Second Affiliated Hospital, Sun Yat-Sen University
Third Affiliated Hospital, Sun Yat-Sen University
Shaoguan People's Hospital
Dongguan People's Hospital
The center hospital of Wuhan
Age
18–80
Sex
ALL
Healthy volunteers
Not accepted
You may be eligible if
1. Adult COPD Patients with chronic hypercapnic respiratory failure established on home noninvasive ventilation for at least 1 month
2. Patients are in a clinically stable state,without any changes of medication during the previous 4 weeks.
You may not be if
1. patient's refusal to participate
2. Patients with evidence of acute respiratory failure i.e.patients with worsening of symptoms during the previous 2 weeks, a pH ,7.35, or with signs of respiratory infection
