Calorie intake and patient outcomes in severe acute kidney injury: findings from The Randomized Evaluation of Normal vs. Augmented Level of Replacement Therapy (RENAL) study trial

Introduction

Current practice in the delivery of caloric intake (DCI) in patients with severe acute kidney injury (AKI) receiving renal replacement therapy (RRT) is unknown. We aimed to describe calorie administration in patients enrolled in the Randomized Evaluation of Normal vs. Augmented Level of Replacement Therapy (RENAL) study and to assess the association between DCI and clinical outcomes.

Methods

We performed a secondary analysis in 1456 patients from the RENAL trial. We measured the dose and evolution of DCI during treatment and analyzed its association with major clinical outcomes using multivariable logistic regression, Cox proportional hazards models, and time adjusted models.

Results

Overall, mean DCI during treatment in ICU was low at only 10.9 ± 9 Kcal/kg/day for non-survivors and 11 ± 9 Kcal/kg/day for survivors. Among patients with a lower DCI (below the median) 334 of 729 (45.8%) had died at 90-days after randomization compared with 316 of 727 (43.3%) patients with a higher DCI (above the median) (P = 0.34). On multivariable logistic regression analysis, mean DCI carried an odds ratio of 0.95 (95% confidence interval (CI): 0.91-1.00; P = 0.06) per 100 Kcal increase for 90-day mortality. DCI was not associated with significant differences in renal replacement (RRT) free days, mechanical ventilation free days, ICU free days and hospital free days. These findings remained essentially unaltered after time adjusted analysis and Cox proportional hazards modeling.

Conclusions

In the RENAL study, mean DCI was low. Within the limits of such low caloric intake, greater DCI was not associated with improved clinical outcomes.

Trial registration

ClinicalTrials.gov number, {"type":"clinical-trial","attrs":{"text":"NCT00221013","term_id":"NCT00221013"}}NCT00221013     

The effect of continuous versus intermittent renal replacement therapy on the outcome of critically ill patients with acute renal failure (CONVINT): a prospective randomized controlled trial

Introduction

Acute renal failure (ARF) requiring renal replacement therapy (RRT) occurs frequently in ICU patients and significantly affects mortality rates. Previously, few large clinical trials investigated the impact of RRT modalities on patient outcomes. Here we investigated the effect of two major RRT strategies (intermittent hemodialysis (IHD) and continuous veno-venous hemofiltration (CVVH)) on mortality and renal-related outcome measures.

Methods

This single-center prospective randomized controlled trial (“CONVINT”) included 252 critically ill patients (159 male; mean age, 61.5 ± 13.9 years; Acute Physiology and Chronic Health Evaluation (APACHE) II score, 28.6 ± 8.8) with dialysis-dependent ARF treated in the ICUs of a tertiary care academic center. Patients were randomized to receive either daily IHD or CVVH. The primary outcome measure was survival at 14 days after the end of RRT. Secondary outcome measures included 30-day-, intensive care unit-, and intrahospital mortality, as well as course of disease severity/biomarkers and need for organ-support therapy.

Results

At baseline, no differences in disease severity, distributions of age and gender, or suspected reasons for acute renal failure were observed. Survival rates at 14 days after RRT were 39.5% (IHD) versus 43.9% (CVVH) (odds ratio (OR), 0.84; 95% confidence interval (CI), 0.49 to 1.41; P = 0.50). 14-day-, 30-day, and all-cause intrahospital mortality rates were not different between the two groups (all P > 0.5). No differences were observed in days on RRT, vasopressor days, days on ventilator, or ICU-/intrahospital length of stay.

Conclusions

In a monocentric RCT, we observed no statistically significant differences between the investigated treatment modalities regarding mortality, renal-related outcome measures, or survival at 14 days after RRT. Our findings add to mounting data demonstrating that intermittent and continuous RRTs may be considered equivalent approaches for critically ill patients with dialysis-dependent acute renal failure.

Trial registration

{"type":"clinical-trial","attrs":{"text":"NCT01228123","term_id":"NCT01228123"}}NCT01228123, clinicaltrials.gov     

Short-term effects of noisy pressure support ventilation in patients with acute hypoxemic respiratory failure

Introduction

This study aims at comparing the very short-term effects of conventional and noisy (variable) pressure support ventilation (PSV) in mechanically ventilated patients with acute hypoxemic respiratory failure.

Methods

Thirteen mechanically ventilated patients with acute hypoxemic respiratory failure were enrolled in this monocentric, randomized crossover study. Patients were mechanically ventilated with conventional and noisy PSV, for one hour each, in random sequence. Pressure support was titrated to reach tidal volumes approximately 8 mL/kg in both modes. The level of positive end-expiratory pressure and fraction of inspired oxygen were kept unchanged in both modes. The coefficient of variation of pressure support during noisy PSV was set at 30%. Gas exchange, hemodynamics, lung functional parameters, distribution of ventilation by electrical impedance tomography, breathing patterns and patient-ventilator synchrony were analyzed.

Results

Noisy PSV was not associated with any adverse event, and was well tolerated by all patients. Gas exchange, hemodynamics, respiratory mechanics and spatial distribution of ventilation did not differ significantly between conventional and noisy PSV. Noisy PSV increased the variability of tidal volume (24.4 ± 7.8% vs. 13.7 ± 9.1%, P <0.05) and was associated with a reduced number of asynchrony events compared to conventional PSV (5 (0 to 15)/30 min vs. 10 (1 to 37)/30 min, P <0.05).

Conclusions

In the very short term, noisy PSV proved safe and feasible in patients with acute hypoxemic respiratory failure. Compared to conventional PSV, noisy PSV increased the variability of tidal volumes, and was associated with improved patient-ventilator synchrony, at comparable levels of gas exchange.

Trial registration

ClinicialTrials.gov, {"type":"clinical-trial","attrs":{"text":"NCT00786292","term_id":"NCT00786292"}}NCT00786292     

Intravenous angiotensin II for the treatment of high-output shock (ATHOS trial): a pilot study

Introduction

Patients with distributive shock who require high dose vasopressors have a high mortality. Angiotensin II (ATII) may prove useful in patients who remain hypotensive despite catecholamine and vasopressin therapy. The appropriate dose of parenteral angiotensin II for shock is unknown.

Methods

In total, 20 patients with distributive shock and a cardiovascular Sequential Organ Failure Assessment score of 4 were randomized to either ATII infusion (N =10) or placebo (N =10) plus standard of care. ATII was started at a dose of 20 ng/kg/min, and titrated for a goal of maintaining a mean arterial pressure (MAP) of 65 mmHg. The infusion (either ATII or placebo) was continued for 6 hours then titrated off. The primary endpoint was the effect of ATII on the standing dose of norepinephrine required to maintain a MAP of 65 mmHg.

Results

ATII resulted in marked reduction in norepinephrine dosing in all patients. The mean hour 1 norepinephrine dose for the placebo cohort was 27.6 ± 29.3 mcg/min versus 7.4 ± 12.4 mcg/min for the ATII cohort (P =0.06). The most common adverse event attributable to ATII was hypertension, which occurred in 20% of patients receiving ATII. 30-day mortality for the ATII cohort and the placebo cohort was similar (50% versus 60%, P =1.00).

Conclusion

Angiotensin II is an effective rescue vasopressor agent in patients with distributive shock requiring multiple vasopressors. The initial dose range of ATII that appears to be appropriate for patients with distributive shock is 2 to 10 ng/kg/min.

Trial registration

Clinicaltrials.gov {"type":"clinical-trial","attrs":{"text":"NCT01393782","term_id":"NCT01393782"}}NCT01393782. Registered 12 July 2011.     

Long-term outcome in early survivors of cardiogenic shock at the acute stage of myocardial infarction: a landmark analysis from the French registry of Acute ST-elevation and non-ST-elevation Myocardial Infarction (FAST-MI) Registry

Introduction

There are little data about patients with cardiogenic shock (CS) who survive the early phase of acute myocardial infarction (AMI). The aim of this study was to assess long-term (5-year) mortality among early survivors of AMI, according to the presence of CS at the acute stage.

Methods

We analyzed 5-year follow-up data from the French registry of Acute ST-elevation and non-ST-elevation Myocardial Infarction (FAST-MI) 2005 registry, a nationwide French survey including consecutive patients admitted for ST or non-ST-elevation AMI at the end of 2005 in 223 institutions.

Results

Of 3670 patients enrolled, shock occurred in 224 (6.1%), and 3411 survived beyond 30 days or hospital discharge, including 99 (2.9%) with shock. Early survivors with CS had a more severe clinical profile, more frequent concomitant in-hospital complications, and were less often managed invasively than those without CS.Five-year survival was 59% in patients with, versus 76% in those without shock (adjusted hazard ratio (HR) = 1.72 [1.24-2.38], P = 0.001). The excess of death associated with CS, however, was observed only during the first year (one-year survival: 77% vs 93%, adjusted HR: 2.87 [1.85 to 4.46] P <0.001), while survival from one to 5 years was similar (76% vs 82%, adjusted HR: 1.06 [0.64 to 1.74]). Propensity score-matched analyses yielded similar results.

Conclusions

In patients surviving the early phase of AMI, CS at the initial stage carries an increased risk of death up to one year after the acute event. Beyond one year, however, mortality is similar to that of patients without shock.

Trial registration

ClinicalTrials.gov number, {"type":"clinical-trial","attrs":{"text":"NCT00673036","term_id":"NCT00673036"}}NCT00673036, Registered May 5, 2008.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-014-0516-y) contains supplementary material, which is available to authorized users.     

Early fluid resuscitation with hydroxyethyl starch 130/0.4 (6%) in severe burn injury: a randomized,controlled, double-blind clinical trial

Introduction

There are limited data on the efficacy of early fluid resuscitation with third-generation hydroxyethyl starch (HES 130) in burn injury. Adverse effects of HES on survival and organ function have been reported.

Methods

In this randomized, controlled, double-blind trial, 48 patients with severe burn injury were assigned to receive either lactated Ringer’s solution plus 6% HES 130/0.4 in a ratio of 2:1 or lactated Ringer’s solution with no colloid supplement for the first 72 hours. Primary outcome parameter was the group difference of administered total fluid from intensive care unit (ICU) admission up to day 3. Secondary outcomes included kidney and lung injury and failure, length of stay, and mortality.

Results

Three-day totals of administered resuscitation fluid (medians) were 21,190 mL in the lactated Ringer’s group and 19,535 mL in the HES group (HES: −1,213 mL; P = 0.39). Creatinine levels from day 1 to 3 (HES: +0.4 μmol/L; 95% confidence interval (CI) −18.7 to 19.5; P = 0.97) and urinary outputs from day 1 to 3 (HES: −58 mL; 95% CI −400 to 283; P = 0.90) were not different. Six patients in each group developed acute respiratory distress syndrome (ARDS) (risk ratio 0.96; 95% CI 0.35 to 2.64; P = 0.95). Length of ICU stay (HES vs. lactated Ringer’s: 28 vs. 24 days; P = 0.80) and length of hospital stay (31 vs. 29 days; P = 0.57) were similar. Twenty-eight-day mortality was 4 patients in each group (risk ratio 0.96; 95% CI 0.27 to 4.45; P = 0.95), and in-hospital mortality was 8 in the HES group vs. 5 patients in the lactated Ringer’s group (hazard ratio 1.86; 95% CI 0.56 to 6.19; P = 0.31).

Conclusions

There was no evidence that early fluid resuscitation with balanced HES 130/0.4 (6%) in addition to lactated Ringer’s solution would lead to a volume-sparing effect in severe burn injury. Together with the findings that early renal function, incidence of ARDS, length of stay, and mortality were not negatively influenced by HES in this setting, balanced HES 130/0.4 (6%) plus lactated Ringer’s solution could not be considered superior to lactated Ringer’s solution alone.

Trial registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT01012648","term_id":"NCT01012648"}}NCT01012648     

Considerations when measuring myocardial perfusion reserve by cardiovascular magnetic resonance using regadenoson

Background

Adenosine cardiovascular magnetic resonance (CMR) can accurately quantify myocardial perfusion reserve. While regadenoson is increasingly employed due to ease of use, imaging protocols have not been standardized. We sought to determine the optimal regadenoson CMR protocol for quantifying myocardial perfusion reserve index (MPRi) – more specifically, whether regadenoson stress imaging should be performed before or after rest imaging.

Methods

Twenty healthy subjects underwent CMR perfusion imaging during resting conditions, during regadenoson-induced hyperemia (0.4 mg), and after 15 min of recovery. In 10/20 subjects, recovery was facilitated with aminophylline (125 mg). Myocardial time-intensity curves were used to obtain left ventricular cavity-normalized myocardial up-slopes. MPRi was calculated in two different ways: as the up-slope ratio of stress to rest (MPRi-rest), and the up-slope ratio of stress to recovery (MPRi-recov).

Results

In all 20 subjects, MPRi-rest was 1.78 ± 0.60. Recovery up-slope did not return to resting levels, regardless of aminophylline use. Among patients not receiving aminophylline, MPRi-recov was 36 ± 16% lower than MPRi-rest (1.13 ± 0.38 vs. 1.82 ± 0.73, P = 0.001). In the 10 patients whose recovery was facilitated with aminophylline, MPRi-recov was 20 ± 24% lower than MPRi-rest (1.40 ± 0.35 vs. 1.73 ± 0.43, P = 0.04), indicating incomplete reversal. In 3 subjects not receiving aminophylline and 4 subjects receiving aminophylline, up-slope at recovery was greater than at stress, suggesting delayed maximal hyperemia.

Conclusions

MPRi measurements from regadenoson CMR are underestimated if recovery perfusion is used as a substitute for resting perfusion, even when recovery is facilitated with aminophylline. True resting images should be used to allow accurate MPRi quantification. The delayed maximal hyperemia observed in some subjects deserves further study.

Trial registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT00871260","term_id":"NCT00871260"}}NCT00871260     

Fibroblast growth factor 23 in acute myocardial infarction complicated by cardiogenic shock: a biomarker substudy of the Intraaortic Balloon Pump in Cardiogenic Shock II (IABP-SHOCK II) trial

Introduction

Cardiogenic shock (CS) is the leading cause of death in patients hospitalized with acute myocardial infarction (AMI). Biomarkers might help in risk stratification and understanding of pathophysiology. Preliminary data suggests that patients with CS face a profound increase in the osteocyte-derived hormone fibroblast growth factor 23 (FGF-23), which acts as a negative regulator of serum phosphate levels. The present study aimed to assess the predictive role of FGF-23 for clinical outcome in a large cohort of CS patients with and without renal dysfunction.

Methods

In the randomized Intraaortic Balloon Pump in Cardiogenic Shock II (IABP-SHOCK II) trial, 600 patients with CS complicating AMI were assigned to therapy with or without IABP. Our predefined biomarker substudy included 182 patients. Blood sampling was performed in a standardized procedure at three different time points (day 1 (day of admission), day 2 and day 3). Differences in outcome of patients with FGF-23 levels < and > median were compared by log-rank testing. Stepwise logistic regression modeling was performed to identify predictors of death at 30 days and Cox regression analysis for time to death during the first year.

Results

At all three time points, nonsurvivors had significantly higher FGF-23 levels compared to survivors (P <0.001 for all). Patients with FGF-23 levels above the median (395 RU/mL [interquartile range 102;2,395]) were characterized by an increased 30-day mortality and 1-year mortality. In multivariable analysis FGF-23 levels remained independent predictors for 30-day (odds ratio per 10log 1.80, 95% confidence interval (CI) 1.11 to 2.92; P = 0.02) and 1-year mortality (hazard ratio 1.50, 95% CI 1.11 to 2.04, P = 0.009). After stratifying the patients according to their baseline serum creatinine levels, the negative prognostic association of increased FGF-23 was only significant in those with serum creatinine greater than median.

Conclusions

In CS, high levels of FGF-23 are independently related to a poor clinical outcome. However, this prognostic association appears only to apply in patients with impaired renal function.

Trial registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT00491036","term_id":"NCT00491036"}}NCT00491036. Registered 22 June 2007.     

Microcirculatory effects of the transfusion of leukodepleted or non-leukodepleted red blood cells in patients with sepsis: a pilot study

Introduction

Microvascular alterations impair tissue oxygenation during sepsis. A red blood cell (RBC) transfusion increases oxygen (O₂) delivery but rarely improves tissue O₂ uptake in patients with sepsis. Possible causes include RBC alterations due to prolonged storage or residual leukocyte-derived inflammatory mediators. The aim of this study was to compare the effects of two types of transfused RBCs on microcirculation in patients with sepsis.

Methods

In a prospective randomized trial, 20 patients with sepsis were divided into two separate groups and received either non-leukodepleted (n = 10) or leukodepleted (n = 10) RBC transfusions. Microvascular density and perfusion were assessed with sidestream dark field (SDF) imaging sublingually, before and 1 hour after transfusions. Thenar tissue O₂ saturation (StO₂) and tissue hemoglobin index (THI) were determined with near-infrared spectroscopy, and a vascular occlusion test was performed. The microcirculatory perfused boundary region was assessed in SDF images as an index of glycocalyx damage, and glycocalyx compounds (syndecan-1, hyaluronan, and heparan sulfate) were measured in the serum.

Results

No differences were observed in microvascular parameters at baseline and after transfusion between the groups, except for the proportion of perfused vessels (PPV) and blood flow velocity, which were higher after transfusion in the leukodepleted group. Microvascular flow index in small vessels (MFI) and blood flow velocity exhibited different responses to transfusion between the two groups (P = 0.03 and P = 0.04, respectively), with a positive effect of leukodepleted RBCs. When within-group changes were examined, microcirculatory improvement was observed only in patients who received leukodepleted RBC transfusion as suggested by the increase in De Backer score (P = 0.02), perfused vessel density (P = 0.04), PPV (P = 0.01), and MFI (P = 0.04). Blood flow velocity decreased in the non-leukodepleted group (P = 0.03). THI and StO₂ upslope increased in both groups. StO₂ and StO₂ downslope increased in patients who received non-leukodepleted RBC transfusions. Syndecan-1 increased after the transfusion of non-leukodepleted RBCs (P = 0.03).

Conclusions

This study does not show a clear superiority of leukodepleted over non-leukodepleted RBC transfusions on microvascular perfusion in patients with sepsis, although it suggests a more favorable effect of leukodepleted RBCs on microcirculatory convective flow. Further studies are needed to confirm these findings.

Trial registration

ClinicalTrials.gov, {"type":"clinical-trial","attrs":{"text":"NCT01584999","term_id":"NCT01584999"}}NCT01584999     

Effect of erythropoietin on the incidence of acute kidney injury following complex valvular heart surgery: a double blind,randomized clinical trial of efficacy and safety

Introduction

Recombinant human erythropoietin (EPO) is known to provide organ protection against ischemia-reperfusion injury through its pleiotropic properties. The aim of this single-site, randomized, case-controlled, and double-blind study was to investigate the effect of pre-emptive EPO administration on the incidence of postoperative acute kidney injury (AKI) in patients with risk factors for AKI undergoing complex valvular heart surgery.

Methods

We studied ninety-eight patients with preoperative risk factors for AKI. The patients were randomly allocated to either the EPO group (n = 49) or the control group (n = 49). The EPO group received 300 IU/kg of EPO intravenously after anesthetic induction. The control group received an equivalent volume of normal saline. AKI was defined as an increase in serum creatinine >0.3 mg/dl or >50% from baseline. Biomarkers of renal injury were serially measured until five days postoperatively.

Results

Patient characteristics and operative data, including the duration of cardiopulmonary bypass, were similar between the two groups. Incidence of postoperative AKI (32.7% versus 34.7%, P = 0.831) and biomarkers of renal injury including cystatin C and neutrophil gelatinase-associated lipocalin showed no significant differences between the groups. The postoperative increase in interleukin-6 and myeloperoxidase was similar between the groups. None of the patients developed adverse complications related to EPO administration, including thromboembolic events, throughout the study period.

Conclusions

Intravenous administration of 300 IU/kg of EPO did not provide renal protection in patients who are at increased risk of developing AKI after undergoing complex valvular heart surgery.

Trial registration

Clinical Trial.gov, {"type":"clinical-trial","attrs":{"text":"NCT01758861","term_id":"NCT01758861"}}NCT01758861     

Continuous positive airway pressure and ventilation are more effective with a nasal mask than a full face mask in unconscious subjects: a randomized controlled trial

Introduction

Upper airway obstruction (UAO) is a major problem in unconscious subjects, making full face mask ventilation difficult. The mechanism of UAO in unconscious subjects shares many similarities with that of obstructive sleep apnea (OSA), especially the hypotonic upper airway seen during rapid eye movement sleep. Continuous positive airway pressure (CPAP) via nasal mask is more effective at maintaining airway patency than a full face mask in patients with OSA. We hypothesized that CPAP via nasal mask and ventilation (nCPAP) would be more effective than full face mask CPAP and ventilation (FmCPAP) for unconscious subjects, and we tested our hypothesis during induction of general anesthesia for elective surgery.

Methods

In total, 73 adult subjects requiring general anesthesia were randomly assigned to one of four groups: nCPAP P0, nCPAP P5, FmCPAP P0, and FmCPAP P5, where P0 and P5 represent positive end-expiratory pressure (PEEP) 0 and 5 cm H₂O applied prior to induction. After apnea, ventilation was initiated with pressure control ventilation at a peak inspiratory pressure over PEEP (PIP/PEEP) of 20/0, then 20/5, and finally 20/10 cm H₂O, each applied for 1 min. At each pressure setting, expired tidal volume (Vte) was calculated by using a plethysmograph device.

Results

The rate of effective tidal volume (Vte > estimated anatomical dead space) was higher (87.9% vs. 21.9%; P<0.01) and the median Vte was larger (6.9 vs. 0 mL/kg; P<0.01) with nCPAP than with FmCPAP. Application of CPAP prior to induction of general anesthesia did not affect Vte in either approach (nCPAP pre- vs. post-; 7.9 vs. 5.8 mL/kg, P = 0.07) (FmCPAP pre- vs. post-; 0 vs. 0 mL/kg, P = 0.11).

Conclusions

nCPAP produced more effective tidal volume than FmCPAP in unconscious subjects.

Trial registration

ClinicalTrials.gov identifier: {"type":"clinical-trial","attrs":{"text":"NCT01524614","term_id":"NCT01524614"}}NCT01524614.     

Half-molar sodium lactate infusion improves cardiac performance in acute heart failure: a pilot randomised controlled clinical trial

Introduction

Acute heart failure (AHF) is characterized by inadequate cardiac output (CO), congestive symptoms, poor peripheral perfusion and end-organ dysfunction. Treatment often includes a combination of diuretics, oxygen, positive pressure ventilation, inotropes and vasodilators or vasopressors. Lactate is a marker of illness severity but is also an important metabolic substrate for the myocardium at rest and during stress. We tested the effects of half-molar sodium lactate infusion on cardiac performance in AHF.

Methods

We conducted a prospective, randomised, controlled, open-label, pilot clinical trial in 40 patients fulfilling two of the following three criteria for AHF: (1) left ventricular ejection fraction <40%, (2) acute pulmonary oedema or respiratory failure of predominantly cardiac origin requiring mechanical ventilation and (3) currently receiving vasopressor and/or inotropic support. Patients in the intervention group received a 3 ml/kg bolus of half-molar sodium lactate over the course of 15 minutes followed by 1 ml/kg/h continuous infusion for 24 hours. The control group received only a 3 ml/kg bolus of Hartmann’s solution without continuous infusion. The primary outcome was CO assessed by transthoracic echocardiography 24 hours after randomisation. Secondary outcomes included a measure of right ventricular systolic function (tricuspid annular plane systolic excursion (TAPSE)), acid-base balance, electrolyte and organ function parameters, along with length of stay and mortality.

Results

The infusion of half-molar sodium lactate increased (mean ± SD) CO from 4.05 ± 1.37 L/min to 5.49 ± 1.9 L/min (P < 0.01) and TAPSE from 14.7 ± 5.5 mm to 18.3 ± 7 mm (P = 0.02). Plasma sodium and pH increased (136 ± 4 to 146 ± 6 and 7.40 ± 0.06 to 7.53 ± 0.03, respectively; both P < 0.01), but potassium, chloride and phosphate levels decreased. There were no significant differences in the need for vasoactive therapy, respiratory support, renal or liver function tests, duration of ICU and hospital stay or 28- and 90-day mortality.

Conclusions

Infusion of half-molar sodium lactate improved cardiac performance and led to metabolic alkalosis in AHF patients without any detrimental effects on organ function.

Trial registration

Clinicaltrials.gov {"type":"clinical-trial","attrs":{"text":"NCT01981655","term_id":"NCT01981655"}}NCT01981655. Registered 13 August 2013.     

Variability of linezolid concentrations after standard dosing in critically ill patients: a prospective observational study

Introduction

Severe infections in intensive care patients show high morbidity and mortality rates. Linezolid is an antimicrobial drug frequently used in critically ill patients. Recent data indicates that there might be high variability of linezolid serum concentrations in intensive care patients receiving standard doses. This study was aimed to evaluate whether standard dosing of linezolid leads to therapeutic serum concentrations in critically ill patients.

Methods

In this prospective observational study, 30 critically ill adult patients with suspected infections received standard dosing of 600 mg linezolid intravenously twice a day. Over 4 days, multiple serum samples were obtained from each patient, in order to determine the linezolid concentrations by liquid chromatography tandem mass spectrometry.

Results

A high variability of serum linezolid concentrations was observed (range of area under the linezolid concentration time curve over 24 hours (AUC₂₄) 50.1 to 453.9 mg/L, median 143.3 mg*h/L; range of trough concentrations (C_min) < 0.13 to 14.49 mg/L, median 2.06 mg/L). Furthermore, potentially subtherapeutic linezolid concentrations over 24 hours and at single time points (defined according to the literature as AUC₂₄ < 200 mg*h/L and C_min < 2 mg/L) were observed for 63% and 50% of the patients, respectively. Finally, potentially toxic levels (defined as AUC₂₄ > 400 mg*h/L and C_min > 10 mg/L) were observed for 7 of the patients.

Conclusions

A high variability of linezolid serum concentrations with a substantial percentage of potentially subtherapeutic levels was observed in intensive care patients. The findings suggest that therapeutic drug monitoring of linezolid might be helpful for adequate dosing of linezolid in critically ill patients.

Trial registration

Clinicaltrials.gov {"type":"clinical-trial","attrs":{"text":"NCT01793012","term_id":"NCT01793012"}}NCT01793012. Registered 24 January 2013.     

Impairment of cardiac metabolism and sympathetic innervation after aneurysmal subarachnoid hemorrhage: a nuclear medicine imaging study

Introduction

Although aneurysmal subarachnoid hemorrhage (SAH) is often complicated by myocardial injury, whether this neurogenic cardiomyopathy is associated with the modification of cardiac metabolism is unknown. This study sought to explore, by positron emission tomography/computed tomography, the presence of altered cardiac glucose metabolism after SAH.

Methods

During a 16-month period, 30 SAH acute phase patients underwent myocardial ¹⁸ F- fluorodesoxyglucose positron emission tomography (¹⁸F-FDGPET), ^99mTc-tetrofosmin and ¹²³I-meta-iodobenzylguanidine (¹²³I-mIBG) scintigraphy, respectively, assessing glucose metabolism, cardiac perfusion, and sympathetic innervation. Patients with initial abnormalities were followed monthly for two months for ¹⁸F-FDG, and six months later for ¹²³I-mIBG.

Results

In this SAH population, acute cardiac metabolic disturbance was observed in 83% of patients (n = 25), and sympathetic innervation disturbance affected 90% (n = 27). Myocardial perfusion was normal for all patients. The topography and extent of metabolic defects and innervation abnormalities largely overlapped. Follow-up showed rapid improvement of glucose metabolism in one or two months. Normalization of sympathetic innervation was slower; only 27% of patients (n = 8) exhibited normal ¹²³I-mIBG scintigraphy after six months. Presence of initial altered cardiac metabolism was not associated with more unfavorable cardiac or neurological outcomes.

Conclusions

These findings support the hypothesis of neurogenic myocardial stunning after SAH. In hemodynamically stable acute phase SAH patients, cardiomyopathy is characterized by diffuse and heterogeneous ¹⁸F-FDG and ¹²³I-mIBG uptake defect.

Trial registration

Clinicaltrials.gov {"type":"clinical-trial","attrs":{"text":"NCT01218191","term_id":"NCT01218191"}}NCT01218191. Registered 6 October 2010.     

Effect of a fever control protocol-based strategy on ventilator-associated pneumonia in severely brain-injured patients

Introduction

Fever is associated with a poor outcome in severely brain-injured patients, and its control is one of the therapies used in this condition. But, fever suppression may promote infection, and severely brain-injured patients are frequently exposed to infectious diseases, particularly ventilator-associated pneumonia (VAP). Therefore, we designed a study to explore the role of a fever control protocol in VAP development during neuro-intensive care.

Methods

An observational study was performed on severely brain-injured patients hospitalized in a university ICU. The primary goal was to assess whether fever control was a risk factor for VAP in a prospective cohort in which a fever control protocol was applied and in a historical control group. Moreover, the density of VAP incidence was compared between the two groups. The statistical analysis was based on a competing risk model multivariate analysis.

Results

The study included 189 brain-injured patients (intervention group, n = 98, and historical control group, n = 91). The use of a fever control protocol was an independent risk factor for VAP (hazard ratio 2.73, 95% confidence interval (1.38, 5.38; P = 0.005)). There was a significant increase in the incidence of VAP in patients treated with a fever control protocol (26.1 versus 12.5 VAP cases per 1000 days of mechanical ventilation). In cases in which a fever control protocol was applied for >3 days, we observed a higher rate of VAP in comparison with the rate among patients treated for ≤3 days.

Conclusions

Fever control in brain-injured patients was a major risk factor for VAP occurrence, particularly when applied for >3 days.     

Heart–lung interactions during neurally adjusted ventilatory assist

Introduction

Assist in unison to the patient’s inspiratory neural effort and feedback-controlled limitation of lung distension with neurally adjusted ventilatory assist (NAVA) may reduce the negative effects of mechanical ventilation on right ventricular function.

Methods

Heart–lung interaction was evaluated in 10 intubated patients with impaired cardiac function using esophageal balloons, pulmonary artery catheters and echocardiography. Adequate NAVA level identified by a titration procedure to breathing pattern (NAVAal), 50% NAVAal, and 200% NAVAal and adequate pressure support (PSVal, defined clinically), 50% PSVal, and 150% PSVal were implemented at constant positive end-expiratory pressure for 20 minutes each.

Results

NAVAal was 3.1 ± 1.1cmH₂O/μV and PSVal was 17 ± 2 cmH₂0. For all NAVA levels negative esophageal pressure deflections were observed during inspiration whereas this pattern was reversed during PSVal and PSVhigh. As compared to expiration, inspiratory right ventricular outflow tract velocity time integral (surrogating stroke volume) was 103 ± 4%, 109 ± 5%, and 100 ± 4% for NAVAlow, NAVAal, and NAVAhigh and 101 ± 3%, 89 ± 6%, and 83 ± 9% for PSVlow, PSVal, and PSVhigh, respectively (p < 0.001 level-mode interaction, ANOVA). Right ventricular systolic isovolumetric pressure increased from 11.0 ± 4.6 mmHg at PSVlow to 14.0 ± 4.6 mmHg at PSVhigh but remained unchanged (11.5 ± 4.7 mmHg (NAVAlow) and 10.8 ± 4.2 mmHg (NAVAhigh), level-mode interaction p = 0.005). Both indicate progressive right ventricular outflow impedance with increasing pressure support ventilation (PSV), but no change with increasing NAVA level.

Conclusions

Right ventricular performance is less impaired during NAVA compared to PSV as used in this study. Proposed mechanisms are preservation of cyclic intrathoracic pressure changes characteristic of spontaneous breathing and limitation of right-ventricular outflow impedance during inspiration, regardless of the NAVA level.

Trial registration

Clinicaltrials.gov Identifier: {"type":"clinical-trial","attrs":{"text":"NCT00647361","term_id":"NCT00647361"}}NCT00647361, registered 19 March 2008

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-014-0499-8) contains supplementary material, which is available to authorized users.     

Comparative evaluation of three interfaces for non-invasive ventilation: a randomized cross-over design physiologic study on healthy volunteers

Introduction

Interface choice is crucial for non-invasive ventilation (NIV) success. We compared a new interface, the helmet next (H_N), with the facial mask (FM) and the standard helmet (H_S) in twelve healthy volunteers.

Methods

In this study, five NIV trials were randomly applied, preceded and followed by a trial of unassisted spontaneous breathing (SB). Baseline settings, for example, 5 cmH₂O of both inspiratory pressure support (PS) and positive end-expiratory pressure (PEEP), were applied through FM, H_S and H_N, while increased settings (PS and PEEP of 8 cmH₂O) were only applied through H_S and H_N. We measured flow, airway, esophageal and gastric pressures, and calculated inspiratory effort indexes and trigger delays. Comfort was assessed with a visual-analog-scale.

Results

We found that FM, H_S and H_N at baseline settings were not significantly different with respect to inspiratory effort indexes and comfort. Inspiratory trigger delay and time of synchrony (TI,synchrony) were significantly improved by FM compared to both helmets, whereas expiratory trigger delay was shorter with FM, as opposed to H_S only. H_N at increased settings performed better than FM in decreasing inspiratory effort measured by pressure-time product of transdiaphragmatic pressure (PTPdi)/breath (10.7 ± 9.9 versus 17.0 ± 11.0 cmH₂O*s), and PTPdi/min (128 ± 96 versus 204 ± 81 cmH₂O*s/min), and PTPdi/L (12.6 ± 9.9 versus 30.2 ± 16.8 cmH₂O*s/L). TI, synchrony was inferior between H_N and H_S at increased settings and FM.

Conclusions

H_N might hold some advantages with respect to interaction and synchrony between subject and ventilator, but studies on patients are needed to confirm these findings.

Trial registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT01610960","term_id":"NCT01610960"}}NCT01610960     

Prolonged continuous intravenous infusion of the dipeptide L-alanine- L-glutamine significantly increases plasma glutamine and alanine without elevating brain glutamate in patients with severe traumatic brain injury

Introduction

Low plasma glutamine levels are associated with worse clinical outcome. Intravenous glutamine infusion dose- dependently increases plasma glutamine levels, thereby correcting hypoglutaminemia. Glutamine may be transformed to glutamate which might limit its application at a higher dose in patients with severe traumatic brain injury (TBI). To date, the optimal glutamine dose required to normalize plasma glutamine levels without increasing plasma and cerebral glutamate has not yet been defined.

Methods

Changes in plasma and cerebral glutamine, alanine, and glutamate as well as indirect signs of metabolic impairment reflected by increased intracranial pressure (ICP), lactate, lactate-to-pyruvate ratio, electroencephalogram (EEG) activity were determined before, during, and after continuous intravenous infusion of 0.75 g L-alanine-L-glutamine which was given either for 24 hours (group 1, n = 6) or 5 days (group 2, n = 6) in addition to regular enteral nutrition. Lab values including nitrogen balance, urea and ammonia were determined daily.

Results

Continuous L-alanine-L-glutamine infusion significantly increased plasma and cerebral glutamine as well as alanine levels, being mostly sustained during the 5 day infusion phase (plasma glutamine: from 295 ± 62 to 500 ± 145 μmol/ l; brain glutamine: from 183 ± 188 to 549 ± 120 μmol/ l; plasma alanine: from 327 ± 91 to 622 ± 182 μmol/ l; brain alanine: from 48 ± 55 to 89 ± 129 μmol/ l; p < 0.05, ANOVA, post hoc Dunn’s test).Plasma glutamate remained unchanged and cerebral glutamate was decreased without any signs of cerebral impairment. Urea and ammonia were significantly increased within normal limits without signs of organ dysfunction (urea: from 2.7 ± 1.6 to 5.5 ± 1.5 mmol/ l; ammonia: from 12 ± 6.3 to 26 ± 8.3 μmol/ l; p < 0.05, ANOVA, post hoc Dunn’s test).

Conclusions

High dose L-alanine-L-glutamine infusion (0.75 g/ kg/ d up to 5 days) increased plasma and brain glutamine and alanine levels. This was not associated with elevated glutamate or signs of potential glutamate-mediated cerebral injury. The increased nitrogen load should be considered in patients with renal and hepatic dysfunction.

Trial registration

Clinicaltrials.gov {"type":"clinical-trial","attrs":{"text":"NCT02130674","term_id":"NCT02130674"}}NCT02130674. Registered 5 April 2014     

Left ventricular global function index assessed by cardiovascular magnetic resonance for the prediction of cardiovascular events in ST-elevation myocardial infarction

Background

The left ventricular performance index (LVGFI) as a comprehensive marker of cardiac performance integrates LV structure with global function within one index. In a prospective cohort study of healthy individuals the LVGFI demonstrated a superior prognostic value as compared to LV ejection fraction (LVEF). In patients after ST-segment elevation myocardial infarction (STEMI), however, the role of the LVGFI is unknown. Aim of this study was to investigate the relationship between the LVGFI and infarct characteristics as well as prognosis in a large multicenter STEMI population.

Methods

In total 795 STEMI patients reperfused by primary angioplasty (<12 h after symptom onset) underwent cardiovascular magnetic resonance (CMR) at 8 centers. CMR was completed within one week after infarction using a standardized protocol including LV dimensions, mass and function for calculation of the LVGFI. The primary clinical endpoint of the study was the occurrence of major adverse cardiac events (MACE).

Results

The median LVGFI was 31.2 % (interquartile range 25.7 to 36.6). Patients with LVGFI < median had significantly larger infarcts, less myocardial salvage, a larger extent of microvascular obstruction, higher incidence of intramyocardial hemorrhage and more pronounced LV dysfunction (p < 0.001 for all). MACE and mortality rates were significantly higher in the LVGFI < median group (p < 0.001 and p = 0.003, respectively). The LVGFI had an incremental prognostic value in addition to LVEF for prediction of all-cause mortality.

Conclusions

The LVGFI strongly correlates with markers of severe myocardial and microvascular damage in patients with STEMI, offering prognostic information beyond traditional cardiac risk factors including the LVEF.

Trials registration

ClinicalTrials.gov: {"type":"clinical-trial","attrs":{"text":"NCT00712101","term_id":"NCT00712101"}}NCT00712101     

Continuous versus bolus intermittent loop diuretic infusion in acutely decompensated heart failure: a prospective randomized trial

Introduction

Intravenous loop diuretics are a cornerstone of therapy in acutely decompensated heart failure (ADHF). We sought to determine if there are any differences in clinical outcomes between intravenous bolus and continuous infusion of loop diuretics.

Methods

Subjects with ADHF within 12 hours of hospital admission were randomly assigned to continuous infusion or twice daily bolus therapy with furosemide. There were three co-primary endpoints assessed from admission to discharge: the mean paired changes in serum creatinine, estimated glomerular filtration rate (eGFR), and reduction in B-type natriuretic peptide (BNP). Secondary endpoints included the rate of acute kidney injury (AKI), change in body weight and six months follow-up evaluation after discharge.

Results

A total of 43 received a continuous infusion and 39 were assigned to bolus treatment. At discharge, the mean change in serum creatinine was higher (+0.8 ± 0.4 versus -0.8 ± 0.3 mg/dl P <0.01), and eGFR was lower (-9 ± 7 versus +5 ± 6 ml/min/1.73 m²P <0.05) in the continuous arm. There was no significant difference in the degree of weight loss (-4.1 ± 1.9 versus -3.5 ± 2.4 kg P = 0.23). The continuous infusion arm had a greater reduction in BNP over the hospital course, (-576 ± 655 versus -181 ± 527 pg/ml P = 0.02). The rates of AKI were comparable (22% and 15% P = 0.3) between the two groups. There was more frequent use of hypertonic saline solutions for hyponatremia (33% versus 18% P <0.01), intravenous dopamine infusions (35% versus 23% P = 0.02), and the hospital length of stay was longer in the continuous infusion group (14. 3 ± 5 versus 11.5 ± 4 days, P <0.03). At 6 months there were higher rates of re-admission or death in the continuous infusion group, 58% versus 23%, (P = 0.001) and this mode of treatment independently associated with this outcome after adjusting for baseline and intermediate variables (adjusted hazard ratio = 2.57, 95% confidence interval, 1.01 to 6.58 P = 0.04).

Conclusions

In the setting of ADHF, continuous infusion of loop diuretics resulted in greater reductions in BNP from admission to discharge. However, this appeared to occur at the consequence of worsened renal filtration function, use of additional treatment, and higher rates of rehospitalization or death at six months.

Trial registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT01441245","term_id":"NCT01441245"}}NCT01441245. Registered 23 September 2011.