Lopez‐Ruiz, Arnaldo

Purpose of review Sarcopenia is a progressive generalized decline in skeletal muscle mass, strength, and function. This condition is highly prevalent in critically ill patients and is associated with poor outcomes in the ICU. In this review, we describe the use, evidence, and limitations of the most common validated imaging studies used to assess muscle mass in ICU, and we provide an overview of the benefits of using the sarcopenia index [(serum creatinine/serum cystatin C) × 100]) in the ICU. Recent findings Currently, the determination of muscle mass using anthropometric measurements and serum biomarkers is unreliable. Several new techniques, including a dual-energy X-ray absorptiometry, computed tomography scan, ultrasonography, and bioimpedance analysis, have been studied and validated for the diagnosis and prognosis of sarcopenia in the ICU. However, these techniques are often not accessible for the majority of critically ill patients. The sarcopenia index constitutes an accurate method to diagnose sarcopenia, predict ICU outcomes, and nutritional status in critically ill patients. Summary Diagnosis of sarcopenia has substantial implications in ICU patients. Choosing the correct test to identify patients who may need preventive or therapeutic support for this condition will favorably impact ICU outcomes.

AbstractBackgroundReliable and valid tools to screen for malnutrition in the intensive care unit (ICU) remain elusive. The sarcopenia index (SI) [(serum creatinine/serum cystatin C) × 100], could be an inexpensive, objective tool to predict malnutrition. We evaluated the SI as a screening tool for malnutrition in the ICU and compared it with the modified‐NUTRIC score.Materials and MethodsThis was a historical cohort study of ICU patients with stable kidney function admitted to Mayo Clinic ICUs between 2008 and 2015. Malnutrition was defined by the Subjective Global Assessment. Diagnostic performance was evaluated with the area under the receiver operating characteristic curve (AUC) and multivariable logistic regression.ResultsOf the 398 included patients, 181 (45%) had malnutrition, with 34 (9%) scored as severely malnourished. The SI was significantly lower in malnourished patients than in well‐nourished patients (64 ± 27 vs 72 ± 25; P = 0.002), and reductions in SI corresponded to increased malnutrition severity (P = 0.001). As a screening tool, the SI was an indicator of malnutrition risk (AUC 0.61) and performed slightly better than the more complex modified‐NUTRIC score (AUC = 0.57). SI cutoffs of 101 and 43 had >90% sensitivity and >90% specificity, respectively, for the prediction of malnutrition. Patients with a low SI (≤43) had a significantly higher risk of mortality (HR = 2.61, 95% CI 1.06–6.48, P = 0.038).ConclusionThe frequency of malnutrition was high in this critically ill population, and it was associated with a poor prognosis. The SI could be used to assess nutrition risk in ICU patients.

The objective of this study is to describe the pharmacokinetics of lacosamide in a critically ill adult during continuous venovenous hemofiltration (CVVH). A 78-year-old male developed sepsis and acute kidney injury following cardiac surgery. He was initially treated with intermittent hemodialysis but developed nonconvulsive status epilepticus at the end of the first session and was subsequently initiated on CVVH. In addition to lorazepam boluses, levetiracetam, and midazolam infusion, he was loaded with lacosamide 400 mg intravenously and started on 200 mg intravenously twice daily as maintenance therapy. Noncompartmental modeling of lacosamide pharmacokinetics revealed significant extracorporeal removal, a volume of distribution of 0.69 L/kg, elimination half-life of 13.6 hours, and peak and trough concentrations of 7.4 and 3.7 mg/L, respectively (goal trough, 5-10 mg/L). We found significant extracorporeal removal of serum lacosamide during CVVH, which was higher than previously reported. This led to subtherapeutic concentrations and decreased overall antiepileptic drug exposure. The relationship between serum lacosamide concentrations and clinical efficacy is not well understood; thus, therapeutic drug monitoring is not routinely recommended. Yet, we demonstrated that measuring serum lacosamide concentrations in the critically ill population during continuous renal replacement therapy may be useful to individualize dosing programs. Further pharmacokinetic studies of lacosamide may be necessary to generate widespread dosing recommendations.

Renal ischemia-reperfusion (I/R) in male rats causes reductions in plasma testosterone, and infusion of testosterone 3 h postreperfusion is protective. We tested the hypotheses that acute high doses of testosterone promote renal injury after I/R, and that acute low-dose testosterone is protective by the following: 1) increasing renal IL-10 and reducing TNF-α; 2) its effects on nitric oxide; and 3) reducing intrarenal T-cell infiltration. Rats were subjected to renal I/R, followed by intravenous infusion of vehicle or testosterone (20, 50, or 100 μg/kg) 3 h postreperfusion. Low-dose testosterone (20 μg/kg) reduced plasma creatinine, increased nitrate/nitrite excretion, increased intrarenal IL-10, and reduced intrarenal TNF-α, whereas 50 μg/kg testosterone failed to reduce plasma creatinine, increased IL-10, but failed to reduce TNF-α. A higher dose of testosterone (100 mg/kg) not only failed to reduce plasma creatinine, but significantly increased both IL-10 and TNF-α compared with other groups. Low-dose nitro-l-arginine methyl ester (1 mg·kg−1·day−1), given 2 days before I/R, prevented low-dose testosterone (20 μg/kg) from protecting against I/R injury, and was associated with lack of increase in intrarenal IL-10. Intrarenal CD4+ and CD8+ T cells were significantly increased with I/R, but were attenuated with low-dose testosterone, as were effector T helper 17 cells. The present studies suggest that acute, low-dose testosterone is protective against I/R AKI in males due to its effects on inflammation by reducing renal T-cell infiltration and by shifting the balance to favor anti-inflammatory cytokine production rather than proinflammatory cytokines.