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  • The obstetric RSI.

    24 October 2018

  • Interpretations of responses using the isolated forearm technique in general anaesthesia: a debate.

    24 October 2018

    The isolated forearm technique (IFT) enables an otherwise paralysed patient to communicate awareness to the anaesthetist. We present a debate that focuses on how best to interpret IFT responses. On one side, Pandit argues that there is a range of response types from none through to movement initiated by the patient to alert the researcher. He also presents a de novo numerical scale by which IFT responses could be classed. Each response type reflects the underlying mental state (degree of unconsciousness), and he concludes that the effect of general anaesthesia on patients is not binary but heterogeneous. There can be mental states resulting from anaesthesia that produce adequate levels of conscious impairment sufficient for surgery to proceed, but in which a degree of wakefulness, including a capacity for later recall, is retained (a state previously termed 'dysanaesthesia'). A literature review of IFT (31 trials) is presented to support this assertion. In rebuttal, Russell and Wang argue that IFT response types are not so discrete, and that the IFT technique precludes higher levels of response. They argue that overinterpretation of IFT responses might in fact result in a greater risk of accidental awareness; a binary interpretation of the IFT response is the safest option. All authors agree that the IFT has a role in clinical practice and the study of anaesthetic mechanisms.

  • Calculating the probability of random sampling for continuous variables in submitted or published randomised controlled trials.

    24 October 2018

    In a previous paper, one of the authors (JBC) used a chi-squared method to analyse the means (SD) of baseline variables, such as height or weight, from randomised controlled trials by Fujii et al., concluding that the probabilities that the reported distributions arose by chance were infinitesimally small. Subsequent testing of that chi-squared method, using simulation, suggested that the method was incorrect. This paper corrects the chi-squared method and tests its performance and the performance of Monte Carlo simulations and ANOVA to analyse the probability of random sampling. The corrected chi-squared method and ANOVA method became inaccurate when applied to means that were reported imprecisely. Monte Carlo simulations confirmed that baseline data from 158 randomised controlled trials by Fujii et al. were different to those from 329 trials published by other authors and that the distribution of Fujii et al.'s data were different to the expected distribution, both p < 10(-16) . The number of Fujii randomised controlled trials with unlikely distributions was less with Monte Carlo simulation than with the 2012 chi-squared method: 102 vs 117 trials with p < 0.05; 60 vs 86 for p < 0.01; 30 vs 56 for p < 0.001; and 12 vs 24 for p < 0.00001, respectively. The Monte Carlo analysis nevertheless confirmed the original conclusion that the distribution of the data presented by Fujii et al. was extremely unlikely to have arisen from observed data. The Monte Carlo analysis may be an appropriate screening tool to check for non-random (i.e. unreliable) data in randomised controlled trials submitted to journals.

  • Peri-operative management of the obese surgical patient 2015: Association of Anaesthetists of Great Britain and Ireland Society for Obesity and Bariatric Anaesthesia.

    24 October 2018

    Guidelines are presented for the organisational and clinical peri-operative management of anaesthesia and surgery for patients who are obese, along with a summary of the problems that obesity may cause peri-operatively. The advice presented is based on previously published advice, clinical studies and expert opinion.

  • No benefit of ultrasound-guided transversus abdominis plane blocks over wound infiltration with local anaesthetic in elective laparoscopic colonic surgery: results of a double-blind randomized controlled trial.

    24 October 2018

    AIM: Advances in laparoscopic techniques combined with enhanced recovery pathways have led to faster recuperation and discharge after colorectal surgery. Peripheral nerve blockade using transversus abdominis plane (TAP) blocks reduce opioid requirements and provide better analgesia for laparoscopic colectomies than do inactive controls. This double-blind randomized study was performed to compare TAP blocks using bupivacaine with standardized wound infiltration with local anaesthetic (LA). METHOD: Seventy-one patients were randomized to receive either TAP block or wound infiltration. The TAP blocks were performed by experienced anaesthetists who used ultrasound guidance to deliver 40 ml of 0.25% bupivacaine post-induction into the transverse abdominis plane. In the control group, 40 ml of 0.25% bupivacaine was injected around the trocar and the extraction site by the surgeon. Both groups received patient-controlled analgesia (PCA) with intravenous morphine. Patients and nursing staff assessed pain scores 6, 12, 24 and 48 h after surgery. The primary outcome was overall morphine use in the first 48 h. RESULTS: Of the 71 patients, 20 underwent a right hemicolectomy and 51 a high anterior resection. The modified intention-to-treat analysis showed no significant differences in overall morphine use [47.3 (36.2-58.5) mg vs 46.7 (36.2-57.3) mg; mean (95% CI), P = 0.8663] in the first 48 h. Pain scores were similar at 6, 12, 24 and 48 h. No differences were found regarding time to mobilization, resumption of diet and length of hospital stay. CONCLUSION: In elective laparoscopic colectomies, standardized wound infiltration with LA has the same analgesic effect as TAP blocks post-induction using bupivacaine at 48 h.