To Compare the Efficacy of Sub-Pecto-Interfascial Block with Erector Spinae Plane Block in Postoperative Pain Management in Patients Undergoing Cardiac Surgery

Abstract

Pain following sternotomy has always been an issue of major concern for anesthesiologists. The incidence of pain is as high as 49% at rest following coronary artery bypass grafting. We planned to utilize the sub-pecto-interfascial plane (SIP) block and erector spinae plane (ESP) block to determine its efficacy and quality of analgesia as compared to conventional intravenous analgesia. After the Institutional Ethics Committee’s approval, we recruited 105 patients and randomized them into three groups. Group 1 received conventional analgesia, group 2 SIP, and group 3 ESP block. Group 2 and Group 3 received allocated blocks after induction of balanced general anesthesia under ultrasound guidance. With high-frequency linear probe (13 MHz) planes identified, a mixture of injection ropivacaine (0.375%) and dexmedetomidine (1.1 mcg/mL) was deposited. In group 2, six injections of 6 mL each at the 2nd, 4th, and 6th intercostal spaces in the bilateral parasternal region. In group 3, two injections of 20 mL of the above-mentioned mixture on each side above the transverse process of the T5 vertebra under the erector spinae muscle plane were injected. All patients were monitored throughout the procedures, and their vitals were recorded. Heart rate, systolic blood pressure, and diastolic blood pressure were noted at baseline, at skin incision, at sternotomy, and 30 min post-extubation. Patients were followed for total fentanyl consumption, pain score (numerical rating scale [NRS] score), and peak inspiratory flow rate, which were noted at extubation and 2, 4, 6, 8, 12, and 24 hours post-extubation. Levels of C-reactive protein (CRP), cortisol, and prolactin were done at baseline and 24 h after surgery. Extubation time, time of first oral intake, and total length of intensive care unit (ICU) stay were also compared between the groups. Total fentanyl consumption was significantly lower (P < 0.005) in group 2 and group 3 compared to group 1. Patient receiving blocks were significantly lower NRS score compared to the control group. Spirometry has shown improved results in block groups catering to early discharge from ICU. Rise in levels of CRP, cortisol, and prolactin were much higher in group 1 as compared to group 2 and group 3. The application of ESP and SIP blocks is far superior than conventional parenteral analgesics in terms of pain score, total opioid’s consumption, hemodynamic maintenance, spirometry efforts, and length of ICU stays.