Pupillary Pain Index to Evaluate Interscalene Block and Postoperative Pain in Patients Underwent Shoulder Surgery
Condition: Surgery; Shoulder Impingement
MeSH terms: Shoulder Impingement Syndrome
Study type: Observational

Summary: 
      When an individual encounters nociceptive pain stimuli, the pupil dilates in a unique manner
      known as Pupil reflex dilation (PRD).The degree of pupillary reflex dilatation can be further
      quantified into an objective parameter, termed the Pupillary pain index (PPI), as a
      monitoring tool for the balance between nociception and antinociception in surgical patients
      The motivation for this study is to investigate the feasibility of using pupillometry to
      assess acute pain after shoulder surgery. The purpose of the study is as follows: (1) Can PDR
      in patients undergoing general anesthesia be used to assess the analgesic effect of
      interscalene block? (2) Does PPI at the end of surgical anesthesia in such patients correlate
      with the first numerical pain scale (NRS) during the recovery room?
    

Detailed description: 
      When an individual encounters nociceptive pain stimuli, the pupil dilates in a unique way
      called pupillary reflex dilation (PRD), which can be observed both when the individual is
      awake or under anesthesia. The degree of pupillary reflex dilatation can be further
      quantified into an objective parameter called the Pupillary pain index (PPI), which serves as
      a monitoring tool for the balance between nociception and antinociception in surgical
      patients. Larson studied 32 female breast surgery patients who received general anesthesia
      combined with thoracic paravertebral nerve block on the affected side. The results showed
      that the affected side of the nerve block had significantly lower pupillary reflex dilation
      than those without nerve block on the healthy side of the breast. The authors believed that
      this study confirmed the value of pupillary reflex dilation in monitoring the success rate of
      unilateral thoracic paravertebral nerve block during general anesthesia. In a prospective
      observational study of 26 patients undergoing neurosurgery under general anesthesia,
      Pupillary pain index at the end of surgical anesthesia and Numerical Rating Scale (NRS)
      during the recovery room were recorded separately, The results showed a significant
      correlation between the two parameters (rS = 0.62; P = 0.002). The authors concluded that the
      application of the measurement of pupillary reflex dilation may be useful in predicting and
      preventing acute postoperative pain. Shoulder rotator muscle repair is a common surgery in
      our hospital. Patients must receive general anesthesia, sometimes combined with scalene
      interscalene block (ISB), to improve postoperative acute pain ,help to perform passive
      shoulder rehabilitation exercises and prevent shoulder joint adhesions. Based on the above
      literature review, the motivation for this study was to investigate the feasibility of using
      pupillometry to assess acute pain after shoulder surgery. The objectives of the research
      project are as follows: 1. Can pupillary reflex dilation in patients undergoing general
      anesthesia be used to assess the analgesic effect of scalene nerve block? 2. Is the pupillary
      pain index (PPI) at the end of surgical anesthesia correlated with the first numerical pain
      scale (NRS) during the recovery room in such patients?
    

Intervention name(s): Patients scheduled to undergo shoulder rotators repair surgery
Intervention type(s): Procedure
Intervention description(s): Patients scheduled to undergo shoulder rotators repair surgery, and received combined general anesthesia and interscalene block
Observational model: Case-Only
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Patients scheduled to undergo shoulder rotators repair surgery