There was also no statistically significant change inoxygen saturation or heart rate at any of the testing intervalswhen compared to baseline results. Four individualswere noted to have cardiac irregularities duringthe postural drainage with or without percussion.These arrhythmias consisted of occasional ventricularpremature beats in one individual and combined atrialand ventricular premature beats in the remainingthree. No patient with arrhythmia was symptomatic orexperienced desaturation. None of the arrhythmiasresulted in an alteration in blood pressure.The total amount of sputum expectorated by thesubjects during the testing period ranged from 0 to110 ml. One subject produced no sputum. Five subjectsproduced 1 to 10ml of sputum. Five subjects produced12 to 30 ml. Only two subjects produced morethan 30 ml of sputum. All patients were instructed tosave their sputum produced during the day of testing.Total daily sputum production ranged from 30 to 360ml. The percentage of total daily sputum productionobtained during the physical therapy ranged from 2percent to 50 percent (mean 19 percent) of the totaldaily sputum production in the 12 patients who producedsputum during the physical therapy session .The total amount of sputum produced varied duringthe testing period. In all but five patients, the first twotesting periods (initial baseline pulmonary functiontests and ten minutes of postural drainage and pulmonaryfunction tests) accounted for the greatest amountof sputum production. As a group, the patients expectorated20 percent of their total sputum volume duringthe baseline period, 48 percent after postural drainage,15percent after percussion and postural drainage,and 17 percent in the 30-minute rest period. Expectorationduring the baseline period resulted fromcoughing induced during pulmonary function testing.Four of 13 subjects expectorated sputum during thisperiod. All were large daily sputum producers (~50mllday).