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Summary: The amount of aerosol generation associated with the use of positive pressure ventilation via a supraglottic airway device has not been quantified. We conducted a two‐group, two‐centre, prospective cohort study in which we recruited 21 low‐risk adult patients scheduled for elective surgery under general anaesthesia with second‐generation supraglottic airway devices. An optical particle sizer and an isokinetic sampling probe were used to record particle concentrations per second at different size distributions (0.3–10 μm) during use as well as baseline levels during two common activities (conversation and coughing). There was a median (IQR [range]) peak increase of 2.8 (1.5–4.5 [1–28.1]) and 4.1 (2.0–7.1 [1–18.2]) times background concentrations during SAD insertion and removal. Most of the particles generated during supraglottic airway insertion (85.0%) and removal (85.3%) were < 3 μm diameter. Median (IQR [range]) aerosol concentration generated by insertion (1.1 (0.6–5.1 [0.2–22.3]) particles.cm−3) and removal (2.1 (0.5–3.0 [0.1–18.9]) particles.cm−3) of SADs were significantly lower than those produced during continuous talking (44.5 (28.3–70.5 [2.0–134.5]) particles.cm−3) and coughing (141.0 (98.3–202.8 [4.0–296.5]) particles.cm−3) (p < 0.001). The aerosol levels produced were similar with the two devices. The proportion of easily inhaled and small particles (<1 μm) produced during insertion (57.5%) and removal (57.5%) was much lower than during talking (99.1%) and coughing (99.6%). These results suggest that the use of supraglottic airway devices in low‐risk patients, even with positive pressure ventilation, generates fewer aerosols than speaking and coughing in awake patients. [ABSTRACT FROM AUTHOR]

Summary: Propfol‐remifentanil‐based total intravenous anaesthesia has dominated recent clinical practice due to its favourable pharmacokinetic profile. Interruption in remifentanil supply has presented an opportunity to diversify or even avoid the use of opioids and consider adjuncts to propofol‐based total intravenous anaesthesia. Propofol, while a potent hypnotic, is not an effective analgesic. The administration of opioids, along with other adjuncts such as α‐2 adrenoceptor agonists, magnesium, lidocaine, ketamine and nitrous oxide provide surgical anaesthesia and avoids large doses of propofol being required. We provide an overview of both target‐control and manual infusion regimes for the alternative opioids: alfentanil, sufentanil and fentanyl. The optimal combination of hypnotic‐opioid dose, titration sequence and anticipated additional postoperative analgesia required depend on the chosen combination. In addition, we include a brief discussion on the role of non‐opioid adjuncts in total intravenous anaesthesia, suggested doses and expected reduction in propofol dose. [ABSTRACT FROM AUTHOR]

This article discusses the use of electronic cigarettes (e-cigarettes) as a smoking cessation intervention in the peri-operative period. The authors highlight that while e-cigarettes have been found to be effective in increasing abstinence from tobacco smoking in the general population, their impact in the peri-operative population is still uncertain. The article raises concerns about the potential respiratory, cardiovascular, and wound complications associated with e-cigarette use, as well as the potential interaction between e-liquids and anaesthetic drugs. The authors acknowledge the benefits of smoking cessation but challenge the idea that e-cigarettes are a transformative intervention in the peri-operative period. [Extracted from the article]

Summary: Various techniques have been explored to prolong the duration and improve the efficacy of local anaesthetic nerve blocks. Some of these involve mixing local anaesthetics or adding adjuncts. We did a literature review of studies published between 01 May 2011 and 01 May 2021 that studied specific combinations of local anaesthetics and adjuncts. The rationale behind mixing long‐ and short‐acting local anaesthetics to hasten onset and extend duration is flawed on pharmacokinetic principles. Most local anaesthetic adjuncts are not licensed for use in this manner and the consequences of untested admixtures and adjuncts range from making the solution ineffective to potential harm. Pharmaceutical compatibility needs to be established before administration. The compatibility of drugs from the same class cannot be inferred and each admixture requires individual review. Precipitation on mixing (steroids, non‐steroidal anti‐inflammatory drugs) and subsequent embolisation can lead to serious adverse events, although these are rare. The additive itself or its preservative can have neurotoxic (adrenaline, midazolam) and/or chondrotoxic properties (non‐steroidal anti‐inflammatory drugs). The prolongation of block may occur at the expense of motor block quality (ketamine) or block onset (magnesium). Adverse effects for some adjuncts appear to be dose‐dependent and recommendations concerning optimal dosing are lacking. An important confounding factor is whether studies used systemic administration of the adjunct as a control to accurately identify an additional benefit of perineural administration. The challenge of how best to prolong block duration while minimising adverse events remains a topic of interest with further research required. [ABSTRACT FROM AUTHOR]

With different pharmacokinetics in a drug mixture, a decision must be made to guide the infusion by one of the drugs with the potential risk of over- or under-dosing the other. The Medicines and Healthcare products Regulatory Agency in the UK and the US Food and Drug Administration have not approved the use of other medications including ketamine, remifentanil and dexmedetomidine but these practices have gained popularity. In some circumstances, there may be persuasive reasons for mixing two or more parenteral drug solutions, such as difficult intravenous access or in palliative care syringe drivers, but most of these situations are not applicable to routine intra-operative drug administration. Keywords: pharmacokinetics: pharmacodynamics; pharmacology; safety EN pharmacokinetics: pharmacodynamics pharmacology safety 260 263 4 02/07/22 20220301 NES 220301 The development and refinement of anaesthetic drugs and their administration have markedly increased safety and titratability while decreasing morbidity. [Extracted from the article]

We read with great interest the guidelines on malignant hyperthermia (MH) by Hopkins et al. [1]. We would like to highlight a rare, but potentially serious, situation that may occur due to the requirement for a general anaesthetic to facilitate the delivery of an MH-susceptible fetus where there is suspected or confirmed paternal MH. Suxamethonium was used as the neuromuscular blocking drug for tracheal intubation in 84.5% of cases and, while only small amounts of suxamethonium are likely to cross the placenta, it is possible for it to be an MH-triggering drug in a fetus. [Extracted from the article]