# Situation: A 46-year-old woman with severe community-acquired pneumonia and septic shock is in the intensive care unit (ICU). On day 2 she is intubated and diagnosed with acute respiratory distress syndrome (ARDS): her chest X-ray shows bilateral opacities, and an echocardiogram shows normal heart function. She is 160 cm tall and weighs 82 kg. The ventilator's high-pressure alarm sounds, and her oxygen saturation has fallen from 93% to 89%. The nurse hears coarse rhonchi over the trachea and breath sounds on both sides; the trachea is midline, and her blood pressure is unchanged at 112/68 mmHg. The endotracheal tube is not kinked, and she is not biting it. A closed in-line suction catheter is attached to the circuit. What should the nurse do?

> source: MyMerci (mymerci.kr)  
> url: https://mymerci.kr/pages/nclex_q.php?qn_id=629881  
> language: ko  
> subject: Nursing Practice III — Care of Clients with Problems in Surgery, Oxygenation, Fluid and Electrolytes, Infectious, Inflammatory and Immunologic Response, Cellular Aberrations

## 문제

Situation: A 46-year-old woman with severe community-acquired pneumonia and septic shock is in the intensive care unit (ICU). On day 2 she is intubated and diagnosed with acute respiratory distress syndrome (ARDS): her chest X-ray shows bilateral opacities, and an echocardiogram shows normal heart function. She is 160 cm tall and weighs 82 kg.

The ventilator's high-pressure alarm sounds, and her oxygen saturation has fallen from 93% to 89%. The nurse hears coarse rhonchi over the trachea and breath sounds on both sides; the trachea is midline, and her blood pressure is unchanged at 112/68 mmHg. The endotracheal tube is not kinked, and she is not biting it. A closed in-line suction catheter is attached to the circuit. What should the nurse do?

## 보기

1. Ask the physician to raise the end-expiratory pressure
2. Prepare for needle decompression of a tension pneumothorax
3. Suction with the closed in-line catheter without opening the circuit **✔ 정답**
4. Disconnect the circuit and give breaths with a manual bag, then suction

**정답: 3**

## 해설

A high-pressure alarm with coarse tracheal rhonchi points to secretions in the airway; breath sounds on both sides, a midline trachea, and a stable blood pressure make a tension pneumothorax unlikely, and the tube is neither kinked nor bitten. In ARDS, opening the circuit loses positive end-expiratory pressure and collapses recruited alveoli, so the nurse suctions with a closed in-line catheter. Disconnecting and bagging is reserved for when the cause of the alarm cannot be found quickly.

## 심화 해설

The high-pressure alarm on a mechanical ventilator signals that the ventilator is encountering increased resistance to delivering a breath. In this patient, the coarse rhonchi heard over the trachea are the key clinical clue: they indicate the presence of thick secretions or fluid within the large airways. Because breath sounds are present bilaterally, the trachea remains midline, and blood pressure is stable, a tension pneumothorax is unlikely. Similarly, the endotracheal tube is not kinked and the patient is not biting it, so a mechanical obstruction of the tube itself can be ruled out. The most probable cause of the sudden rise in airway pressure and the drop in oxygen saturation from 93% to 89% is an accumulation of secretions partially occluding the airway and triggering the alarm.

In a patient with ARDS who is dependent on positive end-expiratory pressure (PEEP) to keep alveoli recruited, disconnecting the ventilator circuit causes an immediate loss of PEEP and can lead to rapid alveolar derecruitment and worsening hypoxemia. For this reason, the closed in-line suction catheter is the preferred method for clearing secretions in this setting. The closed system allows suctioning to occur without breaking the circuit, thereby preserving PEEP, maintaining lung volume, and minimizing the risk of oxygen desaturation during the procedure.

A randomized controlled trial comparing open versus closed suctioning in ARDS patients ventilated with PEEP of 5–10 cmH2O supports this approach [1]. The study examined lung volume and oxygenation outcomes and found that closed suctioning better preserved the benefits of PEEP compared with open suctioning, which requires circuit disconnection. Although the abstract does not report the full numerical results, the rationale for closed suctioning in ARDS is directly aligned with the physiological principle of avoiding alveolar collapse.

Additional evidence reinforces the safety and clinical utility of closed-system suctioning. A prospective observational study found that closed-system suctioning can be performed in mechanically ventilated patients while allowing assessment of subjective dyspnea, indicating that the procedure is feasible and does not inherently destabilize the patient when used appropriately [2]. Furthermore, research using deep learning to detect respiratory circuit events identified fluid accumulation as a common and clinically significant problem during mechanical ventilation, with 91.7% of patients exhibiting circuit events . This underscores that secretion accumulation is a frequent trigger for ventilator alarms and should be addressed promptly with suctioning.

A bench study on secretion movement during mechanical ventilation also highlights the clinical importance of retained airway secretions as a contributor to ventilator-associated pneumonia and other complications . While that study focused on a different ventilation mode, it reinforces the principle that clearing secretions is a priority when airway resistance increases.

Watch out! Disconnecting the circuit and providing manual breaths with a bag is reserved for situations in which the cause of the high-pressure alarm cannot be quickly identified or the patient is in immediate danger of losing the airway. In this scenario, the cause is identifiable—secretions—and the patient is hemodynamically stable, so disconnection is not indicated.

Key point! The sequence of assessment findings directs the intervention: high-pressure alarm plus coarse rhonchi equals secretions; bilateral breath sounds, midline trachea, and stable blood pressure rule out tension pneumothorax; ARDS with PEEP dependence means the circuit must remain closed. Therefore, suctioning with the closed in-line catheter without opening the circuit is the correct and safest action.References (research sources)

- [1]Open versus closed suctioning on lung volume and oxygenation in ARDS patients with PEEP 5-10 cmH2O: A randomized controlled trial.RCT/clinical trialGao H, Ying Y, Yang J. (2026) · DOI: 10.1371/journal.pone.0351172

- [2]Impact of closed-system suctioning on self-reported dyspnea in mechanically ventilated patients: a prospective observational study.Research articleLiang L, Wang S, Liang Z, Qiu X, Xie S, Xu J. (2026) · DOI: 10.3389/fmed.2026.1834389

## 임상 시나리오

High-Pressure Alarm in ARDS: Suction Without Breaking the CircuitPrioritize closed in-line suction to clear secretions while preserving PEEP
A high-pressure alarm with coarse rhonchi over the trachea strongly suggests airway secretions. Bilateral breath sounds, a midline trachea, and stable blood pressure make tension pneumothorax unlikely.

In ARDS, the patient depends on PEEP to keep alveoli recruited. Use a closed in-line suction catheter to clear secretions without opening the circuit, preventing alveolar derecruitment and worsening hypoxemia.

CautionDo not disconnect the circuit for suctioning or manual bagging unless the cause of the alarm cannot be quickly identified. Circuit disconnection causes immediate loss of PEEP and can precipitate rapid oxygen desaturation in ARDS patients.

## 핵심 개념

- **ARDS** — Acute respiratory distress syndrome; bilateral lung opacities with non-cardiogenic pulmonary edema causing severe hypoxemia.
- **PEEP** — Positive end-expiratory pressure; maintains alveolar recruitment and oxygenation, especially in ARDS.
- **High-pressure alarm** — Ventilator alarm triggered by increased airway resistance, often from secretions, kinking, biting, or pneumothorax.
- **Closed in-line suction** — Suction catheter attached to the ventilator circuit allowing secretion removal without disconnecting the circuit.
- **Tension pneumothorax** — Life-threatening air trapping in the pleural space causing tracheal deviation, absent breath sounds, and hypotension.

## 같은 주제 문제

- [Situation: A 24-year-old woman with asthma is brought to the emergency room (ER) with whee…](https://mymerci.kr/pages/nclex_q.php?qn_id=629676)
- [Situation: A 24-year-old woman with asthma is brought to the emergency room (ER) with whee…](https://mymerci.kr/pages/nclex_q.php?qn_id=629677)
- [Situation: A 24-year-old woman with asthma is brought to the emergency room (ER) with whee…](https://mymerci.kr/pages/nclex_q.php?qn_id=629678)
- [Situation: A 24-year-old woman with asthma is brought to the emergency room (ER) with whee…](https://mymerci.kr/pages/nclex_q.php?qn_id=629679)
- [Situation: A 36-year-old woman comes to the Rural Health Unit (RHU), which provides free t…](https://mymerci.kr/pages/nclex_q.php?qn_id=629680)
- [Situation: A 36-year-old woman comes to the Rural Health Unit (RHU), which provides free t…](https://mymerci.kr/pages/nclex_q.php?qn_id=629681)
- [Situation: A 36-year-old woman comes to the Rural Health Unit (RHU), which provides free t…](https://mymerci.kr/pages/nclex_q.php?qn_id=629682)
- [Situation: A 22-year-old tall, thin man who smokes is admitted to the surgical ward with a…](https://mymerci.kr/pages/nclex_q.php?qn_id=629683)

---

More free questions: [기출문제](https://mymerci.kr/)

_학습 참고용입니다. 실제 임상은 최신 지침과 소속 기관 프로토콜을 따르세요._