Assessment of transcutaneous bilirubinometry in hospitalized adults

On the Sensitivity of Skin Spectral Responses to Variations in the Thickness of the Cutaneous Tissues

A wide range of devices are being routinely used in the noninvasive screening and monitoring of medical conditions through the analysis of skin spectral responses. The correct interpretation of these responses often depends on the availability of high-fidelity characterization datasets for the selected specimens. More specifically, the higher their fidelity, the more effective the quantification of changes observed in a given biophysical variable of interest. Skin thickness is among the most relevant of these parameters since it plays a pivotal role in the attenuation (scattering and absorption) of light traversing the cutaneous tissues. Transient and permanent physiological processes, such as tanning and ageing, can result in significant time-dependent thickness variations. These, in turn, can introduce biases in the comparison of skin spectral responses obtained at different time instances. In this paper, we investigate the impact of thickness variations on skin reflectance with respect to different regions of light spectrum. Our findings are expected to contribute to the mitigation of interpretation errors and, thus, to the enhancement of noninvasive screening and monitoring procedures based on skin spectral responses.

Novel UGT1A1 Gene Mutations in a Boy with Crigler-Najjar Syndrome Type II

In this article, we reported a patient with Crigler-Najjar syndrome type II with high-unconjugated bilirubin levels that decreased after phenobarbital treatment. The patient had two novel missense mutations in the UGT1A1 gene and a promoter variant in one allele. One mutation was c.1001T > C, that predicted leucine to proline substitution at position 334 (p.Leu334Pro). The other, c.1139A > G, predicted glutamic acid to glycine replacement at position 380 (p.Glu380Gly). In silico analysis indicated that both mutations are likely pathogenic.

On the Effective Differentiation and Monitoring of Variable Degrees of Hyperbilirubinemia Severity Through Noninvasive Screening Protocols

The presence of abnormal amounts of bilirubin in the blood stream and skin, usually referred to as hyperbilirubinemia, is associated with a wide range of pathologies that can pose considerable risks for human health. The early and effective screening of the severity degrees of this medical condition can play an important role on the selection of the appropriate treatment for the associated pathologies. This, in turn, can minimize the need for more aggressive and costly therapeutic interventions which can themselves pose considerable risks for morbidity and mortality. The current noninvasive protocols used to differentiate these severity degrees, however, are hindered by the relatively limited knowledge about the impact of different amounts of extravascular bilirubin on skin spectral responses and on the onset of jaundice, the resulting yellow-tinted skin appearance. In this paper, we address this open problem through controlled in silico experiments supported by measured data provided in the related literature. Our experimental findings bring biophysically-based insights to bear on the clarification of this biomedical entanglement, and unveil optical features that can potentially lead to more effective screening protocols for the noninvasive differentiation and monitoring of variable degrees of hyperbilirubinemia severity.

On the dysfunctional hemoglobins and cyanosis connection: practical implications for the clinical detection and differentiation of methemoglobinemia and sulfhemoglobinemia

Methemoglobinemia and sulfhemoglobinemia are potentially life-threatening blood-related disorders characterized by similar symptoms and markedly distinct treatment procedures. In this paper, we investigate the causal relationship between these conditions and the onset of cyanosis, which is typically associated with a purple or bluish skin coloration. More specifically, we perform controlled experiments to elicit cyanotic appearances resulting from different severity levels of these disorders and varying physiological conditions. We note that such experiments cannot be induced in living subjects without posing risks to their health. Accordingly, we have resorted to an in silico experimental approach supported by biophysical data reported in the literature. Besides bringing new insights about cyanotic chromatic variations elicited by methemoglobinemia and sulfhemoglobinemia, our investigation provides the basis for the proposition of a cost-effective protocol for the noninvasive detection and differentiation of these disorders. Our experimental results indicate that its sensitivity range is wider than what is provided by similar protocols employed in these tasks. Moreover, it has lower operational requirements than laboratory tests ordered to enable the diagnosis of these conditions. We believe that these aspects make the proposed protocol particularly suitable for deployment at the point of care of medical settings with limited access to laboratory resources.

Reassessment of different criteria for diagnosing post-hepatectomy liver failure: a single-center study of 1683 hepatectomy

Assessing the incidence and severity of post-hepatectomy liver failure (PHLF) can be based on different criteria, and we wished to compare the diagnostic efficiency and specificity of different PHLF criteria. Data from patients (n=1683) who received hepatectomies in the liver surgery department of Peking Union Medical College Hospital from April 2008 to August 2014 were retrospectively analyzed. Possible PHLF patients were screened according to the criteria of the International Study Group of Liver Surgery (ISGLS). Subsequently, other PHLF evaluation methods, including Child-Pugh score, “50-50” criteria, Model for End-Stage Liver Disease (MELD) score, and Clavien-Dindo classification were used to assess the suspected PHLF patients, and statistical analysis was performed for correlation of these methods with clinical prognoses. Using ISGLS grading, 40 cases (2.38%) were suspected to have PHLF, among whom 5 (0.30%) patients died. Of the 40 cases there were 9 patients of ISGLS grade A, 21 of grade B, and 10 of grade C. Among the entire group, Child-Pugh scoring showed 3 patients in grade A, 35 in grade B, and 2 in grade C, while only 5 patients met the “50-50” criteria. Interestingly, MELD scores ≥11 points were found only in 3 cases. Twenty-eight patients were classified as Clavien-Dindo grade I, 8 as grade II, 3 as grade III, and 1 as grade IV. Prothrombin time on postoperative day 5 (PT5), ISGLS, and Clavien-Dindo were found to have significant correlation with the prognosis of PHLF (r>0.5, p <0.05), thus can be used as prognosis predictors for PHLF patients.

Hyperbilirubinemia and Transcutaneous Bilirubinometry

Background: Neonatal jaundice or hyperbilirubinemia is a common occurrence in newborns. Although most cases of neonatal jaundice have a benign course, severe hyperbilirubinemia can lead to kernicterus, which is preventable if the hyperbilirubinemia is identified early and treated appropriately.

Content: This review discusses neonatal jaundice and the use of transcutaneous bilirubin (TcB) measurements for identification of neonates at risk of severe hyperbilirubinemia. Such a practice requires appropriate serial testing and result interpretation according to risk level from a nomogram that provides bilirubin concentrations specific for the age of the neonate in hours. In this context, we have evaluated the potential impact on clinical outcome and limitations of TcB methods in current use.

Summary: TcB measurement is a viable option in screening neonates to determine if they are at risk for clinically significant hyperbilirubinemia. Total serum bilirubin should be measured by a clinical laboratory if a newborn is shown to be at higher risk for clinically significant hyperbilirubinemia. In addition, external quality assessment to identify biases and operator training issues should be part of any TcB monitoring program.