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Wiley Online Library : Anaesthesia
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Issue Information – Editorial Board

19. October 2017 - 5:27
Categories: From Anaesthesia

Onset of labour epidural analgesia with low-dose bupivacaine and different doses of fentanyl

19. October 2017 - 5:27
Summary

This study investigated the effects of different doses of epidural fentanyl on the time to onset of epidural analgesia in women in early labour. We hypothesised that onset of epidural labour analgesia (the primary outcome defined as time in minutes from completion of epidural bolus to the first uterine contraction with a numeric pain rating scale [NPRS] score ≤ 3) would be faster with 100 μg of fentanyl epidural bolus compared with 20 μg or 50 μg. Epidural labour analgesia was initiated with 20 μg of fentanyl (F20 group), 50 μg (F50 group) or 100 μg (F100 group) along with 10 ml bupivacaine 0.08% as the loading dose. We randomly allocated 105 patients, with 35 patients in each group. Median (IQR [range]) time to achieve NPRS ≤ 3 was 18 (11–30 [6–20]) min in F20, 10 (8–19 [4–30]) min in F50 and 10 (6–16 [3–30]) min in F100 groups. There was a significant difference in onset times comparing F100 with F20 (p < 0.001) and F50 with F20 (p = 0.007), but not significantly different comparing F100 with F50 (p = 0.19). The median (IQR [range]) time from the epidural loading dose to first patient controlled epidural analgesia bolus was 61 min (20–165 [20–420]) in F20, 118 min (66–176 [20–396]) in F50 and 150 min (66–214 [30-764]) in F100 groups. This was not statistically significant (p = 0.16) comparing the F20 with the F100 group. There were no significant differences in maternal side-effects, mode of delivery, patient satisfaction scores or neonatal Apgar scores between all groups. We conclude that the 50 μg and 100 μg fentanyl doses were associated with reduced onset times to effective analgesia compared with the 20 μg dose.

Categories: From Anaesthesia

Hyperbaric vs. isobaric bupivacaine for spinal anaesthesia for elective caesarean section: a Cochrane systematic review

17. October 2017 - 6:55
Summary

Both isobaric and hyperbaric bupivacaine have been used for spinal anaesthesia for elective caesarean section, but it is not clear if one is better than the other. The primary objective of this systematic review was to determine the effectiveness and safety of hyperbaric bupivacaine compared with isobaric bupivacaine administered during spinal anaesthesia for elective caesarean section. We included 10 studies with 614 subjects in the analysis. There was no evidence of differences either in the risk of conversion to general anaesthesia, with a relative risk (95%CI) of 0.33 (0.09–1.17) (very low quality of evidence), or in the need for supplemental analgesia, the relative risk (95%CI) being 0.61 (0.26–1.41) (very low quality of evidence). There was also no evidence of a difference in the use of ephedrine, the amount of ephedrine used, nausea and vomiting, or headache. Hyperbaric bupivacaine took less time to reach a sensory block height of T4, with a mean difference (95%CI) of −1.06 min (−1.80 to −0.31). Due to the rarity of some outcomes, dose variability, use of adjuvant drugs and spinal technique used, future clinical trials should look into using adequate sample size to investigate the primary outcome of the need for supplemental analgesia.

Categories: From Anaesthesia

Publisher's Note

16. October 2017 - 8:46
Categories: From Anaesthesia

Nitrous oxide-based vs. nitrous oxide-free general anaesthesia and accidental awareness in surgical patients: an abridged Cochrane systematic review

16. October 2017 - 7:25
Summary

Accidental awareness during general anaesthesia can arise from a failure to deliver sufficient anaesthetic agent, or from a patient's resistance to an expected sufficient dose of such an agent. Awareness is ‘explicit’ if the patient is subsequently able to recall the event. We conducted a systematic review into the effect of nitrous oxide used as part of a general anaesthetic on the risk of accidental awareness in people over the age of five years undergoing general anaesthesia for surgery. We included 15 randomised controlled trials, 14 of which, representing a total of 3439 participants, were included in our primary analysis of the frequency of accidental awareness events. The awareness incidence rate was rare within these studies, and all were considered underpowered with respect to this outcome. The risk of bias across all studies was judged to be high, and 76% of studies failed adequately to conceal participant allocation. We considered the available evidence to be of very poor quality. There were a total of three accidental awareness events reported in two studies, one of which reported that the awareness was the result of a kink in a propofol intravenous line. There were insufficient data to conduct a meta- or sub-group analysis and there was insufficient evidence to draw outcome-related conclusions. We can, however, recommend that future studies focus on potentially high-risk groups such as obstetric or cardiac surgery patients, or those receiving neuromuscular blocking drugs or total intravenous anaesthesia.

Categories: From Anaesthesia

Real-time ultrasound-guided axillary vein cannulation in children: a randomised controlled trial

9. October 2017 - 5:29
Summary

The axillary vein is a good site for ultrasound-guided central venous cannulation in terms of infection rate, patient comfort and its anatomical relationship with the clavicle and lungs. We compared real-time ultrasound-guided axillary vein cannulation with conventional infraclavicular landmark-guided subclavian vein cannulation in children. A total of 132 paediatric patients were randomly allocated to either ultrasound-guided axillary vein (axillary group) or landmark-guided subclavian vein (landmark group). The outcomes measured were success rate after two attempts, first-attempt success rate, time to cannulation and complication rate. The success rate after two attempts was 83% in the axillary group compared with 63% in the landmark group (odds ratio 2.85, 95%CI 1.25–6.48, p = 0.010). The first-attempt success rate was 46% for the axillary group and 40% for the landmark group (p = 0.274) and median time to cannulation was 156 s for the axillary group and 180 s for the landmark group (p = 0.286). There were no differences in complication rates between the two groups, although three episodes of subclavian artery puncture occurred in the landmark group (p = 0.08). We conclude that axillary vein cannulation using a real-time ultrasound-guided in-plane technique is useful and effective in paediatric patients.

Categories: From Anaesthesia

Can point-of-care ultrasound predict spinal hypotension during caesarean section? A prospective observational study

7. October 2017 - 6:20
Summary

Spinal anaesthesia for elective caesarean section is associated with maternal hypotension, secondary to alteration of sympathetic tone and hypovolemia, in up to 70% of cases. Measurement of the subaortic variation in the velocity time integral (VTI) after passive leg raising allows prediction of fluid responsiveness. Our objective, in this prospective single-centre observational study, was to assess the ability of change in VTI after 45° passive leg raising to predict hypotension after spinal anaesthesia. Ultrasound measurements were performed just before elective caesarean section. Anaesthesia, intravenous coloading and prophylactic vasopressor treatment were standardised according to current guidelines. We studied 40 women. Hypotension occurred in 17 (45%) women. The area (95%CI) under the receiver operating characteristics (ROC) curve for the prediction of spinal hypotension was 0.8 (0.6–0.9; p = 0.0001). Seventeen women had a change in VTI with leg elevation ≤ 8%, which was predictive for not developing hypotension, and 11 had a change ≥ 21%, predictive for hypotension. The grey zone between 8% and 21%, with inconclusive values, included 12 women. We suggest that cardiac ultrasound provides characterisation of the risk of hypotension following spinal anaesthesia at elective caesarean section, and therefore may allow individualised strategies for prevention and management.

Categories: From Anaesthesia

Dynamic ultrasound-guided short-axis needle tip navigation technique vs. landmark technique for difficult saphenous vein access in children: a randomised study

6. October 2017 - 5:00
Summary

Dynamic ultrasound-guided short-axis needle tip navigation is a novel technique for vascular access. After venipuncture, the needle and catheter are further advanced within the vessel lumen under real-time ultrasound guidance with constant visualisation of the needle tip in the short-axis view. This can minimise the risk of transfixing the cannulated vessel. We compared two techniques for non-visible saphenous vein cannulation under general anaesthesia in children weighing ≥ 3 kg and less than four years of age: dynamic ultrasound-guided short-axis needle tip navigation technique (ultrasound group) vs. landmark technique. Venous cannulation was performed by three experienced anaesthetists. The primary outcome measure was first-attempt success rate. Success rate within 10 min was a secondary outcome. A total of 102 patients were randomly allocated to either the ultrasound group or the landmark group. First-attempt success rate was 90% in the ultrasound group compared with 51% in the landmark group, p<0.001, difference 39%, 95% confidence interval (CI) of the difference 23–55%. Success rate within 10 min was 92% in the ultrasound group compared with 63% in the landmark group, p = 0.001, difference 29%, 95%CI of the difference 14–45%. We conclude that, when performed by experienced anaesthetists, the dynamic ultrasound-guided short-axis needle tip navigation technique improved non-visible saphenous vein cannulation in children compared with the landmark technique.

Categories: From Anaesthesia

Pre-operative variables including fitness associated with complications after oesophagectomy

6. October 2017 - 4:20
Summary

Oesophagectomy is a technically-demanding operation associated with a high level of morbidity. We analysed the association of pre-operative variables, including those from cardiopulmonary exercise testing, with complications (logistic regression) and survival and length of stay (Cox regression) after scheduled transthoracic oesophagectomy in 273 adults, in isolation and on multivariate testing (maximum Akaike information criterion). On multivariate analysis, any postoperative complication was associated with ventilatory equivalents for carbon dioxide, odds ratio (95%CI) 1.088 (1.02–1.17), p = 0.018. Cardiorespiratory complications were associated with FEV1 and pre-operative background survival (in an analogous group without cancer), odds ratios (95%CI) 0.55 (0.37–0.80), p = 0.002 and 0.89 (0.82–0.96), p = 0.004, respectively. Survival was associated with the ratio of expected-to-observed ventilatory equivalents for carbon dioxide and predicted postoperative survival, hazard ratios (95%CI) 0.17 (0.03–0.91), p = 0.039 and 0.96 (0.90–1.01), p = 0.076. Length of hospital stay was associated with FVC, hazard ratio (95%CI) 1.38 (1.17–1.63), p < 0.0001.

Categories: From Anaesthesia

A retrospective study of ketamine administration and the development of acute or post-traumatic stress disorder in 274 war-wounded soldiers

3. October 2017 - 10:05
Summary

The objective of this study was to explore whether ketamine prevents or exacerbates acute or post-traumatic stress disorders in military trauma patients. We conducted a retrospective study of a database from the French Military Health Service, including all soldiers surviving a war injury in Afghanistan (2010–2012). The diagnosis of post-traumatic stress disorder was made by a psychiatrist and patients were analysed according to the presence or absence of this condition. Analysis included the following covariables: age; sex; acute stress disorder; blast injury; associated fatality; brain injury; traumatic amputation; Glasgow coma scale; injury severity score; administered drugs; number of surgical procedures; physical, neurosensory or aesthetic sequelae; and the development chronic pain. Covariables related to post-traumatic and acute stress disorders with a p ≤ 0.10 were included in a multivariable logistic regression model. The data from 450 soldiers were identified; 399 survived, of which 274 were analysed. Among these, 98 (36%) suffered from post-traumatic stress disorder and 89 (32%) had received ketamine. Fifty-four patients (55%) in the post-traumatic stress disorder group received ketamine vs. 35 (20%) in the no PTSD group (p < 0.001). The 89 injured soldiers who received ketamine had a median (IQR [range]) injury severity score of 5 (3–13 [1–26]) vs. 3 (2–4 [1–6] in the 185 patients who did not (p < 0.001). At multivariable analysis, only acute stress disorder and total number of surgical procedures were independently associated with the development of post-traumatic stress disorder. In this retrospective study, ketamine administration was not a risk factor for the development of post-traumatic stress disorder in the military trauma setting.

Categories: From Anaesthesia

Continuous infusion vs. intermittent bolus injection of furosemide in acute decompensated heart failure: systematic review and meta-analysis of randomised controlled trials

22. September 2017 - 7:35
Summary

Loop diuretics remain a fundamental pharmacological therapy to remove excess fluid and improve symptom control in acute decompensated heart failure. Several recent randomised controlled trials have examined the clinical benefit of continuous vs. bolus furosemide in acute decompensated heart failure, but have reported conflicting findings. The aim of this review was to compare the effects of continuous and bolus furosemide with regard to mortality, length of hospital stay and its efficacy profile in acute decompensated heart failure. All parallel-arm randomised controlled trials from MEDLINE, EMBASE, PubMed and the Cochrane Database of Systematic Reviews from inception until May 2017 were included. Cross-over randomised controlled trials, observational studies, case reports, case series and non-systematic reviews that involved children were excluded. Eight trials (n = 669) were eligible for inclusion. There was no difference between furosemide continuous infusion and bolus administration for all-cause mortality (four studies; n = 491; I2 = 0%; OR 1.65; 95%CI 0.93–2.91; p = 0.08) or duration of hospitalisation (six studies; n = 576; I2 = 71%; mean difference 0.27; 95%CI −1.35 to 1.89 days; p = 0.74). Continuous infusion of intravenous furosemide was associated with increased weight reduction (five studies; n = 516; I2 = 0%; mean difference 0.70; 95%CI 0.12–1.28 kg; p = 0.02); increased total urine output in 24 h (four studies; n = 390; I2 = 33%; mean difference 461.5; 95%CI 133.7–789.4 ml; p < 0.01); and reduced brain natriuretic peptide (two studies; n = 390; I2 = 0%; mean difference 399.5; 95%CI 152.7–646.3 ng.l−1; p < 0.01), compared with the bolus group. There was no difference in the incidence of raised creatinine and hypokalaemia between the two groups. In summary, there was no difference between continuous infusion and bolus of furosemide for all-cause mortality, length of hospital stay and electrolyte disturbance, but continuous infusion was superior to bolus administration with regard to diuretic effect and reduction in brain natriuretic peptide.

Categories: From Anaesthesia

Videolaryngoscopy vs. direct laryngoscopy use by experienced anaesthetists in patients with known difficult airways: a systematic review and meta-analysis

22. September 2017 - 7:25
Summary

Experienced anaesthetists can be confronted with difficult or failed tracheal intubations. We performed a systematic review and meta-analysis to ascertain if the literature indicated if videolaryngoscopy conferred an advantage when used by experienced anaesthetists managing patients with a known difficult airway. We searched PubMed, MEDLINE, Embase and the Cochrane central register of controlled trials up to 1 January 2017. Outcome parameters extracted from studies were: first-attempt success of tracheal intubation; time to successful intubation; number of intubation attempts; Cormack and Lehane grade; use of airway adjuncts (e.g. stylet, gum elastic bougie); and complications (e.g. mucosal and dental trauma). Nine studies, including 1329 patients, fulfilled the inclusion criteria. First-attempt success was greater for all videolaryngoscopes (OR 0.34 (95%CI 0.18–0.66); p = 0.001). Use of videolaryngoscopy was associated with a significantly better view of the glottis (Cormack and Lehane grades 1 and 2 vs. 3–4, OR 0.04 (95%CI 0.01–0.15); p < 0.00001). Mucosal trauma occurred less with the use of videolaryngoscopy (OR 0.16 (95%CI 0.04–0.75); p = 0.02). Videolaryngoscopy has added value for the experienced anaesthetist, improving first-time success, the view of the glottis and reducing mucosal trauma.

Categories: From Anaesthesia