Assessment of Transcutaneous Bilirubinometry in Hospitalized Adults

Background: Transcutaneous techniques to measure serum bilirubin have been validated in neonates but not in adult patients. We evaluated transcutaneous bilirubinometry (TcB) in adults at risk for or diagnosed with hepatic dysfunction to determine if this technology has clinical use in quantifying the presence and magnitude of hyperbilirubinemia. Design: Unblinded, consecutive hospitalized adult patients (n = 80) from the general surgery, trauma surgery, and liver resection/transplantation services of a tertiary care, university-affiliated medical center, who were having serum bilirubin measurements performed, underwent transcutaneous bilirubin measurement from the forehead, sternum, forearm, and deltoid. Transcutaneous bilirubin measurements were repeated each time serum bilirubin measurements were performed. Results: Transcutaneous bilirubin measurements from the forehead correlated with serum bilirubin better (r, 0.963) than measurements from the forearm (r, 0.792), deltoid (r, 0.922), or sternum (r, 0.928). Forehead TcB detected hepatic dysfunction (serum bilirubin ≥ 2 mg/dL) by receiver operator curves (area under the curve = 0.971) and sternum (area under the curve = 0.970) and better than deltoid and forearm measurements (area under the curve = 0.935 and 0.893, respectively). A Bland-Altman plot demonstrated that forehead measurements became less accurate as the magnitude of hyperbilirubinemia increased. Conclusions: Forehead TcB correlated best with serum bilirubin levels but became less accurate at higher values. Refinements in the technology will be required before this technique, although promising, can be considered for routine clinical application in adults being evaluated for hyperbilirubinemia.