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Consensus statement on fasting before procedural sedation - underestimating the threat to patient safety? The denominator for procedural sedation research should be the actual sedation encounters themselves, and it is not relevant which other patients received general anaesthesia during the same study period. Zdravkovic et al. request that we add to Table 1 a study [10] that was not of procedural sedation, but rather of anaesthetists administering general anaesthesia or "monitored anaesthesia care" (which may at times include, but certainly is not synonymous with, procedural sedation). [Extracted from the article]

The purpose of this study was to evaluate factors influencing the use of propofol-based total intravenous anaesthesia (TIVA)since despite TIVA being a well-established technique, it is used far less frequently than volatile anaesthesia. Questions were formulated after reviewing the literature for perceived disadvantages of TIVA and meeting with a focus group consisting of both senior and junior anaesthestists from our department. Once the survey had been formulated, specialist anaesthetists from professional colleges and societies from several countries were invited to complete the survey on an electronic web-based platform to allow evaluation of the respondent's rating of the importance of a range of factors in their decision not to use TIVA for a particular case. Basic descriptive statistics were determined using SPSS statistical software, while graphical depictions of data were handled using R for statistical analysis. A total of 763 survey responses were included in the final analysis and stratified according to the frequency of TIVA use. Among the infrequent users, issues such as additional effort, institutional preference, lack of real-time monitoring of propofol concentration, risk of missing drug delivery failure and increased turnaround time were among the top reasons mentioned. Interestingly, these issues were considered far less important among the frequent users when not choosing TIVA. We concluded that frequent and infrequent users respond quite differently to similar technical TIVA-related factors. Non-technical factors may play an important role in the infrequent user's decision not to use TIVA for a particular case. [ABSTRACT FROM AUTHOR]

An editorial is presented which discusses guidelines on total intravenous anaesthesia (TIVA). It mentions that TIVA guidelines provide some guidance on target concentrations but emphasise the importance of titration. It states that pre-oxygenation can be achieved safely under light and moderate propofol sedation when cricoid pressure can be applied and the dose increased to loss of consciousness.

Background: Intrathecal morphine pre-conditioning attenuates cardiac ischemia–reperfusion injury via activation of central opioid receptors. We hypothesized that intrathecal morphine also post-conditions the myocardium in the rat. Methods: Intrathecal morphine at 0.3 μg/kg (LMPC), 3 μg/kg (MMPC) or 30 μg/kg (HMPC) was administered for 5 min before 120-min reperfusion following 30-min ischemia. Infarct size as a percentage of area at risk (IS/AAR) was determined using triphenyltetrazolium staining. MMPC was repeated following the intrathecal administration of nor BNI, NTD, CTOP, or naloxone methiodide (NM), kappa, delta, mu and non-specific opioid receptor antagonists, respectively. The role of peripheral opioid, adenosine and calcitonin gene-related peptide (CGRP) receptors was examined by the intravenous administration of NM, 8-ρ-sulfophenyl theophylline (8-SPT) and human CGRP fragment (CGRP8−37), respectively. Results: Morphine post-conditioning at all three doses was cardioprotective (IS/AAR of LMPC=37±4%, MMPC=35±5%, HMPC=32±4%, control=50±5%, P<0.01). The prior administration of opioid receptor antagonists intrathecally, as well as intravenous 8-SPT and CGRP8−37 receptor antagonists, abolished this effect (nor BNI+MMPC=47±7%, NTD+MMPC=49±7%, CTOP+MMPC=45±9%, NM+MMPC=47±6% 8-SPT+MPC=46±5% & CGRP8−37+MPC=53±6%, P=0.63). However, the intravenous administration of NM did not prevent the protective effect (34±4%, P<0.01). Conclusions: Intrathecal morphine administration can induce pharmacological cardiac post-conditioning as it involves opioid receptor centrally but non-opioid receptors peripherally. [ABSTRACT FROM AUTHOR]

Background: Ischemic pre- or post-conditioning of the heart has been shown to involve opioid receptors. Remifentanil, an ultra-short-acting selective mu opioid receptor agonist in clinical use, pre-conditions the rat heart against ischemia-reperfusion injury. This study investigates whether remifentanil post-conditioning is also cardioprotective.Methods: Remifentanil post-conditioning (5-min infusion at 1, 5, 10 or 20 microg/kg/min) or ischemic post-conditioning (three cycles of a 10 s reperfusion interspersed with a 10 s ischemia) was induced in an open-chest rat heart model of ischemia and reperfusion injury, in the presence or absence of nor-binaltorphimine, naltrindole or CTOP, specific kappa, delta and mu opioid receptor antagonists, respectively. The same sequence of experiments was repeated in the isolated heart model using the maximal protective dose of remifentanil from the dose-response studies.Results: Both ischemic and remifentanil post-conditioning reduced the myocardial infarct size relative to the control group in both models. This cardioprotective effect for both post-conditioning regimes was prevented by the prior administration of nor-binaltorphimine and naltrindole but not CTOP. The sole administration of the antagonists had no effect on the size of myocardial infarction.Conclusions: These results indicate that remifentanil post-conditioning protects the heart from ischemia-reperfusion injury to a similar extent as of ischemic post-conditioning. This protection involves kappa and delta but not mu opioid receptor activation. This drug has great potential as a clinical post-conditioning modality as it can be given in large doses without prolonged opioid-related side effects. [ABSTRACT FROM AUTHOR]

Chronic or persistent pain is increasingly recognised as a consequence of surgery in a number of different disciplines. The pain often exhibit qualities that differ from the acute post-operative pain and may represent changes in the central nervous system. There is lack of information regarding the incidence of persistent pain in patients following spinal surgery for scoliosis. This study aims to estimate the incidence of persistent pain following spinal surgery for scoliosis in a group of mainly adolescent patients. Questionnaires were distributed to consecutive patients attending the outpatient clinic of a hospital with specialist services in paediatric orthopaedics and spinal surgery. One hundred and five patients out of 122 eligible patients completed the survey. Fifty-two percent had ongoing pain upon hospital discharge either in the primary surgical site and/or in the iliac bone graft site. Approximately 10 and 7% of all patients had back and pelvic pain persisting beyond 12 months, respectively. A small proportion described elements of neuropathic pain. There was a trend suggesting that those who experienced more severe post-operative pain were more likely to develop persistent pain. These data are consistent with those reports that implicate surgery as the trigger for chronic pain. [ABSTRACT FROM AUTHOR]

A randomised cross-over study was performed in 34 patients with no evidence of airway difficulties, following induction of general anaesthesia, to compare the efficacy of the Levitan FPS scope™ (LFPS) and the single-use bougie for tracheal intubation during simulated grade IIIa laryngoscopy. Success rates for intratracheal placement of the device, and the time required for insertion and tracheal intubation were recorded. Both devices were equally successful (31/34 for the LFPS vs 29/34 for the bougie) for insertion into the glottis. The mean insertion time for the LFPS was statistically longer than that for the bougie (4.4–12.5 s) but this difference was not clinically relevant. Intubation times were similar between the two devices. Major problems hindering successful intubation using the LFPS were the presence of a narrow epiglottic-pharyngeal wall space and copious secretions. An inability to maintain the desired shape was the principal cause of failure with the bougie. [ABSTRACT FROM AUTHOR]

A randomised study was carried out in 60 anaesthetised patients with no evidence of airway difficulties, to compare the Williams Airway Intubator and the Ovassapian Fibreoptic Intubating Airway for bronchoscopic view and ease of railroading a tracheal tube during fibreoptic orotracheal intubation. The Williams Airway Intubator provided a better view of the glottis (41 (68.3%) unobstructed views) than the Ovassapian Fibreoptic Intubating Airway (15 (25%) unobstructed views; p < 0.0001) and a shorter time was needed to complete bronchoscopy (median (95% CI) difference 4 s (1–7); p = 0.01). Four (6.7%) bronchoscopies failed using the Williams Airway Intubator compared with 26 (43.3%) using the Ovassapian Fibreoptic Intubating Airway (p < 0.0001). Both airways provided similar intubating conditions when the glottis was visible. [ABSTRACT FROM AUTHOR]

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Surgery and anaesthesia subject the brain to considerable stress in the peri-operative period. This may be caused by potentially neurotoxic anaesthetic drugs, impaired cerebral perfusion and reperfusion injury related to surgery or thromboembolic events. Patient monitoring using electroencephalogram and cerebral oximetry can assist in optimising depth of anaesthesia and assessment of cerebral metabolic activity. However, research findings have been contradictory as to whether these monitors can help ameliorate peri-operative neurocognitive complications. In this narrative review, we will discuss recent evidence in the use of electroencephalography and cerebral oximetry and the underlying scientific principles. It is important to appreciate the raw electroencephalographic changes under anaesthesia and those associated with ageing, in order to interpret depth of anaesthesia indices correctly. Cerebral oximetry is useful not only for the detection of cerebral desaturation but also to identify those patients who are particularly vulnerable to injury, for better risk stratification. An algorithm-based approach may be most effective in managing the episodes of cerebral desaturation. [ABSTRACT FROM AUTHOR]