Physiologic Effects of Positive End-Expiratory Pressure in Patients with Chronic Obstructive Pulmonary Disease during Acute Ventilatory Failure and Controlled Mechanical Ventilation
- 1 January 1993
- journal article
- Published by American Thoracic Society in American Review of Respiratory Disease
- Vol. 147 (1) , 5-13
- https://doi.org/10.1164/ajrccm/147.1.5
Abstract
Dynamic hyperinflation and intrinsic positive end-expiratory pressure (PEEPi) are observed in patients with chronic obstructive pulmonary disease (COPD) and flow limitation. Several reports suggest that PEEP levels approaching PEEPi reduce inspiratory load due to PEEPi, without further hyperinflation. Hence PEEP should not increase intrathoracic pressure or affect hemodynamics and gas exchange. To verify this hypothesis, the effects of PEEP (0 to 15 cm H2O) on respiratory mechanics, hemodynamics, and gas exchange were studied in nine COPD patients during controlled mechanical ventilation. PEEP levels approaching PEEPi (9.8 +/- 0.5 cm H2O) did not affect the expiratory flow/volume relationship, confirming the presence of flow limitation. PEEP levels of 5 and 10 cm H2O did not change lung volume and PEEPi in the respiratory system (PEEPtot,rs) and chest wall (PEEPtot,cw) or affect hemodynamics and gas exchange. When applied PEEP overcame PEEPi, changes in lung volume and the expiratory flow/volume relationship were observed. PEEPtot,rs and PEEPtot,cw also increased. Under these circumstances, PEEP increased static elastance in both the respiratory system and the chest wall, reducing cardiac index and affecting hemodynamics and gas exchange. Our data show that in mechanically ventilated COPD patients with PEEPi due to flow limitation, PEEP levels exceeding the 85% of PEEPi (Pcrit) caused further hyperinflation and compromised hemodynamics and gas exchange.Keywords
This publication has 31 references indexed in Scilit:
- Estimating Left Ventricular Filling Pressure during Positive End-Expiratory Pressure in HumansAmerican Review of Respiratory Disease, 1991
- Continuous Positive Airway Pressure Reduces Work of Breathing and Dyspnea during Weaning from Mechanical Ventilation in Severe Chronic Obstructive Pulmonary DiseaseAmerican Review of Respiratory Disease, 1990
- Ventilation-Perfusion Mismatching in Chronic Obstructive Pulmonary Disease during Ventilator WeaningAmerican Review of Respiratory Disease, 1989
- Detrimental Effects of Positive End-expiratory Pressure during Controlled Mechanical Ventilation of Patients with Severe Airflow ObstructionAmerican Review of Respiratory Disease, 1989
- Should PEEP Be Used in Airflow Obstruction?American Review of Respiratory Disease, 1989
- The Effects of Positive Expiratory Pressure on Isovolume Flow and Dynamic Hyperinflation in Patients Receiving Mechanical VentilationAmerican Review of Respiratory Disease, 1989
- Impact of PEEP on lung mechanics and work of breathing in severe airflow obstructionJournal of Applied Physiology, 1988
- Respiratory Mechanics during the First Day of Mechanical Ventilation in Patients with Pulmonary Edema and Chronic Airway ObstructionAmerican Review of Respiratory Disease, 1988
- Measurement of respiratory mechanics using the siemens servo ventilator 900CPediatric Pulmonology, 1987
- A Multiple Comparison Procedure for Comparing Several Treatments with a ControlJournal of the American Statistical Association, 1955