Anesthesia and intraoperative high-frequency oscillatory ventilation during burn surgery

Area of Science:

• Anesthesiology
• Critical Care Medicine
• Trauma Surgery

Background:

• Severe acute respiratory distress syndrome (ARDS) in burn patients often necessitates high-frequency oscillatory ventilation (HFOV).
• Burn patients requiring surgery while on HFOV present unique anesthetic challenges.
• Maintaining HFOV during intraoperative procedures is crucial for managing severe ARDS.

Purpose of the Study:

• To describe the technique for providing and maintaining intraoperative HFOV in adult burn patients.
• To evaluate the feasibility and safety of intraoperative HFOV in this patient population.

Main Methods:

• Retrospective analysis of hospital and anesthesia records of adult burn patients on HFOV undergoing surgery.
• Data collected included patient demographics, burn characteristics, intraoperative HFOV settings, and physiological parameters.
• Analysis of oxygenation (PaO₂/FiO₂ ratio, oxygenation index) and ventilation (PaCO₂) before, during, and after surgery.

Main Results:

• 57 procedures on 36 patients were analyzed; 69% had inhalation injury.
• Intraoperative HFOV settings: mean airway pressure 33 cm H₂O, frequency 5 Hz, FiO₂ 0.7.
• No significant changes in oxygenation (PaO₂/FiO₂ ratio, oxygenation index) were observed.
• A transient, significant increase in PaCO₂ was noted intraoperatively, including during prone positioning.
• HFOV was discontinued in 3 cases due to respiratory or hemodynamic instability.
• No intraoperative deaths occurred; in-hospital mortality was 33%.

Conclusions:

• Intraoperative HFOV is feasible and safe for the majority of burn patients with severe ARDS undergoing surgery.
• The technique allows for the maintenance of adequate oxygenation.
• Transient intraoperative hypercapnia is an expected finding but does not typically lead to hemodynamic compromise or oxygenation issues.