title: Impact of Delta Hemoglobin on Provider Transfusion Practices and Post-operative Morbidity Among Patients Undergoing Liver and Pancreatic Surgery.
abstract: Delta hemoglobin (ΔHb) is defined as the difference between the preoperative Hb and the lowest post-operative Hb level. We sought to define the impact of ΔHb relative to nadir Hb levels on the likelihood of transfusion, as well as characterize the impact of ΔHb and nadir Hb on morbidity among a large cohort of patients undergoing complex hepatopancreatobiliary (HPB) surgery.
  
  
  
  Patients who underwent pancreatic or hepatic resection between January 1, 2009 and June 30, 2015 at Johns Hopkins Hospital were identified. Data on the perioperative ΔHb, nadir Hb, as well as blood utilization were obtained and analyzed. Multivariable logistic regression models were used to identify the factors associated with ΔHb and the impact of ΔHb on perioperative morbidity. A Bayesian model was used to evaluate the correlation of ΔHb and nadir Hb with the likelihood of transfusion, as well as the impact on morbidity.
  
  
  
  A total of 4363 patients who underwent hepatobiliary (n = 2200, 50.4 %) or pancreatic (n = 2163, 49.6 %) surgery were identified. More than one quarter of patients received at least one unit of packed red blood cells (PRBC) (n = 1187, 27.2 %). The median nadir Hb was 9.2 (IQR 7.9-10.5) g/dL resulting in an average ΔHb of 3.4 mg/dL (IQR 2.2-4.7) corresponding to 26.3 %. Both ΔHb and nadir Hb strongly influenced provider behavior with regards to use of transfusion. Among patients with the same nadir Hb, ΔHb was strongly associated with use of transfusion; among patients who had a nadir Hb ≤6 g/dL, the use of transfusion was only 17.9 % when the ΔHb = 10 % versus 49.1 and 80.9 % when the ΔHb was 30 or 50 %, respectively. Perioperative complications occurred in 584 patients (13.4 %) and were more common among patients with a higher value of ΔHb, as well as patients who received PRBC (both P < 0.001).
  
  
  
  The combination of the Hb trigger with ΔHb was associated with transfusion practices among providers. Larger ΔHb values, as well as receipt of transfusion, were strongly associated with risk of perioperative complication following HPB surgery.
authors.affiliation: The Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Gaya
authors.initials: G
authors.lastname: Spolverato
authors.affiliation: The Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Fabio
authors.initials: F
authors.lastname: Bagante
authors.affiliation: The Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Matthew
authors.initials: M
authors.lastname: Weiss
authors.affiliation: The Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Jin
authors.initials: J
authors.lastname: He
authors.affiliation: The Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Christopher L
authors.initials: CL
authors.lastname: Wolfgang
authors.affiliation: The Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Fabian
authors.initials: F
authors.lastname: Johnston
authors.affiliation: The Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Martin A
authors.initials: MA
authors.lastname: Makary
authors.affiliation: The Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Will
authors.initials: W
authors.lastname: Yang
authors.affiliation: The Department of Anesthesia and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Steven M
authors.initials: SM
authors.lastname: Frank
authors.affiliation: The Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA. tim.pawlik@osumc.edu.|The Urban Meyer III and Shelley Meyer Chair in Cancer Research, Chair Department of Surgery, The Ohio State University Wexner Medical Center, Columbus, OH, USA. tim.pawlik@osumc.edu.
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Pawlik
mesh_terms: D000368:Aged; D001499:Bayes Theorem; D015331:Cohort Studies; D017707:Erythrocyte Transfusion / Q000706:statistics & numerical data*; D005260:Female; D006454:Hemoglobins / Q000378:metabolism*; D006498:Hepatectomy / Q000009:adverse effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010180:Pancreatectomy / Q000009:adverse effects*; D011184:Postoperative Period; D010818:Practice Patterns, Physicians'; D057234:Preoperative Period
chemical_list: D006454:Hemoglobins
keywords: Delta; Hemoglobin; Hepatopancreatobiliary; Outcomes; Surgery