This study compares the analgesic effects and dermatomal blockade distributions of single and double injection bilateral thoracic paravertebral block (TPVB) techniques in patients undergoing reduction mammaplasty.

After obtaining ethics committee approval; 60 patients scheduled for elective bilateral reduction mammoplasty and gave written informed consent, were included in the study. The patients were randomized in one of single (Group S: T3-T4) or double injections (Group D: T2-T3&T4-T5) bilateral TPVB groups (bupivacaine 0.375% 20 mL per side). All patients' dermatomal blockade distributions (T2-T6) were followed for 30 minutes, and then they were given general anesthesia. Before extubation, 1 g IV paracetamol was applied to all. Postoperatively, patients in both groups received IV paracetamol 1 g when numeric rating scale (NRS) pain score ≥4, and also tramadol 1 mg/kg if they defined NRS≥4 again after 1 h. The primary endpoint was NRS pain scores at postoperative 12th hour. The secondary endpoints were NRS scores and dermatomal blockade distributions through the postoperative first 48 hours, postoperative time until first pain, the total numbers of analgesic requirements on days 1 and 2.

This prospective randomized controlled study compares the analgesic effects and dermatomal blockade distributions of single and double injection bilateral thoracic paravertebral block (TPVB) techniques in patients undergoing reduction mammaplasty.

After obtaining ethics committee approval; 60 patients scheduled for elective bilateral reduction mammoplasty and gave written informed consent, were included in the study. The inclusion criteria were female gender, aging between 18 and 70 years, American Society of Anesthesiologists (ASA) physical status of 1-3, capable of consenting, understanding the instructions for using the NRS pain scores and replying the study-based questions, lack of contraindications to regional anesthesia (allergy to a LA, local infection, and coagulopathy) and especially TPVB, absence of mental/psychiatric disorders, chronic analgesic/opioid use and alcohol/illicit drug use. The patients were randomized in one of single (Group S: T3-T4-bupivacaine 0.375% 20 mL/injection) or double injections (Group D: T2-T3&T4-T5-bupivacaine 0.375% 10 mL/injection) bilateral TPVB groups using the sealed envelopes technique. All patients' dermatomal (sensorial) blockade distributions (T2-T6) were tested bilaterally between T2 and T6 dermatomal levels on the midclavicular line in every 5 minutes through the first 30 minutes after TPVB performances, by using the pin-prick test, and then they were given standard general anesthesia. Before extubation, 1 g IV paracetamol was applied to all. The NRS pain scores (0: no pain and 10: worst pain imaginable), and the dermatomal blockade distribution/numbers of blocked dermatomes of all patients on both sides were asked and documented on postoperative 0th min, 1st, 2nd, 6th, 12th, 24th and 48th hours. Postoperatively, patients in both groups received IV paracetamol 1 g when NRS pain score ≥4, and also tramadol 1 mg/kg if they defined NRS≥4 again after 1 h. The primary endpoint was NRS pain score at 12th hour. The secondary endpoints included the NRS pain scores and the dermatomal blockade distribution/numbers of blocked dermatomes through the postoperative first 48 hours, block application times, number of patients experienced hypotension or required fentanyl intraoperatively, length of stay in postoperative care unit (PACU), postoperative time until first pain (NRS≥4), the total numbers of paracetamol and tramadol requirements, incidence of postoperative nausea and vomiting (PONV) and duration of sleep on postoperative days 1 and 2, patient and surgeon satisfaction scores.

Inclusion Criteria:

• American Society of Anesthesiologists (ASA) physical status of 1-3
• Capable of consenting
• Capable of understanding the instructions for using the NRS pain scores
• Capable of replying the study-based questions
• Lack of contraindications to regional anesthesia (allergy to a LA, local infection, and coagulopathy) and especially TPVB
• Absence of mental/psychiatric disorders
• Absence of chronic analgesic/opioid use
• Absence of alcohol/illicit drug use

Exclusion Criteria:

• Patient refusal
• American Society of Anesthesiologists (ASA) physical status of 4
• Not capable of consenting
• Not capable of understanding the instructions for using the NRS pain scores
• Not capable of replying the study-based questions
• Contraindications to regional anesthesia (allergy to a LA, local infection, and coagulopathy) and especially TPVB
• Presence of mental/psychiatric disorders
• Presence of chronic analgesic/opioid use
• Presence of alcohol/illicit drug use

• All TPVB procedures were performed by the same 3 senior anesthesiology residents, always under the supervision of 2 attending anesthesiologists (1 senior resident with 1 attending anesthesiologist at a time)
• Preoperatively, the anesthesiologists who were blinded to the group of that specific patient evaluated the sensorial blockade of dermatomes separately on both sides
• Postoperatively, different anesthesiologists who did not participate in the TPVB performance process of that specific patient and were totally blinded to the group again collected the data.
• Surgeons were also blinded.