Fixed minimum volume resuscitation: Pro

Assessment of the components of fluid balance in patients with septic shock: a prospective observational study

BACKGROUND

The optimal amount for initial fluid resuscitation is still controversial in sepsis and the contribution of non-resuscitation fluids in fluid balance is unclear. We aimed to investigate the main components of fluid intake and fluid balance in both survivors and non-survivor patients with septic shock within the first 72 hours.

METHODS

In this prospective observational study in two intensive care units, we recorded all fluids administered intravenously, orally, or enterally, and losses during specific time intervals from vasopressor initiation: T1 (up to 24 hours), T2 (24 to 48 hours) and T3 (48 to 72 hours). Logistic regression and a mathematical model assessed the association with mortality and the influence of severity of illness.

RESULTS

We included 139 patients. The main components of fluid intake varied across different time intervals, with resuscitation and non-resuscitation fluids such as antimicrobials and maintenance fluids being significant contributors in T1 and nutritional therapy in T2/T3. A positive fluid balance both in T1 and T2 was associated with mortality (p = 0.049; p = 0.003), while nutritional support in T2 was associated with lower mortality (p = 0.040). The association with mortality was not explained by severity of illness scores.

CONCLUSIONS

Non-resuscitation fluids are major contributors to a positive fluid balance within the first 48 hours of resuscitation. A positive fluid balance in the first 24 and 48 hours seems to independently increase the risk of death, while higher amount of nutrition seems protective. This data might inform fluid stewardship strategies aiming to improve outcomes and minimize complications in sepsis.

Incidence, Patient Characteristics, Mode of Drug Delivery, and Outcomes of Septic Shock Patients Treated With Vasopressors in the Arise Trial

INTRODUCTION

To describe the utilization of vasopressors (VP) in patients enrolled in the Australasian Resuscitation In Sepsis Evaluation (ARISE) trial, and to explore the association between time to VP and 90-day mortality.

METHODS

The primary exposure variable was VP use after arrival in the emergency department (ED). Vasoactive agents considered as VP included: norepinephrine, epinephrine, metaraminol, or vasopressin. Time-to-event analysis, multivariable logistic regression, and propensity-matched treatment effects modeling were used to assess the association between time to VP and 90-day mortality.

RESULTS

In total 1,102 of 1,588 patients (69%) in ARISE received VP at any point. The median [interquartile range (IQR)] time from ED presentation to commencing VP was 4.4 [2.7, 7.1] h, and 38% did so prior to central venous access. The median [IQR] volume of intravenous (i.v.) fluid administered prior to commencing VP was 3.1 [2.3, 4.3] L. Increasing age and volume of i.v. fluid therapy were associated with a lower likelihood of commencing VP early (within 4 h of ED presentation), while greater illness severity was associated with a higher likelihood, P < 0.001, respectively. In those who subsequently died within 90 days, the sub-hazard ratio (95% confidence interval) for commencing VP was 1.4 (1.20, 1.68), P < 0.001, adjusted for age, acute physiology and chronic health evaluation II score, study group, inclusion criteria, plasma lactate, i.v. fluid prior to VP, study institution, and site of infection.

DISCUSSION

50% of the ARISE cohort commenced VP within 4.4 h of ED presentation, and many did so prior to central venous access. Earlier initiation of VP was associated with greater crude and adjusted 90-day mortality.

Expert statement for the management of hypovolemia in sepsis

Hypovolemia is frequent in patients with sepsis and may contribute to worse outcome. The management of these patients is impeded by the low quality of the evidence for many of the specific components of the care. In this paper, we discuss recent advances and controversies in this field and give expert statements for the management of hypovolemia in patients with sepsis including triggers and targets for fluid therapy and volumes and types of fluid to be given. Finally, we point to unanswered questions and suggest a roadmap for future research.

REstricted Fluid REsuscitation in Sepsis-associated Hypotension (REFRESH): study protocol for a pilot randomised controlled trial

BACKGROUND

Guidelines recommend an initial intravenous (IV) fluid bolus of 30 ml/kg isotonic crystalloid for patients with sepsis and hypotension. However, there is a lack of evidence from clinical trials to support this. Accumulating observational data suggest harm associated with the injudicious use of fluids in sepsis. There is currently equipoise regarding liberal or restricted fluid-volume resuscitation as first-line treatment for sepsis-related hypotension. A randomised trial comparing these two approaches is, therefore, justified.

METHODS/DESIGN

The REstricted Fluid REsuscitation in Sepsis-associated Hypotension trial (REFRESH) is a multicentre, open-label, randomised, phase II clinical feasibility trial. Participants will be patients presenting to the emergency departments of Australian metropolitan hospitals with suspected sepsis and a systolic blood pressure of < 100 mmHg, persisting after a 1000-ml fluid bolus with isotonic crystalloid. Participants will be randomised to either a second 1000-ml fluid bolus (standard care) or maintenance rate fluid only, with the early commencement of a vasopressor infusion to maintain a mean arterial pressure of > 65 mmHg, if required (restricted fluid). All will receive further protocolised fluid boluses (500 ml or 250 ml, respectively), if required during the 6-h study period. The primary outcome measure is total volume administered in the first 6 h. Secondary outcomes include fluid volume at 24 h, organ support 'free days' to day 28, 90-day mortality, and a range of feasibility and process-of-care measures. Participants will also undergo serial measurement, over the first 24 h, of biomarkers of inflammation, endothelial cell activation and glycocalyx degradation for comparison between the groups.

DISCUSSION

This is the first randomised trial examining fluid volume for initial resuscitation in septic shock in an industrialised country. A pragmatic, open-label design will establish the feasibility of undertaking a large, international, multicentre trial with sufficient power to assess clinical outcomes. The embedded biomarker study aims to provide mechanistic plausibility for a larger trial by defining the effects of fluid volume on markers of systemic inflammation and the vascular endothelium.

TRIAL REGISTRATION

Australia and New Zealand Clinical Trials Registry, ID: ACTRN12616000006448. Registered on 12 January 2016.