Anesthesia, Regional, Diaphragmatic Paralysis, Proximal Humeral Fracture
Conditions
Keywords
Proximal Humeral Fracture, Elderly, Costoclavicular Block, Interscalene Block, Diaphragmatic Paralysis, Randomized Controlled Trial
Brief summary
Background: Proximal humeral fractures are common in elderly patients and often require surgical fixation (open reduction and internal fixation). Traditional regional anesthesia techniques, such as the interscalene brachial plexus block, may provide incomplete pain relief in the medial upper arm area and carry a high risk of hemidiaphragmatic paralysis, which can lead to breathing difficulties. Objective: This study aims to evaluate whether an optimized nerve block strategy-ultrasound-guided costoclavicular brachial plexus block combined with superficial cervical plexus block and T2 thoracic paravertebral block-improves anesthetic success and reduces diaphragm dysfunction compared to the traditional interscalene approach in elderly patients undergoing proximal humeral fracture surgery. Study Design: This is a multicenter, prospective, randomized, controlled, double-blind (participants and outcome assessors), superiority clinical trial. Population: A total of 356 elderly patients (aged ≥65 years) with unilateral proximal humeral fractures scheduled for open reduction and internal fixation via an anterior surgical approach will be enrolled from three centers in Shanghai, China. Intervention: Participants will be randomly assigned in a 1:1 ratio to one of two groups: * Experimental Group (Optimized Strategy): Receives ultrasound-guided costoclavicular brachial plexus block + superficial cervical plexus block + T2 thoracic paravertebral block (0.375% ropivacaine 20 mL for brachial plexus, 0.25% ropivacaine 10 mL for each of the other blocks). * Control Group (Traditional Strategy): Receives ultrasound-guided interscalene brachial plexus block + superficial cervical plexus block + T2 thoracic paravertebral block (same drug regimen). All nerve blocks will be performed under ultrasound guidance by a single anesthesiologist. Patients and outcome assessors will be blinded to group assignment; the performing anesthesiologist cannot be blinded due to the distinct anatomical approaches. Main Outcomes: * Primary Outcome: Nerve block success rate, defined as no pain or only mild pain requiring no rescue analgesics (e.g., intravenous opioids, conversion to general anesthesia, or local infiltration) during surgery. * Key Secondary Outcomes: Rate of hemidiaphragmatic paralysis (assessed by ultrasound M-mode); rate of conversion to general anesthesia; postoperative pain (NRS, 0-10) at 24 hours; perioperative stress biomarkers (cortisol, ACTH, IL-6, HMGB-1, CRP, galectin-3); and postoperative shoulder function recovery. Safety Monitoring: Adverse events, including unplanned conversion to general anesthesia, respiratory depression, pneumothorax, and severe hemidiaphragmatic paralysis, will be recorded and managed according to predefined protocols. An independent Data Monitoring Committee will review safety data and conduct interim analyses for futility. Study Duration: The study is expected to take approximately 24 months from first patient enrollment to final follow-up completion. Ethical Approval: This study has been approved by the Ethics Committee of Shanghai Tongren Hospital. Approvals from the ethics committees of the other participating centers (Shanghai Sixth People's Hospital and Shanghai Xuhui Central Hospital) will be obtained before study initiation at those sites.
Detailed description
See brief summary.
Interventions
Ultrasound-guided brachial plexus block performed at the costoclavicular space. The patient is placed in the lateral decubitus position with the operative side up. A high-frequency ultrasound probe is used to identify the brachial plexus at the costoclavicular space. Using an in-plane technique, 0.375% ropivacaine 20 mL is injected. This intervention is administered once prior to surgery.
PROCEDUREInterscalene Brachial Plexus Block
Ultrasound-guided brachial plexus block performed at the interscalene groove. The patient is placed in the lateral decubitus position with the operative side up. A high-frequency ultrasound probe is used to identify the brachial plexus between the anterior and middle scalene muscles. Using an in-plane technique, 0.375% ropivacaine 20 mL is injected. This intervention is administered once prior to surgery.
PROCEDURESuperficial Cervical Plexus Block
Ultrasound-guided superficial cervical plexus block. The patient is placed in the lateral decubitus position with the operative side up. A high-frequency ultrasound probe is used to identify the superficial cervical plexus at the lateral border of the sternocleidomastoid muscle. Using an in-plane technique, 0.25% ropivacaine 10 mL is injected. This intervention is administered once prior to surgery.
PROCEDURET2 Thoracic Paravertebral Block
Ultrasound-guided T2 thoracic paravertebral block. The patient is placed in the lateral decubitus position with the operative side up. A low-frequency ultrasound probe is used to identify the T2 transverse process, rib, pleura, and costotransverse ligament. Using an in-plane technique, 0.25% ropivacaine 10 mL is injected. This intervention is administered once prior to surgery.
Sponsors
Shanghai Tong Ren Hospital
Shanghai 6th People's Hospital
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Outcomes Assessor)
Masking description
The statistician is blinded to group assignment. Data management personnel are also blinded; all case report forms are entered using anonymized codes, and group allocation is separately sealed by a third-party statistical unit until database lock. In addition, the following measures ensure participant blinding: during the block procedure, the participant's head, neck, and upper limb are covered with a sterile drape, preventing visualization of the puncture site and ultrasound images. After the procedure, all puncture sites are covered with identical sterile dressings to avoid revealing group assignment via puncture location.
Intervention model description
Multicenter, stratified dynamic competition randomization (minimization randomization) with a 1:1 parallel assignment. An independent third-party statistical unit generates the randomization sequence and performs allocation concealment through a central randomization system. Stratification factors: study center, ASA grade (I-II vs III), COPD status, and Neer classification (2-part vs 3-4 part). After informed consent is obtained, a trained research nurse at each center submits the participant's baseline information via an encrypted central randomization system, which immediately returns a unique randomization number and group assignment. The allocation sequence is concealed from all researchers, anesthesiologists, and participants until unblinding at the end of the study. Patients, outcome assessors, and statisticians are blinded; the anesthesiologist performing the blocks cannot be blinded due to distinct anatomical approaches.
Eligibility
Sex/Gender
ALL
Age
65 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Signed informed consent * Age ≥65 years * BMI \<30 * American Society of Anesthesiologists (ASA) physical status I to III * Unilateral proximal humeral fracture scheduled for open reduction and internal fixation via an anterior surgical approach (including deltopectoral approach and anteromedial deltoid approach)
Exclusion criteria
* Inability to perform T2 thoracic paravertebral block for any reason * Coagulation dysfunction or current use of anticoagulant therapy * History of upper extremity nerve injury or phrenic nerve injury * Severe polytrauma * Preoperative uncontrolled severe respiratory dysfunction (resting SpO2 \<90% or home oxygen therapy, or FEV1 \<30% of predicted value) * Preoperative uncontrolled asthma, pulmonary infection, pneumothorax, or history of prior lung surgery * Preoperative uncontrolled hypertension with admission systolic blood pressure \>180 mmHg or diastolic blood pressure \>110 mmHg * Preoperative uncontrolled coronary artery disease, valvular heart disease, or arrhythmia * Any condition that precludes nerve block performance (e.g., local infection or swelling at the puncture site, inability to change position) * Inability to communicate or cooperate with anesthesia administration (e.g., language barrier, intellectual disability, Alzheimer's disease, Parkinson's disease) * Allergy to ropivacaine or any other contraindication to nerve block
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Nerve Block Success Rate | Intraoperative (assessed immediately after surgical incision and throughout the procedure) | Nerve block success is defined as no pain or only mild pain during surgery, with no need for rescue analgesics (including intravenous opioids, conversion to general anesthesia, or local infiltration). Block failure is defined as significant pain requiring any rescue analgesic measure to complete the surgery. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Sensory Block in Four Regions | 20 minutes after nerve block completion | Sensory block is assessed using pinprick test at 20 minutes after nerve block completion in four regions: distal clavicular region, deltoid region, medial upper arm region, and lateral upper arm region. Grading: 0=no block (sharp pain), 1=partial block (reduced pain sensation), 2=complete block (no pain sensation). |
| Vasoactive Medication Requirements | Intraoperative | Total intraoperative doses of vasoactive medications including urapidil, ephedrine, phenylephrine, and atropine. |
| Rate of Hemidiaphragmatic Paralysis | 35 minutes after nerve block completion | Hemidiaphragmatic paralysis is assessed by ultrasound M-mode (sniff test). Complete paralysis: diaphragm excursion reduced by ≥75% from baseline or paradoxical movement. Partial paralysis: reduction of 25%-75%. No paralysis: reduction \<25%. |
| Proportion of Surgeries Completed with Remifentanil Assistance | Intraoperative | Proportion of patients who require intravenous remifentanil (0.25 μg/kg/min) to tolerate the surgery without conversion to general anesthesia. |
| Conversion Rate to General Anesthesia | Intraoperative | Proportion of patients requiring conversion to general anesthesia (laryngeal mask airway with sevoflurane) due to inadequate block despite remifentanil assistance. |
| Postoperative Pain Score (NRS) | At 1, 2, 4, 6, 12, and 24 hours postoperatively | Pain intensity assessed using the Numeric Rating Scale (NRS, 0=no pain, 10=worst possible pain) at rest and during movement. |
| Perioperative Stress Biomarkers | At four time points: preoperatively, 1 hour after surgery start, 30 minutes postoperatively, and 24 hours postoperatively | Plasma concentrations of cortisol, ACTH, IL-6, HMGB-1, CRP, and galectin-3 measured by ELISA. |
| Incidence of Adverse Events | Intraoperative and up to 24 hours postoperatively | Adverse events include hypotension, hypertension, bradycardia, tachycardia, respiratory depression, pneumothorax, and severe hemidiaphragmatic paralysis requiring intervention. |
Countries
China
Contacts
STUDY_CHAIRJunfeng Zhang, MD
Shanghai Tong Ren Hospital
PRINCIPAL_INVESTIGATORWenyi Zhang, MMed
Shanghai Tong Ren Hospital
PRINCIPAL_INVESTIGATORHui Zhang, MD
Shanghai 6th People's Hospital
PRINCIPAL_INVESTIGATORZhen Zeng, MD
Shanghai Xuhui Central Hospital
Outcome results
None listed