Physiological and clinical outcomes associated with fluid bolus therapy administered at rapid response calls for hypotension; A retrospective observational study

Author: Sarah Doherty

Doherty, Sarah, 2017 Physiological and clinical outcomes associated with fluid bolus therapy administered at rapid response calls for hypotension; A retrospective observational study, Flinders University, School of Nursing & Midwifery

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Abstract

Introduction: Administration of intravenous (IV) fluid bolus (FB) to hospitalised patients with hypotension is accepted as standard care. However, there is limited evidence that IV FB benefits patients, and it may cause harm.

Study Objectives: To evaluate current practice, physiological response and clinical outcomes associated with administration of IV FB to hypotensive patients during Rapid Response Team (RRT) review.

Methods: An exploratory, single centre, retrospective cohort study conducted over one year and including all patients triggering RRT review for systolic blood pressure (SBP) <90mmHg. Accordingly, to preexisting literature physiological ‘response’ to IV FB was determined as a

SBP increment ≥20%. Clinical outcomes of interest were recurrent RRT for hypotension and ICU admission within 24h. Variables significant on univariate analysis (P<0.05) were incorporated into logistic regression model.

Results: Of 992 RRT reviews for hypotension IV FB was administered to 785(79%) patients (mean age 70(55-83)y; baseline SBP 84(78-90)mmHg; heart rate 80(68-93)bpm). ‘Response’ to FB occurred in 301(42%) patients. Responders to FB were older (OR of response for every 10-year increase in age: 1.15; 95%CI1.04-1.26) and had lower SBP (OR of response for every10mmHg increase in SBP: 0.33; 95%CI0.27-0.41). Regarding clinical outcomes 56/804 (7%) patients were admitted to ICU and 104/804(13%) had subsequent RRT call(s) for hypotension. The FB volume was predictive for ICU admission such that for every additional 500mls the odds of admission to ICU increased by 30% risk (OR1.30; 95%CI1.06-1.60).

Conclusion(s): From this sample of RRT review for hypotension IV FB is frequently administered but physiological response occurs in less than half of patients. Furthermore, the greater FB volume administered increased the risk for ICU admission. Accordingly, the effectiveness of IV FB during RRT review requires further investigation.

Keywords: Fluid bolus therapy, fluid responsiveness

Subject: Nursing thesis

Thesis type: Masters
Completed: 2017
School: School of Nursing & Midwifery
Supervisor: Di Chamberlain