Peri-and Postoperative Subcutaneous Adipose Tissue Cefazolin Determination Using Microdialysis in Morbidly Obese and Non-obese Patients

The investigators hypothesize that cefazolin perfusion to subcutaneous adipose tissue is reduced in morbidly obese patients. The primary objective of this exploratory pilot study is therefore to investigate target site (subcutaneous adipose tissue) penetration of cefazolin in morbidly obese patients and non-obese patients. The investigators aim to examine whether and how cefazolin plasma concentrations are predictive of subcutaneous (target) cefazolin concentrations. Possible factors of influence on the distribution of cefazolin (tissue perfusion, body weight, distribution of adipose tissue, other) will be identified.