Enhanced Renal Clearance in Patients With Hemorrhagic Stroke

Augmented Renal Clearance: Prevalence, Risk Factors and Underlying Mechanism in Critically Ill Patients with Subarachnoid Hemorrhage

BACKGROUND

Augmented renal clearance (ARC) is an increase in the measured creatinine clearance (CLCR), the cause of which remains poorly understood. ARC may be associated with drug underdosing and appears to be more frequent in patients with brain damage, such as subarachnoid hemorrhage (SaH), although the incidence of ARC remains poorly understood. The aim of this study was to investigate the prevalence of ARC in patients with SaH in a neurointensive care unit (neuro-ICU) and to identify factors associated with ARC.

METHODS

All consecutive patients hospitalized in the neuro-ICU of Bordeaux University Hospital between June 2018 and June 2019 for SaH treatment were retrospectively included. CLCR was measured daily via 24-h urine collection. ARC was defined as a CLCR ≥ 130 mL/min/1.73 m2. The effects of different covariates on the time course of CLCR were investigated using a linear mixed model.

RESULTS

Of the 205 included study participants, 168 developed ARC during their neuro-ICU stay; the estimated ARC prevalence was 82% (95% confidence interval 76-87) with a median of 4 days (range 3-6 days) after hemorrhage; ARC persisted for a median of 5 days (range 2-8 days). Patients with ARC were younger and had a lower BMI and lower mortality rate. In multivariate analysis, younger patients with a higher mean arterial pressure, no history of hypertension, and greater nitrogen loss were more likely to have ARC.

CONCLUSIONS

Augmented renal clearance is very common in critically ill patients with SaH, persists over time, and seems to lack specific risk factors. Daily CLCR measurements could be essential.

Stroke-Induced Renal Dysfunction: Underlying Mechanisms and Challenges of the Brain-Kidney Axis

Stroke, a major neurological disorder and a leading cause of disability and death, often inflicts damage upon other organs, particularly the kidneys. While chronic kidney disease (CKD) has long been established as a significant risk factor for cerebrovascular disease, stroke can induce renal dysfunction, manifesting as acute kidney injury (AKI) or CKD. Mounting clinical and basic research evidence supports the existence of a bidirectional brain-kidney crosstalk following stroke, implicating specific mechanisms and pathways in stroke-related renal dysfunction. This review analyzes pertinent experimental studies, elucidating the underlying mechanisms of this cerebro-renal interaction following stroke. Additionally, we summarize the current landscape of clinical research investigating brain-kidney interplay and discuss potential challenges in the future. By enhancing our understanding of the scientific underpinnings of brain-kidney crosstalk, this review paves the way for improved treatment strategies and outcomes for stroke patients. Recognizing the intricate interplay between the brain and kidneys after stroke holds profound clinical implications.

Systemic tolerance of intravenous milrinone administration for cerebral vasospasm secondary to non-traumatic subarachnoid hemorrhage

PURPOSE

Delayed cerebral ischemia (DCI) is a severe subarachnoid hemorrhage (SAH) complication, closely related to cerebral vasospasm (CVS). CVS treatment frequently comprises intravenous milrinone, an inotropic and vasodilatory drug. Our objective is to describe milrinone's hemodynamic, respiratory and renal effects when administrated as treatment for CVS.

METHODS

Retrospective single-center observational study of patients receiving intravenous milrinone for CVS with systemic hemodynamics, oxygenation, renal disorders monitoring. We described these parameters' evolution before and after milrinone initiation (day - 1, baseline, day 1 and day 2), studied treatment cessation causes and assessed neurological outcome at 3-6 months.

RESULTS

Ninety-one patients were included. Milrinone initiation led to cardiac output increase (4.5 L/min [3.4-5.2] at baseline vs 6.6 L/min [5.2-7.7] at day 2, p < 0.001), Mean Arterial Pressure decrease (101 mmHg [94-110] at baseline vs 95 mmHg [85-102] at day 2, p = 0.001) norepinephrine treatment requirement increase (32% of patients before milrinone start vs 58% at day 1, p = 0.002) and slight PaO2/FiO2 ratio deterioration (401 [333-406] at baseline vs 348 [307-357] at day 2, p = 0.016). Milrinone was interrupted in 8% of patients. 55% had a favorable outcome.

CONCLUSION

Intravenous milrinone for CVS treatment seems associated with significant impact on systemic hemodynamics leading sometimes to treatment discontinuation.

Predicting ICU readmission risks in intracerebral hemorrhage patients: Insights from machine learning models using MIMIC databases

BACKGROUND

Intracerebral hemorrhage (ICH) is a stroke subtype characterized by high mortality and complex post-event complications. Research has extensively covered the acute phase of ICH; however, ICU readmission determinants remain less explored. Utilizing the MIMIC-III and MIMIC-IV databases, this investigation develops machine learning (ML) models to anticipate ICU readmissions in ICH patients.

METHODS

Retrospective data from 2242 ICH patients were evaluated using ICD-9 codes. Recursive feature elimination with cross-validation (RFECV) discerned significant predictors of ICU readmissions. Four ML models-AdaBoost, RandomForest, LightGBM, and XGBoost-underwent development and rigorous validation. SHapley Additive exPlanations (SHAP) elucidated the effect of distinct features on model outcomes.

RESULTS

ICU readmission rates were 9.6% for MIMIC-III and 10.6% for MIMIC-IV. The LightGBM model, with an AUC of 0.736 (95% CI: 0.668-0.801), surpassed other models in validation datasets. SHAP analysis revealed hydrocephalus, sex, neutrophils, Glasgow Coma Scale (GCS), specific oxygen saturation (SpO2) levels, and creatinine as significant predictors of readmission.

CONCLUSION

The LightGBM model demonstrates considerable potential in predicting ICU readmissions for ICH patients, highlighting the importance of certain clinical predictors. This research contributes to optimizing patient care and ICU resource management. Further prospective studies are warranted to corroborate and enhance these predictive insights for clinical utilization.

Enhanced renal clearance impacts levetiracetam concentrations in patients with traumatic brain injury with and without augmented renal clearance

BACKGROUND

The purpose of this study was to examine the impact of ARC on levetiracetam concentrations during the first week following acute TBI. The hypothesis was levetiracetam concentrations are significantly lower in TBI patients with augmented renal clearance (ARC) compared to those with normal renal clearance.

METHODS

This is a prospective cohort pharmacokinetic study of adults with moderate to severe TBI treated with levetiracetam during the first week after injury. Serial blood collections were performed daily for analysis of levetiracetam, cystatin C, and 12-hr creatinine clearance (CrCl) determinations. Patients were divided into two cohorts: with (CrCl ≥130 ml/min/1.73 m2) and without ARC.

RESULTS

Twenty-two patients with moderate to severe TBI were included. The population consisted primarily of young male patients with severe TBI (mean age 40 years old, 68% male, median admission GCS 4). Each received levetiracetam 1000 mg IV every 12 h for the study period. ARC was present in 77.3% of patients, with significantly lower levetiracetam concentrations in ARC patients and below the conservative therapeutic range (< 6mcg/mL) for all study days. In patients without ARC, the serum concentrations were also below the expected range on all but two study days (Days 4 and 5). Four of the 22 (18.2%) patients exhibited seizure activity during the study period (two of these patients exhibited ARC). Cystatin C concentrations were significantly lower in patients with ARC, though the mean for all patients was within the typical normal range.

CONCLUSIONS

ARC has a high prevalence in patients with moderate to severe TBI. Levetiracetam concentrations after standard dosing were low in all TBI patients, but significantly lower in patients with ARC. This study highlights the need to consider personalized drug dosing in TBI patients irrespective of the presence of ARC.

CLINICAL TRIAL REGISTRATION

This study was registered at cliicaltrials.gov (NCT02437838) Registered on 08/05/2015, https://clinicaltrials.gov/ct2/show/NCT02437838 .

Augmented Renal Clearance in the Hematology and Oncology Populations: A Scoping Review for Pharmacists

INTRODUCTION

Until recently, interest in renal function has focused on impairment to limit drug toxicity and increase medication safety. Augmented renal clearance (ARC) has been increasingly studied in multiple patient populations, including oncology, and could lead to decreased drug efficacy from faster elimination resulting in subtherapeutic concentrations. This scoping review sought to summarize ARC literature in cancer and identify areas of research to better inform pharmacy practitioners.

DATA SOURCES

Electronic databases were searched for English articles related to augmented/enhanced renal function/clearance following a framework for scoping reviews.

DATA SYNTHESIS

Fourteen articles were analyzed, divided according to article objective: descriptive studies or ARC's impact on pharmacokinetics/pharmacodynamics. ARC was most defined as creatinine clearance >130 mL/min/1.73 m2, reported in 10%-100% of patients. Febrile neutropenia in adult and pediatric patients, and age <50-65 years, hematologic malignancy, and lower serum creatinine in adult patients were notable risk factors for ARC. The impact of ARC has only been evaluated with antimicrobial agents consistently resulting in lower than anticipated trough levels. Identified gaps include: elucidation of ARC's mechanism and associated biomarkers, an inclusive ARC definition for relative renal enhancement, and study of additional drug classes to ascertain the breadth of ARC impact on drug therapy.

CONCLUSIONS

ARC is proving to be a frequent phenomenon in patients with cancer which pharmacists could play a vital role. Further research is needed to better understand the impact of ARC in patient care and a potential need to stage ARC based on degree of renal enhancement to establish specific drug dosing recommendations.

Performance of different body weights in the Cockcroft-Gault equation in critically ill patients with and without augmented renal clearance: A multicenter cohort

STUDY OBJECTIVE

The primary objective was to evaluate the performance of the Cockcroft-Gault (CG) equation with different body weights (BWs) compared to a measured creatinine clearance (mCrCl) in an intensive care unit (ICU) population with and without augmented renal clearance (ARC).

DESIGN

Multicenter, retrospective cohort.

SETTING

Two ICUs in the United States and four ICUs from a previous international observational analysis.

PATIENTS

Adult ICU patients admitted from January 1, 2010 to July 30, 2020 with at least one mCrCl collected within the initial 10 days of hospitalization were eligible for inclusion.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was the performance of the CG equation in ARC (mCrCl≥130 ml/min/1.73 m2 ) and non-ARC (mCrCl<130 ml/min/1.73 m2 ) patients. Correlation was analyzed by Pearson's correlation coefficient, bias by mean difference, and accuracy by the percentage of patients within 30% of the mCrCl. A total of 383 patients were included, which provided 1708 mCrCl values. The majority were male (n = 239, 62%), median age of 55 years [IQR 40-65] with a surgical diagnosis (n = 239, 77%). ARC was identified in 229 (60%) patients. The ARC group had lower Scr values (0.6 [0.5-0.7] vs. 0.7 [0.6-0.9] mg/dl, p < 0.001) and higher mCrCl (172.8 (SD 39.1) vs. 89.9 mL/min/1.73 m2 (SD 25.4), p < 0.001) compared with the non-ARC group, respectively. Among non-ARC patients there was a moderate correlation (r = 0.33-0.39), moderate accuracy (range 48-58%), and low bias (range of -12.9 to 17.1) among the different BW estimations with the adjusted BW having the better performance. Among ARC patients there was low correlation (r = 0.24-0.28), low to moderate accuracy (range 38-70%), and high bias (range of -58.5 to -21.6).

CONCLUSIONS

The CG-adjusted BW had the best performance in the non-ARC patients, while CG performed poorly with any BW in ARC patients. Although the CG equation remains the standard equation for estimating CrCl in the ICU setting, a new, validated equation is needed for patients with ARC.

Augmented Renal Clearance in Patients with Acute Ischemic Stroke: A Prospective Observational Study

BACKGROUND

Augmented renal clearance (ARC) is a phenomenon that has been demonstrated in many subsets of critically ill patients and is characterized by a creatinine clearance (CrCl) > 130 mL/min. Prior research has examined ARC prevalence in the presence of sepsis, traumatic brain injury, subarachnoid hemorrhage, and intracranial hemorrhage. However, to our knowledge, no studies have examined whether this phenomenon occurs in patients suffering from an acute ischemic stroke (AIS). The objective of this study was to evaluate whether patients experiencing an AIS exhibit ARC, identify potential contributing factors, and examine the precision of current renal clearance estimation methods in patients with AIS experiencing ARC.

METHODS

This was a single-center prospective observational study conducted in adult patients admitted to a neurocritical intensive care unit (ICU) at a community hospital. Once consent was gained, patients with an admitting diagnosis of an AIS underwent a 24-h urine collection to assess measured CrCl. The primary end point assessed for ARC, defined as a measured CrCl > 130 mL/min. The secondary end point evaluated length of stay in the neurocritical ICU.

RESULTS

Twenty-eight patients met enrollment criteria, and data was analyzed for 20 patients. ARC was present in 35% of enrolled patients. Mathematical estimations of renal function were inadequate in detecting ARC manifestation. Patients experiencing ARC were associated with nonsignificantly shorter ICU length of stay.

CONCLUSIONS

ARC appears to manifest in patients with AIS inconsistently. Patients experiencing ARC were associated with nonsignificantly shorter ICU length of stay.

Comparison of machine learning and logistic regression as predictive models for adverse maternal and neonatal outcomes of preeclampsia: A retrospective study

Introduction

Preeclampsia, one of the leading causes of maternal and fetal morbidity and mortality, demands accurate predictive models for the lack of effective treatment. Predictive models based on machine learning algorithms demonstrate promising potential, while there is a controversial discussion about whether machine learning methods should be recommended preferably, compared to traditional statistical models.

Methods

We employed both logistic regression and six machine learning methods as binary predictive models for a dataset containing 733 women diagnosed with preeclampsia. Participants were grouped by four different pregnancy outcomes. After the imputation of missing values, statistical description and comparison were conducted preliminarily to explore the characteristics of documented 73 variables. Sequentially, correlation analysis and feature selection were performed as preprocessing steps to filter contributing variables for developing models. The models were evaluated by multiple criteria.

Results

We first figured out that the influential variables screened by preprocessing steps did not overlap with those determined by statistical differences. Secondly, the most accurate imputation method is K-Nearest Neighbor, and the imputation process did not affect the performance of the developed models much. Finally, the performance of models was investigated. The random forest classifier, multi-layer perceptron, and support vector machine demonstrated better discriminative power for prediction evaluated by the area under the receiver operating characteristic curve, while the decision tree classifier, random forest, and logistic regression yielded better calibration ability verified, as by the calibration curve.

Conclusion

Machine learning algorithms can accomplish prediction modeling and demonstrate superior discrimination, while Logistic Regression can be calibrated well. Statistical analysis and machine learning are two scientific domains sharing similar themes. The predictive abilities of such developed models vary according to the characteristics of datasets, which still need larger sample sizes and more influential predictors to accumulate evidence.

Augmented renal clearance in the ICU: estimation, incidence, risk factors and consequences-a retrospective observational study

Background

Augmented renal clearance (ARC) remains poorly evaluated in ICU. The objective of this study is to provide a full description of ARC in ICU including prevalence, evolution profile, risk factors and outcomes.

Methods

This was a retrospective, single-center, observational study. All the patients older than 18 years admitted for the first time in Medical ICU, Bichat, University Hospital, APHP, France, between January 1, 2017, and November 31, 2020 and included into the Outcomerea database with an ICU length of stay longer than 72 h were included. Patients with chronic kidney disease were excluded. Glomerular filtration rate was estimated each day during ICU stay using the measured creatinine renal clearance (CrCl). Augmented renal clearance (ARC) was defined as a 24 h CrCl greater than 130 ml/min/m².

Results

312 patients were included, with a median age of 62.7 years [51.4; 71.8], 106(31.9%) had chronic cardiovascular disease. The main reason for admission was acute respiratory failure (184(59%)) and 196(62.8%) patients had SARS-COV2. The median value for SAPS II score was 32[24; 42.5]; 146(44%) and 154(46.4%) patients were under vasopressors and invasive mechanical ventilation, respectively. The overall prevalence of ARC was 24.6% with a peak prevalence on Day 5 of ICU stay. The risk factors for the occurrence of ARC were young age and absence of cardiovascular comorbidities. The persistence of ARC during more than 10% of the time spent in ICU was significantly associated with a lower risk of death at Day 30.

Conclusion

ARC is a frequent phenomenon in the ICU with an increased incidence during the first week of ICU stay. Further studies are needed to assess its impact on patient prognosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13613-022-01058-w.

Augmented Renal Clearance in Severe Infections-An Important Consideration in Vancomycin Dosing: A Narrative Review

Vancomycin is a hydrophilic antibiotic widely used in severe infections, including bacteremia and central nervous system (CNS) infections caused by Gram-positive bacteria such as methicillin-resistant Staphylococcus aureus (MRSA), coagulase-negative staphylococci and enterococci. Appropriate antimicrobial dosage regimens can help achieve the target exposure and improve clinical outcomes. However, vancomycin exposure in serum and cerebrospinal fluid (CSF) is challenging to predict due to rapidly changing pathophysiological processes and patient-specific factors. Vancomycin concentrations may be decreased for peripheral infections due to augmented renal clearance (ARC) and increased distribution caused by systemic inflammatory response syndrome (SIRS), increased capillary permeability, and aggressive fluid resuscitation. Additionally, few studies on vancomycin’s pharmacokinetics (PK) in CSF for CNS infections. The relationship between exposure and clinical response is unclear, challenging for adequate antimicrobial therapy. Accurate prediction of vancomycin pharmacokinetics/pharmacodynamics (PK/PD) in patients with high interindividual variation is critical to increase the likelihood of achieving therapeutic targets. In this review, we describe the interaction between ARC and vancomycin PK/PD, patient-specific factors that influence the achievement of target exposure, and recent advances in optimizing vancomycin dosing schedules for severe infective patients with ARC.

Intravenous Brivaracetam in the Management of Acute Seizures in the Hospital Setting: A Scoping Review

Background

Clinical considerations for drug treatment of acute seizures involve variables such as safety, tolerability, drug-drug interactions, dosage, route of administration, and alterations in pharmacokinetics because of critical illness. Therapy options that are easily and quickly administered without dilution, well tolerated, and effective are needed for the treatment of acute seizures. The objective of this review is to focus on the clinical considerations relating to the use of intravenous brivaracetam (IV BRV) for the treatment of acute seizures in the hospital, focusing on critically ill patients.

Methods

This was a scoping literature review of PubMed from inception to April 13, 2021, and search of the American Academy of Neurology (AAN) 2021 Annual Meeting website for English language publications/conference abstracts reporting the results of IV BRV use in hospitalized patients, particularly in the critical care setting. Outcomes of interest relating to the clinical pharmacology, safety, tolerability, efficacy, and effectiveness of IV BRV were reviewed and are discussed.

Results

Twelve studies were included for analysis. One study showed that plasma concentrations of IV BRV 15 min after the first dose were similar between patients receiving IV BRV as bolus or infusion. IV BRV was generally well tolerated in patients with acute seizures in the hospital setting, with a low incidence of individual TEAEs classified as behavioral disorders. IV BRV demonstrated efficacy and effectiveness and had a rapid onset, with clinical and electrophysiological improvement in seizures observed within minutes. Although outside of the approved label, findings from several studies suggest that IV BRV reduces seizures and is generally well tolerated in patients with status epilepticus.

Conclusions

IV BRV shows effectiveness, and is generally well tolerated in the management of acute seizures in hospitalized patients where rapid administration is needed, representing a clinically relevant antiseizure medication for potential use in the critical care setting.

Prevalence and Risk Factors of Augmented Renal Clearance: A Systematic Review and Meta-Analysis

Kidney function assessment in the critically ill overlooks the possibility for hyperfunctioning kidneys, known as augmented renal clearance (ARC), which could contribute to therapeutic failures in the intensive care unit (ICU). The aim of this research is to conduct a systematic review and meta-analysis of prevalence and risk factors of ARC in the critically ill. MEDLINE, Embase, Cochrane Library, CINAHL, Scopus, ProQuest Dissertations and Theses Global databases were searched on 27 October 2020. We included studies conducted in critically ill adults who reported the prevalence and/or risk factors of ARC. We evaluated study quality using the Joanna Briggs Institute appraisal tool. Case reports, reviews, editorials and commentaries were excluded. We generated a random-effects meta-analytic model using the inverse variance method and visualized the pooled estimates using forest plots. Seventy studies were included. The pooled prevalence (95% CI) was 39% (34.9–43.3). Prevalence for neuro, trauma, mixed and sepsis ICUs were 74 (55–87), 58 (48–67), 36 (31–41) and 33 (21–48), respectively. Age, male sex and trauma were associated with ARC with pooled OR (95% CI) of 0.95 (0.93–0.96), 2.36 (1.28–4.36), 2.60 (1.21–5.58), respectively. Limitations included variations in ARC definition, inclusion and exclusion criteria and studies design. In conclusion, ARC is prevalent in critically ill patients, especially those in the neurocritical care and trauma ICU population. Young age, male sex and trauma are risk factors for ARC in those with apparently normal renal function. Further research on optimal dosing of drugs in the setting of ARC is warranted. (Prospero registration: CRD42021246417).

Cystatin C and/or creatinine-based estimated glomerular filtration rate for prediction of vancomycin clearance in long-stay critically ill patients with persistent inflammation, immunosuppression and catabolism syndrome (PICS): a population pharmacokinetics analysis

Persistent inflammation, immunosuppression and catabolism syndrome (PICS) in critically ill patients are associated with unreliable creatinine (Cr)-based estimated glomerular filtration rate (eGFR) and alteration in vancomycin clearance (CL) due to ongoing muscle wasting and renal dysfunction (RD). Currently, cystatin C (Cys) is of great interest for eGFR due to its muscle independence. Patients receiving intravenous vancomycin with trough concentration monitoring after intensive care unit stay ≥ 14 days were retrospectively enrolled. Those with C-reactive protein > 30.0 mg/L, lymphocytes count < 0.80 × 10⁹, albumin < 30 mg/L and weight loss > 10% were diagnosed with PICS. Impact of PICS on vancomycin trough achievement was analyzed. Plasma Cys and Cr levels with their eGFRs in RD were compared in patients with and without PICS. Furthermore, the performance of eGFRs in predicting vancomycin CL was quantificationally evaluated by population pharmacokinetics (PPK) analysis using the Phoenix NLME software. Of 69 enrolled patients, 32 (46.4%) were PICS. PICS was predictive of Cr-guided vancomycin supratherapeutic trough concentrations (OR = 5.26, P = 0.013). Significant elevation of Cys, not of Cr, was observed in patients with PICS suffering from RD (P = 0.022), causing substantial differences among eGFRs. Fifty-two and 17 patients were enrolled for the modeling group and validation group, respectively. A one-compartment PPK model with first-order elimination adequately described the data of 126 C_trough. Prediction of vancomycin CL with Cys and Cr-based eGFR (CKD-EPI_cys-cr) significantly reduced the interindividual variability of CL (from 75.6 to 28.5%). External validation with 34 C_trough showed the robustness and accuracy of this model. This study showed the negative impact of PICS on Cr-guided vancomycin trough achievement. PPK model with CKD-EPI_cys-cr can be used to optimize vancomycin dosage in patients with PICS.

Intravenous Milrinone for Cerebral Vasospasm in Subarachnoid Hemorrhage: The MILRISPASM Controlled Before-After Study

BACKGROUND

Intravenous (IV) milrinone, in combination with induced hypertension, has been proposed as a treatment option for cerebral vasospasm after aneurysmal subarachnoid hemorrhage (aSAH). However, data on its safety and efficacy are scarce.

METHODS

This was a controlled observational study conducted in an academic hospital with prospectively and retrospectively collected data. Consecutive patients with cerebral vasospasm following aSAH and treated with both IV milrinone (0.5 µg/kg/min^-1, as part of a strict protocol) and induced hypertension were compared with a historical control group receiving hypertension alone. Multivariable analyses aimed at minimizing potential biases. We assessed (1) 6-month functional disability (defined as a score between 2 and 6 on the modified Rankin Scale) and vasospasm-related brain infarction, (2) the rate of first-line or rescue endovascular angioplasty for vasospasm, and (3) immediate tolerance to IV milrinone.

RESULTS

Ninety-four patients were included (41 and 53 in the IV milrinone and the control group, respectively). IV milrinone infusion was independently associated with a lower likelihood of 6-month functional disability (adjusted odds ratio [aOR] = 0.28, 95% confidence interval [CI] = 0.10-0.77]) and vasospasm-related brain infarction (aOR = 0.19, 95% CI 0.04-0.94). Endovascular angioplasty was less frequent in the IV milrinone group (6 [15%] vs. 28 [53%] patients, p = 0.0001, aOR = 0.12, 95% CI 0.04-0.38). IV milrinone (median duration of infusion, 5 [2-8] days) was prematurely discontinued owing to poor tolerance in 12 patients, mostly (n = 10) for "non/hardly-attained induced hypertension" (mean arterial blood pressure < 100 mmHg despite 1.5 µg/kg/min^-1 of norepinephrine). However, this event was similarly observed in IV milrinone and control patients (n = 10 [24%] vs. n = 11 [21%], respectively, p = 0.68). IV milrinone was associated with a higher incidence of polyuria (IV milrinone patients had creatinine clearance of 191 [153-238] ml/min^-1) and hyponatremia or hypokalemia, whereas arrhythmia, myocardial ischemia, and thrombocytopenia were infrequent.

CONCLUSIONS

Despite its premature discontinuation in 29% of patients as a result of its poor tolerance, IV milrinone was associated with a lower rate of endovascular angioplasty and a positive impact on long-term neurological and radiological outcomes. These preliminary findings encourage the conduction of confirmatory randomized trials.

Scoping review of augmented renal clearance in critically ill pediatric patients

Augmented renal clearance (ARC), a phenomenon of enhanced elimination of renal solutes, has been described in adult critically ill patients, but little is known about the phenomenon in children. The aim of this scoping review was to gather and summarize all evidence on ARC in pediatric patients to examine its breadth and depth including prevalence, risk factors, and pharmacokinetic alterations and identify any gaps for further areas of inquiry. PubMed, Embase, and Web of Science were searched for titles, abstracts, or keywords that focused on ARC. Non-English studies, reviews, and nonhuman studies were excluded. Reporting followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses for Scoping Reviews (PRISMA-ScR) guidelines. Data were extracted on article type, study details, patient population, ARC definition and prevalence, methods of renal function assessment, and study results. A total of 215 citations were found with 25 citations meeting the criteria for inclusion in pediatrics (2102 total patients); the majority of studies (84%) focused on pharmacokinetics (PK) of antimicrobial agents. The median/mean age range was 1.25-12 years. There were a total of 10 different definitions of ARC. The prevalence of ARC ranged from 7.8% to 78%. The most common method for documenting creatinine clearance (CrCl) was the modified Schwartz equation (64%). Only 20% of studies reported risk factors for ARC including low serum creatinine, increasing age, febrile neutropenia, male, septic shock, and treatment with antibiotics. Glycopeptide antimicrobials were the most evaluated class (42.9%) among the 21 antimicrobial drug studies. All studies reported increased drug clearance and/or poor probability of achieving target concentrations of the agents studied. ARC showed variable prevalence in pediatric patients likely due to the lack of a standard definition and many studies not considering age-related changes in CrCl with pediatric intensive care unit (PICU) patients. ARC was shown to impact PK of antibiotics commonly administered to pediatric patients, which may necessitate changes in standard dosing regimens.

Evaluation of the Accuracy of Standard Renal Function Equations in Critically Ill Patients with Subarachnoid Hemorrhage

BACKGROUND

Obtaining an accurate estimation of renal function is germane to optimizing care in critically ill patients. However, there is no consensus on the most accurate renal function assessment to utilize in this patient population, particularly in aneurysmal subarachnoid hemorrhage (aSAH) patients. Thus, the objective of this observational study was to determine the comparability of renal function equations to body surface area (BSA)-adjusted 8-h creatinine clearance (CrCl) in aSAH patients.

METHODS

A PubMed search investigated the applicability of various renal function equations in critically ill patient populations. A subset of these equations was compared to BSA-adjusted 8-h CrCl from a previous study with aSAH patients with no evidence of renal dysfunction (admission serum creatinine < 1.5 mg/dL) and no history of chronic kidney disease. Area-under-the-curve (AUC) calculations were completed using serial laboratory measurements to validate preliminary findings.

RESULTS

A total of 14 renal function equations were identified with seven carried forward for further analysis based upon a priori criteria. Seven equations were excluded for various reasons, including lack of available clinical data, redundancy with other equations, and dissimilar patient populations to this study. When directly compared to the BSA-adjusted 8-h CrCl, only the Cockcroft-Gault and BSA-adjusted Cockcroft-Gault equations were not statistically significantly different (P = 0.0886 and P = 0.4805, respectively); all other equations were statistically significantly different (P < 0.0001). Additionally, only 52% and 44% of patients had average values within 20% of the BSA-adjusted 8-h CrCl using the Cockcroft-Gault and BSA-adjusted Cockcroft-Gault equations, respectively. Finally, the AUC calculations corroborated the preliminary findings with similar results in statistical testing for the Cockcroft-Gault and BSA-adjusted Cockcroft-Gault (P = 0.6300 and P = 0.1513, respectively).

CONCLUSIONS

The Cockcroft-Gault equation may be the best renal function equation to assess in critically ill patients diagnosed with aSAH. However, accuracy and consistency in assessing renal function when compared to the BSA-adjusted 8-h CrCl were lacking. Thus, this study suggests the BSA-adjusted 8-h CrCl may be the most appropriate assessment of renal function in patients with aSAH.

Augmented Renal Clearance Following Traumatic Injury in Critically Ill Patients Requiring Nutrition Therapy

The intent of this study was to ascertain the prevalence of augmented renal clearance (ARC) in patients with traumatic injuries who require nutrition therapy and identify factors associated with ARC. Adult patients admitted to the trauma intensive care unit from January 2015 to September 2016 who received enteral or parenteral nutrition therapy and had a 24 h urine collection within 4 to 14 days after injury were retrospectively evaluated. Patients with a serum creatinine concentration > 1.5 mg/dL, required dialysis, or had an incomplete urine collection were excluded. ARC was defined as a measured creatinine clearance > 149 mL/min/1.73 m². Two hundred and three patients were evaluated. One hundred and two (50%) exhibited ARC. A greater proportion of patients with ARC were male (86% vs. 67%; p = 0.004), had traumatic brain injury (33% vs. 9%; p = 0.001), a higher injury severity score (30 ± 11 vs. 26 ± 12; p = 0.015), were younger (36 ± 15 vs. 54 ± 17 years; p = 0.001), had a lower serum creatinine concentration (0.7 ± 2 vs. 0.9 ± 0.2 mg/dL; p = 0.001) and were more catabolic (nitrogen balance of −10.8 ± 13.0 vs. −6.2 ± 9.2 g/d; p = 0.004). The multivariate analysis revealed African American race and protein intake were also associated with ARC. Half of critically ill patients with traumatic injuries experience ARC. Patients with multiple risk factors for ARC should be closely evaluated for dosing of renally-eliminated electrolytes, nutrients, and medications.

Prognostic Nomogram of Predictors for Shunt-Dependent Hydrocephalus in Patients with Aneurysmal Subarachnoid Hemorrhage Receiving External Ventricular Drain Insertion: A Single-Center Experience and Narrative Review

OBJECTIVE

This study aimed to create a prediction model with a radiographic score, serum, and cerebrospinal fluid (CSF) values for the occurrence of shunt-dependent hydrocephalus (SDHC) in patients with aneurysmal subarachnoid hemorrhage (aSAH) and to review and analyze literature related to the prediction of the development of SDHC.

METHODS

Sixty-three patients with aSAH who underwent external ventricular drain insertion were included and separated into 2 subgroups: non-SDHC and SDHC. Patient characteristics, computed tomography scoring system, and serum and CSF parameters were collected. Multivariate logistic regression was conducted to illustrate a nomogram for determining the predictors of SDHC. Furthermore, we sorted and summarized previous meta-analyses for predictors of SDHC.

RESULTS

The SDHC group had 42 cases. Stepwise logistic regression analysis revealed 3 independent predictive factors associated with a higher modified Graeb (mGraeb) score, lower level of estimated glomerular filtration rate group, and lower level of CSF glucose. The nomogram, based on these 3 factors, was presented with significant predictive performance (area under curve = 0.895) for SDHC development, compared with other scoring systems (AUC = 0.764-0.885). In addition, a forest plot was generated to present the 12 statistically significant predictors and odds ratio for correlations with the development of SDHC.

CONCLUSIONS

First, the development of a nomogram with combined significant factors had a good performance in estimating the risk of SDHC in primary patient evaluation and assisted in clinical decision making. Second, a narrative review, presented with a forest plot, provided the current published data on predicting SDHC.

Time courses of urinary creatinine excretion, measured creatinine clearance and estimated glomerular filtration rate over 30 days of ICU admission

PURPOSE

Baseline urinary creatinine excretion (UCE) is associated with ICU outcome, but its time course is not known.

MATERIALS AND METHODS

We determined changes in UCE, plasma creatinine, measured creatinine clearance (mCC) and estimated glomerular filtration (eGFR) in patients with an ICU-stay ≥30d without acute kidney injury stage 3. The Cockcroft-Gault, MDRD (modification of diet in renal disease) and CKD-EPI (chronic kidney disease epidemiology collaboration) equations were used.

RESULTS

In 248 patients with 5143 UCEs hospital mortality was 24%. Over 30d, UCE absolutely decreased in male survivors and non-survivors and female survivors and nonsurvivors by 0.19, 0.16, 0.10 and 0.05 mmol/d/d (all P < 0.001). Relative decreases in UCE were similar in all four groups: 1.3, 1.4, 1.2 and 0.9%/d respectively. Over 30d, mCC remained unchanged, but eGFR rose by 31% (CKD-EPI) and 73% (MDRD) and creatinine clearance estimated by Cockcroft-Gault by 59% (all P < 0.001).

CONCLUSIONS

Over 1 month of ICU stay, UCE declined by ≥1%/d which may correspond to an equivalent decline in muscle mass. These rates of UCE decrease were similar in survivors, non-survivors, males and females underscoring the intransigent nature of this process. In contrast to measured creatinine clearance, estimates of eGFR progressively rose during ICU stay.

Enhanced renal clearance and impact on vancomycin pharmacokinetic parameters in patients with hemorrhagic stroke

BACKGROUND

The majority of patients with hemorrhagic stroke experience enhanced renal clearance or augmented renal clearance (ARC). The purpose of this study was to determine the impact of enhanced renal clearance or ARC on vancomycin pharmacokinetic (PK) parameters.

METHODS

This was a post hoc analysis of a prospective study of adult patients with aneurysmal subarachnoid hemorrhage (aSAH) or intracerebral hemorrhage (ICH) admitted to the neurosciences intensive care unit who received vancomycin. Creatinine clearance (CrCl) was measured and also estimated using the Cockcroft-Gault equation. Predicted PK parameters were compared with calculated PK parameters using serum peak and trough concentrations.

RESULTS

Seventeen hemorrhagic stroke patients met inclusion criteria. All patients experienced enhanced renal clearance on the day that the vancomycin concentrations were obtained, and 12 patients (71%) experienced ARC. The mean calculated elimination rate constant was significantly higher than the predicted value (0.141 ± 0.02 vs. 0.087 ± 0.01 h-1; p = 0.004) and the mean calculated half-life was significantly lower than the predicted half-life (6.5 ± 0.9 vs. 8.7 ± 0.6 h; p = 0.03).

CONCLUSIONS

Patients with hemorrhagic stroke and enhanced renal clearance displayed PK alterations favoring an increased elimination of vancomycin than expected. This may result in underexposure to vancomycin, leading to treatment failure.