Predicting the Need for Blood Transfusions in Cardiac Surgery: A Comparison between Machine Learning Algorithms and Established Risk Scores in the Brazilian Population

INTRODUCTION

Blood transfusion is a common practice in cardiac surgery, despite its well-known negative effects. To mitigate blood transfusion-associated risks, identifying patients who are at higher risk of needing this procedure is crucial. Widely used risk scores to predict the need for blood transfusions have yielded unsatisfactory results when validated for the Brazilian population.

METHODS

In this retrospective study, machine learning (ML) algorithms were compared to predict the need for blood transfusions in a cohort of 495 cardiac surgery patients treated at a Brazilian reference service between 2019 and 2021. The performance of the models was evaluated using various metrics, including the area under the curve (AUC), and compared to the commonly used Transfusion Risk and Clinical Knowledge (TRACK) and Transfusion Risk Understanding Scoring Tool (TRUST) scoring systems.

RESULTS

The study found that the model had the highest performance, achieving an AUC of 0.7350 (confidence interval [CI]: 0.7203 to 0.7497). Importantly, all ML algorithms performed significantly better than the commonly used TRACK and TRUST scoring systems. TRACK had an AUC of 0.6757 (CI: 0.6609 to 0.6906), while TRUST had an AUC of 0.6622 (CI: 0.6473 to 0.6906).

CONCLUSION

The findings of this study suggest that ML algorithms may offer a more accurate prediction of the need for blood transfusions than the traditional scoring systems and could enhance the accuracy of predicting blood transfusion requirements in cardiac surgery patients. Further research could focus on optimizing and refining ML algorithms to improve their accuracy and make them more suitable for clinical use.

Validation of Blood Transfusion Risk Scores (TRACK and TRUST) in a Cardiac Surgery Service in Brazil

INTRODUCTION

Transfusion of red blood cells is recurrent in cardiac surgery despite the well-established deleterious effects. Identifying patients with higher chances of requiring blood transfusion is essential to apply strategic preventive measures to reduce such chances, considering the restricted availability of this product. The most used risk scores to predict blood transfusion are the Transfusion Risk and Clinical Knowledge (TRACK) and Transfusion Risk Understanding Scoring Tool (TRUST). However, these scores were not validated for the Brazilian population. The objective of this study was to assess the accuracy of TRACK and TRUST scores in estimating the need for postoperative transfusion of red blood cell concentrates (TRBCC) after cardiac surgery.

METHODS

A clinical retrospective study was conducted using the database of a Brazilian reference service composed of patients operated between November 2019 and September 2021. Scores were compared using Mann-Whitney U test. Hosmer-Lemeshow goodness of fit test assessed calibration of the scores. Accuracy was assessed using the area under the receiver operating characteristic curve (AUC). All analyses considered a level of significance of 5%. The study was approved by the research ethics committee (CAAE 55577421.4.0000.5201).

RESULTS

This study assessed 498 patients. Only the TRACK score presented good calibration (P=0.238; TRUST P=0.034). AUC of TRACK was 0.678 (95% confidence interval 0.63 to 0.73; P<0.001), showing a significant accuracy.

CONCLUSION

Between the scores analyzed, only the TRACK score showed a good calibration, but low accuracy, to predict postoperative TRBCC after cardiac surgery.

Lack of knowledge on acute stroke in children, adolescents and adults from public schools

Introduction

Stroke is an important cause of disability and death in adults worldwide. However, it is preventable in most cases. This community-based study investigated students' stroke knowledge, emergency medical services (EMS) activation, associated risk factors, warning signs and symptoms, and prior experience from different educational levels.

Methods

We conducted the survey with a structured questionnaire between March 2019 and December 2020.

Results

Students from the elementary school (n=1,187, ∼13 y.o., 14% with prior experience, 51% women), high school (n=806, ∼17 y.o., 13% with prior experience, 47% women) and University (n=1,961, ∼22 y.o., 9% with prior experience, 66% women) completed the survey. Among the students, the awareness of stroke general knowledge, associated risk factors, and warning signs and symptoms varied between 42–66%. When stimulated, less than 52% of the students associated stroke with hypercholesterolemia, smoking, diabetes, and hypertension. When stimulated, 62–65% of students recognised arm weakness, facial drooping, and speech difficulty; only fewer identified acute headache (43%). Interestingly, 67% knew the EMS phone number; 81% were willing to have stroke education included at school, and 75.2% found it essential and mandatory. Female, higher education and prior experience were associated with higher scores of stroke risk factors (OR: 1.28, 95% CI: 1.10–1.48; OR: 2.12, 95% CI:1.87–2.40; and OR: 1.46, 95% CI: 1.16–1.83; respectively), and signs and symptoms (OR: 2.22, 95% CI: 1.89–2.60; OR: 3.30, 95% CI: 2.81–3.87; and OR: 2.04, 95% CI: 1.58–2.63; respectively).

Conclusion

Being female, having prior experience, and a higher educational level increase the identification of associated risk factors and warning signs and symptoms. Stroke awareness should be emphasized among schoolchildren and adolescents.

Funding Acknowledgement

Type of funding sources: None.

Avaliação Microbiológica dos Aparelhos Celulares dentro do Bloco Cirúrgico – Avaliação em um Hospital Beneficente de Pernambuco

Introdução: A infecção hospitalar tem sido um problema frequente e crescente em todo o mundo. Tentar determinar fatores que possam contribuir com a disseminação de bactérias dentro do ambiente hospitalar faz parte da estratégia de controle deste mal. Os telefones celulares, dispositivos presentes no cotidiano de qualquer ambiente, incluindo os estabelecimentos de saúde, podem servir de reservatórios de patógenos, e, em seu manuseio, ajudar na disseminação de infecção nos hospitais. Essa preocupação se eleva ao se tratar de aparelhos pertencentes a funcionários de ambientes potencialmente colonizados por bactérias resistentes. Objetivo: O objetivo deste trabalho foi avaliar o grau de contaminação dos aparelhos celulares dos funcionários de um bloco cirúrgico de um hospital, verificando se há diferença entre as funções destes profissionais, tais como cirurgiões, anestesistas, perfusionistas, enfermeiros, e instrumentadores. Métodos: Foram colhidos swabs umedecidos em caldo enriquecedor de 50 telefones celulares de funcionários do bloco cirúrgico. Esses swabs foram encubados e semeados, tendo suas leituras sido realizadas em 24 e 48h, tendo os resultados separados de acordo com cada especialidade. Resultados: Dos 50 aparelhos celulares avaliados, 88% (44) estavam colonizados. A bactéria mais comum foi o Estafilococos coagulase-negativa, seguido do Bacillus subtillis (15,9%) e Micrococcus sp (9,1%). Não houve diferença estatisticamente significativa do grau de contaminação entre as especialidades avaliadas. Conclusão: Assim como mostra a literatura, os telefones celulares estão contaminados por bactéria potencialmente infectantes, e por isso, medidas para regulamentar seu uso e antissepsia devem ser estipuladas pelas instituições.

Angina pectoris in patients with HIV/AIDS: prevalence and risk factors

INTRODUCTION

The incidence of ischemic heart disease is higher in patients with HIV/AIDS. However, the frequency of angina pectoris in these patients is still not known. Literature about this subject is still scarce.

OBJECTIVE

To evaluate the prevalence of angina pectoris and risk factors for coronary disease and to examine the association between traditional risk factors and HIV-related risk factors and angina pectoris.

METHOD

An epidemiological cross-sectional study, analyzed as case-control study, involving 584 patients with HIV/AIDS. Angina pectoris was identified by Rose questionnaire, classified as definite or possible. Information regarding risk factors was obtained through a questionnaire, biochemical laboratory tests, medical records and anthropometric measures taken during consultations at AIDS treatment clinics in Pernambuco, Brazil, from June 2007 to February 2008. To adjust the effect of each factor in relation to others, multiple logistic regression was used.

RESULTS

There was a preponderance of men (63.2%); mean ages were 39.8 years for men, 36.8 years for women. The prevalence of definite and possible angina were 11% and 9.4%, respectively, totaling 20.4%, with independent associations between angina and smoking (OR = 2.88; 95% CI: 1.69-4.90), obesity (OR = 1.62; 95% CI: 0.97-2.70), family history of heart attack (OR = 1.70; 95% CI: 1.00-2.88), low schooling (OR = 2.11; 95% CI: 1.24-3.59), and low monthly income (OR = 2.93; 95% CI: 1.18-7.22), even after adjustment for age.

CONCLUSION

This study suggests that angina pectoris is underdiagnosed, even in patients with medical monitoring, revealing lost opportunities in identification and prevention of cardiovascular morbidity.

Risk factors related to hypertension among patients in a cohort living with HIV/AIDS

INTRODUCTION

Studies disagree as to whether there is a greater prevalence of hypertension among HIV/AIDS patients and the role of antiretroviral therapy.

OBJECTIVE

Evaluate the prevalence of hypertension and risk factors in a cohort of HIV-infected patients, with emphasis on antiretroviral therapy.

METHOD

Case-control study conducted at baseline of a cohort, between June/2007 and December/2008 in Pernambuco/Brazil. Blood pressure was classified as normal, prehypertension, and hypertension.

RESULTS

Of 958 patients, 245 (25.6%) had hypertension (cases), 325 (33.9%) had prehypertension, and 388 (40.5%) were normotensive (controls). Comparison between hypertensive and normotensive patients showed that traditional factors, such as age > 40 (OR = 3.06, CI = 1.91-4.97), male gender (OR = 1.85, CI = 1.15-3.01), BMI > 25 (OR = 5.51, CI = 3.36-9.17), and triglycerides > 150 mg/dL (OR = 1.69, CI = 1.05-2.71), were independently associated with hypertension. Duration of antiretroviral therapy and CD4 > 200 cells/mm³ were associated with hypertension in univariate analysis, but did not remain in final model. Type of antiretroviral schema and lipodystrophy showed no association with hypertension.

CONCLUSION

Hypertension in HIV/AIDS patients is partially linked to invariable factors, such as age and sex. Efforts should be directed toward controlling reversible factors, particularly excessive weight gain and unsuitable diet.

Profile of patients with hypertension included in a cohort with HIV/AIDS in the state of Pernambuco, Brazil

BACKGROUND

Hypertension (HBP) is modifiable risk factor, whose control may reduce cardiovascular disease in patients with human immunodeficiency virus (HIV).

OBJECTIVE

To estimate the prevalence of hypertension and describe the characteristics of patients with hypertension infected by HIV/AIDS.

METHODS

A cross-sectional study aligned to a cohort of patients with HIV/AIDS. The study considered hypertension at levels > 140/90 mmHg or use of antihypertensive drugs and pre-hypertension at levels > 120/80 mmHg.

RESULTS

Out of 958 patients, 388 (40.5%) were normotensive, 325 (33.9%) were pre-hypertensive, and 245 (25.6%) were hypertensive. Out of these 245 patients, 172 (70.2%) were aware of the fact there they were hypertensive, and 36 (14.8%) had blood pressure controlled. Sixty-two (62) patients (54.4%) were diagnosed with hypertension after HIV diagnosis. Lipodystrophy occurred in 95 (46.1%) patients; overweight/obesity in 129 (52.7%). Use of antiretrovirals occurred in 184 (85.9%), 89 (41.6%) with protease inhibitors (PI) and 95 (44.4%) without PI. Out of these patients, 74.7 used antivirals > 24 months. Age, family history of hypertension, waist circumference, body mass index and triglyceride levels were higher among hypertensive patients. Time of HIV infection, CD4 count, viral load, time and type of antiretroviral regimen were similar in hypertensive and prehypertensive patients.

CONCLUSION

The high frequency of uncontrolled hypertensive patients and cardiovascular risks in HIV-infected patients point out to the need for preventive and therapeutic measures against hypertension in this group.