Superficial Parasternal Intercostal Plane Block in Cardiac Surgery Trial

This trial is comparing the use of 0.2% ropivacaine and 0.9% saline through a parasternal intercostal plane block and to measure whether there are any tangible changes in: 1. The primary outcome will be cumulative postoperative opioid use (measured as Milligram Morphine Equivalent (MME)) up to 72 hours following catheter insertion. Secondary outcomes will be: 2. cumulative postoperative opioid use from catheter insertion up to hospital discharge - measured as MME 3. median pain score - measured at rest and with coughing using a standardized numerical rating scale - for 72 hours post catheter insertion 4. delirium - assessed twice daily using institutional scores up to 72 hours following catheter insertion. 5.) Quality of Recovery -15 (QoR-15) score 24-96 hours post-surgery Tertiary outcomes will be: 6.) time from catheter insertion to extubation 7.) time from catheter insertion to first opioid analgesic provision following extubation 8.) time from catheter insertion to mobilization 9.) lengths of stay in the intensive care unit and the hospital 10.) postoperative nausea and vomiting - measured twice a day and antiemetic medication requirements for the 72 hours after catheter insertion 11.) opioid requirements following discharge from the hospital 12.) chronic post-sternotomy pain/disability (McGill Pain Questionnaire) 13.) participant-reported outcomes (PROMIS-29 survey) at 6 weeks and 3 months post surgery