# Situation: A 34-year-old man is admitted to the intensive care unit (ICU) after an intentional overdose of an unknown drug with aspiration of gastric contents. He is intubated and receiving mechanical ventilation. The consultation–liaison psychiatry team will see him once he is awake. The ventilator's high-pressure alarm sounds repeatedly. The nurse suctions the endotracheal tube and obtains scant secretions; the tubing is not kinked and holds no condensed water, and a bite block is in place. The alarm continues, he is agitated, and his oxygen saturation by pulse oximetry (SpO2) falls from 96% to 86%. Which action is BEST now?

> source: MyMerci (mymerci.kr)  
> url: https://mymerci.kr/pages/nclex_q.php?qn_id=630162  
> language: ko  
> subject: Nursing Practice V — Care of Clients with Maladaptive Patterns of Behavior; Care of Clients with Life-Threatening Conditions, Acute Multi-Organ Problems, High Acuity and Emergency Situations

## 문제

Situation: A 34-year-old man is admitted to the intensive care unit (ICU) after an intentional overdose of an unknown drug with aspiration of gastric contents. He is intubated and receiving mechanical ventilation. The consultation–liaison psychiatry team will see him once he is awake.

The ventilator's high-pressure alarm sounds repeatedly. The nurse suctions the endotracheal tube and obtains scant secretions; the tubing is not kinked and holds no condensed water, and a bite block is in place. The alarm continues, he is agitated, and his oxygen saturation by pulse oximetry (SpO2) falls from 96% to 86%. Which action is BEST now?

## 보기

1. Raise the high-pressure alarm limit so ventilation can continue
2. Ventilate him by manual bag with 100% oxygen and call for help **✔ 정답**
3. Give the prescribed sedative bolus for ventilator dyssynchrony
4. Suction again with a larger catheter and a longer suction pass

**정답: 2**

## 해설

When a ventilator alarm persists, the usual causes have been checked, and oxygenation is falling, the nurse disconnects the client from the ventilator, ventilates him with a manual resuscitation bag on 100% oxygen and calls the respiratory therapist and physician. This restores oxygenation at once and separates a ventilator problem from a client problem.

## 심화 해설

When a mechanically ventilated patient develops a persistently high-pressure alarm, the immediate priority is to determine whether the problem lies with the ventilator circuit or with the patient’s own airway and lung mechanics. In this scenario, the nurse has already performed the standard first-line checks: suctioning the endotracheal tube yielded only scant secretions, the tubing is not kinked and contains no condensed water, and a bite block is in place. Despite these interventions, the alarm continues, the patient becomes agitated, and SpO2 falls from 96% to 86%. This combination of persistent alarm plus progressive hypoxemia signals a failure to deliver adequate ventilation and oxygenation through the current ventilator setup, and it demands immediate disconnection and manual ventilation.

The best action is to ventilate the patient manually with a bag-valve-mask device on 100% oxygen while calling for help. Manual bagging accomplishes two critical goals at once. First, it restores oxygenation and ventilation without delay, bypassing whatever mechanical or patient-related factor is triggering the high-pressure alarm. Second, it serves as a diagnostic maneuver: if bagging is easy and the chest rises with normal resistance, the problem is more likely in the ventilator or circuit; if bagging is difficult or resistance is high, the problem is more likely within the patient—such as bronchospasm, pneumothorax, mucous plugging deeper in the airway, or endotracheal tube displacement or obstruction. This separation of ventilator problem from patient problem is a core principle in ventilator alarm management.

The high-pressure alarm specifically indicates that the pressure required to deliver a set tidal volume has exceeded the preset limit. Common causes include biting the endotracheal tube, kinked tubing, water in the circuit, secretions or mucus plugs, bronchospasm, pneumothorax, decreased lung compliance, and patient-ventilator asynchrony. The nurse has already ruled out several of these. The falling SpO2 is the key finding that escalates the situation from “troubleshoot the alarm” to “the patient is not being adequately oxygenated right now.” Watch out! A high-pressure alarm with worsening hypoxemia is never managed by simply raising the alarm limit, because that would mask a real ventilation failure and allow the patient to deteriorate further.

The consultation–liaison psychiatry context is relevant to the patient’s history of intentional overdose and aspiration, but it does not change the immediate airway and oxygenation priority. Agitation in this setting may reflect hypoxemia, pain, or ventilator dyssynchrony, but treating agitation with a sedative bolus before ensuring adequate oxygenation would be unsafe. Key point! Hypoxemia itself causes agitation; sedating a hypoxemic, agitated patient without first correcting oxygenation can precipitate respiratory arrest.

The scoping review on patient-ventilator asynchrony [1] reinforces that asynchrony is common, difficult to detect at the bedside, and associated with prolonged ventilatory support and increased mortality. However, asynchrony is a diagnosis of exclusion in the acute setting—it should be considered only after mechanical causes and life-threatening patient causes have been addressed. The review emphasizes that low recognition by healthcare professionals contributes to poor outcomes, which supports the principle of systematic, stepwise troubleshooting rather than assuming the alarm is a nuisance or simply due to patient fighting the ventilator.

The safety communication regarding Draeger Evita and Savina ventilators [2] adds an important nuance: after certain circuit disconnections during a high-pressure event, these ventilators may continue to display a high-airway-pressure alarm even when the actual problem is now a disconnected circuit with low pressure. This means the displayed alarm may not reflect the true current state of the circuit. A persistent high-pressure alarm that does not resolve with basic checks should prompt the nurse to verify the integrity of the entire breathing circuit and consider disconnecting the patient from the ventilator. Manual bagging is precisely the intervention that both verifies the patient can be ventilated and removes the ventilator from the equation while help is summoned.

The other options are incorrect for specific reasons. Raising the high-pressure alarm limit would allow the ventilator to continue cycling at dangerously high pressures, increasing the risk of barotrauma and volutrauma, while doing nothing to improve oxygenation. Giving a sedative bolus for presumed ventilator dyssynchrony addresses agitation but not the underlying cause of the high-pressure alarm or the falling SpO2, and it carries the risk of respiratory depression. Suctioning again with a larger catheter and longer suction pass is not indicated because the first suction attempt yielded scant secretions, and aggressive or prolonged suctioning can cause mucosal injury, vagal stimulation, and worsening hypoxemia—especially when the primary problem has not been identified.

The sequence of actions in this emergency is: disconnect from the ventilator, begin manual bagging with 100% oxygen, call for the respiratory therapist and physician, and then continue the systematic assessment of the patient and equipment while oxygenation is maintained. This approach prioritizes patient safety and reflects the standard of care for ventilator alarm emergencies.References (research sources)

- [1]Challenges and strategies for the identification and correction of patient-ventilator asynchronies in daily practice: a scoping review.Research articlePopayán AME, Vaporidi K, Parada-Gereda HM, Blanch L. (2026) · DOI: 10.4266/acc.006050

- [2]Draeger Medical Evita and Savina ventilators may incorrectly display high-airway-pressure alarm following some circuit disconnections.Research article(2011)

## 임상 시나리오

Ventilator High-Pressure Alarm with HypoxiaImmediate response when standard checks fail
When a high-pressure alarm persists after suctioning, checking the tubing, and confirming the bite block, and SpO2 falls below baseline, the priority is to disconnect the ventilator and begin manual bag-valve ventilation with 100% oxygen.

Manual bagging serves two purposes: it restores oxygenation immediately and acts as a diagnostic maneuver. Easy bagging with normal chest rise suggests a ventilator or circuit problem; difficult bagging suggests a patient problem such as bronchospasm, pneumothorax, or a displaced endotracheal tube.

CautionDo not raise the alarm limit or give sedatives first. These actions delay correction of hypoxia and may mask a life-threatening problem. Always call for help while initiating manual ventilation.

## 핵심 개념

- **High-pressure alarm** — Ventilator alarm triggered by increased airway resistance or decreased compliance, such as kinked tubing, secretions, bronchospasm, or pneumothorax.
- **Manual bag-valve ventilation** — Disconnecting the patient from the ventilator and ventilating with a self-inflating bag on 100% oxygen to restore oxygenation and diagnose the source of the problem.
- **Ventilator dyssynchrony** — A mismatch between the patient's breathing efforts and the ventilator's delivered breaths, often causing agitation and high-pressure alarms.
- **SpO2** — Peripheral oxygen saturation measured by pulse oximetry; a falling SpO2 indicates worsening hypoxemia.

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