Iron Deficiency Anemia in Children During and After PICU Stay: Single-Center Retrospective Cohort, 2021-2022

Abstract

Objectives: The primary objective was to determine iron deficiency (ID) anemia (IDA) monitoring practices in children during PICU stay. A secondary objective was to determine the current follow-up practices for IDA after PICU discharge.

Design: Retrospective observational study of 2 years (2021-2022).

Setting: Single-center academic PICU in the United States.

Subjects: All patients younger than 18 years and excluded patients who died in the PICU or within 6 months of PICU discharge.

Interventions: None.

Measurements and main results: Anemia was defined by a hemoglobin concentration of less than 11 g/dL. ID was defined by either a ferritin of less than 30 ng/mL or a transferrin saturation (TSAT) of less than or equal to 20%. Suspicion for functional iron deficiency (SID) was defined by ferritin greater than or equal to 30 ng/mL and TSAT less than or equal to 20%, given the hyperferritinemic effect of inflammation. We documented serum iron, total iron binding capacity, TSAT, ferritin, and hemoglobin at PICU admission and discharge and 3 and 6 months after discharge. Overall, 913 of 1275 met the inclusion criteria, and 492 patients had a hemoglobin of less than 11 g/dL. Only 93 of 492 (18.9%) had iron studies at any time during the PICU stay. Among the 93 patients with iron studies, 20 patients (22%) were lost to follow-up. Of the remaining 73 patients, 67 of 73 had a hemoglobin checked at 3 months, of which 37 of 67 (55%) were still anemic. At 6 months, there were 64 of 73 patients who had a hemoglobin checked, of which 32 of 64 (50%) were still anemic. At 3 months, 39 of 73 (53%) had iron studies performed; of these, 13 of 39 had ID, 12 of 39 had SID, and 14 of 39 had neither ID nor SID. At 6 months, 35 of 73 (48%) had iron studies; of these, ten of 35 had ID, 11 of 35 had SID, and 14 of 35 had neither ID nor SID.

Conclusions: Detection of ID and follow-up after PICU stay remain inadequate. We recommend that future studies assess the value of screening all critically ill patients for ID at the time of discharge and followed up, as necessary.