Abstract

FURZAN, Jaime A; EXPOSITO, Mercedes  and  LUCHON, Consuelo. Correlación entre bilirrubina serica y bilirrubinometría transcutánea en neonatos estratificados por edad gestacional. Arch Venez Puer Ped [online]. 2007, vol.70, n.2, pp.39-46. ISSN 0004-0649.

Background: Newborn jaundice with its potential for producing brain damage remains a continuing problem for pediatricians. Therapeutic decisions based on serial measurements of serum bilirubin (TSB) are time-consuming and associated with stress for the child, parents and practitioners. Transcutaneous bilirubinometry (TCB) may be an alternative method if its reliability is proven for a particular institution and population. Objective: to establish the degree of correlation between TSB and TCB in newborn infants classified by gestational age. Methods: cross-sectional study. 100 jaundiced infants, stratified into two groups of 50 preterm and 50 full-term newborns, were analyzed by simultaneous samples of TSB and TCB. Statistical analysis included estimates of differences between the two measurements, coefficients of variation of means, correlation coefficients, sensitivity and positive predictive value of TCB, and accuracy of TCB to predict significant hyperbilirubinemia Results: the coefficient of variation of means was similar for both methods (TSB: 3.09%; TCB: 3.24%). Measurements of TSB and TCB were different in 95 infants and equivalent in 5. TCB underestimated TSB in 59 measurements and overestimated it in 36 of them, with a mean difference of 1.39 mg/dl (SD 0.58 mg/dl). Sensitivity of TCB to identify a TSB >12 mg/dl was 87%, with a positive predictive value of 94%. The global correlation coefficient was 0.88 (term infants: 0.92; preterm infants: 0.84). 82% of the infants were correctly classified by the TCB within the percentiles of risk for significant hyperbilirubinemia. Conclusions: precision of measurements of TSB and TCB is similar in our institution. Despite a good correlation between the two methods, regardless the gestational age, TCB tends to underestimate TSB when bilirubin values go beyond 12 mg/dl. The TCB technique can accurately predict the risk of extreme hyperbilirubinemia, so it can be cautiously used prior to discharge to reduce this risk and to avoid unnecessary interventions.

Keywords : newborn; jaundice; transcutaneous bilirubinometry.