg) and after additional 15° head-up tilt (T3). In both groups PP, as compared with T1, induced a significant increase in mean arterial pressure (MAP, mmHg, group 1:77 ± 14 to 96 ± 18, P < 0.05/group 2:75 ± 10 to 102 ± 18, P < 0.01), mean pulmonary artery pressure (MPAP, mmHg: 15 ± 5 to 22 ± 4, P < 0.01/18 ± 3 to 25 ± 5, P < 0.01), central venous pressure (CVP, mmHg: 7 ± 2 to 15 ± 3, P < 0.01/7 ± 2 to 12 ± 2, P < 0.01), pulmonary capillary wedge pressure (PCWP, mmHg: 9 ± 4 to 16.3, P < 0.01/8 ± 2 to 15 ± 6, P < 0.01) and in systemic vascular resistance (SVR, dynes s cm−5: 1415 ± 375 to 1873 ± 412, P < 0.01/1502 ± 360 to 2067 ± 647, P < 0.01). Cardiac index (CI, L min−1 m−2: 2.3 ± 0.3 to 1.9 ± 0.3, P < 0.05/2.2 ± 0.4 to 2.2 ± 0.5 P = 0.76) and oxygen delivery index (DO2I, mL min−1 m−2: 388 ± 54 to 324 ± 61, P < 0.05/358 ± 69 to 353 ± 82, P = 0.77) decreased in group 1 but not in group 2. Heart rate, stroke index, pulmonary vascular resistance, arteriovenous oxygen content difference and oxygen consumption index were unchanged. After head-up tilt MAP (mmHg, 92 ± 15, P < 0.05/101 ± 17, P < 0.01), MPAP (mmHg, 20 ± 3, P < 0.01/22 ± 4, P < 0.05), CVP (mmHg, 12 ± 2, P < 0.01/10 ± 2, P& lt; 0.01) and PCWP (mmHg, 12 ± 3, P < 0.05/12 ± 5, P < 0.05) remained elevated compared with T1 in both groups, SVR (dynes s cm−5, 1575 ± 372, P = 0.13/1793 ± 528, P < 0.01) in group 2 only. No complications occurred. The results indicate that PP is associated with significant but relatively benign haemodynamic changes. Anaesthesia for laparoscopic cholecystectomy may be performed safely also in elderly ASA class III patients with increased cardiac risk. An adequate haemoto dynamic monitoring is recommended.

A prospective survey was conducted among an aesthesiologists to determine their criteria for excluding a patient from autologous blood donation prior to total hip prosthesis. Information on patients operated on during a 5-week period was obtained using a questionnaire, consisting of a set of possible responses to simple questions, matched with some parametric values. Sixty-eight of the 99 patients included in the survey underwent surgery without donation. Age was the main cause for exclusion (34%). The age of patients excluded because of their age alone was 75 ± 11 years (standard deviation). The age of patients excluded from donation and who did not subsequently receive homologous blood was comparable with that of patients not autotransfused but who received homologous blood (68 ± 4 vs. 69 ± 6 years, respectively). Post-operative haemoglobin concentrations were similar whether transfusion was performed or not, and regardless of the origin of blood given. Since age is no longer taken into consideration at the time of transfusion, it is likely that exclusion of a patient from autologous blood donation because of age is an arbitrary choice.

Ninety patients undergoing scheduled upper limb orthopaedic surgery were studied to determine the optimal anaesthetic dose using the ‘orthogonal two-needle technique’. The patients were randomly assigned to one of three groups to receive one of three different volumes (20, 30 and 40mL) (n = 30) of anaesthetic solution (a mixture of equal parts of 0.5% bupivacaine with adrenaline 1:200 000 and 2% lignocaine). A significant correlation was found between the volume injected and the anaesthetic spread for all tested areas. A better analgesic spread to all the major branches of the plexus was obtained when increased volumes of anaesthetic solution were injected. The comparisons between the 20 mL group and the other two groups are significant in all the tested areas, as well as the comparisons between 30 and 40 mL groups in the areas innervated by radial and musculo-cutaneous nerves. Only the area innervated by the axillary nerve showed a weaker volume-analgesia relation, confirming the elusiveness of this area to anaesthesia in the axillary approaches. The improved results observed using greater amounts of anaesthetic solution might result from a higher intrasheath pressure with disruption of sheath septa, or from a greater availability of drug for all the terminal branches of brachial plexus, or both.

The number of protocol-eligible patients, refusing to participate in a clinical trial is often not mentioned. The aim of this study is to report the number of refusers and to evaluate the reasons for not participating in a clinical study concerning post-operative pain relief and to assess the potential influence on the final study results. Patients refusing to participate in the study were recorded and evaluated for reasons of refusal. The post-operative pain relief techniques applied in this trial are commonly used, but nevertheless the refusal rate was higher than expected. When it was mentioned that an epidural technique was a part of the trial, 16.7% of the total protocol-eligible group refused. The responses of those offered an epidural could be divided into two groups: the adamant pros and cons to this technique. It can be concluded that in order to be able to judge the validity of results and thus for good clinical practice, the number of patients refusing to participate in a clinical trial and their reasons, should be mentioned in all publications.

To compare the efficacy in the treatment of post-operative nausea and/or vomiting (PONV), 75 patients undergoing gynaecological procedures under general anaesthesia using N2O/enflurane who suffered from PONV in the first hour after surgery were randomly allocated to three groups containing 25 patients each to receive either alizapride 100 mg, droperidol 1mg or ondansetron 8mg (i.v.). Patients expressed the severity of their nausea on a Visual Analogue Scale (VAS) ranging from 0 (none) to 10 (as bad as possible). Vomiting was recorded as present or absent, and the number of emetic events was noted. Data were recorded until rescue medication was given or until 4 h after the administration of the study drug. There were no significant differences between the three groups in the average VAS scores and the presence of vomiting at the time of entry into the study. Fifteen and 30 min after the administration of the study drug, VAS decreased notably in all groups. This decrease was similar and statistically significant within each group. However, comparison between the three groups showed no statistically significant differences. There was no statistically significant difference between the three groups in the number of patients receiving rescue medication, the number of emetic events and the time from administration of the study drug until rescue medication was given. It is concluded that alizapride 100 mg, droperidol 1mg and ondansetron 8mg intravenously are equally effective in the treatment of PONV after gynaecological procedures and that the newer drugs alizapride and ondansetron offer no advantage over droperidol.

Fifty patients were randomly allocated to receive either a preinduction inhalation with nitrous oxide (50%) in oxygen or fentanyl with preoxygenation, before induction of anaesthesia with propofol. Both groups of patients showed a significant rise in arterial oxygen saturation prior to propofol induction which established similar depths of anaesthesia, determined by the acceptability of the laryngeal mask placement. In the fentanyl group there was a significant period of apnoea after induction, with 40% of the patients being apnoeic for 120s or more and requiring assisted ventilation. Reduction in arterial blood pressure was also more rapid in the fentanyl group compared with the nitrous oxide group. Preinduction inhalation of nitrous oxide (50%) in oxygen appears to be an effective and acceptable method of preoxygenating the patient and augmenting the propofol induction of anaesthesia.

Cardiovascular responses after epidural alkalinized lignocaine and subarachnoid hyperbaric bupivacaine administration were studied using a non-invasive cardiac output measurement in 32 ASA Grade I–II patients undergoing orthopaedic leg surgery (hip hemi-arthroplasty or Ender nailing). All patients achieved adequate surgical anaesthesia. The block onset time was faster (P = 0.003), and the range of final sensory level wider (P = 0.006) in patients receiving spinal anaesthesia compared with the epidural group. Diastolic arterial pressure was significantly reduced when compared with base-line (P = 0.002) only in the spinal group. No significant changes in stroke volume, systemic vascular resistance or left ventricular stroke work were observed in either group. Heart rate and cardiac index were significantly reduced in the spinal group when compared both with base-line (P = 0.002; P = 0.04) and the epidural group (P = 0.001; P = 0.006). The results demonstrated that the block onset time and the cardiovascular effects produced by lumbar epidural anaesthesia, with alkalinized solutions, remain less than after spinal anaesthesia involving the same segments.

Two cases of bradycardia following the intra-operative use of ketorolac given intravenously (i.v.) to children are reported. We examine why this may not have been previously reported and make recommendations regarding its use.

The effect in isolated rat aorta of propofol, thiopentone, midazolam, etomidate and fentanyl on the impairment of endothelium-dependent relaxation by reactive oxygen species is reported. Aortic rings were exposed to reactive oxygen species by the electrolysis of the bathing physiological buffer, and endothelium dependent relaxation in response to acetylcholine was inhibited. This inhibition was countered by incubation before electrolysis with propofol (2 × 10−5 and 6 × 10−5M) or thiopentone (10−5 − 10−5M), but not with midazolam (3 × 10−4M), etomidate (3 × 10−4M) or fentanyl (3 × 10−5M). We suggest that the protective effect of propofol and thiopentone against the loss of endothelium-dependent relaxation caused by reactive oxygen species may be because of their antioxidant and free radical scavenging properties, which could be clinically relevant during surgical procedures in which ischaemia is unavoidable.

We have studied the effect of clonidine on gastric motility, by examining the effect on gastric emptying of indigestible solids. In Wistar rats, either clonidine or saline was injected intraperitoneally, and ten steel balls (1.0mm in diameter) were inserted into the stomach. Gastric emptying was examined at 3 h. Clonidine delayed gastric emptying of steel balls (ED50 = 0.0071 [95% confidence interval: 0.0033–0.013) mg kg−1). Yohimbine, but not naloxone, significantly antagonized the inhibitory effect of clonidine. We conclude that clonidine inhibits gastric motility through the alpha2 adrenoceptor.

This study was designed to test the hypothesis that propofol, which possesses antioxidant properties, would produce greater protection than isoflurane incerebral ischaemia reperfusion injury, at dose levels that produced similar effects on brain electrical activity. Twenty Sprague-Dawley rats were anaesthetized using isoflurane 1.5% in air/oxygen, and mechanically ventilated to a PaCO2 of 4.5 kPa. Following 90 min of middle cerebral artery occlusion using an intraluminal filament, rats were given, in random order, either propofol 1mg kg−1 min−1 or isoflurane 3% (both of which have been shown to reliably produce EEG burst suppression). After a further 30 min, reperfusion was induced by withdrawing the filament. Animals were killed following 240 min of reperfusion. Rats in the propofol group showed a 21% reduction in mean hemispheric infarct volume when compared with the isoflurane group (P < 0.0001). These data suggest that propofol may act by mechanisms in addition to CMRO2 depression, and provide a basis for further studies of propofol neuroprotection.

The sensitivity of train-of-four (TOF) or double burst stimulation3,3 (BBS3,3) was examined to detect fade by visual inspection, at varying stimulating currents, using the thumb of the investigated arm maintained abducted by the use of a rubber band. One-hundred adult patients were allocated randomly to (1) train-of-four-rubber band (TOF-RB), (2) train-of-four-control (TOF-control), (3) double burst stimulation-rubber band (DBS-RB), or (4) double burst stimulation-control (DBS-control) group. Each group contained 25 patients. The thumb of the investigated arm was kept abducted using a rubber band in the TOF-RB band and DBS-RB group and was free in the TOF-control and DBS-control. TOF stimuli were delivered in the TOF-RB and TOF-control groups, and DBS3,3 in the TOF-RB and TOF-control at 50, 30 and 20 mA. The probability of visual detection of TOF fade was the same in the TOF-RB and TOF-control groups. In contrast, when measured TOF ratio was 0.51–0.80, at the stimulating current of 50 or 30 mA, the likelihood of visual detection of fade in the DBS-RB group was significantly higher than in the DBS-control group (P < 0.05). With a TOF ratio of 0.61–0.70, in the DBS-RB group the probability of visual detection of fade at 50 or 30 mA was significantly higher than at 20mA (P < 0.05). This study suggests that when using a rubber band, fade in response to the DBS3,3 is detected by visual inspection more readily at a stimulating current of 50 or 30mA than without the rubber band.

Factors affecting flow through blood administration sets in vitro were assessed under gravity-fed and pressurized conditions including an assessment of the influence of the intravenous (i.v.) cannula and Luer lock fitting. The fastest gravity-fed flow of 4.775 mL s−1 was obtained through the largest internal diameter (ID = 4.8mm) blood administration set. Flow through blood administration sets with ID = 3mm was 50% of this. Flow increased over base-line through all the administration sets when the i.v. cannula was removed (range 18–50%) and increased further over base-line when the Luer lock fitting was removed from the distal end (range 26–129%), indicating that these are rate-limiting steps in the system. The Y-type trauma set with the largest diameter tubing facilitated the fastest flow, although flow through all the Y-type trauma sets produced lower flow rates than the corresponding blood administration sets, which may reflect their relative increased length. The ideal blood administration set should have an internal diameter at least 4mm and be less than 170 cm in length.