Erector spinae-plane block as an analgesic alternative in patients undergoing mitral and/or tricuspid valve repair through a right mini-thoracotomy – an observational cohort study

Introduction
One of the main challenges in cardiac surgery is effective postoperative analgesia. Erector spinae-plane block (ESP block) is a novel regional technique, introduced by Forero in 2016 for neuropathic chest pain, then used successfully for mastectomy.

Aim
To establish the efficacy of the ESP block in patients undergoing mitral and/or tricuspid valve repair through a right mini-thoracotomy.

Material and methods
It is a prospective observational cohort study performed in a tertiary health center. In the treatment group, a single-shot ESP block was performed before anesthetic induction. General anesthesia was induced with etomidate, remifentanil, and rocuronium, and continued with sevoflurane and remifentanil. Remifentanil infusion was continued for 2 h post-operatively, then stopped, and the patient’s trachea was extubated. Patient-controlled analgesia was started with oxycodone immediately. Total oxycodone consumption and pain severity on the visual analog scale during the first 24 h were analyzed. In the control group, no regional block was performed. Instead of remifentanil, fentanyl was used. Patients were extubated on the second day. Pain was treated with morphine, administered according to nurses’ discretion. Pain intensity was evaluated on the numerical rating scale.

Results
Nineteen patients were evaluated in the ESP and 25 in the control group. Mechanical ventilation time was shorter in the ESP group (0.6 (0.4–1.1) h) than in the control one (10 (8–17) h, p = 0.00001). Moreover, patients in the ESP group spent fewer days in the intensive care unit (1 (1–1) vs. (2 (2–2), p = 0.0001).

Conclusions
The ESP block seems to be safe and efficient for pain control in patients undergoing right mini-thoracotomy for mitral and/or tricuspid valve repair.