WBR0829
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| Author | PageAuthor::Vendhan Ramanujam |
|---|---|
| Exam Type | ExamType::USMLE Step 3 |
| Main Category | MainCategory::Inpatient Facilities, MainCategory::Emergency Room |
| 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 the following laboratory tests
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| Answer A | AnswerA::Continuous infusion of intravenous regular insulin and isotonic 0.9% normal saline |
| Answer A Explanation | AnswerAExp::'''Incorrect'''-Since the patient’s serum potassium has gone below 5.3 mEq/L, potassium should be added to the continuous infusion of intravenous regular insulin and isotonic 0.9% normal saline. |
| Answer B | AnswerB::Continuous infusion of intravenous regular insulin and hypertonic D5 normal saline |
| Answer B Explanation | AnswerBExp::'''Incorrect'''-Hypertonic D5 normal saline should replace the isotonic normal saline only when blood glucose falls below 200 mg/dL. |
| Answer C | AnswerC::Continuous infusion of intravenous regular insulin, hypertonic D5 normal saline and potassium |
| Answer C Explanation | AnswerCExp::'''Incorrect'''-Hypertonic D5 normal saline should replace the isotonic normal saline only when blood glucose falls below 200 mg/dL. |
| Answer D | AnswerD::Continuous infusion of intravenous regular insulin, isotonic 0.9% normal saline and potassium |
| Answer D Explanation | [[AnswerDExp::Correct-The first line of management of diabetic ketoacidosis (DKA) is starting the patient on a continuous infusion of intravenous regular insulin and isotonic 0.9% normal saline. Potassium is supplemented when serum potassium falls below 5.3 mEq/L.]] |
| Answer E | AnswerE::Continuous infusion of intravenous regular insulin, isotonic 0.9% normal saline, potassium and sodium bicarbonate |
| Answer E Explanation | [[AnswerEExp::Incorrect-Sodium bicarbonate can be administered only when acidosis (<7) is accompanied by a severe (<5 mEq/L) fall in serum bicarbonate level and life threatening hyperkalemia. Otherwise, sodium bicarbonate infusion can lead to neurological deterioration, slowing of the rate of recovery of ketosis and post treatment alkalosis.]] |
| Right Answer | RightAnswer::D |
| Explanation | [[Explanation::The first line of management of diabetic ketoacidosis (DKA) after confirming with a simple rapid finger glucose test and relevant serum biochemistry, urine analysis and arterial blood gas analysis tests will be starting the patient on a continuous infusion of intravenous regular insulin and isotonic 0.9% normal saline. The only indication for delaying insulin therapy will be serum potassium below 3.3 meq/L since insulin will worsen hypokalemia by driving potassium into the cell. Isotonic saline will rapidly correct the extracellular volume depletion, lower the plasma osmolality in the hypoosmotic patient, and reduce the serum glucose concentration both by dilution and by increasing urinary losses as renal perfusion is increased. Most patients are switched at some point to one-half isotonic saline to replace the free water loss induced by the glucose osmotic diuresis. When this should occur is uncertain, because of concern about the possible development of cerebral edema if the plasma osmolality is reduced too rapidly. Intravenous potassium chloride is supplemented when serum potassium falls below 5.3 mEq/L and intravenous sodium bicarbonate can be supplemented when acidosis (<7) is accompanied by a severe (<5 mEq/L) fall in serum bicarbonate level and life threatening hyperkalemia. Blood glucose should be monitored every one hour and other parameters every 4 to 6 hours. This regimen will be continued until the patient’s anion gap corrects to normal (3-11 mEq/L).
Educational Objective:
The first line of management of diabetic ketoacidosis (DKA) after confirming with a simple rapid finger glucose test and relevant serum biochemistry, urine analysis and arterial blood gas analysis tests will be starting the patient on a continuous infusion of intravenous regular insulin and isotonic 0.9% normal saline. Potassium can be supplemented when serum potassium falls below 5.3 mEq/L and sodium bicarbonate can be supplemented when acidosis (<7) is accompanied by a severe (<5 mEq/L) fall in serum bicarbonate level and life threatening hyperkalemia. |
| Approved | Approved::Yes |
| Keyword | WBRKeyword::Diabetic ketoacidosis |
| Linked Question | Linked:: |
| Order in Linked Questions | LinkedOrder:: |