Non-invasive Cardio-haemodynamic Assessment in Adult Emergency Department Patients with Sepsis

Objective: To explore the potential benefit of non-invasive cardio-haemodynamic variables in the management of sepsis in the Emergency Department (ED) by measuring their changes with normal treatment and their relationship to outcome. Methods: Study 1: Prospective cohort study of a convenience sample of adult ED patients with uncomplicated sepsis. Cardio-haemodynamic parameters were obtained using a Thoracic Electrical Bioimpedance (TEB) device. Study 2: Prospective cohort study of a convenience sample of adult ED patients with severe sepsis / septic shock. Cardiohaemodynamic parameters were obtained using a TEB device, transcutaneous Doppler ultrasound and Near-Infrared Spectroscopy. Measurements for both studies were taken on ED arrival, ED departure and after 24 hours, whilst patients received normal treatment. All patients were followed up for 30 days. Results: 50 patients were enrolled in study 1 and 73 patients in study 2. Septic patients had a significantly higher cardiac output and significantly lower stroke volume and systemic vascular resistance than non-septic ED controls. After 24 hours of normal treatment cardio-haemodynamic parameters of patients with uncomplicated sepsis and survivors from severe sepsis / septic shock began to normalise. In addition, patients with severe sepsis/septic shock had abnormal tissue oxygen saturation on ED arrival, which, in survivors normalised with treatment. Conclusion: This is the first description of cardio-haemodynamic parameters in septic patients at their entry to hospital (ED). Septic patients have initially abnormal haemodynamics and the ability to normalise haemodynamics and tissue oxygen saturation is associated with good outcome. This thesis has identified a number of parameters, which warrant validation to define their role as diagnostic or co-diagnostic biomarkers for sepsis and sepsis outcome.