1. Monthly Journal article review: Vimmi Kang PGY 2
The New England Journal of Medicine: A Multicenter, Randomized, Controlled Clinical Trial of Transfusion Requirements in Critical Care
Monthly Journal article review:
Vimmi Kang PGY 2

2. Importance
Transfusions are a necessary part of managing critical patients.
Different views of when to transfuse in regards to risks versus benefits
Microcirculatory and immunosuppressive complications of red cell transfusions
Concern about supply and safety of blood
Two recent studies suggested that anemia increases risk of death in patients with cardiac disease and in critical ill patients
Prompted the routine use of transfusion in hgb>10g/dL
Optimal transfusion practice for various types of critically ill patients with anemia has not been established

3. Background
To determine whether a restrictive strategy of red cell transfusion and a liberal strategy produced equivalent results in critically ill patients.
Rates of death from all causes at 30 days and the severity of organ dysfunction was compared between the two groups.

4. Enrolled patients in Canada between November 1994 and November 1997
Study was published in 1999
Enrolled patients in Canada between November 1994 and November 1997
Exclusion criteria
Age less than 16yrs
Inability to receive blood products
Active blood loss at the time of enrollment
Requirement of >3prbc OR
Decrease in hgb by 3 in the preceding 12 hours
Chronic anemia (hgb <9)
At least one occasion more than 1 month prior to hospital admission
Pregnancy
Brain death or imminent death (within 24hrs)
Question on the part of attending physicians whether to withhold or withdraw ongoing treatment
Admission after a routine cardiac procedure

5. Method
Enrolled 838 critically ill patients with euvolemia after initial treatment, with hemoglobin conc of less than 9 g/dL within 72 hours of admission to the ICU
418 of those were randomly assigned to the restrictive group
420 patients to the liberal group

7. Restrictive Strategy of transfusion
RBC were transfused if hemoglobin concentration dropped <7.0g/dL
Hemoglobin concentration was maintained at 7 to 9 g/dL

8. Liberal Strategy of red cell transfusion
Transfusion was given if hemoglobin concentrations fell below 10g/dL
Hemoglobin concentrations were maintained at 10 to 12 g/dL

9. Base Line Characteristics of the Study Patients

10. Hgb was measured after each unit of transfusion APACHE II
Assessed on the day of admission to the ICU
Scores range from 0 to 71
MODS
Scores range from 0 to 24

11. Outcome measures Primary outcome Secondary outcome
Death from all causes in 30 days
Secondary outcome
60 day rates of death
Mortality rates during ICU stay
Mortality rated during hospitialization
Measures of organ failure and dysfunction

12. Outcomes

13. Results 30 day mortality between the two groups were similar
18.7% vs 23.3%
Exceptions
Rates were significantly lower in the restrictive group among patients who had a score <20 in Acute Physiology and Chronic Health Evaluation II
8.7% vs 16.1%
Among patient less than 55yrs of age
5.7% vs 13%
But not among patients with significant cardiac disease
20.5% vs 22.9%
Mortality rate during hospitalization was significantly lower in the restrictive strategy group
22.2% vs 28.1%

17. Cardiac events, primarily pulmonary edema and Myocardial infarction were more frequent in the liberal-strategy group than in the restrictive strategy group during ICU stay

18. Conclusions
Restrictive strategy of red cell transfusion is at least as effective as and possibly superior to a liberal transfusion strategy in critically ill patients with the possible exception of patients with acute myocardial infarction and unstable angina

19. critique
Hypothesis: oxygen delivery should be increased or maintained at high levels to minimize the effects of tissue hypoxis caused by disease processes that interfere with oxygen delivery or the body ability to extract oxygen
Many randomized, controlled clinical trials addressed this hypothesis
Trials did not make inferences on the optimal strategy for red cell transfusion

20. Results from previous studies were not correlated with this study
“Increasing severity of anemia was associated with a disproportionate increase in mortality rates among patients with ischemic heart disease”
However with this study, it did not show increase in mortality or adverse outcomes in patients with cardiac disease under the restrictive transfusion group when compared to the liberal group
Greater proportion of patients that ‘refused’ to be included this study were of the cardiac disease category
Attending physicians
Can affect generalization of the results, especially myocardial infarction and angina
Not enough data to make any generalization

21. Did not adhere to the liberal vs restrictive strategy once patient was transferred out of ICU
What affect does that have on the secondary outcomes