TY - JOUR
T1 - Effects of lung volume reduction surgery on gas exchange and breathing pattern during maximum exercise
AU - Criner, Gerard J.
AU - Belt, Patricia
AU - Sternberg, Alice L.
AU - Mosenifar, Zab
AU - Make, Barry J.
AU - Utz, James P.
AU - Sciurba, Frank
N1 - Funding Information:
The NETT was supported by contracts with the National Heart, Lung, and Blood Institute (NO1HR76101, NO1HR76102, NO1HR76103, NO1HR76104, NO1HR76105, NO1HR76106, NO1HR76107, NO1HR76108, NO1HR76109, NO1HR761010, NO1HR76111, NO1HR76112, NO1HR76113, NO1HR76114, NO1HR76115, NO1HR76116, NO1HR76118, and NO1HR76119), the Centers for Medicare and Medicaid Services, and the Agency for Healthcare Research and Quality.
PY - 2009/5/1
Y1 - 2009/5/1
N2 - Background: The National Emphysema Treatment Trial studied lung volume reduction surgery (LVRS) for its effects on gas exchange, breathing pattern, and dyspnea during exercise in severe emphysema. Methods: Exercise testing was performed at baseline, and 6, 12, and 24 months. Minute ventilation (V̇E), tidal volume (VT), carbon dioxide output (V̇CO2), dyspnea rating, and workload were recorded at rest, 3 min of unloaded pedaling, and maximum exercise. PaO2, PaCO2, pH, fraction of expired carbon dioxide, and bicarbonate were also collected in some subjects at these time points and each minute of testing. There were 1,218 patients enrolled in the study (mean [± SD] age, 66.6 ± 6.1 years; mean, 61%; mean FEV 1, 0.77 ± 0.24 L), with 238 patients participating in this substudy (mean age, 66.1 ± 6.8 years; mean, 67%; mean FEV1, 0.78 ± 0.25 L). Results: At 6 months, LVRS patients had higher maximum V̇E (32.8 vs 29.6 L/min, respectively; p = 0.001), V̇CO2, (0.923 vs 0.820 L/min, respectively; p = 0.0003), VT (1.18 vs 1.07 L, respectively; p = 0.001), heart rate (124 vs 121 beats/min, respectively; p = 0.02), and workload (49.3 vs 45.1 W, respectively; p = 0.04), but less breathlessness (as measured by Borg dyspnea scale score) [4.4 vs 5.2, respectively; p = 0.0001] and exercise ventilatory limitation (49.5% vs 71.9%, respectively; p = 0.001) than medical patients. LVRS patients with upper-lobe emphysema showed a downward shift in PaCO2 vs V̇CO2 (p = 0.001). During exercise, LVRS patients breathed slower and deeper at 6 months (p = 0.01) and 12 months (p = 0.006), with reduced dead space at 6 months (p = 0.007) and 24 months (p = 0.006). Twelve months after patients underwent LVRS, dyspnea was less in patients with upper-lobe emphysema (p = 0.001) and non-upper-lobe emphysema (p = 0.007). Conclusion: During exercise following LVRS, patients with severe emphysema improve carbon dioxide elimination and dead space, breathe slower and deeper, and report less dyspnea.
AB - Background: The National Emphysema Treatment Trial studied lung volume reduction surgery (LVRS) for its effects on gas exchange, breathing pattern, and dyspnea during exercise in severe emphysema. Methods: Exercise testing was performed at baseline, and 6, 12, and 24 months. Minute ventilation (V̇E), tidal volume (VT), carbon dioxide output (V̇CO2), dyspnea rating, and workload were recorded at rest, 3 min of unloaded pedaling, and maximum exercise. PaO2, PaCO2, pH, fraction of expired carbon dioxide, and bicarbonate were also collected in some subjects at these time points and each minute of testing. There were 1,218 patients enrolled in the study (mean [± SD] age, 66.6 ± 6.1 years; mean, 61%; mean FEV 1, 0.77 ± 0.24 L), with 238 patients participating in this substudy (mean age, 66.1 ± 6.8 years; mean, 67%; mean FEV1, 0.78 ± 0.25 L). Results: At 6 months, LVRS patients had higher maximum V̇E (32.8 vs 29.6 L/min, respectively; p = 0.001), V̇CO2, (0.923 vs 0.820 L/min, respectively; p = 0.0003), VT (1.18 vs 1.07 L, respectively; p = 0.001), heart rate (124 vs 121 beats/min, respectively; p = 0.02), and workload (49.3 vs 45.1 W, respectively; p = 0.04), but less breathlessness (as measured by Borg dyspnea scale score) [4.4 vs 5.2, respectively; p = 0.0001] and exercise ventilatory limitation (49.5% vs 71.9%, respectively; p = 0.001) than medical patients. LVRS patients with upper-lobe emphysema showed a downward shift in PaCO2 vs V̇CO2 (p = 0.001). During exercise, LVRS patients breathed slower and deeper at 6 months (p = 0.01) and 12 months (p = 0.006), with reduced dead space at 6 months (p = 0.007) and 24 months (p = 0.006). Twelve months after patients underwent LVRS, dyspnea was less in patients with upper-lobe emphysema (p = 0.001) and non-upper-lobe emphysema (p = 0.007). Conclusion: During exercise following LVRS, patients with severe emphysema improve carbon dioxide elimination and dead space, breathe slower and deeper, and report less dyspnea.
KW - COPD
KW - Cardiopulmonary exercise
KW - Emphysema
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U2 - 10.1378/chest.08-1625
DO - 10.1378/chest.08-1625
M3 - Article
C2 - 19420196
AN - SCOPUS:65949088799
SN - 0012-3692
VL - 135
SP - 1268
EP - 1279
JO - CHEST
JF - CHEST
IS - 5
ER -