Aiko Tanaka

Extended Daily Dialysis Versus Continuous Renal Replacement Therapy for Acute Kidney Injury: A Meta-analysis.

BACKGROUND Extended daily dialysis (EDD) has been suggested as an effective renal replacement therapy for acute kidney injury. However, results from studies comparing EDD to continuous renal replacement therapy (CRRT) are inconclusive. STUDY DESIGN A systematic review and meta-analysis was performed by searching in MEDLINE, EMBASE, the Cochrane Library, Google Scholar, and a Chinese database (SinsoMed). SETTING & POPULATION Patients with acute kidney injury. SELECTION CRITERIA FOR STUDIES Randomized controlled trials (RCTs) and observational studies were included. EDD was defined as extended hemodialysis or hemodiafiltration for more than 6 but less than 24 hours per session using a conventional hemodialysis machine. INTERVENTION Renal replacement therapy comparing EDD with CRRT. OUTCOMES Mortality, kidney recovery, and fluid removal. RESULTS We included 17 studies from 2000 to 2014: 7 RCTs and 10 observational studies involving 533 and 675 patients, respectively. Meta-analysis of RCTs showed no difference in mortality rates between EDD and CRRT (relative risk, 0.90; 95% CI, 0.74-1.11; P=0.3). However, EDD was associated with lower mortality risk compared with CRRT in observational studies (relative risk, 0.86; 95% CI, 0.74-1.00; P=0.05). There was no evidence of heterogeneity in RCTs (I(2)=0%) or observational studies (I(2)=15%). In both RCTs and observational studies, there were no significant differences in recovery of kidney function, fluid removal, or days in the intensive care unit, and EDD showed similar biochemical efficacy to CRRT during treatment (serum urea, serum creatinine, and serum phosphate). LIMITATIONS The survival benefit of EDD is dependent on only observational studies and might have been affected by allocation or selection bias. CONCLUSIONS EDD is associated with similar outcomes to CRRT in RCTs. The finding that EDD is associated with a lower mortality rate relies on data from observational studies, which are potentially subject to allocation or selection bias, making further high-quality RCTs desirable.

Targeted therapeutic mild hypercapnia after cardiac arrest: A phase II multi-centre randomised controlled trial (the CCC trial)☆

BACKGROUND In intensive care observational studies, hypercapnia after cardiac arrest (CA) is independently associated with improved neurological outcome. However, the safety and feasibility of delivering targeted therapeutic mild hypercapnia (TTMH) for such patients is untested. METHODS In a phase II safety and feasibility multi-centre, randomised controlled trial, we allocated ICU patients after CA to 24h of targeted normocapnia (TN) (PaCO2 35-45mmHg) or TTMH (PaCO2 50-55mmHg). The primary outcome was serum neuron specific enolase (NSE) and S100b protein concentrations over the first 72h assessed in the first 50 patients surviving to day three. Secondary end-points included global measure of function assessment at six months and mortality for all patients. RESULTS We enrolled 86 patients. Their median age was 61 years (58, 64 years) and 66 (79%) were male. Of these, 50 patients (58%) survived to day three for full biomarker assessment. NSE concentrations increased in the TTMH group (p=0.02) and TN group (p=0.005) over time, with the increase being significantly more pronounced in the TN group (p(interaction)=0.04). S100b concentrations decreased over time in the TTMH group (p<0.001) but not in the TN group (p=0.68). However, the S100b change over time did not differ between the groups (p(interaction)=0.23). At six months, 23 (59%) TTMH patients had good functional recovery compared with 18 (46%) TN patients. Hospital mortality occurred in 11 (26%) TTMH patients and 15 (37%) TN patients (p=0.31). CONCLUSIONS In CA patients admitted to the ICU, TTMH was feasible, appeared safe and attenuated the release of NSE compared with TN. These findings justify further investigation of this novel treatment.

Bioelectrical impedance vector analysis in critically ill patients: a prospective, clinician-blinded investigation

IntroductionAssessment of fluid status in critically ill patients is challenging. We aimed to assess the feasibility and validity of bioelectrical impedance vector analysis (BIVA) as a measure of hydration in critically ill patients.MethodsWe performed twice-daily BIVA measurements and fluid balance calculations and recorded physiological variables in mechanically ventilated patients within 24 h of intensive care unit (ICU) admission for up to 5 days. Treating clinicians were blinded to BIVA results.ResultsWe performed 344 BIVA measurements in 61 patients. According to BIVA, 14 patients (23 %) were dehydrated, 22 (36 %) were normally hydrated and 25 (41 %) were overhydrated upon ICU admission. Patients with normal BIVA hydration were less sick, had fewer comorbidities and had less deranged physiology than patients found to be dehydrated or overhydrated with BIVA. Cumulative fluid balance increased in patients found to be dehydrated with BIVA by a mean of 3.4±2.2 L, whereas in patients found to be overhydrated with BIVA, it decreased by a mean of 4.5±6.9 L. In patients found to be normally hydrated with BIVA, fluid balance remained unchanged. BIVA-defined hydration increased with 1 L (median change 1.5 %, P =0.09) or 2 L (median change 0.7 %, P =0.09) of calculated fluid gains. BIVA-defined hydration decreased (median change −0.8 %, P =0.02) with a negative cumulative fluid balance of >2 L. BIVA-defined hydration between first and last measurement correlated with the corresponding change in fluid balance (ρ =0.25, P =0.05).ConclusionsBIVA is feasible in critically ill patients. Its validity is supported by the observed characteristics of patients with different degrees of BIVA hydration upon admission and by different fluid management of such patients by blinded clinicians. The sensitivity of repeated BIVA hydration measurements to detect fluid accumulation or fluid balance changes <2 L was low, however. These contradictory findings provide the rational basis for studies of BIVA-assisted fluid management in ICU patients.

Remote Ischemic Conditioning for Kidney Protection: A Meta-Analysis

BACKGROUND Results from randomized controlled trials (RCTs) concerning kidney effect of remote ischemic conditioning (RIC) are inconsistent. METHODS We searched for relevant studies in Medline, Embase, the Cochrane Library, Google Scholar and Chinese database (SinoMed), as well as relevant references from their inception to November 2015. We performed a systematic review and meta-analysis of all eligible RCTs of RIC with kidney events. RESULTS We included 37 RCTs from 2007 to 2015 involving 8168 patients. Pooled analyses of all RCTs showed RIC significantly reduced the incidence of investigator-defined acute kidney injury (AKI) compared with control groups (RR 0.84, 95% CI 0.73-0.96, P = .009) (I(2) = 25%). However, the difference was not significant when only RIFLE (Risk, Injury, Failure, Loss, End Stage), AKIN (Acute Kidney Injury Network), or KDIGO (Kidney Disease Improving Global Outcomes) criteria were applied to the definition of AKI (RR 0.87, 95% CI 0.74-1.02, P = .08) (I(2) = 22%). In subgroup analysis, RIC showed a significant benefit on reducing investigator-defined AKI in patients following percutaneous coronary intervention (RR 0.64, 95% CI 0.46-0.87), but not after cardiac surgery (RR 0.93, 95% CI 0.82-1.06). There was no difference for changes in the incidence of renal replacement therapy, estimated glomerular filtration rate or serum creatinine. CONCLUSIONS RIC might be beneficial for the prevention of investigator-defined AKI; however, the effect is likely small. Moreover, due to lack of an effect on use of renal replacement therapy, estimated glomerular filtration rate, RIFLE, AKIN, or KDIGO-defined AKI, and serum creatinine, the evidence for RIC is not robust. Finally, recent large-scale RCTs of RIC focusing on patient-centered outcomes do not support the wider application of RIC.

Cerebral oxygenation in mechanically ventilated early cardiac arrest survivors: The impact of hypercapnia

BACKGROUND Optimal cerebral oxygenation is considered fundamental to cerebral protection in cardiac arrest (CA) patients. Hypercapnia increases cerebral blood flow and may also improve cerebral oxygenation. It is uncertain, however, whether this effect occurs in mechanically ventilated early survivors of CA. METHODS We enrolled mechanically ventilated resuscitated patients within 36h of their cardiac arrest. We performed a prospective double cross-over physiological study comparing the impact of normocapnia (PaCO2 35-45mmHg) vs. mild hypercapnia (PaCO2 45-55mmHg) on regional cerebral tissue oxygen saturation (SctO2) assessed by near infrared spectroscopy (NIRS). RESULTS We studied seven adult CA patients with a median time to return of spontaneous circulation of 28min at a median of 26h and 30min after CA. During normocapnia (median EtCO2 of 32mmHg [30-41mmHg] and PaCO2 of 37mmHg [32-45mmHg]) the median NIRS-derived left frontal SctO2 was 61% [52-65%] and the right frontal SctO2 was 61% [54-68%]. However, during mild hypercapnia (median EtCO2 of 49mmHg [40-57mmHg] and PaCO2 of 52mmHg [43-55mmHg) the median left frontal SctO2 increased to 69% [59-78%] and the right frontal SctO2 increased to 73% [61-76%])(p=0.001, for all comparisons). CONCLUSION During the early post-resuscitation period, in mechanically ventilated CA patients, mild hypercapnia increases cerebral oxygenation as assessed by NIRS. Further investigations of the effect of prolonged mild hypercapnia on cerebral oxygenation and patient outcomes appear justified.

Defining the characteristics and expectations of fluid bolus therapy: A worldwide perspective

PURPOSE The purpose of the study is to understand what clinicians believe defines fluid bolus therapy (FBT) and the expected response to such intervention. METHODS We asked intensive care specialists in 30 countries to participate in an electronic questionnaire of their practice, definition, and expectations of FBT. RESULTS We obtained 3138 responses. Despite much variation, more than 80% of respondents felt that more than 250 mL of either colloid or crystalloid fluid given over less than 30 minutes defined FBT, with crystalloids most acceptable. The most acceptable crystalloid and colloid for use as FBT were 0.9% saline and 4% albumin solution, respectively. Most respondents believed that one or more of the following physiological changes indicates a response to FBT: a mean arterial pressure increase greater than 10 mm Hg, a heart rate decrease greater than 10 beats per minute, an increase in urinary output by more than 10 mL/h, an increase in central venous oxygen saturation greater than 4%, or a lactate decrease greater than 1 mmol/L. CONCLUSIONS Despite wide variability between individuals and countries, clear majority views emerged to describe practice, define FBT, and identify a response to it. Further investigation is now required to describe actual FBT practice and to identify the magnitude and duration of the physiological response to FBT and its relationship to patient-centered outcomes.

Glycated Hemoglobin A1c Levels Are Not Affected by Critical Illness

Objectives: Glycated hemoglobin A1c is used to estimate glycemic control. However, its value upon ICU admission may be altered by critical illness and not reflect true glycemic status. We assessed the relationship between ICU admission glycated hemoglobin A1c and premorbid glycated hemoglobin A1c levels. Design: Retrospective observational cohort study. Setting: Two tertiary ICUs in Australia. Patients: Cohort of 69 critically ill patients with diabetes and glycated hemoglobin A1c levels measured upon ICU admission and during the month prior to admission. Interventions: Measurement of glycated hemoglobin A1c. Measurements and Main Results: Mean (SD) glycated hemoglobin A1c level was 7.5% (1.8%) upon ICU admission and 7.8% (2.0%) in previous measurements from the preceding 30 days. The change in glycated hemoglobin A1c did not correlate with time elapsed between the two measurements (r 2 = 0.00005; p = 0.95), but there was a strong correlation between admission glycated hemoglobin A1c levels and premorbid glycated hemoglobin A1c levels (r 2 = 0.89; p < 0.001). Conclusions: Glycated hemoglobin A1c levels are not altered by the onset of critical illness. Glycated hemoglobin A1c quantified at ICU admission can, therefore, be used to reliably estimate chronic glycemic control and guide acute glycemic therapy.

Contents Vol. 41, 2016

Annual Congress of the 293 Chinese Blood Purification Center Administration Commitee August 20–22, 2015, Tianjin, China Guest Editor: Tao Wei (Beijing) (available online only