Chest Wall Block After Sternotomy: Randomized Controlled Trial in Cardiac Surgery: (PABLOS Study)

Each year, more than one million patients worldwide undergo cardiac surgery via sternotomy. Postoperative pain is frequent in this context, affecting 49% of patients at rest and 78% during mobilization. This pain is associated with many avoidable post-operative complications.

Nowadays, ERAS (Enhanced Rehabilitation After Surgery) protocols are increasingly developed in order to optimize post-operative rehabilitation. The management of postoperative pain is one of their main challenges and is based in particular on the use of locoregional anesthesia (LRA) with the aim of sparing morphine.

Several LRAs have been described in cardiac surgery in recent years, and they are increasingly used in routine clinical practice. Transverse thoracic block and parasternal block are the main peripheral LRA techniques proposed for surgical procedures with sternotomy. Transverse chest block was first described in cardiac surgery in 2015 ; and the parasternal block in 2018. These techniques are spreading in current clinical practice because of their simplicity of implementation, their safety and their supposed effectiveness. The parasternal block is more recent, and presents a more superficial injection plane than the transverse thoracic block. Thus, it is theoretically as effective as the transverse thoracic and less at risk of complications.

The main objective of this study is to compare the effectiveness of LRA (bilateral transverse thoracic block or bilateral parasternal block) in addition to standard management compared to standard management alone (general anesthesia without LRA) on the quality of early postoperative recovery after heart surgery by sternotomy.

The primary endpoint is the postoperative recovery score in the French version, FQoR-15 (French Quality of Recovery - 15 score), performed at H+24. The FQoR-15 is currently one of the most reliable and reproducible tools for assessing the quality of postoperative rehabilitation. This instrument is one of the recommended endpoints for the evaluation of patient comfort, according to a recent consensus of international experts.

This study is a phase III study of superiority, monocentric, comparative, with three parallel groups, randomized with a ratio (1:1:1), controlled versus standard care, single-blind. of inclusion is 254 patients included and randomized.

The patient is pre-included during the pre-anaesthetic visit, the day before his scheduled surgery. He receives oral and written information, and provides his written consent to participate in this study, the follow-up will be 30 days. Depending on the randomization, the patient receives one of the following three treatments:

• bilateral transverse thoracic block followed by standard analgesic management;
• a bilateral parasternal block followed by standard analgesic treatment;
• standard analgesic treatment alone (without LRA). Bilateral parasternal block or transverse thoracic block are performed ultrasound-guided, at the end of surgery in the operating room. Once in the desired plane depending on the randomisation (transverse or parasternal), a volume of 20 ml of ropivacaine at 2 mg/ml is injected on each side of the sternum. The rest of the pain management is identical in the three groups according to the habits of the department.

If the hypotheses on the effectiveness of parasternal block and/or transverse thoracic block are confirmed, postoperative recovery in the interventional arms will be improved. This will confirm the value of performing an LRA postoperatively.

Pre-inclusion criteria :

• Adult patient (≥18 years old);
• Patient having scheduled cardiac surgery with a sternotomy performed at the CHU d'Angers;
• Patient having signed a consent;
• French-speaking patient, able to understand and answer a questionnaire;
• Affiliated patient or beneficiary of a social security scheme.

Criteria for confirming inclusion

• Hemodynamic stability at the end of surgery;
• Absence of bleeding justifying immediate revision surgery.

Non-inclusion criteria

• Known hypersensitivity to amide-bonded local anesthetics;
• Operation for cardiac revision surgery, including sternotomy REDUX (revision surgery);
• Emergency surgery;
• Surgery in a septic context (Endocarditis, Intravascular device infection);
• Weight less than 30kg;
• Severe psychiatric or cognitive impairment interfering with assessment by questionnaires;
• Pregnant, breastfeeding or parturient woman;
• Person deprived of liberty by judicial or administrative decision;
• A person undergoing psychiatric treatment under duress;
• Person subject to a measure of legal protection;
• Inclusion in another interventional study modifying postoperative pain management.