Masimo Corporation announced that a novel study on Rainbow SET Pulse CO-Oximetry is presented at the Society for Critical Care Medicine. The study suggests that providers should consider routine screening with Masimo Rainbow SET Pulse CO-Oximetry for the immediate and noninvasive detection of potentially life-threatening acquired methemoglobinemia in patients receiving Dapsone therapy. Results showed that "Dapsone therapy is associated with a clinically significant elevation of methemoglobin levels" in 1 out of 7 HIV+ patients. In the study, Hollis R. O'Neal, M.D., and colleagues at the Vanderbilt University School of Medicine in Nashville, found that 32% of HIV positive patients receiving chronic Dapsone therapy, a commonly used antimicrobial agent for the treatment of prophylaxis of pneumocystis jirovecii pneumonia (PCP), had elevated methemoglobin blood levels (>2%) and 15% had dangerously high methemoglobin blood levels (>3%) when compared to a control group of HIV positive patients not receiving Dapsone. Dapsone has been shown to cause potentially deadly levels of methemoglobin, which is a damaged form of hemoglobin that cannot bind to oxygen to accumulate in the blood. Elevated methemoglobin concentration reduces oxygen delivery to vital organs and tissues, which can lead to brain and organ damage, or even death. The researchers concluded: "As noninvasive Pulse CO-Oximetry is now available, providers should consider the routine screening of persons receiving Dapsone for methemoglobinemia."