Intercostal Nerve Cryoanalgesia vs BRILMA Block for Minithoracotomy on Cardiac Surgery

Patients undegoing cardiac surgery by minithoracotomy present severe acute postoperative pain. Cryoanalgesia of the intercostal nerves and BRILMA block are performed as techniques of postoperative analgesia of the chest wall, and can provide a solution for this postoperative pain. Both nerve block techniques could have similar effects on postoperative pain control during the first postoperative hours. However, cryoanalgesia of the intercostal nerves may provide a longer duration than that provided by BRILMA block.

Outcomes:

• Compare the postoperative analgesia provided by BRILMA block and intercostal nerve cryoanalgesia in patients undergoing cardiac surgery by minithoracotomy.
• Determine the percentage of patients with neuropathic pain at hospital discharge and 30 days after surgery.

Methods:

Prospective observational study using two analgesic techniques (BRILMA block vs intercostal nerve cryoanalgesia).

Inclusion criteria

patients > 18 years of age, underwent cardiac surgery by minithoracotomy Exclusion criteria: patients <18 years old, patients undergoing cardiac surgery by sternotomy, habitual consumption of analgesics, neurological diseases with deterioration of the level of consciousness and patients with previous neuropathic pain.

Technic: For BRILMA block, 0.4 ml/kg of 0.3% ropivacaine will be injected between the medial aspect of the serratus anterior muscle and the external intercostal muscle (thoraco-dentate space) covering 3 intercostal spaces (3rd, 4th and 5th). A catheter will be placed in the 4th intercostal space that will provide analgesia for the first three postoperative days. The cryoanalgesia technique will be performed by the surgeon before the closure of the minithoracotomy, on the right hemithorax. An external cryogenic system AtriCure CE0123 will be used for use with cryoICE AtriCure 10 cm Cryoablation Probe, CE2797. The cryoprobe will be applied on the lower costal ridge at the level of the 3rd, 4th and 5th intercostal spaces.

Postoperative pain (location and intensity) will be evaluated using a Simple Verbal Scale from 0 (no pain) to 10 (maximum imaginable pain). The need for rescue analgesia will be collected during hospital stay. At 24, 48 and 72 h after surgery and at hospital discharge, the maximum score of pain experienced by the patient (at rest and deep inspiration) will be collected. At hospital discharge, an investigator will evaluate the occurrence of neuropathic pain using the DN-4 scale (Douleur Neuropatique in 4 questions). In addition, the patient will complete these four questions 30 days after surgery and the results will be known by the responsible researcher

Inclusion criteria

• Patients > 18 years of age, underwent cardiac surgery by minithoracotomy
• Cardiac surgery
• Minithoracotomy

Exclusion criteria

• <18 years old
• Patients undergoing cardiac surgery by sternotomy
• Patients with regular consumption of analgesics,
• Patients with neurological diseases with altered level of consciousness
• Patients with previous neuropathic pain.