Background & Aims
Benzocaine ointment is a local anesthetic commonly used as a topical pain reliever for oral ulcers and stomatitis, It is contraindicated in children younger than 2 years of age. Benzocaine-induced methemoglobinemia is a rare complication associated with topical anesthesia and can be life–threatening.
Methods
In March 2020 a 2-year-old boy was admitted to our hospital for 2 days with lasting high temperature and 2-time watery mucous stool. The stool test detected adenoviruses. He had also an oral ulcer for which the pediatrician gave him benzocaine ointment as a pain reliever. On the 2nd day of treatment before discharging the child became cyanotic and his saturation decreased from 99 to 80% on pulse oximetry. He was transferred to PICU and was placed on 60% supplementation by face mask but his oxygen saturation continued to fall without other. The blood pressure was 136/70, heart rate was 180 beats/min. and respiratory rate was 54-56 act/min. Arterial blood gas showed pH 7.33, pO2 320mmHG, pCO2 40.7mmHG, and methemoglobin 32% of total hemoglobin. After the diagnosis of methemoglobinemia, the child was treated with methylene blue 1mg/kg IV and continuous O2 therapy. After 1 hour the cyanosis was revived and saturation was 99% without oxygen.
Results
After the diagnosis of methemoglobinemia, the child was treated with methylene blue 1mg/kg IV and continuous O2 therapy. After 1 hour the cyanosis was revived and saturation was 99% without oxygen.
Conclusions
Cyanosis with absence of cardiopulmonary symptoms should alert pediatricians to the possibility of an methemoglobinemia. The diagnosis is mainly clinical with cyanosis unresponse to oxygen therapy. The treatment of choice is low dose IV methylen blue which should be readily avaible in areas where topical anesthetics are frequently used.
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Presenting Author
Ariana Voskanyan
Poster Authors
Ariana Voskanyan
anesthesiologist
Muratsan Hospital Clinic
Lead Author
Topics
- Treatment/Management: Pharmacology: Adverse effects