Effect of whole lung lavage on the elimination of CO2 and dead space in patients with pulmonary alveolar proteinosis Katayama N., Shono A., Fujihara T., Kakuta N., Saito Y. Shimane University Faculty of Medicine, Dept of Anaesthesiology, Izumo City, Japan Background Results Pulmonary alveolar proteinosis (PAP) is a rare disease characterized by the progressive accumulation of alveolar surfactant and hypoxemia. Whole lung lavage (WLL) is considered to be a standard therapy to improve oxygenation and quality of life in patients with PAP. Although a large amount of warmed saline is used in WLL, there are no established response criteria to evaluate its therapeutic effect. Please export the PowerPoint document as a PDF (File – Save as – PDF) and upload the PDF into the system. Please use the font in the document or a similar one and do not use a font size smaller than 16. Goal of Study Perioperatively investigate the improvement in efficient alveolar ventilation after WLL by measuring elimination of CO2 and dead space. VTCO2,br at T2 and T3 increased by 3.7% and 5.4%, respectively, compared to T1 Cases 2 patients diagnosed with PAP were scheduled for WLL. Case 1: 62-year-old man with a symptom of dyspnea on exertion. Hugh-Jones classification 3 Case 2: 48-year-old woman with no symptoms. Infiltrative shadow in chest X-ray was presented 3 years ago. Case 1 Case 2 Shunt-related dead space decreased by 20.8% at T3 (mean ± SD: 0.32 ± 5.4) compared to T1 (mean ± SD:0.40 ± 4.5) Chest CT in both cases showed a diffuse crazy paving pattern in the bilateral lung. Methods Mean EVLWI increased from 11.2 ml/kg at T1 to 14.1 ml/kg at T3. Measurements Evaluation for 4 trials of WLL in 2 patients ✓CO2 elimination per breath (VTCO2, br) 　 Indirect calorimetry (the breath by breath technique) ✓ Shunt-related dead space 　 Enghoff’s modification of Bohr’s dead space formula ✓ Extravascular lung water index (EVLWI) 　 Thermodilution technique (PiCCO) Volume of saline Time of WLL(min) P/F ratio T1 T2 T3 Case 1 Trial 1 6000 ml 211 418 233 307 Trial 2 10600 ml 357 398 177 290 Case 2 3460 ml 239 339 243 347 11150 ml 379 313 180 349 Time points of measurements 　T　 WLL ICU　　　 T1 Before initiation of WLL T2 end of WLL T3 12 hours after WLL Discussion 　Increase in VTCO2,br and decrease in shunt-related dead space after WLL indicated that WLL increased efficient ventilation area related to gas exchange by the drainage of accumulated surfactant in alveoli. However, lavage fluid might be partially absorbed into pulmonary interstitium, resulting in an increase in extravascular lung water. 　Responsiveness to WLL is normally subjectively evaluated by clarity of the effluent. However, the improvement of gas exchange can be detected by physiologically monitoring these parameters. Schema of VTCO2,br and dead space (according to volumetric capnography) Enghoff’s modification of Bohr’s dead space VTCO2,br Conclusions VDEnghoff / VT = PaCO2 PaCO2 – PĒCO2 Area under the curve of volumetric capnogram For the first time, we confirmed the usefulness of using these parameters for the assessment of improved gas exchange by WLL. 1) R. Borie, et al. Pulmonary alveolar proteinosis. Eur Respir Rev 2011;20:98-107 2) Suarez-Sipmann F, et al. Volumetric capnography: the time has come. Curr Opin Crit care 2014;20:333-339 References