Assessing SOFA score trajectories in sepsis using machine learning: A pragmatic approach to improve the accuracy of mortality prediction

INTRODUCTION

An increasing amount of longitudinal health data is available on critically ill septic patients in the age of digital medicine, including daily sequential organ failure assessment (SOFA) score measurements. Thus, the assessment in sepsis focuses increasingly on the evaluation of the individual disease's trajectory. Machine learning (ML) algorithms may provide a promising approach here to improve the evaluation of daily SOFA score dynamics. We tested whether ML algorithms can outperform the conventional ΔSOFA score regarding the accuracy of 30-day mortality prediction.

METHODS

We used the multicentric SepsisDataNet.NRW study cohort that prospectively enrolled 252 sepsis patients between 03/2018 and 09/2019 for training ML algorithms, i.e. support vector machine (SVM) with polynomial kernel and artificial neural network (aNN). We used the Amsterdam UMC database covering 1,790 sepsis patients for external and independent validation.

RESULTS

Both SVM (AUC 0.84; 95% CI: 0.71-0.96) and aNN (AUC 0.82; 95% CI: 0.69-0.95) assessing the SOFA scores of the first seven days led to a more accurate prognosis of 30-day mortality compared to the ΔSOFA score between day 1 and 7 (AUC 0.73; 95% CI: 0.65-0.80; p = 0.02 and p = 0.05, respectively). These differences were even more prominent the shorter the time interval considered. Using the SOFA scores of day 1 to 3 SVM (AUC 0.82; 95% CI: 0.68 0.95) and aNN (AUC 0.80; 95% CI: 0.660.93) led to a more accurate prognosis of 30-day mortality compared to the ΔSOFA score (AUC 0.66; 95% CI: 0.58-0.74; p < 0.01 and p < 0.01, respectively). Strikingly, all these findings could be confirmed in the independent external validation cohort.

CONCLUSIONS

The ML-based algorithms using daily SOFA scores markedly improved the accuracy of mortality compared to the conventional ΔSOFA score. Therefore, this approach could provide a promising and automated approach to assess the individual disease trajectory in sepsis. These findings reflect the potential of incorporating ML algorithms as robust and generalizable support tools on intensive care units.

Timely Cessation of Proton Pump Inhibitors in Critically Ill Patients Impacts Morbidity and Mortality: A Propensity Score-Matched Cohort Study

OBJECTIVE

Proton pump inhibitors (PPIs) are among the drugs most commonly used in critically ill patients. Although mainly applied temporarily for stress ulcer prophylaxis, their application is frequently not terminated. Potential adverse effects of PPI treatment could impact the outcome in case of unnecessary and, therefore, avoidable long-term continuation. We tested the hypotheses that nonindicated PPI therapy continued beyond hospital discharge is associated with increased morbidity, rehospitalization rate, and mortality.

DESIGN

Nationwide retrospective cohort study considering critically ill patients treated on German ICUs between January, 2017, and December, 2018 with a 2-year follow-up.

SETTING

A total of 591,207 patient datasets of a German healthcare insurer were screened.

PATIENTS

We identified 11,576 ICU patients who received PPI therapy for the first time during their index ICU stay without having an indication for its continuation.

INTERVENTIONS

The cohort was stratified into two groups: 1) patients without further PPI therapy and 2) patients with continuation of PPI therapy beyond 8 weeks after hospital discharge.

MEASUREMENTS AND MAIN RESULTS

Frequency of predescribed adverse events associated with PPI therapy, 1-year rehospitalization rate, and 2-year mortality were determined. The proportion of patients with continued PPI therapy without an objectifiable indication was 41.7% (4,825 of 11,576 patients). These patients had a 27% greater risk of pneumonia (odds ratio [OR] 1.27; 95% CI, 1.15-1.39; p < 0.001) and a 17% greater risk of cardiovascular events (OR 1.17; 95% CI, 1.08-1.26; p < 0.001). Continued PPI therapy was associated with a 34% greater risk of rehospitalization (OR 1.34; 95% CI, 1.23-1.47) and a nearly 20% greater 2-year mortality risk (hazard ratio 1.17; 95% CI, 1.08-1.27; p = 0.006).

CONCLUSIONS

These data demonstrate that an unnecessary continuation of PPI therapy after hospital discharge may significantly impact morbidity and mortality. To avoid potentially harmful overuse of a PPIs, intensivists should ensure timely cessation of a temporarily indicated PPI therapy.

The Aquaporin 3 Polymorphism (rs17553719) Is Associated with Sepsis Survival and Correlated with IL-33 Secretion

Sepsis is a common life-threatening disease caused by dysregulated immune response and metabolic acidosis which lead to organ failure. An abnormal expression of aquaporins plays an important role in organ failure. Additionally, genetic variants in aquaporins impact on the outcome in sepsis. Thus, we investigated the polymorphism (rs17553719) and expression of aquaporin-3 (AQP3) and correlated these measurements with the survival of sepsis patients. Accordingly, we collected blood samples on several days (plus clinical data) from 265 sepsis patients who stayed in different ICUs in Germany. Serum plasma, DNA, and RNA were then separated to detect the promotor genotypes of AQP3 mRNA expression of AQP3 and several cytokines. The results showed that the homozygote CC genotype exhibited a significant decrease in 30-day survival (38.9%) compared to the CT (66.15%) and TT genotypes (76.3%) (p = 0.003). Moreover, AQP3 mRNA expression was significantly higher and nearly doubled in the CC compared to the CT (p = 0.0044) and TT genotypes (p = 0.018) on the day of study inclusion. This was accompanied by an increased IL-33 concentration in the CC genotype (day 0: p = 0.0026 and day 3: p = 0.008). In summary, the C allele of the AQP3 polymorphism (rs17553719) shows an association with increased AQP3 expression and IL-33 concentration accompanied by decreased survival in patients with sepsis.

AQP3 and AQP9-Contrary Players in Sepsis?

Sepsis involves an immunological systemic response to a microbial pathogenic insult, leading to a cascade of interconnected biochemical, cellular, and organ-organ interaction networks. Potential drug targets can depict aquaporins, as they are involved in immunological processes. In immune cells, AQP3 and AQP9 are of special interest. In this study, we tested the hypothesis that these aquaporins are expressed in the blood cells of septic patients and impact sepsis survival. Clinical data, routine laboratory parameters, and blood samples from septic patients were analyzed on day 1 and day 8 after sepsis diagnosis. AQP expression and cytokine serum concentrations were measured. AQP3 mRNA expression increased over the duration of sepsis and was correlated with lymphocyte count. High AQP3 expression was associated with increased survival. In contrast, AQP9 expression was not altered during sepsis and was correlated with neutrophil count, and low levels of AQP9 were associated with increased survival. Furthermore, AQP9 expression was an independent risk factor for sepsis lethality. In conclusion, AQP3 and AQP9 may play contrary roles in the pathophysiology of sepsis, and these results suggest that AQP9 may be a novel drug target in sepsis and, concurrently, a valuable biomarker of the disease.

Methazolamide Reduces the AQP5 mRNA Expression and Immune Cell Migration-A New Potential Drug in Sepsis Therapy?

Sepsis is a life-threatening condition caused by the dysregulated host response to infection. Novel therapeutic options are urgently needed and aquaporin inhibitors could suffice as aquaporin 5 (Aqp5) knockdown provided enhanced sepsis survival in a murine sepsis model. Potential AQP5 inhibitors provide sulfonamides and their derivatives. In this study, we tested the hypothesis that sulfonamides reduce AQP5 expression in different conditions. The impact of sulfonamides on AQP5 expression and immune cell migration was examined in cell lines REH and RAW 264.7 by qPCR, Western blot and migration assay. Subsequently, whether furosemide and methazolamide are capable of reducing AQP5 expression after LPS incubation was investigated in whole blood samples of healthy volunteers. Incubation with methazolamide (10-5 M) and furosemide (10-6 M) reduced AQP5 mRNA and protein expression by about 30% in REH cells. Pre-incubation of the cells with methazolamide reduced cell migration towards SDF1-α compared to non-preincubated cells to control level. Pre-incubation with methazolamide in PBMCs led to a reduction in LPS-induced AQP5 expression compared to control levels, while furosemide failed to reduce it. Methazolamide appears to reduce AQP5 expression and migration of immune cells. However, after LPS administration, the reduction in AQP5 expression by methazolamide is no longer possible. Hence, our study indicates that methazolamide is capable of reducing AQP5 expression and has the potential to be used in sepsis prophylaxis.

Die neue internationale Sepsis-Leitlinie der Surviving Sepsis Campaign 2021

The new Surviving Sepsis Campaign (SSC) guideline was substantially revised in 2021. These updated recommendations are intended to guide intensivists in providing adequate care to adult patients with sepsis or septic shock. In particular, the current SSC guideline emphasizes early recognition and stringent management in the first hours after the onset of sepsis. In particular, the implementation of acute interventions should help to improve the chances of survival of sepsis patients.This article summarizes the most important recommendations for acute therapy and presents them as a comparative overview to the previous SSC guideline and the German S3 guideline. This should allow the reader to adopt the knowledge from the new guideline into clinical practice as quickly as possible in order to improve the quality of treatment of patients with sepsis or septic shock.

Carbon recovery from screenings for energy-efficient wastewater treatment

The energy content of screenings from six municipal wastewater treatment plants (WWTPs) was examined. Hourly samples of separated screenings were taken over 24 hours at three of the plants to illustrate diurnal variations. To recover the chemical energy, which usually leaves the WWTP with the screenings, a screenings wash press was used to transfer organic matter from the solid into the liquid phase. The chemical energy of raw and compacted washed screenings as well as the chemical energy of washing water were determined by measuring the chemical oxygen demand (COD) for the six WWTPs. A mass weighted average of 1.35 g_COD/g_dm (dm: dry matter) was found in the raw screenings of three WWTPs. The overall recovered energy from screenings was found to range from 0.27 to 0.62 g_COD/g_dm. This washed-out COD found in the washing water could be sent for anaerobic digestion or to the wastewater treatment process as a carbon source for denitrification.

Full scale membrane bioreactor treatment of hospital wastewater as forerunner for hot-spot wastewater treatment solutions in high density urban areas

Membrane Bioreactors (MBR) are a very attractive option for the treatment of hospital wastewater and elimination of pharmaceuticals in high density urban areas. The present investigation showed that, depending on the substance, between 19% and 94% of the level of antibiotics found in the environment originate from hospitals. Because of their ecotoxic potential, hospital wastewaters can have a significant impact on the environment. The segregation of these wastewaters and their separate treatment at the source can reduce the entry of drugs in waterways and enable water reuse after adequate polishing treatment processes.

Ultrasonic treatment to improve anaerobic digestibility of dairy waste streams

The dairy-processing industry generates various types of organic wastes, which are utilised as stock feed, for anaerobic digestion, spread on land or alternatively land-filled at high costs. Owing to the generation of renewable energy, anaerobic digestion is an attractive option for many factories. To enhance the biological degradation process, a mechanical disintegration of various waste dairy streams was undertaken. While the successful application of ultrasonic treatment has been reported for various municipal waste streams, limited information was available for dairy industry applications. The results of this study showed that ultrasonic treatment can improve the digestibility of the more problematic dairy waste streams, such as sludges, by breaking down micro-organisms' cell walls and releasing soluble cell compounds. For more soluble streams, such as dairy factory effluent, an increased gas production was observed and attributed to the reduced particle size of the fat globules.