Inhaling One Hundred Percent Oxygen Eliminates the Systemic Arterial Hypoxemic Response of Broilers to Intravenous Microparticle Injections

ABSTRACT The pathogenesis of pulmonary hyperten-sion syndrome (PHS, ascites) includes the development of systemic arterial hypoxemia (reduction in the satura-tion of hemoglobin with O2, HbO2), which can be mim-icked in clinically healthy broilers by i.v. injections of microparticles (MP). In experiment 1, arterial blood sam-ples were collected from clinically healthy broilers before and after i.v. MP injections, and during a subsequent 100 % O2 inhalation period. The arterial samples were analyzed for HbO2, partial pressure of O2 and CO2, and pH using a blood gas analyzer. In experiment 2, broilers that initially averaged ≥75 % HbO2 were assigned to a “high O2 ” group, whereas those that initially averaged <75 % HbO2 were assigned to a “low O2 ” group. The HbO2 and heart rate (HR) were measured using a pulse oximeter before, during, and after broilers in both groups inhale