Search

Objective: To see whether there was a link between blood transfusion and lipid peroxidation as measured by urinary malondialdehyde (MDA) concentration in preterm infants., Methods: Urine samples were collected before and after blood transfusions in preterm infants. Twenty blood transfusion episodes were studied in 12 infants (some infants were studied on more than one occasion). Twenty two infants who had not received a transfusion were used as controls. All infants were preterm and less than 1500 g birth weight. Urinary MDA was measured using a thiobarbituric acid assay and expressed as nmol/mg creatinine., Results: The median (interquartile range) urinary MDA concentration before transfusion was 9.1 (6.4-12.6) nmol/mg, and was not significantly different from that in the 22 non-transfused infants (11.3 (7.3-15.6) nmol/mg). There was a significant increase 24 hours after transfusion to 14.6 (7.3-23.7) nmol/mg, but it decreased to 10.1 (6.6-15.4) nmol/mg when measured a median (range) of 6 (3-9) days later., Conclusions: Blood transfusions were associated with evidence of increased lipid peroxidation. If lipid peroxidation contributes to the pathogenesis of retinopathy of prematurity and chronic lung disease, these results suggest an explanatory mechanism.

Background: Peripheral fractional oxygen extraction (FOE) may be a better indicator of the need for transfusion than the haemoglobin concentration (Hb) because it is a measure of the adequacy of oxygen delivery to meet demand. A randomised controlled trial of the use of peripheral FOE to guide the need for blood transfusions in preterm infants was carried out to test this hypothesis., Method: Infants less than 1500 g birth weight who were stable and less than 2 weeks old were randomised to receive transfusions guided by either a conventional protocol based on Hb (conventional group) or a protocol based on measurements of peripheral FOE made by near infrared spectroscopy (NIRS group). Measurements of Hb and FOE were made on all infants from randomisation until discharge. The primary outcome measures were number of transfusions received, rate of weight gain, and postmenstrual age at discharge., Results: Thirty seven infants were randomised to each group. Birth weight (median, range) (1200, 1004-1373 v 1136, 1009-1285 g) and Hb (median, range) at randomisation (160, 149-179 v 155, 145-181 g/l) did not differ between the two groups. The total number of transfusions given to the NIRS group was 56 and to the conventional group 84. The median number of transfusions per infant, the median volume of blood transfused to each group, and the total number of donors to which infants were exposed were similar in the two groups. Infants transfused according to the conventional protocol were more likely to be transfused earlier and at a higher Hb than those transfused in the NIRS group. Infants in the conventional group spent a significantly shorter period than those in the NIRS group with Hb < 100 g/l. Of the 56 transfusions given to the NIRS group, 33 (59%) were given because of clinical concerns rather than because of high FOE. There was no difference in the rate of weight gain, rate of linear growth, postmenstrual age at discharge, or the incidence of chronic lung disease or retinopathy of prematurity., Conclusions: FOE measurements failed to identify many infants felt by clinicians to require blood transfusion. This may have been because clinicians relied on conventional indicators of transfusion that are vague and non-specific, or a peripheral FOE of 0.47 alone may not be a sensitive enough predictor of the need for transfusion. This requires further study.