# A nurse is caring for a patient receiving morphine sulfate via patient-controlled analgesia (PCA) pump for postoperative pain management. Which nursing intervention is the priority to ensure patient safety?

> source: MyMerci (mymerci.kr)  
> url: https://mymerci.kr/pages/nclex_q.php?qn_id=543492  
> language: ko  
> subject: Pharmacology

## 문제

A nurse is caring for a patient receiving morphine sulfate via patient-controlled analgesia (PCA) pump for postoperative pain management. Which nursing intervention is the priority to ensure patient safety?

## 보기

1. Encourage the patient to use the PCA pump every 15 minutes to maintain adequate pain control
2. Assess the patient's pain level using a numeric rating scale every 2 hours during the day shift only
3. Monitor respiratory rate, depth, and oxygen saturation every 2 hours and before each dose administration **✔ 정답**
4. Instruct family members to press the PCA button when the patient appears uncomfortable or is sleeping

**정답: 3**

## 해설

Respiratory depression is the most serious adverse effect of opioids like morphine. Priority nursing intervention is monitoring respiratory rate, depth, and oxygen saturation every 2 hours and before each dose to detect early signs. Other options are unsafe or inadequate for safety monitoring.

## 심화 해설

Understanding the Priority: PCA Safety

When managing a patient with a patient-controlled analgesia (PCA) pump delivering morphine sulfate, the nurse's highest priority is preventing the most life-threatening adverse effect: opioid-induced respiratory depression. Morphine, a pure opioid agonist, acts on mu-opioid receptors in the central nervous system, which not only provides analgesia but also dose-dependently depresses the brainstem's respiratory centers, blunting its response to rising carbon dioxide levels. This can lead to progressive hypoventilation, hypoxia, and, if unmonitored, respiratory arrest. The clinical practice guideline for postoperative pain management emphasizes that effective acute pain management is a critical component of perioperative care and enhanced recovery after surgery (ERAS) [1]. However, the safe delivery of this therapy hinges on vigilant monitoring to mitigate the inherent risks of opioids.

Analysis of Options

Let's examine each intervention through the lens of patient safety and the principles of safe opioid administration.

*   Option 1 is incorrect and dangerous. A PCA pump is programmed with a lockout interval to prevent overdosing. Instructing a patient to use it every 15 minutes overrides this safety feature and the principle that the patient must be alert enough to self-administer. This practice can lead to stacking of doses and severe respiratory depression. The guidelines focus on standardized, safe protocols, not aggressive, unscheduled dosing [1].

*   Option 2 is incorrect because it is incomplete. While pain assessment is a core component of postoperative care and a goal of ERAS protocols to enhance recovery, assessing pain only during the day shift and only every 2 hours neglects the continuous nature of pain and the need for ongoing monitoring. More critically, it fails to address the priority safety parameter: respiratory status.

*   Option 3 is the correct answer. Monitoring respiratory rate, depth, and oxygen saturation is the cornerstone of safe opioid administration. A respiratory rate below 12 breaths per minute, shallow breathing, or declining oxygen saturation are early indicators of respiratory depression, allowing for timely intervention before a catastrophic event. This aligns directly with the guideline's focus on standardizing postoperative management to reduce complications and improve recovery [1].

*   Option 4 is incorrect and violates a fundamental PCA safety rule. The PCA button must only be pressed by the patient. This "PCA by proxy" is dangerous because a sedated or sleeping patient cannot feel the need for pain medication, and a family member's administration can easily lead to an opioid overdose and respiratory arrest.

Clinical Integration

The priority nursing action is a direct application of the nursing process: assessment before implementation. Before a patient receives any dose of an opioid, the nurse must first assess the patient's level of consciousness and respiratory status. The clinical practice guideline underscores that standardized, safe postoperative pain management is integral to reducing opioid consumption and shortening hospital stays, goals that are only achievable when safety monitoring is the unwavering priority [1]. The lockout interval on the PCA pump is a safety mechanism, but it is not a substitute for direct nursing assessment of the patient's physiological response to the medication. The nurse's clinical judgment in evaluating respiratory rate, depth, and oxygen saturation is the patient's primary safeguard against the life-threatening complication of opioid-induced respiratory depression.References (research sources)

- [1]Clinical practice guidelines for postoperative pain management in adults (2024 edition).GuidelineChen X, Chu Q, Peng Y, Chen Y, Kaye AD, Liu H, Yang J, Wang T, Yu W, Pain Group of the Chinese Society of Anesthesiology. (2025) · DOI: 10.1016/j.jatmed.2025.09.001

## 임상 시나리오

PCA Safety: Opioid Monitoring PriorityPreventing Respiratory Depression
The highest priority for a patient on a morphine PCA pump is monitoring for opioid-induced respiratory depression. Assess respiratory rate, depth, and oxygen saturation at least every 2 hours and before each dose.

A decreased respiratory rate, especially below 8-10 breaths/min, or dropping SpO2 is a late sign of impending respiratory arrest. Sedation level often precedes respiratory depression, so assess sedation using a valid scale like the Pasero Opioid-Induced Sedation Scale.

CautionOnly the alert patient should press the PCA button. Never allow family members to activate the pump, especially when the patient is sleeping. This "PCA by proxy" can lead to fatal oversedation.

## 핵심 개념

- **PCA pump** — Patient-Controlled Analgesia pump; a device allowing patients to self-administer pre-set doses of analgesic, typically with a lockout interval to prevent overdose.
- **Morphine sulfate** — A pure opioid agonist that acts on mu-receptors to provide analgesia but can cause dose-dependent respiratory depression by blunting the brainstem's response to CO2.
- **Respiratory depression** — A life-threatening adverse effect of opioids characterized by reduced respiratory rate, depth, and oxygen saturation, potentially leading to respiratory arrest.
- **Lockout interval** — A programmed safety feature on a PCA pump that sets a minimum time between doses, preventing the patient from administering another dose too soon.
- **Opioid-induced respiratory depression** — The most serious complication of opioid therapy, requiring vigilant monitoring of respiratory rate, depth, and oxygen saturation for early detection.

## 같은 주제 문제

- [A nurse is assessing a patient who has been receiving morphine sulfate 10 mg IV every 4 ho…](https://mymerci.kr/pages/nclex_q.php?qn_id=543489)
- [A nurse is assessing a patient who has been receiving morphine sulfate 10 mg IV every 4 ho…](https://mymerci.kr/pages/nclex_q.php?qn_id=543490)
- [A nurse is caring for a patient receiving morphine sulfate via patient-controlled analgesi…](https://mymerci.kr/pages/nclex_q.php?qn_id=543491)
- [A nurse is caring for a patient receiving hydromorphone via continuous intravenous infusio…](https://mymerci.kr/pages/nclex_q.php?qn_id=543493)
- [A nurse is caring for a patient receiving morphine sulfate via patient-controlled analgesi…](https://mymerci.kr/pages/nclex_q.php?qn_id=543494)
- [A nurse is caring for a patient receiving continuous morphine infusion for severe cancer p…](https://mymerci.kr/pages/nclex_q.php?qn_id=543495)
- [A nurse is assessing a patient who has been receiving morphine sulfate 10 mg IV every 4 ho…](https://mymerci.kr/pages/nclex_q.php?qn_id=543524)
- [A nurse is assessing a patient who has been receiving morphine sulfate 10 mg IV every 4 ho…](https://mymerci.kr/pages/nclex_q.php?qn_id=543525)

---

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

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