Pulmonary function testing:
FEV1 of 4.25 L 03% predicted
FVC of 5.99 L or 119% predicted
FEV1/FVC ratio of 71 compared to 82 predicted.
Maximum voluntary ventilation was 179 L per minute or 105% predicted
Cardiopulmonary exercise test:
Exercise protocol: The risks and benefits of progressive maximal cardiopulmonary exercise testing were explained to the patient. Informed, written consent was obtained prior to the start of the procedure and placed in the chart. The patient was exercised on a cycle ergometer to a symptom limited maximum with progressively increasing work load at 20 W per minute increments. Continuous oxygen saturation, EKG, and expired gas analysis were performed. Serial blood pressures were obtained. The patient reached a maximum workload of 162 W and appeared to give a good effort. The patient stopped primarily due to shortness of breath.
Results:
Maximum oxygen consumption: The patient's the VO2 max was 2.01 L/min which represents 85% of the predicted maximum. When normalized for body weight, the VO2 max was 28.3 mL/min/kg actual body weight. The VO2/work rate was low.
Cardiac response: Resting ECG demonstrated normal sinus rhythm. With progressive exercise the heart rate increased from a baseline of 80 up to 155. After recovery, the heart rate decreased to 151 after 1 minute. At its maximum, the heart rate was 84% of the predicted maximum. The O2 pulse was 4 mL/beat at rest and 13 mL/beat at maximal work that represents 101% of the predicted maximum. The blood pressure at rest was 115/74 and it maximum work was 162/75. A ventilatory threshold was observed at 0.85 L/min which represented 35% of the predicted VO2 maximum.
Ventilatory response: The patient's resting ventilation was 9 L/min and increased to 60 L/min at maximal exercise, representing 35% of the predicted maximum and compared to the measured maximum voluntary ventilation of 179 L per minute. The respiratory rate increased from 12 to 33 at maximal exercise. The volumes increased from 0.7 L to 2.1 L at maximal exercise.
Gas exchange: The patient's oxygen saturation was 97% at rest and 97% at maximal exercise. End-tidal CO2 was 35 at rest and 40 at maximal exercise. Ve/CO2 at anaerobic threshold was 25. Arterial blood gases were 7.39 /44.5/76 at rest and 7.35 /39.5/102 with maximal exercise. Serum lactate levels increased from 0.8 to to 9.24 at maximal exercise.
Interpretation: This cardiopulmonary exercise test demonstrates a maximal test as evidenced by the presence of plateau in VO2 with increasing workload, peak RER>1.15, and dyspnea and or leg discomfort >5 on BORG scale. The patient reached V02 max of 2.01 L/min that represents 85% of the predicted maximum suggesting a normal exercise tolerance. The pattern demonstrated on today's test is most consistent with a cardiac limitation to exercise. This is evidenced by a maximum heart rate approaching 90% of predicted, presence of an anaerobic threshold, appropriate increase in blood pressure, absence of desaturation, normal decrease in calculated dead space. The anaerobic threshold did occur earlier than expected which may indicate a degree of deconditioning.By report, patient noticed desaturation with activity but within the study his oxygen saturations remained in the mid 90s and his PaO2 appropriately increased over the course of the study. There were no significant arrhythmias noted.There was a very significant breathing reserve only achieving 60 L/min compared to the 179 L/min maximum voluntary ventilation. No dynamic hyperinflation or flow limitation was noted.