Letter to the editor: The impact of introducing drug labelling at Grey’s Hospital Theatre over a six-month period

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Induction behaviour and race and its association with postoperative agitation in paediatric elective surgery

Background: It has been suggested that preoperative agitation in children may be a risk factor for postoperative delirium and postoperative vomiting. Previous studies have suggested that adult African patients have a lower incidence of postoperative nausea and vomiting, but no such association has been shown in children.Aim: To determine the incidence of both postoperative delirium and postoperative vomiting in elective paediatric surgical patients in a South African hospital and their association with preoperative agitation and patient race.Methods: A retrospective database analysis was undertaken of patients 1–12 years of age undergoing elective surgery. The Watcha behavioural scale was used to assess pre- and postoperative agitation. A Watcha score > 2 defined significant preoperative agitation or postoperative delirium. Multivariable logistic regression evaluated ENT surgery, sex, age, volatile type, significant preoperative agitation and race as predictors of postoperative delirium. Sex, race, significant preoperative agitation, ENT surgery and vomiting prophylaxis were evaluated as predictors of postoperative vomiting.Results: Significant preoperative agitation occurred in 13.5% (125/928); postoperative delirium in 3.4% (32/928) and postoperative vomiting in 1.4% (12/856) of patients. Postoperative delirium occurred in 3.1% of African patients as compared with 10.4% of non-African patients (p = 0.007); and postoperative vomiting in 1.2% of African patients as compared with 4.4% of non-African patients (p = 0.074). The predictors of postoperative delirium were non-African race (odds ratio [OR] 3.67; 95% confidence interval [CI] 1.22–11.07; p = 0.021), significant preoperative agitation (OR 3.54; 95% CI 1.55–8.09; p = 0.003), and ENT surgery (OR 2.5; 95% CI 1.0–6.0; p = 0.040). Only non-African race predicted postoperative vomiting (OR 3.73; 95% CI 1.01–13.79; p = 0.049), which included other variables like ENT surgery, significant preoperative anxiety, PONV prophylaxis.Conclusion: Preoperative agitation, non-African race and ENT surgery were predictors of postoperative agitation. Postoperative vomiting was predicted only by non-African race, which correlates with the trend seen in adults, even though incidence difference between African and non-African patients was not statistically significant.Keywords: emergence agitation, emergence deliriuminduction behaviour, preoperative agitation, preoperative anxiet

Bibliometrics to assess the productivity and impact of medical research

Background: Bibliometrics is the use of statistical and mathematical analysis to assess research production and quality. These metrics provide important insights into the quality and impact of research by applying standardised metrics. However, there are inherent limitations in their application. Objective: We aimed to review existing bibliometric indices and assess their comparative utility in the assessment of medical researchers. We specifically aimed to evaluate the utility of the h-index in identifying young or developing medical researchers with future research potential. Method: We conducted a focussed literature review on commonly used bibliometrics. To explore the utility of these metrics we then used them to evaluate a sample of researchers from a South African medical school faculty. Researchers were ranked with the following metrics: number of publications; h-index; citations per paper; citations per paper per year; and m-index. The h-index, citations and publication counts were drawn from ResearchGate and, if not available, from Google Scholar. The top 20 researchers, based on publication count, were then analysed further. Results: We identified 145 researchers for analysis of which 37 were excluded due to an inability to obtain additional information. Higher time-dependent metrics (publication count, citation count, h-index) were directly proportional to years since first publication. Indices that corrected for time, such as the m-index, provided more insight and better discrimination in identifying younger researchers with greater research potential. Conclusion: Bibliometrics have utility as part of the assessment of academic output but may be subject to time-dependent bias. Research quality is best measured using the h-index, g-index and m-index. The h-index is limited by being time dependent and field specific and overlooks highly cited papers. Bibliometrics that account for time, such as the m-index, should be considered in the early identification of young researchers, ideally accompanied by critical peer review

Perioperative ARDS and lung injury: for anaesthesia and beyond

Postoperative pulmonary complications are common and may be associated with significant cost. Acute respiratory distress syndrome (ARDS), a life-threatening respiratory disease process characterised by hypoxaemia and reduced lung compliance, is one of the more serious pulmonary complications. The development of ARDS or the related entity of lung injury is associated with prolonged hospitalisation, ventilation, and time spent in intensive care, and profoundly increases the risk of mortality and significant morbidity. Patients with, or at risk of ARDS and lung injury, must be identified, optimised and managed with sound intraoperative principles (particularly ventilation and fluid management) – with the specific aim of limiting harm. This review will focus on the diagnosis, pathophysiology, prevention and management of ARDS and lung injury in the perioperative period.Keywords: acute lung injury, anaesthesia, ARDS, ventilatio

Preoperative B-type natriuretic peptides in patients undergoing noncardiac surgery: a cumulative meta-analysis

Background: A plethora of studies have shown elevated preoperative natriuretic peptide measurements to predict postoperative mortality and adverse cardiac events.Objectives: The current study aimed to demonstrate this overwhelming association and to show that further studies of this nature are unwarranted.Methods: A cumulative meta-analysis of 28 studies was conducted where the primary outcomes of  mortality and adverse cardiac events were associated with elevated preoperative natriuretic peptides.Results: Cumulative meta-analysis demonstrated an odds ratio trending to a constant of 5.66, with a marked narrowing in the 95% confidence interval.Conclusions: Further studies aiming only to demonstrate an association between a preoperative natriuretic peptide threshold and the risk of postoperative adverse cardiac events are not justified. Future investigation should focus on the clinical implications of these data and the application of these findings with regard to further investigation, optimisation and appropriate adaptation of perioperative management.Keywords: BNP, major adverse cardiac event, myocardial injury, natriuretic peptides, non-cardiac surgery, NT-proBNP, outcome

Natriuretic peptide-directed medical therapy: a systematic review

Abstract Natriuretic peptides (NP) are strongly associated with perioperative cardiovascular events. However, in patients with raised NP, it remains unknown whether treatment to reduce NP levels prior to surgery results in better perioperative outcomes. In this systematic review and meta-analysis, we investigate NP-directed medical therapy in non-surgical patients to provide guidance for NP-directed medical therapy in surgical patients. The protocol was registered with PROSPERO (CRD42017051468). The database search included MEDLINE (PubMed), CINAHL (EBSCO host), EMBASE (EBSCO host), ProQuest, Web of Science, and Cochrane database. The primary outcome was to determine whether NP-directed medical therapy is effective in reducing NP levels within 6 months, compared to standard of care. The secondary outcome was to determine whether reducing NP levels is associated with decreased mortality. Full texts of 18 trials were reviewed. NP-directed medical therapy showed no significant difference compared to standard care in decreasing NP levels (standardized mean difference − 0.04 (− 0.16, 0.07)), but was associated with a 6-month (relative risk (RR) 0.82 (95% confidence interval (CI) 0.68–0.99)) reduction in mortality

Predicting postoperative haemoglobin changes after burn surgery

Background. Burn surgery is associated with significant blood loss and fluid shifts that cause rapid haemoglobin (Hb) changes during and after surgery. Understanding the relationship between intraoperative and postoperative (day 1) Hb changes may assist in avoiding postoperative anaemia and unnecessary peri-operative blood transfusion.Objective. To describe the Hb changes into the first day after burn surgery and to identify factors predictive of Hb changes that would guide blood transfusion decisions.Methods. This was a single-institution, retrospective cohort study that included 158 patients who had undergone burn surgery. Hb was measured at the start and end of surgery, and on the first day (16 - 32 hours) after surgery, and the results were analysed. Peri-operative factors (Hb at the end of surgery, total body surface area operated on (TBSA-op), fluid administration and intraoperative blood administration) were evaluated to determine their association with Hb changes on the first day after surgery.Results. The mean (standard deviation) preoperative Hb was 10.6 (2.29) g/dL, the mean postoperative Hb was 9.4 (2.01) g/dL, and the mean Hb on the first day after surgery was 9.2 (2.19) g/dL. Median total burn surface area was 7% (interquartile range 9%, min. 1%, max. 45%), with a mean body surface area operated on (debridement area plus donor area) of 9.7%. Of the 158 patients, 26 (16%) had an Hb <7 g/dL (transfusion trigger) on the first day after surgery. For patients with a high (≥9 g/dL), intermediate (≥7 - <9 g/dL), or low (<7 g/dL) Hb measurement at the end of burn surgery, those with an Hb below the transfusion trigger on the first day after burn surgery were 0%, 27%, and 75%, respectively. End-of-surgery Hb and TBSA-op strongly predicted the first day Hb level. In the intermediate group, 55% of patients with a TBSA-op ≥11% had an Hb below the transfusion trigger on the first day after surgery.Conclusion. Hb at the end of burn surgery was the best predictor of Hb on the first day after surgery. Patients with an Hb <7 g/dL remained as such on the first postoperative day. Half of the patients with an end-of-surgery Hb ≥7 - <9 g/dL and who had ≥11% TBSA-op had an Hb <7 g/dL on the first postoperative day

Recipes for obstetric spinal hypotension: The clinical context counts

Hypotension following obstetric spinal anaesthesia remains a common and important problem. While recent research advances have brought us closer to the perfect recipe for the obstetric spinal anaesthetic, these advances have not been translated into practical guidelines able to reduce the unacceptable number of fatalities that occur in environments where resources are limited. In South Africa, more than half of anaesthetic deaths are still related to spinal hypotension. A gap exists between the ‘perfect recipe’, developed from a clinical context rooted in resource-rich research environments, and its application and performance in real-world resource-poor environments – conditions experienced by more than 75% of the world’s population. This review attempts to define this knowledge gap and proposes a research agenda to address the deficiencies