Comparison of available oxygen before and after red blood cell transfusion in critically-ill premature newborn infants of 28-36 weeks gestational age, to asses its possible usefulness in clinical practice.

BACKGROUND

Wardrop's formula to estimate available oxygen has been used to assess non-critically ill pre-term newborn infants (PTNIs) of 28-32 weeks gestational age who may need red blood cell transfusion ( RBCT ). The use of this formula has not been analyzed in critically-ill PTNIs. The objective of this study was to compare available oxygen levels before and after RBCTs in critically-ill PTNIs of 28-36 weeks gestational age, and to assess is potential usefulness.

MATERIAL AND

METHODS

113 clinical charts of critically-ill PTNIs with at least one RBCT performed between January 1998 and August 2001 were retrospectively reviewed. Hemoglobin concentrations, available oxygen levels and clinical signs of anemia (tachycardia, polypnea, pallor, failure to gain weight) were measured 3 days before, at the moment and 24-72 hours after the RBCT. Descriptive and inferential statistics were used to analyze the results. Statistical significance was considered when p < 0.05.

RESULTS

Mean available oxygen levels were 7.99 +/- 1 mL/dL at the moment of the first RBCT (n = 113), 7.91 +/- 0.91 mL/dL at the second (n = 48), and 8.14 +/- 0.83 mL/dL at the third RBCT (n = 22). Available oxygen was significantly higher 24-72 hours after than before all RBCTs (p < 0.01). The mean available oxygen value at the moment of the first, second and third RBCTs was always near 8 mL/dL.

CONCLUSIONS

Available oxygen is a good parameter to assess the need for RBCTs in critically-ill PTNIs of 28-36 weeks gestational age. Available oxygen values < 8mL/dL may be another parameter to consider as a criterion for RBCT in these patients.