Transversus thoracis muscle plane block in cardiac surgery: a pilot feasibility study

Abstract

IntroductionCardiac surgery patients often experience significant pain after median sternotomy. The transversus thoracis muscle plane (TTP) block is a newly developed, single-shot nerve block technique that provides analgesia for the anterior chest wall. In this double-blind pilot study, we assessed the feasibility of performing this novel block as an analgesic adjunct.MethodsAll patients aged 18–90 undergoing elective cardiac surgery were randomized to the block or standard care control group on admission to the intensive care unit after surgery. Under ultrasound guidance, patients in the block group received the TTP block with 20 mL of either 0.3% or 0.5% ropivacaine bilaterally, based on weight. The control group did not receive any injections. All blocks were performed by a single anesthesiologist, and data collection was performed by blinded assessors. The primary feasibility outcomes were rate of recruitment, adherence, and adverse events. The rate of recruitment was defined as the ratio of patients giving informed consent to the number of eligible patients who were approached to participate. Secondary outcomes included 12-hour and 24-hour Numeric Rating Scale (NRS) pain scores, 24-hour hydromorphone and acetaminophen requirements, time to extubation, time to first opioid administration, and patient satisfaction (on a yes/no questionnaire) at 24 hours.ResultsTwenty patients were approached for this study and 19 were enrolled. Eight patients received the intended intervention in each group. The recruitment rate was 95% of all approached eligible patients, and the adherence rate to treatment group was 94%. There were no block-related adverse events. The mean (SD) NRS pain scores at rest were 3.3 (3.2) in the block group vs 5.6 (3.2) in the control group at 12 hours. At 24 hours, the pain scores were 4.1 (3.9) vs 4.1 (3.3) in the block and control group, respectively. The mean (SD) 24-hour hydromorphone administration was 1.9 (1.1) mg in the block group vs 1.8 (0.9) mg in the control group.DiscussionThe TTP block is a novel pain management strategy poststernotomy. The results reveal a high patient recruitment, adherence, and satisfaction rate, and provide some preliminary data supporting safety.Trial registration number NCT03128346.

Pain relief following sternotomy in conventional cardiac surgery: A review of non neuraxial regional nerve blocks

“…The results revealed a high patient recruitment, adherence, and satisfaction rate. [ 37 ] A possible limitation of TTP block may be disruption of the plane during internal mammary artery (IMA) harvesting (because the IMA courses in this plane) leading to non-spread of injectate between the desired thoracic levels. [ 38 ] Although known by different nomenclature, many of the above-mentioned blocks actually aim at anesthetizing anterior cutaneous branches.…”

Transversus Thoracis Muscle Plane Block

“…When we conducted our feasibility study for TTP block administration in the cardiac surgery intensive care unit [27], none of the 9 patients who underwent cardiac surgery and received the TTP block experienced a block related complication. Further studies with larger sample sizes are warranted to investigate the rate of these rare complications.…”

Transversus thoracis muscle plane block and parasternal block

“…Overall, some alternative techniques to TTP block have been increasingly reported1 3 4; however, TTP block has the most robust evidence5 based on randomized clinical trials so far. Once future clinical trials confirm the superiority of PS block over TTP block, it will bring us one more step closer to the routine application of regional technique in cardiac surgery.…”