Patient-controlled and epidural analgesia: the nursing checks
- Safe practice
A pump gives pain medicine on demand or through an epidural catheter; the nurse double-checks settings and watches sedation, breathing and the block.
What it is
Patient-controlled analgesia (PCA) uses a programmed pump that lets the patient give themselves an opioid within set limits: a minimum time between doses and a maximum per hour, sometimes with a small continuous flow. Epidural analgesia delivers analgesic medicine through a catheter in the epidural space, as a continuous infusion, patient-controlled doses or both. The most serious risk of opioids is respiratory depression, and it is usually preceded by increasing sedation. Epidurals add low blood pressure, motor block, catheter problems and, rarely, infection or a haematoma that can compress the spinal cord. This page covers only the nursing checks: the drug, concentration and limits are set by the prescription and the institutional protocol.
What it requires
- A written order and an institutional protocol that set the drug, concentration, pump limits and monitoring.
- A dedicated, labelled line and a locked pump that only authorised staff can program.
- Teaching before starting: when and how to press the button, and what to report.
- Pain, sedation, respiratory rate and depth, oxygen saturation and blood pressure checked at the times the protocol sets.
- For an epidural: trained staff, a secured catheter with a visible site and the filter and labels the protocol requires.
Components
- PCA settings: the demand dose, the minimum interval between doses, the hourly limit and, in some patients, a continuous infusion.
- Epidural catheter: placed by the anaesthesia team; it may run as a continuous infusion, patient-controlled doses or both.
- Sedation scale: a validated tool such as the Pasero Opioid-Induced Sedation Scale (POSS) grades how easily the person wakes and stays awake.
- Sensory level: checked on both sides with something cold, noting the skin level where the person stops feeling it.
- Motor block: leg strength checked by asking the person to move the hips, knees and ankles.
How it is applied (and why)
- Check order, patient, drug, concentration and settings with a second nurse — pump programming errors can be fatal.
- Teach that only the patient presses the button — a drowsy patient stops pressing, which is a built-in safety stop.
- Score sedation with the agreed scale before counting breaths — sedation increases before breathing slows.
- Count rate and depth of breathing for a full minute and check saturation — slow or shallow breaths signal depression.
- Measure blood pressure and pulse on schedule, more often after a start or increase — epidurals can cause hypotension.
- Check the sensory level on both sides and leg strength — a block that rises or deepens needs action.
- Inspect the epidural site and dressing; confirm lines are labelled and secured — prevents infection and wrong-route errors.
- Ask about pain, nausea, itching and passing urine — these common effects guide the plan.
- At handoff, recheck settings and volume left with the next nurse and record — shows nothing changed between shifts.
In nursing practice
- Hard to wake, falls asleep mid-sentence, or slow, shallow breathing: stop the infusion as the protocol says, stay, stimulate the patient and call for urgent help.
- Low oxygen saturation that does not improve, or pauses in breathing: call the rapid response team.
- Low blood pressure, dizziness or fainting: lay the patient flat and call.
- With an epidural: new or severe back pain, leg weakness that keeps increasing, or loss of bladder or bowel control: emergency, call the anaesthesia team at once; delays worsen the outcome.
- Catheter disconnected, leaking or out, or redness or pus at the site: protect the site, follow the protocol and call.
Common mistakes
- Family or staff pressing the button so the patient can rest.
- Checking only the respiratory rate and missing increasing sedation.
- Accepting a pump setting without an independent second check.
- Getting the patient up to walk without first checking leg strength.
- Connecting another line or medicine to the epidural catheter.
Test yourself
Think of the answer, then tap the question to see it.
Who may press the PCA button?
Only the patient. If someone else presses it, the safety stop of a drowsy patient not pressing is lost.
Why is sedation assessed before the respiratory rate?
Because increasing sedation usually comes before opioid respiratory depression, so it is the earlier warning sign.
What does a sedation scale such as POSS assess?
How easily the person wakes and stays awake. Higher levels of sleepiness call for the actions in the protocol.
Which signs in a patient with an epidural need an immediate call?
New back pain, leg weakness that keeps increasing, loss of bladder or bowel control, or marked low blood pressure.
Connections
Educational content for students; it does not replace your institution's protocols, supervised clinical training or a prescriber's order. Dose-calculation examples use made-up numbers: they are educational, not a clinical order.
Sources: Nursing Fundamentals, 11.4: Pain Management (Open RN (Chippewa Valley Technical College), LibreTexts, 2021); Postoperative Thoracic Epidural Analgesia: Adverse Events from a Single-Center Series of 3126 Patients (Manassero A et al., Local and Regional Anesthesia) (Local and Regional Anesthesia (open access, PMC), 2020); Versão brasileira da Pasero Opioid-Induced Sedation Scale: estudo de adaptação transcultural (Leite SS et al.) (Revista Gaúcha de Enfermagem (open access), 2024); Neuraxial and Perineural Bleeding after Neuraxial Techniques: An Overview of the Last Year (De Cassai A et al.) (Eurasian Journal of Medicine (open access, PMC), 2020).
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Representative model, for educational purposes only.