Objective: To compare the haemodynamic effects of identical values of continuous negative external pressure (CNEP) and positive end-expiratory pressure (PEEP) in a group of mechanically ventilated patients.
Setting: General ICU, Vicenza Hospital, Italy.
Patients: 15 consecutive patients, admitted after road accident trauma.
Methods: We compared the haemodynamic effects of ZEEP, 10 cmH2O of PEEP, and 10 cmH2O CNEP, applied in random order, in 15 head trauma patients under going controlled mechanical ventilation; 9 had associated thoracic trauma, while 6 did not have lung involvement. CNEP was obtained with a "poncho".
Results: We observed a significant increase in CI during CNEP, compared with both ZEEP and PEEP 10 cmH2O. Accordingly the oxygen delivery index significantly increased during CNEP, compared with PEEP 10 cmH2O. Conversely, Qs/Qt decreased with CNEP, if compared with PEEP, both in patients with and without lung damage.
Conclusion: CNEP can significantly increase CI in mechanically ventilated patients in patients with and without associated lung damage.