Summary

Background and objective: Although electrocardiography (ECG) guidance of central venous catheters (CVCs) is traditionally thought to detect the entrance into the right atrium (RA), there is little evidence in the literature to confirm this. We previously observed a high incidence of left-sided CVCs abutting the wall of the superior vena cava (SVC), even when the catheters were advanced past the point of increased P-wave amplitude. Our hypothesis was that this ECG amplitude signal is actually detecting the pericardial reflection rather than the RA. The goal of the study was to position catheter tips under ECG guidance outside the RA.

Methods: One-hundred central venous triple-lumen catheters inserted either via the right or the left internal jugular veins, respectively, were analysed in cardiac surgical patients. The position of the catheter tip was ascertained by ECG. Method A: A Seldinger guide-wire in the distal lumen served as exploring electrode, the respective insertion depth was recorded. Method B: The middle lumen (port opening 2.5 cm from the catheter tip, thus the catheter was advanced more towards the atrium) filled with a saline 10% fluid column served as the exploring electrode, and the insertion depth was recorded again. Descriptive data are given as mean ± standard deviation.

Results: On average, the catheters were advanced by the expected 2 ± 0.3 cm using Method B beyond the initial insertion by Method A. All 100 CVCs were finally correctly positioned in the SVC and confirmed by transoesophageal echocardiography. When chest radiography was performed after surgery not a single catheter abutted the lateral wall of the SVC.

Conclusion: Since both methods detected the same structure, and catheters placed by Method B did not result in intra-atrial CVC tip position, the first increase in P-wave amplitude does correspond to a structure in the SVC, most likely the pericardial reflection.

Background and objective: We reviewed retrospectively the anaesthetic management and perioperative course of eight right hepatectomies for living liver donation.

Methods: After preoperative psychiatric evaluation, eight ASA I–II individuals donated the right lobe of their liver to a family member. A graft-recipient body weight ratio of 0.8–1.0% was required for patient selection. Indications for liver transplantation were: hepatitis C viral-related cirrhosis in six patients; combined hepatitis C and B viral cirrhosis in one patient; multifocal hepatocellular carcinoma – four lesions, involving both liver lobes – of hepatitis C viral-related cirrhosis in another patient. Indication for adult-to-adult living-donor liver transplantation was retained in the latter because of rapid deterioration of liver disease, rare recipient's blood group and extended, unresectable hepatocellular carcinoma. Hepatitis C viral-related cirrhosis was casually the primary indication for adult-to-adult living-donor liver transplantation in this group. The condition of the donated hepatic lobe was optimized by appropriate drug and perfusion management. Preoperative investigations included: blood tests (full cell count and film, thyroid function tests, pregnancy tests, full virological tests and bacteriological cultures, and immunological typing), chest radiograph, electrocardiogram plus Doppler cardiac ultrasound, spirometry, aminopyrine breath test, liver Doppler examination, magnetic resonance imaging, angiography and cholangiography and a volumetric study of the whole liver and the right lobe. Haemoglobin and lactate concentrations, liver function tests and international normalized ratio were measured before and after operation. The volume and weight of the resected right lobe was calculated. Anaesthesia was induced with propofol 300 mL h−1 and sufentanil 0.3 μg kg−1 intravenously; cisatracurium, 0.15 mg kg−1, was given to facilitate tracheal intubation. Anaesthesia was maintained during normocapnic ventilation of the lungs with oxygen 40% in air, isoflurane 1–1.5 MAC and sufentanil. Routine anaesthetic monitoring included electrocardiography, pulse oximetry, invasive blood pressure, central venous pressure, urine output, state of neuromuscular blockade and core temperature. Periods of hypotension (< 80% of the preoperative blood pressure) or haemodynamic instability (requiring inotropic or vasoactive support) were registered. Total blood loss and transfusion (homologous, autologous or cell-saver blood) requirements were measured; volume replacements were derived.

Results: Data are presented as mean (range). There was no morbidity or mortality and no periods of intraoperative hypotension or haemodynamic instability. The operation time averaged 619 (525–780) min. Four donors were extubated in the operating room immediately after surgery; the others were extubated in the intensive care unit, where the mean extubation time was 16.3 (5–25) h after arrival. The estimated blood loss was 967 (550–1600) mL. No homologous blood was administered; five donors received autologous blood,intraoperatively; three donors received a cell-saver blood transfusion. Intraoperative fluid replacement was with crystalloids, colloids and 4% albumin. Total urine output was 1472 (700–3100)mL. Although intraoperative hypothermia occurred all subjects were normothermic at the end of operation. The pre- and immediately postoperative haemoglobin concentration averaged 13.6 (9.8–15.6) and 10.5 (6.9–13.0) g dL−1 respectively. On the first postoperative day, the haemoglobin was 11.7 (8.4–15.1) g dL−1. The donors' liver function tests were transiently elevated in the initial postoperative period. The intensive care unit discharge time was 2 (1–3) days. The hospital stay was 13 (7–17) days. There was no morbidity or mortality.

Conclusions: The study demonstrates that right-lobe living-donor surgery was well tolerated, without intraoperative hypotension or haemodynamic instability, without perioperative anaesthetic or surgical complications, and with an excellent general outcome.

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.

Summary

Background and objective: Since the introduction of the laryngeal mask into clinical practice, various additional supraglottic ventilatory devices have been developed. Although it has been demonstrated that the laryngeal tube is an effective airway device during positive pressure ventilation no clinical study has been performed thus far regarding its use in patients with predicted ventilation and intubation difficulties. Methods: The aim of this study was to prospectively evaluate the use of the laryngeal tube for temporary oxygenation and ventilation in adult patients with supraglottic airway tumours scheduled to undergo a pharyngeal–laryngeal oesophagoscopy and bronchoscopy under general anaesthesia. In addition to our standard airway management with face mask ventilation and rigid bronchoscopy, all patients were temporarily ventilated with an laryngeal tube. Also, in patients requiring laryngeal biopsies, endotracheal intubation was performed with a 6.0 mm microlaryngeal tracheal tube. Minute ventilation volumes, tidal volumes, ventilation pressures, end-expiratory CO2 concentration, oxygen saturation and arterial blood gas samples were measured. Results: From 54 enrolled patients only patients with relevant tumour masses were evaluated (n = 23). Mask ventilation was performed without difficulty in 15 of 23 patients. Mechanical ventilation with the laryngeal tube was possible in 22 of 23 patients with an audible leak present in three. Conventional endotracheal intubation was successfully performed in 19 of 23 patients. During face mask ventilation, minute volume, tidal volume, ventilation pressure, end-tidal CO2, oxygen saturation and arterial PO2 were significantly lower and PCO2 significantly higher (P < 0.05, paired t-test). No statistically significant differences were noted between the laryngeal tube and the microlaryngeal tracheal tube. Conclusions: The possibility of difficult ventilation and intubation must always be considered in patients with supraglottic airway tumours. In these cases, the laryngeal tube can be considered for routine airway management and may be useful in the ‘cannot-intubate’ situation although difficulties should be anticipated in patients with previous irradiation, specifically of the throat area.

We have investigated the cardiovascular and plasma noradrenaline response to surgical incision under sevoflurane anaesthesia and determined the end-tidal concentration of sevoflurane that blocks the adrenergic response or responses to surgical incision (MACBAR) and changes in mean arterial pressure (MAP) in response to surgical incision (MACBCR) in 50% of women. We randomly assigned 64 female patients, aged 20–49 years, to eight groups according to end-tidal sevoflurane concentration: 5.0%, 5.5%, 6.0%, 6.5%, 7.0%, 7.5%, 8.0% and 8.5%. All patients received only sevoflurane anaesthesia. An increase of 10% or more from prestress (incision) values of MAP or plasma noradrenaline concentration was considered a positive response. The probability of no response to stress was analysed using logistic regression to obtain the probability of no response vs. end-tidal sevoflurane concentration and the best-fit curve from the maximum likelihood estimators of the model parameters. MACBAR (mean±SE) was 8.0±0.2%, MACBCR was 7.9±0.2%. However, such high doses of sevoflurane cannot be used clinically because of their high toxicity. It may be preferable to combine sevoflurane with other anaesthetics to reduce haemodynamic responses to strong stimulation.

Background and objective Minimal- and low-flow anaesthesia (fresh gas flow below 1 L min−1) provide many advantages, including reduced cost, conservation of body heat and airway humidity. An airtight seal is essential between the airway device and the airway of the patient. Therefore, we investigated whether the airtight seal created by a laryngeal mask airway allows controlled ventilation of the lungs when the fresh gas flow is reduced to 0.5 L min−1 and compared this with an endotracheal tube.

Methods In a prospective clinical study, 207 patients were managed using a laryngeal mask or an endotracheal tube. After intravenous induction of anaesthesia and 15 min of high fresh gas flow, the flow was reduced to 0.5 L min−1. The breathing system was monitored for airway leaks, and the patients were assessed for complications after airway removal and postoperative discomfort.

Results Both the laryngeal mask and endotracheal tube allowed fresh gas flow reduction to 0.5 L min−1 in 84.7% and 98.3% of cases respectively (small leaks: 12% laryngeal mask, 1.7% endotracheal tube). Three patients with the laryngeal mask (3.3%l) had airway leaks that were too large to permit any reduction in the fresh gas flow.

Conclusions The use of the laryngeal mask airway was more likely to be associated with a gas leak than use of an endotracheal tube; however, if modern anaesthesia machines and monitors are used, in 96.7% of the patients managed with a laryngeal mask a reduction in the fresh gas flow to 0.5 L min−1 was possible. The incidence of coughing and postoperative complaints (sore throat, swallowing problems) was higher after use of an endotracheal tube.

Background and objective: To evaluate the efficacy and optimal dose of prophylactic intravenous ephedrine for the prevention of maternal hypotension associated with spinal anaesthesia for Caesarean section.

Methods: After patients had received an intravenous preload of 0.5 L of lactated Ringer's solution, spinal anaesthesia was administered in the sitting position with hyperbaric bupivacaine 2.5 mL 0.5% combined with 25 μg fentanyl. A total of 68 patients were randomized to receive a simultaneous 2 mL bolus intravenously of either 0.9% saline (Group C, n = 20), ephedrine 6 mg (Group E-6, n = 24), or ephedrine 12 mg (Group E-12, n = 22). Further rescue boluses of ephedrine 6 mg were given if systolic arterial pressure fell to below 90 mmHg, greater than 30% below baseline, or if symptoms suggestive of hypotension were reported.

Results: There was a significantly higher incidence of hypotension in Group C (60% patients) compared to Group E-12 (27%), but not in Group E-6 (50%). The 95% Confidence Interval for the difference in proportions between Groups C and E-12 was 6-60%, P < 0.05. Fewer rescue boluses of ephedrine were required in Group E-12 compared with Group C (1.8 ± 1.2 vs. 3.3 ± 2.1, P < 0.05). There were no significant differences in the incidence of maternal nausea or vomiting, or of neonatal acidaemia between groups.

Conclusion: A prophylactic bolus of ephedrine 12 mg intravenously given at the time of intrathecal block, plus rescue boluses, leads to a lower incidence of hypotension following spinal anaesthesia for elective Caesarean section compared to intravenous rescue boluses alone.

Summary

Background and objective: Remifentanil boluses are used in different clinical situations and the effects on bispectral index monitoring are unclear. We analysed the effect of a remifentanil bolus on the bispectral index of the electroencephalogram (bispectral index) under total intravenous anaesthesia with propofol and remifentanil. Methods: ASA I–III patients were included in this study. All patients received a 2 μg k g−1 remifentanil bolus in a period free from stimuli. Bispectral index and haemodynamic data were collected from an A-2000XP bispectral index monitor (every second) and an AS/3 Datex monitor (every 5 s). Bispectral index data were analysed using the area under the curve. Mean arterial pressure and heart rate were averaged at each 30-s period and analysed using analysis of variance. Results: A total of 240 bispectral index values were obtained per patient. The area under the curve between 90 and 120 s after the bolus was significantly lower than the basal area under the curve (average of all areas before the bolus, P < 0.05). Mean arterial pressure and heart rate were significantly reduced from 96.4 ± 19.9 mmHg at the time of the bolus to 74.2 ± 16.6 mmHg 120 s after, and from 70 ± 16.4 bpm at the time of the bolus to 61 ± 13.6 bpm after (P < 0.001), respectively. Conclusions: There was a significant reduction in the areas under the curve between 90–120 s following the bolus. Heart rate and blood pressure also showed significant reductions. Thus, remifentanil bolus given under total intravenous anaesthesia with propofol and remifentanil decreases bispectral index, an effect independent of intubation and surgical stimuli.

Summary

Background and objective: Bispectral Index® correlates with depth of hypnosis in adult patients. Bispectral index monitoring has been separately examined and validated during both mild and moderate hypothermic cardiopulmonary bypass. However, the effect on bispectral index of these two differing cardiopulmonary bypass temperature regimes has not previously been compared, particularly with the use of volatile anaesthetic agents. Methods: Following Institutional Ethics Committee approval and informed consent, 30 patients undergoing coronary artery bypass grafting had additional bispectral index monitoring. Sixteen patients had mild hypothermic bypass (32–34°C), and 14 had moderate hypothermic bypass (28–30°C). Anaesthesia was standardized, and was maintained with enflurane throughout surgery. Scores were recorded at 14 specific event-related time points during surgery. Results: This study has demonstrated that in this adult population, a relationship exists between bispectral index score and temperature throughout the duration of cardiac surgery, which included mild or moderate hypothermic cardiopulmonary bypass. It also demonstrated that patients which were categorized as having received moderately hypothermic cardiopulmonary bypass had lower bispectral index scores than those patients who received mild hypothermic cardiopulmonary bypass, at time points corresponding approximately with median steady-state bypass temperature, pre-re-warming and early re-warming periods. Conclusions: Moderate hypothermic cardiopulmonary bypass has lower bispectral index scores when compared to mild hypothermic cardiopulmonary bypass, at a steady state of inspired enflurane. This may reflect an actual increase in the depth of hypnosis. However, as this study did not address the physico-chemical changes of the volatile agent or the accuracy of the bispectral index algorithm at lower temperatures, we would not advocate a change in practice based solely on this report.

Summary

Background and objective: Oral morphine may be useful for postoperative pain relief, but few studies have tested its use after in-hospital surgery. Methods: We evaluated clinical efficacy and the pharmacokinetic parameters of oral morphine after total hip arthroplasty. We recruited 60 patients who had total hip arthroplasty under general anaesthesia. The patients were randomized to receive placebo, 10 mg morphine sulphate or 20 mg morphine sulphate orally every 4 h for 24 h. The oral administration was started 3 h after the morphine-loading dose in the Post Anaesthesia Care Unit and then patients used intravenous morphine patient-controlled analgesia for 24 h. Pain score at rest (scored by patients on a visual analogue scale), sedation, nausea, vomiting and urinary retention were monitored. In 11 additional total hip arthroplasty patients, we determined the pharmacokinetics of morphine and its metabolites after oral administration of 20 mg morphine sulphate every 4 h for 16 h. Results: The amount of morphine administered via patient-controlled analgesia over 24 h was reduced in the 20-mg group compared with that in the placebo group (19.0 ± 2.7 mg vs. 33.0 ± 5.5 mg; P = 0.03). No significant morphine-sparing effect was observed in the 10-mg group. Pain scores and side-effects were similar in all groups. The pharmacokinetic study revealed a limited and slow absorption of morphine. Conclusion: Despite a limited absorption of oral morphine postoperatively, high doses of oral morphine have a significant analgesic effect after total hip arthroplasty.

Summary

Background and objectives: Preoperative evaluation performed by anaesthesiologists primarily aims to estimate the risk of perioperative complications and to create opportunities to optimize the patients' condition before surgery. In this study an inventory was made of the current practice of preoperative evaluation in Dutch hospitals. It was estimated how many hospitals had implemented an outpatient preoperative evaluation clinic in 2004. Subsequently, current practice was compared with the results of a previous inventory (2000). It was also evaluated to what extent the guidelines of the Dutch Health Council and the Netherlands Society of Anaesthesiology were followed. Methods: The study consisted of two phases. First, a literature research was performed and pilot interviews were constructed. The interviews were conducted face-to-face with anaesthesiologists in a sample of Dutch hospitals. Based on the results, written questionnaires were constructed. In the second phase these questionnaires were sent to all general and academic hospitals in the Netherlands. Results: In 2004, 74% of the hospitals had an outpatient preoperative evaluation clinic, compared with 50% in 2000. The percentage of hospitals with an outpatient preoperative evaluation clinic available for all elective patients increased from 20% to 52%. Conclusions: The Dutch guidelines on preoperative evaluation seem to have influenced current practice. An increase in the number of outpatient preoperative evaluation clinics was seen after the guidelines were published. The implementation of an outpatient preoperative clinic seems to warrant that anaesthesiologists are carrying out the activities prescribed by the guidelines. Most hospitals without a clinic aim to implement one in the future.

This study was designed to determine whether low doses of intrathecal morphine still result in itching and it evaluates the outcome of a standardized treatment using promethazine and – for intractable itch – naloxone. Patients (n = 143) scheduled for total hip surgery were allocated to four groups (in a double blind manner) with bupivacaine 20 mg in 4 mL but different doses of intrathecal morphine: Group I, 0.025 mg, Group II, 0.05 mg, Group III, 0.1 mg and Group IV, 0.2 mg. The presence or absence of itching was noted every three hours for a 24-h period. When required, standardized treatment was provided. The incidence of itching was: Group I: 14.3%; Group II: 21.6%; Group III: 48.6%; and, Group IV: 61.7%. Itch was treated by administering promethazine intramuscularly in 2.9% (Group I); 8.1% (Group II); 10.8% (Group III), and 8.9% (Group IV), respectively. Only in group IV there was a single patient who needed naloxone to treat itching. The incidence and severity of itching is a dose-related side-effect in the dose range of 0.025–0.2 mg of intrathecal morphine. Itching still occurs after the low doses of intrathecal morphine, but symptoms vanish after promethazine 25 mg intramuscularly.

Summary

Backgrounds: The purpose of this study was to evaluate the effect of ephedrine and phenylephrine on propofol concentrations and bispectral index during propofol anesthesia. Methods: General anaesthesia was induced with propofol and was maintained with propofol (4 mg kg−1 h−1) and fentanyl. Vecuronium was used to facilitate the artificial ventilation of the lungs. Patients with systolic blood pressure > 90 mmHg were defined as the control group (n = 16). Patients who had to be treated for larger decreases in arterial blood pressure (systolic blood pressure <90 mmHg) were randomly assigned to receive ephedrine 0.1 mg kg−1 (n = 20) or phenylephrine 2 μg kg−1 (n = 20). Propofol concentrations were determined before (baseline) and at 3 and 10 min after the administration of ephedrine or phenylephrine. Bispectral index was monitored continuously. Cardiac output was determined using a pulmonary arterial catheter. Results: Ten minutes after drug injection, bispectral index in the ephedrine group increased significantly compared with the baseline and was significantly larger than that in the control or phenylephrine group. Eight patients in the ephedrine group had bispectral index >60, whereas no patient in the control or phenylephrine groups had bispectral index >60. There were no significant differences in propofol concentrations or cardiac output relative to baseline at 3 or 10 min after the administration of ephedrine or phenylephrine. Conclusions: Ephedrine increases bispectral index values without decreasing propofol concentrations during general anesthesia.

A non-invasive ultrasound imaging technique (BladderScan) was used prospectively in an attempt to reduce the need for catheterization of the urinary bladder and the incidence of urinary tract infections after orthopaedic surgery. Over a 4-month period, in which 1920 patients were included, catheterization was performed if there was no spontaneous diuresis by 8 h after surgery. A total of 31% of these patients were catheterized, and 18 patients developed urinary tract infections. In a subsequent 4-month period, there were 2196 patients, catheterization was performed only if the bladder volume was more than 800 mL 8 h after surgery. The rate of catheterization decreased to 16%, and five patients developed urinary tract infections. In our patients, measuring bladder volume reduced the need for a urinary catheter and the likelihood of urinary infection.

Summary

Background and objective: To evaluate the effects of sevoflurane and desflurane in combination with intravenous remifentanil on time for discharge from the postanaesthesia care unit and need for postanaesthesia care unit management after elective laparoscopic cholecystectomy. Methods: 231 ASA Grade I–II patients, undergoing elective laparoscopic cholecystectomy in seven University teaching hospital, were randomly allocated to receive a desflurane–remifentanil (n = 105) or sevoflurane–remifentanil (n = 126) anaesthetic. A blinded observer recorded times for emergence and postanaesthesia care unit discharge (achievement of an Aldrete score ≥9), number of patients eligible for postanaesthesia care unit discharge when exiting the operating room and occurrence of adverse events. Results: Intraoperative cardiovascular stability was similar in the two groups. Emergence, response and extubation occurred earlier after desflurane (5.4 ± 3 min, 5.5 ± 3 min and 7.5 ± 4 min) than sevoflurane (6.6 ± 3.5 min, 7.2 ± 4 min and 9.1 ± 4.2 min) (P = 0.0005, 0.05 and 0.003, respectively). Postanaesthesia care unit bypass was possible in 44 desflurane–remifentanil patients (41%) and 55 sevoflurane– remifenatnil patients (43%) (P = 0.69), while postanaesthesia care unit discharge occurred after 46 min (25th–75th percentiles: 18–40 min) with desflurane and 64 min (25th–75th percentiles: 20–50 min) with sevoflurane (P = 0.04). Postoperative nausea and vomiting was observed in 40 desflurane–remifentanil patients (36%) and 53 sevoflurane–remifentanil patients (42%) (P = 0.42). Conclusions: Both the desflurane–remifentanil and sevoflurane–remifentanil combinations provide a similarly adequate intraoperative cardiovascular stability. Emergence and postanaesthesia care unit discharge were faster with desflurane–remifentanil than sevoflurane–remifentanil, but this was not associated with a larger proportion of postanaesthesia care unit bypass, confirming that no clinically relevant differences are present between the two agents.

In order to compare interscalene brachial plexus block performed with ropivacaine or bupivacaine, 45 healthy, unpremedicated patients, undergoing elective shoulder surgery, were randomly allocated to receive interscalene brachial plexus anaesthesia with 20 mL of either ropivacaine 0.75% (n=15), ropivacaine 1% (n=15), or bupivacaine 0.5% (n=15). Readiness for surgery (loss of pinprick sensation from C4 to C7 and inability to elevate the limb from the bed) was achieved later with bupivacaine 0.5% (28±15 min) than with ropivacaine 1% (10±5 min) (P=0.005) and ropivacaine 0.75% (15±8 min) (P=0.0005). No differences in success rate were observed between the three groups; however, seven patients receiving bupivacaine 0.5% required intra-operative analgesic supplementation (fentanyl 0.1 mg intravenous) compared with one patient receiving ropivacaine 0.75%, and two patients treated with ropivacaine 1% (P=0.02). The time from the block placement to first request for pain medication was similar in the three groups (10.7±2 h, 11±2.4 h, and 10.9±3.9 h after 0.75% and 1% ropivacaine or 0.5% bupivacaine, respectively). We conclude that interscalene brachial plexus block performed with 20 mL of either 0.75% or 1% ropivacaine allows for a prolonged post-operative pain relief, similar to that provided by bupivacaine 0.5%, with short onset time of surgical anaesthesia.