Bianzina S, Cornara P, Rodi G, Tavazzi G, Iotti GA, Mojoli F, Braschi A
Intensive Care Medicine Experimental 2016, 4(Suppl 1):27;116
Introduction: Pulmonary alveolar proteinosis (PAP) is a rare disorder characterized by a perturbation in surfactant homeostasis, resulting in its accumulation within alveolar spaces, with a consequent development of severe hypoxemia. Whole lung lavage (WLL) is a complex procedure, dedicated to those patients affected by a severe condition not responsive to medical treatment.
Objective: To analyze the evolution of gas exchanges during WLL, evaluating PaO2 variations during the different phases of the procedure.
Patients and method: We enrolled 27 patients with PAP (16 males, age 15-64 years),who underwent WLL in our ICU between 2010 and 2015. WLL was conducted in general anesthesia, using selective endotracheal tubes. It consisted of different phases, for each lung: 1) bipulmonary mechanical ventilation in supine position at FiO2 1 and ZEEP; 2) bipulmonary ventilation in supine position with PEEP; 3) monopulmonary ventilation in supine position, in order to achieve complete atelectasis of the contralateral lung; 4) monopulmonary ventilation in lateral position, with the ventilated lung downward; 5) lavage of the whole atelectatic lung with liquid tidal ventilation at different levels of hydrostatic lavage pressure. We collected data regarding patient gas exchanges by performing several blood gas analysis during the different steps of WLL. We expressed data as mean ± standard deviation (SD).
Results: Figure 95 shows the mean values of PaO2 during the different phases of WLL. During bipulmonary ventilation gas exchanges improved in response to FiO2 1 and PEEP. Monopulmonary ventilation, instead, induced a clear reduction of PaO2, which increased in lateral position and during liquid tidal ventilation, with a substantial effect of elevated hydrostatic lavage pressures. The wide SD indicates an uneven response of gas exchanges in the studied population.
Conclusions: The pathophysiology of PAP is characterized by altered alveolocapillary diffusion and intrapulmonary shunt, thus significantly responsive to FiO2 and PEEP, respectively. During monopulmonary ventilation, shunt is reduced by the lateral position, which provides a better perfusion of the ventilated lung, and the elevated hydrostatic lavage pressures, which are able to limit perfusion in the contralateral lung under WLL.
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