Validation of a New "Objective Pain Score" Vs. "Numeric Rating Scale" For the Evaluation of Acute Pain: A Comparative Study.
BACKGROUND
Pain scores are used for acute pain management. The assessment of pain by the patient as well as the caregiver can be influenced by a variety of factors. The numeric rating scale (NRS) is widely used due to its easy application. The NRS requires abstract thinking by a patient to assign a score to correctly reflect analgesic needs, and its interpretation is subject to bias.


OBJECTIVE
The study was done to validate a 4-point objective pain score (OPS) for the evaluation of acute postoperative pain and its comparison with the NRS.


METHODS
A total of 1021 paired readings of the OPS and NRS of 93 patients who underwent laparotomy and used patient-controlled analgesia were evaluated. Acute pain service (APS) personnel recorded the OPS and NRS. Rescue analgesia was divided into two incremental levels (level 1-paracetamol 1 g for NRS 2 - 5 and OPS 3, Level 2-Fentanyl 25 mcg for NRS ≥ 6 and OPS 1 and 2). In cases of disagreement between the two scores, an independent consultant decided the rescue analgesia.


RESULTS
The NRS and OPS agreed across the range of pain. There were 25 disagreements in 8 patients. On 24 occasions, rescue analgesia was increased from level 1 to 2, and one occasion it was decreased from level 2 to 1. On all 25 occasions, the decision to supplement analgesia went in favor of the OPS over the NRS. Besides these 25 disagreements, there were 17 occasions in which observer bias was possible for level 2 rescue analgesia.


CONCLUSIONS
The OPS is a good stand-alone pain score and is better than the NRS for defining mild and moderate pain. It may even be used to supplement NRS when it is indicative of mild or moderate pain.
Department of Anesthesiology, Institute of Liver and Biliary Sciences, New Delhi, India.
Manish
M
Tandon
Department of Anesthesiology, Institute of Liver and Biliary Sciences, New Delhi, India.
Anshuman
A
Singh
Department of Anesthesiology, Institute of Liver and Biliary Sciences, New Delhi, India.
Vandana
V
Saluja
Department of Anesthesiology, Institute of Liver and Biliary Sciences, New Delhi, India.
Mandeep
M
Dhankhar
Department of Anesthesiology, Institute of Liver and Biliary Sciences, New Delhi, India.
Chandra Kant
CK
Pandey
Department of Biostatistics, Institute of Liver and Biliary Sciences, New Delhi, India.
Priyanka
P
Jain
Acute Pain Service; Pain Assessment; Postoperative Pain