Effect of Dynamic Arterial Elastance and Assisted Fluid Management Software Guided Resuscitation in Septic Shock: Pilot Study

To investigate the benefit of using the AFM and Eadyn-guided fluid and vasopressor therapy in septic shock resuscitation for mechanically ventilated patients compared with the standard of care. The investigators hypothesize that using the AFM and Eadyn-guided fluid/vasopressor titration in septic shock patients who underwent mechanical ventilation might reduce the time to shock reversal.

Hypotension in the context of an intensive care unit has been associated with a higher risk of death and multiorgan dysfunction. Vascular leakage and systemic vasodilatation are brought on by systemic inflammation from infections. These are the hallmarks of septic shock in which 90% of cases of shock are mostly distributive and hypovolemic. Early vasopressors and fluid therapy are increasingly used at the start of vasodilatory shock resuscitation since this method improves the rate of shock control within 6 hours in septic shock resuscitation. Norepinephrine is the first-line vasopressor for vasodilatory shock. However, resuscitation with an accurate amount of fluid and vasopressor is challenging in clinical practice. Fluid overload and overuse of vasopressors are prevalent and increase mortality. Together with a higher dose of norepinephrine, it may increase the risk of ischemic complications.

A new hemodynamic monitoring device (Hemosphere(R) - Edward Lifescience, California, USA) provides two novel parameters for hemodynamic monitoring: the new device with artificial intelligence developed by a retrospective cohort (used for training) and a prospective (local hospital cohort used for external validation). The feature of Hemosphere(R), including dynamic arterial elastance (Eadyn) and stroke volume change prediction (∆SVpredict) as the assist fluid management (AFM) based on arterial pressure waveform analysis by the monitoring software, was detected in arterial line waveform without any complication of a safety issue.

The ratio of pulse pressure to stroke volume (PP/SV) is defined by dynamic arterial elastance (Eadyn), the reciprocal of compliance within the range of 0.8 to 1.0 is the optimization of arterial load that can predict arterial pressure response to fluid administration and vasopressor weaning. The prediction of the stroke volume changes following the upcoming fluid therapy (∆SVpredict) uses stroke volume variation parameters and closed-loop feedback data, which should be less than 10% to indicate optimal fluid administration. Consequently, this technique offers a useful means of evaluating arterial tone related to preload responsiveness parameters predicting the hemodynamic response to increases in cardiac preload.

However, several studies show the benefit of this tool in perioperative patients, and the evidence on the benefit of using this monitoring to guide septic shock resuscitation is limited. In a previous study, Eadyn can predict a decrease in mean arterial pressure linked to a reduction in norepinephrine dosage. This study aimed to investigate the benefit of using AFM and Eadyn-guided fluid and vasopressor therapy in septic shock resuscitation compared with the standard of care

Eligibility Criteria:
Inclusion Criteria:

* All Thai consecutive patients older than 18 years with a diagnosis of sepsis or septic shock in medical ICU, defined by clinically suspected or confirmed infection and MAP \<65 mmHg according to the criteria of the Surviving Sepsis Campaign 2021(11)with onset of shock in less than 24 hours.
* Already receiving or planning for mechanical ventilation
* Already receiving or planning for arterial catheter placement for invasive arterial pressure monitoring
* All patients will receive an echocardiogram with a cut point of LVEF \> 30% to be included in the study

Exclusion Criteria:

* Active, immediate, life-threatening cardiac arrhythmia, defined as ventricular tachycardia and ventricular fibrillation
* Acute cerebral vascular event, including both acute ischemic stroke or intracranial hemorrhage
* Acute coronary syndrome
* cardiogenic shock, acute heart failure
* Severe asthma exacerbation
* Fluid intolerance: hypoxemia (P:F ratio \< 150)
* Life-threatening gastrointestinal hemorrhage
* Pregnancy
* Requirement for immediate surgery within 2 hours of randomization
* Advanced-stage cancer with predicted survival of less than 6 months
* Oliguric AKI with signs of volume overload

Withdrawal or termination criteria

* The patient and legal representative request for withdrawal
* The attending physician requested a withdrawal