The value of pulmonary artery catheterization is a matter for discussion. Previous studies suggest that direct measurements of intravascular volume distribution and cardiac volume indices may be of greater relevance than central venous and pulmonary capillary wedge pressure. We therefore used a thermo-dye dilution technique for the quantification of central blood volume, right ventricular end-diastolic volume and left heart volume in patients undergoing coronary artery bypass surgery. Measurements were performed after the induction of anaesthesia as well as 1, 6 and 24 h after surgery. Central venous pressure was significantly increased at 1 and 6 h, whereas right ventricular end-diastolic volume was increased only at 6 h post-operatively. Pulmonary capillary wedge pressure showed a tendency to increase whereas left heart and central blood volume decreased significantly after surgery. The results of the present study suggest that changes in cardiac filling pressure do not indicate changes in indices of cardiac volume in patients after coronary bypass surgery.

Optimal control of long-term sedation during therapy in the intensive care unit is difficult to achieve in a number of patients when based on commonly used clinical sedation scores alone. We therefore used the median frequency of the EEG power spectrum as a quantitative measure for closed-loop administration of propofol in 21 artificially ventilated patients (nine trauma, 12 non-trauma). The EEG setpoint was correlated with a clinical sedation score and defined such, that mechanical ventilation was tolerated. The sedative therapy was given for 31±30 h. Non-trauma patients required sedation with an EEG median frequency between 2 and 3 Hz (propofol consumption: 1.4±0.8 mg kg−1 H−1) and sedation seemed to follow some circadian patterns, whereas trauma patients needed significantly deeper sedation (EEG median frequency: 1–2 Hz; propofol consumption: 2.6±0.8 mg kg−1 h−1). We conclude that the EEG closed-loop system could safely and reliably administer propofol to maintain a predetermined level of sedation for patients in intensive care unit over a protracted time.

The present study was undertaken to evaluate the impact of a new procedure for eliciting informed consent by patients undergoing minor surgical procedures, in which the choice between general anaesthesia (GA) and regional anaesthesia (RA) was possible. In this prospective study, two randomly selected groups of patients were compared: study group (SG), 52 patients, received from the nurse before the preoperative interview, a list of seven questions, which they were invited to ask the anaesthetist; while the control group (CG), 73 patients, did not receive any suggested questions. There were two end points: the proportion that chose RA and the number of questions actually addressed to the doctor at the preanaesthetic interview. Psychological aspects were taken into account by collecting the Hospital Anxiety and Depression (HAD) scale before the preanaesthetic interview. Satisfaction with the interview was recorded using a telephone questionnaire 2 weeks after the operation. The results from the two groups were compared by calculating the odds ratio according to Mantel–Haenszel and by logistic analysis. Altogether, 71.2% of the patients chose RA without any difference between the groups. The average number of questions asked by each SG patient was higher than for the CG (1.67 vs. 0.96). The satisfaction level was similar in the two groups. Our list of questions was designed to facilitate patient autonomy. It offered an aid to those requesting more information and assisted communication. The method did not change the proportion who chose a specific kind of anaesthesia, but does seem to improve patient participation in the decision-making process.

Both continuous spinal anaesthesia and continuous epidural anaesthesia are supposed to provide adequate post-operative pain relief. The purpose of this randomized, prospective study was to compare the quality of analgesia, occurence of side effects and patient satisfaction between spinal and epidural administration of bupivacaine during the first post-operative 72 h. One hundred and two patients scheduled for hip arthroplasty were randomly assigned to one of two groups: Group 1 received continuous spinal anaesthesia for intra-operative and post-operative management, Group 2 received continuous epidural anaesthesia. Immediately after surgery, the continuous spinal anaesthesia-group received a 1-mL bolus (bupivacaine 0.25%), followed by a continuous infusion of 10 mL over 24 h. The continuous epidural anaesthesia-group received a 10-mL bolus (bupivacaine 0.25%), followed by 2mL h−1. The level of pain was gauged from a verbal rating score and from a visual analogue scale; the degree of motor blockade was recorded using the Bromage score. In the continuous spinal anaesthesia-group 90.2% reported complete analgesia on the verbal rating scale, but only 21.6% of the continous epidural anaesthesia-group did. The visual analogue scale scores given by the continuous spinal anaesthesia-group were significantly lower than those of the continuous epidural anaesthesia-group. The percentage of patients with a motor block was significantly higher in the continuous spinal anaesthesia-group on the day of surgery and at the first post-operative day. During the first 24 h,nausea and vomiting occured more often in the continuous epidural anaesthesia-group. The satisfaction was considered excellent in 92.2% of the continuous spinal anaesthesia-group and in 70.6% of the continuous epidural anaesthesia-group. It is concluded that continuous spinal anaesthesia and continuous epidural anaesthesia are effective and safe for post-operative pain relief after hip replacement. Compared with continuous epidural anaesthesia, continuous spinal anaesthesia provides faster onset of pain relief,ensures better analgesia and results in more satisfied patients.

Tramadol, a weak opioid μ-receptor agonist, may have a favourable potency and side effect profile for intravenous patient-controlled analgesia (PCA). In a prospective, double-blind, randomized study involving 54 patients, tramadol was compared with oxycodone in PCA after maxillofacial surgery. All the patients were given diclofenac sodium 1 mg kg−1 intramuscularly and dexamethasone 8 mg twice a day. Post-operatively patients received tramadol or oxycodone by a PCA apparatus (lockout 5 min, tramadol 0.3 mg kg−1 bolus, oxycodone 0.03 mg kg−1 bolus). During the immediate recovery period, opioid was administered i.v. in a double-blind fashion, either tramadol 10 mg or oxycodone 1 mg increments until the pain control was judged to be satisfactory by the patient. Pain was assessed at rest and during activity (mouth opening) before and after loading, at 2 h after commencing the PCA, as well as at 21.00 and at 09.00 hours on the following morning. Side effects were recorded. The potency ratio of tramadol to oxycodone was found to be approximately 8:1. There was no significant difference between the groups in the VAS scores for pain. No respiratory depression was identified. Tramadol was found to provide adequate analgesia after maxillofacial surgery without risk of respiratory depression. However, the incidence of nausea was slightly greater in the tramadol group than in the oxycodone group (44% vs. 28%, NS).

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.

The dose-related effects of milrinone, a phosphodiesterase (PDE) III inhibitor, on the contractility of fatigued diaphragm were studied in dogs. Animals were divided into three groups of eight each. Diaphragmatic fatigue was induced by intermittent supramaximal bilateral electrophrenic stimulation at a frequency of 20 Hz applied for 30 min. After the production of fatigue, Group I received no study drug; Group II was infused with milrinone (50 mg kg−1 loading dose plus 0.2 mg kg−1 min−1 maintenance dose); Group III was infused with milrinone (50 mg kg−1 loading dose plus 0.5 mg kg−1 min−1 maintenance dose). Diaphragmatic contractility was assessed by measurement of transdiaphragmatic pressure. After the fatigue-producing period, transdiaphragmatic pressure at low-frequency stimulation (20-Hz) decreased from the prefatigued values in all groups (P < 0.05), whereas transdiaphragmatic pressure at high-frequency (100-Hz) stimulation did not change. Compared with Group I, transdiaphragmatic pressure to each stimulus increased during milrinone infusion in Groups II and III (P < 0.05). The increase in transdiaphragmatic pressure was greater in Group III than in Group II (P < 0.05). It is concluded that milrinone is associated with a dose-related effect on the contractility of fatigued diaphragm in dogs.

Dimenhydrinate is an inexpensive antihistaminic drug, that is frequently used as an anti-emetic during anaesthesia. The popularity of the drug is contrasted by the lack of modern studies concerning its efficacy in reducing the incidence of post-operative nausea and vomiting. Thus, dimenhydrinate was compared with placebo in this prospective, randomized, double-blind study. One hundred and thirty-three female in-patients were studied. They were stratified according to the type of surgery (laparoscopic cholecystectomy, thyroid resection or knee arthroscopy) to ensure an homogenous distribution in both groups. General anaesthesia was induced with etomidate, fentanyl, vecuronium and maintained with enflurane in N2O/O2. Neuromuscular block was reversed with pyridostigmine/atropine. Patients in the dimenhydrinate group (n=67) received 62 mg dimenhydrinate intravenously after induction of anaesthesia. Placebo patients (n=66) received saline. Administration of dimenhydrinate (and placebo) was repeated three times during the 48-h study to mitigate the short half-life of the drug. Post-operative analgesia and anti-emetic rescue medication was standardized. Episodes of vomiting, retching and the need for additional anti-emetics were recorded. Nausea was assessed using a 10-cm visual analogue scale. Post-operative nausea and vomiting was rated as ‘none’, ‘mild’, ‘moderate’ and ‘severe’ using a fixed scoring algorithm. There were no differences between the two groups with regard to biometric data, type of surgery and distribution of risk factors for developing post-operative nausea and vomiting. In the dimenhydrinate group, more patients remained completely free from post-operative nausea and vomiting compared with placebo (dimenhydrinate: 38.8%; placebo:15.1%; P=0.004). The incidence of severe post-operative nausea and vomiting was also reduced from 39.4% to 14.9%. No relevant side effects were observed. Intra-operative dimenhydrinate, followed by three further administrations after surgery, reduces the incidence and the severity of post-operative nausea and vomiting without side effects. However, there still remained an unacceptable high number of patients who were not prevented completely from experiencing post-operative nausea and vomiting.

The study compares responders and non-responders to post-operative patient-controlled analgesia (PCA) and evaluates factors that might differ between these two groups in order to identify non-responders during the early post-operative period. A prospective, randomized, double-blinded study design was used. Patients recovering from abdominal surgery were assigned to one of three treatment groups for a study period of 48 h. After titration of an individual loading dose, patients could self-administer 1 mL bolus doses(2 mg of morphine, 20 mg of tramadol or placebo) using a PCA device. Patients responding or not responding to the treatment were identified. In non-responders the escape medication was morphine.There were 96 responders and 65 non-responders. All responders showed similar pain scores, irrespective of the drug they received. Drug consumption of placebo responders was twice as high as that of opioid responders. Pain scores and analgesic consumption of non-responders were significantly higher compared with responders, although those patients received morphine. The loading dose correlated with subsequent analgesic consumption. Altogether, 89.2% of the non-responders were identified after the loading dose. Size of loading dose and pain scores during the first 30 min are useful for assessing the overall response to post-operative pain management. These factors may be valuable for predicting individual pain management.

Changes in heart rate, systolic, diastolic and mean blood pressure were measured after extubation in 60 ASA Grade I and II patients to assess the effects of diltiazem (0.2 mg kg−1), verapamil (0.05 mg kg−1) and metoprolol (0.02 mg kg−1) given as a bolus 2 min before tracheal extubation. All the haemodynamic variables measured increased significantly after extubation in the control and diltiazem groups when compared with the base-line recordings (P<0.05). Metoprolol effectively blocked the increases in heart rate after extubation and the increase in blood pressure in this group was less when compared with the control group (P<0.05). Verapamil alleviated the increase in both heart rate and blood pressure. However, profound hypotension and bradycardia requiring therapy, occurred in the verapamil group. For this reason, careful observation is necessary when using variverapamil and the routine use of this drug in patients with coronary artery disease requires further studies.

We investigated the effects of controlled hypotension with haemodilution under isoflurane anaesthesia on splanchnic perfusion in elderly patients. We determined the intramucosal pH using gastric tonometry in 28 patients scheduled for hip surgery. Patients without cardiac disease were assigned to two groups according to age. Group A (adult patients, n=14) included patients aged less than 60 years (range 29–58 years, 47±11 years, mean±SD) and group B(elderly patients, n=14) more than 65 years (68–78 years, 72±5 years). Anaesthesia was maintained with N2O-O2-isoflurane. After induction of anaesthesia, haemodilution was produced by drawing 800–1000 mL of blood and replacing it with the same amount of hydroxyethyl starch. Final haematocrit values were 23–24% in all groups. Controlled hypotension was induced with prostaglandin E1 (PGE1) and mean blood pressure was maintained at approximately 60 mmHg for approximately 80 min. Measurements, including gastric intramucosal pH (pHi), arterial blood pH (pHa) and serum lactate were measured before haemodilution (T0), after haemodilution (T1), 80 min after starting hypotension (T2), 60 min after recovery from hypotension (T3) and on the 1st post-operative day (T4). The values of pHa and lactate showed no change in the groups throughout the time course. The gastric pHi values showed significant decreases from 7.418±0.035 to 7.334±0.024 (P < 0.05) in group A and from 7.428±0.029 to 7.320±0.039 (P < 0.05) in group B after haemodilution, while no further decreases were found at 80 min after starting the hypotension (7.329±0.038 in group A and 7.322±0.031 in group B) and 60 min after recovery from hypotension (7.331±0.029 in group A and 7.328±0.034 in group B). It can be concluded that moderate haemodilution under isoflurane anaesthesia might impair splanchnic perfusion in adult and elderly patients. The addition of controlled hypotension with PGE1 or an increase in age did not further impair splanchnic perfusion nor the splanchnic oxygen supply.

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.

This double-blind, randomized trial compared the onset of sedation with two patient-controlled sedation regimens, allowing a maximum of 16 or 25 mg min−1 propofol. Forty fit young patients presenting for elective surgery were asked to try to put themselves to sleep using the system. Onset times of sedative effect, slurred speech and amnesia were recorded. All patients achieved satisfactory sedation, and none became oversedated. Patients receiving 16 mg min−1 propofol were not reliably sedated within 5 min and took significantly longer to develop slurred speech and amnesia (P< 0.01 for both). We conclude that this maximum infusion rate does not produce amnesia or sedation rapidly enough to be clinically useful. A maximum infusion rate of 25 mg min−1 allowed rapid sedation in all patients without oversedation and may be an acceptable compromise between efficacy and safety.

All consultants and trainees in anaesthesia in a large teaching hospital were surveyed. Details of the number of flights per year and details of any medical emergencies in which they had been involved were recorded. The mean number of flights per year was 7.1 domestic and 3.4 international. Of the 45 anaesthetists surveyed, 14 had dealt with emergencies in flight, four had dealt with more than one. The minor emergencies (12) included transient ischaemic attacks, abdominal pain and otitis media. The seven serious events included seizures, angina, hypoglycaemic coma, respiratory arrest and two fatal cardiac arrests. No flights were diverted. On only two occasions were their medical qualifications checked. Requests for documentation were unusual. On several occasions the equipment which was available was inadequate. All doctors that responded were insured in the UK and most stated that they would assist Americans on American airlines. Medical emergencies were more likely on long haul flights.

Post-operative nausea and vomiting is distressing for patients and can cause dissatisfaction and impaired well-being in the post-operative period. This study examined the question whether the reduced incidence of post-operative nausea and vomiting inevitably translates into improved clinical status and well-being. In this context high doses of droperidol were investigated. On the one hand, droperidol is known to be a powerful anti-emetic, but on the other hand there is concern about psychological effects, both in the pre- and the post-operative period. In this prospective randomized double-blinded study, droperidol (5–7.5 mg) was compared with midazolam (5–7.5 mg) used to supplement fentanyl-N2</O based anaesthesia, with respect to post-operative mood and well-being using a psychological questionnaire (Bf-S-test). Furthermore, the incidence of post-operative nausea and vomiting was recorded. Out of 160 patients undergoing thyroidectomy and laparoscopic cholecystectomy, data from 150 patients were analysed. The administration of droperidol significantly lowered the incidence of post-operative nausea and vomiting from 77.8% to 55.1% compared with midazolam (P=0.0059; χ2-test). Although post-operative nausea and vomiting is an independent risk factor for post-operative discomfort and bad mood, patients receiving droperidol showed impaired well-being 6 h after surgery. Well-being scores returned to pre-operative base-line values and did not differ between the two groups 24 and 48 h post-operatively. The reduced incidence of post-operative nausea and vomiting achieved with high dose droperidol does not equate with increased post-operative well-being. It is an important point at issue to decide whether smaller doses of droperidol that are commonly used for anti-emetic therapy are free of these side effects.

We have compared the efficacy and safety of combined granisetron and droperidol with each anti-emetic alone for preventing post-operative nausea and vomiting after thyroidectomy. In a prospective, randomized, double-blind study, 180 women received granisetron 40 μg kg−1, droperidol 20 μg kg−1, or granisetron 40 μg kg−1 plus droperidol 20 μg kg−1 (n=60 of each) intravenously immediately before induction of anaesthesia. A standard general anaesthetic technique and post-operative analgesia were used. A complete response, defined as no post-operative nausea and vomiting and no need for another rescue anti-emetic, during the first 24 h after anaesthesia occurred in 88%, 60% and 98% of patients who had received granisetron, droperidol and granisetron plus droperidol (P< 0.05; overall Fisher's exact probability test). No clinically important adverse events due to the drugs were observed in any of the groups. In summary, prophylactic use of combined granisetron and droperidol is more effective than each drug alone for the prevention of post-operative nausea and vomiting in female patients undergoing thyroidectomy.

To evaluate the quality of intra-operative anaesthesia and recovery characteristics of two different anaesthesia regimens, 60 healthy women undergoing ultrasound guided oocyte retrieval for in vitro fertilization procedures were randomly allocated to receive either a propofol/fentanyl or a midazolam/remifentanil based anaesthesia. The surgical procedure was successful in all patients and no severe side effects were reported by any patient. Four patients in the midazolam/remifentanil group (13%) would not accept the same anaesthetic procedure for further in vitro fertilization treatment due to intra-operative awareness, while all propofol/fentanyl patients were prepared to accept the same procedure again (P < 0.05). Patients in the propofol/fentanyl group required manual ventilation more frequently through a facemask than those patients treated with the midazolam/remifentanil combination (50% and 30%, respectively; P < 0.05). The time to achieve an Aldrete's score of 10 was shorter in the midazolam/remifentanil patients (2±2 min) than in those who received propofol/fentanyl (4±2 min) (P < 0.001), but no differences were observed in the time required to be ‘fit to discharge’ from the post-anaesthesia care unit. We conclude that the use of a midazolam/remifentanil regimen is as effective and safe as a fentanyl/propofol regimen in patients undergoing transvaginal oocyte retrieval for in vitro fertilization procedures.

Controversy persists over the efficacy of intercostal nerve block administered through a tunnelled extrapleural catheter. We have undertaken a randomized, prospective double-blind trial of two different local anaesthetic regimes to evaluate the effect of this technique on post-thoracotomy pain relief and pulmonary function. Sixty-eight patients were randomized to receive bupivacaine 0.25% (n=22), lignocaine 1% (n=21) or 0.9% NaCl (saline) (n=20) via an extrapleural catheter, inserted peroperatively. All patients underwent a standard posterolateral thoracotomy. Pain was assessed using a visual analogue pain score and by the requirement for opiate analgesia. Pulmonary function was measured using bedside spirometry. Pain scores were lower in the local anaesthetic groups at 24, 32 and 72 h compared with placebo (P< 0.05) and the total amount of opiate required was less than placebo for both lignocaine and bupivicaine (P< 0.05). Pulmonary function was better in the local anaesthetic groups throughout the post-operative period and was most pronounced at 24 h with a mean improvement of 30% for forced expiratory volume (FEV1), 24% for forced vital capacity (FVC) and 19% for peak expiratory flow rate (PEFR) compared with placebo. There was no significant difference between pain scores, opiate requirement or pulmonary function between lignocaine and bupivicaine. CT scanning demonstrated containment of the local anaesthetic in an extra-pleural tunnel. Extra-pleural infusion of local anaesthetics is a simple technique, with low risk of complications and provides effective pain relief as well as an improvement in post-operative pulmonary function. Lignocaine is equally as effective as bupivacaine and its use would result in some cost-saving.

The reduction in propofol-induced pain on injection caused by the addition of lignocaine results mainly from a drop in pH, which reduces the concentration of propofol in the aqueous phase of the emulsion. It is not an effect of the local anaesthetic per se. Propofol emulsion mixed with lignocaine destabilizes within hours. We mixed 10 parts of propofol 1% emulsion with one part of 0.0064 m HCl or 0.013 m HCl, respectively. These mixtures were stored for 3 months and compared with a freshly prepared solution of propofol 1% emulsion and saline, in the same proportion, regarding their ability to induce anaesthesia in the rat. There was no significant difference in the amount of propofol required to induce anaesthesia, nor was there any difference in recovery time between the three groups.

The treatment of tracheo-bronchial diseases with rigid bronchoscopy requires general anaesthesia without tracheal intubation. Spontaneous assisted ventilation is a safe modality of ventilation. In this study the use of remifentanil and fentanyl is compared during rigid bronchoscopy with spontaneous assisted ventilation. Ninety high-risk patients received fentanyl or remifentanil with propofol for general anaesthesia. During the maintenance fentanyl was delivered at 6.1±4.6 μg kg−1 h−1 and remifentanil at 0.15±0.07 μg kg−1min−1. The same degree of intra-operative respiratory acidosis with similar good operating conditions resulted in both groups. Patients treated with remifentanil recovered more quickly compared with those in the fentanyl group (3.8±2 vs. 10.4±9.2 min, P<0.001). In conclusion, the use of remifentanil during rigid bronchoscopy under general anaesthesia with spontaneous assisted ventilation is safe and assures good operating conditions. Moreover, remifentanil permits a more rapid recovery than fentanyl. The dose of remifentanil is higher than previously described for spontaneously breathing patients.