2. HISTORY The patient is a 37 year-old Hispanic Man who complained of chest pain and a productive cough at night and after running. The cough started about 5 months before the evaluation.
3. HISTORY The patient also noted shortness of breath when lying flat in bed. He had a minimal smoking history (3 pack-years) but had worked as a welder for 25 years. He had one brother who was diagnosed with asthma.
4. HISTORY Previous pulmonary function studies indicated moderate obstruction, but the patient reported worsening cough and breathlessness with exertion.
5. Pulmonary Function Testing Baseline spirometry(3 months prior to EIA test) PrebronchodilatorPostbronchodilator Pred Actual %Pred Actual %Pred %Chng FVC (L) 4.39 5.10 116 5.09 116 0 FEV1 (L) 3.46 2.79 81 3.22 93 15 FEV1 % 79 55 63 PEF (L/s) 9.08 6.89 76 6.90 76 0
6. Interpretation of baseline Spirometry This patient's baseline spirometry, performed 3 months before the EIA evaluation, demonstrates moderate obstruction (FEV1% = 55%) even though his FEV1 is 81% of the expected value. In addition, he shows a 15% and 430-ml increase in FEV1 following inhaled bronchodilator. Because the symptoms were limiting the patient in his job, the referring physician wanted to determine to what extent his obstruction worsened with exertion.
7. Exercise test (Flow volume loops recorded during exercise) Stand Walk Speed 2.0 3.0 3.0 3.0 3.0 % Grade 0% 7% 7% 7% 6% Time 2:00 1:00 2:00 2:00 2:00 1:00 HR 99 110 136 140 144 142 VE (L/min) 14.8 38.3 43.6 54.1 60.7 57.3
8. Interpretation of Exercise Test The exercise evaluation was performed appropriately. The target HR range for this patient was 130 to 147 beats per minute (80% to 90% of predicted maximal HR). The target ventilation range was 36 to 54 L/min (40% to 60% of the FEV1×35). On the day of the exercise test, the patient's FEV1 was 2.56 L.
9. Interpretation of Exercise Test After a 1-minute warm-up, he walked for 7 minutes with his HR and ventilation within their respective target ranges. The treadmill resistance was decreased slightly during the final minute to prevent his HR from exceeding 90% of predicted and to allow him to continue.
11. Interpretation of Exercise Challenge and Flow Volume Loops Flow volume loops were recorded every 2 minutes during the exercise and superimposed on the maximal flow volume curve (shown in the first panel above). All of the tidal breathing loops show expiratory flows are very near the maximal flow the subject could generate. There is very little ventilatory reserve on expiration or inspiration. The patient demonstrates significant flow limitation during exercise.
12. Exercise changes with spirometry Pred % Pred Baseline 5 minutes Post Rx FVC 4.39 103% 4.53 2.61 2.54 %Change -42% -7% FEV1 3.46 74% 2.56 1.44 2.54 %Change -44% -1% PEF 9.08 58% 5.23 3.19 5.29 %Change -39% 1%
13. Interpretation to Exercise changes with Spirometry Post exercise spirometry show a marked fall in FVC, FEV1, and PEF after 5 minutes. This pattern is consistent with significant exercise-induced bronchospasm. The induced obstruction was rapidly reversed with inhaled bronchodilators.
14. Cause of symptoms This patient's symptoms appear to be directly related to the results of his exercise test. The patient complained of chest pain and cough; both of these symptoms can be caused by hyperreactive airways. Chest pain is often associated with cardiac disease but may actually be "chest tightness" or "chest discomfort" upon further investigation. The patient did have moderate airway obstruction at rest.
15. Cause of symptoms Normally an EIA test would not be indicated in a patient with documented reversible airway obstruction. In this case the exercise evaluation quantified the extent of the hyperreactivity by demonstrating an even further decrease in FEV1 following exertion. The patient displayed flow limitation in his tidal breathing, which explains dyspnea during exertion. Exercise-induced bronchospasm typically occurs immediately after exertion. The marked decrease in flows upon completing exercise documents the rather severe nature of the response in this particular patient's airways.
16. Treatment The patient was started on a combination of inhaled corticosteroids and long-acting -agonists, with fasting-acting -agonists for emergency relief. Unfortunately, he had to leave his job as a welder because of the continued exposure to dust and fumes and because of the level of exertion required by the occupation.
