[Follow-up hemoglobin concentrations in ICU: relationship between diagnostic blood loss and daily fluid balance]

To evaluate DeltaHb (daily changes of hemoglobin concentrations) in nonbleeding critically ill patients, and to investigate its relation with diagnostic blood loss (DBL) and fluid balance (FB). Hospital records of 34 nonseptic patients who stayed in respiratory intensive care unit (RICU) at least 72 hours with no evidence of acute bleeding, renal failure and bleeding diathesis, were evaluated retrospectively. Demographics, clinical features, acute physiology assessment and chronic health evaluation (APACHE) II scores, daily Hb levels, DBL and FB were recorded. Correlation statistics was performed between DeltaHb and DBL and FB. We compared the patients with DeltaHb > or =0.5 g/dL/day (group A) and the patients with DeltaHb < 0.5 g/dL/day (group B) in the first three days. The mean age was 55 +/- 14, Hb level was 13.2 +/- 1.7 g/dL at admission and 12.6 +/- 2.3 g/dL at discharge from RICU. DBL was 25.2 +/- 7.4 mL/d, and FB was 251 +/- 1783 mL/d for the first day in intensive care unit. DBL was lesser in subsequent days than in the first day but it wasn't significant. DeltaHb was -0.54 +/- 1.5 g/dL for the first three days, while it was -0.23 +/- 1.5 g/dL for subsequent four days (p= 0.9). DeltaHb in the first three days has no correlation with DBL and FB. Age, sex, APACHE II score, clinical features, DBL and FB were not differed between Group A and Group B.

No relation was found between DeltaHb and DBL, and also FB; but studies like this are important to indicate that Hb concentrations may decrease in critically ill patients without any reason such as bleeding.