INTRODUCTION
Cardiovascular diseases are prevalent in the general population globally and affect most of the older adult population. With the increase in longevity in recent years, there has been a considerable increase in surgical procedures related to cardiovascular diseases.1 The Society for Enhanced Recovery after Cardiac Surgery (ERASĀ® Cardiac) recommends effective perioperative pain control to improve patient outcomes. The goals of pain management are to alleviate suffering, gain early mobilization after surgery, reduce hospital stay, and improve patient satisfaction and functional recovery.2
The pain was most intense during the first two days after cardiac surgery and subsequently decreased. Inadequate acute postoperative pain control after cardiac surgery may result in chronic pain, which affects the quality of life. Seventeen percent of patients report chronic pain one year after cardiac surgery.3 Inadequate acute postoperative pain control can also increase pulmonary complications due to the inability to breathe, cough, and clear secretions.4 The leading causes of pain in cardiac surgery procedures are sternotomy/thoracotomy incisions, chest retraction, internal mammary artery harvesting, chest tubes, sternal wires, and visceral pain.5 Sternal pain is transmitted by the intercostal nerves raised from the T2-T6 spinal nerve roots.6 The mechanism of cardiovascular surgical pain can be represented as neuropathic and somatic pain, as it is commonly identical to postoperative pain.
The use of multimodal perioperative pain management strategies in current anesthesia practices is recommended instead of systemic analgesics or opioids only. In addition to pharmacological therapies, regional anesthesia (RA) interventions should be considered for every patient. The limited use of neuraxial procedures or paravertebral block in cardiac surgery with potential hemodynamic instability, full heparinization, and hemodilution is challenging for anesthesiologists.7 Chest wall fascial plane blocks are increasingly used to provide postoperative pain relief and decrease opioid consumption in patients undergoing cardiac surgery and show good results with fewer side effects when compared to central blocks, such as thoracic epidural analgesia or systemic analgesia, considering patients at high cardiovascular risk. In recent years, the development of new RA techniques, due to the role of ultrasonography, has enabled several new fascial plane blocks.8 Fascial plane blocks are often technically more accessible and less invasive than neuraxial analgesia for cardiac surgery. Several randomized controlled trials have compared the associations between regional anesthesia techniques and postoperative opioid consumption, pain scores, and complications, but the results are inconsistent for cardiac surgery.9 In addition, there are not enough studies comparing the effects of different fascial plane blocks in this subset of patients; hence, it would be of relevance to examine this aspect.
We hypothesized that the use of single-shot RA techniques would be associated with superior pain control and reductions in 24-h postoperative opioid consumption compared with placebo or systemic analgesics alone. This systematic review and network meta-analysis (NMA) aimed to compare the effects of single-shot ultrasound-guided RA techniques on open cardiac surgery.