Table 2.

Clinical characteristics of the study patients.

Characteristic	Group A	Group B
Sex (male: female)	18:22	21:19*
Age (years)	64.2 ± 9.9	62.5 ± 9.6*
APACHEⅡ score	20.2 ± 5.0	19.8 ± 6.2*
Weight (kg)	71.5 ± 10.5	70.2 ± 11.2*
Height (cm)	172.8 ± 11.6	175.1 ± 12.5*
COPD (n)	25	24*
ARDS (n)	11	11*
Severe asthma (n)	2	2*
Others (n)	2	3*

Note: *p > 0.05, compared with group A; COPD = chronic obstructive pulmonary disease; ARDS = acute respiratory distress syndrome.