WBR0911
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| Author | PageAuthor::Vendhan Ramanujam |
|---|---|
| Exam Type | ExamType::USMLE Step 3 |
| Main Category | MainCategory::Inpatient Facilities |
| Sub Category | SubCategory::Endocrine, SubCategory::Electrolytes |
| Prompt | [[Prompt::A 28 year old African-American male presented to the emergency department with complaints of lethargy and vomiting for the past one day. He is a known type 1 diabetes mellitus patient. He had a gastrointestinal disturbance before two days following which he restricted his food intake and skipped his insulin doses. He also played soccer with his friends last evening. Physical examination revealed a confused, dehydrated, tachypneic male with vital signs like heart rate of 120 beats/min, blood pressure of 98/58 mmHg, respiratory rate of 35/minute and oral temperature of 37.2 C. A rapid finger glucose test revealed plasma glucose of 638 mg/dL, thus confirming diabetic ketoacidosis. He was started on 0.9% normal saline while waiting for his lab results, which revealed a high anion gap metabolic acidosis with serum potassium below 5.3 mEq/L. He was admitted in the intensive care unit and started on a continuous infusion of intravenous regular insulin, isotonic 0.9% normal saline and potassium. Repeat blood tests after four hours revealed the following
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| Answer A | AnswerA::Continue the continuous infusion of intravenous regular insulin, isotonic 0.9% normal saline and potassium |
| Answer A Explanation | [[AnswerAExp::Incorrect-Since the blood glucose level had gone below 200 mg/dL and serum potassium above 5.3 mEq/L, continuous infusion of intravenous regular insulin, isotonic 0.9% normal saline or one-half isotonic 0.9% normal saline and potassium should not be continued.]] |
| Answer B | AnswerB::Continuous infusion of intravenous regular insulin, one-half isotonic 0.9% normal saline and potassium |
| Answer B Explanation | [[AnswerBExp::Incorrect-Since the blood glucose level had gone below 200 mg/dL and serum potassium above 5.3 mEq/L, continuous infusion of intravenous regular insulin, isotonic 0.9% normal saline or one-half isotonic 0.9% normal saline and potassium should not be continued.]] |
| Answer C | AnswerC::Continuous infusion of intravenous regular insulin, hypertonic D5 normal saline and potassium |
| Answer C Explanation | [[AnswerCExp::Incorrect-This patient should be stopped from further receiving the continuous infusion of the full dose of regular insulin and isotonic saline since it will promote the development of cerebral edema and potassium infusion is not required since serum potassium has gone above 5.3 mEq/L.]] |
| Answer D | AnswerD::Continuous intravenous infusion of half the previous dosage of regular insulin, hypertonic D5 normal saline and potassium |
| Answer D Explanation | [[AnswerDExp::Incorrect-This patient should be stopped from further receiving the continuous infusion of the full dose of regular insulin and isotonic saline since it will promote the development of cerebral edema and potassium infusion is not required since serum potassium has gone above 5.3 mEq/L.]] |
| Answer E | AnswerE::Continuous intravenous infusion of half the previous dosage of regular insulin, and hypertonic D5 normal saline |
| Answer E Explanation | [[AnswerEExp::Correct-Since the blood glucose has fallen below 200 mg/dL, diabetic ketoacidosis patients on treatment are switched over to half the dosage of regular insulin that they were receiving and the isotonic saline is replaced by hypertonic D5 normal saline to prevent the complication of development of cerebral edema.]] |
| Right Answer | RightAnswer::E |
| Explanation | [[Explanation::Following the initial line of management of this diabetic ketoacidosis (DKA) patient with continuous infusion of intravenous regular insulin, isotonic 0.9% normal saline and potassium, repeat blood tests reveled a blood glucose level below 200 mg/dL, anion gap >11mEq/L and serum potassium >5.3 mEq/L. When blood glucose level falls below 200 mg/dL, to prevent the development of cerebral edema, insulin is reduced to half the its previous dose and isotonic saline is replaced by hypertonic D5 normal saline. Further potassium supplementation will not be required since the serum potassium level had gone above 5.3 mEq/L. The regimen will be continued until the patient’s anion gap corrects to normal (3-11 mEq/L).
Educational Objective:
When the blood glucose falls below 200 mg/dL, diabetic ketoacidosis patients on treatment should be switched over to half the dosage of regular insulin that they were receiving and the isotonic saline be replaced by hypertonic D5 normal saline to prevent the complication of development of cerebral edema. |
| Approved | Approved::Yes |
| Keyword | WBRKeyword::Diabetic ketoacidosis |
| Linked Question | Linked:: |
| Order in Linked Questions | LinkedOrder:: |