WBR0227

Author	[[PageAuthor::Mugilan Poongkunran M.B.B.S [1]]]
Exam Type	ExamType::USMLE Step 3
Main Category	MainCategory::Emergency Room
Sub Category	SubCategory::Electrolytes
Prompt	[[Prompt::A 40 yr old male is brought by his daughter to the ER with complaints of anorexia, nausea, vomiting, muscle cramps and weakness for the past two days. His daughter says he attended a party with his friend’s couple of days back. He is a known diabetic on regular oral hypoglycaemic drugs. On Physical examination his temperature is 36.7 C, blood pressure is 130/70 mmHg, pulse is 102/min and respiartions are 16/min. His oxygen saturation is 97% on room air. His fingerpick test show glucose of 110 mg/dl. On neurological examination, the patient is consious and cooperative. He knows his name and oriented to time and place. He can move all his extremities. Touch sensation are intact but deep tendon reflexes are sluggish. He is adequately hydrated and his EKG reveals prolonged PR and QT intervals. Serum chemistry shows Na:135 mEq/L, K: 3 mEq/L, Cl:104mEq/L, Bi: 24 mEq/L, BUN: 30 mg/dl, glucose:72 mg/dl, Mg:1mg/dl and Ca: 8mg/dl. What is the most appropriate way to manage this patient?]]
Answer A	AnswerA::Start him on I.V calcium gluconate
Answer A Explanation	[[AnswerAExp::Incorrect : I.V calcium gluconate is given when ECG shows T-wave fl attening, U waves (an additional wave after the T wave), and ST-segment depression, leading to AV block and subsequent cardiac arrest. Replace magnesium, as this deficiency complicates calcium repletion.]]
Answer B	AnswerB::Start IV Potassium supplementation
Answer B Explanation	[[AnswerBExp::Incorrect : IV potassium repletion is done when the patients presents with symptoms of hypokalemia like fatigue, muscle weakness or cramps, ileus. Do not exceed 20 mEq/L/hr. Replace magnesium, as this deficiency complicates potassium repletion.]]
Answer C	AnswerC::Administer oral calcium supplements
Answer C Explanation	AnswerCExp::'''Incorrect''' : Oral supplementation are only preferable for chronic asymptomatic condtions.
Answer D	[[AnswerD::Start him on both I.V calcium gluconate and I.V potassium]]
Answer D Explanation	AnswerDExp::'''Incorrect''' : Hypokalemia and hypocalcemia is done only after magnesium correction.
Answer E	AnswerE::Start him on IV Magnesium
Answer E Explanation	AnswerEExp::'''Correct''' : Hypokalemia and hypocalcemia will not correct without magnesium correction.
Right Answer	RightAnswer::E
Explanation	[[Explanation::Serum magnesium < 1.5 mEq/L is hypomagnesemia. The etiologies are reduced 1. Reduced intake: Malnutrition, malabsorption, short bowel syndrome, TPN 2. Increased loss: Diuretics, diarrhea, vomiting, hypercalcemia, drugs (e.g., aminoglycosides, amphotericin), alcoholism, kidney losses (e.g., recovering ATN, postobstructive dieresis) 3. DKA, pancreatitis, extracellular fluid volume expansion are other causes. Symptoms are generally related to concurrent hypocalcemia and hypokalemia; they include anorexia, nausea, vomiting, muscle cramps, and weakness. In severe cases, symptoms may also include hyperactive reflexes, tetany, paresthesias, irritability, confusion, lethargy, seizures, and arrhythmias. Labs may show concurrent hypocalcemia and hypokalemia. ECG may reveal prolonged PR and QT intervals. IV and oral supplements. Educational Objective: References: ]]
Approved	Approved::Yes
Keyword
Linked Question	Linked::
Order in Linked Questions	LinkedOrder::