Pharmacokinetics of Vancomycin in Critically Ill Patients Undergoing Sustained Low-Efficiency Dialysis.

INTRODUCTION: Vancomycin pharmacokinetic data in critically ill patients receiving sustained low-efficiency dialysis (SLED) is limited. Published data using vancomycin with intermittent hemodialysis and continuous renal replacement therapy may not be applicable to hybrid dialysis modalities such as SLED. Current drug references lack recommendations for vancomycin dosing in patients receiving SLED. OBJECTIVE: The objective of this study was to determine vancomycin pharmacokinetics during SLED. METHODS: A total of 20 patients who were critically ill with oliguric or anuric renal failure who received vancomycin and SLED were included in the study. Surrounding one SLED session, serum vancomycin blood samples were drawn before the initiation of SLED, at the termination of SLED, and 4 hours after completion of SLED treatment. Following this, patients received vancomycin, dosed to target a goal peak of 20-30 mcg/ml. A vancomycin peak level was drawn 1 hour after the end of the infusion. SLED treatment duration was at least 7 hours. Continuous data are reported as median (interquartile range) and categorical data as percentage. RESULTS: The vancomycin elimination rate and half-life were 0.051 hours (0.042-0.074 hours) and 13.6 hours (9.4-16.6 hours), respectively. SLED reduced vancomycin serum concentrations by 35.4% (31.5-43.8%), and vancomycin rebound was 9.8% (2.5-13.7%). The vancomycin dose administered post-SLED was 1000 mg (875-1125 mg). For 18 patients, the patient-specific volume of distribution was 0.88 L/kg (0.67-1.1 L/kg), vancomycin clearance was 3.5 L/hr (2.2-5.2 L/hr), and the area under the concentration-time curve during the study time period was 280.8 mg·hr/L (254.7-297.3 mg·hr/L). CONCLUSION: Vancomycin is significantly removed during SLED with little rebound in serum concentrations 4 hours after completion of SLED. Based on study findings, patients who are critically ill require additional vancomycin dosing after each SLED session to maintain therapeutic post-SLED vancomycin concentrations. Therapeutic drug monitoring of vancomycin is recommended during SLED.

Pre- and post-intervention study to assess the impact of a sedation protocol in critically ill surgical patients.

INTRODUCTION: Sedation and pain management for mechanically ventilated critically ill surgical patients pose many challenges for the intensivist. Even though daily interruption of sedatives and opioids is appropriate in medical intensive care unit (ICU) patients, it may not be feasible in the surgical patients with pain from surgical incision or trauma. Therefore we developed an analgesia/sedation based protocol for the surgical ICU population. METHODS: We performed a two-phase prospective observational control study. We evaluated a prescriber driven analgesia/sedation protocol (ASP) in a 12-bed surgical ICU. The pre-ASP group was sedated as usual (n = 100) and the post-ASP group was managed with the new ASP (n = 100). Each phase of the study lasted for 5 mo. Comparisons between the two groups were performed by χ(2) or Fisher's exact test for categorical variables and the Mann-Whitney test for nonparametric variables. A P value <0.05 was statistically significant. RESULTS: We found a significant reduction in the use of fentanyl (P < 0.001) and midazolam (P = 0.001). We achieved sedation goals of 86.8% in the post-ASP group compared to 74.4% in the pre-ASP (P < 0.001). Mean mechanical ventilations days in pre- and post-ASP group were 5.9 versus 3.8 (P = 0.033). CONCLUSION: In our cohort of critically ill surgery patients implementation of an ASP resulted in reduced use of continuously infused benzodiazepines and opioids, a decline in cumulative benzodiazepine and analgesic dosages, and a greater percentage of Richmond Agitation Sedation Scale scores at goal. We also showed reduced mechanical ventilation days.

Converting continuous insulin infusion to subcutaneous insulin glargine after cardiac surgery using percentage-based versus weight-based dosing: a pilot trial.

BACKGROUND: Most studies report using percentage of total daily insulin (TDI) for converting therapy from continuous insulin infusion to subcutaneous insulin in cardiac surgery patients. Few studies have evaluated the efficacy of using body weight to calculate the basal insulin dose. OBJECTIVE: To compare the efficacy and safety of dosing insulin glargine by weight versus percentage of TDI in cardiac surgery patients transitioning from continuous insulin infusion to subcutaneous insulin. METHODS: We conducted a prospective, randomized, open-label, pilot study. Study patients who had a preoperative weight less than 100 kg and were receiving at least 6 hours of a continuous insulin infusion were randomized to receive either 50% of their TDI requirement or 0.5 units/kg of glargine as a one-time dose 2 hours before stopping the continuous insulin infusion. All patients were administered subcutaneous corrective insulin. Blood glucose monitoring occurred before each meal, at bedtime, and with morning laboratory tests for 24 hours after administration of the glargine dose. RESULTS: A total of 200 blood glucose measurements were performed in each group. The percentage of blood glucose measurements in target range (80-140 mg/dL) was similar between the weight-based group and the percentage-based group (66% vs 64%, p = 0.75). Median blood glucose after transition was 120 mg/dL (interquartile range [IQR] 99-147) in the weight-based group compared to 127 mg/dL (IQR 107-149; p = 0.03) in the percentage-based group. The median glargine dose was higher in the weight-based group (41 units; IQR 36-44) than in the weight-based group (24 units; IQR 14-30, p < 0.001). The rate of hypoglycemia (blood glucose <60 mg/dL) was 2.5% in each group. CONCLUSIONS: In this small cohort, dosing insulin glargine by weight proved to be safe, but larger scale studies are needed before adopting weight-based dosing in this patient population.