Clinical risk prediction and major surgery

We are delighted to present an original article and systematic review on the use of risk scores to predict 30-day mortality after surgery in this month’s issue of Anaesthesia. Darbyshire et al. evaluated the predictive ability of three novel risk scores for 30-day mortality after emergency bowel surgery. The results showed that the individual scores were reasonable predictors of mortality, but they were poorly calibrated. A logistic regression model that incorporated age, National Early Warning Score, Laboratory Decision Tree Early Warning Score, and Hospital Frailty Risk Score demonstrated good discrimination and calibration but was slightly less effective than the National Emergency Laparotomy Audit score. Meanwhile, in a systematic review, Vernooij et al. assessed prediction models for 30-day postoperative mortality in non-cardiac surgical cohorts. Although 10 models were evaluated, they were considered to have unclear or high risk of bias in their development. However, the surgical outcome risk tool (SORT) demonstrated the best combination of predictive performance and clinical usability. The accompanying editorial emphasises the importance of high predictive accuracy and clinical usability in the adoption of pre-operative mortality risk prediction models in routine clinical practice.

In older adult patients, postoperative cognitive disorders are a common occurrence. Although neuropsychiatric assessment is the gold standard for diagnosis, it is expensive and often unavailable in resource-limited healthcare settings. Zuylen et al. conducted a single-centre prospective observational study comparing simple neurocognitive tests, such as the Modified Telephone Interview for Cognitive Status and Montreal Cognitive Assessment, to neuropsychiatric testing. However, the results showed limited agreement between the tests (Fig. 1), indicating that these simplified tests should not be used in isolation to diagnose postoperative neurocognitive disorders.

Figure 1 Contingency table for postoperative neurocognitive disorders according to Modified Telephone Interview for Cognitive Status and Montreal Cognitive Assessment vs. neuropsychological assessment.

Aerosol-generating procedures are high risk interventions for airborne transmission of pathogens. Shrimpton et al.investigated the risk of aerosol generation during awake tracheal intubation and nasoendoscopy procedures, and found that they can generate high concentrations of respiratory aerosol, especially when lidocaine is sprayed on the vocal cords or the bronchoscope is passed through the vocal cords. The authors suggest that airborne infection control precautions are recommended for such procedures if respirable pathogens cannot be confidently excluded.

In this issue of Anaesthesia, two studies on the use of dexmedetomidine are presented. The first study examines the introduction of a nurse-led sedation service for magnetic resonance imaging in children using intravenous and intranasal dexmedetomidine. The study found an impressive overall sedation success rate of 98.4%, concluding that paediatric sedation with dexmedetomidine can be both safe and successful. The second study investigates the effect of dexmedetomidine on delirium after cardiac surgery. While the study found no significant difference in the incidence of delirium between the dexmedetomidine and saline groups (Fig. 2), the use of dexmedetomidine was associated with an increased risk of postoperative renal impairment.

Figure 2 Cumulative incidence of delirium for placebo(blue) and dexmedetomidine(red) groups. Log-rank p=0.65, 95% CI 0.68-1.56.

In the wake of the remifentanil shortage, Hughes et al explore alternative options for total intravenous anaesthesia, in a comprehensive narrative review. The review presents a range of compelling opioid (Fig. 3) and non-opioid analgesic (Fig. 4) options for TIVA, along with detailed explanations of their pharmacokinetic profiles. The authors’ thorough analysis is a valuable resource, providing an opportunity to explore lesser-known analgesics and broaden our practice.

Figure 3 Comparison between the properties of opioid analgesics.
Figure 4 An overview of non-opioid analgesic adjunctive drugs

Open science is a movement towards making scientific research, data, and dissemination freely accessible to all without any barriers or restrictions. It fosters collaboration and encourages the sharing of information and ideas among researchers, while also promoting the use of open-source software and tools to facilitate scientific research. In this issue, our editorial  explores the benefits and drawbacks of open science and takes a closer look at its current status in anaesthesia.

Figure 5 Key pillars to open science as proposed by the United Nations Educational, Scientific and Cultural Organisation (UNESCO).

This issue delves into two vital aspects of ICU management: viral infections and end of life care. Viral infections form a significant part of ICU workload, with managing them becoming more challenging due to increased availability of molecular diagnostics. This review provides an overview of managing viral infections in critical care, including complications, rare and emerging viruses, and the importance of infection control to prevent nosocomial viral transmission. In another review, Gutiez et al. address ethical dilemmas around withholding and withdrawing life-sustaining treatment, balancing paternalism and shared decision-making, legal challenges, conflict resolution, and practical issues. This review clarifies the differences between withdrawing/withholding treatment and euthanasia, offers practical suggestions for using sedation and analgesia, and advocates for family inclusion in decision-making. The article also proposes a step-escalation approach to family conflict and highlights the importance of communication skills in medical and nursing training.

This month’s Reviewers Recommendations examines how to measure academic impact.  Measuring academic impact is complex and multifactorial. This article discusses the strengths and weaknesses of existing metrics used to quantify or qualify academic impact, from individual researcher level to journal level. It explains that no single measure exists to accurately represent the impact of a researcher or an individual article, and thus a holistic approach drawing together multiple parameters should be taken to measure academic impact. The full collection of reviewers recommendations can be found here, and is an excellent ‘how to’ manual for all who wish to get involved with research and the communication of scientific fact and opinion.

Finally, don’t miss out on The Association of Anaesthetists Annual Congress 2023 in Edinburgh, from 13th-15th September. This highly anticipated in-person conference offers a wide range of diverse speakers, practical workshops, great clinical content and hands-on experience with the latest technology at the industry exhibition. Early booking is available until August 1st, 2023, so register here now.

Eimear Keane and Andrew Klein