Analgesic efficacy of ultrasound guided bilateral transversus thoracis muscle plane block in pediatric cardiac surgery: a randomized, double-blind, controlled study and Preoperative Implementation of Transverse Thoracic Muscle Plane Block and Rectus Sheath Block Combination for Pediatric Cardiac Surgery.
These two single centre studies investigated the effect of Transversus/Transverse Thoracis/Thoracic Muscle Plane (TTMP) blocks, placed pre-incision in cardiac cases done via sternotomy, on post-operative opioid consumption. The rationale for adding the Rectus Sheath Block (RSB) in the second paper was to relieve pain associated with the chest drains.
TTM plane blocks provide sensory cover for the 2nd to 6th intercostal nerves and are performed bilaterally, depositing local anaesthetic in the plane between the internal intercostal and transversus thoracis muscles lying superficially to the pleura. The RSB is performed by placing local anaesthetic between the rectus abdominis muscle and the posterior rectus sheath. A detailed description of the performance of each procedure, together with ultrasound images, is provided in the paper by Yamamoto et al.
The motivation for each paper stemmed from the desire to facilitate a reduction in intra- and post-operative opioid use, facilitate early extubation and reduce ICU length of stay, while avoiding the risks associated with neuraxial procedures and the full heparinization required for cardiopulmonary bypass.
The results and experiences respectively demonstrated statistically significant benefits in terms of reduced fentanyl administration in the groups receiving a TTMP block. Abdelbaser & Mageed used a control group (Normal Saline injected) to compare the effects of the TTM plane block whereas Yamamoto et al provide a description of their procedures and experiences only. Time to first rescue analgesia, time to extubation and ICU length of stay in the first paper was reduced by 4hrs, 3hrs & 6hrs respectively which were all statistically significant but may not necessarily translate into clinical significance in terms of a reduction in time.
Both groups of authors conclude that the TTMP technique is effective in reducing intra- and post-operative fentanyl requirements facilitating fast-tracked extubation, are easy to perform using ultrasound and have a low risk of complications with no evidence of any pneumothorax, haematoma development, infection or local anaesthetic toxicity reported.
Reviewed by Neil Hauser
Abdelbaser II, Mageed NA. Analgesic efficacy of ultrasound guided bilateral transversus thoracis muscle plane block in pediatric cardiac surgery: a randomized, double-blind, controlled study. J Clin Anesth. 2020;67:110002. doi:10.1016/j.jclinane.2020.110002
Yamamoto T, Seino Y, Matsuda K, et al. Preoperative Implementation of Transverse Thoracic Muscle Plane Block and Rectus Sheath Block Combination for Pediatric Cardiac Surgery. J Cardiothorac Vasc Anesth. 2020;34(12):3367-3372. doi:10.1053/j.jvca.2020.07.041