article172

TRICC

"Restrictive versus Liberal Transfusion Strategy in Critically Ill Patients". The New England Journal of Medicine. 1999. 340(6):409-417. PubMed • Full text • PDF

1 Clinical Question
2 Bottom Line
3 Major Points
4 Guidelines
5 Design
6 Population
6.1 Inclusion Criteria
6.2 Exclusion Criteria
6.3 Baseline Characteristics
7 Interventions
8 Outcomes
8.1 Primary Outcomes
8.2 Secondary Outcomes
9 Criticisms
10 Funding
11 Further Reading

Clinical Question

In critically ill patients, does a restrictive strategy of red-cell transfusion (maintaining hemoglobin 7.0 to 9.0 g per deciliter) compared with a liberal strategy (maintaining hemoglobin 10.0 to 12.0 g per deciliter) affect 30-day mortality?

Bottom Line

A restrictive transfusion strategy maintaining hemoglobin levels between 7.0 to 9.0 g per deciliter in critically ill patients was at least as effective as and possibly superior to a liberal transfusion strategy, potentially reducing the average number of red-cell units transfused and 30-day mortality.

Major Points

Previous strategies involving liberal red-cell transfusions in critically ill patients to augment oxygen delivery were challenged by concerns over potential transfusion-related complications and the scarcity of blood. The study compared the effects of maintaining lower (7.0 to 9.0 g per deciliter) versus higher (10.0 to 12.0 g per deciliter) hemoglobin levels in critically ill patients and found that a restrictive approach to red-cell transfusion may be superior in reducing mortality rates and associated complications.

Guidelines

Current guidelines may reflect on the results of this study by recommending a more conservative approach to transfusions in critically ill patients, with specific considerations for individual clinical circumstances.

Design

- Multicenter, randomized, controlled clinical trial
- N=838 critically ill patients with euvolemia and hemoglobin <9.0 g per deciliter within 72 hours after ICU admission
- Restrictive strategy (n=418): Transfusion if hemoglobin <7.0 g per deciliter (target 7.0-9.0 g per deciliter)
- Liberal strategy (n=420): Transfusion if hemoglobin <10.0 g per deciliter (target 10.0-12.0 g per deciliter)
- Setting: 25 hospitals in Canada
- Enrollment: November 1994 to November 1997
- Analysis: Intention-to-treat
- Primary outcome: Mortality from any cause at 30 days

Population

Inclusion Criteria: Critically ill patients expected to stay in ICU >24 hours, with hemoglobin concentration ≤9.0 g per deciliter within 72 hours of ICU admission, considered euvolemic after initial treatment.

Exclusion Criteria: Age <16 years, refusal of blood products, active blood loss at enrollment, chronic anemia, pregnancy, brain death, treatment withholding or withdrawal decisions, post-routine cardiac surgery.

Baseline Characteristics: Similar between groups, average age 57.6 years, average APACHE II score 21, majority on mechanical ventilation, and common admission reasons were respiratory and cardiac diseases.

Interventions

- Patients managed according to the transfusion strategy to which they were assigned during their ICU stay.
- Suggestions for use of fluids and vasoactive drugs provided.
- Other management decisions left to discretion of physicians.

Outcomes

Primary Outcomes: 30-day mortality was 18.7% in the restrictive-strategy group compared to 23.3% in the liberal-strategy group (P=0.11).

Secondary Outcomes:
- Hospitalization mortality was lower in the restrictive-strategy group (22.2% vs. 28.1%, P=0.05).
- Rates of multiorgan failure did not significantly differ between groups.
- 60-day mortality, ICU mortality, and survival time in the first 30 days showed no significant differences.
- Rates of cardiac complications favored the restrictive strategy (P<0.01).

Criticisms

- Potential impact of noncompliance with transfusion protocols and physician crossover between treatment groups on the results.
- While representing a variety of critical illnesses, the trial excluded certain patient populations, thus limiting the generalizability of findings to all critically ill patients.

Funding

Supported by the Medical Research Council of Canada and an unrestricted grant from Bayer. Dr. Hébert is a Career Scientist of the Ontario Ministry of Health.