Preoperative anemia as a marker of postoperative outcomes: a retrospective cohort study
Anemia pré-operatória como marcador de desfechos pós-operatórios: um estudo de coorte retrospectivo
Liege Caroline Immich, Liliane Ghi Mei Law, Igor Heineck Ouriques, Yan Prates Pimentel, Christian Camatti Menegon, Florentino Fernandes Mendes
Abstract
Background
Preoperative anemia is common and associated with adverse postoperative outcomes.
Objective
To evaluate the association between preoperative anemia severity and clinical outcomes in patients undergoing elective noncardiac surgery.
Methods
This retrospective cohort included 23,579 adults assessed preoperatively between January 2015 and August 2025, all with documented hemoglobin (Hb) and hospitalized for noncardiac surgery. Patients were stratified as no anemia (≥ 13 g.dL⁻¹), mild (11.1‒12.9 g.dL⁻¹), moderate (8.1‒11.0 g.dL⁻¹), or severe anemia (≤ 8.0 g.dL⁻¹). Outcomes were in-hospital mortality, Intensive Care Unit (ICU) admission, and Length of Stay (LOS). Analyses used Poisson regression with robust variance adjusted for confounders.
Results
Among the participants, 15,909 (67.5%) had no anemia, 6,396 (27.1%) mild, 1,174 (5.0%) moderate, and 100 (0.4%) severe anemia. Overall, 62.6% were female, and the mean age was 60.7 years (SD ±15,4). Compared with no anemia, all anemia categories were independently associated with higher in-hospital mortality, increased ICU admission, and longer LOS. Severe anemia was the strongest predictor of in-hospital mortality (adjusted RR = 24.7; 95% CI 13.3‒ 46.0; p < 0.001). Intermediate or major surgeries (RR = 4.7; 95% CI 3.4‒6.6), age > 54 years (RR = 4.4; 95% CI 2.6‒7.6), and male sex (RR = 2.1; 95% CI 1.6‒2.9) were also independent predictors of in-hospital mortality.
Conclusion
Preoperative anemia, even when mild, was independently associated with higher in-hospital mortality, greater ICU admission, and prolonged hospitalization. These results support systematic screening and targeted management, including Patient Blood Management (PBM) strategies, to improve perioperative outcomes.
Keywords
Resumo
Introdução
A anemia pré-operatória é comum e está associada a desfechos pós-operatórios adversos.
Objetivo
Avaliar a associação entre a gravidade da anemia pré-operatória e desfechos clínicos em pacientes submetidos a cirurgia eletiva não cardíaca.
Métodos
Esta coorte retrospectiva incluiu 23.579 adultos avaliados no pré-operatório entre janeiro de 2015 e agosto de 2025, todos com hemoglobina (Hb) documentada e hospitalizados para cirurgia não cardíaca. Os pacientes foram estratificados em: sem anemia (≥ 13 g.dL⁻¹), anemia leve (11,1‒12,9 g.dL⁻¹), moderada (8,1‒11,0 g.dL⁻¹) ou grave (≤ 8,0 g.dL⁻¹). Os desfechos foram mortalidade intra-hospitalar, admissão em Unidade de Terapia Intensiva (UTI) e tempo de internação (TI). As análises utilizaram regressão de Poisson com variância robusta, ajustada para fatores de confusão.
Resultados
Entre os participantes, 15.909 (67,5%) não apresentavam anemia, 6.396 (27,1%) apresentavam anemia leve, 1.174 (5,0%) moderada e 100 (0,4%) grave. No total, 62,6% eram do sexo feminino, e a idade média foi de 60,7 anos (DP ±15,4). Em comparação com pacientes sem anemia, todas as categorias de anemia estiveram independentemente associadas a maior mortalidade intra-hospitalar, maior admissão em UTI e maior tempo de internação. A anemia grave foi o preditor mais forte de mortalidade intra-hospitalar (RR ajustado = 24,7; IC 95% 13,3‒46,0; p < 0,001). Cirurgias intermediárias ou de grande porte (RR = 4,7; IC 95% 3,4‒6,6), idade > 54 anos (RR = 4,4; IC 95% 2,6‒7,6) e sexo masculino (RR = 2,1; IC 95% 1,6‒2,9) também foram preditores independentes de mortalidade intra-hospitalar.
Conclusion
A anemia pré-operatória, mesmo quando leve, esteve independentemente associada a maior mortalidade intra-hospitalar, maior necessidade de admissão em UTI e prolongamento da internação. Esses resultados sustentam a triagem sistemática e o manejo direcionado, incluindo estratégias de Patient Blood Management (PBM), para melhorar os desfechos perioperatórios.
Palavras-chave
References
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Submitted date:
10/27/2025
Accepted date:
03/19/2026
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