International anatolıan congress on multıdıscıplınary scıentıfıc researc, Mardin, Mardin, Turkey, 12 - 13 August 2022, pp.8-9
In order for oxygen molecules to be transported to the tissues by hemoglobin under normal conditions, the iron molecule in its structure must have +2 (Fe+2) valence. In methemoglobinemia, due to various oxidative stresses, iron becomes +3 valent (Fe+3) and methemoglobin, which cannot carry oxygen to the tissues, emerges.
Methemoglobinemia can be congenital or acquired. Acquired methemoglobinemia is most commonly seen after local anesthetic drugs. Under physiological conditions, the methemoglobin value is less than 2-3% of the total hemoglobin. If it exceeds 15%, agitation, cyanosis and hypoxia develop and become symptomatic.
Treatment of methemoglobinemia is removal of the triggering agent and the use of methylene blue as an antidote. In cases where methylene blue treatment is ineffective or cannot be used, ascorbic acid, exchange transfusion, and hyperbaric oxygen therapy can be used as additional options.
Cholecystostomy was indicated in two patients, aged 47 and 60 years, who were hospitalized in our clinic for acute calculous cholecystitis. Cholecystostomy was performed in both patients under local anesthesia with prilocaine. Dyspnea, agitation and hypotension developed in the clinic approximately 30-60 minutes after the procedure. On physical examination, oxygen saturation was 85% and blood pressure was 90/60 despite oxygen support. Breath sounds were normal on auscultation. As the patients did not improve in their clinics despite oxygen support and peripheral cyanosis findings persisted, arterial gases were taken and methemoglobin levels were found to be high between 35-40%. Clinical improvement was achieved in one of the patients with methylene blue infusion therapy and oxygen support. In the other patient, ascorbic acid and oxygen support was provided because methylene blue could not be found. In the blood gas follow-ups of the patients, the methemoglobin value returned to normal and clinical improvement was achieved.
As a result, dyspnea can be detected as a result of inability to perform deep inspiration due to pain due to both acute cholecystitis clinic and invasive procedures. However, the lack of clinical improvement and cyanosis in the distal extremity, especially after the injection of prilocaine, which is a frequently used local anesthetic for cholecystostomy, should suggest methemoglobinemia.
Key words: Cholecystostomy, prilocaine, methemoglobinemia