High-Flow Nasal Oxygen vs. Face Mask During Sedoanalgesia in Non-Intubated Thoracoscopic Pericardial Window Surgery

Pericardial effusion may require therapeutic or diagnostic drainage by pericardiocentesis or creation of a surgical "pericardial window." Video-assisted thoracoscopic surgery (VATS) is the preferred minimally invasive approach, but standard practice employs general anesthesia with tracheal intubation. Since the late 1980s, non-intubated VATS (NI-VATS) performed under sedoanalgesia with regional blocks has gained acceptance, offering lower morbidity, shorter recovery, and avoidance of postoperative pulmonary complications-advantages that are especially valuable in elderly or comorbid patients who are at risk of hypotension or cardiac arrest during induction.

During NI-VATS, iatrogenic pneumothorax and underlying cardiac pathology can precipitate perioperative hypoxia. Conventional oxygen delivery (facemask or low-flow nasal cannula at ≤15 L min-¹) may be insufficient. High-flow nasal oxygen therapy (HFNOT) delivers warmed, humidified gas at up to 70 L min-¹ and FiO₂ 0.21-1.00, matching or exceeding peak inspiratory flow, reducing airway resistance, washing out nasopharyngeal dead space, and improving alveolar ventilation. Perioperative data on HFNOT in NI-VATS remain limited.

In this study, the primary objective is to compare the incidence of intraoperative hypoxia (defined as SpO₂ < 92%) in patients receiving high-flow nasal oxygen therapy (HFNOT) versus a conventional oxygen mask (COM) during sedoanalgesia-guided non-intubated video-assisted thoracoscopic (NI-VATS) pericardial window procedures.

Secondary objectives include the comparison of oxygen saturation trends and nadir SpO₂ values; hemodynamic stability (heart rate and mean arterial pressure); arterial blood gas parameters (pO₂, pCO₂, pH, lactate, and base excess); regional cerebral oxygen saturation (NIRS); procedural and recovery times; postoperative pain scores (VAS); the need for intensive care unit admission; length of hospital stay; and the incidence of pulmonary or cardiovascular complications.

Inclusion criteria

• Adults aged 18 to 75 years
• Scheduled for elective video-assisted thoracoscopic pericardial window procedure under sedoanalgesia
• ASA Physical Status Classification I-III
• Able and willing to provide written informed consent

Exclusion criteria

• Age <18 or >75 years
• ASA Physical Status ≥ IV
• Body Mass Index (BMI) > 30 kg/m²
• Need for inotropic support at enrollment
• Preoperative hemodynamic instability
• Symptomatic respiratory disease (e.g., pneumonia, nasal congestion, asthma attack)
• Diagnosed neuromuscular disorder
• Diagnosed tracheal stenosis
• Local infection at the site of regional block application
• Coagulopathy or bleeding diathesis
• Pregnancy
• Patients refusing sedoanalgesia
• Patients refusing study participation
• Conversion to general anesthesia or use of supraglottic airway intraoperatively