Observational Study to Assess Oxygen Saturation Predictive Power Related to Intradialytic Acute Hypotension

Study Overview
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Brief Summary
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The aim of the present work was to analyze the short-term variability of SO2 during hemodialysis in sessions with and without hypotension to correlate the SO2 variability to hemodynamic instability.

Detailed Description
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During the last 40 years a lot has been achieved in dialysis regarding both monitors safety and membranes overall performances Anyway, intradialytic symptoms still remain a major concern for nephrologists: in particular, hypotension is the most frequent [1]. Intradialytic hemodynamic monitoring systems have been developed to have continuous surveillance of the main hemodynamic variables (heart rate, body temperature, blood pressure itself, cardiac output, ecc…). In a second moment, the further evolution was towards the retroactive control systems, to force some of the variables involved in the genesis of the hemodynamic stability, along a pre-determined, ideal, trend. In this view, various bio-feedback mechanisms have been proposes along the years, for example, to tackle hypovolemia-related hypotension. Their scientific rationale is the control of either blood volume or directly natremia, in order to pilot plasma refilling towards the vascular compartment [2]. Despite the great achievements obtained, the forecasting of acute hypotension during hemodialysis still remains a complex problem, likely involving more than one variable. SO2 can be considered an indirect expression of the hemodynamic stability. Moreover, in dialysis, it has always been regarded as a bio-compatibility marker for membranes [3]. Nowadays, SO2 changes during dialysis are easy to measure with a fully, non-invasive sensor assembled on the arterial line. We planned this study to analyze on a large number of sessions the short-term variability of SO2 during hemodialysis in relationship with hemodynamic tolerance.

Official Title
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Italian Group of Study on the Role of Oxygen Saturation as a Potential Surrogate Marker of Intradialytic Cardiovascular Instability

Conditions
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Acute Intradialytic Hypotension

Intervention / Treatment
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* Device: Hypotension-prone patients


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Dialysis vintage > 6 months Well functioning arterovenous fistula or central venous catheter thrice weekly HD treatment schedule Acute hypotensions in the last month before study start > 20% of sessions Exclusion Criteria: Mental illness life expectancy < 6 months any profiling and/or biofeedback strategies routinely prescribed

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 85 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Hypotension-prone patients<br>The study group included all patients treated with standard HD prone to acute intradialytic hypotension. | Device: Hypotension-prone patients<br>* Hemox optical sensor equips the dialysis monitors used during this trial. It is able to measure continuously, on arterial blood line, oxygen saturation, hematocrit and blood volume reduction.<br>* Other names: Hemox;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| SO2 short-term variability predictive power | SO2 short term variability predictive power was assessed by means of common clinical tests indexes: sensitivity (number of sessions with effective hypotension correctly classified using SO2 standard deviation analysis) specificity (number of sessions without hypotension correctly classified using SO2 standard deviation analysis) | 3 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Central venous catheters subgroup analysis | This analysis was performed, according to the method described in the Primary Outcome section, only on the group of sessions in which a central catheter was used as vascular access. | 3 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Dialysis, Monitoring, Cardiovascular stability, biosignals