The CRIT Study: Anemia and blood transfusion in the critically ill--current clinical practice in the United States.
OBJECTIVE
To quantify the incidence of anemia and red blood cell (RBC) transfusion practice in critically ill patients and to examine the relationship of anemia and RBC transfusion to clinical outcomes.


METHODS
Prospective, multiple center, observational cohort study of intensive care unit (ICU) patients in the United States. Enrollment period was from August 2000 to April 2001. Patients were enrolled within 48 hrs of ICU admission. Patient follow-up was for 30 days, hospital discharge, or death, whichever occurred first.


METHODS
A total of 284 ICUs (medical, surgical, or medical-surgical) in 213 hospitals participated in the study.


METHODS
A total of 4,892 patients were enrolled in the study.


RESULTS
The mean hemoglobin level at baseline was 11.0 +/- 2.4 g/dL. Hemoglobin level decreased throughout the duration of the study. Overall, 44% of patients received one or more RBC units while in the ICU (mean, 4.6 +/- 4.9 units). The mean pretransfusion hemoglobin was 8.6 +/- 1.7 g/dL. The mean time to first ICU transfusion was 2.3 +/- 3.7 days. More RBC transfusions were given in study week 1; however, in subsequent weeks, subjects received one to two RBC units per week while in the ICU. The number of RBC transfusions a patient received during the study was independently associated with longer ICU and hospital lengths of stay and an increase in mortality. Patients who received transfusions also had more total complications and were more likely to experience a complication. Baseline hemoglobin was related to the number of RBC transfusions, but it was not an independent predictor of length of stay or mortality. However, a nadir hemoglobin level of <9 g/dL was a predictor of increased mortality and length of stay.


CONCLUSIONS
Anemia is common in the critically ill and results in a large number of RBC transfusions. Transfusion practice has changed little during the past decade. The number of RBC units transfused is an independent predictor of worse clinical outcome.
Corwin
Howard L
HL
Dartmouth-Hitchcock Medical Center, Lebanon, NH 03756, USA. howard.l.corwin@hitchcock.org
Gettinger
Andrew
A
Pearl
Ronald G
RG
Fink
Mitchell P
MP
Levy
Mitchell M
MM
Abraham
Edward
E
MacIntyre
Neil R
NR
Shabot
M Michael
MM
Duh
Mei-Sheng
MS
Shapiro
Marc J
MJ
D000328:Adult; D000368:Aged; D000740:Anemia / Q000175:diagnosis / Q000401:mortality / Q000628:therapy*; D001774:Blood Chemical Analysis; D001803:Blood Transfusion / Q000592:standards / Q000706:statistics & numerical data; D015331:Cohort Studies; D016001:Confidence Intervals; D003422:Critical Care / Q000379:methods / Q000592:standards; D016638:Critical Illness / Q000628:therapy*; D017707:Erythrocyte Transfusion / Q000592:standards* / Q000706:statistics & numerical data; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010818:Practice Patterns, Physicians'; D011336:Probability; D011446:Prospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D016019:Survival Analysis; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology