Bilateral Thoracic Paravertebral Blocks in Obese and Non-obese Patients Undergoing Reduction Mammaplasty

Aim: The number of obese patients (body mass index (BMI)≥30) has increased dramatically worldwide, and we, as anesthesiologists, routinely come up against them in our daily clinical practice. Although the preference of various peripheral and neuroaxial regional anesthesia (RA) techniques seems to be advantageous in the anesthetic management of these patients, their performances can also be associated with technical difficulties and greater failure rates. The aim of this study is to compare the performance properties and analgesic efficacy of ultrasound (US)-guided thoracic paravertebral blocks (TPVBs) in obese and non-obese patients.

Material methods: After obtaining ethics committee approval; data of 82 patients, who underwent elective bilateral reduction mammaplasty under general anesthesia with adjunctive TPVB analgesia between December of 2016 and February of 2020, were reviewed. Patients were allocated into two groups with respect to their BMI scores (Group NO: BMI<30 and Group O: BMI≥30). Demographics, TPVB ideal US image visualization and performance times, needle tip visualisation and TPVB performance difficulties, number of needle maneuvers, surgical, anesthetic and analgesic follow-up parameters, incidence of postoperative nausea vomiting (PONV), sleep duration, length of postanesthesia care unit (PACU) and hospital stay, patient and surgeon satisfaction scores were all investigated and compared. Student's t, Mann-Whitney-U and Chi-square tests were used for statistical analysis.

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 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 of RA/TPVB performance
• 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 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