Association between early cumulative fluid balance and successful liberation from invasive ventilation in COVID-19 ARDS patients — insights from the PRoVENT-COVID study: a national, multicenter, observational cohort analysis

Background

Increasing evidence indicates the potential benefits of restricted fluid management in critically ill patients. Evidence lacks on the optimal fluid management strategy for invasively ventilated COVID-19 patients. We hypothesized that the cumulative fluid balance would affect the successful liberation of invasive ventilation in COVID-19 patients with acute respiratory distress syndrome (ARDS).

Methods

We analyzed data from the multicenter observational ‘PRactice of VENTilation in COVID-19 patients’ study. Patients with confirmed COVID-19 and ARDS who required invasive ventilation during the first 3 months of the international outbreak (March 1, 2020, to June 2020) across 22 hospitals in the Netherlands were included. The primary outcome was successful liberation of invasive ventilation, modeled as a function of day 3 cumulative fluid balance using Cox proportional hazards models, using the crude and the adjusted association. Sensitivity analyses without missing data and modeling ARDS severity were performed.

Results

Among 650 patients, three groups were identified. Patients in the higher, intermediate, and lower groups had a median cumulative fluid balance of 1.98 L (1.27–7.72 L), 0.78 L (0.26–1.27 L), and − 0.35 L (− 6.52–0.26 L), respectively. Higher day 3 cumulative fluid balance was significantly associated with a lower probability of successful ventilation liberation (adjusted hazard ratio 0.86, 95% CI 0.77–0.95, P = 0.0047). Sensitivity analyses showed similar results.

Conclusions

In a cohort of invasively ventilated patients with COVID-19 and ARDS, a higher cumulative fluid balance was associated with a longer ventilation duration, indicating that restricted fluid management in these patients may be beneficial.

Trial registration Clinicaltrials.gov (NCT04346342); Date of registration: April 15, 2020.

Graphical abstract

Comparison of patient characteristics and long‐term mortality between transferred and non‐transferred COVID‐19 patients in Dutch Intensive Care Units; A national cohort study

Background

COVID‐19 patients were often transferred to other intensive care units (ICUs) to prevent that ICUs would reach their maximum capacity. However, transferring ICU patients is not free of risk. We aim to compare the characteristics and outcomes of transferred versus non‐transferred COVID‐19 ICU patients in the Netherlands.

Methods

We included adult COVID‐19 patients admitted to Dutch ICUs between March 1, 2020 and July 1, 2021. We compared the patient characteristics and outcomes of non‐transferred and transferred patients and used a Directed Acyclic Graph to identify potential confounders in the relationship between transfer and mortality. We used these confounders in a Cox regression model with left truncation at the day of transfer to analyze the effect of transfers on mortality during the 180 days after ICU admission.

Results

We included 10,209 patients: 7395 non‐transferred and 2814 (27.6%) transferred patients. In both groups, the median age was 64 years. Transferred patients were mostly ventilated at ICU admission (83.7% vs. 56.2%) and included a larger proportion of low‐risk patients (70.3% vs. 66.5% with mortality risk <30%). After adjusting for age, APACHE IV mortality probability, BMI, mechanical ventilation, and vasoactive medication use, the hazard of mortality during the first 180 days was similar for transferred patients compared to non‐transferred patients (HR [95% CI] = 0.99 [0.91–1.08]).

Conclusions

Transferred COVID‐19 patients are more often mechanically ventilated and are less severely ill compared to non‐transferred patients. Furthermore, transferring critically ill COVID‐19 patients in the Netherlands is not associated with mortality during the first 180 days after ICU admission.

Nephrotoxicity of continuous amphotericin B in critically ill patients with abdominal sepsis: a retrospective analysis with propensity score matching

BACKGROUND

Continuous infusion of conventional amphotericin B (CCAB) is used in ICUs for pre-emptive treatment of invasive fungal infections. Amphotericin B has previously been associated with nephrotoxicity.

OBJECTIVES

To investigate if CCAB with therapeutic drug monitoring (TDM) results in renal impairment over time in critically ill patients with abdominal sepsis.

PATIENTS AND METHODS

The study was conducted at mixed medical-surgical ICUs of two large teaching hospitals in the Netherlands. Consecutive patients who were treated on the ICUs between 2006 and 2019 for abdominal sepsis, with or without CCAB, were included. CCAB dosing was guided by TDM. Serum creatinine concentrations and renal failure scores of patients with CCAB treatment were compared with those without CCAB treatment. Excluded were: (i) patients treated with CCAB for less than 72 h; and (ii) patients with renal replacement therapy.

RESULTS

A total of 319 patients were included (185 treated with CCAB and 134 controls). A multiple linear regression model showed that the serum creatinine concentration was independent of CCAB treatment (β = -0.023; 95% CI = -12.2 to 7.2; P = 0.615). Propensity score matching resulted in 134 pairs of CCAB-treated and non-treated patients. Again, the analysis of these pairs showed that the cumulative CCAB dose was not associated with serum creatinine concentration during intensive care treatment (β = 0.299; 95% CI = -0.38 to 0.98; P = 0.388).

CONCLUSIONS

CCAB with TDM did not result in renal impairment over time in critically ill patients with abdominal sepsis.

The development of a glucose prediction model in critically ill patients

PURPOSE

The aim of the current study is to develop a prediction model for glucose levels applicable for all patients admitted to the ICU with an expected ICU stay of at least 24 h. This model will be incorporated in a closed-loop glucose system to continuously and automatically control glucose values.

METHODS

Data from a previous single-center randomized controlled study was used. All patients received a FreeStyle Navigator II subcutaneous CGM system from Abbott during their ICU stay. The total dataset was randomly divided into a training set and a validation set. A glucose prediction model was developed based on historical glucose data. Accuracy of the prediction model was determined using the Mean Squared Difference (MSD), the Mean Absolute Difference (MAD) and a Clarke Error Grid (CEG).

RESULTS

The dataset included 94 ICU patients with a total of 134,673 glucose measurements points that were used for modelling. MSD was 0.410 ± 0.495 for the model, the MAD was 5.19 ± 2.63 and in the CEG 99.8% of the data points were in the clinically acceptable regions.

CONCLUSION

In this study a glucose prediction model for ICU patients is developed. This study shows that it is possible to accurately predict a patient's glucose 30 min ahead based on historical glucose data. This is the first step in the development of a closed-loop glucose system.

Anti-infectious decontamination strategies in Dutch intensive care units: A survey study on contemporary practice and heterogeneity

PURPOSE

Despite increasing evidence and updated national guidelines, practice of anti-infectious strategies appears to vary in the Netherlands. This study aimed to determine the variation of current practices of anti-infectious strategies in Dutch ICUs.

MATERIALS AND METHODS

In 2018 and 2019 an online survey of all Dutch ICUs was conducted with detailed questions on their anti-infectious strategies.

RESULTS

89% (63 of 71) of the Dutch ICUs responded to the online survey. The remaining ICUs were contacted by telephone. 47 (66%) of the Dutch ICUs used SDD, 14 (20%) used SOD and 10 (14%) used neither SDD nor SOD. Within these strategies considerable heterogeneity was observed in the start criteria of SDD/SOD, the regimen adjustments based on microbiological surveillance and the monitoring of the interventions.

CONCLUSIONS

The proportion of Dutch ICUs applying SDD or SOD increased over time. Considerable heterogeneity in the regimens was reported. The impact of the observed differences within SDD and SOD practices on clinical outcome remains to be explored.

An alternative ICU staffing model: implementation of the non-physician provider

INTRODUCTION

Literature in Europe regarding implementation of nurse practitioners or physician assistants in the intensive care unit (ICU) is lacking, while some available studies indicate that this concept can improve the quality of care and overcome physician shortages on ICUs. The aim of this study is to provide insight on how a Dutch ICU implemented non-physician providers (NPP), besides residents, and what this staffing model adds to the care on the ICU.

METHODS

This paper defines the training course and job description of NPPs on a Dutch ICU. It describes the number and quality of invasive interventions performed by NPPs, residents, and intensivists during the years 2015 and 2016. Salary scales of NPPs and residents are provided to describe potential cost-effectiveness.

RESULTS

The tasks of NPPs on the ICU are equal to those of the residents. Analysis of the invasive interventions performed by NPPs showed an incidence of central venous catheter insertion for NPPs of 20 per fulltime equivalent (FTE) and for residents 4.3 per FTE in one year. For arterial catheters the NPP inserted 61.7 per FTE and the residents inserted 11.8 per FTE. The complication rate of both groups was in line with recent literature. Regarding their salary: after five years in service an NPP earns more than a starting resident.

CONCLUSION

This is the first European study which describes the role of NPPs on the ICU and shows that practical interventions normally performed by physicians can be performed with equal safety and quality by NPPs.

Accuracy and reliability of a subcutaneous continuous glucose monitoring device in critically ill patients

Subcutaneous continuous glucose monitoring (CGM) may have benefits in achieving glycemic control in critically ill patients. The aim of this study was to assess the accuracy and reliability of the FreeStyle Navigator I in critically ill patients and to assess patient related factors influencing the accuracy and reliability. This study is a retrospective analysis of data from a randomized controlled trial conducted in a 20-bed mixed intensive care unit. Analytical accuracy, clinical accuracy and reliability were assessed against arterial blood glucose samples as reference. Assessment was according to recent consensus recommendations with median absolute relative difference (median ARD), Bland-Altman plots, the ISO system accuracy standards (ISO 15197:2013) and Clarke error grid analysis (CEG). We analyzed 2840 paired measurements from 155 critically ill patients. The median ARD of all paired values was 13.3 [6.9-22.1]%. The median ARD was significantly higher in both the hypoglycemic and the hyperglycemic range (32.4 [12.1-53.4]% and 18.7 [10.7-28.3]% respectively, p < 0.001). The Bland-Altman analysis showed a mean bias of - 0.82 mmol/L with a lower limit of agreement (LOA) of - 3.88 mmol/L and an upper LOA of 2.24 mmol/L. A total of 1626 (57.3%) values met the ISO-2013, standards and 1,334 (47%) CGM values were within 12.5% from the reference value. CEG: 71.0% zone A, 25.8% zone B, 0.5% zone C, 2.5% zone D, 0.3% zone E. The median overall real-time data display time was 94.0 ± 14.9% and in 23% of the patients, the sensor measured < 95% of the time. Additionally, data gaps longer than 30 min were found in 48% of the patients. The analytical accuracy of the FreeStyle Navigator I in critically ill patients was suboptimal. Furthermore, the clinical accuracy, did not meet the required standards. The reliability was satisfactory, however, in almost a quarter of the patients the realtime data display was < 95%. The accuracy was considerably and significantly lower in hyper- and hypoglycemic ranges.

Trends in practice of blood glucose control in critically ill patients in the Netherlands

BACKGROUND

Publication of the Normoglycemia in Intensive Care Evaluation and Survival Using Glucose Algorithm Regulation (NICE-SUGAR) trial in 2009 and several observational studies caused a change in the recommendations for blood glucose control in intensive care patients. We evaluated local trends in blood glucose control in intensive care units in the Netherlands before and after the publication of the NICE-SUGAR trial and the revised Surviving Sepsis Campaign (SSC) guidelines in 2012.

METHODS

Survey focusing on the timing of changes in thresholds in local guidelines for blood glucose control and interrupted time-series analysis of patients admitted to seven intensive care units in the Netherlands from September 2008 through July 2014. Statistical process control was used to visualise and analyse trends in metrics for blood glucose control in association with the moment changes became effective.

RESULTS

Overall, the mean blood glucose level increased and the median percentage of blood glucose levels within the normoglycaemic range and in the hypoglycaemic range decreased, while the relative proportion of hyperglycaemic measurements increased. Changes in metrics were notable after publication of the NICE-SUGAR trial and the SSC guidelines but more frequent after changes in local guidelines; some changes seemed to appear independent of changes in local guidelines.

CONCLUSION

Local guidelines for blood glucose practice have changed in intensive care units in the Netherlands since the publication of the NICE-SUGAR trial and the revised SSC guidelines. Trends in the metrics for blood glucose control suggest new, higher target ranges for blood glucose control.

Ventilator setting in ICUs: comparing a Dutch with a European cohort

BACKGROUND

From data collected during the third International Study on Mechanical Ventilation (ISMV), we compared data from a Dutch cohort with a European cohort. We hypothesised that tidal volumes were smaller and applied positive end-expiratory pressure (PEEP) was higher in the Netherlands, compared with the European cohort. We also compared use of non-invasive ventilation (NIV) and outcomes in both cohorts.

METHODS

A post-hoc analysis of a prospective observational study of patients receiving mechanical ventilation.

RESULTS

Tidal volumes were smaller (7.6 vs. 8.1 ml÷kg predicted bodyweight) in the Dutch cohort and applied PEEP was higher (8 vs. 6 cm H2O). Fewer patients admitted in the Netherlands received NIV as first mode of mechanical ventilation (7.1 vs. 16.7%). Fewer patients in the Dutch cohort developed an ICU-acquired pneumonia (4.5 vs. 12.3%, p < 0.01) and sepsis (5.7 vs. 10.9%, p = 0.03), but more patients were diagnosed as having delirium (15.8 vs. 4.6%, p < 0.01). ICU and in-hospital mortality rates were 19% and 25%, respectively, in Dutch ICUs vs. 26% and 33% in Europe (p = 0.06 and 0.03).

CONCLUSION

Tidal volumes were smaller and applied PEEP was higher in the Dutch cohort compared with international data, but both Dutch and international patients received larger tidal volumes than recommended for prevention or treatment of acute respiratory distress syndrome. NIV as first mode of mechanical ventilation is less commonly used in the Netherlands. The incidence of ICU-acquired pneumonia is lower and of delirium higher in the Netherlands compared with international data.

Development and validation of PRE-DELIRIC (PREdiction of DELIRium in ICu patients) delirium prediction model for intensive care patients: observational multicentre study

OBJECTIVES

To develop and validate a delirium prediction model for adult intensive care patients and determine its additional value compared with prediction by caregivers.

DESIGN

Observational multicentre study.

SETTING

Five intensive care units in the Netherlands (two university hospitals and three university affiliated teaching hospitals).

PARTICIPANTS

3056 intensive care patients aged 18 years or over.

MAIN OUTCOME MEASURE

Development of delirium (defined as at least one positive delirium screening) during patients' stay in intensive care.

RESULTS

The model was developed using 1613 consecutive intensive care patients in one hospital and temporally validated using 549 patients from the same hospital. For external validation, data were collected from 894 patients in four other hospitals. The prediction (PRE-DELIRIC) model contains 10 risk factors-age, APACHE-II score, admission group, coma, infection, metabolic acidosis, use of sedatives and morphine, urea concentration, and urgent admission. The model had an area under the receiver operating characteristics curve of 0.87 (95% confidence interval 0.85 to 0.89) and 0.86 after bootstrapping. Temporal validation and external validation resulted in areas under the curve of 0.89 (0.86 to 0.92) and 0.84 (0.82 to 0.87). The pooled area under the receiver operating characteristics curve (n=3056) was 0.85 (0.84 to 0.87). The area under the curve for nurses' and physicians' predictions (n=124) was significantly lower at 0.59 (0.49 to 0.70) for both.

CONCLUSION

The PRE-DELIRIC model for intensive care patients consists of 10 risk factors that are readily available within 24 hours after intensive care admission and has a high predictive value. Clinical prediction by nurses and physicians performed significantly worse. The model allows for early prediction of delirium and initiation of preventive measures. Trial registration Clinical trials NCT00604773 (development study) and NCT00961389 (validation study).

The emergency care of cocaine intoxications

Cocaine is frequently used, especially among adolescents and by men between the age of 25 and 44. Many of them are able to use cocaine in normal day-to-day life, without any problems. Reduced prices of cocaine and other recreational drugs such as MDMA (ecstasy) and gamma hydroxybutyrate (GHB) has led to an increased incidence of intoxications with these drugs. Since the production of cocaine is illegal, it may be impure and mixtures with other drugs such as atropine may occur. The treatment of patients with an acute cocaine intoxication can be complicated. Combination of cocaine with other drugs results in clinical pictures which are difficult to discriminate and that may have important consequences for treatment.

4-Aminopyridine (fampridine) effectively treats amlodipine poisoning: a case report

A case of a serious poisoning with the calcium entry blocker amlodipine is described, which was treated effectively with 4-aminopyridine. Calcium is suggested as general treatment of poisoning with calcium entry blockers in many guidelines. The use of intravenous 4-aminopyridine is theoretically useful to treat poisoning from calcium entry blockers and was demonstrated in this case report.

External validation of prognostic models for critically ill patients required substantial sample sizes

OBJECTIVE

To investigate the behavior of predictive performance measures that are commonly used in external validation of prognostic models for outcome at intensive care units (ICUs).

STUDY DESIGN AND SETTING

Four prognostic models (Simplified Acute Physiology Score II, the Acute Physiology and Chronic Health Evaluation II, and the Mortality Probability Models II) were evaluated in the Dutch National Intensive Care Evaluation registry database. For each model discrimination (AUC), accuracy (Brier score), and two calibration measures were assessed on data from 41,239 ICU admissions. This validation procedure was repeated with smaller subsamples randomly drawn from the database, and the results were compared with those obtained on the entire data set.

RESULTS

Differences in performance between the models were small. The AUC and Brier score showed large variation with small samples. Standard errors of AUC values were accurate but the power to detect differences in performance was low. Calibration tests were extremely sensitive to sample size. Direct comparison of performance, without statistical analysis, was unreliable with either measure.

CONCLUSION

Substantial sample sizes are required for performance assessment and model comparison in external validation. Calibration statistics and significance tests should not be used in these settings. Instead, a simple customization method to repair lack-of-fit problems is recommended.

Sublingual microcirculatory flow is impaired by the vasopressin-analogue terlipressin in a patient with catecholamine-resistant septic shock

For many decades arterial blood pressure regulation has been an important issue in the treatment of septic shock. The pathogenesis of this persistent hypotension is complex and multifactorial, but inability of vascular smooth muscle to contract in the presence of vasoconstrictive agents seems to be a key factor. Many mechanisms have been proposed to account for this failure, including nitric oxide (NO) overproduction and vasopressin deficiency (1). However, improvement of outcome due to intervention in these mechanisms fails to be reported despite the restoration of blood pressure. Recent studies of the microcirculation in humans by means of orthogonal polarization spectral (OPS) imaging have opened challenging new perspectives to study the microcirculation (2, 3). We report a case in which sublingual OPS imaging was performed upon administration of terlipressin in a patient with catecholamine-resistant septic shock. It indicates that much caution should be taken when considering such potent vasoconstrictor when correcting blood pressure during shock.

Filter Run Time in CVVH: Pre- versus Post-Dilution and Nadroparin versus Regional Heparin-Protamine Anticoagulation

BACKGROUND/AIMS

To study the effect of different modes of continuous veno-venous haemofiltration (CVVH) on filter run time (FRT).

METHODS

We studied, in two consecutive prospective, randomised and crossover studies, 16 and 15 patients with acute renal failure during critical illness. Study A compared pre- versus post-dilution, and study B compared regional anticoagulation with heparin (pre-filter) and protamine (post-filter) (HP) versus nadroparin (NP) pre-filter. All CVVH sessions were standardised. Analyses were by Wilcoxon rank sum tests.

RESULTS

Study A: During pre-dilution the median FRT was 45.7 vs. 16.1 h in post-dilution CVVH (p = 0.005). The median creatinine clearance during pre-dilution was 33 vs. 45 ml/min in post-dilution (p = 0.001). Study B: During NP, median FRT was 39.5 vs. 12.3 h during HP CVVH (p = 0.045).

CONCLUSIONS

Pre-dilution CVVH results in the greatest FRT but a lower plasma creatinine clearance compared to post-dilution. Regional anticoagulation with heparin-protamine resulted in a significantly shorter FRT compared to systemic NP anticoagulation.

Valproic acid intoxication: sense and non-sense of haemodialysis

INTRODUCTION

Valproic acid is increasingly used in the treatment of epilepsy, and also prescribed for bipolar affective disorders, schizoaffective disorders, schizophrenia and migraine prophylaxis. We describe two case reports involving valproic acid intoxication with ingestion of ethanol.

METHODS

One patient was treated by supportive care, one patient received haemodialysis.

RESULTS

From analysis of plasma concentrations before and during haemodialysis (pre- and post-filter) it is shown that valproic acid can be effectively eliminated by haemodialysis when plasma levels are way above 100 microg/ml. In the literature, plasma protein binding is reported to be around 90% for levels within the therapeutic range. In our patient plasma protein binding was around 50% after treatment with haemodialysis.

CONCLUSION

These findings make haemodialysis in valproic acid intoxication a sensible therapeutic option with increasing efficiency when plasma concentration is high. Furthermore our findings suggest that lowering valproic acid concentrations to a therapeutic level by haemodialysis does not necessarily result in an immediate, simultaneous increase in plasma protein binding of valproic acid.

A before-after Study of Multi-resistance and Cost of Selective Decontamination of the Digestive Tract

BACKGROUND

We compared standard antibiotic use with an antibiotic policy based on selective decontamination of the digestive tract (SDD) for cost and microbiology.

PATIENTS AND METHODS

A 2-year before-after observational study was performed in an 11-bed, mixed medical and surgical intensive care unit (ICU). We included all consecutive patients admitted to the ICU 1 year before and 1 year after institution of SDD (patients admitted within the 2-month SDD run-in period were excluded from analysis). In the year before SDD, 513 patients were treated in the ICU (mean APACHE II 19.5), compared to 529 in the year with SDD (mean APACHE II 19.4).

RESULTS

The duration of mechanical ventilation was shorter in the SDD-treated patients (median 3, interquartile range [IQR] 2-7 days vs median 4 days, IQR 2-10, p = 0.03). The total of ICU variable costs, microbiological costs and antibiotic costs were equal in both episodes: euro 1,171 versus euro 1,168 per patient). Aerobic gram-negative bacilli (AGNB) and multiresistant AGNB were found less frequently in SDD-treated patients, RR 0.37 (95% CI 0.33-0.42) and RR 0.28 (95% CI 0.19-0.42). Multi-resistant AGNB in tracheal secretions and urine more than 72 hours after admission were completely absent in SDD-treated patients.

CONCLUSION

The overall cost per patient treated during an antibiotic policy including SDD was equal to a policy supporting standard antibiotic care. In addition, duration of ventilation decreased and a trend was shown towards a decreased Length of ICU and hospital stay. Less frequently, cultures from organ sites containing AGNB were found during SDD and the number of multi-resistant strains was significantly reduced at organ sites, in particular trachea and urine. Fewer patients were colonized with multi-resistant AGNB but these numbers did not reach statistical significance.