1. Methemoglobinemia: An unusual cause of postoperative cyanosis
Carryn M Anderson, MD, Kenneth J Woodside, MD, Todd A Spencer, MD, Glenn C Hunter, MD 
Journal of Vascular Surgery 
Volume 39, Issue 3, Pages (March 2004)
DOI: /j.jvs

2. Fig 1
An arterial blood sample from our first patient at 12.7% MHb (left) and 31.0% MHb (right). Notice the dark brown hue of the sample with the higher MHb level.
Journal of Vascular Surgery  , DOI: ( /j.jvs )

3. Fig 2
Reduction of methemoglobin to hemoglobin. (From Wright OR, Lewander WJ, Woolf AD. Methemoglobinemia: etiology, pharmacology, and clinical management. Ann Emerg Med 1999;34: By permission).
Journal of Vascular Surgery  , DOI: ( /j.jvs )