The purpose of this study was to investigate the population pharmacokinetics of vancomycin in patients undergoing open heart surgery. In this observational pharmacokinetic study, multiple blood samples were drawn over a 48-h period of intravenous vancomycin in patients who were undergoing open heart surgery. Blood samples were analyzed using an Architect i4000SR immunoassay analyzer. Population pharmacokinetic models were developed using Monolix 4.4 software. Pharmacokinetic-pharmacodynamic (PK-PD) simulations were performed to explore the ability of different dosage regimens to achieve the pharmacodynamic targets. A total of 168 blood samples were analyzed from 28 patients. The pharmacokinetics of vancomycin are best described by a two-compartment model with between-subject variability in clearance (CL), the volume of distribution of the central compartment (), and volume of distribution of the peripheral compartment (). The CL and the of vancomycin were related to creatinine CL (CL), body weight, and albumin concentration. Dosing simulations showed that standard dosing regimens of 1 and 1.5 g failed to achieve the PK-PD target of AUC/MIC > 400 for an MIC of 1 mg/liter, while high weight-based dosing regimens were able to achieve the PK-PD target. In summary, the administration of standard doses of 1 and 1.5 g of vancomycin two times daily provided inadequate antibiotic prophylaxis in patients undergoing open heart surgery. The same findings were obtained when 15- and 20-mg/kg doses of vancomycin were administered. Achieving the PK-PD target required higher doses (25 and 30 mg/kg) of vancomycin.

The purpose of this study was to investigate the population pharmacokinetics (PK) of cefuroxime in patients undergoing coronary artery bypass graft (CABG) surgery. In this observational pharmacokinetic study, multiple blood samples were collected over a 48-h interval of intravenous cefuroxime administration. The samples were analyzed by using a validated high-performance liquid chromatography (HPLC) method. Population pharmacokinetic models were developed using Monolix (version 4.4) software. Pharmacokinetic-pharmacodynamic (PD) simulations were performed to explore the ability of different dosage regimens to achieve the pharmacodynamic targets. A total of 468 blood samples from 78 patients were analyzed. The PK for cefuroxime were best described by a two-compartment model with between-subject variability on clearance, the volume of distribution of the central compartment, and the volume of distribution of the peripheral compartment. The clearance of cefuroxime was related to creatinine clearance (CL). Dosing simulations showed that standard dosing regimens of 1.5 g could achieve the PK-PD target of the percentage of the time that the free concentration is maintained above the MIC during a dosing interval () of 65% for an MIC of 8 mg/liter in patients with a CL of 30, 60, or 90 ml/min, whereas this dosing regimen failed to achieve the PK-PD target in patients with a CL of ≥125 ml/min. In conclusion, administration of standard doses of 1.5 g three times daily provided adequate antibiotic prophylaxis in patients undergoing CABG surgery. Lower doses failed to achieve the PK-PD target. Patients with high CL values required either higher doses or shorter intervals of cefuroxime dosing. On the other hand, lower doses (1 g three times daily) produced adequate target attainment for patients with low CL values (≤30 ml/min).

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Objective:To examine the validity of central venous oxygen saturation (ScvO2) as a numerical substitution of mixed venous oxygen saturation (SvO2) in adult patients undergoing normothermic on pump beating coronary artery bypass grafting (CABG).Materials and Methods:Prospective clinical observational study was done at King Khalid University Hospital, King Saud University, Riyadh, Kingdom of Saudi Arabia. Thirty four adult patients scheduled for coronary artery surgery were included. Patients were monitored by a pulmonary artery catheter (PAC) as a part of our routine intraoperative monitoring. SvO2 and ScvO2 were simultaneously measured 15 minutes (T1) and 30 minutes (T2) after induction of anesthesia, 15 and 30 minutes after initiation of cardiopulmonary bypass (T3 and T4), and 15 and 30 minutes after admission to intensive care unit (T5 and T6).Results:ScvO2 showed higher reading than SvO2 all through our study. Our results showed perfect positive statistically significant correlation between SvO2 and ScvO2 at all data points. Individual mean of difference (MOD) between both the readings at study time showed MOD of 1.34 and 1.44 at T1 and T2 simultaneously. This MOD was statistically insignificant, but after on pump beating normothermic bypass was initiated; MOD was 5.2 and 4.4 at T3 and T4 with high statistical significance. In ICU, MOD continues to have high statistical significance, MOD was 6.3 at T5 and at T6 it was 4.6.Conclusions:In on pump beating CABG patients; ScvO2 and SvO2 are not interchangeable numerically. ScvO2 is useful in the meaning of trend; our data suggest that ScvO2 is equivalent to SvO2 , only in the course of clinical decisions as long as absolute values are not required.

Introduction: Crohn's disease (CD) is classically described as a chronic granulomatous inflammatory bowel disease, laryngeal and other otolaryngologic manifestations of CD are uncommon and may be subtle, as laryngeal involvement by CD has been reported in only six cases in the medical literature.Objective: we describe a case of an Egyptian man with extra intestinal CD that involves the supraglottic and subglottic regions, but with skipping of the glottis. Conclusion:This case demonstrates the need to be oriented with extra intestinal CD especially if the lesion was mainly laryngeal, and therefore, a high degree of suspicion is necessary to diagnose the disease, as early recognition is imperative, and we recommend a detailed study on a large number of patients with inflammatory bowel disease (IBD) and CD on the long term effect of colectomy on development of extra intestinal manifestations, as we suspect that colectomy might have triggered the onset of airway involvement many years later.