WBR0201
| Author | [[PageAuthor::Ayokunle Olubaniyi, M.B,B.S [1] (Edited by Alison Leibowitz)]] |
|---|---|
| Exam Type | ExamType::USMLE Step 2 CK |
| Main Category | MainCategory::Internal medicine |
| Sub Category | SubCategory::Genitourinary, SubCategory::Genitourinary, SubCategory::Preventive Medicine |
| Prompt | [[Prompt::A 72-year-old man with a history of chronic obstructive pulmonary disease (COPD), stroke, elevated cholesterol, and dementia is brought to the ER by his wife for fever and shortness of breath during past three days. He underwent an oral surgical procedure 6 weeks ago. Upon examination, the temperature is 36.8°C, the blood pressure is 140/60 mm Hg, and the respiratory rate is 22 breaths per minute. A soft diastolic murmur is heard and gentamicin therapy is initiated. Which of the following tests should have been administered in order to monitor the medication's adverse reactions?]] |
| Answer A | AnswerA::Check creatine kinase level |
| Answer A Explanation | [[AnswerAExp::Determining Creatine Kinase level is useful in acute coronary syndrome]] |
| Answer B | AnswerB::Hearing test with a tuning fork |
| Answer B Explanation | AnswerBExp::A prior hearing test with a tuning fork has no preventive advantage in this case. |
| Answer C | AnswerC::Check creatinine clearance |
| Answer C Explanation | [[AnswerCExp::Creatinine clearance is a measure of the glomerular filtration rate. The glomerular filtration rate is a measure of the renal status.]] |
| Answer D | AnswerD::Chest X-ray |
| Answer D Explanation | AnswerDExp::A chest X-ray is not necessary because the patient has no cardiac or pulmonary pathology. |
| Answer E | AnswerE::Cranium X-ray |
| Answer E Explanation | [[AnswerEExp::A cranium X-ray is required in pathologies involving the cranium such as skullbase fractures.]] |
| Right Answer | RightAnswer::C |
| Explanation | [[Explanation::Gentamicin is both nephrotoxic and ototoxic. Gentamicin is a vestibulotoxin capable of causing permanent loss of equilibrioception and sensorineural hearing loss. This is caused by damage to the vestibular apparatus of the inner ear usually if taken at high doses or for prolonged periods of time. Elderly people are at a very high risk because they have a lower glomerular filtration rate (GFR), thus, it is mandatory to check their creatinine clearance before administering the medication.
Educational Objective: The glomerular filtration rate is reduced in the young and in the elderly, which reduces the clearance of medications in them. In the elderly, the creatinine clearance must be calculated before the administration of nephrotoxic drugs such as gentamicin. |
| Approved | Approved::Yes |
| Keyword | WBRKeyword::GFR, WBRKeyword::gentamicin toxicity, WBRKeyword::nephrotoxicity |
| Linked Question | Linked:: |
| Order in Linked Questions | LinkedOrder:: |