Forti et al. Journal of Medical Case Reports 2010, 4:339 http://www.jmedicalcasereports.com/content/4/1/339 Page 4 of 5 Figure 1 The patient before high frequency percussive ventilation. H2O on CV to 27 cm H2O on HFPV. There was no change in haemodynamic variables. The tidal volume increased as a result of the increasing lung compliance which had been improved by the HFPV. We found that there was a decrease in the RVSWI, LVSWI, PVRI and PAWP due to a reduction of MArP compared to the CV resulting in a lower afterload. Conclusion This case report shows the improvement in oxygenation and ventilation in a cardiac surgery patient. To the best of our knowledge, there has been no previous published report on HFPV in cardiac surgery intensive care. Lung injury is a frequent postoperative complication in such Figure 2 The patient after high frequency percussive ventilation treatment. Figure 3 Arterial partial pressure of oxygen increasing after high frequency percussive ventilation treatment. patients. HFPV is a safe ventilatory modality that improves gas exchange when CV does not work. In patients with an acute respiratory distress syndrome the intrathoracic pressure is greater than for a normal venti- lated lung. An augmented intrathoracic pressure increases the afterload and reduces the stroke volume of the right ventricle with an increased systolic pulmonary pressure due to an increase in the pulmonary vessels resistance. It is important to reduce the mean airway pressure and decrease the interference to the cardiac cycle. With HFPV the mean airway pressure is lower than with conventional ventilation and so it may, therefore, Table 3 High frequency percussive ventilation (HFPV) setting HFPV post 2 hours HFPV post 6 hours HFPV post 12 hours Percussive rate (rate/min) Convective rate (rate/min) PEEP (cm H2O) PIP (cm H2O) MArP (cm H2O) IT (sec) ET (sec) I:E i:e FiO2 (%) 650 5 14 46 16 2,0 10.8 1:7.0 1:1 1 650 5 14 46 16 1,9 10.9 1:6.9 1:1 0.8 650 5 14 43 13 2,1 10.7 1:7.1 1:1 0.6 The high peak inspiratory pressure (PIP) level does not indicate a very high- pressure level, because the sample point is on the patient, directly connected with the endotracheal tube. PIPs at the carina are approximately one-third the level set on the HFPV. In the conventional ventilators the sampling point is inside the ventilator, 1.80 m away from the patient, the mean airway pressure (MArP) measure depends on the dissipated energy through the ventilator tubes. PEEP, positive end expiratory pressure.