ASRA Pain Medicine Update

Fast-track cardiac surgery typically refers to the use of patient care protocols intended to hasten postoperative extubation and mobilization. Literature suggests that enhanced recovery and fast-track cardiac surgery pathways appear to demonstrate improved outcomes without compromising patient safety.^[1] Their benefits include shorter intensive care unit stays, reduced duration of mechanical ventilation, and lower health care costs.^[1],[2] Regional anesthesia has played an important role in enhanced recovery pathways for other surgical services and allows for reduced systemic opioid use during intraoperative and postoperative care.

Until now, the role of regional anesthesia has remained somewhat limited in cardiac surgery because of safety concerns inherent in using paravertebral and neuraxial techniques with anticoagulated patients.^[3] However, with the recent development of the erector spinae plane (ESP) block, regional anesthesia may be able to be safely integrated into enhanced recovery pathways for cardiac surgery patients.

We have successfully and safely used ESP blocks and other regional anesthesia techniques to reduce intraoperative and postoperative opiate use and to facilitate fast-track extubation in select adult and pediatric cardiothoracic surgery patients.

An ESP block is performed by depositing local anesthetic deep to the erector spinae muscles and superficial to the transverse processes. The block is typically completed under ultrasound guidance and can be performed in cervical, thoracic, or lumbar levels for a wide variety of surgical or chronic pain indications, including cardiothoracic surgery.^[4] ESP blocks avoid the epidural venous plexus, which should minimize risk of an epidural hematoma in coagulopathic patients. Anatomically, the transverse process is easily visible in most patients with ultrasound and provides an inferior border that should reduce the risk of pneumothorax when compared with the paravertebral block. As an interfascial plane block, local anesthetic spread is dependent on the volume injected—selected with caution, especially for patients with low cardiac output.

Cadaveric studies of thoracic ESP blocks show that spread often includes levels T2–T6 and, as such, could be expected to anesthetize a mid-sternotomy incision.^[5] The limitations of cadaveric studies aside, the spread of local anesthetic anteriorly to the paravertebral space often appears limited despite proximity of the injection site to the costotransverse foramen, suggesting a mechanism of action at the lateral cutaneous branches of the intercostal nerves.^[5],[6] Limited data in patients undergoing magnetic resonance imaging have also demonstrated transforaminal paravertebral and even circumferential epidural spread, suggesting that cadaveric data may not fully capture the spread in vivo.^[7]

Numerous case reports suggest ESP blocks’ potential usefulness in cardiac surgery. Presently, the largest randomized controlled trial (RCT) of 106 adult cardiac surgery patients compares ESP blocks with paracetamol and tramadol. The researchers found that median pain scores at rest were lower after extubation in the ESP group, which also had a longer mean duration of analgesia.^[8] A separate RCT comparing ESP with thoracic epidurals found that pain scores appeared similar between the two groups postoperatively, with lower scores noted in the ESP group from 24–48 hours postoperatively.^[9] In a case report from our institution, an ESP block was used to facilitate immediate extubation following opioid-free coronary artery bypass grafting.^[10]

Indeed, we have successfully and safely used ESP blocks and other regional anesthesia techniques to reduce intraoperative and postoperative opiate use and to facilitate fast-track extubation in select adult and pediatric cardiothoracic surgery patients. Although more studies are needed to elucidate the block’s merits for this indication, our experiences thus far have been encouraging, and a large, multicenter study is underway.

Members of the multidisciplinary RACER group at Lucile Packard Children’s Hospital at Stanford University. Left to right: Carole Lin, MD (pediatric anesthesia), May Wu, PharmD (pharmacy), David Kwiatkowski, MD (cardiac ICU), Katsuhide Maeda, MD (cardiothoracic surgery), Ban Tsui, MD, FRCP(C) (pediatric anesthesia), Gail Boltz, MD (cardiac anesthesia), Tom Caruso, MD (pediatric anesthesia), and Curtis Darling, MD (pediatric anesthesia).

Implementation of the new pathways necessitated the formation of an institutional regional anesthesia cardiothoracic enhanced recovery (RACER) group: a multidisciplinary team including cardiac and regional anesthesiologists, cardiac surgeons, pain physicians, intensivists, pharmacists, and advanced practice providers who are motivated to improve patient care and safety. The team works together to ensure that the entire cardiac surgery process, from patient identification for fast-track candidacy to discharge home, is as streamlined as possible. Truly, the implementation and research of these newly developed techniques and protocols heavily depend on combined team efforts.

We are also excited to announce that ASRA recently approved a RACER special interest group (SIG), reflecting the momentum that regional anesthesia is building in cardiothoracic surgery. Use of regional anesthesia in this high-risk patient population has the potential to radically transform management and improve outcomes.

The vision for the RACER SIG is to establish a benchmark of regional anesthesia best practices for cardiothoracic benefit, using the latest science and technology worldwide. The SIG’s mission is to aid pain physicians in providing safe and effective regional anesthesia and analgesia to all eligible cardiothoracic surgery patients through excellence in research, education, and clinical care in cardiac and regional anesthesia. More specifically, the RACER SIG’s goals are to (1) promote safe, effective, and efficient application of regional anesthesia in cardiothoracic surgery; (2) raise awareness and educate regional and cardiac anesthesiologists on the impact of regional anesthesia on recovery after cardiac surgery; (3) advance our own knowledge of novel regional anesthesia techniques in the perioperative setting; and (4) encourage a multidisciplinary approach to regional anesthesia as we work alongside surgeons, intensivists, cardiothoracic anesthesiologists, and other members of the care team. At national conferences, the RACER SIG will present topics and outcome studies related to the use of regional techniques to enhance recovery after cardiac surgery, including postoperative length of stay, time to extubation, chest tube duration, systemic inflammation multiorgan protection, and postoperative opioid consumption.

We hope you will consider joining the new RACER SIG and, together, we look forward to advancing the field of cardiothoracic regional anesthesia.

References

1. Wong WT, Lai VK, Chee YE, Lee A. Fast-track cardiac care for adult cardiac surgical patients. Cochrane Database Syst Rev. 2016;9:CD003587. https://doi.org/10.1002/14651858.CD003587.pub3
2. Gimpel D, Shanbhag S, Srivastava T, et al. Early discharge from intensive care after cardiac surgery is feasible with an adequate fast track, stepdown unit: Waikato experience. Heart Lung Circ. 2018. https://doi.org/10.1016/j.hlc.2018.11.002
3. Chaney, MA. Intrathecal and epidural anesthesia and analgesia for cardiac surgery. Anesth Analg. 2006;102(1):45–64. https://doi.org/10.1213/01.ane.0000183650.16038.f6
4. Tsui BCH, Fonseca A, Munshey F, et al. The erector spinae plane (ESP) block: a pooled review of 242 cases. J Clin Anesth. 2018;53:29–34. https://doi.org/10.1016/j.jclinane.2018.09.036
5. Yang HM, Choi YJ, Kwon HJ, et al. Comparison of injectate spread and nerve involvement between retrolaminar and erector spinae plane blocks in the thoracic region: a cadaveric study. Anaesthesia. 2018;73(10):1244–1250. https://doi.org/10.1111/anae.14408
6. Ivanusic J, Konishi Y, Barrington MJ. A cadaveric study investigating the mechanism of action of erector spinae blockade. Reg Anesth Pain Med. 2018;43(6):567–571. https://doi.org/10.1097/AAP.0000000000000789
7. Schwartzmann A, Peng P, Maciel MA, Forero M. Mechanism of the erector spinae plane block: insights from a magnetic resonance imaging study. Can J Anaesth. 2018;65(10):1165–1166. https://doi.org/10.1007/s12630-018-1187-y
8. Krishna SN, Chauhan S, Bhoi D, et al. Bilateral erector spinae plane block for acute post-surgical pain in adult cardiac surgical patients: a randomized controlled trial. J Cardiothorac Vasc Anesth. 2019;33(2):368–375. https://doi.org/10.1053/j.jvca.2018.05.050
9. Nagaraja PS, Ragavendran S, Singh NG, et al. Comparison of continuous thoracic epidural analgesia with bilateral erector spinae plane block for perioperative pain management in cardiac surgery. Ann Card Anaesth. 2018;21(3):323–327. https://doi.org/10.4103/aca.ACA_16_18
10. Chanowski EJP, Horn JL, Boyd JH, et al. Opioid-free ultra-fast-track on-pump coronary artery bypass grafting using erector spinae plane catheters. J Cardiothorac Vasc Anesth. 2018. https://doi.org/10.1053/j.jvca.2018.10.012