Single and Double Injection Bilateral Thoracic Paravertebral Blocks in Reduction Mammaplasty

Study Overview
=================
Brief Summary
-----------------
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.

Detailed Description
-----------------
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.

Official Title
-----------------
Comparison of Single and Double Injection Ultrasound-Guided Bilateral Thoracic Paravertebral Block Effects in Patients Undergoing Reduction Mammaplasty: A Prospective Randomized Controlled Study

Conditions
-----------------
Pain, Postoperative

Intervention / Treatment
-----------------
* Procedure: Thoracic paravertebral block-single injection
* Procedure: Thoracic paravertebral block-double injection


Participation Criteria
=================
Eligibility Criteria
-----------------
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

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 70 Years

Sexes Eligible for Study
-----------------
Female

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Supportive Care
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Patients undergoing reduction mammaplasty, received single or double injection bilateral thoracic paravertebral block (TPVB) for postoperative analgesia
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Group S (single injection TPVB group)<br>Patients received bilateral single injection ultrasound-guided TPVB at the level of T3-T4 with 20 mL bupivacaine 0.375% per injection/side. | Procedure: Thoracic paravertebral block-single injection<br>* The blocks were performed at the T3-T4 level bilaterally to block the dermatomes between the T2 and T6 levels (breast innervation area).<br>|
| Active Comparator: Group D (double injection TPVB group)<br>Patients received bilateral double injection ultrasound-guided TPVB at the level of T2-T3 and T4-T5 with 10 mL bupivacaine 0.375% per injection (20 mL bupivacaine 0.375% per side as the single injection group). | Procedure: Thoracic paravertebral block-double injection<br>* The blocks were performed at both T2-T3 and T4-T5 levels bilaterally to block the dermatomes between the T2 and T6 levels (breast innervation area).<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pain (Numeric rating scale (NRS)) score | NRS pain score (0: no pain, 10: worst pain imaginable) on postoperative 12th hour | 12th hour | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pain (Numeric rating scale (NRS)) score | NRS pain scores (0: no pain, 10: worst pain imaginable) on postoperative 0th min, 1st, 2nd, 6th, 24th and 48th hours on both sides | 0-48 hours | 
| Dermatomal blockade distribution/numbers of blocked dermatomes | Preoperatively, the sensorial blockade was tested bilaterally between the T2 and T6 dermatomal levels (4 regions) on the midclavicular line of the patients in every 5 min through the first 30 min after TPVB performances, by using the pin-prick test. Sensations: normal, decreased sensation or total anesthesia separately on both sides. The answers such as decreased sensation or total anesthesia in different dermatomal regions within T2-T6 were accepted as successfully blocked dermatome, and the numbers of blocked dermatomes out of 4 dermatomal regions were noted for the right and the left sides. | 0-30 minutes | 
| Dermatomal blockade distribution/numbers of blocked dermatomes | Postoperatively, the sensorial blockade was tested bilaterally between the T2 and T6 dermatomal levels (4 regions) on the midclavicular line of the patients on postoperative 0th min, 1st, 2nd, 6th, 12th, 24th and 48th hours, by using the pin-prick test. Sensations: normal, decreased sensation or total anesthesia separately on both sides. The answers such as decreased sensation or total anesthesia in different dermatomal regions within T2-T6 were accepted as successfully blocked dermatome, and the numbers of blocked dermatomes out of 4 dermatomal regions were noted for the right and the left sides. | 0-48 hours | 
| Block application time | The bilateral TPVB application time was defined as the time period between the needle insertion at the first determined level and the needle withdrawal from the last determined level. | 2-20 minutes | 
| Number of patients experienced hypotension intraoperatively | The mean arterial pressure (MAP) decreased >20% below preinduction value | Intraoperative 2-4 hours | 
| Number of patients required fentanyl intraoperatively | If a ≥ 20% increase above preinduction values in MAP or HR was observed during the perioperative period, additional fentanyl dose (1 µg/kg) was applied intravenously. | Intraoperative 2-4 hours | 
| Length of stay in postoanesthesia care unit (PACU) | Discharge from PACU was determined using the White Fast tracking score ≥12, whereas none of the parameters was <1 in any category | 0-1 hours | 
| Postoperative time until first pain | Postoperative first pain description (NRS ≥4) | 0-48 hours | 
| Paracetamol consumption/the total numbers of paracetamol requirements | Paracetamol was used when postoperative pain NRS ≥4 in the postanesthesia care unit or on the wards (on postoperative days 1 and 2) | 0-48 hours | 
| Tramadol consumption/the total numbers of tramadol requirements | Tramadol was used when postoperative pain NRS ≥4 again after 1 h of paracetamol application in the postanesthesia care unit or on the wards (on postoperative days 1 and 2) | 0-48 hours | 
| Incidence of postoperative nausea and vomiting (PONV) | Number of feeling nausea or vomiting (on postoperative days 1 and 2) | 0-48 hours | 
| Duration of sleep | Total hours of sleep per day (on postoperative days 1 and 2) | 0-48 hours | 
| Patient satisfaction | Satisfaction score: 0: very unsatisfied, 3: very satisfied | 0-48 hours | 
| Surgeon satisfaction | Satisfaction score: 0: very unsatisfied, 3: very satisfied | 0-48 hours | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Thoracic paravertebral blocks, Postoperative analgesia, numeric rating scale, Dermatomal blockade distribution, Postoperative time until first pain, Analgesic consumption, Reduction mammaplasty