Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Median tidal volume variable at different times for the group treated with preoperative physiotherapy and without physical therapy preoperatively. Friedman test for comparison of moments in each group and Mann Whitney test to compare the groups at each time, *P<0.05.
