Association of Preoperative Anemia With Postoperative Mortality in Neonates

Abstract

IMPORTANCE Neonates undergoing noncardiac surgery are at risk for adverse outcomes. Preoperative anemia is a strong independent risk factor for postoperative mortality in adults. To our knowledge, this association has not been investigated in the neonatal population. OBJECTIVE To assess the association between preoperative anemia and postoperative mortality in neonates undergoing noncardiac surgery in a large sample of US hospitals. DESIGN, SETTING, AND PARTICIPANTS Using data from the 2012 and 2013 pediatric databases of the American College of Surgeons National Surgical Quality Improvement Program, we conducted a retrospective study of neonates undergoing noncardiac surgery. Analysis of the data took place between June 2015 and December 2015. All neonates (0-30 days old) with a recorded preoperative hematocrit value were included. EXPOSURES Anemia defined as hematocrit level of less than 40%. MAIN OUTCOMES AND MEASURES Receiver operating characteristics analysis was used to assess the association between preoperative hematocrit and mortality, and the Youden J Index was used to determine the specific hematocrit cutoff point to define anemia in the neonatal population. Demographic and postoperative outcomes variables were compared between anemic and nonanemic neonates. Univariate and multivariable logistic regression analyses were used to determine factors associated with postoperative neonatal mortality. An external validation was performed using the 2014 American College of Surgeons National Surgical Quality Improvement Program database. RESULTS Neonates accounted for 2764 children (6%) in the 2012-2013 American College of Surgeons National Surgical Quality Improvement Program databases. Neonates inlcuded in the study were predominately male (64.5%), white (66.3%), and term (69.9% greater than 36 weeks' gestation) and weighed more than 2 kg (85.0%). Postoperative in-hospital mortality was 3.4% in neonates and 0.6% in all age groups (0-18 years). A preoperative hematocrit level of less than 40% was the optimal cutoff (Youden) to predict in-hospital mortality. Multivariable regression analysis demonstrated that preoperative anemia is an independent risk factor for mortality (OR, 2.62; 95% CI, 1.51-4.57) in neonates. The prevalence of postoperative in-hospital mortality was significantly higher in neonates with a preoperative hematocrit level less than 40%; being 7.5% (95% CI, 1%-10%) vs 1.4% (95% CI, 0%-4%) for preoperative hematocrit levels 40%, or greater. The relationship between anemia and in-hospital mortality was confirmed in our validation cohort (National Surgical Quality Improvement Program 2014). CONCLUSIONS AND RELEVANCE To our knowledge, this is the first study to define the incidence of preoperative anemia in neonates, the incidence of postoperative in-hospital mortality in neonates, and the association between preoperative anemia and postoperative mortality in US hospitals. Timely diagnosis, prevention, and appropriate treatment of preoperative anemia in neonates might improve survival.

Society for the advancement of blood management administrative and clinical standards for patient blood management programs. 4th edition (pediatric version)

“…Metabolic rate and baseline oxygen demands may be greater than in adults. However, otherwise healthy pediatric age patients (excluding neonates for which there is a paucity of data) may be more tolerant of severe anemia than critically ill children or those with pre‐existing medical conditions with compromised cardiopulmonary function, and may tolerate lower hemoglobin transfusion thresholds, particularly when anemia develops slowly …”

“…The impact of preoperative anemia on postoperative patient outcomes has been reported. Preoperative anemia is independently associated with increasing the risk of requiring a blood transfusion and increasing postoperative morbidity and mortality in surgical and critically ill pediatric patients . Given that preoperative anemia is a significant health problem and that it has a strong independent association with mortality in neonates, infants and children, outcomes may be improved by timely preoperative screening, diagnosis, prevention and appropriate monitoring and treatment.…”

Preoperative Anemia and Neonates

“…If these critically ill neonates had an increase in their Hct prior to surgery, would their survival improve? The information provided by Goobie et al 1 is cer tainly thought provoking. It is hypothesis-generating observational data that suggest optimizing preoperative Hct may improve post-operative survival, particularly in neonates who weigh less than 2 kg, are on mechanical ventilation prior to surgery, or are receiving inotropic medication prior to surgery.…”

“…In this issue, Goobie et al 1 describe an independent association of preoperative anemia, defined as a hematocrit (Hct) level less than 40%, with higher in-hospital mortality in neonates. Preoperative anemia was 1 of several independent risk factors associated with postoperative mortality; the others were American Society of Anesthesiologists class 3 to 5, body weight less than 2 kg, preoperative mechanical ventilation, and preoperative inotropic support.…”

“…The work of Goobie et al 1 has shone a spotlight on this understudied population and the lack of data to guide RBC transfusion practices. However, in their study, was it the anemia or the conditions that led to the anemia that were associated with a higher surgical mortality in the neonate?…”