The sternotomy site is the most painful area after cardiac surgery. Erector spinae plane block is effective in thoracic and abdominal surgery, but literature is lacking in cardiac surgery. The bilateral erector spinae plane block could reduce pain at rest and during mobilization, reduce opioids consumption, decrease postoperative complications, improve respiratory outcomes and improve patient comfort and satisfaction. The research hypothesis is that a single shot bilateral erector spinae plane block could reduce pain during mobilization during the first 48 hours after cardiac surgery performed with sternotomy

Background:

Pain after cardiac surgery is mostly localized at the sternotomy site. To improve postoperative pain management a number of technics involving loco-regional anesthesia have been developed. The epidural analgesia is the gold standard but the risk of epidural hematoma with heparinization in this surgery avoids its utilization in clinical practice. The paravertebral block can be used equally but there is a risk of pneumothorax. The erector spinae plane block could be a solution as it is a more superficial block. It's efficacity was proven in thoracic and abdominal surgery, but literature is lacking in cardiac surgery. A bilateral erector spinae plane block after cardiac surgery could significantly reduce pain at rest and during mobilization, reduce opioids consumption, decrease postoperative complications, improve respiratory outcomes and improve patient comfort and satisfaction.

The main objective of this to study is to examine the efficacity of a single-shot bilateral erector spinae plane block on pain reduction during mobilization during the first 48 hours after cardiac surgery compared to a control group.

The primary outcome:

Pain scale at patient mobilization during the first postoperative 48 hours measured by numerical pain scale.

Study design:

Prospective, randomized, doubled-blinded, single-center controlled trial with two groups:

1. The ropivacaine group (42 patients): a bilateral erector spinae block will be performed after patient arrival in the intensive care unit before wake up from anesthesia with 20ml of Ropivacaine 2mg/ml bilaterally.
2. The control group (42 patients): a sham block will be performed bilaterally in the same conditions.

Inclusion Criteria:

• Patients who undergo scheduled cardiac surgery with sternotomy for aortic or mitral valve replacement either by biological or mechanical prothesis, coronary arterial bypass surgery (CABG).
• Body Mass Index between 18,5 and 33kg/m² (extremity excluded)
• Patients who have given their consent according to the methods described in Title II of the book of the first Public Health Code
• Possession of Social Security insurance

Exclusion Criteria:

• Emergency surgery
• Approach by thoracotomy
• Heart transplant
• Aortic dissection or chirurgical act on ascending thoracic Aorta
• Redo surgery.
• Pregnant women
• Protected minors or adults
• Pre-existing psychiatric pathology including known states of opioid addiction
• Long-term opioid medication (>1month)
• Physical or intellectual inability to use a PCA
• Severe heart failure (ejection fraction less than 40% or PAH > 50 mmHg)
• Preoperative cardiogenic shock
• Severe preoperative chronic or acute renal failure with a creatinine clearance of less than 30 mL / min according to Cockroft's formula
• Known allergy or hypersensitivity to any of the study drugs or analgesia protocol (ropivacaine, paracetamol, opiates).
• Known allergy or hypersensitivity to any of excipients of the study drugs or analgesia protocol
• Refusal of the protocol

The patient will be under sedation during the block performance. Th nurse in charge to the patient will be absent during the block performance and the block will be realized by the practitioner who will not take care of the patient during his hospitalization