Examkin

Question

Difficulty: Very hardPhysiological Adaptation

A client in the trauma intensive care unit is receiving a massive transfusion protocol for severe hemorrhagic shock following a pelvic crush injury. After the rapid administration of 8 units of packed red blood cells and 6 units of fresh frozen plasma, the client's continuous electrocardiogram reveals a newly prolonged QT interval of 0.54 seconds. The nurse observes circumoral tingling and muscle fasciculations. Current vital signs include a heart rate of 112 beats per minute, blood pressure of 86/48 mm Hg, and a central venous pressure (CVP) of 9 mm Hg. Which of the following is the priority nursing action?

  1. A
    Stop the current blood product infusions and aspirate the intravenous line
  2. B
    Increase the infusion rate of 0.9% sodium chloride to treat unresolved hypovolemia
  3. Administer prescribed intravenous calcium gluconateAnswer
  4. D
    Administer prescribed intravenous sodium bicarbonate to treat anticipated lactic acidosis

Answer

The correct action is to administer prescribed intravenous calcium gluconate.
The client is exhibiting clear signs of citrate toxicity, a known and dangerous complication of massive blood transfusions. Citrate, used as an anticoagulant in stored blood products, rapidly binds with the client's ionized calcium, precipitating severe hypocalcemia. This lack of ionized calcium manifests as neuromuscular irritability (circumoral tingling, fasciculations), a prolonged QT interval on the ECG, and decreased myocardial contractility (causing hypotension despite an adequate CVP of 9 mm Hg). The priority action is to immediately replace the ionized calcium by administering intravenous calcium gluconate or calcium chloride.

Step-by-Step Solution

1
Analyze the client's clinical presentation in the context of recent interventions.
The client received massive blood transfusions and is now exhibiting a prolonged QT interval, neuromuscular irritability, and hypotension.
To identify the underlying pathophysiological cause of the sudden deterioration.
2
Correlate the symptoms with potential complications of massive transfusion.
The symptoms are classic indicators of severe hypocalcemia caused by citrate toxicity.
Blood products contain citrate as an anticoagulant, which rapidly binds to the client's circulating ionized calcium.
3
Evaluate the hemodynamic parameters to determine the cause of hypotension.
The CVP is 9 mm Hg, indicating adequate right-sided filling pressures. The hypotension is therefore related to the negative inotropic effect of hypocalcemia, not hypovolemia.
To rule out unresolved hemorrhagic shock and prevent fluid overload.
4
Determine the most appropriate and immediate nursing intervention.
Administering intravenous calcium gluconate will directly correct the life-threatening ionized hypocalcemia.
Replacing ionized calcium restores myocardial contractility, resolves neuromuscular irritability, and shortens the dangerously prolonged QT interval.

Key Concept

Citrate Toxicity and Hypocalcemia in Massive Transfusions
Rate this question

Topics

Physiological Adaptation

More questions from this topic