Hypercapnic respiratory failure in COPD patients - Response to therapy

Introduction: The clinical course of patients with acute exacerbations of underlying COPD presenting with hypercapnic respirator failure was reviewed. : of 138 episodes of hyercapnic respiratory failure Methods: This was a retrospective review (Paco(2) greater than or equal to 50 mm Hg and pH less than or equal to 7,35), Patients were admitted to the West Los Angeles VAMC Medical Intensive Care Unit between 1990 and 1994, Results: Of the 138 hypercapnic episodes, 74 (54%) required intubation, Comparison was made with the 64 cases in which patients responded to medical therapy, Patients requiring intubation had a greater severity of illness, with a higher APACHE II (Acute Physiology and Chronic Health Evaluation II) score (18 +/- 5 vs 16 +/- 4; p < 0,01), higher W'BC, higher serum BUN, and greater acidosis (pH, 7.26 +/- 0.07 vs 7.28 +/- 0.06; p = 0,08), Those with the most severe acidosis (pH < 7,20) had the highest intubation rate (70%) and shortest time to intubation (2 +/- 2 h), and they required the longest period of time to respond to medical therapy (69 +/- 60 h). With an initial pH of < 7.25, there was a consistently higher intubation rate. Conversely, those with an initial pH of 7.31 to 7.35 were less likely to be intubated (45%), had a longer time to intubation (13 +/- 18 h), and had a more rapid response to medical therapy (30 +/- 18 h). Of those patients requiring intubation, most (78%) were intubated within 8 h of presentation, and the vast majority (93%) by 24 h. Of those patients responding to medical therapy, half(52%) recovered within 24 h and the vast majority (92%) recovered within 72 h, Conclusions: This study provides a better characterization of the response to therapy of COPD patients with hypercapnic respiratory failure. This should be useful in limiting or omitting medical therapy in high-risk patients, thereby avoiding delays in intubation as well as providing a framework for continued therapy in those more likely to improve.