A 40-year-old man is evaluated for perioral paresthesias and cramping of both hands. The patient has a history of alcoholic cirrhosis and was admitted 24 hours ago due to recurrent episodes of hematemesis. Evaluation revealed acute variceal bleeding for which the patient received endoscopic therapy. He also received 6 units of packed red blood cells and 4 units of fresh frozen plasma since admission. The patient reports feelings of anxiety and worsening tingling and numbness around the mouth for the past 2 hours. He has also had severe muscle spasms of the hands and legs. Temperature is 37.1 C (98.8 F), blood pressure is 116/68 mm Hg, and pulse is 92/min. Jugular venous pressure is normal. The lungs are clear to auscultation and heart sounds are normal. Abdominal examination reveals moderate ascites with no tenderness. He has generalized mild muscle weakness and periodic spontaneous twitching in the major muscle groups. Laboratory studies at the time of admission are as follows: Hemoglobin level after the transfusions is 8.9 g/dL. Further diagnostic testing is pending. Intravenous administration of which of the following is most likely to improve this patient's current symptoms?

Question

A 40-year-old man is evaluated for perioral paresthesias and cramping of both hands.  The patient has a history of alcoholic cirrhosis and was admitted 24 hours ago due to recurrent episodes of hematemesis.  Evaluation revealed acute variceal bleeding for which the patient received endoscopic therapy.  He also received 6 units of packed red blood cells and 4 units of fresh frozen plasma since admission.  The patient reports feelings of anxiety and worsening tingling and numbness around the mouth for the past 2 hours.  He has also had severe muscle spasms of the hands and legs.  Temperature is 37.1 C (98.8 F), blood pressure is 116/68 mm Hg, and pulse is 92/min.  Jugular venous pressure is normal.  The lungs are clear to auscultation and heart sounds are normal.  Abdominal examination reveals moderate ascites with no tenderness.  He has generalized mild muscle weakness and periodic spontaneous twitching in the major muscle groups.  Laboratory studies at the time of admission are as follows:  Hemoglobin level after the transfusions is 8.9 g/dL.  Further diagnostic testing is pending.  Intravenous administration of which of the following is most likely to improve this patient's current symptoms?

Quizplus · Accepted Answer

Explanation: 11ec2b69_c095_8f05_8f63_099389f0d28d_MD0005_00 This patient with liver disease who received several units of packed red blood cells over a short period developed perioral paresthesias and muscle cramping and twitching, raising suspicion for symptomatic hypocalcemia. Packed red blood cells are preserved and anticoagulated using sodium citrate and citric acid. These agents are rapidly cleared by the liver, kidney, and skeletal muscles and usually generate no adverse effects. However, patients who receive massive transfusions (usually >10 units) or those with certain underlying conditions (eg, hepatic disease, renal failure, hypothermia, shock) can fail to clear citrate quickly enough to prevent physiologic effects. As citrate binds ionized calcium, these patients are at risk for symptomatic hypocalcemia due to ionized (free) calcium deficiency. Diagnosis requires an ionized calcium level as serum calcium may be normal. Treatment with calcium gluconate or calcium chloride is usually curative, but several dosages may be required. (Choice B) Dextrose and thiamine are used as part of the treatment for Wernicke encephalopathy in patients with alcoholism or severe malnutrition. Wernicke encephalopathy is marked by oculomotor dysfunction, ataxia, and encephalopathy, not paresthesias and muscle cramping. (Choice C) Lorazepam can be used to treat seizures, which can occasionally present with muscle cramps and paresthesias. However, most patients will have additional neurologic findings such as episodic confusion, sleepiness, or clumsiness. As this patient with liver disease developed symptoms shortly after several blood transfusions, ionized calcium deficiency is more likely than seizures. (Choice D) High levels of citrate often result in metabolic alkalosis (from bicarbonate production with citrate metabolism), which can lead to hypokalemia due to the exchange of extracellular potassium for intracellular hydrogen. Although hypokalemia can cause muscle weakness and rhabdomyolysis, paresthesias and muscle spasms are less common. (Choice E) Sodium bicarbonate is typically used to treat severe metabolic acidosis as commonly seen in renal failure. Citrate causes a metabolic alkalosis; a sodium bicarbonate infusion would worsen the alkalosis. Educational objective: Packed red blood cells are preserved and anticoagulated using sodium citrate. Patients who receive massive transfusions or those with certain underlying conditions (eg, liver or renal failure, hypothermia, shock) can fail to adequately clear citrate. As citrate binds ionized calcium, these patients are at risk for symptomatic hypocalcemia due to ionized calcium deficiency. An ionized calcium level is required for diagnosis, as serum calcium is often normal.

A 40-Year-Old Man Is Evaluated for Perioral Paresthesias and Cramping