A 28-year-old woman is hospitalized following a motor vehicle accident. She was returning home following a wine-tasting event when she veered off the road and rolled her car. Initial evaluation in the emergency department found severe hypotension, a hip fracture, multiple rib fractures, and evidence of blunt abdominal trauma. The patient underwent emergent laparotomy, which revealed a liver laceration and extensive hemoperitoneum. Her condition was stabilized with surgical intervention, fluid resuscitation, and blood transfusions. In the early postoperative period soon after extubation, the patient developed numbness in the fingertips and around her lips. She also developed forceful flexion of the wrist with abduction of the thumb while her nurse was measuring her blood pressure. Temperature is 37.4 C (99.3 F), blood pressure is 120/68 mm Hg, pulse is 80/min, and respirations are 12/min. Neurologic examination shows hyperactive reflexes diffusely with 5/5 muscle strength in all extremities. Which of the following is the most likely diagnosis?

Question

A 28-year-old woman is hospitalized following a motor vehicle accident.  She was returning home following a wine-tasting event when she veered off the road and rolled her car.  Initial evaluation in the emergency department found severe hypotension, a hip fracture, multiple rib fractures, and evidence of blunt abdominal trauma.  The patient underwent emergent laparotomy, which revealed a liver laceration and extensive hemoperitoneum.  Her condition was stabilized with surgical intervention, fluid resuscitation, and blood transfusions.  In the early postoperative period soon after extubation, the patient developed numbness in the fingertips and around her lips.  She also developed forceful flexion of the wrist with abduction of the thumb while her nurse was measuring her blood pressure.  Temperature is 37.4 C (99.3 F), blood pressure is 120/68 mm Hg, pulse is 80/min, and respirations are 12/min.  Neurologic examination shows hyperactive reflexes diffusely with 5/5 muscle strength in all extremities.  Which of the following is the most likely diagnosis?

Quizplus · Accepted Answer

11ec25c8_d8cd_6960_bc81_772e3df07eb1_MD0003_00 This patient has paresthesias, carpal spasm (Trousseau sign), and hyperreflexia. In the setting of high-volume transfusion, these neurologic features are most likely due to hypocalcemia. Other potential features of severe hypocalcemia include tetany, laryngospasm, seizures, encephalopathy, and heart failure. Patients with chronic hypocalcemia may have only mild symptoms, but patients with acute hypocalcemia will have more severe manifestations at the same calcium concentration. carpal spasm (Trousseau sign) Citrate in transfused blood binds ionized calcium, which is the biologically active fraction (total calcium levels will not be significantly affected). Hypocalcemia is uncommon following blood transfusion in patients with normal liver function as citrate is rapidly metabolized by the liver; however, this patient likely has hepatic dysfunction due to the liver laceration as well as ischemic liver injury due to hypotension. Other infused substances that can chelate calcium in the blood include lactate, foscarnet, and sodium ethylenediaminetetraacetic acid (EDTA). (Choice A) Alcohol withdrawal is most pronounced 12-48 hours following the last drink. Clinical features may include hyperreflexia, tremor, diaphoresis, and gastrointestinal upset, but carpal spasm and paresthesias are more consistent with hypocalcemia. (Choice B) Hyperventilation due to anxiety can cause acute respiratory alkalosis, increasing the binding of calcium to albumin and reducing ionized calcium concentrations. However, this patient's respiratory rate is only 12/min. (Choice C) Fat embolism can occur following pelvic or long bone fractures. Manifestations of fat embolism include respiratory insufficiency, hypoxemia, altered mental state, and petechial rash. (Choice D) Hypomagnesemia (not hypermagnesemia) can present similarly to hypocalcemia. Severe hypermagnesemia causes hyporeflexia, paralysis, apnea, and cardiac arrest. Rarely, very severe hypermagnesemia can cause hypocalcemia by inhibiting parathyroid hormone release, but this would typically be seen with infusions of magnesium, such as in the treatment of severe preeclampsia and eclampsia. Educational objective: High-volume blood transfusion can cause symptomatic hypocalcemia due to chelation of ionized calcium by citrate in transfused blood. Patients with impaired hepatic function are at increased risk due to decreased clearance of citrate by the liver. References: Effects of liver function on ionized hypocalcaemia following rapid blood transfusion (http://www.ncbi.nlm.nih.gov/pubmed/22613418)

A 28-Year-Old Woman Is Hospitalized Following a Motor Vehicle Accident