Showing papers in "Anaesthesia in 2008"

A procedure-specific systematic review and consensus recommendations for postoperative analgesia following total knee arthroplasty

Abstract: The PROSPECT Working Group, a collaboration of anaesthetists and surgeons, conducts systematic reviews of postoperative pain management for different surgical procedures (http://www.postoppain.org). Evidence-based consensus recommendations for the effective management of postoperative pain are then developed from these systematic reviews, incorporating clinical practice observations, and transferable evidence from other relevant procedures. We present the results of a systematic review of pain and other outcomes following analgesic, anaesthetic and surgical interventions for total knee arthroplasty (TKA). The evidence from this review supports the use of general anaesthesia combined with a femoral nerve block for surgery and postoperative analgesia, or alternatively spinal anaesthesia with local anaesthetic plus spinal morphine. The primary technique, together with cooling and compression techniques, should be supplemented with paracetamol and conventional non-steroidal anti-inflammatory drugs or COX-2-selective inhibitors, plus intravenous strong opioids (high-intensity pain) or weak opioids (moderate- to low-intensity pain).

Mortality and utilisation of critical care resources amongst high-risk surgical patients in a large NHS trust*

Abstract: Previous reports describe a population of non-cardiac surgical patients at high risk of complications and death Outcomes are sub-optimal for such patients, perhaps in part related to inadequate provision or ineffective utilisation of critical care resources In this study, data describing 26,051 in-patient non-cardiac surgical procedures performed in a large NHS Trust between April 2002 and March 2005 were extracted from local databases Of these procedures, 2 414 (93%) were high risk with an overall mortality rate of 122% and a prolonged hospital stay (high-risk population median (IQR) 16 (9-30) days vs standard risk 3 (2-6) days) Mortality rates for specific procedures were consistent with UK averages However, only 852 (353%) high-risk patients were admitted to a critical care unit at any stage after surgery Of 294 high-risk patients who died, only 144 (490%) were admitted to a critical care unit at any time and only 75 (256%) of these deaths occurred within a critical care area Mortality rates were high amongst patients discharged and readmitted to critical care (377%) and amongst those admitted to critical care following initial postoperative care on a standard ward (299%) These data suggest that the outcome of high-risk general surgical patients could be improved by adequate provision and more effective utilisation of critical care resources

Evaluation of the Airtraq® and Macintosh laryngoscopes in patients at increased risk for difficult tracheal intubation*

Abstract: Summary The Airtraq � , a novel single use indirect laryngoscope, has demonstrated promise in the normal and simulated difficult airway. We compared the ease of intubation using the Airtraq with the Macintosh laryngoscope, inpatients at increased risk for difficult tracheal intubation, in a randomised, controlled clinical trial. Forty consenting patients presenting for surgery requiring tracheal intubation, who were deemed to possess at least three characteristics indicating an increased risk for difficulty in tracheal intubation, were randomly assigned to undergo tracheal intubation using a Macintosh (n = 20) or Airtraq (n = 20) laryngoscope. All patients were intubated by one of three anaesthetists experienced in the use of both laryngoscopes. Four patients were not successfully intubated with the Macintosh laryngoscope, but were intubated successfully with the Airtraq. The Airtraq reduced the duration of intubation attempts (mean (SD); 13.4 (6.3) vs 47.7 (8.5) s), the need for additional manoeuvres, and the intubation difficulty score (0.4 (0.8) vs 7.7 (3.0)). Tracheal intubation with the Airtraq also reduced the degree of haemodynamic stimulation and minor trauma compared to the Macintosh laryngoscope.

A quantitative review and meta-analysis of performance of non-standard laryngoscopes and rigid fibreoptic intubation aids.

Abstract: This quantitative review summarises studies of rigid fibreoptic laryngoscopy systems. In 6622 'normal' patients only the Bonfils and CTrach had homogenous data and first time intubation success rates above 90%. In 1110 patients predicted or known to be difficult to intubate only the Bonfils, CTrach and Glidescope had homogenous data and first-time success rates above 90%. In comparative studies with the Macintosh-3 blade, no device had homogenous data in more than one study. Many devices had higher summed performances, but due to data heterogeneity, interpretation is very difficult, if worthwhile at all. The currently available data do not provide strong evidence that these devices should supersede standard direct laryngoscopy for routine or difficult intubation. Further research needs to be of high quality, studying relevant patients to create such evidence. Multicentre collaborations are likely to be needed studying known difficult patients or creating databases reporting the success/failure rate of these devices.

A prospective audit of regional anaesthesia failure in 5080 Caesarean sections.

Abstract: Anaesthesia for Caesarean section was audited over a 5 year period: 5080 cases were performed using spinal 63%, epidural top-up 26%, combined spinal-epidural 5% and primary general anaesthesia 5%. The rate of general anaesthesia conversion of regional anaesthesia was 0.8% for elective and 4.9% for emergency Caesarean section compared to Royal College of Anaesthetists targets of 1% and 3%. The rate of conversion of regional to general anaesthesia in category 1 Caesarean section was 20%. A total of 8% of women had general anaesthesia when both primary general and conversion of regional anaesthesia were combined. The rate of failure to achieve a pain-free operation was 6% with spinals, 24% with epidural top-up and 18% with combined spinal-epidural. Besides the type of anaesthesia and operative urgency, other factors associated with pre-operative failure of regional anaesthesia included body mass index, no previous Caesareans, and indication for Caesarean of acute fetal distress or maternal medical condition. Inadequacy of pre-operative anaesthetic block and duration of surgery were important risk factors for intra-operative failure. For spinal anaesthesia, use of a spinal opioid was associated with less pre-operative failure. For epidural top-up anaesthesia, lower epidural top-up volume was associated with less pre-operative failure, and use of adrenaline was associated with both less pre-operative and intra-operative failure. The rate of serious adverse incidents was 1 : 126 with general anaesthesia and 1 : 501 with regional anaesthesia.

Delirium is associated with early postoperative cognitive dysfunction.

Abstract: The purpose of this analysis was to determine if postoperative delirium was associated with early postoperative cognitive dysfunction (at 7 days) and long-term postoperative cognitive dysfunction (at 3 months). The International Study of Postoperative Cognitive Dysfunction recruited 1218 subjects >or= 60 years old undergoing elective, non-cardiac surgery. Postoperatively, subjects were evaluated for delirium using the criteria of the Diagnostic and Statistical Manual. Subjects underwent neuropsychological testing pre-operatively and postoperatively at 7 days (n = 1018) and 3 months (n = 946). Postoperative cognitive dysfunction was defined as a composite Z-score > 2 across tests or at least two individual test Z-scores > 2. Subjects with delirium were significantly less likely to participate in postoperative testing. Delirium was associated with an increased incidence of early postoperative cognitive dysfunction (adjusted risk ratio 1.6, 95% CI 1.1-2.1), but not long-term postoperative cognitive dysfunction (adjusted risk ratio 1.3, 95% CI 0.6-2.4). Delirium was associated with early postoperative cognitive dysfunction, but the relationship of delirium to long-term postoperative cognitive dysfunction remains unclear.

Evaluation of the size 4 i-gel airway in one hundred non-paralysed patients.

Abstract: We studied the i-gel in 100 elective, anaesthetised patients (55:45 male:female, median age 53 years) assessing: ease of use, airway quality, positioning, seal and complications. First insertion attempt was successful in 86 patients, second attempt in 11 patients, and third attempt in three patients. Fifty three manipulations were required in 26 patients (median 1) to achieve a clear airway. Median insertion time was 15 s. During ventilation, expired tidal volume of 7 ml x kg(-1) was achieved in 96 (96%) patients. Median airway leak pressure was 24 cmH(2)O. On fibreoptic examination via the device, vocal cords were visible in 87 patients (91%). During maintenance, six patients (6%) required 12 airway manipulations. There was one episode of regurgitation, without aspiration. Other complications and patient side-effects were mild and few. The i-gel is easily and rapidly inserted, providing a reliable airway in over 90% of cases. Further studies are indicated to assess safety and performance compared to other supraglottic airway devices.

Patient safety incidents associated with airway devices in critical care: a review of reports to the UK National Patient Safety Agency

Abstract: We used key words and letter sequences to identify airway-associated patient safety incidents submitted to the UK National Patient Safety Agency from critical care units in England and Wales. We identified 1085 such airway incidents submitted in the two years from October 2005 to September 2007. Three hundred and twelve incidents (28.8%) involved neonates or babies. Of the total 1085 incidents, 200 (18.4%) were associated with tracheal intubation, 53 (4.9%) with tracheostomy and 893 (82.3%) were post-procedure problems. One hundred and ten incidents (10.1%) were associated with more than temporary harm. Eighty-eight intubation incidents were associated with equipment problems. Partial displacement of tubes resulted in more than temporary harm to the patient more frequently than complete tube displacement (15.7% vs 3.8%). Capnography was not described in any cases of displacement or blockage of tracheal or tracheostomy tubes. Recommendations concerning minimum standards for capnography, availability and checking of equipment and tracheostomy placement are made.

Comparison of the Glidescope, the McGrath, the Airtraq and the Macintosh laryngoscopes in simulated difficult airways*.

Abstract: Summary Several indirect laryngoscopes have recently been developed, but relatively few have been formally compared. In this study we evaluated the efficacy and the usability of the Macintosh, the Glidescope � , the McGrathand the Airtraqlaryngoscopes. Sixty anaesthesia providers (20 staff, 20 residents, and 20 nurses) were enrolled into this study. The volunteers intubated the trachea of a Laerdal SimManmanikin in three simulated difficult airway scenarios. In all scenarios, indirect laryngoscopes provided better laryngeal exposure than the Macintosh blade and appeared to produce less dental trauma. In the most difficult scenario (tongue oedema), the Macintosh blade was associated with a high rate of failure and prolonged intubation times whereas indirect laryngoscopes improved intubation time and rarely failed. Indirect laryngoscopes were judged easier to use than the Macintosh. Differences existed between indirect devices. The Airtraq � consistently provided the most rapid intubation. Laryngeal grade views were superior with the Airtraqand McGraththan with the Glidescope � .

Peri‐operative anaesthetic management of cytoreductive surgery with hyperthermic intraperitoneal chemotherapy

Abstract: Cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (HIPEC) is a long and complex procedure with significant blood and fluid loss during debulking and important pathophysiological alterations during the HIPEC phase. We performed a retrospective analysis of 78 consecutive patients undergoing cytoreductive surgery with HIPEC at a university hospital. Our data demonstrate large intra-operative fluid turnover, with 51% of patients requiring a blood transfusion. During HIPEC, airway pressure and central venous pressure increased with a lower oxygenation ratio as a result of increased intra-abdominal pressure with the closed abdomen technique. As a consequence of the raised body temperature, heart rate, end tidal carbon dioxide and arterial lactate levels increased with a slight metabolic acidosis. Peri-operative analysis of routine clotting parameters revealed disturbances of the coagulation status. For pain management, 72% of patients received supplementary thoracic epidural analgesia with consequential peri-operative opioid sparing and a reduced duration of postoperative ventilation.

A meta‐analysis of the utility of pre‐operative brain natriuretic peptide in predicting early and intermediate‐term mortality and major adverse cardiac events in vascular surgical patients

Abstract: We conducted a meta-analysis of the utility of pre-operative B-type natriuretic peptide (BNP) and N-terminal-pro B-type natriuretic peptide in predicting early (< 30 days) and intermediate (< 180 days) term mortality and major adverse cardiac events (cardiac death and nonfatal myocardial infarction) in patients following vascular surgery. A Pubmed Central and EMBASE search was conducted up to January 2008. Of 81 studies identified, seven prospective observational studies were included in the meta-analysis representing five patient cohorts: early outcomes (504 patients) and intermediate-term outcomes (623 patients). A B-type natriuretic peptide or N-terminal-pro B-type natriuretic peptide above the optimal discriminatory threshold determined by receiver operating characteristic curve analysis was associated with 30-day cardiac death (OR 7.6, 95% CI 1.33-43.4, p = 0.02), nonfatal myocardial infarction (OR 6.24, 95% CI 1.82-21.4, p = 0.004) and major adverse cardiac events (OR 17.37, 95% CI 3.31-91.15, p = 0.0007), and intermediate-term, all-cause mortality (OR 3.1, 95% CI 1.85-5.2, p < 0.0001), nonfatal myocardial infarction (OR 2.95, 95% CI 1.17-7.46, p = 0.02) and major adverse cardiac events (OR 3.31, 95% CI 2.1-5.24, p < 0.00001). B-type natriuretic peptide and N-terminal-pro B-type natriuretic peptide are potentially useful pre-operative prognostic tests in vascular surgical patients.

Performance of oxygen delivery devices when the breathing pattern of respiratory failure is simulated

Abstract: Oxygen is the commonest drug prescribed in hospitals The inhaled concentration is altered by the administered oxygen flow rate, the characteristics of the delivery device and the patient's respiratory pattern Using healthy volunteers we measured the inspired oxygen concentration achieved with different devices both at rest and when the breathing pattern of respiratory failure was simulated by binding the subjects' chests until the forced expiratory volume in 1 s was reduced by > 50% and the respiratory rate was > 25 breathsmin(-1) With this respiratory pattern, there was a statistically significant fall in F(I)o(2) while administering oxygen via a Hudson mask at 4 lmin(-1) (238% (95% CI 174-303%) reduction), 12 lmin(-1), humidified (178% (95% CI 88-267%) reduction) and 24 lmin(-1), humidified (122% (95% CI 50-193%) reduction) There was no statistically significant change with a nonrebreathing (reservoir) mask at 15 and 110 lmin(-1) or with a Vapotherm 2000i at 40 lmin(-1), humidified, via nasal prongs We conclude that the F(I)o(2) delivered by high flow devices is unaffected when the breathing pattern of respiratory failure is simulated The F(I)o(2) achieved at rest by a nonrebreathing mask (068) is less than that often quoted in the literature

I‐gel insertion by novices in manikins and patients*

Abstract: Summary The i-gel, a novel supraglottic airway, has been proposed for use during cardiopulmonary resuscitation. We evaluated the performance of this device in manikins and anaesthetised patients when used by novices: medical students, non-anaesthetist physicians and allied health professionals all unfamiliar with the i-gel. Fifty i-gels were placed in manikins. Eighty-eight percent (44/50) were placed on the first attempt with a median insertion time of 14 s (range 7–45). I-gels were placed in 40 healthy anaesthetised patients. Success on the first attempt was 82.5% (33/40) and on the second attempt 15% (6/40). After three attempts there were no failures. Median insertion time was 17.5 s (range 7–197). Median airway seal was 20 cmH2O (range 13–40). One case of regurgitation and partial aspiration occurred. Our results suggest the i-gel is rapidly inserted in both manikins and patients by novice users and compares favourably to other supraglottic airways available. Further work determining safety and efficacy during cardiopulmonary resuscitation is required.

Unanticipated difficult airway management in anaesthetised patients: a prospective study of the effect of mannequin training on management strategies and skill retention

Abstract: This prospective study on a medium-fidelity simulator (SimMan, Laerdal Medical Corporation, Wappingers Falls, NY, USA) examined the management of unanticipated difficult airway by 21 anaesthetists and the effect of training in this context. There were two scenarios investigated: 'cannot intubate, can ventilate' (CI) and 'cannot intubate, cannot ventilate' (CICV). Following initial evaluation, volunteers underwent training in the 'Difficult Airway Society' (DAS) algorithms and associated technical skills. At 6-8 weeks and 6-8 months, performance was compared with the initial evaluation. There was a more structured approach following training (p < 0.05), which was sustained at 6-8 months, but only for the CICV scenario (p < 0.01). In CI, use of standard and intubating laryngeal mask airway increased following training (p = 0.021). This was sustained over time (p = 0.01). In both scenarios there was a reduced incidence of equipment misuse (p < 0.0005), which was sustained over time (p < 0.0001). We conclude that simulation-based training significantly improves performance for at least 6-8 weeks. Training should be repeated at intervals of 6 months or less.

Substrate mobilisation during surgery. A comparison between halothane and fentanyl anaesthesia.

Abstract: A study was undertaken in twenty-eight patients to compare the effects of the supplementation of nitrous oxide and oxygen anaesthesia with either 0.5--1.0% halothane or 50 microgram fentanyl/kg on the metabolic and hormonal response to gynaecological surgery. The results showed that the increases in blood glucose, plasma cortisol and growth hormone concentrations observed in the halothane group of patients were abolished in those who received fentanyl. It is postulated that the ability of large doses of fentanyl to inhibit the cortisol and growth hormone response to surgery may be of value in ameliorating the catabolic response to trauma.

Randomised double-blinded comparison of phenylephrine vs ephedrine for maintaining blood pressure during spinal anaesthesia for non-elective Caesarean section*

Abstract: SUMMARY In a randomised, double-blinded study, we compared boluses of phenylephrine 100 microg with ephedrine 10 mg for treating hypotension (systolic blood pressure < 100 mmHg) in 204 patients having non-elective Caesarean section under spinal anaesthesia. Umbilical arterial (UA) and venous (UV) pH and base excess were similar between groups. In the ephedrine group, UA lactate concentration was higher (median 2.6 [interquartile range 2.3-3.3] vs 2.4 [1.9-3.0] mmolxl(-1), p = 0.002) and UV lactate concentration was higher (2.5 [2.2-3.2] vs 2.3 [1.9-2.8] mmolxl(-1), p = 0.016) and more patients had nausea or vomiting (12.7% vs 3.9%, p = 0.02). Clinical neonatal outcome was similar. Of the protocol-compliant patients (n = 148), UA Po(2) and UV Po(2) were lower in the phenylephrine group although oxygen content was similar. We conclude that phenylephrine and ephedrine are both suitable vasopressors for use in non-elective Caesarean sections.

The Pentax-AWS® rigid indirect video laryngoscope : clinical assessment of performance in 320 cases

Abstract: The Pentax-AWS airway scope system is a rigid indirect video laryngoscope with integrated tube guidance. Laryngoscopy and intubation are visualised using a built in LCD monitor which displays the view obtained by a CCD camera mounted in the tip of the laryngoscope. We describe its clinical performance in 320 patients. The Pentax-AWS significantly improved the laryngeal view compared to the Macintosh laryngoscope. Forty-six patients (14%) who were classified as Cormack Lehane glottic view grade 3 or 4 using the Macintosh laryngoscope were classified as grade 1 (45 cases) or 2a (1 case) using the Pentax-AWS airway scope. Laryngeal views measured by percentage of glottic opening score were improved significantly using the Pentax-AWS. Intubation using the Pentax-AWS was successful in all cases, 96% at the first and 4% at the second attempt. The mean (SD) time required to place the tracheal tube was 20 (10) s. The Cormack Lehane grade obtained with the Macintosh blade did not affect the total time to correctly position the tube using the Pentax-AWS. Intubation difficulty scale (score = 0 in 305 patients, score = 1 in 14 and score = 2 in one patient) indicates that tracheal intubation was performed easily in most cases. The Pentax-AWS not only improves the laryngeal view, but its tube guide also facilitates rapid, easy and reliable tracheal intubation under vision. It can be useful in routine anesthesia care and may be advantageous in the situation of unanticipated difficult intubation.

The use of the BERCI DCI® Video Laryngoscope for teaching novices direct laryngoscopy and tracheal intubation*

Abstract: Traditional teaching of laryngoscopy is difficult due to the trainer and trainee lacking a shared view. The Karl Storz BERCI DCI Video Laryngoscope provides a video image for the trainer and a direct view identical to that of a standard laryngoscope for the trainee. Forty-nine novice subjects were randomly assigned to a control group (n = 24) taught using a standard Macintosh laryngoscope or a study group (n = 25) taught using the Video Laryngoscope. Following training all subjects were assessed using a standard laryngoscope. Under simulated difficult airway conditions the study group performed better in terms of number of attempts (p = 0.02), number of repositioning manoeuvres required (p = 0.046) and teeth trauma (p = 0.034). The study group were more confident of the success of their tube placement (p = 0.035), found it easier than the control group (p = 0.042) and had improved knowledge of airway anatomy (p = 0.011). We conclude that video laryngoscopy confers benefits in the teaching of tracheal intubation.

Safety in anaesthesia: a study of 12,606 reported incidents from the UK National Reporting and Learning System.

Abstract: The incident reporting database at the National Patient Safety Agency was interrogated on the nature, frequency and severity of incidents related to anaesthesia. Of 12,606 reports over a 2-year period, 2842 (22.5%) resulted in little harm or a moderate degree of harm, and 269 (2.1%) resulted in severe harm or death, with procedure or treatment problems generating the highest risk. One thousand and thirty-five incidents (8%) related to pre-operative assessment, with harm occurring in 275 (26.6%), and 552 (4.4%) related to epidural anaesthesia, with harm reported in 198 (35.9%). Fifty-eight occurrences of anaesthetic awareness were also examined. This preliminary analysis is not authoritative enough to warrant widespread changes of practice, but justifies future collaborative approaches to reduce the potential for harm and improve the submission, collection and analysis of incident reports. Practitioners, departments and professional bodies should consider how the information can be used to promote patient safety and their own defensibility.

Use of a leucocyte filter to remove tumour cells from intra-operative cell salvage blood.

Abstract: Summary The intra-operative blood loss of 50 consecutive gynae-oncology patients undergoing surgery for endometrial, cervical or ovarian cancer was cell salvaged and filtered. In each case blood samples were taken from the effluent tumour vein, a central venous line, the cell saver reservoir, the cell salvage re-transfusion bag after processing but before filtration and from the cell salvage re-transfusion bag after processing and filtration. Samples were examined using immunohistochemical monoclonal antibody markers for epithelial cell lines. Viable, nucleated malignant cells were detected in 2/50 central venous samples, 34/50 reservoir samples and 31/50 unfiltered cell salvaged samples. After passage through a Pall RS leucocyte depletion filter no remaining viable, nucleated malignant cells were detected in any sample. The clinical risks of cell salvage in these circumstances should be reviewed in the light of the risks of allogeneic blood transfusion.

Could ‘safe practice’ be compromising safe practice? Should anaesthetists have to demonstrate that face mask ventilation is possible before giving a neuromuscular blocker?

Abstract: A common instruction to trainee anaesthetists in the UK is that they should establish that face mask ventilation (FMV) is possible, before administering neuromuscular blocking drugs (NMBs). As far as we know the ‘no NMBs until FMV has been demonstrated’ rule is not evidence-based. The earliest reference to this policy we have found is in the chapter on tracheal intubation by Professors Gal and White in the third edition of the textbook Anesthesia [1]. Professor Gal has told us that they did not base their recommendation on published work, and did not intend to make failed FMV an absolute contraindication to NMBs (Gal TH, personal communication, 2007). Nevertheless, this policy seems to have become firmly entrenched in the minds of our trainees. This is curious, since it is barely mentioned in two standard UK texts on anaesthesia [2, 3], not mentioned in one other text [4], nor in texts dealing with airway management [5, 6]. Kheterpal and colleagues have reported recently on a study of 22 660 attempts at FMV [7], and their results suggest to us that it is time that the anaesthetic community discussed this issue. At first sight the ‘no NMB before FMV’ rule seems an admirably sensible concept, but we perceive at least five possible defects. Firstly, the theoretical advantage of the rule is not fulfilled in practice. Our trainees tell us that the advantage conferred is that a patient in whom FMV is impossible after induction can be woken up and an alternative technique applied. However, in real life this does not appear to be what happens. In both Kheterpal et al.’s study [7] and a previous, smaller one by Langeron et al. [8], no patient was woken. It may be that when a patient has an obstructed airway it is not feasible to await awakening; something has to be done to ventilate the lungs before catastrophic desaturation occurs. This is a different scenario to that obtaining after failed intubation when oxygenation can be performed by FMV. It is interesting that considerable attention has been given to the development of algorithms to aid the anaesthetist in decision making after failed intubation, but not to what the response to difficulty with mask ventilation before an attempt at intubation should be. Secondly, it to some extent places anaesthetists on the horns of a dilemma. On the one hand enough anaesthetic must be given to permit FMV, but on the other hand the dose must allow a reasonably rapid return of consciousness should FMV prove impossible. It is conceivable that suspicion that a patient may need to be woken up might lead to under-dosing with induction agents, which could of itself result in difficulty with FMV due to an insufficient depth of anaesthesia. We have no evidence that the existence of the ‘no NMB before FMV’ rule leads anaesthetists to underdose patients, but it is possible that the existence of the rule might lead an inexperienced anaesthetist to be fearful of administering adequate doses at induction. In our experience, more difficulty with FMV is encountered when the patient is too lightly anaesthetised than when too deeply anaesthetised. Thirdly, it is our experience that in patients in whom FMV is initially awkward, FMV becomes easier once the NMB has been given. While it might be claimed that this observation is related to the deepening of anaesthesia after induction, rather than to the developing neuromuscular blockade itself, our view is supported (albeit anecdotally) by the observation that this improvement in ease of FMV seems to be related to the speed of onset of the NMB used. We do accept, though, that our claim is difficult to support with evidence, partly because of the difficulty of translating the ‘feel’ of the reservoir bag during FMV into an objective measurement [9]. So our suspicion is that trainees’ reluctance to give a NMB in case FMV proves to be difficult is more likely to result in FMV that is difficult, compounding any difficulty resulting from a relatively low dose of induction agent. Fourthly, should difficulty occur then the absence of neuromuscular blockade may hinder rescue of the situation. In the report by Kheterpal et al. of 22 660 attempts at FMV [7], there were 313 patients in whom FMV was difficult (1.4%), and 37 in whom it was impossible (0.16%). Of the latter 37, tracheal intubation after direct laryngoscopy was successfully performed in 36 (10 were noted to have been ‘difficult’ intubations) and one patient required surgical cricothyrotomy. All 37 were given NMBs, either before FMV was found to be impossible or to aid intubation [10]. In an earlier study by Langeron et al. of 1500 patients, FMV was reported as difficult in 75 (5%) and impossible in one (0.07%) [8]. One can only speculate on the likely success of rescue techniques such as tracheal intubation in the absence of NMBs, in such cases. There is a considerable body of evidence to support the proposition that NMBs make intubation easier [11–14]. A conclusion that could be drawn from Kheterpal et al.’s report is that, if tracheal intubation is planned in a patient in whom difficulty with FMV is a possibility, the safest tactic is to give NMB drugs as soon as possible, so that conditions for intubation are optimised. A logical extension of this is to suggest that since not all such patients can be identified in advance, NMBs should be given routinely immediately after induction. Fifthly, the rule might inhibit practitioners in situations where FMV is Anaesthesia, 2008, 63, pages 113–115 .....................................................................................................................................................................................................................

Auricular acupuncture for postoperative pain control: a systematic review of randomised clinical trials.

Abstract: The number of publications on the peri-operative use of auricular acupuncture has rapidly increased within the last decade. The aim was to evaluate clinical evidence on the efficacy of auricular acupuncture for postoperative pain control. Electronic databases: Medline, MedPilot, DARE, Clinical Resource, Scopus and Biological Abstracts were searched from their inception to September 2007. All randomised clinical trials on the treatment of postoperative pain with auricular acupuncture were considered and their quality was evaluated using the Jadad scale. Pain intensity and analgesic requirements were defined as the primary outcome measures. Of 23 articles, nine fulfilled the inclusion criteria. Meta-analytic approach was not possible because of the heterogeneity of the primary studies. In eight of the trials, auricular acupuncture was superior to control conditions. Seven randomised clinical trials scored three or more points on the Jadad scale but none of them reached the maximum of 5 points. The evidence that auricular acupuncture reduces postoperative pain is promising but not compelling.

Epidural lidocaine-bicarbonate-adrenaline vs levobupivacaine for emergency Caesarean section: a randomised controlled trial.

Abstract: Epidural mixtures containing lidocaine with or without additives are commonly used to convert epidural analgesia in labour to anaesthesia for emergency Caesarean section, but direct comparisons with alternative, single agents in this situation are few. In a prospective double-blinded trial, we compared a freshly prepared lidocaine-bicarbonate-adrenaline mixture (final concentrations 1.8%, 0.76% and 1:200,000, respectively) with our standard agent, levobupivacaine 0.5%, for extending epidural blockade for emergency Caesarean section. Using a sequential analysis technique, with data analysed in blocks of 40, women receiving epidural analgesia in labour who required top-up for Caesarean section were randomly assigned to receive 20 ml of epidural solution over 3 min. The first analysis (n = 40) indicated that the study should be stopped, as significant differences were found in our primary outcome data. Median (IQR [range]) times to reach a block to touch to T5 and cold to T4 were, respectively, 7 (6-9 [5-17]) min and 7 (5-8 [4-17]) min for lidocaine-bicarbonate-adrenaline, and 14 (10 -17 [9-31]) min and 11 (9-14 [6-30]) min for levobupivacaine (p = 0.00004 and 0.001, respectively). Pre- and intra-operative supplementation/pain, maternal side-effects and neonatal outcomes (excluding five women who underwent instrumental delivery) were similar between the groups. Intra-operative maternal sedation (scored by the mother on a 10-point scale) was greater with lidocaine-bicarbonate-adrenaline (4.5 (3-8 [1-9])) than with levobupivacaine (3 (1-4 [1-7])), but not significantly so (p = 0.07). We conclude that epidural lidocaine-bicarbonate-adrenaline halves the onset time when extending epidural analgesia for Caesarean section although there is a possibility of increased maternal sedation.

A comparison of cervical spine movement during laryngoscopy using the Airtraq® or Macintosh laryngoscopes*

Abstract: Summary The Airtraq® laryngoscope has an oropharyngeal airway-shaped blade that provides a non-line-of-sight view of the glottis. The configuration of the blade should mean that less movement of the cervical spine is required during laryngeal visualisation. We compared the degree of cervical spine movement in laryngoscopy performed using the Airtraq and conventional Macintosh laryngoscope. In 20 patients requiring general anaesthesia and tracheal intubation, we measured cervical spine movement using radiography in the same patient during consecutive procedures using the two laryngoscopes. Although significant movement of the cervical spine from baseline was noted during all procedures (p < 0.05), cervical spinal extension with the Airtraq was 29% less than that measured during Macintosh laryngoscopy between the occiput and C4, and 44% less at the C3/C4 motion segment (p < 0.05). Anterior deviations of the vertebral bodies from baseline were 32%, 35%, 38% and 40% less at the atlas, C2, C3, and C4 vertebrae, respectively, during Airtraq laryngoscopy than those measured during Macintosh laryngoscopy (p < 0.01). Our study demonstrated that laryngoscopy using the Airtraq laryngoscope involves less movement of the cervical spine compared to conventional procedures using a Macintosh laryngoscope.

Cardiac output monitoring: basic science and clinical application.

Abstract: Derangements in the circulation are a common feature of sepsis, trauma, major surgery and other critical illnesses. Detailed evaluation of the circulation is therefore an essential aspect of the clinical management of such patients. The use of cardiac output monitoring technology is an increasingly important aspect of evaluating patients in the operating theatre, critical care unit and elsewhere. There are now a number of different technologies available for this purpose, which use a diverse range of physiological principles. A detailed understanding of the physiological principles applied by such technology is essential for safe and effective use in clinical practice. The aim of this article is to describe the physiological principles used to measure cardiac output and their application in various monitors in common clinical use.

The LMA Supreme--a pilot study.

Abstract: References 1 Sawin PD, Todd MM, Traynelis VC, et al. Cervical spine motion with direct laryngoscopy and orotracheal intubation: an in vivo cinefluoroscopic study of subjects without cervical abnormality. Anesthesiology 1996; 85: 26–36. 2 Lennarson PJ, Smith D, Todd MM, et al. Segmental cervical spine motion during orotracheal intubation of the intact and injured spine with and without external stabilization. Journal of Neurosurgery 2000; 92 (Suppl. 2): 201– 6. 3 Lennarson PJ, Smith DW, Sawin PD, Todd MM, Sato Y, Traynelis VC. Cervical spinal motion during intubation: efficacy of stabilization maneuvers in the setting of complete segmental instability. Journal of Neurosurgery 2001; 94 (Suppl. 2): 265–70. 4 Crosby ET. Airway management in adults after cervical spine trauma. Anesthesiology 2006; 104: 1293– 318.

Metabolic acidosis in the critically ill: part 2. Causes and treatment.

Abstract: The correct identification of the cause, and ideally the individual acid, responsible for metabolic acidosis in the critically ill ensures rational management. In Part 2 of this review, we examine the elevated (corrected) anion gap acidoses (lactic, ketones, uraemic and toxin ingestion) and contrast them with nonelevated conditions (bicarbonate wasting, renal tubular acidoses and iatrogenic hyperchloraemia) using readily available base excess and anion gap techniques. The potentially erroneous interpretation of elevated lactate signifying cell ischaemia is highlighted. We provide diagnostic and therapeutic guidance when faced with a high anion gap acidosis, for example pyroglutamate, in the common clinical scenario 'I can't identify the acid--but I know it's there'. The evidence that metabolic acidosis affects outcomes and thus warrants correction is considered and we provide management guidance including extracorporeal removal and fomepizole therapy.

Effects of fentanyl pretreatment on the QTc interval during propofol induction

Abstract: Prolongation of the corrected QT (QTc) interval is associated with various anaesthetic drugs. The QTc prolongation may become more exacerbated during laryngoscopy and intubation, which is possibly caused by sympathetic stimulation. The aim of this study was to investigate the effects of fentanyl on the QTc interval during propofol induction in healthy patients. The patients were randomly allocated to receive either fentanyl (n = 25) or saline (n = 25) before induction. The QTc interval was significantly prolonged immediately after intubation in control group compared to preceding values, but it did not change in the fentanyl group. The number of patients with the prolonged QTc interval exceeding 20 ms immediately after intubation compared to the baseline values was 14 in the control group and seven in the fentanyl group. In conclusion, pretreatment with fentanyl 2 microg x kg(-1) significantly attenuated QTc prolongation associated with laryngoscopy and tracheal intubation during propofol induction.

Pitfalls of ultrasound guided vascular access: the use of three/four-dimensional ultrasound.

Abstract: The use of ultrasound guidance for central venous access is widespread and was recommended as the technique of choice by The National Institute of Clinical Excellence in the UK in 2002. However, complications have been reported using this technique. In this article we review the technique of two-dimensional ultrasound needle guidance and the errors that can occur. We then discuss the development of three- and four-dimensional ultrasound and describe our experiences using this imaging modality in simulated and actual needle-guidance. We discuss the potential advantages for clinicians utilising this newer form of ultrasound imaging for central venous access.

Medication‐related patient safety incidents in critical care: a review of reports to the UK National Patient Safety Agency*

Abstract: We reviewed all patient safety incidents reported to the UK National Patient Safety Agency between 1st August 2006 and 28th February 2007 from intensive care or high dependency units. Incidents involving medications were then categorised. 12 084 incidents were submitted from 151 organisations (median 40, range 1-634/organisation). 2428 incidents were associated with medication use involving 355 different drugs, most commonly morphine (207 incidents), gentamicin (190 incidents) and noradrenaline (133 incidents). Noradrenaline (55 incidents of harm) and insulin (48 incidents of harm) were most commonly associated with patient harm. Sixty-one percent of medication incidents were associated with drug administration and 26% with prescription. Two hundred and eighty-seven medication incidents caused temporary harm and 43 more than temporary harm. Five per cent of medication incidents were associated with staff communication during transfer from theatre or recovery. Categorisation of medication-associated incidents has allowed us to suggest changes to improve the reporting of incidents and to improve medication safety.