Thoracic Paravertebral Block Superior to Erector Spinae Plane Block for Acute Pain Control After Mastectomy

A randomized controlled trial has found that ultrasound-guided thoracic paravertebral block (TPV) and erector spinae plane block (ESP) significantly reduce acute postoperative pain and opioid consumption in patients undergoing modified radical mastectomy, with TPV demonstrating superior efficacy in several measures.

The study, conducted at the South Egypt Cancer Institute, enrolled 105 women aged 20 to 70 who were undergoing unilateral mastectomy. Patients were randomized into three equal groups: one received general anesthesia combined with ESP, another received general anesthesia with TPV, and the third group received general anesthesia without any regional block.

The primary endpoint of the study was total morphine consumption within the first 24 hours after surgery. Patients in the TPV group required an average of 5.70 ± 1.95 mg of morphine, while those in the ESP group required 8.17 ± 1.69 mg. The control group had the highest morphine requirement at 10.74 ± 1.37 mg. The difference between the groups was statistically significant (P < .001), with TPV showing a significantly greater reduction in morphine use compared to ESP. The time to first analgesic request was also longest in the TPV group at 10.64 ± 1.83 hours, compared with 8.13 ± 1.75 hours in the ESP group and 4.37 ± 3.06 hours in the control group (P < .001).

Secondary outcomes included postoperative pain scores measured by the Visual Analogue Scale (VAS), serum levels of cortisol and prolactin as indicators of surgical stress, sedation scores, patient satisfaction, and incidence of opioid-related side effects. VAS scores at rest and during movement were significantly lower in the ESP and TPV groups compared with the control group (P < .001). TPV produced lower VAS scores than ESP during movement at the 12- and 24-hour postoperative marks. Cortisol and prolactin levels were significantly reduced in both block groups compared to control at all measured time points (P < .001), with no significant differences between ESP and TPV. Mean arterial pressure and heart rate were also lower in the TPV and ESP groups compared with control throughout the perioperative period. Sedation levels and patient satisfaction scores were higher in the ESP and TPV groups. The incidence of postoperative nausea, vomiting, and itching was lower in both block groups, with the control group experiencing more side effects.

The study was limited by its single-center design and lack of sensory mapping to define the dermatomal spread of each block. Additionally, the investigator performing the blocks was not blinded to group assignment, and single-injection techniques were used instead of continuous catheter-based analgesia.

The study authors concluded that both TPV and ESP blocks provided better early postoperative pain control and reduced the physiological stress response compared to general anesthesia alone. TPV was found to be more effective than ESP in managing acute postoperative pain, as indicated by lower morphine consumption, lower VAS scores, and a longer duration before the first request for additional analgesia. Both blocks were associated with reduced opioid-related side effects and improved long-term outcomes.

Reference:
Amr SA, Othman AH, Ahmed EH, Naeem RG, Kamal SM. Comparison between ultrasound guided erector spinae plane block and paravertebral block on acute and chronic post mastectomy pain after modified radical mastectomy: randomized controlled trial. BMC Anesthesiol. 2024;24(1):420. Published 2024 Nov 21. doi:10.1186/s12871-024-02810-4