A difference is a difference if it makes a difference.
Tramèr
M R
MR
Garnerin
P
P
D015360:Analgesia, Epidural / Q000009:adverse effects*; D000701:Analgesics, Opioid / Q000009:adverse effects*; D006801:Humans; D015201:Meta-Analysis as Topic; D010149:Postoperative Pain / Q000188:drug therapy*; D001261:Pulmonary Atelectasis / Q000209:etiology*; D013223:Statistics as Topic
D000701:Analgesics, Opioid