Risk factors and interventions associated with mortality or survival in adult COVID-19 patients admitted to critical care: a systematic review and meta-analysis

Background: Patients with confirmed COVID-19 admitted to intensive care units have a high mortality rate, which appears to be associated with increasing age, male sex, smoking history, hypertension and diabetes mellitus. Methods: A systematic review to determine risk factors and interventions associated with mortality/survival in adult patients admitted to an intensive care unit (ICU) with confirmed COVID-19/SARS-CoV-2 infection. The protocol was registered with PROSPERO (CRD42020181185). Results: The search identified 483 abstracts between 1 January and 7 April 2020, of which nine studies were included in the final review. Only one study was of low bias. Advanced age (odds ratio [OR] 11.99, 95% confidence interval [CI] 5.35–18.62) and a history of hypertension were associated with mortality (OR 4.17, 95% CI 2.90–5.99). Sex was not associated with mortality. There was insufficient data to assess the association between other comorbidities, laboratory results or critical care risk indices and mortality. The critical care interventions of mechanical ventilation (OR 6.25, 95% CI 0.75–51.93), prone positioning during ventilation (OR 2.06, 95% CI 0.20–21.72), and extracorporeal membrane oxygenation (ECMO) (OR 8.00, 95% CI 0.69, 92.33) were not associated with mortality. The sample size was insufficient to conclusively determine the association between these interventions and ICU mortality. The need for inotropes or vasopressors was associated with mortality (OR 6.36, 95% CI 1.89–21.36). Conclusion: The studies provided little granular data to inform risk stratification or prognostication of patients requiring intensive care admission. Larger collaborative research is needed to address this limitation.

The prevalence of substance use in anaesthesia practitioners in South Africa

Background: In the United States the mortality associated with substance abuse among anaesthesia residents is twice that of non-anaesthesia residents. Since no data exist, the primary objective of this cross-sectional study was to establish the prevalence of substance use in South African anaesthesia practitioners. Secondary objectives were to compare the prevalence in male and female practitioners, and in private and state practice anaesthetists. Years of experience and level of training were explored as possible risk factors for hazardous or harmful use. Methods: Participants completed a self-administered, validated WHO questionnaire, over a ten-day period surrounding the 2018 South African Society of Anaesthesiologists (SASA) congress. All doctors practising anaesthesia in South Africa were eligible. Recruitment was via an email link sent to all SASA members, as well as a web-based link at the congress. Results: A total of 1 961 SASA members and 113 non-members (anaesthesiologists, registrars and non-specialists) were invited to participate (total 2 074). There were 434 responses (response rate 20.9%, margin of error 4.18%); 364 were suitable for analysis. The most commonly lifetime-used substances were alcohol (92.8%), tobacco (42.3%), cannabis (34.7%), and sedatives (34.4%). Questionnaire scores defined low-, medium- and high-risk categories according to substance use during the previous three months. Sedative (12.6%) and alcohol (12.1%) users were deemed to be at moderate risk. The prevalence of opioid use was 1.9% (n = 7). Prevalence of substance use was similar in male and female practitioners, as well as in those working in private practice or in state hospitals. Conclusion: The prevalence of current use of alcohol and sedatives is of major concern. A significant proportion of respondents were assessed to be at moderate risk of hazardous or harmful substance use. Gender and practice setting have little impact on substance use. Wellness efforts should be aimed at all anaesthesia practitioners in South Africa.

Association study of eight candidate genes with renin status in mild-to-moderate hypertension in patients of African ancestry

AIM

We evaluated whether any one variant of genes that encode for substances that could modulate renin-angiotensin-aldosterone (RAA) system activity can account for a substantial proportion of the variability of plasma RAA system profiles in black South African hypertensives (HTs).

METHODS

Plasma renin activity (PRA) and aldosterone concentrations (ALD) were determined in 59 black subjects with mild-to-moderate HT off therapy on an ad libitum diet. Patients were genotyped for the angiotensin-converting enzyme (ACE) gene insertion/deletion, angiotensinogen (AGT) gene M235T, A-20C and G-6A, aldosterone synthase (CYP11B2) gene C-344T, G protein beta3-subunit (GNB3) gene C825T, G(s) protein gene C131T, atrial natriuretic peptide (ANP) gene exon 3 stop condon and intron 2, alpha-adducin gene Gly460Trp, and epithelial Na(+) channel (eNa(+) (c)) gene T594M polymorphisms.

RESULTS

Risk genotype frequencies for the G(s) (7%), ANP intron 2 (0%), and eNa(+)(c)(7%) variants were too low for each to account for a substantial portion of the variability of plasma RAA profiles in the group studied. Moreover, assuming either recessive or dominant inheritance models, neither ACE, AGT, GNB3, CYP11B2, ANP exon 3 nor alpha-adducin polymorphisms were significantly associated with the variance of PRA, ALD or ALD/PRA.

CONCLUSIONS

These results do not support a substantial individual role for the gene candidates studied in contributing to plasma RAA system profiles in black South African HTs. However, a potential small role for some loci may exist, and epistasis or genotype-phenotype interactions as well as alternative inheritance models and variants still need to be evaluated.