A randomised controlled trial of pectoral nerve-2 (PECS 2) block vs. serratus plane block for chronic pain after mastectomy

Thoracic interfascial plane blocks are effective for post-mastectomy acute analgesia. However, their effects on chronic pain are uncertain. We randomly allocated 80 women equally to pectoral nerve-2 (PECS 2) block or serratus plane block. The pectoral nerve-2 block reduced the rate of moderate or severe chronic pain from 13/40 (33%) with the serratus plane block to 4/40 (10%), p = 0.03, adjusted odds ratio (95%CI) 0.23 (0.07–0.80), p = 0.02. The rates of pain-free women at six postoperative months were indeterminate, 10/40 (25%) after serratus plane block vs. 19/40 (48%) after pectoral nerve-2 block, p = 0.06, adjusted odds ratio (95%CI) 2.9 (1.1–7.5), p = 0.03. Health-related quality of life at six postoperative months was similar after serratus plane and pectoral nerve-2 blocks, mean (SD) EQ-5D-3L scores 0.87 (0.15) vs. 0.91 (0.14), respectively, p = 0.21. The pectoral nerve-2 block reduced median (IQR [range]) morphine consumption in the first 24 postoperative hours from 6 (3–9 [1–25]) mg to 4 (2–7 [0–37]) mg, p = 0.04. However, acute pain scores after serratus plane and pectoral nerve-2 blocks were similar, median (IQR [range]) 23 (11–35 [0–70]) mm vs. 18 (11–27 [0–61]) mm, respectively, p = 0.44. Pectoral nerve-2 block reduced chronic pain 6 months after mastectomy compared with serratus plane block.     

Adrenaline markedly improves thoracic epidural analgesia produced by a low-dose infusion of bupivacaine, fentanyl and adrenaline after major surgery: A randomised, double-blind, cross-over study with and without adrenaline

Background: Basic pharmacological research indicates that there are synergistic antinociceptive effects at the spinal cord level between adrenaline, fentanyl and bupivacaine. Our clinical experience with such a mixture in a thoracic epidural infusion after major surgery confirms this. The objectives of the present study were to evaluate the effects on postoperative pain intensity, pain relief and side effects when removing adrenaline from this triple epidural mixture. Methods: A prospective, randomised, double-blind, cross-over study was carried out in 24 patients after major thoracic or abdominal surgery. Patients with only mild pain when coughing during a titrated thoracic epidural infusion of about 10 ml · h^?1 of bupivacaine 1 mg · ml^?1, fentanyl 2 μg · ml^?1, and adrenaline 2 μg · ml^?1 were included. On the 1^st and 2^nd postoperative days each patient was given a double-blind epidural infusion, at the same rate, with or without adrenaline. The effect was observed for 4 h or until pain when coughing became unacceptable in spite of a rescue analgesic procedure. Rescue analgesia consisted of up to two epidural bolus injections per hour and i.v. morphine if necessary. All patients received rectal paracetamol 1 g, every 8 h. Fentanyl serum concentrations were measured with a radioimmunoassay technique at the start and end of each study period. Main outcome measures were extent of sensory blockade and pain intensity at rest and when coughing, evaluated by a visual analogue scale, a verbal categorical rating scale, the Prince Henry Hospital pain score, and an overall quality of pain relief score. Results: The number of hypaesthetic dermatomal segments decreased (P <0.001) and pain intensity at rest and when coughing increased (P <0.001) when adrenaline was omitted from the triple epidural mixture. This change started within the first hour after removing adrenaline. After 3 h pain intensity when coughing had increased to unacceptable levels in spite of rescue analgesia (epidural bolus injections and i.v. morphine). Within 15–20 min after restarting the triple epidural mixture with adrenaline, pain intensity was again reduced to mild pain when coughing. Serum concentration of fentanyl doubled from 0.22 to 0.45 ng · ml^?1 (P <0.01), and there was more sedation during the period without adrenaline. Conclusions: Adrenaline increases sensory block and improves the pain-relieving effect of a mixture of bupivacaine and fentanyl infused epidurally at a thoracic level after major thoracic or abdominal surgery. Serum fentanyl concentrations doubled and sedation increased when adrenaline was removed from the epidural infusion, indicating more rapid vascular absorption and systemic effects of fentanyl.