Pain management nursing: complete reference guide

Pain is the most common reason patients seek healthcare, and nurses are its primary managers at the bedside. Effective pain management is a core nursing competency and a patient right — the Joint Commission requires hospitals to assess, treat, and reassess pain as part of standard care. Nurses assess pain before and after every intervention, titrate analgesics, monitor for adverse effects, implement non-pharmacological strategies, and document the full cycle. Getting this right requires command of assessment tools, pharmacological mechanisms, opioid safety protocols, and multimodal approaches. This reference covers all of it in one place. Use it alongside the OLDCARTS mnemonic guide, PQRST mnemonic guide, and nursing pharmacology reference.

Quick reference: pain assessment scales

Different clinical contexts require different tools. Self-report scales are preferred whenever the patient can communicate; behavioral scales are used when they cannot.

Scale	Full name	Range	Best used for	Limitation
NRS	Numeric Rating Scale	0–10	Cognitively intact adults and older children	Requires numeric abstraction; unreliable in moderate cognitive impairment
VAS	Visual Analog Scale	0–100 mm line	Research settings, adults	Requires fine motor ability to mark the line; not ideal at bedside
FACES	Wong–Baker FACES Pain Rating Scale	0–10 (6 faces)	Children ≥3 years, adults with language barriers	May be influenced by emotional expression rather than pain intensity
FLACC	Face, Legs, Activity, Cry, Consolability	0–10	Infants, preverbal children, cognitively impaired adults	Limited validity in adults who cannot demonstrate pediatric behaviors (e.g., crying)
BPS	Behavioral Pain Scale	3–12	Intubated, sedated ICU patients	Does not assess muscle tension; slightly less comprehensive than CPOT
CPOT	Critical-Care Pain Observation Tool	0–8	Ventilated and non-ventilated critically ill adults	Score ≥3 indicates clinically significant pain; requires training for consistency

Use FLACC for pediatric and cognitively impaired patients. Use CPOT or BPS for intubated ICU patients — both are validated behavioral tools with published reliability data (AACN, 2024). NRS remains the default for communicative adult patients in most US inpatient settings.

Pain types and pathophysiology

Understanding pain classification guides both assessment and treatment selection. Pain is broadly categorized by duration (acute vs. chronic) and by mechanism (nociceptive vs. neuropathic vs. mixed).

Acute vs. chronic pain

Acute pain is time-limited, typically lasting less than three months, and has an identifiable cause — surgical incision, trauma, inflammation, or procedure. It serves a biologically protective function (alerting the body to tissue damage) and resolves as healing occurs. Physiologic indicators — tachycardia, hypertension, diaphoresis, facial grimacing, guarding — are often present early but diminish over time even if pain persists, making vital signs unreliable as a standalone assessment tool.

Chronic pain persists beyond three months or beyond the expected course of tissue healing. It may be driven by ongoing disease (cancer, arthritis, diabetic neuropathy) or by central and peripheral sensitization that persists after the original injury resolves. Patients with chronic pain often lack the sympathetic activation seen in acute pain, which can lead clinicians to underestimate its severity. Psychosocial factors — depression, anxiety, catastrophizing, sleep disruption — significantly amplify chronic pain and must be addressed alongside physical treatment.

Nociceptive pain

Nociceptive pain results from activation of peripheral nociceptors by actual or threatened tissue damage. It subdivides into:

Somatic pain — arises from skin, muscle, bone, or joints. Typically well-localized, aching, or throbbing. Examples: postoperative incision pain, fracture pain, osteoarthritis.
Visceral pain — arises from internal organs. Poorly localized, cramping, pressure-like; often referred to distant sites. Examples: appendicitis, bowel obstruction, renal colic.

Neuropathic pain

Neuropathic pain results from damage or dysfunction in the peripheral or central nervous system. Characteristic descriptors include burning, shooting, stabbing, electric shock–like, or “pins and needles.” It may coexist with allodynia (pain from non-painful stimuli) or hyperalgesia (exaggerated pain from normally painful stimuli). Examples include diabetic peripheral neuropathy, post-herpetic neuralgia, chemotherapy-induced neuropathy, and radiculopathy. Standard opioids provide incomplete relief for neuropathic pain — adjuvant medications targeting the nervous system are typically required.

Mixed pain

Many clinical conditions involve both nociceptive and neuropathic components — chronic low back pain, cancer pain, and complex regional pain syndrome all fall into this category. Treatment must address both mechanisms.

Pain assessment

OLDCARTS applied to pain

The OLDCARTS framework provides systematic pain history collection. Applied to pain specifically:

Onset — when did it start? Sudden (vascular event, perforation) vs. gradual (inflammation, cancer)?
Location — point to it. Localized vs. diffuse? Any radiation pattern?
Duration — constant, intermittent, or episodic? How long does each episode last?
Character — ask the patient to describe it without prompting. Aching, burning, stabbing, cramping, pressure, electric?
Aggravating factors — movement, position, inspiration, eating, activity, palpation?
Relieving factors — rest, ice, heat, positioning, prior medications?
Timing — worse at certain times of day? Related to meals, bowel function, activity?
Severity — rate 0–10. Functional impact: can you sleep? Walk to the bathroom?

The PQRST mnemonic (Provocative/Palliative, Quality, Region/Radiation, Severity, Timing) covers similar ground and is widely used in cardiac and acute care settings.

Behavioral indicators

When patients cannot self-report, assess for: facial grimacing or furrowing of brows; guarding or bracing; restlessness, agitation, or resistance to movement; moaning, grunting, or calling out; changes in muscle tone (rigidity or flaccidity); and changes in vital signs compared to baseline (tachycardia, hypertension, tachypnea). Behavioral indicators indicate that pain is present but do not quantify it — document the behaviors observed, not a numeric score derived from vital signs alone.

Special populations

Pediatric patients. Use FLACC for infants and children unable to self-report. Children ≥3 years can typically use the FACES scale. Children ≥8 years can use the NRS. Review the pediatric nursing reference and vital signs by age for age-appropriate baselines.

Cognitively impaired adults. Use FLACC or the Pain Assessment in Advanced Dementia (PAINAD) scale. Behavioral observation is the primary method — ask caregivers about the patient’s typical pain behaviors and what usually brings relief.

Intubated or sedated patients. Use CPOT (preferred) or BPS. Assess before and after suctioning or repositioning, which are common procedural pain triggers. Integrate pain assessment with the sedation assessment — see the ICU nursing reference for the ABCDEF bundle.

Pharmacological management

Analgesic selection follows the principle of matching the agent to the mechanism and severity of pain. The three major classes are non-opioid analgesics, opioid analgesics, and adjuvant (co-analgesic) agents.

Class	Mechanism	Examples	Nursing considerations	Key contraindications/cautions
Acetaminophen	Central COX inhibition, serotonergic pathways	Tylenol; often combined with opioids (Percocet, Vicodin)	Max 4 g/day total from all sources; reduce to 2 g/day in hepatic impairment or heavy alcohol use; check all combination products for hidden acetaminophen	Hepatic impairment; acetaminophen allergy
NSAIDs	Peripheral and central COX-1/COX-2 inhibition; reduce prostaglandin synthesis	Ibuprofen, ketorolac (IV), naproxen, celecoxib (COX-2 selective)	Administer with food or antacid; monitor renal function, BP, GI symptoms; ketorolac limited to ≤5 days IV due to GI/renal risk	Renal impairment, peptic ulcer disease, bleeding risk, heart failure, NSAID allergy; avoid in pregnancy third trimester
Opioids – weak	Mu-opioid receptor agonism; modulate pain transmission in spinal cord and brain	Tramadol, codeine	Tramadol lowers seizure threshold; codeine requires CYP2D6 for activation — ultra-metabolizers at risk of toxicity, poor metabolizers get no benefit; avoid codeine in children post-tonsillectomy	Seizure disorder (tramadol); CYP2D6 variability (codeine); avoid with MAOIs (tramadol)
Opioids – strong	Full mu-opioid receptor agonism	Morphine, oxycodone, hydromorphone, fentanyl, methadone	Titrate to effect; monitor sedation (POSS), respiratory rate, oxygen saturation; have naloxone at bedside; start bowel regimen at initiation; reassess every 15 min (IV) or 30 min (oral) after administration	Respiratory depression, severe bronchospasm; methadone: QT prolongation risk, complex dosing — specialist consultation recommended
Adjuvants: gabapentinoids	Inhibit voltage-gated calcium channels; reduce neuronal excitability	Gabapentin, pregabalin	Effective for neuropathic pain; dose-reduce in renal impairment; sedation and dizziness common especially in elderly; do not stop abruptly	Renal impairment (dose adjust); fall risk in elderly
Adjuvants: SNRIs/TCAs	Inhibit serotonin/norepinephrine reuptake; descending pain modulation	Duloxetine (SNRI), amitriptyline (TCA), nortriptyline (TCA)	TCAs have significant anticholinergic effects; use low doses for pain (10–75 mg); SNRIs preferred in elderly; monitor mood and suicidality at initiation	TCAs: cardiac conduction abnormalities, glaucoma, urinary retention; SNRIs: serotonin syndrome risk with concurrent serotonergic agents
Adjuvants: local anesthetics	Sodium channel blockade; interrupt peripheral nerve conduction	Lidocaine patch (topical), bupivacaine (regional), lidocaine IV infusion	Lidocaine patch: apply to intact skin, max 3 patches ×12 hours on/12 hours off; IV lidocaine requires cardiac monitoring; regional blocks managed with anesthesia/pain service	Lidocaine patch: broken skin; IV lidocaine: cardiac arrhythmia risk
Adjuvants: corticosteroids	Reduce inflammation and peritumoral edema	Dexamethasone, methylprednisolone	Short-term use for inflammatory or oncologic pain; monitor blood glucose (especially in diabetics); do not stop abruptly after extended use	Uncontrolled diabetes, active infection, GI ulcer without PPI coverage

Opioid safety essentials

Opioids are effective for moderate-to-severe acute pain and cancer pain, but carry significant risks. The nurse’s role is continuous monitoring and early intervention before complications become life-threatening.

Pasero Opioid-Induced Sedation Scale (POSS)

Assess sedation with every opioid administration and at each pain reassessment. The POSS is validated specifically for opioid-induced sedation — unlike RASS, it focuses on unintended sedation rather than sedation targeted therapeutically.

POSS level	Description	Nursing action
S	Sleep, easy to arouse	Acceptable; no action required — reassess with next scheduled assessment
1	Awake and alert	Acceptable; continue monitoring per protocol
2	Slightly drowsy, easily aroused	Acceptable for most patients; monitor closely; decrease opioid dose if clinically appropriate
3	Frequently drowsy, arousable, drifts off during conversation	Unacceptable; hold opioid; notify provider; increase monitoring frequency; oxygen if SpO2 declining
4	Somnolent, difficult to arouse	Unacceptable — respiratory emergency. Hold all opioids; stimulate vigorously; apply oxygen; prepare naloxone; notify provider immediately; consider code team

Sedation precedes respiratory depression — POSS level 3 or 4 is a warning to act before apnea occurs.

Respiratory monitoring

Assess respiratory rate and depth, not just rate. A rate of 12 breaths/min with shallow, irregular breathing is more concerning than a rate of 10 with deep, regular breaths. Continuous pulse oximetry is standard for patients on opioid infusions or PCA. Capnography (end-tidal CO2) is more sensitive for early hypoventilation than SpO2 alone and should be used when available for high-risk patients. See head-to-toe assessment for full respiratory assessment technique.

Naloxone reversal protocol

Naloxone (Narcan) reverses opioid-induced respiratory depression by competitive antagonism at mu-opioid receptors. Standard reversal protocol for respiratory depression:

Stimulate the patient (sternal rub, call by name)
Apply supplemental oxygen; open airway; prepare for bag-mask ventilation
Dilute naloxone 0.4 mg in 9 mL normal saline (0.04 mg/mL)
Administer 0.04–0.08 mg IV every 2–3 minutes until respiratory rate >8/min and patient arousable
Observe for re-narcotization — naloxone half-life (30–90 min) is shorter than most opioids; a second dose or infusion may be required
Document time, dose, patient response; notify provider; assess for precipitating cause (accidental overdose, dose error, drug accumulation)

Avoid precipitating acute withdrawal in opioid-tolerant patients by titrating naloxone in small increments — full reversal in a dependent patient causes severe pain, agitation, pulmonary edema, and sympathetic storm.

Constipation prophylaxis

Opioid-induced constipation results from mu-receptor activation in the GI tract and does not resolve with tolerance over time. Start a stimulant laxative (senna, bisacodyl) at opioid initiation — do not wait for constipation to develop. A stool softener alone (docusate) is insufficient. For refractory opioid-induced constipation, peripherally acting mu-opioid receptor antagonists (PAMORAs) such as methylnaltrexone or naloxegol are options.

Equianalgesic dosing

When rotating opioids (switching from one to another due to inadequate analgesia or intolerable side effects), use equianalgesic conversion tables as a starting point, then reduce the calculated dose by 25–50% to account for incomplete cross-tolerance. Always consult pharmacy for complex rotations. Never convert methadone using standard equianalgesic tables — methadone has highly variable and unpredictable conversions; specialist consultation is required.

Non-pharmacological interventions

Non-pharmacological strategies complement rather than replace analgesics. They reduce pain intensity, lower analgesic requirements, improve patient satisfaction, and have minimal adverse effects. They are appropriate across all pain types and settings.

Intervention	Mechanism	Evidence level	Nursing implementation
Cold therapy (cryotherapy)	Vasoconstriction; reduces edema and nerve conduction velocity	Strong for acute musculoskeletal and post-surgical pain	Apply cold pack with cloth barrier; limit to 15–20 min per application; do not apply directly to skin or over impaired sensation
Heat therapy	Vasodilation; promotes muscle relaxation and increased tissue extensibility	Strong for muscle spasm, chronic musculoskeletal pain	Moist heat preferred; limit to 15–20 min; avoid over wounds, impaired circulation, or areas of reduced sensation
Positioning and repositioning	Reduces pressure on injured or inflamed tissues; decreases muscle tension	Strong (standard practice)	Reposition every 2 hours; use pillows to support injured limbs; elevate edematous extremities; see patient positioning
Distraction	Activates descending inhibitory pathways; redirects attention from pain	Moderate	Engage patient in conversation, music, television, reading, games; particularly effective during procedures
Relaxation techniques	Reduces sympathetic activation and muscle tension; activates parasympathetic response	Moderate	Deep breathing (4-7-8 pattern), progressive muscle relaxation, guided imagery scripts; nurse initiates at bedside or refers to therapy
Music therapy	Activates endogenous opioid release; reduces anxiety	Moderate	Patient-selected music via headphones; 20–30 min sessions; evidence strongest for procedural and postoperative pain
TENS (transcutaneous electrical nerve stimulation)	Gate control theory; inhibits afferent pain signal transmission	Moderate for chronic musculoskeletal pain	Applied by physical therapy or trained nurse; electrode placement varies by pain location; contraindicated over pacemakers, broken skin, near carotid sinus
Guided imagery	Redirects cognitive focus; activates relaxation response	Moderate	Walk patient through a calm, detailed mental scene; can be recorded for self-administration; particularly useful for procedural and chronic pain
Massage	Stimulates mechanoreceptors; reduces muscle tension; promotes relaxation	Moderate	Gentle effleurage appropriate at bedside; avoid over wounds, DVT-suspected limbs, or areas of infection; refer to massage therapist for structured sessions
Acupuncture	Modulates endogenous pain inhibitory systems (proposed); neuroimmune interactions	Moderate (growing evidence for chronic pain, migraines, chemotherapy-related neuropathy)	Requires trained practitioner; refer through integrative medicine or pain service

Multimodal analgesia

Multimodal analgesia means using two or more analgesic agents or techniques with different mechanisms of action simultaneously. The goal is additive or synergistic pain relief with lower doses of each agent — particularly lower opioid doses, reducing opioid-related adverse effects.

WHO analgesic ladder

The World Health Organization’s three-step analgesic ladder was developed originally for cancer pain but is now applied broadly:

Step 1 (mild pain, NRS 1–3): Non-opioid analgesics — acetaminophen, NSAIDs — with or without adjuvants
Step 2 (moderate pain, NRS 4–6): Weak opioids (tramadol, low-dose codeine) added to non-opioids, with or without adjuvants
Step 3 (severe pain, NRS 7–10): Strong opioids (morphine, oxycodone, hydromorphone, fentanyl) with non-opioids and adjuvants

Clinical practice increasingly moves patients to Step 3 more rapidly for severe acute pain rather than requiring sequential failure at each step. The ladder is a guide, not a rigid protocol.

Balanced analgesia in postoperative care

Enhanced Recovery After Surgery (ERAS) protocols use scheduled acetaminophen, scheduled NSAIDs (unless contraindicated), regional anesthesia (nerve blocks, neuraxial techniques), and opioids only for breakthrough pain. This approach consistently reduces opioid consumption, speeds return of bowel function, and shortens hospital stay. Nurses implement this by administering scheduled non-opioid doses proactively and using opioids as rescue rather than primary agents.

Patient-controlled analgesia (PCA) nursing responsibilities

PCA delivers IV opioid on patient demand within programmed limits, supplemented by a basal (continuous) infusion in some protocols. Core nursing responsibilities include:

Pre-PCA: confirm the order (drug, concentration, demand dose, lockout interval, basal rate if ordered, 1-hour and 4-hour limits); verify programming with a second nurse per policy; educate the patient — they control the button, no one else
During PCA: assess pain score, sedation (POSS), respiratory rate, and SpO2 at minimum every 4 hours (or per policy); assess PCA attempts vs. deliveries to gauge efficacy; inspect IV site; ensure line is not obstructed
Monitoring for complications: excessive sedation (POSS ≥3), respiratory depression (RR <8/min or SpO2 <92%), nausea/vomiting, pruritus, urinary retention, and PCA misuse (proxy dosing by family members — a significant safety concern)
Documentation: record demand doses, delivered doses, pain scores, sedation scores, and any interventions

Nursing responsibilities and documentation

Reassessment timing

Reassessment after intervention is non-negotiable — the analgesic was given; now confirm whether it worked. Standard timeframes:

IV opioid or IV analgesic: reassess within 15–30 minutes
Oral analgesic or IM injection: reassess within 60 minutes
Non-pharmacological intervention: reassess within 30 minutes
Ongoing stable pain: reassess every 4–8 hours per unit protocol or with every change in condition

Documentation requirements

Document: pain score before intervention; intervention administered (drug, dose, route, time); pain score at reassessment; patient response (functional improvement, side effects); any escalation or provider notification. The SBAR communication framework structures escalation calls effectively — include the pain trajectory, analgesics given and response, current sedation level, and your specific request.

Escalation criteria

Notify the provider when: pain is not controlled after two doses of ordered analgesic; POSS level 3 or 4; respiratory rate <10/min or SpO2 <92% in a patient on opioids; new or significantly changed pain character (possible new pathology); patient requests a change in their pain management plan. Document each escalation call and the provider’s response.

Pain management intersects with nearly every clinical domain. Explore these related pages for deeper clinical context: