MCID and PASS for Acute Pain and Quality of Recovery After Orthopedic Surgery

* Baseline demographic data * Baseline physiological variables (blood pressure, heart rate, respiratory rate, oxygen saturation) * Baseline investigations (hemoglobin, coagulation profile, serum electrolytes) if appropriate. * Preoperative pain state using NRS (0-10) * Preoperative functional state using the QoR-15 questionnaire * Pain expectation - patients will be asked preoperatively with the question "In a scale from 0 to 10 (where 0 = no pain and 10 = worst pain imaginable), what do you consider is an acceptable pain score for your first (and second) day after surgery?... Two weeks after surgery?" * Pain castastrophizing scale

All study patients will be managed per routine clinical practice and institutional standard for the performed surgery.

postoperative pain will be managed on the ward using a multimodal analgesic regimen as appropriate. This includes: 1. acetaminophen 650 - 1,000 mg given orally every 6 hours around the clock 2. NSAIDs e.g., celecoxib or other agents given orally around the clock per clinical guideline; omit if contraindicated or per surgeon's preference 3. Opioids e.g., hydromorphone 1-2 mg or oxycodone 15-30 mg given orally every 1-2 hours as required by the patient per standard nurse administered analgesic protocol. 4. In the event of severe pain refractory to the above treatments, the patient will be offered IV opioid e.g., intermittent doses of 0.2-0.4 mg hydromorphone IV every 10 minutes until pain becomes tolerable

Pain assessment using NRS pain scores (0 = no pain and 10 = worst possible pain) will be performed by an independent research staff, starting immediately in the PACU and serially over the first 48 hours after surgery or until hospital discharge.

Also, the degree of pain relief after treatment is assessed using a subjective 15-point Global Rating Scale (GRS) as mentioned above (Background). This is performed at the same time of each NRS assessment and a minimum of twice daily

During each NRS pain assessment before or after an analgesic intervention on POD 0, 1 and 2, the patient will also be asked this question- ""In your opinion, do you consider your current pain state satisfactory after your operation?" Patients giving a positive response are considered having an acceptable pain state. The PASS is the 75th centile for the pain NRS score in those with a satisfactory pain state.

The quality of recovery 15 questionnaire (QoR-15) to measure the dimension of quality of recovery will be administered once in the morning of POD 1 and POD 2. The MCID and PASS for QoR are determined in the same way as for NRS score. The final MCID value will be average of 4 values, 1 generated by the anchor based method and 3 generated by the distribution based method. The PASS for QoR is the 75th centile of the QoR-15 score in those patients who rated their recovery as good.

Additionally, opioid related adverse effects e.g., nausea, vomiting, itchiness, constipation, sedation (RASS + Ramsay)/ and respiratory depression will be assessed daily.