Hemoglobin Levels Following Aeromedical Evacuation as Related to Postflight Surgery in Extremity Wounds
Abstract
This research sought a hemoglobin level (aka cut point) below which postflight extremity surgical revision or amputation was inevitable, a point demanding transfusion prior to aeromedical evacuation (AE). Ninety battle injured Canadian AE patients (January 2009 through August 2011) were studied. The DAFI 48-107Vol1 suggested a cut point of </= 8 g/dl; postflight surgical rates proved significantly higher in the </= 8 g/dl patients. However, surgical rates were also significantly higher with other </= cut points. Indeed, Receiver Operating Characteristic (ROC) curve analyses affirmed hemoglobin a poor-quality marker for both surgical outcomes. Surgery rates at < 8 g/dl (extremity surgical revision) and </= 9 g/dl (amputation) appeared to overly influence the other cut point surgery rates, perhaps explaining the poor ROC performance. Correlational and linear regression analyses demonstrated a significant inverse dose-response relationship between hemoglobin level and surgery. This relationship was corroborated with a highly significant logistic regression model. In short, both the rates of and the probability for postflight surgery dropped as the hemoglobin level rose. Multivariate predictive modelling (recursive partitioning and logistic regression methodologies) defined several factors upping the probability of postflight surgery and two factors dropping that probability. In summary, though no well-defined hemoglobin cut point was found, a number of invaluable findings were discovered that when combined with tissue oxygen delivery tenets offer up a logical and coherent approach for the Theater Validating Flight Surgeon seeking to validate for AE a casualty/patient with acute anemia.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 04, 2022
- Accession Number
- AD1163245
Entities
People
- G. M. Rice
- Richard R. Hannah
- Robert H. Jr Galavan
- William P. Butler
Organizations
- 711th Human Performance Wing
- Canadian Armed Forces
- Naval Aerospace Medical Institute