Acute Pain Assessment & Inpatient Analgesia
Multimodal pathways, safe prescribing, PCA monitoring, and when to escalate — evidence‑based guidance for student nurses.
Pain is universally designated as the fifth vital sign, yet on bustling acute trust wards, it remains one of the most frequently misassessed, poorly managed, and under‑treated clinical phenomena. For student and newly qualified nurses, managing acute pain involves far more than administering scheduled medications off a drug chart. Uncontrolled acute pain alters patients — it leads to withdrawal, anxiety, delirium, sleep deprivation, and slower recovery. This guide covers what you actually need to know, aligned with national standards.
1. National Clinical Framework
UK perioperative and acute pain management is guided by:
- NICE Guideline NG180 — Perioperative Care in Adults (published Aug 2020): Recommends multimodal analgesia, regular assessment, and structured pain relief pathways from admission through discharge.
📎 Source: NICE NG180 — Full Guideline
⚠️ Local prescribing policies and analgesia charts vary. Always follow your trust’s approved formularies and protocols alongside national guidance.
2. Acute vs. Chronic Pain — Know the Difference
Treating persistent pain the same way as acute tissue injury rarely works and can cause harm. The distinction matters:
| Feature | Acute Pain | Chronic (Persistent) Pain |
|---|---|---|
| Duration & Purpose | Days to weeks; protective warning of tissue damage | > 3–6 months past healing; no protective purpose |
| Mechanism | Mostly nociceptive — direct tissue stimulation | Often neuropathic or central sensitisation |
| Signs | Tachycardia, hypertension, sweating, distress | Few autonomic signs; fatigue, low mood, sleep disruption |
| Goal | Relieve while healing occurs; treat the cause | Function, coping, rehabilitation — not necessarily zero pain |
3. Assessment — Beyond the Number
Pain is personal. A score of 6 means different things to different people. Always combine the score with what you see and hear:
- Numerical Rating Scale (0–10): Best for alert, communicative adults. Ask what the number means to them.
- Verbal Descriptors: None → Mild → Moderate → Severe — clearer for some patients.
- Behavioural / Observational Tools (e.g. Abbey Pain Scale): Essential for patients with dementia, learning disabilities, or communication difficulty. Watch facial expression, movement, vocalisation, and change in behaviour.
Agitation in older inpatients is often untreated pain before it is anything else. Before sedation — assess, reassure, and relieve pain. Observe movement: guarding, slow movement, or holding a body part speaks louder than a score.
4. The Multimodal Analgesic Ladder
Combine drugs with different mechanisms — better relief, lower doses, fewer side effects. Review and step down as healing progresses:
Paracetamol 1g QDS — baseline for almost everyone. Check renal/GI/cardiac status before adding NSAIDs (ibuprofen, naproxen). Hold if dehydrated or AKI risk.
Codeine or tramadol for moderate pain. Add gabapentin/pregabalin if shooting/burning nerve pain — start low, titrate, watch drowsiness.
Oral morphine or oxycodone — start low, titrate responsibly. Shortest course, lowest effective dose. Review regularly; prevent dependence.
Patient‑Controlled Analgesia pumps or epidural infusions — managed with the Acute Pain Team. Strict safety monitoring applies.
5. When to Escalate — The Acute Pain Team
Uncontrolled pain after 2–3 reviews, complex history, opioid tolerance, or PCA/epidural issues — involve the team early. Don’t wait.
- PCA — Only the patient presses the button. Never a relative or a nurse. Lockout intervals prevent overdose but cannot prevent over‑administration by others.
- Epidural — Check: BP, motor power (Bromage score), sensory level, and bladder emptying. Report hypotension, weakness, or numbness promptly.
- Sedation first — then breathing. Rising sedation score is the earliest warning of respiratory depression. If drowsy — stop, rouse, escalate.
6. Opioid Safety & Respiratory Depression
Opioid‑induced respiratory depression is rare but life‑threatening. Sedation always precedes falling respiratory rate — that is your warning window:
- Respirations < 8–10/min, slow/shallow breathing, pin‑point pupils, drowsiness that won’t rouse → stop infusion, call for help, give oxygen, prepare naloxone.
- Document sedation score alongside pain score and respiratory rate — every 1–4 hours depending on risk.