Tissue Oxygenation, Anemia, and Perfusion in Relation to Wound Healing in Surgical Patients

TLDR

Oxygen is essential for healing but reparative tissue consumes only a small fraction of it. The study measured oxygen tension and collagen deposition in 33 postoperative surgical wounds and analyzed clinical parameters using correlation and regression methods. Collagen deposition and wound tensile strength are directly limited by perfusion and tissue oxygen tension, with no significant association to hematocrit or other clinical variables, indicating that maintaining high peripheral perfusion can compensate for anemia without normalizing hemoglobin.

Abstract

Oxygen tension and collagen deposition were measured in standardized, subcutaneous wounds in 33 postoperative surgical patients. Pertinent clinical and wound parameters were analyzed by Pearson's correlation test and sequential linear regression analysis. Collagen deposition was directly and significantly proportional to wound oxygen tension and measures of perfusion. There were no significant correlations with hematocrit, estimated blood loss, length of operation, smoking, age, weight, sex, or urine output. This study in humans confirms animal experiments showing that collagen deposition and tensile strength in wounds are limited by perfusion and tissue oxygen tension. It appears unnecessary to maintain hemoglobin at normal levels to support repair, provided that peripheral perfusion can be maintained at a high level in compensation for anemia. These circumstances reflect the fact that although oxygen is essential to many aspects of healing, and must be delivered at adequate partial pressures, reparative tissue consumes relatively little of it.