Meta-analysis of the association between preoperative anaemia and mortality after surgery (original) (raw)
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Preoperative anaemia and postoperative outcomes in non-cardiac surgery: a retrospective cohort study
The Lancet, 2011
Background Preoperative anaemia is associated with adverse outcomes after cardiac surgery but outcomes after non-cardiac surgery are not well established. We aimed to assess the eff ect of preoperative anaemia on 30-day postoperative morbidity and mortality in patients undergoing major non-cardiac surgery. Methods We analysed data for patients undergoing major non-cardiac surgery in 2008 from The American College of Surgeons' National Surgical Quality Improvement Program database (a prospective validated outcomes registry from 211 hospitals worldwide in 2008). We obtained anonymised data for 30-day mortality and morbidity (cardiac, respiratory, CNS, urinary tract, wound, sepsis, and venous thromboembolism outcomes), demographics, and preoperative and perioperative risk factors. We used multivariate logistic regression to assess the adjusted and modifi ed (nine predefi ned risk factor subgroups) eff ect of anaemia, which was defi ned as mild (haematocrit concentration >29-<39% in men and >29-<36% in women) or moderate-to-severe (≤29% in men and women) on postoperative outcomes. Findings We obtained data for 227 425 patients, of whom 69 229 (30•44%) had preoperative anaemia. After adjustment, postoperative mortality at 30 days was higher in patients with anaemia than in those without anaemia (odds ratio [OR] 1•42, 95% CI 1•31-1•54); this diff erence was consistent in mild anaemia (1•41, 1•30-1•53) and moderate-to-severe anaemia (1•44, 1•29-1•60). Composite postoperative morbidity at 30 days was also higher in patients with anaemia than in those without anaemia (adjusted OR 1•35, 1•30-1•40), again consistent in patients with mild anaemia (1•31, 1•26-1•36) and moderate-to-severe anaemia (1•56, 1•47-1•66). When compared with patients without anaemia or a defi ned risk factor, patients with anaemia and most risk factors had a higher adjusted OR for 30-day mortality and morbidity than did patients with either anaemia or the risk factor alone. Interpretation Preoperative anaemia, even to a mild degree, is independently associated with an increased risk of 30-day morbidity and mortality in patients undergoing major non-cardiac surgery.
Preoperative Anemia Increases Mortality and Postoperative Morbidity After Cardiac Surgery
Journal of the American College of Cardiology, 2010
Background: Anemia is an established adverse risk factor in cardiovascular disease. However, the effect of preoperative anemia is not well defined in heart surgery. This study evaluates the effect of preoperative anemia on early clinical outcomes in patients undergoing cardiac surgery. Methods: A retrospective, observational, cohort study of prospectively collected data was undertaken on 7,738 consecutive patients undergoing heart surgery between April 2003 and February 2009. Of these, 1,856 patients with preoperative anemia were compared to 5,882 patients without anemia (control group). According to the World Health Organization, anemia was defined as hemoglobin level < 13 g/dl for men and <12 g/dl for women. Selection bias not controlled by multivariable methods was assessed with propensity-adjustment method. Results: Overall mortality was 2.1%. Preoperative anemia was associated with tripling in the risk of death (4.6% vs 1.5%, p < 0.0001) and postoperative renal dysfunction (18.5% vs 6.5%, p < 0.0001). There was also a significant difference between the anemic and non-anemic group in the risk of postoperative stroke (1.9% vs 1.1%, p = 0.008), atrial fibrillation (36.7% vs 33%, p = 0.003) and length of hospital stay > 7 days (54% vs 36.7%, p < 0.0001). In propensity-adjusted, multivariable logistic regression, preoperative anemia was an independent predictor of mortality (odds ratio [OR] 1.44, 95% confidence interval [CI] 1.02 to 2.03), postoperative renal dysfunction (OR 1.73, 95% CI 1.43 to 2.1) and length of hospital stay > 7 days (OR 1.3, 95% CI 1.15 to 1.47). Conclusion: In patients undergoing heart surgery, preoperative anemia is associated with an increased risk of mortality and postoperative morbidity.
IntroductionPreoperative anemia is a common finding among surgical patients. It is associated with an increased risk of perioperative morbidity and mortality. Outcomes among emergency surgical patients are not established. This study aimed to assess the effect of preoperative anemia on perioperative outcomes among patients undergoing emergency surgery in selected Southern Ethiopia governmental teaching hospitals, Southern Ethiopia, 2022.MethodA multicenter prospective cohort study was conducted. Data were collected at selected hospitals, after obtaining ethical approval from the institutional review board. Descriptive statistics, cross-tabulation, and multivariable binary logistic regression analysis were performed. A P-value less than 0.05 were taken as statistically significant.ResultA total of 200 patients who underwent emergency surgery were grouped into the anemia group (100 patients) while the rest were in the non-anemia group. There was no statistically significant difference between the groups regarding socio-demographic and intraoperative patient characteristics. Based on multivariate logistic regression, anemia group had a significant risk of perioperative transfusion requirement (Relative Risk (RR) = 4.030, p < 0.001), developing postoperative complications (RR = 1.868, p = 0.017), occurring in-hospital mortality (RR = 5.763, p = 0.045), prolong the length of hospital stay (RR = 4.028, p < 0.001), and requiring postoperative intensive care unit admission (RR = 6.332, p = 0.003) compared with non-anemia groups.ConclusionPreoperative anemia was associated with a higher rate of perioperative transfusion requirements, along with increased postoperative complication, increased in-hospital mortality, increased Intensive Critical Care Unit admission rate, and prolonged length of hospital stay. We recommend adequate preoperative assessment and correction of hemoglobin concentrations to normal values to improve surgical outcomes and reduce complications.
Anesthesia & Analgesia, 2013
BACKGROUND: Anemia has been associated with increased postoperative morbidity and mortality. We used the American College of Surgeons National Surgical Quality Improvement Program database to retrospectively assess the relationship between preoperative anemia and 30-day postoperative mortality and morbidity in noncardiac surgical patients, careful to distinguish confounding variables from mediator variables. METHODS: Each patient with preoperative anemia was matched to one without anemia using propensity matching on potentially confounding baseline variables. Logistic regression was used to evaluate the relationship between preoperative anemia and 30-day postoperative mortality and morbidity. The primary hypothesis was evaluated after adjusting for covariables showing residual imbalance after matching. RESULTS: Within the database, 574,860 of 971,455 surgical cases met our inclusion criteria, and among those 145,218 (25.3%) were anemic at baseline. The unadjusted odds ratio (95% con dence interval) for 30-day mortality comparing anemic patients with nonanemic patients was 4.69 (4.01-5.49). Among the propensity-matched group of 238,596 patients, the total effect (i.e., not adjusting for mediator variables) of preoperative anemia was estimated as an odds ratio of 1.59 (1.42-1.78). After adjusting for suspected mediator variables, preoperative anemia was only weakly associated with an odds ratio of 1.24 (1.10-1.40) for 30-day mortality. CONCLUSION: Preoperative anemia appears to be associated with baseline diseases that markedly increase mortality. Anemia per se is a rather weak independent predictor of postoperative mortality. Our analysis also illustrates how analyzing large variable-rich registries challenges investigators to discriminate between confounding variables and mediator variables, i.e., factors that might be considered as "causal pathways" for the effect of the exposure or intervention on outcome.
Risk Associated with Preoperative Anemia in Noncardiac Surgery
Anesthesiology, 2009
Background Preoperative anemia is an important risk factor for perioperative red blood cell transfusions and has been shown to be independently associated with adverse outcomes after noncardiac surgery. The objective of this observational study was to measure the prevalence of preoperative anemia and assess the relationship between preoperative anemia and postoperative mortality. Methods Data were retrospectively collected on 7,759 consecutive noncardiac surgical patients at the University Health Network between 2003 and 2006. Preoperative anemia was defined as a hemoglobin concentration less than 12.0 g/dl for women and less than 13.0 g/dl for men. The unadjusted and adjusted relationship between preoperative anemia and mortality was assessed using logistic regression and propensity analyses. Results Preoperative anemia was common and equal between genders (39.5% for men and 39.9% for women) and was associated with a nearly five-fold increase in the odds of postoperative mortality....
Anaesthesia, 2011
Anaemia is increasingly prevalent in the United Kingdom. Despite recommendations to the contrary, many patients undergo cardiac surgery with undiagnosed and untreated anaemia. According to the World Health Organization definition, 1463/2688 (54.4%) patients undergoing cardiac surgery between 2008 and 2009 in our institution were anaemic. Compared with non-anaemic patients, anaemia was significantly associated with transfusion (791 (54.1%) vs 275 (22.4%), p < 0.001, OR (95% CI) 3.4 (2.8-4.1)), death (45 (3.1%) vs 13 (1.1%), p = 0.0005, OR 2.4 (1.2-4.5)), and prolonged ICU stay (287 (19.6%) vs 168 (13.7%) p < 0.001, OR 1.3 (1.0-1.6)). The prevalence of anaemia in this cohort is much greater than that previously reported. The cause of this excess is not clear. Pre-operative anaemia is a strong predictor of increased transfusion requirement, risk of ICU stay and death during cardiac surgery. The effect of increasing haemoglobin concentration therapeutically is not yet clear.
Prevalence and outcomes of anemia in surgery: a systematic review of the literature
American Journal of Medicine, 2004
Untreated preoperative anemia and acute perioperative blood loss may add to surgical risk. To understand the prevalence of anemia in surgical patients (with a primary focus on preoperative anemia), and the impact that preexisting anemia has on transfusion rates as well as on clinical and functional outcomes, a systematic review was performed of articles published between January 1966 and February 2003. The estimates of anemia prevalence in the literature ranged widely, from 5% in geriatric women with hip fracture to 75.8% in patients with Dukes stage D colon cancer. Diagnosis of anemia was most strongly associated with an increased risk of receiving an allogeneic transfusion. In general, patients who donated autologous blood preoperatively received less allogeneic blood than those who did not donate. There was some suggestion that lower hemoglobin levels are associated with decreased survival rates, although this was not found universally. Too few studies were found that evaluated the impact of anemia on other outcomes, such as functional status and costs and resource utilization, to draw reliable conclusions. Several other factors also limited the interpretation of the data, including the lack of a uniform definition for anemia and a dearth of studies expressly designed to quantify the prevalence and impact of anemia. Establishing a uniform definition and specifically evaluating the effect of anemia on outcomes are important considerations for future study. Am J Med. 2004;116(7A):58S-69S.
Transfusion Alternatives in Transfusion Medicine, 2010
Preoperative anemia in patients undergoing cardiac surgery is associated with a higher transfusion risk and poorer outcomes. This retrospective study was undertaken to assess the prevalence of preoperative anemia and its associated risk factors, as well as its influence on postoperative outcomes, in 576 patients undergoing elective cardiac surgery (52.3% with cardiopulmonary bypass) for myocardial revascularization, valve replacement, coronary + valve, or miscellaneous pathology at a single institution. Perioperative data were reviewed according to the presence or absence of preoperative anemia (hemoglobin < 13 g/dL for men, hemoglobin < 12 g/dL for women). Overall, 210 patients (36.5%) presented with anemia. Logistic regression analysis revealed that age, chronic kidney disease, and consumption of proton pump inhibitors histamine H2 receptor antagonists and diuretics were independent risk factors for the presence of preoperative anemia. Postoperatively, anemic patients received transfusions and inotropic support and stayed longer than 4 days in the recovery unit more frequently than non-anemic patients, but there were no differences in the composite outcome variable (stroke, myocardial infarction, renal failure or death). In conclusion, our data seem to indicate that preoperative anemia has a high prevalence among elective cardiac surgical patients and increases postoperative morbidity. Therefore, we need to address two specific areas about preoperative anemia in these patients: early recognition and evaluation, and appropriate and timely treatment.