Conservative Fluid Management After Sepsis Resuscitation: A Pilot Randomized Trial

Behind the scenes: Key lessons learned from the RELIEVE-AKI clinical trial

Continuous kidney replacement therapy (CKRT) is commonly used to manage critically ill patients with severe acute kidney injury. While recent trials focused on the correct dosing and timing of CKRT, our understanding regarding the optimum dose of net ultrafiltration is limited to retrospective data. The Restrictive versus Liberal Rate of Extracorporeal Volume Removal Evaluation in Acute Kidney Injury (RELIEVE-AKI) trial has been conducted to assess the feasibility of a prospective randomized trial in determining the optimum net ultrafiltration rate. This paper outlines the relevant challenges and solutions in implementing this complex ICU-based trial. Several difficulties were encountered, starting with clinical issues related to conducting a trial on patients with rapidly changing hemodynamics, low patient recruitment rates, increased nursing workload, and the enormous volume of data generated by patients undergoing prolonged CKRT. Following several brainstorming sessions, several points were highlighted to be considered, including the need to streamline the intervention, add more flexibility in the trial protocols, ensure comprehensive a priori planning, particularly regarding nursing roles and their compensation, and enhance data management systems. These insights are critical for guiding future ICU-based dynamically titrated intervention trials, leading to more efficient trial management, improved data quality, and enhanced patient safety.

Impact of a Pharmacist-Driven Medication Diluent Volume Optimization Protocol on Fluid Balance and Outcomes in Critically Ill Patients

Background: Volume overload (VO) is common in the intensive care unit (ICU) and associated with negative outcomes. Approaches have been investigated to curtail VO; however, none specifically focused on medication diluent volume optimization. Objective: Investigate the impact of a pharmacist-driven medication diluent volume optimization protocol on fluid balance in critically ill patients. Methods: A prospective, pilot study was conducted in a medical ICU during October 2021 to December 2021 (pre) and February 2022 to April 2022 (post). A pharmacist-driven medication diluent volume optimization protocol focusing on vasopressor and antimicrobial diluent volumes was implemented. Demographics and clinical data were collected during ICU admission up to 7 days. The primary outcome was net fluid balance on day 3. Secondary outcomes were medication volumes administered, net fluid balance, ICU length of stay, and mortality. Results: Supply chain shortages caused the study to stop at the end of February 2022. Overall, 152 patients were included (123 pre group, 29 post group). The most common admission diagnosis was acute respiratory failure (35%). Vasopressors and antimicrobials were utilized in 47% and 66% of patients, respectively. Net fluid balance on day 3 was greater but not significant in the post group (227.1 mL [-1840.3 to 3483.7] vs 2012.3 mL [-2686.0 to 4846.0]; P = .584). Antimicrobial diluent volumes were significantly less in the post group. No differences were seen in other secondary outcomes. Protocol group assignment was not associated with net fluid balance on day 3. Conclusion: Despite decreasing antimicrobial volume contributions, optimizing diluent volumes alone did not significantly impact overall volume status. Future studies should focus on comprehensive approaches to medication diluent optimization and fluid stewardship.

Fluid Management in Acute Respiratory Failure

Fluid management in acute respiratory failure is an area of uncertainty requiring a delicate balance of resuscitation and fluid removal to manage hypoperfusion and avoidance of hypoxemia. Overall, a restrictive fluid strategy (minimizing fluid administration) and careful attention to overall fluid balance may be beneficial after initial resuscitation and does not have major side effects. Further studies are needed to improve our understanding of patients who will benefit from a restrictive or liberal fluid management strategy.

Dose-related effects of norepinephrine on early-stage endotoxemic shock in a swine model

Background

The benefits of early use of norepinephrine in endotoxemic shock remain unknown. We aimed to elucidate the effects of different doses of norepinephrine in early-stage endotoxemic shock using a clinically relevant large animal model.

Methods

Vasodilatory shock was induced by endotoxin bolus in 30 Bama suckling pigs. Treatment included fluid resuscitation and administration of different doses of norepinephrine, to induce return to baseline mean arterial pressure (MAP). Fluid management, hemodynamic, microcirculation, inflammation, and organ function variables were monitored. All animals were supported for 6 h after endotoxemic shock.

Results

Infused fluid volume decreased with increasing norepinephrine dose. Return to baseline MAP was achieved more frequently with doses of 0.8 µg/kg/min and 1.6 µg/kg/min (P <0.01). At the end of the shock resuscitation period, cardiac index was higher in pigs treated with 0.8 µg/kg/min norepinephrine (P <0.01), while systemic vascular resistance was higher in those receiving 0.4 µg/kg/min (P <0.01). Extravascular lung water level and degree of organ edema were higher in animals administered no or 0.2 µg/kg/min norepinephrine (P <0.01), while the percentage of perfused small vessel density (PSVD) was higher in those receiving 0.8 µg/kg/min (P <0.05) and serum lactate was higher in the groups administered no and 1.6 µg/kg/min norepinephrine (P <0.01).

Conclusions

The impact of norepinephrine on the macro- and micro-circulation in early-stage endotoxemic shock is dose-dependent, with very low and very high doses resulting in detrimental effects. Only an appropriate norepinephrine dose was associated with improved tissue perfusion and organ function.

Restrictive Versus Liberal Fluid Regimen in Refractory Sepsis and Septic Shock: A Systematic Review and Meta-Analysis

The optimal fluid management strategy for patients with sepsis remains a topic of debate. This meta-analysis aims to evaluate the impact of restrictive versus liberal fluid regimens on mortality, adverse events, and other clinical outcomes in patients with sepsis. We systematically reviewed 11 randomized controlled trials published between 2008 and 2023, comprising a total of 4,121 participants. The studies assessed 90-day mortality, 30-day mortality, adverse events, hospital length of stay, ICU admission rate, mechanical ventilation, ventilator-free days, ICU-free days, and vasopressor-free days. Quality assessments indicated minimal bias across the studies. The meta-analysis showed no statistically significant difference in 90-day mortality between restrictive and liberal fluid regimens (OR, 0.93; 95% CI, 0.80 to 1.70; P=0.30). Similar results were observed for 30-day mortality (OR, 0.73; 95% CI, 0.30 to 1.80; P=0.50). Adverse events were comparable between the two groups (OR, 0.81; 95% CI, 0.55 to 1.19; P=0.28). Furthermore, there were no significant differences in hospital length of stay (OR, 0.47; 95% CI, -0.85 to 1.80; P=0.48) or ICU admission rate (OR, 1.09; 95% CI, 0.66 to 1.77; P=0.75) between the restrictive and liberal fluid regimens. Regarding mechanical ventilation and ventilator-free days, no significant distinctions were observed (OR, 0.87; 95% CI, 0.65 to 1.17; P=0.48; OR, 0.99; 95% CI, -0.17 to 2.15; P=0.09, respectively). ICU-free days and vasopressor-free days also showed no significant differences between the two groups (OR, 0.97; 95% CI, -0.28 to 2.21; P=0.13; OR, -0.38; 95% CI, -1.14 to 0.37; P=0.32, respectively). This comprehensive meta-analysis of clinical trials suggests that restrictive and liberal fluid management strategies have comparable outcomes in patients with sepsis, including mortality, adverse events, and various clinical parameters. However, most studies favored restrictive fluid regimen over liberal approach regarding the number of vasopressor-free days, need for mechanical ventilation, adverse events, 30-day mortality, and 90-day mortality in sepsis patients.

Lower vs Higher Fluid Volumes in Adult Patients With Sepsis: An Updated Systematic Review With Meta-Analysis and Trial Sequential Analysis

BACKGROUND

IV fluids are recommended for adults with sepsis. However, the optimal strategy for IV fluid management in sepsis is unknown, and clinical equipoise exists.

RESEARCH QUESTION

Do lower vs higher fluid volumes improve patient-important outcomes in adult patients with sepsis?

STUDY DESIGN AND METHODS

We updated a systematic review with meta-analysis and trial sequential analysis of randomized clinical trials assessing lower vs higher IV fluid volumes in adult patients with sepsis. The coprimary outcomes were all-cause mortality, serious adverse events, and health-related quality of life. We followed the recommendations from the Cochrane Handbook and used the Grading of Recommendations Assessment, Development and Evaluation approach. Primary conclusions were based on trials with low risk of bias if available.

RESULTS

We included 13 trials (N = 4,006) with four trials (n = 3,385) added to this update. The meta-analysis of all-cause mortality in eight trials with low risk of bias showed a relative risk of 0.99 (97% CI, 0.89-1.10; moderate certainty evidence). Six trials with predefined definitions of serious adverse events showed a relative risk of 0.95 (97% CI, 0.83-1.07; low certainty evidence). Health-related quality of life was not reported.

INTERPRETATION

Among adult patients with sepsis, lower IV fluid volumes probably result in little to no difference in all-cause mortality compared with higher IV fluid volumes, but the interpretation is limited by imprecision in the estimate, which does not exclude potential benefit or harm. Similarly, the evidence suggests lower IV fluid volumes result in little to no difference in serious adverse events. No trials reported on health-related quality of life.

TRIAL REGISTRATION

PROSPERO; No.: CRD42022312572; URL: https://www.crd.york.ac.uk/prospero/.

Evolving Management Practices for Early Sepsis-induced Hypoperfusion: A Narrative Review

Sepsis causes significant morbidity and mortality worldwide. Resuscitation is a cornerstone of management. This review covers five areas of evolving practice in the management of early sepsis-induced hypoperfusion: fluid resuscitation volume, timing of vasopressor initiation, resuscitation targets, route of vasopressor administration, and use of invasive blood pressure monitoring. For each topic, we review the seminal evidence, discuss the evolution of practice over time, and highlight questions for additional research. Intravenous fluids are a core component of early sepsis resuscitation. However, with growing concerns about the harms of fluid, practice is evolving toward smaller-volume resuscitation, which is often paired with earlier vasopressor initiation. Large trials of fluid-restrictive, vasopressor-early strategies are providing more information about the safety and potential benefit of these approaches. Lowering blood pressure targets is a means to prevent fluid overload and reduce exposure to vasopressors; mean arterial pressure targets of 60-65 mm Hg appear to be safe, at least in older patients. With the trend toward earlier vasopressor initiation, the need for central administration of vasopressors has been questioned, and peripheral vasopressor use is increasing, although it is not universally accepted. Similarly, although guidelines suggest the use of invasive blood pressure monitoring with arterial catheters in patients receiving vasopressors, blood pressure cuffs are less invasive and often sufficient. Overall, the management of early sepsis-induced hypoperfusion is evolving toward fluid-sparing and less-invasive strategies. However, many questions remain, and additional data are needed to further optimize our approach to resuscitation.

Active fluid de-resuscitation in critically ill patients with septic shock: A systematic review and meta-analysis

PURPOSE

To evaluate the impact of active fluid de-resuscitation on mortality in critically ill patients with septic shock.

METHODS

A systematic search was performed on PubMed, EmBase, and the Cochrane Library databases. Trials investigating active fluid de-resuscitation and reporting data on mortality in patients with septic shock were eligible. The primary objective was the impact of active de-resuscitation in patients with septic shock on short-term mortality. Secondary outcomes were whether de-resuscitation lead to a fluid separation, and the impact of de-resuscitation on patient-centred outcomes.

RESULTS

Thirteen trials (8,030 patients) were included in the systematic review, whereof 5 randomised-controlled trials (RCTs) were included in the meta-analysis. None of the RCTs showed a reduction in mortality with active de-resuscitation measures (relative risk (RR) 1.12 [95%-CI 0.84 - 1.48]). Fluid separation was achieved by two RCTs. Evidence from non-randomised trials suggests a mortality benefit with de-resuscitation strategies and indicates a trend towards a more negative fluid balance. Patient-centred outcomes were not influenced in the RCTs, and only one non-randomised trial revealed an impact on the duration of mechanical ventilation and renal replacement requirement (RRT).

CONCLUSION

We found no evidence for superiority of active fluid de-resuscitation compared to usual care regarding mortality, fluid balance or patient-centred outcomes in patients with septic shock. Current evidence is limited by the lack of high-quality RCTs in patients with septic shock, the small sample sizes and the heterogeneity of the applied de-resuscitation techniques. In addition, validity of the majority of RCTs is compromised by their inability to achieve fluid separation.

Evidence-based updates to the 2021 Surviving Sepsis Campaign guidelines Part 2: Guideline review and clinical application

ABSTRACT

NPs should be prepared to screen for sepsis, initiate treatment, and optimize care for sepsis survivors. The 2021 Surviving Sepsis Campaign guidelines offer best practices for identification and management of sepsis and septic shock. This article, second in a 2-part series, presents evidence updates and discusses implications for NPs.

Pathophysiology, mechanisms, and managements of tissue hypoxia

Oxygen is needed to generate aerobic adenosine triphosphate and energy that is required to support vital cellular functions. Oxygen delivery (DO₂) to the tissues is determined by convective and diffusive processes. The ability of the body to adjust oxygen extraction (ERO₂) in response to changes in DO₂ is crucial to maintain constant tissue oxygen consumption (VO₂). The capability to increase ERO₂ is the result of the regulation of the circulation and the effects of the simultaneous activation of both central and local factors. The endothelium plays a crucial role in matching tissue oxygen supply to demand in situations of acute drop in tissue oxygenation. Tissue oxygenation is adequate when tissue oxygen demand is met. When DO₂ is severely compromised, a critical DO₂ value is reached below which VO₂ falls and becomes dependent on DO₂, resulting in tissue hypoxia. The different mechanisms of tissue hypoxia are circulatory, anaemic, and hypoxic, characterised by a diminished DO₂ but preserved capacity of increasing ERO₂. Cytopathic hypoxia is another mechanism of tissue hypoxia that is due to impairment in mitochondrial respiration that can be observed in septic conditions with normal overall DO₂. Sepsis induces microcirculatory alterations with decreased functional capillary density, increased number of stopped-flow capillaries, and marked heterogeneity between the areas with large intercapillary distance, resulting in impairment of the tissue to extract oxygen and to satisfy the increased tissue oxygen demand, leading to the development of tissue hypoxia. Different therapeutic approaches exist to increase DO₂ and improve microcirculation, such as fluid therapy, transfusion, vasopressors, inotropes, and vasodilators. However, the effects of these agents on microcirculation are quite variable.

Impact of Clinician Recognition of Acute Respiratory Distress Syndrome on Evidenced-Based Interventions in the Medical ICU

Acute respiratory distress syndrome is underrecognized in the ICU, but it remains uncertain if acute respiratory distress syndrome recognition affects evidence-based acute respiratory distress syndrome care in the modern era. We sought to determine the rate of clinician-recognized acute respiratory distress syndrome in an academic medical ICU and understand how clinician-recognized-acute respiratory distress syndrome affects clinical care and patient-centered outcomes.

DESIGN

Observational cohort study.

SETTING

Single medical ICU at an academic tertiary-care hospital.

PATIENTS

Nine hundred seventy-seven critically ill adults (381 with expert-adjudicated acute respiratory distress syndrome) enrolled from 2006 to 2015.

INTERVENTIONS

Clinician-recognized-acute respiratory distress syndrome was identified using an electronic keyword search of clinical notes in the electronic health record. We assessed the classification performance of clinician-recognized acute respiratory distress syndrome for identifying expert-adjudicated acute respiratory distress syndrome. We also compared differences in ventilator settings, diuretic prescriptions, and cumulative fluid balance between clinician-recognized acute respiratory distress syndrome and unrecognized acute respiratory distress syndrome.

MEASUREMENTS AND MAIN RESULTS

Overall, clinician-recognized-acute respiratory distress syndrome had a sensitivity of 47.5%, specificity 91.1%, positive predictive value 77.4%, and negative predictive value 73.1% for expert-adjudicated acute respiratory distress syndrome. Among the 381 expert-adjudicated acute respiratory distress syndrome cases, we did not observe any differences in ventilator tidal volumes between clinician-recognized-acute respiratory distress syndrome and unrecognized acute respiratory distress syndrome, but clinician-recognized-acute respiratory distress syndrome patients had a more negative cumulative fluid balance (mean difference, -781 mL; 95% CI, [-1,846 to +283]) and were more likely to receive diuretics (49.3% vs 35.7%, p = 0.02). There were no differences in mortality, ICU length of stay, or ventilator-free days.

CONCLUSIONS

Acute respiratory distress syndrome recognition was low in this single-center study. Although acute respiratory distress syndrome recognition was not associated with lower ventilator volumes, it was associated with differences in behaviors related to fluid management. These findings have implications for the design of future studies promoting evidence-based acute respiratory distress syndrome interventions in the ICU.

Restrictive fluid management versus usual care in acute kidney injury (REVERSE-AKI): a pilot randomized controlled feasibility trial

Purpose

We compared a restrictive fluid management strategy to usual care among critically ill patients with acute kidney injury (AKI) who had received initial fluid resuscitation.

Methods

This multicenter feasibility trial randomized 100 AKI patients 1:1 in seven ICUs in Europe and Australia. Restrictive fluid management included targeting negative or neutral daily fluid balance by minimizing fluid input and/or enhancing urine output with diuretics administered at the discretion of the clinician. Fluid boluses were administered as clinically indicated. The primary endpoint was cumulative fluid balance 72 h from randomization.

Results

Mean (SD) cumulative fluid balance at 72 h from randomization was − 1080 mL (2003 mL) in the restrictive fluid management arm and 61 mL (3131 mL) in the usual care arm, mean difference (95% CI) − 1148 mL (− 2200 to − 96) mL, P = 0.033. Median [IQR] duration of AKI was 2 [1–3] and 3 [2–7] days, respectively (median difference − 1.0 [− 3.0 to 0.0], P = 0.071). Altogether, 6 out of 46 (13%) patients in the restrictive fluid management arm and 15 out of 50 (30%) in the usual care arm received renal replacement therapy (RR 0.42; 95% CI 0.16–0.91), P = 0.043. Cumulative fluid balance at 24 h and 7 days was lower in the restrictive fluid management arm. The dose of diuretics was not different between the groups. Adverse events occurred more frequently in the usual care arm.

Conclusions

In critically ill patients with AKI, a restrictive fluid management regimen resulted in lower cumulative fluid balance and less adverse events compared to usual care. Larger trials of this intervention are justified.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00134-021-06401-6.

Characteristics of resuscitation, and association between use of dynamic tests of fluid responsiveness and outcomes in septic patients: results of a multicenter prospective cohort study in Argentina

BACKGROUND

Resuscitation of septic patients regarding goals, monitoring aspects and therapy is highly variable. Our aim was to characterize cardiovascular and fluid management of sepsis in Argentina, a low and middle-income country (LMIC). Furthermore, we sought to test whether the utilization of dynamic tests of fluid responsiveness, as a guide for fluid therapy after initial resuscitation in patients with persistent or recurrent hypoperfusion, was associated with decreased mortality.

METHODS

Secondary analysis of a national, multicenter prospective cohort study (n = 787) fulfilling Sepsis-3 definitions. Epidemiological characteristics, hemodynamic management data, type of fluids and vasopressors administered, physiological variables denoting hypoperfusion, use of tests of fluid responsiveness, and outcomes, were registered. Independent predictors of mortality were identified with logistic regression analysis.

RESULTS

Initially, 584 of 787 patients (74%) had mean arterial pressure (MAP) < 65 mm Hg and/or signs of hypoperfusion and received 30 mL/kg of fluids, mostly normal saline (53%) and Ringer lactate (35%). Vasopressors and/or inotropes were administered in 514 (65%) patients, mainly norepinephrine (100%) and dobutamine (9%); in 22%, vasopressors were administered before ending the fluid load. After this, 413 patients (53%) presented persisting or recurrent hypotension and/or hypoperfusion, which prompted administration of additional fluid, based on: lactate levels (66%), urine output (62%), heart rate (54%), central venous O₂ saturation (39%), central venous-arterial PCO₂ difference (38%), MAP (31%), dynamic tests of fluid responsiveness (30%), capillary-refill time (28%), mottling (26%), central venous pressure (24%), cardiac index (13%) and/or pulmonary wedge pressure (3%). Independent predictors of mortality were SOFA and Charlson scores, lactate, requirement of mechanical ventilation, and utilization of dynamic tests of fluid responsiveness.

CONCLUSIONS

In this prospective observational study assessing the characteristics of resuscitation of septic patients in Argentina, a LMIC, the prevalent use of initial fluid bolus with normal saline and Ringer lactate and the use of norepinephrine as the most frequent vasopressor, reflect current worldwide practices. After initial resuscitation with 30 mL/kg of fluids and vasopressors, 413 patients developed persistent or recurrent hypoperfusion, which required further volume expansion. In this setting, the assessment of fluid responsiveness with dynamic tests to guide fluid resuscitation was independently associated with decreased mortality.

Lower vs Higher Fluid Volumes During Initial Management of Sepsis: A Systematic Review With Meta-Analysis and Trial Sequential Analysis

OBJECTIVE

IV fluids are recommended during the initial management of sepsis, but the quality of evidence is low, and clinical equipoise exists. We aimed to assess patient-important benefits and harms of lower vs higher fluid volumes in adult patients with sepsis.

METHODS

We conducted a systematic review with meta-analysis and trial sequential analysis (TSA) of randomized clinical trials of IV fluid volume separation in adult patients with sepsis. We adhered to our published protocol; the Cochrane handbook; the Preferred Reporting Items for Systematic Reviews and Meta-Analyses; and the Grading of Recommendations Assessment, Development and Evaluation statements. The primary outcomes were all-cause mortality, serious adverse events (SAEs), and quality of life.

RESULTS

We included nine trials (n = 637); all were published after 2015 and had an overall high risk of bias. We found no statistically significant difference between lower vs higher fluid volumes in all-cause mortality (relative risk [RR], 0.87; 95% CI, 0.69-1.10; I² = 0%; TSA-adjusted CI, 0.34-2.22) or SAEs (RR, 0.91; 95% CI, 0.78-1.05; I² = 0%; TSA-adjusted CI, 0.68-1.21). No trials reported on quality of life. We did not find differences in the secondary or exploratory outcomes. The quality of evidence was very low across all outcomes.

CONCLUSIONS

In this systematic review, we found very low quantity and quality of evidence supporting the decision on the volumes of IV fluid therapy in adults with sepsis.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT03668236; URL: www.clinicaltrials.gov.