Empty iron stores as a significant risk factor in abdominal surgery.

The mortality and morbidity in abdominal surgery were investigated in two groups of patients, one with empty (N = 228) and the other with normal (N = 220) iron stores before operation. The estimation of body iron stores by measurements of serum ferritin concentration assumes that the only reason for a low ferritin value is an empty iron store. The results showed that the period of hospital treatment was shorter and the number of complications, especially infections, fewer, in patients with normal as compared to empty iron stores before the operation (p less than 0.001). These differences were especially striking in patients subjected to gastric or large bowel surgery. The results were not explained by differences in sex, age, serum albumin, or clinical anemia. The complications were not predictable from preoperative serum albumin, alkaline phosphatase, or alanine amino transferase levels. Among patients with postoperative complications those with preoperative empty iron stores also had a lower preoperative blood hemoglobin concentration (127 +/- 10 g/liter) than those with normal preoperative iron stores (136 +/- 9 g/liter). Thus it is speculated that the mechanisms behind postoperative complications due to preoperative empty iron stores might be a decrease in tissue oxygenation, resulting in an increased fatigue while working, decreased contractile capacity of the respiratory muscles, and a decrease in immune function. Thus a measurement of serum ferritin concentration and correction of empty iron stores is recommended before abdominal surgery.