Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

BURDEN OF CYTOPAENIAS AMONG HIV POSITIVE PREGNANT WOMEN AT THE UNIVERSITY COLLEGE HOSPITAL, IBADAN

INTRODUCTION

Few studies have examined cytopaenia among HIV positive pregnant women.

OBJECTIVES

To assess burden of cytopaenia among HIV positive pregnant women.

METHODOLOGY

This cross-sectional study of women on HAART ≤6months, defined anemia as hematocrit <33%, leucopenia as total white blood cell count <3,000 cells/mm3 and thrombocytopenia as absolute platelet count <100,000 cells/mm3. Univariate and bivariate analyses were performed.

RESULTS

Over 8 years, of 1,197 women, the mean age was 29.02(±5.4) years and mean gestational age 25.9(±8.1) weeks. Prevalence of anaemia was 76.8%, leucopaenia 6.9% and thrombocytopenia 4.7%. The mean haematocrit was 28.5%(±4.5); median white blood count 5,500/mm3 ; median platelet count 200,000/mm3 and median CD4 323 cells/mm3. Mean haematocrit was highest (29.7%±5.3) in women in the first trimester but lowest (28.4% ±4.6) in women in second trimester (p=0.04). Compared with earlier trimesters, women in the third trimester had higher median white blood count (5,600 cells/mm3), higher neutrophil (61.0% ±11.2) but lower lymphocytes (28.3%± 9.2) (p=0.18; 0.00, 0.00). Median absolute platelet count was highest (206,000 cells/mm3) in the first trimester but lowest (195,000 cells/mm3) in third trimester (0.04). Women with lower CD4 had higher prevalence of cytopaenias.

CONCLUSION

Cytopaenias are not uncommon in this population especially with lower CD4.

APOL1, CDKN2A/CDKN2B, and HDAC9 polymorphisms and small vessel ischemic stroke

OBJECTIVE

Worldwide, the highest frequencies of APOL1-associated kidney variants are found in indigenous West Africans among whom small vessel disease (SVD) ischemic stroke is the most common stroke phenotype. The objective of this study was to investigate the association and effect sizes of 23 selected SNPs in 14 genes of relevance, including the APOL1 G1 variants, with the occurrence of SVD ischemic stroke among indigenous West African participants in the Stroke Investigative Research and Education Network (SIREN) Study.

MATERIALS AND METHODS

Cases were consecutively recruited consenting adults (aged 18 years or older) with neuroimaging-confirmed first clinical stroke. Stroke-free controls were ascertained using a locally validated version of the Questionnaire for Verifying Stroke-Free Status (QVSFS). Logistic regression models adjusting for known vascular risk factors were fitted to assess the associations of the 23 SNPs in rigorously phenotyped cases (N = 154) of SVD ischemic stroke and stroke-free (N = 483) controls.

RESULTS

Apolipoprotein L1 (APOL1) rs73885319 (OR = 1.52; CI: 1.09-2.13, P-value = .013), rs2383207 in CDKN2A/CDKN2B (OR = 3.08; CI: 1.15-8.26, P -value = .026) and rs2107595 (OR = 1.70; CI: 1.12-2.60, P-value = .014) and rs28688791 (OR = 1.52; CI: 1.03-2.26, P-value = .036) in HDAC9 gene were associated with SVD stroke at 0.05 significance level. Polymorphisms in other genes did not show significant associations.

CONCLUSION

This is the first report of a specific association of APOL1 with a stroke subtype. Further research is needed to confirm these initial findings and deepen understanding of the genetics of stroke in people of African ancestry with possible implications for other ancestries as all humans originated from Africa.

Prevalence and predictors of anxiety in an African sample of recent stroke survivors

OBJECTIVES

Studies considering emotional disturbances in the setting of stroke have primarily focused on depression and been conducted in high-income countries. Anxiety in stroke survivors, which may be associated with its own unique sets of risk factors and clinical parameters, has been rarely investigated in sub-Saharan Africa (SSA). We assess the characteristics of anxiety and anxiety-depression comorbidity in a SSA sample of recent stroke survivors.

MATERIALS AND METHODS

We assessed baseline data being collected as part of an intervention to improve one-year blood pressure control among recent (≤1 month) stroke survivors in SSA. Anxiety in this patient population was measured using the Hospital Anxiety and Depression Scale (HADS), while the community screening instrument for dementia was used to evaluate cognitive functioning. Independent associations were assessed using logistic regression analysis.

RESULTS

Among 391 participants, clinically significant anxiety (HADS anxiety score≥11) was found in 77 (19.7%). Anxiety was comorbid with depression in 55 (14.1%). Female stroke survivors were more likely than males to have anxiety (OR=2.4, 95% CI=1.5-4.0). Anxiety was significantly associated with the presence of cognitive impairment after adjusting for age, gender and education (OR=6.8, 95% CI=2.6-18.0).

CONCLUSIONS

One in five recent stroke survivors in SSA has clinically significant anxiety, and well over 70% of those with anxiety also have depression. Future studies will need to determine what specific impact post-stroke anxiety may have on post-stroke clinical processes and outcomes.