General Versus Regional Anesthesia in Peripheral Arterial Surgery

Official title

Impact of General Versus Regional Anesthesia on the Incidence of Postoperative Pulmonary Complications in Peripheral Arterial Surgery: a Multicenter Randomized Clinical Trial

Overview

This multicenter, prospective, randomized clinical trial aims to compare the effects of spinal (neuraxial) anesthesia with spontaneous ventilation versus general anesthesia with mechanical ventilation on the incidence of postoperative pulmonary complications in adult patients undergoing elective lower limb revascularization surgery. A total of 594 patients with symptomatic peripheral arterial disease will be randomly assigned to receive either spinal anesthesia with sedation or general anesthesia with mechanical ventilation. The primary outcome is the incidence of postoperative pulmonary complications within 30 days or until hospital discharge, including pneumonia, respiratory failure, pleural effusion, atelectasis, and other defined respiratory events. Secondary outcomes include cardiovascular events, hemodynamic instability, renal injury, delirium, extrapulmonary complications, adverse events in the operated limb, ICU and hospital length of stay, and mortality. The study will be conducted at Hospital de Clínicas de Porto Alegre, Hospital Nossa Senhora da Conceição, and other participating Brazilian centers, with an expected start date in July 2025 and completion in December 2029.

Detailed description

This is a prospective, randomized, multicenter clinical trial designed to evaluate the impact of the anesthetic technique-general anesthesia with mechanical ventilation versus spinal (neuraxial) anesthesia with spontaneous ventilation-on the incidence of postoperative pulmonary complications in patients undergoing elective peripheral arterial revascularization surgery. The study population will include 594 adult patients (ASA II-IV) with symptomatic critical limb ischemia, scheduled for elective lower limb revascularization at tertiary hospitals in Brazil. Patients will be randomized into two groups: Group 1 will receive spinal anesthesia with intravenous sedation and supplemental nasal oxygen; Group 2 will receive general anesthesia with controlled mechanical ventilation using lung-protective strategies (tidal volume 6-8 mL/kg and PEEP 5 cmH₂O).

The primary outcome is the incidence of postoperative pulmonary complications within 30 days after surgery or until hospital discharge. These include pneumonia, respiratory failure, pleural effusion, atelectasis, pneumothorax, aspiration pneumonitis, bronchospasm, ARDS, pulmonary embolism, and exacerbation of preexisting respiratory disease, defined according to internationally recognized criteria.

Secondary outcomes include:

1. major cardiovascular complications (nonfatal myocardial infarction, acute coronary syndrome, cardiogenic shock); 2. hemodynamic complications (prolonged hypotension or distributive shock requiring vasopressors); 3. other extrapulmonary complications such as acute kidney injury, stroke, delirium, sepsis, surgical limb complications (e.g., graft thrombosis, amputation), and thromboembolic events (e.g., DVT, PE); 4. ICU and hospital length of stay, PACU time, and 30-day or in-hospital mortality.

Data collection will include perioperative gasometric evaluation, detailed intraoperative hemodynamic and ventilatory monitoring, analgesia and antiemetic usage, and adverse events tracking through predefined time points (intraoperative, immediate postoperative, and up to 30 days after surgery). Sample size calculation is based on detecting a reduction in pulmonary complications from 25% in the general anesthesia group to 15% in the spinal anesthesia group, with a power of 80% and a two-tailed alpha of 0.05. Randomization will be performed using computer-generated block sequences, and outcome assessors and statisticians will be blinded. The statistical analysis will follow the intention-to-treat principle and include regression modeling to control for potential confounders such as comorbidities and operative duration.

The study will begin in July 2025 and is expected to be completed by December 2029. Results will be published in peer-reviewed journals and used to inform perioperative management strategies in vascular surgery.

Interventions

• Procedure Spinal Anesthesia
  Participants will receive subarachnoid (spinal) anesthesia with 15-20 mg of isobaric bupivacaine 0.5% and 100 μg of intrathecal morphine. Clonidine (1 μg/kg) may be added at the discretion of the anesthesiologist. Sedation will be achieved with intravenous midazolam (up to 5 mg), fentanyl (up to 100 μg), and/or target-controlled infusion of propofol. Patients will remain spontaneously breathing throughout the procedure and receive supplemental oxygen via nasal cannula.
• Procedure General Anesthesia
  Participants will undergo general anesthesia induced with intravenous propofol (1.5-2.5 mg/kg) or etomidate (0.2-0.3 mg/kg), remifentanil (0.2-0.4 μg/kg/min), and rocuronium (0.6 mg/kg), followed by endotracheal intubation and controlled mechanical ventilation. Maintenance will include continuous remifentanil infusion and inhaled sevoflurane. Ventilation parameters will follow a protective strategy (tidal volume 6-8 mL/kg predicted body weight and PEEP of 5 cmH₂O).

Primary outcome measures

• Incidence of Postoperative Pulmonary Complications [Time frame: Up to 30 days after surgery.]

Secondary outcome measures (5)

• Incidence of Major Cardiovascular Complications [Time frame: Up to 30 days after surgery.]
• Incidence of Hemodynamic Complications [Time frame: Up to 24 hours after surgery.]
• Incidence of Extrapulmonary Complications [Time frame: Up to 30 days after surgery.]
• Length of Stay in Post-Anesthesia Care Unit (PACU) [Time frame: Up to 30 days after surgery.]
• 30-Day Mortality [Time frame: Up to 30 days after surgery.]

Eligibility criteria

Inclusion criteria

• Adults aged ≥18 years
• ASA physical status II to IV
• Scheduled for elective peripheral arterial revascularization of the lower limbs
• Diagnosis of symptomatic peripheral arterial disease with critical limb ischemia
• Able and willing to provide informed consent

Exclusion criteria

• Body mass index (BMI) > 40 kg/m²
• Emergency vascular surgery
• History of lung resection surgery
• Persistent hemodynamic instability preoperatively
• History of bronchial asthma or chronic corticosteroid therapy
• History of neuromuscular disorders
• Current use of anticoagulants or antiplatelet agents contraindicating spinal anesthesia
• Contraindications to spinal anesthesia (e.g., patient refusal, infection at puncture site, increased intracranial pressure, inability to cooperate due to agitation or cognitive impairment)
• Acute vascular obstruction or other vascular complications not consistent with elective revascularization

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Double blind

Primary purpose

Treatment

Study locations

Brazil · 1 center

• Andre Prato Schmidt — Porto Alegre

Publications

• Schmidt AP, Silvello D, Filho CTB, Bergmann D, Ferreira LEC, Nolasco MF, Pires TD, Braga WC, Andrade CF. Effects of Neuraxial or General Anesthesia on the Incidence of Postoperative Pulmonary Complications in Patients Undergoing Peripheral Vascular Surgery: A Randomized Controlled Trial. J Cardiothorac Vasc Anesth. 2025 Mar;39(3):724-732. doi: 10.1053/j.jvca.2024.12.027. Epub 2024 Dec 21. PMID 39779428
• Schmidt AP, Marques AJ, Reinstein AR, Bevilacqua Filho CT, Carmona MJC, Auler JOC Jr, Felix EA, Andrade CF. Effects of protective mechanical ventilation during general anesthesia in patients undergoing peripheral vascular surgery: A randomized controlled trial. J Clin Anesth. 2020 May;61:109656. doi: 10.1016/j.jclinane.2019.109656. Epub 2019 Nov 26. No abstract available. PMID 31784303
• Li A, Dreksler H, Nagpal SK, Brandys T, Jetty P, Dubois L, Parsons Leigh J, Stelfox HT, McIsaac DI, Roberts DJ. Outcomes After Neuraxial or Regional Anaesthesia Instead of General Anaesthesia for Lower Limb Revascularisation Surgery: A Systematic Review and Meta-Analysis of Randomised and Non-Randomised Studies. Eur J Vasc Endovasc Surg. 2023 Mar;65(3):379-390. doi: 10.1016/j.ejvs.2022.10.046. Epu PMID 36336286

Identifiers

NCT: NCT06953128 · 86625325.0.1001.5327

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗