Continuous Versus Intermittent Infusion of Vancomycin and the Risk of Acute Kidney Injury in Critically Ill Adults: A Systematic Review and Meta-Analysis.

OBJECTIVES: Critically ill patients routinely receive vancomycin as empiric antibiotic therapy. A continuous infusion administration strategy may be superior to intermittent infusion by minimizing peak concentrations and variability thereby optimizing safety. We performed a systematic review and meta-analysis to investigate the impact of vancomycin infusion strategy on acute kidney injury in critically ill adults. DATA SOURCES: A systematic search of MEDLINE, CINAHL, Web of Science, International Pharmaceutical Abstracts, and Google Scholar was undertaken. STUDY SELECTION: We included randomized controlled trials and observational studies evaluating acute kidney injury in critically ill adults comparing vancomycin administered by intermittent and continuous infusion. Secondary outcomes included mortality and pharmacokinetic target attainment. DATA EXTRACTION: Eleven studies were identified for analysis with baseline demographics, endpoints, protocol definitions, and outcomes extracted. DATA SYNTHESIS: When compared with intermittent infusion, continuous infusion was associated with a reduction in acute kidney injury in critically ill adults (odds ratio, 0.47; 95% CI, 0.34-0.65) and a 2.6 greater odds of pharmacokinetic target attainment (odds ratio, 2.63; 95% CI, 1.52-4.57). No difference in mortality was observed (odds ratio, 1.04; 95% CI, 0.80-1.35). CONCLUSIONS: When administered via a continuous infusion, vancomycin is associated with a 53% reduction in the odds of acute kidney injury and a 2.6-fold higher odds of pharmacokinetic target attainment when compared with intermittent infusion without influencing overall mortality.

Augmented Renal Clearance in Patients with Subarachnoid Hemorrhage.

BACKGROUND: Patients with subarachnoid hemorrhage (SAH) typically exhibit hyperdynamic cardiovascular hemodynamics, which may lead to increased medication clearance. The aims of this study were to evaluate the actual creatinine clearance (CrClA) in an aneurysmal SAH population and the effect of the development of cerebral vasospasm (CV) along with its treatment to better understand if this population exhibits augmented renal clearance (ARC). METHODS: This was a prospective, single-center study in a neurosciences ICU at a university hospital. A total of 20 patients were consented and provided a 24-h urine sample to measure the CrClA. If patients experienced CV, a 24-h urine collection was repeated during vasospasm treatment. CrClA was measured using a modified Jaffe assay. RESULTS: Among the 20 patients enrolled, the mean SAH CrClA was 325.93 ± 135.20 ml/min 1.73 m(2) and this differed significantly from the SAH estimated creatinine clearance (CrClE) 144.93 ± 42.82 ml/min 1.73 m(2) (p < 0.001). Four patients developed CV; the mean CV CrClA was 558.43 ± 356.12 ml/min 1.73 m(2) and there was no significant difference when compared to those patients' mean SAH CrClA (246.91 ± 84.14 ml/min 1.73 m(2), p = 0.16). CONCLUSIONS: ARC was present in 100 % of the patients with recent SAH enrolled. Although ARC remained present in the patients who experienced CV, their creatinine clearance was not significantly further augmented. Further work is needed to clarify the impact of such clearances on renally excreted medications and how the development and treatment of CV further augment these findings.

Hypoxemia associated with nimodipine in a patient with an aneurysmal subarachnoid hemorrhage.

PURPOSE: A case of probable nimodipine-induced hypoxemia in a patient undergoing treatment for aneurysmal subarachnoid hemorrhage (SAH) is reported. SUMMARY: A 62-year-old man hospitalized for SAH developed symptoms of respiratory distress on several occasions within days of initiation of nimodipine therapy (60 mg every four hours, with three doses withheld during intubation for intracranial surgery). Several hours after extubation (on hospital day 5), the patient had rapidly worsening tachypnea and declining arterial oxygen saturation (SPO2) despite increased oxygen delivery by mask, necessitating reintubation. When a nurse noted that the declines in SPO2 occurred soon after nimodipine administration, the patient's respiratory and hemodynamic functions were closely monitored after a single dose of nimodipine via nasogastic tube; the monitoring results supported the suspicion that nimodipine's vascular effects were a causal or contributory factor in the hypoxemia episodes. With subsequent fractionated dosing (30 mg every two hours), the patient completed the prescribed 21-day course of nimodipine therapy. Using the rating scale of Naranjo et al., this case was assigned a score of 7, indicating a probable pulmonary adverse reaction to nimodipine. As nimodipine is commonly used in cases of SAH to reduce delayed neurologic deficits due to persistent cerebral vasospasm, clinicians should be mindful of its potential hypoxemic effects in vulnerable patients. CONCLUSION: A patient with aneurysmal SAH developed hypoxemia associated with the administration of nimodipine. Hypoxemia is a known complication of treatment with other vasodilatory agents, particularly in patients who have concomitant pulmonary disease.