A clinical scenario-based survey of transfusion decisions for intensive care patients with delayed weaning from mechanical ventilation.

BACKGROUND: Despite evidence supporting the use of restrictive hemoglobin (Hb) transfusion triggers in critically ill patients, translation of this evidence into practice remains inconsistent. It was hypothesized that clinicians believe that longer-term ventilated patients require a higher Hb, particularly when ischemic heart disease coexists. STUDY DESIGN AND METHODS: A scenario was developed describing an anemic patient recovering from multiple organ failure, but failing weaning trials after 6 days of mechanical ventilation. Clinicians were asked to state their Hb transfusion trigger and target Hb range assuming no history of ischemic heart disease (Scenario 1), known stable chronic ischemic heart disease (Scenario 2), or evidence of myocardial ischemia during weaning trials (Scenario 3). A prospective cross-sectional postal survey of clinicians practicing intensive care in the United Kingdom was undertaken. RESULTS: A total of 184 responses were obtained (52% response rate), which varied widely. Median (first, third quartile) transfusion trigger Hb levels were 8 (7, 8), 9 (8, 9.5), and 9.5 (9, 9.5) g/dL for Scenarios 1 to 3, respectively (p < 0.001 across and between each group). The target Hb was more than 9 g/dL for 47, 80, and 94% of respondents for Scenarios 1 to 3, respectively, and more than 10 g/dL for 14, 44, and 65% of respondents for Scenarios 1 to 3, respectively (p < 0.001 across the groups). CONCLUSIONS: In response to scenarios, clinicians in the United Kingdom believe that a more liberal transfusion practice is required for patients failing weaning trials after 6 days of mechanical ventilation than the current evidence base supports.

Anemia during and at discharge from intensive care: the impact of restrictive blood transfusion practice.

OBJECTIVE: To document the prevalence of anemia among patients admitted to intensive care (ICU) and, among survivors, at ICU discharge when restrictive transfusion practice was used. DESIGN: This was an observational cohort study. SETTING: Ten of the 26 general ICUs in Scotland. PATIENTS AND PARTICIPANTS: One thousand twenty-three sequential ICU admissions over 100 days, representing 44% of all ICU admissions in Scotland during the study period, studied daily from admission to discharge or death in the ICU. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: The median transfusion trigger used, in the absence of bleeding, was 78 g/l (interquartile range 73-84); <2% of transfusion triggers were above the upper limit of the national transfusion trigger guideline (100 g/l). Overall, 25% of admissions had a hemoglobin concentration <90 g/l at ICU admission. Seven hundred sixty-six patients admitted survived to ICU discharge. Among these, the prevalence of anemia (male <130 g/l; female <115 g/l) at ICU discharge was 87.0 (95% CI: 83.6 to 89.9)% for males and 79.6 (74.8 to 83.7)% for females. Of the male survivors 24.1 (20.3 to 28.3)% and of the female 27.9 (23.4 to 33.2)% had a hemoglobin <90 g/l at ICU discharge. The prevalence was similar for patients with and without pre-existing ischemic heart disease. Logistic regression found independent associations between having a hemoglobin concentration <90 g/l at ICU discharge and the first measured hemoglobin in ICU, the presence of acute renal failure and thrombocytopenia during ICU stay. CONCLUSIONS: Anemia is highly prevalent in ICUs that use restrictive transfusion triggers. The impact of anemia on functional recovery after intensive care requires investigation.