This prospective cohort study will evaluate the association between the overall burden of regional anesthesia and early clinical outcomes in adult patients with polytrauma.

Patients with severe trauma often experience pain from multiple injury sites and may require more than one peripheral nerve block or continuous regional anesthesia catheter. While regional anesthesia can improve pain control and reduce opioid use, multiple blocks and catheters may also increase treatment complexity, local anesthetic exposure, motor weakness, and monitoring challenges.

The study will prospectively collect data on the number and type of regional anesthesia procedures, local anesthetic exposure, catheter use, pain intensity, opioid consumption, mobility, complications, and early recovery outcomes. The goal is to determine whether increasing regional anesthesia burden is associated with improved analgesia, functional recovery, or increased risk in polytrauma patients.

Background

Regional anesthesia has become an essential component of multimodal analgesia in trauma care, providing effective pain relief, reducing opioid requirements, improving respiratory function, and facilitating early rehabilitation. Advances in ultrasound-guided techniques have enabled clinicians to perform multiple peripheral nerve blocks and continuous catheter techniques in patients with complex polytrauma involving several anatomical regions.

Despite these advantages, there is currently no evidence-based framework defining the optimal extent of regional anesthesia in polytrauma patients. In contemporary trauma practice, some patients receive one regional block, whereas others undergo multiple single-injection blocks combined with continuous peripheral nerve catheters. Although increasing the number of regional techniques may improve analgesia, excessive regional anesthesia may also increase cumulative local anesthetic exposure, procedural burden, motor impairment, monitoring complexity, and the potential risk of adverse events. The concept of an optimal "regional anesthesia burden" has not previously been investigated.

Study Rationale

This study introduces the concept of Regional Anesthesia Burden (RAB), representing the overall intensity of regional anesthesia delivered during the acute management of polytrauma. Rather than evaluating individual block techniques, the study will investigate the cumulative impact of regional anesthesia on pain control, opioid requirements, functional recovery, and early clinical outcomes.

Regional Anesthesia Burden will be characterized using objective procedural variables, including:

number of peripheral nerve blocks; number of continuous regional anesthesia catheters; cumulative local anesthetic exposure during the first 72 hours; number of anatomical regions covered by regional anesthesia; expected motor block burden; total number of regional anesthesia procedures performed.

Study Design

This is a prospective observational cohort study. Consecutive adult patients with polytrauma receiving regional anesthesia as part of routine clinical care will be enrolled. No interventions beyond standard clinical practice will be performed.

Clinical management, including the choice of regional anesthesia technique, catheter placement, local anesthetic selection, concentration, and infusion regimen, will remain entirely at the discretion of the treating anesthesiologist according to institutional protocols.

Patients will be followed prospectively during the first seven days after injury. Pain intensity, opioid consumption, respiratory function, mobilization, complications, and recovery parameters will be recorded using standardized assessment tools.

Study Objectives

The primary objective is to determine whether increasing Regional Anesthesia Burden is associated with improved early clinical outcomes or whether excessive regional anesthesia is associated with diminishing clinical benefit and increased treatment-related risk.

Secondary objectives include evaluation of the relationship between Regional Anesthesia Burden and opioid consumption, functional recovery, pulmonary complications, motor impairment, intensive care unit length of stay, hospital length of stay, and regional anesthesia-related complications.

Scientific Significance

The BLOCK-TRAUMA study is expected to provide the first prospective clinical evidence regarding the optimal extent of regional anesthesia in polytrauma patients. The results may contribute to future evidence-based recommendations regarding the appropriate use of multiple peripheral nerve blocks and continuous regional anesthesia techniques in severely injured patients and help define the balance between maximizing analgesia and minimizing procedural burden and complications.

Inclusion Criteria:

• Adults aged 18 years or older.
• Diagnosis of polytrauma, defined as traumatic injuries involving two or more anatomical regions.
• Injury Severity Score (ISS) ≥16.
• Hospital admission within 48 hours after injury.
• Requirement for acute pain management during hospital treatment.
• Receipt of at least one ultrasound-guided peripheral nerve block and/or continuous peripheral nerve catheter as part of routine clinical care.
• Ability to collect clinical data on regional anesthesia procedures, analgesic use, pain assessment, and early recovery outcomes.
• Written informed consent provided by the patient or legally authorized representative, according to local regulations.

Exclusion Criteria:

• Age younger than 18 years.
• Isolated single-system injury without polytrauma. ISS <16.
• Expected survival less than 24 hours after admission.
• Severe traumatic brain injury or impaired consciousness preventing reliable pain and functional assessment, unless validated behavioral pain scales can be used.
• Known allergy or contraindication to local anesthetics.
• Pre-existing severe neuromuscular disease affecting motor function assessment.
• Chronic opioid therapy before injury.
• Pregnancy.
• Enrollment in another interventional trial that may affect pain management or functional recovery outcomes.
• Missing essential data required for assessment of Regional Anesthesia Burden.

The study population will consist of consecutive adult patients with polytrauma admitted to a Level I trauma center who receive one or more ultrasound-guided peripheral nerve blocks and/or continuous peripheral nerve catheters as part of routine multimodal pain management. Patients will be managed according to institutional trauma and regional anesthesia protocols. Prospective clinical data will be collected to evaluate the relationship between Regional Anesthesia Burden and pain control, opioid consumption, functional recovery, regional anesthesia-related complications, and early clinical outcomes during hospitalization and at 3-month follow-up.

Access to de-identified individual participant data, the study protocol, statistical analysis plan, and supporting documentation will be provided to qualified researchers whose proposed use of the data has been approved by the principal investigator. Requests must include a methodologically sound research proposal and will require execution of a data use agreement. Data will be provided in a secure electronic format in accordance with institutional policies and applicable ethical and legal requirements.