Statistical considerations and sample size calculation
postoperative pain
CAVITY
A worldwide accepted practice after open or minimally invasive oesophagectomy is to place apical and basal chest drains for complete drainage of the pleural cavity. The sample size calculation is based on a comparison of double versus single chest drain applications after pulmonary lobectomies. In a prospective randomized trial, the mean values of postoperative pain according to the visual analogue scale (VAS) on the second postoperative day were 4.28 in the single-drain group 