Protective Ventilatory Approaches to One-Lung Ventilation: More than Reduction of Tidal Volume

Esophageal Balloon-Directed Ventilator Management for Postpneumonectomy Acute Respiratory Distress Syndrome

Objective

Postpneumonectomy patients may develop acute respiratory distress syndrome (ARDS). There is a paucity of data regarding the optimal management of mechanical ventilation for postpneumonectomy patients. Esophageal balloon pressure monitoring has been used in traditional ARDS patients to set positive end-expiratory pressure (PEEP) and minimize transpulmonary driving pressure (ΔP_L), but its clinical use has not been previously described nor validated in postpneumonectomy patients. The primary objective of this report was to describe the potential clinical application of esophageal pressure monitoring to manage the postpneumonectomy patient with ARDS.

Design

Case report. Setting. Surgical intensive care unit (ICU) of a university-affiliated teaching hospital. Patient. A 28-year-old patient was involved in a motor vehicle collision, with a right main bronchus injury, that required a right-sided pneumonectomy to stabilize his condition. In the perioperative phase, they subsequently developed ventilator-associated pneumonia, significant cumulative positive fluid balance, and ARDS. Interventions. Prone positioning and neuromuscular blockade were initiated. An esophageal balloon was inserted to direct ventilator management. Measurements and Main Results. V_T was kept around 3.6 mL/kg PBW, ΔP_L at ≤14 cm H₂O, and plateau pressure at ≤30 cm H₂O. Lung compliance was measured to be 37 mL/cm H₂O. PEEP was optimized to maintain end-inspiratory transpulmonary pressure (P_L) < 15 cm H₂O, and end-expiratory P_L between 0 and 5 cm H₂O. The maximal ΔP_L was measured to be 11 cm H₂O during the care of this patient. The patient improved with esophageal balloon-directed ventilator management and was eventually liberated from mechanical ventilation.

Conclusions

The optimal targets for V_T remain unknown in the postpneumonectomy patient. However, postpneumonectomy patients with ARDS may potentially benefit from very low V_T and optimization of PEEP. We demonstrate the application of esophageal balloon pressure monitoring that clinicians could potentially use to limit injurious ventilation and improve outcomes in postpneumonectomy patients with ARDS. However, esophageal balloon pressure monitoring has not been extensively validated in this patient population.

A nationwide survey of intraoperative management for one-lung ventilation in Taiwan: time to accountable for diversity in protective lung ventilation

BACKGROUND

There is a major paradigm shift for intraoperative mechanical ventilator support by the introduction of lung protective ventilation strategies to reduce postoperative pulmonary complications and improve overall clinical outcomes in non-thoracic surgeries. However, there is currently a lack of standardized practice guideline for lung protection during thoracic surgeries that require one-lung ventilation (OLV). This study aimed to collect the expert opinions of the thoracic anesthesiologists in perioperative care for OLV surgery in Taiwan.

METHODS

This prospective cross-sectional study was undertaken in 16 tertiary hospitals in Taiwan from January to February 2019. A structured survey form was distributed across the participating hospitals and the thoracic anesthesiologists were invited to complete the form voluntarily. The survey form consisted of three parts, including the basic information of the institutional anesthesia care standards, ventilatory settings for a proposed patient receiving OLV surgery and expert opinions on OLV.

RESULTS

A total of 71 thoracic anesthesiologists responded to the survey. Double-lumen tubes are the most commonly used (93.8%) airway devices for OLV. The most commonly recommended ventilator setting during OLV is a tidal volume of 6-7 ml/kg PBW (67.6%) and a PEEP level of 4-6 cmH₂O (73.5%). Dual controlled ventilator modes are used by 44.1% of the anesthesiologists. During OLV, high oxygen fraction (FiO₂ > 0.8) is more commonly supplemented to achieve an oxygen saturation higher than 94%. The consensus of anesthesiologists on the indices for lung protection in thoracic surgery is considerably low. Large majority of the anesthesiologists (91.5%) highly recommend that an international clinical practice guideline on the protective lung ventilation strategy for thoracic anesthesia should be established.

CONCLUSIONS

This study found that the thoracic anesthesiologists in Taiwan share certain common practices in ventilator support during OLV. However, they are concerned about the lack of fundamental clinical evidences to support the beneficial outcomes of the current lung protective strategies applicable to OLV. Large-scale trials are needed to form an evidence-based clinical practice guideline for thoracic anesthesia.