Time (hours) Outside hospital At admission to author’s hospital(0 hours) 6hrs 9hrs 12hrs 18hrs 24hrs 32hrs Methemoglobin On co-oximetry 13.7% 16.3% 20.1% 19% 34.3% (plasma exchange) 3% 1.9% 0.4%

Table 1: Depicting the methemoglobin levels of the patient by cooximetry during hospital stay.