Existing fluid responsiveness studies using the mini-fluid challenge may be misleading:Methodological considerations and simulations

BACKGROUND: The mini-fluid challenge (MFC) is a clinical concept of predicting fluid responsiveness by rapidly infusing a small amount of intravenous fluids, typically 100 ml, and systematically assessing its haemodynamic effect. The MFC method is meant to predict if a patient will respond to a subsequent, larger fluid challenge, typically another 400 ml, with a significant increase in stroke volume. METHODS: We critically evaluated the general methodology of MFC studies, with statistical considerations, secondary analysis of an existing study, and simulations. RESULTS: Secondary analysis of an existing study showed that the MFC could predict the total fluid response (MFC + 400 ml) with an area under the receiver operator characteristics curve (AUROC) of 0.92, but that the prediction was worse than random for the response to the remaining 400 ml (AUROC = 0.33). In a null simulation with no response to both the MFC and the subsequent fluid challenge, the commonly used analysis could predict fluid responsiveness with an AUROC of 0.73. CONCLUSION: Many existing MFC studies are likely overestimating the classification accuracy of the MFC. This should be considered before adopting the MFC into clinical practice. A better study design includes a second, independent measurement of stroke volume after the MFC. This measurement serves as reference for the response to the subsequent fluid challenge

Individualised perioperative blood pressure and fluid therapy in oesophagectomy:study protocol for a randomised clinical trial

INTRODUCTION: Oesophagectomy is the mainstay of curative treatment for oesophageal cancer, but it is associated with a high risk of major complications. Goal-directed fluid therapy and individualised blood pressure management may prevent complications after surgery. Extending goal-directed fluid therapy after surgery and applying an individual blood pressure target may have substantial benefit in oesophagectomy. This is a protocol for a clinical trial implementing a novel haemodynamic protocol from the start of anaesthesia to the next day with the patient’s own night-time blood pressure as the lower threshold.METHODS: This is a single-centre, single-blind, randomised, clinical trial. Oesophagectomy patients are randomised 1:1 for either perioperative haemodynamic management according to a goal-directed fluid therapy protocol with an individual target blood pressure or for standard care. The primary endpoint is the total burden of morbidity and mortality assessed by the Comprehensive Complication Index 30 days after surgery. Secondary endpoints are complications, reoperations, fluid and vasopressor dosage and quality of life at 90 days after surgery.CONCLUSIONS: The results from this trial provide an objective and easy-to-follow algorithm for fluid administration, which may improve patient-centred outcomes in oesophagectomy patients.</p