Methemoglobinemia: A Bariatric Case Study

Abstract

With the incidence of obesity on the rise in the United States, as well as worldwide, we are seeing a steady increase in the number of surgical weight loss interventions to treat this disease. Roux-en-Y gastric bypass, a restrictive and malabsorptive procedure, remains a popular, effective, and safe method of treating obesity. Despite refined techniques, it is not without risks and complications. One such complication is stomal stenosis, which usually occurs at the proximal anastomosis, and can be diagnosed in patients as early as 4 weeks postoperatively. Prompt diagnosis of this complication can be identified and treated by upper endoscopy and balloon dilation. Topical spray anesthesia is commonly used when performing endoscopic procedures. Surgeons, anesthesiologist, and gastroenterologists have been using this technique for a number of years to reduce the need for higher doses of conscious-sedating medications. Unfortunately, the use of topical spray products can result in the rare life-threatening reaction methemoglobinemia. Despite the widespread and accepted use of these agents, few endoscopists have experience or knowledge regarding this serious complication. Because surgeons are performing a substantial number of endoscopies in this country, it is imperative that unfamiliarity with this potential complication be corrected. Unfamiliarity will inevitably result in a delay in diagnosis and appropriate treatment. A diagnosis of methemoglobinemia should be entertained when, despite oxygen therapy, cyanosis persists without identifiable pulmonary or cardiac pathology. The following is a case presentation revealing an example of the associated risk of methemoglobinemia associated with the use of topical spray anesthetics in a bariatric patient. This patient was undergoing upper endoscopy to identify and treat an anastomotic stricture.