Physiologic definitions of obliterative bronchiolitis in heart-lung and double lung transplantation: a comparison of the forced expiratory flow between 25% and 75% of the forced vital capacity and forced expiratory volume in one second.
METHODS
A comparison of the forced expiratory flow between 25% and 75% of the forced vital capacity (FEF25-75) and forced expiratory volume in 1 second (FEV1) was conducted for the detection of obstructive airway disease as an early manifestation of obliterative bronchiolitis. Pulmonary function tests performed on heart-lung and double lung transplant recipients between March 1981 and March 1983 were reviewed. Thirty patients were identified who showed progressive deterioration in pulmonary function after transplantation. Ratios determining proportionate decreases were calculated from measurements of absolute values for the FEF25-75 and FEV1 at the point when the FEF25-75 reached < 70% and < or = 30% of predicted, divided by baseline values obtained before the decline in function. Similar ratios were obtained for FEV1 and FEF25-75 at the point the FEV1 declined > or = 20% from its baseline value.


RESULTS
Comparison of the ratios for the FEF25-75 and FEV1 at FEF25-75 values < 70% and < or = 30% of predicted and a similar comparison when the FEV1 declined > or = 20% from baseline showed a greater proportional decrease in FEF25-75 than FEV1 (p < 0.01). With the use of the FEF25-75, declines in airway function were detected earlier. After transplantation a decline in FEF25-75 to < 70% of predicted occurred approximately 112 days before a 20% decline a FEV1.


CONCLUSIONS
The FEF25-75 is more sensitive than the FEV1 for the early detection of obliterative bronchiolitis. A presumptive diagnosis of obliterative bronchiolitis can be made with physiologic criteria, providing infection or acute rejection has been ruled out. When conducting epidemiologic studies or for vital statistics we propose that a decline in FEF25-75 to < 70% be used to define the onset of obliterative bronchiolitis.
Patterson
G M
GM
Department of Medicine, Morehouse School of Medicine, Atlanta, Ga., USA.
Wilson
S
S
Whang
J L
JL
Harvey
J
J
Agacki
K
K
Patel
H
H
Theodore
J
J
D000328:Adult; D000403:Airway Resistance / Q000502:physiology; D001989:Bronchiolitis Obliterans / Q000175:diagnosis / Q000503:physiopathology*; D003937:Diagnosis, Differential; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology*; D006084:Graft Rejection / Q000175:diagnosis / Q000503:physiopathology; D016041:Heart-Lung Transplantation / Q000502:physiology*; D006801:Humans; D016040:Lung Transplantation / Q000502:physiology*; D008297:Male; D008450:Maximal Midexpiratory Flow Rate / Q000502:physiology*; D008875:Middle Aged; D011183:Postoperative Complications / Q000175:diagnosis / Q000503:physiopathology*; D014797:Vital Capacity / Q000502:physiology*