During the first 24 hours after a major burn injury, which of the following should the nurse anticipate?

GMCH Nursing Officer-2025

Medical & Surgical Nursing

Hard

Appeared in: GMCH Nursing Officer-2025

Explanation

The correct option is Hyperkalemia and metabolic acidosis.
In the first 24 hours (emergent phase) after a major burn, massive cell destruction occurs, releasing large amounts of intracellular potassium into the bloodstream, causing hyperkalemia.
Simultaneously, fluid shifts lead to hypovolemic shock and poor tissue perfusion. This forces cells into anaerobic metabolism, producing lactic acid and causing metabolic acidosis.
This combination of high potassium and an acidotic state is a hallmark of the initial response to severe burns.

Option A: Metabolic alkalosis is incorrect. The primary acid-base imbalance in the emergent phase is metabolic acidosis due to hypoperfusion and lactic acid accumulation.
Option B: Hypokalemia is incorrect for the initial 24-hour period. Hyperkalemia is the expected finding due to cell lysis.
Option D: Respiratory alkalosis is incorrect. The primary disturbance is metabolic acidosis. While hypocalcemia can occur, it is not the most defining feature paired with the acid-base status in this phase.

Visual 1: Flowchart - A flowchart illustrating the pathophysiology of burn shock. It would start with 'Major Burn Injury' and branch into 'Massive Cell Destruction' leading to 'Hyperkalemia', and 'Increased Capillary Permeability' leading to 'Hypovolemia', 'Poor Tissue Perfusion', and finally 'Metabolic Acidosis'.

Clinical Relevance

Nursing practice connection: Safe nursing care depends on performing Pathophysiological changes during the emergent phase of a major burn injury in the correct sequence, documenting the action clearly, and monitoring for the expected response.
Hyperkalemia is a life-threatening emergency as it can cause fatal cardiac dysrhythmias. Nurses must prioritize continuous cardiac monitoring for patients in the emergent phase of a burn.
The primary nursing intervention is aggressive fluid resuscitation (e.g., using the Parkland formula) to correct hypovolemia, restore tissue perfusion, and thereby help correct the metabolic acidosis.
What if? If the question asked about the period 72 hours after the burn, the nurse should anticipate hypokalemia. This is due to the fluid shifting back into the vascular space (diuresis) and the kidneys excreting excess potassium.

How to Approach the Question

First, identify the key timeframe in the question: 'first 24 hours'. This corresponds to the emergent or resuscitative phase of burn injury.
Recall the two primary pathophysiological events of this phase: 1) massive cell damage and 2) a major fluid shift causing hypovolemic shock.
Connect the pathophysiology to the lab values. Massive cell damage releases intracellular contents, primarily potassium, leading to hyperkalemia.
Connect the fluid shift and shock to its metabolic consequence. Hypovolemia leads to poor perfusion, forcing cells to use anaerobic metabolism, which produces lactic acid, resulting in metabolic acidosis.
Evaluate the options to find the one that correctly combines these two expected findings: Hyperkalemia and metabolic acidosis.

Concept Tested & Keywords

Concept Tested: Pathophysiological changes during the emergent phase of a major burn injury
Stem keywords: major burn injury, first 24 hours
Lead-in keywords: anticipate
Clinical cues: Timeframe: 'first 24 hours' points to the emergent/resuscitative phase of burn injury.

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