Correlation Between NOL Index After Stimulus and Post-operative Opioid, Pain, Pre-operative Phenotype

Correlation Between NOL Index After Stimulus and Post-operative Opioid, Pain, Pre-operative Phenotype

Correlation Between NoL Index Response to Standardized Stimulus Under General Anesthesia and: Post-operative Opioid Consumption and Pain, Pre-operative Phenotype and Pain Biomarkers

This study evaluates the correlation between NoL index response to standardized stimulus under general anesthesia and the post-operative pain, assessed by opioid consumption and numerical pain scores after video-assisted thoracoscopy (VATS).

The NoL index, a nociception monitor using a multiparametric approach, has shown an excellent sensitivity and specificity in detecting noxious stimuli under general anesthesia. This monitor is better than any other parameter in grading nociception under general anesthesia. More recently, it has recently been shown a strong correlation between NoL index response to nociceptive stimulus and the level of opioid analgesia during surgery. No study has evaluated that NoL could predict post-operative pain so far. It has not yet been proven that NoL was correlated with post-operative opioid consumption or with post-operative pain scores. Some phenotypic factors were previously shown to correlate with post-operative pain and opioid consumption, such as psychological factors and tests, or also assessment of some pre-operative nociceptive thresholds (NT). Pain catastrophizing was proven in several studies to correlate with acute post-operative pain. So far, no study compared each of these preoperative psychological factors or nociceptif thresholds to the NoL index response to intraoperative standardized pain stimulus in terms of correlation with post-operative opioid requirements and pain scores. Moreover, there is no study evaluating the pro-inflammatory protein profiles that might likely be correlated to inter-individual differences in NoL response after this standardized nociceptive stimulus under general anesthesia. This study will assess the level of correlation between NoL index response to standardized stimulus under general anesthesia and the post-operative pain, assessed by opioid consumption and numerical pain scores after video-assisted thoracoscopy (VATS). It also evaluates the correlation between NoL index response to standardized stimulus under general anesthesia and pre-operative phenotype and post-operative pain biomarkers.

There is only one arm in this study. Intervention will be electrical forearm stimulus under general anesthesia and the response of NOL index following this stimulus and its correlation with postoperative parameters such as pain and opioid consumption in post anesthesia care unit.

The "intervention" is not a drug, but it is standardized electrical stimulus applied with a muscle relaxation monitor on the forearm of the anesthetized patient. The NoL index is registered in response to this stimulus in an observational manner. Device: Device PMD200TM offering intraoperative NoL Index

Nociceptive threshold for pressure, heat and electrical stimulation are associated with post-operative pain and will be assessed preoperatively to see if there is correlation between them and the NOL index response to the nociceptive stimulus (see intervention 1)

Some biomarkers of inflammation and endogenous opioids are associated with post-operative pain. Blood samples will be withdrawn at D0 before surgery starts, D1 (H24) and D2 (H48) after surgery to see if they correlate with NOL changes after the stimulus described in intervention 1 above

Correlation between NoL index absolute values after electrical stimulus under general anesthesia and Total hydromorphone consumption (PACU and PCA) 24h after surgery

Pain scores from 0 to 10 after surgery, using numerical rating scale in post anesthesiology care unit

Correlation between NoL index absolute values after electrical stimulus under general anesthesia and Pain scores after surgery, in post anesthesiology care unit

Correlation between NoL index absolute values after electrical stimulus under general anesthesia and Pain scores (NRS) at H24 at rest

Correlation between NoL index absolute values after electrical stimulus under general anesthesia and Pain scores (NRS) at H24 while coughing

Correlation between NoL index absolute values after electrical stimulus under general anesthesia and Pain scores (NRS) at H48 at rest

Correlation between NoL index absolute values after electrical stimulus under general anesthesia and Pain scores (NRS) at H48 while coughing

Correlation between NoL index absolute values after electrical stimulus under general anesthesia and total hydromorphone consumption (mg) in PACU

Correlation between NoL index absolute values after electrical stimulus under general anesthesia and total hydromorphone consumption (mg) at H48

Correlation between Pain catastrophizing scale from 0 to 50 and Total (hydromorphone consumption at day 1 24 hours)

Correlation between pre-operative Pain catastrophizing scale and NoL index absolute values after electrical stimulus under general anesthesia

Correlation between pre-operative State-Trait anxiety Inventory and NoL index absolute values after electrical stimulus under general anesthesia

Correlation between State-Trait anxiety Inventory from 0 to 80 and Total hydromorphone consumption at H24

Inclusion Criteria: Adult patient (Age 18 or older) ASA status I, II or III elective video assisted thoracoscopy under general anesthesia Exclusion Criteria: history of coronary artery disease serious cardiac arrhythmia (including atrial fibrillation), history of substance abuse, chronic use of psychotropic and/or opioid drugs, use of drugs that act on the autonomic nervous system (including β-blockers), history of psychiatric diseases, allergy to any drug used in the study protocol, refusal of the patient unexpected difficult airway requesting excessive, possibly painful airway manipulations unexpected intraoperative complications requiring strong hemodynamic support (transfusions, vasopressors, inotropes) conversion to thoracotomy