Breast Neoplasm Female, Postoperative Pain Management
Conditions
Keywords
Anesthesia, Conduction, Mastectomy, Modified Radical, Breast Neoplasms, Postoperative Pain, Analgesia, Opioid, Nerve Block
Brief summary
This randomized controlled study aims to compare the analgesic efficacy of the ultrasound-guided modified pectoral nerve block (PECS II) and the midpoint transverse process to pleura (MTP) block in female patients undergoing modified radical mastectomy (MRM). Postoperative pain intensity will be assessed using the Visual Analog Scale (VAS) over the first 24 hours, with additional evaluation of opioid consumption and complications.
Detailed description
Modified radical mastectomy (MRM) is associated with significant postoperative pain, which may increase opioid use, delay recovery, and contribute to chronic post-mastectomy pain syndrome. This study compares two regional analgesic techniques: the ultrasound-guided modified pectoral nerve block (PECS II) and the midpoint transverse process to pleura (MTP) block. The PECS II block involves the injection of local anesthetic between the pectoralis minor and serratus anterior muscles, targeting the pectoral nerves and lateral cutaneous branches of intercostal nerves (T2-T6). It is widely used for anterior chest wall analgesia after breast surgery. The MTP block, a more recent paravertebral-domain technique, deposits anesthetic midway between the transverse process and the pleura, allowing spread to dorsal and ventral rami via the superior costotransverse ligament and potentially achieving broader thoracic segment coverage. This randomized trial evaluates postoperative pain control using the Visual Analog Scale (VAS) over 24 hours, along with opioid consumption and adverse events. The aim is to determine whether the MTP block offers superior analgesia and an opioid-sparing effect compared to the PECS II block.
Interventions
PROCEDUREPECS II BLOCK
In the supine position, as described by Blanco et al., the ultrasound probe was placed transversely beneath the clavicle. After identifying the intermuscular plane between the pectoralis major and minor, 10 mL of 0.25% bupivacaine was injected. The probe was then repositioned laterally to identify the plane between the pectoralis minor and serratus anterior at the third to fourth ribs, where a further 10 mL of 0.25% bupivacaine was injected.
PROCEDUREMTP BLOCK
The block was performed with the patient in a seated position. The ultrasound probe was positioned parasagittally, approximately 3 cm lateral to the midline, at the T2 and T6 vertebral levels. A 22-gauge needle was advanced in-plane to the midpoint between the transverse process and pleura, and 10 mL of 0.25% bupivacaine was injected at each level. This protocol was adapted from the original technique described by Bhoi et al., with modifications in injection levels and volume.
Sponsors
Ain Shams University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Outcomes Assessor)
Masking description
Patients were sedated during block placement; however, due to the distinct anatomical sites of the two techniques, full patient blinding could not be ensured. Outcome assessors gathering postoperative data were blinded to group allocation, and the anesthesiologists performing the blocks were not engaged in data collection.
Intervention model description
This study used a parallel assignment model involving 88 ASA I-II female patients undergoing modified radical mastectomy. Participants were randomized into two equal groups to receive either an ultrasound-guided PECS II block or a midpoint transverse process to pleura (MTP) block, each with 20 mL of 0.25% bupivacaine. Postoperative analgesic efficacy was assessed using the Visual Analog Scale (VAS), time to first rescue analgesia, total nalbuphine consumption, and incidence of complications over 24 hours.
Eligibility
Sex/Gender
FEMALE
Age
40 Years to 65 Years
Healthy volunteers
No
Inclusion criteria
1. Female patients scheduled for modified radical mastectomy (MRM). 2. Age between 40 and 65 years. 3. American Society of Anesthesiologists (ASA) physical status I-II.
Exclusion criteria
1. Known allergy to local anesthetics. 2. Coagulopathy. 3. Infection at the site of injection. 4. Patient refusal. 5. Inability to understand or use the pain scale.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Post-operative Pain Severity Assessed by VAS at Hour-4 | will be evaluated at hour-4 postoperatively | Visual Analogue Scale is a scale for pain assessment ranging from 0 to 10 where 0 is minimum and means no pain while 10 is maximum and means maximum pain which means worse outcome |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Post-operative Pain Severity Assessed by VAS on Admission to Postanesthesia Care Unit (PACU), at Hour-2, Hour-8, Hour-12, Hour-18 and Hour-24. | 24 hours postoperatively | Comparison between postoperative pain severity after 2 hours, 4 hours, 8 hours, 12 hours, 18 hours and 24 hours postoperative between both groups using visual analogue score Visual Analogue Scale is a scale for pain assessment ranging from 0 to 10 where 0 is minimum and means no pain while 10 is maximum and means maximum pain which means worse outcome |
| Time of First Rescue Analgesia | 24 hours postoperatively | Comparison between both groups regarding the time of first needed dose of nalbuphine |
| Cumulative Post-operative Nalbuphine Consumption in the First 24 Hours | 24 hours postoperatively | Comparison between both groups regarding total consumed nalbuphine in first 24 hours postoperative |
| Incidence of Postoperative Side Effects and Complications | 24 hours postoperatively | Comparison between both groups regarding postoperative side effects and complications |
Countries
Egypt
Contacts
PRINCIPAL_INVESTIGATORAhmed A. Khalifa, MD
Ain Shams University
Participant flow
Recruitment details
This was a single-center, prospective, randomized controlled trial conducted at Ain Shams University Hospital. A total of 112 patients scheduled for modified radical mastectomy were assessed for eligibility between November 2023 and July 2025.
Pre-assignment details
Out of 112 screened patients, 24 were excluded (17 did not meet inclusion criteria, 7 declined participation), leaving 88 enrolled and randomly allocated to Group A (PECS II block, n=44) and Group B (MTP block, n=44). Four participants withdrew consent during follow-up, resulting in 84 completions (42 per group). All remaining participants were included in the final analysis, with no exclusions
Participants by arm
| Arm | Count |
|---|---|
| PECS II block group Forty-four ASA I-II female patients, aged 40-65 years and scheduled for modified radical mastectomy, received an ultrasound-guided PECS II block with 20 mL of 0.25% bupivacaine (10 mL between the pectoralis major and minor, and 10 mL between the pectoralis minor and serratus anterior at the third to fourth ribs). | 42 |
| MTP block group Forty-four ASA I-II female patients, aged 40-65 years and scheduled for modified radical mastectomy, received an ultrasound-guided midpoint transverse process to pleura (MTP) block. A high-frequency linear probe was positioned parasagittally about 3 cm lateral to the midline at the T2 and T6 vertebral levels. A 22-gauge needle was advanced in-plane, and 10 mL of 0.25% bupivacaine was injected at each level. | 42 |
| Total | 84 |
Baseline characteristics
| Characteristic | PECS II block group | MTP block group | Total |
|---|---|---|---|
| Age, Continuous | 42.4 years STANDARD_DEVIATION 5.8 | 41.2 years STANDARD_DEVIATION 4.9 | 41.8 years STANDARD_DEVIATION 5.4 |
| body mass index | 27.9 kilograms per meter square STANDARD_DEVIATION 2.3 | 28.3 kilograms per meter square STANDARD_DEVIATION 2.2 | 28.1 kilograms per meter square STANDARD_DEVIATION 2.25 |
| height | 1.68 meters STANDARD_DEVIATION 0.06 | 1.67 meters STANDARD_DEVIATION 0.05 | 1.675 meters STANDARD_DEVIATION 0.055 |
| Race and Ethnicity Not Collected | — | — | 0 Participants |
| Sex: Female, Male Female | 42 Participants | 42 Participants | 84 Participants |
| Sex: Female, Male Male | 0 Participants | 0 Participants | 0 Participants |
| weight | 78.5 kilograms STANDARD_DEVIATION 8.5 | 79.1 kilograms STANDARD_DEVIATION 8.5 | 78.8 kilograms STANDARD_DEVIATION 8.5 |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 42 | 0 / 42 |
| other Total, other adverse events | 12 / 42 | 23 / 42 |
| serious Total, serious adverse events | 1 / 42 | 0 / 42 |
Outcome results
Primary
Post-operative Pain Severity Assessed by VAS at Zero Time (on Admission to the PACU)
Visual Analogue Scale is a scale for pain assessment ranging from 0 to 10 where 0 is minimum and means no pain while 10 is maximum and means maximum pain which means worse outcome
Time frame: will be evaluated post-operatively at zero time
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| PECS II block group | Post-operative Pain Severity Assessed by VAS at Zero Time (on Admission to the PACU) | 0.3 score on a scale | Standard Deviation 0.5 |
| MTP block group | Post-operative Pain Severity Assessed by VAS at Zero Time (on Admission to the PACU) | 0.3 score on a scale | Standard Deviation 0.5 |
Secondary
Cumulative Post-operative Nalbuphine Consumption in the First 24 Hours
Comparison between both groups regarding total consumed nalbuphine in first 24 hours postoperative
Time frame: 24 hours postoperatively
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| PECS II block group | Cumulative Post-operative Nalbuphine Consumption in the First 24 Hours | 13.3 milligrams | Standard Deviation 3.6 |
| MTP block group | Cumulative Post-operative Nalbuphine Consumption in the First 24 Hours | 8.3 milligrams | Standard Deviation 2.6 |
Secondary
Incidence of Postoperative Side Effects and Complications
Comparison between both groups regarding postoperative side effects and complications
Time frame: 24 hours postoperatively
| Arm | Measure | Group | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| PECS II block group | Incidence of Postoperative Side Effects and Complications | Hematoma | 12 Participants |
| PECS II block group | Incidence of Postoperative Side Effects and Complications | Nausea | 8 Participants |
| PECS II block group | Incidence of Postoperative Side Effects and Complications | vomiting | 3 Participants |
| PECS II block group | Incidence of Postoperative Side Effects and Complications | pneumothorax | 0 Participants |
| MTP block group | Incidence of Postoperative Side Effects and Complications | pneumothorax | 1 Participants |
| MTP block group | Incidence of Postoperative Side Effects and Complications | Hematoma | 9 Participants |
| MTP block group | Incidence of Postoperative Side Effects and Complications | vomiting | 1 Participants |
| MTP block group | Incidence of Postoperative Side Effects and Complications | Nausea | 2 Participants |
Secondary
Post-operative Pain Severity Assessed by VAS at Hour-2, Hour-4, Hour-8, Hour-12, Hour-18 and Hour-24.
Comparison between postoperative pain severity after 2 hours, 4 hours, 8 hours, 12 hours, 18 hours and 24 hours postoperative between both groups using visual analogue score Visual Analogue Scale is a scale for pain assessment ranging from 0 to 10 where 0 is minimum and means no pain while 10 is maximum and means maximum pain which means worse outcome
Time frame: 24 hours postoperatively
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| PECS II block group | Post-operative Pain Severity Assessed by VAS at Hour-2, Hour-4, Hour-8, Hour-12, Hour-18 and Hour-24. | Post-operative pain severity assessed by Visual analogue scale at 2 hours postoperatively. | 1.4 score on a scale | Standard Deviation 0.6 |
| PECS II block group | Post-operative Pain Severity Assessed by VAS at Hour-2, Hour-4, Hour-8, Hour-12, Hour-18 and Hour-24. | Post-operative pain severity assessed by Visual analogue scale at 4 hours postoperatively. | 2.2 score on a scale | Standard Deviation 0.7 |
| PECS II block group | Post-operative Pain Severity Assessed by VAS at Hour-2, Hour-4, Hour-8, Hour-12, Hour-18 and Hour-24. | Post-operative pain severity assessed by Visual analogue scale at 8 hours postoperatively. | 3.2 score on a scale | Standard Deviation 0.6 |
| PECS II block group | Post-operative Pain Severity Assessed by VAS at Hour-2, Hour-4, Hour-8, Hour-12, Hour-18 and Hour-24. | Post-operative pain severity assessed by Visual analogue scale at 12 hours postoperatively. | 3.2 score on a scale | Standard Deviation 0.7 |
| PECS II block group | Post-operative Pain Severity Assessed by VAS at Hour-2, Hour-4, Hour-8, Hour-12, Hour-18 and Hour-24. | Post-operative pain severity assessed by Visual analogue scale at 18 hours postoperatively. | 2.2 score on a scale | Standard Deviation 0.5 |
| PECS II block group | Post-operative Pain Severity Assessed by VAS at Hour-2, Hour-4, Hour-8, Hour-12, Hour-18 and Hour-24. | Post-operative pain severity assessed by Visual analogue scale at 24 hours postoperatively. | 1.7 score on a scale | Standard Deviation 0.5 |
| MTP block group | Post-operative Pain Severity Assessed by VAS at Hour-2, Hour-4, Hour-8, Hour-12, Hour-18 and Hour-24. | Post-operative pain severity assessed by Visual analogue scale at 18 hours postoperatively. | 1.9 score on a scale | Standard Deviation 0.7 |
| MTP block group | Post-operative Pain Severity Assessed by VAS at Hour-2, Hour-4, Hour-8, Hour-12, Hour-18 and Hour-24. | Post-operative pain severity assessed by Visual analogue scale at 2 hours postoperatively. | 1.1 score on a scale | Standard Deviation 0.8 |
| MTP block group | Post-operative Pain Severity Assessed by VAS at Hour-2, Hour-4, Hour-8, Hour-12, Hour-18 and Hour-24. | Post-operative pain severity assessed by Visual analogue scale at 12 hours postoperatively. | 2.9 score on a scale | Standard Deviation 0.6 |
| MTP block group | Post-operative Pain Severity Assessed by VAS at Hour-2, Hour-4, Hour-8, Hour-12, Hour-18 and Hour-24. | Post-operative pain severity assessed by Visual analogue scale at 4 hours postoperatively. | 1.4 score on a scale | Standard Deviation 0.6 |
| MTP block group | Post-operative Pain Severity Assessed by VAS at Hour-2, Hour-4, Hour-8, Hour-12, Hour-18 and Hour-24. | Post-operative pain severity assessed by Visual analogue scale at 24 hours postoperatively. | 1.5 score on a scale | Standard Deviation 0.8 |
| MTP block group | Post-operative Pain Severity Assessed by VAS at Hour-2, Hour-4, Hour-8, Hour-12, Hour-18 and Hour-24. | Post-operative pain severity assessed by Visual analogue scale at 8 hours postoperatively. | 2.5 score on a scale | Standard Deviation 0.5 |
Secondary
Time of First Rescue Analgesia
Comparison between both groups regarding the time of first needed dose of nalbuphine
Time frame: 24 hours postoperatively
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| PECS II block group | Time of First Rescue Analgesia | 7.9 hours | Standard Deviation 1.2 |
| MTP block group | Time of First Rescue Analgesia | 12.8 hours | Standard Deviation 0.8 |