Breathing frequency and use of expiratory muscles do influence the dynamic positive end-expiratory pressure.
End-expiratory air trapping due to obstructive airway disease can be estimated through the measurement of intrinsic positive end-expiratory pressure PEEPi. The influence of breathing-frequency and use of expiratory muscles on PEEPi were measured in 10 normal and 10 chronic bronchitic patients (COPD). Insignificant control values of PEEPi increased to measurable values at high breathing rate in normal subjects. Control values were higher in COPD patients and increased at fast breathing rate. When corrected for the use of expiratory muscles according to simultaneous gastric pressure drop, PEEPi decreased in COPD, but still increased at high rate. We conclude that modifying the respiratory rate can increase PEEPi values independently of the severity of airway obstruction and the use of expiratory muscles. Before estimating the pathological value of a PEEPi measurement or evaluating the effects of a treatment, we always need to know the simultaneous breathing frequency.
El Khawand
Ch
Ch
Department of Pneumology, Mont-Godinne University Hospital, Catholic University of Louvain, B-5530 Yvoir, Belgium.
Vanpee
D
D
Rousseau
L
L
Jamart
J
J
Delaunois
L
L
D000328:Adult; D000704:Analysis of Variance; D005541:Forced Expiratory Volume / Q000502:physiology; D005652:Functional Residual Capacity / Q000502:physiology; D006801:Humans; D008875:Middle Aged; D018467:Positive-Pressure Respiration, Intrinsic / Q000503:physiopathology*; D029424:Pulmonary Disease, Chronic Obstructive / Q000503:physiopathology*; D012119:Respiration; D012131:Respiratory Insufficiency / Q000503:physiopathology; D012132:Respiratory Muscles / Q000502:physiology*; D014797:Vital Capacity / Q000502:physiology