Case Reports in Emergency Medicine

Case Report

P-Chloroaniline Poisoning Causing Methemoglobinemia: A Case Report and Review of the Literature

Table 2

Arterial blood gas before and after administration of first dose of methylene blue 150 mg.


	Before methylene blue	After methylene blue

FiO₂ (fraction of inspired oxygen)	21%	100%
pH	7.401	7.378
pCO₂ [kPa]	5.59	5.01
pO₂ [kPa]	8.33	49.6
SaO₂ [%]	93.4	100
HCO₃ [mmol/L]	25.5	22.1
Oximetry results
Hb (hemoglobin [g/L])	130	108
FO₂Hb (fractional oxyglobin [%])	54.6	90.2
FCOHb (fractional carboxyhemoglobin [%])	0	0
FMetHb (fractional MetHb [%])	42.8	12.3
Lactate [mmol/L]	0.7	0.4

Arterial whole blood was analyzed on an ABL90 series blood gas analyzer, Radiometer Medical, Denmark. Arterial blood gas analyzers are based on electrochemistry and measure pH, pCO₂, and pO₂. Serum bicarbonate (HCO₃) and oxygen saturation (SaO₂) are calculated values (using the Henderson-Hasselbalch equation for serum bicarbonate and the standard oxygen-hemoglobin saturation curve for oxygen saturation).