Pain in critically ill patients in the intensive care unit (ICU) is common. However, pain assessment in critically ill patients often is complicated because these patients are unable to communicate ...effectively. Therefore, we designed a study (a) to determine the inter-rater reliability of the Numerical Rating Scale (NRS) and the Behavioral Pain Scale (BPS), (b) to compare pain scores of different observers and the patient, and (c) to compare NRS, BPS, and the Visual Analog Scale (VAS) for measuring pain in patients in the ICU.
We performed a prospective observational study in 113 non-paralyzed critically ill patients. The attending nurses, two researchers, and the patient (when possible) obtained 371 independent observation series of NRS, BPS, and VAS. Data analyses were performed on the sample size of patients (n = 113).
Inter-rater reliability of the NRS and BPS proved to be adequate (kappa = 0.71 and 0.67, respectively). The level of agreement within one scale point between NRS rated by the patient and NRS scored by attending nurses was 73%. However, high patient scores (NRS > or = 4) were underestimated by nurses (patients 33% versus nurses 18%). In responsive patients, a high correlation between NRS and VAS was found (rs = 0.84, P < 0.001). In ventilated patients, a moderate positive correlation was found between the NRS and the BPS (rs = 0.55, P < 0.001). However, whereas 6% of the observations were NRS of greater than or equal to 4, BPS scores were all very low (median 3.0, range 3.0 to 5.0).
The different scales show a high reliability, but observer-based evaluation often underestimates the pain, particularly in the case of high NRS values (> or = 4) rated by the patient. Therefore, whenever this is possible, ICU patients should rate their pain. In unresponsive patients, primarily the attending nurse involved in daily care should score the patient's pain. In ventilated patients, the BPS should be used only in conjunction with the NRS nurse to measure pain levels in the absence of painful stimuli.
Assessing pain in mechanically ventilated critically ill patients is a great challenge. There is a need for an adequate pain measurement tool for use in conscious sedated patients because of their ...questionable communicative abilities. In this study, we evaluated the use of the Behavioral Pain Scale (BPS) in conscious sedated patients in comparison with its use in deeply sedated patients, for whom the BPS was developed. Additionally, in conscious sedated patients, the combination of the BPS and the patient-rated Verbal Rating Scale (VRS-4) was evaluated.
We performed a prospective evaluation study in 80 nonparalyzed critically ill adult intensive care unit patients. Over 2 mo, nurses performed 175 observation series: 126 in deeply sedated patients and 49 in conscious sedated patients. Each observation series consisted of BPS ratings (range 3-12) at 4 points: at rest, during a nonpainful procedure, at retest rest, and during a routine painful procedure. Patients in the conscious sedated state also self-reported their pain using the 4-point VRS-4.
BPS scores during painful procedures were significantly higher than those at rest, both in deeply sedated patients (5.1 4.8-5.5 vs 3.4 3.3-3.5, respectively) and conscious sedated patients (5.4 4.9-5.9 vs 3.8 3.5-4.1, respectively) (mean 95% confidence interval). For both groups, scores obtained during the nonpainful procedure and at rest did not significantly differ. There was a strong correlation between nurses' BPS ratings and conscious sedated patients' VRS-4 ratings during the painful procedure (r(s) = 0.67, P < 0.001). At rest and during nonpainful procedures, 98% of the observations were rated as acceptable pain (VRS 1 or 2) by both nurses and patients. During painful procedures, nurses rated the pain higher than patients did in 16% of the observations and lower in 12% of the observations.
The BPS is a valid tool for measuring pain in conscious sedated patients during painful procedures. Thus, for noncommunicative and mechanically ventilated patients, it may be regarded as a bridge between the observational scale used by nurses and the VRS-4 used by patients who are able to self-report pain.
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