Summary

Background and objectives: Infraclavicular plexus block has many advantages of particular interest in the emergency setting. However, the number of nerve stimulations needed to optimize the technique remains unclear. We evaluated both the local anaesthetic requirement and the success rate of Sim's derived infraclavicular plexus block performed with a nerve stimulator when either one or two responses were sought. Methods: In this prospective study, 50 patients who presented for distal upper limb surgery were randomized into two groups: in Group 1, ropivacaine 0.75% 40 mL was injected when nerve stimulation elicited a distal motor response (median, ulnar or radial). In Group 2, only 30 mL of the same local anaesthetic was injected, 7 mL to the musculocutaneous nerve and 23 mL to the median, ulnar or radial nerves. Sensory and motor blocks were tested at 5-min intervals over 30 min. Results: The time to perform the block was similar in both groups. The success rate of the block increased from 80% in the single-stimulation group to 92% in the double-stimulation group (not significant). The onset time of sensory and motor block was shorter and block extension was greater in ulnar, antebrachial cutaneous and brachial cutaneous nerve distributions in the multistimulation group (P < 0.05). Conclusions: We conclude that only 30 mL of local anaesthetic seems to be sufficient to ensure a high level of success when performing an infraclavicular block with stimulation of both the musculocutaneous nerve and median, ulnar or radial nerve.

Summary

Background and objective: To assess the knowledge, beliefs and attitudes of anaesthesia providers on the patients' possible intraoperative visual experiences during cataract surgery under local anaesthesia. Methods: Anaesthesia providers from the Ophthalmic Anaesthesia Society (USA); British Ophthalmic Anaesthesia Society (UK); Alexandra Hospital, National University Hospital, Tan Tock Seng Hospital, Singapore General Hospital and Changi General Hospital (Singapore) were surveyed using a structured questionnaire. Results: A total of 146 anaesthesiologists (81.6%), 10 ophthalmologists (5.6%) and 23 nurse anaesthetists (12.8%) responded to the survey. Most respondents believed that patients would experience light perception and many also felt that patients might encounter other visual sensations such as movements, flashes, colours, surgical instruments, hands/fingers and the surgeon during the surgery. A significantly higher proportion of anaesthesia providers with previous experience of monitoring patients under topical anaesthesia believed that patients might experience the various visual sensations compared to those who have not previously monitored. For both topical and regional anaesthesia, anaesthesia providers who routinely counsel their patients are (1) more likely to believe that preoperative counselling helps or (2) were previously told by patients that they could see intraoperatively and/or that they were frightened by their visual sensations. These findings were statistically significant. Conclusions: The majority of anaesthesia providers in the USA, UK and Singapore are aware that patients may experience a variety of visual sensations during cataract surgery under regional or topical anaesthesia. Those who have previously managed patients undergoing cataract surgery under topical anaesthesia are more likely to believe this compared to those who have not.

Summary

Background and objective: Sub-Tenon's block is usually delivered by the infero-nasal (IN) approach, but occasionally this may not be possible. The infero-temporal (IT) approach has been described, but data is not available on its efficacy. Methods: One hundred patients undergoing cataract extraction were randomized to receive an IN or IT sub-Tenon's injection of lidocaine 2% with hyaluronidase 15 IU mL−1. Akinesia was assessed using the Brahma scale at 0, 2, 4, 6 and 8 min. Injection, intraoperative and postoperative pain scores (verbal analogue score, 0–10) were noted, along with the incidence of sub-conjunctival haemorrhage and chemosis. Results: There were no differences in patient characteristics data, or mean volume of administered local anaesthetic solution (3.3 (SD = 0.4) mL). There were no significant differences between groups in terms of onset of akinesia. Mean akinesia scores at 2, 4, 6 and 8 min were 2.7, 1.1, 0.4 and 0.2 for Group IN, compared to 2.2, 0.9, 0.8 and 0.3 for Group IT. Chemosis occurred in 14 patients in Group IN, compared to 22 in Group IT (P = 0.21).A sub-conjunctival haemorrhage was noted in 14 patients in Group IN and 19 patients in Group IT (P = 0.52). No patients required supplementary injections. Mean pain scores for the injection, intraoperatively and postoperatively were 0.9, 0 and 0 for Group IN, compared to 1.1, 0 and 0 for group IT. The surgeons scored all the blocks as ‘good’ except for one patient in each group. Conclusions: The IT approach provides an equally rapid onset of block, without a significant increase in complications.

Summary

Background and objective: The quality of spinal anaesthesia, often used for Caesarean section, can be improved by adding an opioid to the local anaesthetic. This study compared the quality of anaesthesia, postoperative analgesia, and adverse effects on mother and neonate when either sufentanil 5 μg or morphine 0.2 mg was added to intrathecal hyperbaric bupivacaine for Caesarean section. Methods: This prospective, randomized and double-blind study encompassed 54 females undergoing Caesarean section. Spinal anaesthesia was obtained with 2 mL of 0.5% bupivacaine supplemented with either 0.2 mg morphine or 5 μg sufentanil. Characteristics of spinal block, intraoperative analgesia, maternal and neonatal side-effects and the time to first request for analgesics were assessed. Results: There were no differences in the onset time of sensory block, time to sensory block to T10, time to highest sensory block, highest sensory block level, time to regression of sensory block to T10 level and time to resolution of motor blockade. Perioperative haemodynamic parameters, neonatal Apgar scores, neurological and adaptive capacity scores, umbilical blood gas values, sedation scores, nausea–vomiting and pruritus incidences were similar in both groups. The time to the first request for an analgesic was significantly longer (19.5 ± 4.7 h vs. 6.3 ± 5.2 h) in patients given morphine (P < 0.05). Conclusions: The addition of 5 μg sufentanil or 0.2 mg morphine to hyperbaric bupivacaine for Caesarean section both provided safe and effective anaesthesia. Morphine increased the duration of postoperative analgesia compared with sufentanil without increasing maternal or neonatal side-effects.

Summary

Background and objective: To measure ‘depth of anaesthesia’, anaesthesiologists use a combination of observable end-points such as immobility and autonomic stability. Unconsciousness and amnesia are not reliably observable end-points, but correlate with parameters derived from the electroencephalogram. We investigated the association of subjective assessment and electroencephalographic measures of anaesthetic depth in a group of experienced (>4 yr of experience) and a group of inexperienced (<2 yr of experience) anaesthesiologists. Methods: One hundred ASA I or II patients were assigned to either group. Anaesthesiologists assessed ‘anaesthetic depth’ using an 11-point numeric and a 5-point verbal scale. Bispectral index and spectral entropy were recorded as electroencephalogram parameters. The association between the subjective assessment and the electroencephalogram parameters was calculated using the prediction probability, PK. Results: Association between subjective assessment and electroencephalographic parameters showed a tendency to a better prediction probability in the experienced group. The difference was significant (P < 0.05) for the bispectral index (PK 0.76 ± 0.01 for experienced and 0.71 ± 0.01 for inexperienced anaesthesiologists). In both groups, a large percentage of the data points recorded during surgery showed bispectral index values above the recommended value of 60 (13.2% in the experienced and 34.3% in the inexperienced group) despite a subjective assessment of ‘deep’ or ‘very deep’ anaesthetic depth. Conclusion: The study demonstrates that the association between subjectively assigned values of anaesthetic depth and electroencephalographic parameters of anaesthetic depth is better for anaesthesiologists with more clinical experience. However, in the ‘inexperienced’ as well as ‘experienced’ group a high percentage of bispectral index and entropy values above 60 occurred despite a subjective assessment of adequate anaesthetic depth. Although there was no evidence for explicit memory, this may indicate a risk for memory formation.

Summary

Background and objectives: The primary objective of sedation in the critically ill patient is to achieve security and comfort. The routine use of standardized and validated sedation scales and monitors are needed. The Richmond agitation sedation scale has been used but some patients cannot be evaluated with subjective assessment tools such as the Richmond agitation sedation scale because they lack motor responsiveness due to therapeutic paralysis or because they are receiving deep sedation. We aimed to assess the correlation of bispectral index with Richmond agitation sedation scale during dexmedetomidine sedation and evaluate the use of the bispectral index in monitoring the levels of sedation in intensive care patients. Methods: This was a single centre, prospective, clinical study. Eleven mechanically-ventilated critically ill patients, aged 17–82 (50.09 ± 17.76; mean ± SD) yr, 3 males and 8 females, APACHE II score 12.63 ± 3.90, SOFA score 3.27 ± 1.73 were enrolled in the study. Patients received a dexmedetomidine infusion of 1 μg kg−1 over 10 min followed by a maintenance infusion of 0.5 μg kg−1 h−1 for 8 h. Sedation was assessed using the Richmond agitation sedation scale and bispectral index monitoring. Heart rate, blood pressure, respiratory rate and SPO2 were monitored. Wilcoxon signed rank sum test and Spearman's rank correlation analysis were used for statistical analysis. Results: The variation of Richmond agitation sedation scale score was between 0.9 and −1.7 bispectral index varied from 65 to 75. Significant correlations between Richmond agitation sedation scale and bispectral index values were found in this study. (r = 0.900; P = 0.0001) Conclusions: Richmond agitation sedation scale levels significantly correlated with bispectral index values during dexmedetomidine sedation in critically ill patients requiring mechanical ventilation in the intensive care unit.

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 objectives: A difficult issue in anaesthesia is its titration for an individual patient to avoid over- and underdosage. Common practice is to use an initial dose and increase it subsequently if the defined end-point is not reached. This assumes that the end-point is reached after a similar interval of time in all patients given a similar dose. In order to test this hypothesis we measured the time to reach end-points such as loss of consciousness (LOC), a bispectral index (BIS®) value of 60, the minimal BIS and the minimal mean arterial pressure (MAP) values. Methods: Thirty patients aged 18–60 yr scheduled for general surgery were included in this observational study. After preoxygenation, induction was performed with 6% inspired concentration of sevoflurane in 6 Lmin−1 oxygen using the SiBI® connector and the tidal volume technique. Remifentanil was administered when the BIS value was 60 and tracheal intubation was performed 4 min later. Results: Time (median, minimum–maximum) to LOC, a BIS value of 60, the minimal BIS and MAP values were, respectively, 75 (45–135), 120 (75–270), 300 (120–720) and 450 (120–1200) seconds. The time to the minimal BIS value was significantly (P < 0.05) shorter than the time to reach the minimal MAP value. Conclusions: These results demonstrate large inter-patient variability for the time necessary to reach defined end-points of depth of anaesthesia when a similar dose of anaesthetic is given. Measuring the time to reach a predefined BIS value would allow application of nociceptive stimuli only at adequate levels of hypnosis and would facilitate titration.

Summary

Background and objective: Whereas the protective effect of anaesthetic and ischaemic preconditioning has been described for several organs, it is uncertain whether this mechanism is also effective in the kidney. We compared the effect of preconditioning with sevoflurane and preconditioning with short episodes of ischaemia on renal ischaemia/reperfusion injury in the rat in vivo. Methods: Fourteen days after right-sided nephrectomy, anaesthetized male Wistar rats were randomly assigned to a sham-operated group (no arterial occlusion, n = 5) or underwent 45 min of left renal artery occlusion (control group, n = 9) followed by 3 days of reperfusion. Two further experimental groups of animals were preconditioned prior to ischaemia either by administering 1 MAC sevoflurane for 15 min followed by 10 min of washout (sevoflurane group, n = 10) or by subjecting the animals to three short episodes of renal ischaemia (ischaemia-preconditioned group, n = 8). Blood creatinine was measured during reperfusion and morphological damage was assessed by histological examination. Results: Baseline creatinine values were similar in all four groups (0.7 ± 0.2 mg dL−1; mean ± SD) and remained unchanged in the sham-operated animals after 3 days (0.8 ± 0.2 mg dL−1). Creatinine levels increased in the ischaemic preconditioning group (3.3 ± 1.2 mg dL−1) and sevoflurane preconditioning group (4.0 ± 1.1 mg dL−1) compared to the control group (1.6 ± 0.6 mg dL−1). Morphological damage was less severe in the control group, i.e. in animals without preconditioning, than in both preconditioning groups. Conclusion: Neither sevoflurane nor ischaemic preconditioning preserves renal function or attenuates cell damage in the rat in vivo.

Summary

Background and objective: Every member of healthcare personnel should be able to perform basic life support including defibrillation (CPR-D). The biggest cost of implementation is training and these costs need to be reduced. The purpose of this randomized study was to evaluate the applicability of distance learning as a method to teach CPR-D. Methods: Nurses (n = 56) working in a geriatric hospital were randomized into three groups. The first group was given the Internet-based CPR-D course and the second was given a traditional, small-group CPR-D course. A third group without specific training in CPR-D served as a control group. An objective structured clinical examination (OSCE) was performed 2 weeks after the courses with a manikin patient having a cardiac arrest. Results: The median score of all participants was 31/49 (range 21–38). The reliability of the checklist was adequate (Cronbach alpha 0.77). Nurses receiving traditional CPR-D performed better than those receiving the Internet-based course (median score 34 vs. 28, P < 0.05) and the control group (median score 34 vs. 26, P < 0.0001). Nurses receiving Internet-based course performed similarly as the control group (median score 28 vs. 26, ns). Conclusions: Distance learning cannot substitute for traditional small-group learning.

Summary

Background and objective: Data from several studies implicate that pre-treatment with non-selective cyclooxygenase inhibitors such as aspirin or diclofenac may decrease the incidence of postoperative succinycholine-related myalgia. We tested the influence of a preoperatively administered selective cyclooxygenase 2 inhibitor, parecoxib, on postoperative myalgia. Methods: After Ethics Committee approval, 68 patients were randomized into two groups (n = 34 each). Group 1 received parecoxib 40 mg intravenously 3 min before induction of anaesthesia, and Group 2 received saline (in a double-blinded manner). Incidence and severity of myalgia was evaluated systematically with a standardized questionnaire 24, 48 and 72 h after anaesthesia. We also the assessed the number of patients who felt limited in their activity due to myalgia. Results: Seven patients in the parecoxib-treated group complained of myalgia compared with 11 in the control group (not significant). No significant difference in the severity of myalgia or in the limitation of patients activity was found between the groups. Conclusion: Intravenous parecoxib 40 mg, when administered before induction of anaesthesia, did not reduce incidence and severity of postoperative myalgia and did not improve activity in those who suffered from myalgia.

Abstract

Background: Postoperative nausea and vomiting still represents a major problem after surgery. Although risk factors for postoperative nausea and vomiting and procedures to reduce postoperative nausea and vomiting have been described, the incidence of postoperative nausea and vomiting remains high. The aim of the present study was to investigate the potential role of the proton pump inhibitor esomeprazole to reduce postoperative nausea and vomiting after elective surgery. Methods: In a randomized, double-blind trial, ASA I–III patients at high risk for postoperative nausea and vomiting received esomeprazole tablets 3 × 40 mg or matching placebo the evening before surgery, 2 h preoperatively and 24 h postoperatively. Total intravenous anaesthesia with propofol and remifentanil without nitrous oxide (FiO2 0.5) was used. Patients were interviewed using a standardized postoperative nausea and vomiting questionnaire at discharge from the post-anaesthesia care unit, 6 h and 24 h later. The severity of nausea was estimated on a 0–100 point numerical scale (0 = no nausea, 100 = maximum nausea). Results: The incidence of vomiting was similar in the esomeprazole (n = 45) and the placebo (n = 48) groups (64.4% vs. 60.5%, P > 0.05). The average nausea score was 17.8 with esomeprazole and was 18.7 with placebo (P > 0.05). Only 24.7% of all patients (esomeprazole 24.4%, placebo 25.0%) did not experience any nausea or vomiting. Conclusion: There is no evidence that prophylactic esomeprazole reduces the incidence of postoperative nausea and vomiting or the degree of postoperative nausea.

Summary

Background and objective: We compared the dose requirement and side effect profile of total intravenous anaesthesia using Diprivan® to generic propofol at a specific anaesthetic target level utilizing the bispectral index monitor to determine efficacy differences between the two products. Methods: Sixty women undergoing abdominal hysterectomy were induced with propofol 2 mg kg−1 and maintained with infusion (20–200 μg kg−1 min−1) adjusted to maintain a bispectral index of 50–65. Plasma propofol concentration was measured at 1 and 2 h post induction in 25 patients. Results: Mean (SD) drug doses adjusted for weight and time were similar in the Diprivan® and generic propofol groups: 90 (30) μg kg−1 min−1 vs. 90 (20) μg kg−1 min−1 respectively. Mean (SD) plasma propofol levels at 1 and 2 h were also similar (3.0 (1.0) μg mL−1 vs. 3.6 (1.4) μg mL−1, P = 0.2 and 3.0 (1.9) μg mL−1 vs. 3.4 (1.6) μg mL−1, P = 0.58). Conclusions: Diprivan® and generic propofol have similar efficacy at a specified, bispectral index-defined, depth of anaesthesia.

Summary:

Background and objective: Several new techniques and agents (e.g. ropivacaine) have been introduced in regional anaesthesia to improve patients outcome and safety. The beneficial effects on patient outcome are clear with these techniques, however, no information is available about their pattern and frequency of use in clinical practice. This study presents data concerning the current practice of regional anaesthesia in Germany. Methods: A questionnaire was sent to every German anaesthesia department (n = 1381). Questions focused on the frequency and range of regional anaesthetic procedures employed, with attention also to the organizational structural of the individual institution. Results: Six hundred and sixty-seven questionnaires were returned anonymously, representing a return rate of 48.3%. In hospitals with less than 200 beds, the number of regional anaesthetics was markedly higher compared to large hospitals with more than 400 beds. In contrast, small hospitals tended to provide only basic techniques of regional anaesthesia, whereas larger hospitals implemented more advanced techniques. Bupivacaine remains the most commonly used long-lasting local anaesthetic. Staff structure was also different in small departments – patient care was performed by board certified anaesthesiologists while residents were responsible for the patients in larger departments. Conclusions: In small hospitals a majority of board certified anaesthesiologists rely on basic regional anaesthesia techniques. In large departments some consultants provide the entire spectrum of regional anaesthesia, with the majority of cases transferred to the residents responsibility. These results indicate the strong need to improve residency programs with regard to regional anaesthesia.