Substance use disorder in anaesthetists: A personal perspective

In this article, I present a firsthand account as an anaesthetist with substance use disorder who has been through rehabilitation and returned to clinical anaesthesia, followed by an overview of substance use disorder in anaesthesia. Substance use disorder is prevalent within the anaesthesia community and can result in tragic consequences, including death in many cases. The incidence is around one to two per 1000 anaesthetist years and this appears to be rising, perhaps mirroring the population-wide increase in substance use disorder as a result of the opioid epidemic. Recognising substance use disorder in a colleague and intervening to try and help them and protect patients can be immensely challenging. Carrying out a successful intervention requires careful planning and coordination in order to protect the affected individual, their colleagues and patients. Returning to clinical anaesthesia following a diagnosis of substance use disorder is also contentious, with the high abstinence rate (relative to the wider substance use disorder population) having to be balanced against the risk of death following relapse. Any return to practice must be well planned and supported, and include appropriate toxicology screening. With such measures, rehabilitation and a return to clinical anaesthesia is possible in certain cases. For the affected individual regaining, then maintaining, their professional identity can be a powerful motivator to remain abstinent. Drug diversion and substance use disorder in anaesthesia is unlikely ever to be fully preventable, but strategies such as biometric dispensing, analysis of unused drugs, random toxicology and ongoing education may help to keep it to a minimum.

Cricoid pressure controversies

Rapid sequence induction (RSI) is a common technique used in clinical anaesthesia to prevent pulmonary aspiration of gastric contents. Sellick introduced this in 1961. However, scientific validation to show the advantage of this technique in preventing aspiration is limited in literature. Numerous researches have shown that cricoid pressure (CP) application might have no benefit in preventing aspiration. Additionally this could lead to problems in securing the airway. Proper teaching and regular training sessions of this technique are mandatory in routine anaesthesia practice.

The brain-bases of responsiveness variability under moderate anaesthesia

Anaesthesia combined with functional neuroimaging provides a powerful approach for understanding the brain mechanisms that change as consciousness fades. Although propofol is used ubiquitously in clinical interventions that reversibly suppress consciousness, its effect varies substantially between individuals, and the brain bases of this variability remain poorly understood. We asked whether three networks that are primary sites of propofol-induced sedation and key to conscious cognition — the dorsal attention (DAN), executive control (ECN), and default mode (DMN) network — underlie responsiveness variability under anaesthesia. Healthy participants (N=17) underwent propofol sedation inside the fMRI scanner at dosages of ‘moderate’ anaesthesia, and behavioural responsiveness was measured with a target detection task. To assess information processing, participants were scanned during an active engagement condition comprised of a suspenseful auditory narrative, in addition to the resting state. A behavioural investigation in a second group of non-anesthetized participants (N=25) qualified the attention demands of narrative understanding, which we then related to the brain activity of participants who underwent sedation. 30% of participants showed no delay in reaction times relative to wakefulness, whereas the others, showed significantly delayed and fragmented responses, or full omission of responses. These responsiveness differences did not relate to information processing differences. Rather, only the functional connectivity within the ECN during wakefulness differentiated the participants’ responsiveness level, with significantly stronger connectivity in the fast relative to slow responders. Consistent with this finding, fast responders had significantly higher grey matter volume in the frontal cortex aspect of the ECN. For the first time, these results show that responsiveness variability during propofol anaesthesia relates to inherent differences in brain function and structure within the executive control network, which can be predicted prior to sedation. These results shed light on the brain bases of responsiveness differences and highlight novel markers that may help to improve the accuracy of awareness monitoring during clinical anaesthesia.

A three-dimensional (3D) printed paediatric trachea for airway management training

There is a deficit of commercially available paediatric airway models for anaesthesia airway management training, particularly for infant front-of-neck access and customised airway planning. Acknowledging this, we created a three-dimensional printed prototype for an affordable, high-fidelity training device, incorporating realistic tactile feedback, reproducibility and potential for modification for specific patient pathologies. Our model, created on a Stratasys Polyjet J750™ (Rehovot, Israel) printer, is a novel and useful educational tool in paediatric airway management, and we are pleased to share access to this resource with readers. Our work adds credence to three-dimensional printing as an accessible, reproducible and pluripotent technology in clinical anaesthesia.