At what point after a burn injury should the nurse be most alert for the complication of hypokalemia?
A. Immediately following the injury
B. During the fluid shift
C. During fluid remobilization
D. During the late acute phase
The correct answer and explanation is:
Correct Answer: C. During fluid remobilization
Explanation:
Hypokalemia, or low potassium levels in the blood, is a potential complication following a burn injury. Burn pathophysiology typically occurs in phases. These phases influence the timing and type of electrolyte imbalances a patient might experience.
Immediately after the burn injury, in the emergent or resuscitation phase, the body experiences massive fluid shifts due to increased capillary permeability. This allows fluid and electrolytes, including potassium, to move from the intravascular space into the interstitial space. During this period, potassium is often elevated (hyperkalemia), primarily due to the destruction of cells that release potassium into the bloodstream. Therefore, hypokalemia is not usually seen immediately after the burn or during the early fluid shift phase.
During the fluid remobilization phase, which begins approximately 48 to 72 hours after the injury, capillary integrity improves, and fluids start to return from the interstitial space to the vascular compartment. The kidneys begin to eliminate the excess fluid and solutes that have accumulated, including potassium. At this time, the patient’s potassium levels may drop significantly, especially if the patient is receiving diuretics, has had poor nutritional intake, or has ongoing fluid losses through burn wounds.
This drop in potassium during the fluid remobilization phase can result in hypokalemia, which can be dangerous. Symptoms may include muscle weakness, cardiac arrhythmias, and fatigue. Nurses must monitor serum potassium levels closely during this phase and administer potassium supplements if necessary.
In summary, the nurse should be most alert for hypokalemia during fluid remobilization, which is when the body begins reabsorbing fluids and electrolytes and renal excretion increases. This is the phase where potassium loss is most likely and clinically significant.