A patient is receiving Extracorporeal Membrane Oxygenation (ECMO) with stable machine settings. Suddenly, the patient’s oxygen saturation drops to 85%. What should be the priority nursing action?

Appeared in: NORCET 9 Mains - 2025

Explanation

The nursing process prioritizes assessment before intervention. A sudden change in the patient's condition requires the nurse to first assess the situation to identify the cause.
In a patient on ECMO, the circuit functions as their artificial lungs. A sudden drop in oxygen saturation, despite stable machine settings, strongly suggests a failure within the ECMO circuit itself.
The most common and life-threatening circuit failure causing hypoxemia is clot formation within the oxygenator (membrane lung), which obstructs gas exchange.
Therefore, the priority is to rapidly assess the circuit for clots, kinks, or other signs of malfunction before considering other interventions.

Option A: This is an implementation step that bypasses the crucial assessment phase. Changing ventilator settings is unlikely to be effective if the ECMO oxygenator has failed and may delay the correct intervention.
Option B: Administering oxygen via a face mask is insufficient for a patient requiring ECMO support. It fails to address the root cause, which is a critical failure in the primary life-support system.
Option D: This action would be fatal. ECMO is the patient's life support. Abruptly discontinuing it would lead to immediate cardiorespiratory arrest.

Clinical Relevance

Nursing practice connection: Safe nursing care depends on performing Priority nursing action for acute hypoxemia in a patient on ECMO in the correct sequence, documenting the action clearly, and monitoring for the expected response.
ECMO is a high-risk, high-acuity therapy. Nurses must be vigilant for signs of circuit failure, as these are life-threatening emergencies.
Regularly checking the ECMO circuit for clots (visible as dark streaks in the oxygenator) and monitoring pressures (like the transmembrane pressure gradient) are key nursing responsibilities.
What if? - If the patient's blood pressure also dropped suddenly along with the SpO2, the priority would broaden to assess for both oxygenator failure and pump failure or cannula dislodgement, as these can cause both hypoxemia and hemodynamic collapse.

How to Approach the Question

First, identify the core clinical problem: a patient on advanced life support (ECMO) has a sudden, critical desaturation (SpO2 85%).
Note the key context: the ECMO machine settings are stable. This clue directs your thinking away from simple setting errors and towards a new, acute problem.
Apply the nursing process (ADPIE). In any acute crisis, assessment is the first and most critical step. The priority action must be an assessment.
Evaluate the options based on this principle. Option C is an assessment. Options A, B, and D are implementations.
Eliminate the implementation options that are illogical or dangerous. Increasing ventilator FiO2 (A) ignores the ECMO circuit. A face mask (B) is inadequate. Discontinuing ECMO (D) is fatal. This leaves the assessment action (C) as the only correct and safe choice.

Concept Tested & Keywords

Concept Tested: Priority nursing action for acute hypoxemia in a patient on ECMO.
Stem keywords: Extracorporeal Membrane Oxygenation (ECMO), oxygen saturation drops, 85%, priority nursing action, stable machine settings
Lead-in keywords: What should be the priority
Clinical cues: Sudden drop in SpO2 to 85%: Indicates an acute, severe failure in oxygenation.
Clinical cues: Stable machine settings: Rules out simple setting errors and points towards a new mechanical or patient problem.

QE1snCHbP1KU84GjmbEN-7

E6 Medicine Harrison 22e Part 2 p. 213-215

Practise the full NORCET 9 Mains - 2025

Attempt every question from this paper in a timed mock, then review the full solution for each one.