BPS-NI Scoring and Interpretation
The Behavioral Pain Scale for Non-Intubated patients (BPS-NI) is scored from 3 to 12, with three domains assessed (facial expression, upper limb movements, and vocalization), where scores ≥5 indicate clinically significant pain requiring intervention. 1
Scale Components and Scoring
The BPS-NI evaluates three behavioral domains, each scored 1-4 points 2:
- Facial Expression: Relaxed (1), partially tightened/grimacing (2), fully tightened/eyelid closing (3), or grimacing with tears (4) 2
- Upper Limb Movements: No movement (1), partially bent (2), fully bent with finger flexion (3), or permanently retracted (4) 2
- Vocalization: Normal tone or no sound (1), sighing/moaning (2), crying out/sobbing (3), or screaming/grunting (4) 2
Total scores range from 3 (no pain) to 12 (maximum pain). 2, 3
Clinical Interpretation and Cut-Off Values
For non-intubated ICU patients, use these evidence-based thresholds 4:
- Score 3: No pain (baseline) 2
- Score ≥4: Moderate pain—consider analgesic intervention 4
- Score ≥5: Severe pain—immediate analgesic therapy required 4
The BPS-NI demonstrates excellent discriminative validity, with significantly higher scores during painful procedures (median 6.0) versus rest (median 3.0). 2
Psychometric Properties and Validation
The BPS-NI has good psychometric properties with a weighted score of 14.8, making it one of the two most validated tools for non-communicative ICU patients. 1
Key performance metrics include 2, 3:
- Inter-rater reliability: Weighted kappa 0.82-0.89 (excellent agreement) 2, 3
- Internal consistency: Cronbach's alpha 0.79-0.80 2, 3
- Responsiveness: Effect size 1.5-3.6 (highly responsive to pain changes) 2
Clinical Application Guidelines
Use BPS-NI for non-intubated ICU patients who cannot self-report pain, including those with delirium. 1
The Society of Critical Care Medicine guidelines specifically recommend BPS-NI alongside CPOT as having the greatest validity and reliability for monitoring pain in critically ill adults unable to self-report. 1
Assessment Timing
- At rest (baseline measurement)
- Before procedures (pre-intervention baseline)
- During nociceptive procedures (turning, wound care, catheter changes)
- 10 minutes after procedures (to assess analgesic effectiveness)
Special Populations
Brain-injured patients: BPS-NI is feasible and reliable, though pain behaviors may predominantly reflect level of consciousness rather than grimacing or muscle rigidity. 1
Patients with delirium: The scale was specifically validated in this population (84% CAM-ICU positive), demonstrating that pain during procedures is perceived even in delirious patients. 2
Important Clinical Caveats
The BPS-NI requires observable behaviors—it cannot be used in deeply sedated or paralyzed patients. 1
Self-report remains the gold standard when possible—always attempt to obtain patient self-report using the 0-10 Numeric Rating Scale before defaulting to behavioral assessment. 1
Validated translations exist in Mandarin, making it applicable across diverse patient populations. 1
The BPS-NI shows superior inter-rater reliability compared to other behavioral scales like NVPS (weighted kappa 0.81 vs 0.71), making it more reliable for consistent pain assessment across different evaluators. 3