Use of the bleeding time in the neonatal intensive care unit.

Impairments of primary hemostasis are frequently responsible for serious bleeding in sick infants in the neonatal intensive care unit (NICU). Therefore, a rational approach to these infants with hemorrhagic manifestations, in addition to an accurate medical history, a careful physical examination and routine screening coagulation tests, may include a bleeding time. The bleeding time is the traditional in vivo test for assessing primary hemostasis. It is a useful clinical tool to detect quantitative or qualitative platelet disorders or microvascular defectiveness. Its diagnostic value in neonates is controversial, mainly owing to limited experience in executing the test, which is performed uncommonly in the NICU. Using a template device expressly adapted for neonates (Surgicutt Newborn), a small incision 2.5 mm long and 0.5 mm deep provides a standardized, reproducible and sensitive bleeding time, with minimal scarring and pain. Various hereditary or acquired maternal and neonatal diseases, as well as some antepartum medications given to the mother or drugs commonly used to treat NICU patients, such as indomethacin, ibuprofen, penicillin compounds and theophylline, can impair primary hemostasis and consequently prolong the bleeding time in neonates. Furthermore, other factors distinctive to neonates, including gestational age, the increased von Willebrand factor concentration and function, high hematocrit, the large size of erythrocytes and platelet hyporeactivity in the first 10 d of life, affect platelet-vessel wall interaction and influence the interpretation of bleeding time results in newborn infants. Because the clinical evaluation of primary hemostasis consists of complex laboratory testing, largely reserved for specialized laboratories and currently not routinely performed in newborn infants, automated bleeding time devices specifically generated to make standardized and acceptably small incisions in newborn infants have become a surrogate.

CONCLUSIONS

With awareness of its value and limitations, the bleeding time can be included in the baseline evaluation of neonates in the NICU, for guiding diagnosis and treatment of primary hemostatic disorders.