Low Perfusion and Missed Diagnosis of Hypoxemia by Pulse Oximetry in Darkly Pigmented Skin: A Prospective Study.

Background: Retrospective clinical trials of pulse oximeter accuracy report more frequent missed diagnoses of hypoxemia in hospitalized Black patients than White patients, differences that may contribute to racial disparities in health and health care. Retrospective studies have limitations including mistiming of blood samples and oximeter readings, inconsistent use of functional versus fractional saturation, and self-reported race used as a surrogate for skin color. Our objective was to prospectively measure the contributions of skin pigmentation, perfusion index (PI), sex, and age on pulse oximeter errors in a laboratory setting.

Morphological changes of intracranial pressure quantifies vasodilatory effect of verapamil to treat cerebral vasospasm.

Introduction: After aneurysmal subarachnoid hemorrhage (SAH), both proximal and distal cerebral vasospasm can contribute to the development of delayed cerebral ischemia. Intra-arterial (IA) vasodilators are a mainstay of treatment for distal arterial vasospasm, but no methods of assessing the efficacy of interventions in real time have been established.

Objective: To introduce a new method for continuous intraprocedural assessment of endovascular treatment for cerebral vasospasm.