In a patient being treated for a urinary tract infection caused by E. coli who presents with cyanosis, which abnormal hemoglobin is likely increased?

Get ready for the CAMLPR Hematology Test. Use our quizzes, flashcards, and detailed explanations to enhance your understanding. Prepare confidently for your exam!

Multiple Choice

In a patient being treated for a urinary tract infection caused by E. coli who presents with cyanosis, which abnormal hemoglobin is likely increased?

When a patient being treated for a urinary tract infection with a sulfonamide (such as sulfamethoxazole-trimethoprim) develops cyanosis, think about a dyshemoglobinemia caused by the drug. Sulfhemoglobinemia occurs when sulfur from the drug becomes incorporated into the heme group, creating sulfhemoglobin that cannot bind oxygen effectively. This reduces oxygen delivery to tissues and produces cyanosis that may not improve with supplemental oxygen. The condition is often associated with sulfonamide therapy and can persist for weeks after the drug is stopped because the sulfhemoglobin is not easily reversed. Carboxyhemoglobin would point to carbon monoxide exposure and typically gives a different color change and history. Methemoglobin is caused by oxidation of iron in hemoglobin and is also cyanotic, but it is more commonly linked to other oxidant drugs or exposures, not the sulfonamide used for a UTI. Hemoglobin A is normal adult hemoglobin and does not explain the cyanosis.

When a patient being treated for a urinary tract infection with a sulfonamide (such as sulfamethoxazole-trimethoprim) develops cyanosis, think about a dyshemoglobinemia caused by the drug. Sulfhemoglobinemia occurs when sulfur from the drug becomes incorporated into the heme group, creating sulfhemoglobin that cannot bind oxygen effectively. This reduces oxygen delivery to tissues and produces cyanosis that may not improve with supplemental oxygen. The condition is often associated with sulfonamide therapy and can persist for weeks after the drug is stopped because the sulfhemoglobin is not easily reversed.

Carboxyhemoglobin would point to carbon monoxide exposure and typically gives a different color change and history. Methemoglobin is caused by oxidation of iron in hemoglobin and is also cyanotic, but it is more commonly linked to other oxidant drugs or exposures, not the sulfonamide used for a UTI. Hemoglobin A is normal adult hemoglobin and does not explain the cyanosis.

More practice questions