BACKGROUND The optimal transfusion threshold after surgery in children is unknown. We analyzed the general surgery subgroup of the TRIPICU (Transfusion Requirements in Pediatric Intensive Care Units) study to determine the impact of a restrictive versus a liberal transfusion strategy on new or progressive multiple organ dysfunction syndrome (MODS). METHODS The TRIPICU study, a prospective randomized controlled trial conducted in 17 centers, enrolled a total of 648 critically ill children with a hemoglobin equal to or below 9.5 g/dL within 7 days of pediatric intensive care unit (PICU) admission to receive prestorage leukocyte-reduced red-cell transfusion if their hemoglobin dropped below either 7.0 g/dL (restrictive) or 9.5 g/dL (liberal). A subgroup of 124 postoperative patients (60 randomized to restrictive and 64 to the liberal group) were analyzed. This study was registered at http://www.controlled-trials.com and carries the following ID ISRCTN37246456. RESULTS Participants in the restrictive and liberal groups were similar at randomization in age (restrictive vs. liberal: 53.5 +/- 51.8 vs. 73.7 +/- 61.8 months), severity of illness (pediatric risk of mortality [PRISM] score: 3.5 +/- 4.0 vs. 4.4 +/- 4.0), MODS (35% vs. 29%), need for mechanical ventilation (77% vs. 74%), and hemoglobin level (7.7 +/- 1.1 vs. 7.9 +/- 1.0 g/dL). The mean hemoglobin level remained 2.3 g/dL lower in the restrictive group after randomization. No significant differences were found for new or progressive MODS (8% vs. 9%; P = 0.83) or for 28-day mortality (2% vs. 2%; P = 0.96) in the restrictive versus liberal group. However, there was a statistically significant difference between groups for PICU length of stay (7.7 +/- 6.6 days for the restrictive group vs. 11.6 +/- 10.2 days for the liberal group; P = 0.03). CONCLUSIONS In this subgroup analysis of pediatric general surgery patients, we found no conclusive evidence that a restrictive red-cell transfusion strategy, as compared with a liberal one, increased the rate of new or progressive MODS or mortality.