Comparison of Effectiveness of Erector Spinae Plane Block and Thoracal Paravertebral Block for Postoperative Analgesia After Cardiovascular Surgery: Randomized Study

Pain is a common and serious problem after cardiovascular surgery. It is associated with increased morbidity and mortality, and additional risk factors of cardiac surgery such as sternotomy and cardiopulmonary bypass contribute to this. Patient-controlled analgesia with intravenous opioids is standard in many centers for the management of pain after cardiac surgery. However, intravenous opioids have a higher risk of nausea and vomiting and may delay weaning from mechanical ventilation compared to regional techniques. Elderly patients have a higher risk of opioid-related complications, and regional techniques can help reduce postoperative ventilation time and accelerate postoperative recovery, which will reduce the risk of atelectasis, especially in the elderly population. Thoracic paravertebral block (TPVB) is difficult to apply due to its anatomical proximity to important structures such as the pleura and central neuraxial system, and may cause complications such as pneumothorax and vascular injury. Analgesia management is very important in these patients, since insufficient analgesia may cause pulmonary complications such as atelectasis, pneumonia, and increased oxygen consumption in the postoperative period.

Erector spina plane (ESP) block performed with ultrasound (US) is a new interfacial plane block defined by Forero et al. in 2016. If the ESP block is applied at the T5 level, it provides thoracic analgesia, if it is applied at the T7-9 level, it provides analgesia in the abdominal region. This block is applied by injecting a solution containing local anesthetic into the fascia under the erector spina muscle. Since the application site of the ESP block is far from the pleura and neuraxial tissues, it minimizes the risk of complications due to injury to these structures. Sonoanatomy is easy to visualize on US and the spread of local anesthetic can be seen easily. With the cephalo-caudal spread of the local anesthetic solution, analgesia occurs in several dermatomes. Cadaveric studies have shown that the injection spreads to the ventral and dorsal roots of the spinal nerves and creates sensory blockade in both the anterolateral thorax and the posterior. In the literature, it has been reported that it provides effective analgesia in randomized controlled studies investigating the effectiveness of ESP block for postoperative analgesia management after open heart surgery, breast surgery and ventral hernia repair.

In this study, it is aimed to compare the effectiveness of US-guided ESP block and TPVB for postoperative analgesia management after cardiovascular surgery. Our primary aim is to compare postoperative pain scores (NRS), and our secondary aim is to evaluate rescue analgesia using, opioid-related side effects (allergic reaction, nausea, vomiting) and complications that may occur due to block (pneumothorax, hematoma).