Restrictive versus standard IV fluid therapy in adult ICU patients with septic shock-Bayesian analyses of the CLASSIC trial

Effects of IV Fluid Restriction According to Standard Fluid Treatment Intensity Across Conservative Versus Liberal Approach to Fluid Therapy of Septic Shock in Intensive Care (CLASSIC) Trial Sites

OBJECTIVES

In the Conservative vs. Liberal Approach to Fluid Therapy of Septic Shock in Intensive Care (CLASSIC) trial, restriction of IV fluid volumes led to similar overall mortality in ICU patients with septic shock. We assessed if variation in standard IV fluid treatment intensity across sites impacted the effects of fluid restriction.

DESIGN

Secondary analysis of randomized clinical trial.

SETTING

ICU.

PATIENTS

The CLASSIC trial enrolled adult ICU patients with septic shock. We included 1366 participants from 19 sites, representing 88% of the full trial population. All sites with greater than or equal to 15 participants in the standard-fluid group were included in this study.

INTERVENTIONS

Restrictive vs. standard IV fluid therapy.

MEASUREMENTS AND MAIN RESULTS

We used machine learning (eXtreme Gradient Boosting) to predict the IV fluid volumes in the first 24 hours in the standard-fluid group while accounting for participant characteristics that could contribute to treatment variations. We then classified sites into intensity subgroups based on the mean differences between predicted and administered IV fluid volumes in the first 24 hours in the standard-fluid group. We assessed the intervention effects on mortality, serious adverse events and reactions, days alive without life support, and days alive out of hospital at day 90 across these intensity subgroups, using hierarchical Bayesian models with weakly informative priors. Sensitivity analyses evaluated intervention effects separately in each site. In the standard-fluid group, the median absolute difference between administered and predicted IV fluid volumes was -118 mL (interquartile range, -1,341 to 1,731 mL; full range, -5,873 to 11,761 mL). Sites were categorized into five intensity subgroups. The absolute differences in mortality across these subgroups ranged from -2.7% point to 1.4% point. We found similar effects of restrictive vs. standard IV fluid treatment on all outcomes within the intensity subgroups. Results were similar in the sensitivity analyses.

CONCLUSIONS

Among adult ICU patients with septic shock, variation in standard IV fluid volumes across sites did not substantially impact the effects of fluid restriction on outcomes after accounting for patient characteristics.

The effect of high protein dosing in critically ill patients: an exploratory, secondary Bayesian analyses of the EFFORT Protein trial

BACKGROUND

The EFFORT Protein trial assessed the effect of high vs usual dosing of protein in adult ICU patients with organ failure. This study provides a probabilistic interpretation and evaluates heterogeneity in treatment effects (HTE).

METHODS

We analysed 60-day all-cause mortality and time to discharge alive from hospital using Bayesian models with weakly informative priors. HTE on mortality was assessed according to disease severity (Sequential Organ Failure Assessment [SOFA] score), acute kidney injury, and serum creatinine values at baseline.

RESULTS

The absolute difference in mortality was 2.5% points (95% credible interval -6.9 to 12.4), with a 72% posterior probability of harm associated with high protein treatment. For time to discharge alive from hospital, the hazard ratio was 0.91 (95% credible interval 0.80 to 1.04) with a 92% probability of harm for the high-dose protein group compared with the usual-dose protein group. There were 97% and 95% probabilities of positive interactions between the high protein intervention and serum creatinine and SOFA score at randomisation, respectively. Specifically, there was a potentially relatively higher mortality of high protein doses with higher baseline serum creatinine or SOFA scores.

CONCLUSIONS

We found moderate to high probabilities of harm with high protein doses compared with usual protein in ICU patients for the primary and secondary outcomes. We found suggestions of heterogeneity in treatment effects with worse outcomes in participants randomised to high protein doses with renal dysfunction or acute kidney injury and greater illness severity at baseline.

Identifying septic shock subgroups to tailor fluid strategies through multi-omics integration

Fluid management remains a critical challenge in the treatment of septic shock, with individualized approaches lacking. This study aims to develop a statistical model based on transcriptomics to identify subgroups of septic shock patients with varied responses to fluid strategy. The study encompasses 494 septic shock patients. A benefit score is derived from the transcriptome space, with higher values indicating greater benefits from restrictive fluid strategy. Adherence to the recommended strategy is associated with a hazard ratio of 0.82 (95% confidence interval: 0.64-0.92). When applied to the baseline hospital mortality rate of 16%, adherence to the recommended fluid strategy could potentially lower this rate to 13%. A proteomic signature comprising six proteins is developed to predict the benefit score, yielding an area under the curve of 0.802 (95% confidence interval: 0.752-0.846) in classifying patients who may benefit from a restrictive strategy. In this work, we develop a proteomic signature with potential utility in guiding fluid strategy for septic shock patients.

Effects of IV fluid restriction according to site-specific intensity of standard fluid treatment-protocol

BACKGROUND

Variation in usual practice in fluid trials assessing lower versus higher volumes may affect overall comparisons. To address this, we will evaluate the effects of heterogeneity in treatment intensity in the Conservative versus Liberal Approach to Fluid Therapy of Septic Shock in Intensive Care trial. This will reflect the effects of differences in site-specific intensities of standard fluid treatment due to local practice preferences while considering participant characteristics.

METHODS

We will assess the effects of heterogeneity in treatment intensity across one primary (all-cause mortality) and three secondary outcomes (serious adverse events or reactions, days alive without life support and days alive out of hospital) after 90 days. We will classify sites based on the site-specific intensity of standard fluid treatment, defined as the mean differences in observed versus predicted intravenous fluid volumes in the first 24 h in the standard-fluid group while accounting for differences in participant characteristics. Predictions will be made using a machine learning model including 22 baseline predictors using the extreme gradient boosting algorithm. Subsequently, sites will be grouped into fluid treatment intensity subgroups containing at least 100 participants each. Subgroups differences will be assessed using hierarchical Bayesian regression models with weakly informative priors. We will present the full posterior distributions of relative (risk ratios and ratios of means) and absolute differences (risk differences and mean differences) in each subgroup.

DISCUSSION

This study will provide data on the effects of heterogeneity in treatment intensity while accounting for patient characteristics in critically ill adult patients with septic shock.

REGISTRATIONS

The European Clinical Trials Database (EudraCT): 2018-000404-42, ClinicalTrials. gov: NCT03668236.

Fluid accumulation syndrome in sepsis and septic shock: pathophysiology, relevance and treatment-a comprehensive review

In this review, we aimed to comprehensively summarize current literature on pathophysiology, relevance, diagnosis and treatment of fluid accumulation in patients with sepsis/septic shock. Fluid accumulation syndrome (FAS) is defined as fluid accumulation (any degree, expressed as percentage from baseline body weight) with new onset organ-failure. Over the years, many studies have described the negative impact of FAS on clinically relevant outcomes. While the relationship between FAS and ICU outcomes is well described, uncertainty exists regarding its diagnosis, monitoring and treatment. A stepwise approach is suggested to prevent and treat FAS in patients with septic shock, including minimizing fluid intake (e.g., by limiting intravenous fluid administration and employing de-escalation whenever possible), limiting sodium and chloride administration, and maximizing fluid output (e.g., with diuretics, or renal replacement therapy). Current literature implies the need for a multi-tier, multi-modal approach to de-resuscitation, combining a restrictive fluid management regime with a standardized early active de-resuscitation, maintenance fluid reduction (avoiding fluid creep) and potentially using physical measures such as compression stockings.Trial registration: Not applicable.