Sometimes progress is hard to see, when looking at the big picture, because there is very little of it. But sometimes progress is hard to see because the big picture is out of focus. When perioperative deaths ascribed to anaesthesia are in the order of 1 in 20 000 operations and even changes in major morbidity require massive sample sizes to detect, neuroanaesthesia's most emphatic yardstick of progress is too crude to measure advances that have occurred over the most recent decade. We clearly need to become more familiar with neuropsychological tests that can detect subtle changes. Today, for elective neurosurgery, we are primarily in the business of doing two things – pushing the envelope for surgical intervention to include cases that would have been considered too risky 15 years ago, and reducing the frequency of “Uncle-Joe-has-never-been-the-same-since-they-operated-on-his-brain syndrome”. Both of these areas of progress are empirically measurable, but we have not made much progress towards measuring them. Of course, this measurement problem plagues anaesthesiology generally, and we need to attend to it in general. Meanwhile, saying where we are relative to the recent past and the near future involves a lot of guesswork. What follows is my guesswork about progress in neurosurgical anaesthesiology.

The aim of this study was to compare the effect of three different induction techniques, with or without neuromuscular block, on tracheal intubation, haemodynamic responses and cardiac rhythm. Ninety children, aged 1–3 years, undergoing day-case adenoidectomy were randomly allocated to three groups: group TS received thiopentone 5 mg kg−1 and suxamethonium 1.5 mg kg−1, group H 5 Vol.% halothane and group PA alfentanil 10 μg kg−1 and propofol 3 mg kg−1 for induction of anaesthesia. No anticholinergics were used. Holter-monitoring of the heart rate and rhythm was started at least 15 min before induction of anaesthesia and continued until 3 min after intubation. Tracheal intubation was performed by an anaesthetist blinded to the induction method and judged as excellent, moderate or poor according to ease of laryngoscopy, position of vocal cords and incidence of coughing after intubation. Tracheal intubation was successful at the first attempt in all children in groups TS and H and but only in 80% in group PA (P=0.001). Intubating conditions were excellent in 22 (73%), 22 (73%) and one (3%) of the patients in groups TS, H and PA, respectively (P=0.001). Cardiac dysrhythmias (supraventricular extrasystole or junctional rhythm) occurred in two (7%) patients in groups PA and H each (NS). Bradycardia occurred in 0 (0%), four (14%) and six (21%) children in groups TS, H and PA, respectively (P=0.007 PA vs.TS, P=0.03 H vs. TS). In conclusion, induction of anaesthesia with propofol 3 mg kg−1 and alfentanil 10 μg kg−1 without neuromuscular block did not provide acceptable intubating conditions in children 1–3 years, although it preserved arterial pressure better than thiopentone/suxamethonium or halothane. Cardiac dysrhythmias were few regardless of the induction method.

The effects of bolus and infusion doses of propofol on histopathological changes in the rat pancreas are reported. After obtaining Hospital Ethics Committee approval, 75 female Wistar rats were assigned to three study groups. Groups I (n=30) and II (n=30) received 10 mg kg−1 intravenous bolus of propofol; with propofol administered to group II at an infusion rate of 10 mg kg−1 h−1 for 30 min immediately after the bolus doses. Group III (n=15) was used as the control group. Twenty-four hours after propofol administration blood samples and pancreatic tissue specimens were obtained under ether anaesthesia. Plasma cholesterol, triglyceride, amylase, and lipase levels were studied, and pancreatic tissues were examined under light microscopy. Plasma cholesterol and triglyceride levels were significantly higher in group II compared with the other groups. Differences between the groups in respect of plasma amylase and lipase levels were not statistically significant. Acute pancreatitis was observed under light microscopy, in three rats (10%) in group II, and in one rat (6.6%) in the control group. The pancreatic tissues of group I were normal. The incidence of acute pancreatitis in each of the groups was not significant. It is therefore suggested that, further controlled studies are needed to investigate the relation between pancreatitis and the use of propofol.

The cuffed oropharyngeal airway (COPA) was compared with the laryngeal mask airway (LMA) with respect to airway quality and respiratory adverse events in 140 spontaneously breathing patients undergoing procedures of duration more than 1 h. Patients were allocated randomly to receive either a COPA (n=72) or a LMA (n=68) for airway management during anaesthesia induced with propofol and maintained with sevoflurane, nitrous oxide and oxygen. Groups were similar when comparing the first-time successful insertion rates (COPA: 94.5%, LMA: 95.6%), but airway manipulations (head tilt, chin lift, jaw thrust) were reported more frequently in the COPA group, 27.8% vs. LMA, 4.4%; P=0.0005. During the post-induction apnoeic period, all patients were ventilated manually and although, mean (SD) leak pressure was lower in the COPA group (18 (4) cm H2O vs. LMA, 22 (3) cm H2O; P< 0.0001), the tidal volumes achieved did not differ in both groups: COPA, 9.5 (4) mL kg−1 vs. LMA, 10.5 (4.5) mL kg−1. The incidences of intra-operative coughing, gagging, laryngospasm, oxygen desaturation and hypercarbia were similar in both groups. Although both devices are equivalent with respect to the overall respiratory problems during spontaneous breathing anaesthesia of intermediate or prolonged duration, the LMA was associated with fewer airway quality problems, suggesting that it is more efficacious in securing the airway.

This study was undertaken to compare the efficacy and safety of granisetron, a 5-hydroxytryptamine type 3 receptor antagonist, and dexamethasone and each drug alone for the prevention of post-operative vomiting by children, with no history of motion sickness and/or previous post-operative vomiting, undergoing general inhalational anaesthesia for surgery (inguinal hernia and phimosis). In a randomized, double-blind manner, 150 children, ASA physical status I, aged 4–10 years, were assigned to receive granisetron 40 mg kg−1, dexamethasone 150 mg kg−1, or granisetron 40 mg kg−1 plus dexamethasone 150 mg kg−1 intravenously immediately after inhalation induction of anaesthesia (n=50 of each). A complete response, defined as no emesis and no need for another rescue anti-emetic during the first 24 h after anaesthesia, was 86% with granisetron, 68% with dexamethasone and 98% with granisetron plus dexamethasone, respectively (P< 0.05; overall Fisher's exact probability test). No clinically serious adverse events were observed in any of the groups. In conclusion, prophylactic therapy with combined granisetron and dexamethasone was more effective than was each anti-emetic alone for the prevention of vomiting after paediatric surgery.

The acute influence of therapeutic doses of theophylline on cerebral blood flow velocities during general anaesthesia induced either by halothane or isoflurane has not been elucidated previously. The aim of this study, was therefore to investigate these effects during steady state anaesthetic conditions in anaesthetized patients using transcranial Doppler sonography. Thirty-four Patients were investigated. Anaesthesia was maintained either with 1 MAC (minimum alveolar concentration) halothane (n=16) or 1 MAC isoflurane (n=18); FiO2: 40%; end-expiratory pCO2: normocapnia. Theophylline administration was performed before surgery by infusing 6 mg kg−1 over a period of 7.5 min. Measurements were recorded prior to theophylline administration, and immediately after 2 mg kg−1 (2.5 min), 4 mg kg−1 (5 min) and 6 mg kg−1 (7.5 min), as well as 5, 10, 15, 20, 30 and 45 min after theophylline administration. Recorded variables included blood pressure, heart rate, arterial oxygen saturation, end-expiratory pCO2, body temperatures, middle cerebral artery blood flow velocity and pulsatility index. Theophylline administration was well tolerated by all study subjects. Heart rate, blood pressure, body temperatures, arterial oxygen saturation and end-expiratory pCO2 remained constant during the whole examination period. Following theophylline, mean blood flow velocity decreased by 25% in the halothane and by 30% in the isoflurane group (P< 0.05). By the end of the examination period, mean blood flow velocity had not yet recovered to the initial values whereby in both groups the mean blood flow velocity was 26% below the initial values. In the isoflurane group, the pulsatility index increased by about 20% (P< 0.05) and remained high until the end of the examination. In the halothane group, however, there were no changes in the pulsatility index. Our results show a remarkable, significant and simultaneous decrease in blood flow velocity in the middle cerebral artery associated with theophylline administration during halothane and isoflurane anaesthesia in man.

After an intubating dose of rocuronium satisfactory intubating conditions are achieved before the onset time at the adductor pollicis. We examined the possibility that measurement of the relaxation of the masseter muscle is a more appropriate guide when determining the intubating time. Simultaneous accelerometry with a 0.1-Hz single twitch stimulation of the chin and thumb was performed in 20 patients after 0.6 mg kg=1 rocuronium. We observed a significantly more brief mean lag time and onset time at the masseter muscle (22.5 and 61 vs. 32.5 and 160 s). The corresponding mean relaxation at the onset time was also significantly more pronounced at the masseter muscle (99.6 vs. 97.6%). A mean onset time at the masseter muscle of 61 s as produced by rocuronium corresponds clinically with excellent or good intubating conditions. From these results, we suggest that measurement of the onset time of muscle relaxation at the masseter muscle appears to be a better predictor of good intubating conditions than measurements made using the adductor pollicis muscle after administration of rocuronium.

The anti-emetic efficacy of prophylactic ondansetron and tropisetron in combination with a low dose of droperidol in patients with high probability for post-operative nausea and vomiting undergoing gynaecological laparoscopy was compared. Patients were randomly allocated in a double-blind manner to receive either ondansetron 8 mg (n=45) or tropisetron 5 mg (n=43) at the end of surgery. A standardized general anaesthetic technique was used, including droperidol 0.75 mg. The incidence of nausea was 36% and 49% (P=0.28), and vomiting occurred in 13% and 14% of the patients in the ondansetron and tropisetron groups, respectively. The onset time for rescue medication was significantly sooner after tropisetron than ondansetron (3 h 18min vs. 6 h 25min; P=0.007). There were no statistically significant differences in efficacy between prophylactic ondansetron and tropisetron combined with droperidol in a high-risk population. However, ondansetron appeared to be more effective in preventing post-operative nausea and vomiting in the early hours after surgery compared with tropisetron.

Intrinsic positive end-expiratory pressure can occur when the sternum is closed following cardiac surgery, causing anaesthetic and surgical problems. We measured intrinsic positive end-expiratory pressure after sternal closure in two studies of patients undergoing coronary artery bypass grafting with the same anaesthetic regime. In one, patients were ventilated at 10 breaths min−1, in the other they were randomized to be ventilated at 10 or 20 breaths min=1. After sternal closure, intrinsic positive end-expiratory pressure increased significantly, especially in patients in whom it had been present before sternotomy. Multiple linear regressions with the pooled data from the studies showed that intrinsic positive end-expiratory pressure was positively correlated with ventilatory rate (P<0.005), age (P<0.005) and Body Mass Index (P<0.0005), and negatively with FEV1, as percentage of predicted (P<0.01). There was no correlation between intrinsic positive end-expiratory pressure and a history of smoking. As there was no difference in expiratory resistance between patients ventilated at the two different rates, any effect on intrinsic positive end-expiratory pressure of the higher ventilatory rates could have been due only to the shorter expiratory time.

The post-operative period is particularly dangerous for obese patients. The aim of this study was to compare the immediate post-operative course after either laparoscopic or open gastroplasty. We studied retrospectively 20 and 14 consecutive patients who underwent laparoscopic or open adjustable silicone gastric banding, respectively. After the laparoscopic procedure, patients had a significantly shorter stay in the post-anaesthesia care unit (0.3±0.4 and 1.1±1 days), reduced analgesic requirements, a shorter period of intravenous catheter use (2.3±1.9 and 4.8±1.4 days), were able to walk sooner (1±0.4 and 2.1±1.6 days) and had a significantly shorter duration of in-hospital stay (5.4±2.3 and 15.8±4.5 days) than after an open procedure. This report suggests that the use of laparoscopy for gastroplasty in morbidly obese patients may significantly improve the immediate post-operative course.

Trauma is often assumed to increase the risk of pulmonary aspiration of gastric contents. The 247 anaesthetists in the Trent region of England were surveyed by postal questionnaire to ascertain the current practice for identifying patients at risk of pulmonary aspiration of gastric contents following trauma. The response rate was 79%. The anaesthetists rated the reliability of several criteria when predicting ‘gastric safety’ and stated whether each criterion formed part of their clinical practice. Interval of eating to injury was the most used (88%) and highest rated criterion (4/5) followed by use of opioids. Presence or absence of bowel sounds was the least used (7%) and lowest rated criterion (0/5). Currently there is little evidence that the commonly used criteria accurately identify ‘at-risk’ patients. There is little evidence that trauma increases the risk of aspiration although a number of factors associated with trauma are known to delay gastric emptying.

We present a case of accidental epidural administration of potassium chloride, which was diagnosed by clinical signs. The genesis of symptoms and signs following such administration is discussed and compared with other published reports.

Iatrogenic pneumocephalus is an uncommon complication observed after using the ‘loss-of-resistance’ technique with an air filled syringe. We report and review two cases of pneumocephalus: one subarachnoid and the other epidural.