{'fraction_non_alphanumeric': 0.03391304347826087, 'fraction_numerical': 0.02782608695652174, 'mean_word_length': 4.961139896373057, 'pattern_counts': {'":': 0, '<': 1, '<?xml version=': 0, '>': 1, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Plasma and tissue cefazolin concentrations in obese patients undergoing cesarean delivery and receiving differing pre-operative doses of drug.

BACKGROUND
Patients undergoing cesarean delivery typically receive a 1-g to 2-g dose of cefazolin as pre-operative antibacterial prophylaxis. This traditional dosage may not provide an adequate tissue concentration of cefazolin in obese patients during the peri-operative period. This study compared the tissue concentrations of prophylactic cefazolin administered as a either a 2-g or a 4-g dose prior to cesarean delivery in obese patients.


METHODS
Twenty obese patients (first trimester body mass index [BMI] >35) who underwent cesarean delivery completed this randomized study. Eleven patients received 2 g of cefazolin, and nine received 4 g. Blood and subcutaneous tissues were collected at the times of the incision and closure. Myometrial biopsies were collected at uterine closure. A cefazolin concentration threshold of 4 mcg/g for tissue samples was used as a surrogate adequate concentration. Plasma and tissue cefazolin concentrations were compared for the two doses.


RESULTS
Mean plasma, umbilical cord, and myometrial cefazolin concentrations were significantly higher in the 4-g treatment group (p<0.05). Subcutaneous incision site tissue obtained at time of incision creation also was significantly higher in the 4-g group than in the 2-g group (40.11±24.10 mcg/g vs. 18.36±6.68 mcg/g; p=0.0005). Subcutaneous tissue concentrations at closure were significantly different in the two dosage groups (34.89±17.42 mcg/g vs. 21.73±16.02 mcg/g; p=0.044). All tissue samples were above the target of 4 mcg/g. Body morphometry did not correlate with the variability in cefazolin tissue concentration. No surgical site infections, endometritis, or other adverse effects were observed.


CONCLUSIONS
Administering a prophylactic dose of 4 g of cefazolin produced blood and tissue cefazolin concentrations that were significantly higher than concentrations obtained from a 2-g dose in patients with BMIs between 35 and 60 kg/m(2) undergoing cesarean delivery. It is unclear if the larger cefazolin dose produces a more protective anti-infective effect than that obtained with the more traditional 2-g dose for cesarean delivery in obese patients.