Clinical Utility of the Numerical Verbal Scale (NVS) and the Pain and Functional Activity Scale (PFAS) in the Management of Rescue Analgesia in Acute Postoperative Pain. Randomized Study.

Overview

Adequate postoperative pain management, along with mobilization and early oral nutrition, is the foundation for optimal recovery after surgery. Unidimensional pain scales (Numerical Verbal Rating Scale - NRS, Visual Analogue Scale - VAS, Categorical Scale - CRS, Facial Pain Scale - FPS) do not adequately reflect a patient's actual analgesic needs. Basing analgesic treatment on the classic algorithm of administering opioids if pain is greater than 4 on the NRS, without considering functional impairment, has been shown to be a cause of overtreatment in surgical wards. The Functional Activity Score (FAS) is the simplest scale, designed for bedside application and geared toward therapeutic decision-making. R: Able to perform any activity; B: Pain prevents some activity; C: Unable to perform any activity. Given the need to standardize functional limitation when measuring postoperative pain, we propose the Pain and Functional Activity Scale (PFAS), which combines the NVA (Non-Visual Analogue Scale) with the Functional Activity Scale. Specifically, pain on movement would be recorded using the NVA in motion (NVAm), along with functional limitation (A, B, or C). The rescue analgesia treatment algorithm adapted to the PFAS would involve treating patients with pain greater than 4 on the NVA whenever it represents a severe limitation of their functional activity (C). In this study, we aim to evaluate whether there are significant differences in the proportion of patients who meet the criteria for needing rescue analgesia according to the NVA compared to the proportion of patients who meet the criteria for needing rescue analgesia established by the PFAS, during the 2-day postoperative period. To this end, an experimental, longitudinal, prospective, randomized, single-blind study for the data analyzer will be carried out, where a group that will receive rescue analgesia if VNS\>4 and another if VNSm\>4 + FAS C will be compared in the first two days of postoperative surgical patients of the surgeries selected in the EOXI of Vigo.

Interventions

• Procedure Group A: Rescue analgesia if NVS>4
  Rescue analgesia will be self-administered by the patient, when post-surgical pain is moderate to severe, using morphine PCA at a dose of 0.075 mg/kg maximum every 15 minutes, up to a maximum of 3 times per hour, provided they meet the criteria described for the group to which they have been assigned.
• Procedure Group B: Rescue analgesia if NVSm > 4 + FAS C
  Rescue analgesia will be self-administered by the patient, when post-surgical pain is moderate to severe and this pain interferes with and limits functional activity, using morphine PCA at a dose of 0.075 mg/kg maximum every 15 minutes, up to a maximum of 3 times per hour, provided they meet the criteria described for the group to which they have been assigned.

Primary outcome measures

• NVS [Time frame: Day 0 (before the surgical intervention), at 24 and 48 hours and in case rescue analgesia is requested.]
• mNVS [Time frame: Day 0 (before the surgical intervention), at 24 and 48 hours and in case rescue analgesia is requested.]
• FAS [Time frame: Day 0 (before the surgical intervention), at 24 and 48 hours and in case rescue analgesia is requested.]

Secondary outcome measures (12)

• Age [Time frame: Day 0 (before the surgical intervention)]
• Gender [Time frame: Day 0 (before the surgical intervention)]
• BMI [Time frame: Day 0 (before the surgical intervention)]
• Pfeiffer [Time frame: Day 0 (before the surgical intervention)]
• ASA [Time frame: Day 0 (before the surgical intervention)]
• Risk factors associated with persistent postoperative pain [Time frame: Day 0 (before the surgical intervention)]
• Procedure [Time frame: Day 1 (after the surgical intervention)]
• Surgery location [Time frame: Day 1 (after the surgical intervention)]
• Anesthetic technique [Time frame: Day 1 (after the surgical intervention)]
• Intraoperative analgesia guidelines [Time frame: Day 1 (after the surgical intervention)]
• Confusión Assessment Method (CAM) [Time frame: at 24 and 48 hours]
• Analgesia guidelines in the post-surgical intensive care unit [Time frame: at 24 and 48 hours]

Eligibility criteria

Inclusion criteria

• Scheduled surgery with VATS admission
• Age > 18 years
• Signed informed consent

Exclusion criteria

• Cognitive-mental deficit assessed using the Pfeiffer questionnaire. Patients with more than two errors if they have a university degree and more than three errors if they do not have a university degree are excluded from the study.
• Allergy to any of the analgesic drugs listed on the data collection sheet (Paracetamol / NSAIDs / Metamizole / Dexamethasone / Local anesthetics / Morphine / Fentanyl).
• Patients who, in the preoperative survey, present any degree of functional limitation according to the FAS scale (Grade B and C).

Withdrawal Criteria:

• If the patient withdraws consent.
• If the patient experiences delirium, as measured by a positive CAM (Confusion Assessment Method) scale, following surgery.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: Yes

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Single blind

Primary purpose

Prevention

Study locations

Spain · 1 center

• Hospital Álvaro Cunqueiro — Vigo

Identifiers

NCT: NCT07310953 · EVN/EDAF · 2025/306

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗