Validation of Continuous Noninvasive Haemoglobin Monitoring by the Radical 7 Pulse CO-Oximetry Monitor After in Vivo Adjustment.

Study Overview
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Brief Summary
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Continuous haemoglobin determination could improve the outcomes of several patients in risk of bleeding during surgery. An in vivo calibration has been introduced to the device after our team found its need. The uncalilbrated validation of the Masimo Radical 7 continuous haemoglobin monitor has been made in various papers, although it has been compared to point of care devices, thus introducing an error as such point of care devices although validated for haemoglobin determination, are not as accurate as the gold standard. The validation of the gold standard calibrated device has not been described yet. When compared to the accepted gold standard (cyanmethemoglobin method, Coulter), accuracy and precision of the continuous haemoglobin monitor could be good enough to be used interchangeably with the gold standard.

Detailed Description
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Continuous haemoglobin determination could improve the outcomes of several patients in risk of bleeding during surgery. The in vivo calibration has not been adjusted to the gold standard haemoglobin determination in the literature yet. Two blood samples will be withdrawn at the same time from an arterial line, one for the central laboratory and the other one for the POC device. At the same exact time the SpHb measurement will be recorded. At least eight samples are expected per patient. A maximum of 20 samples will be withdrawn per patient. To compare bias, precision and limits of agreement among SpHb, LabHb and COoxHb the Bland Altman method will be used with multiple observations per subject when the true value varies. An error grid analysis will be made to know how it could affect to clinical decision making.

Official Title
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Validation of a Continuous Noninvasive Haemoglobin Determination Monitor (Radical 7 Pulse CO-Oximeter, SpHb) Compared to the Central Laboratory Coulter (LabHb) and a Point of Care (POC) Invasive Cooximeter (COoxHb) After in Vivo Adjustment.

Conditions
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Sphb Haemoglobin in Vivo Validation

Intervention / Treatment
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* Device: Masimo Radical 7


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult patients. Surgery duration of at least two hours. Patients scheduled to surgery under general anaesthesia and muscle relaxation. Radial arterial line needed for blood pressure control or other reason not related to the study. Exclusion Criteria: Radial arterial line not indicated / not possible to place. Sampling difficult or impossible. Need to reposition arterial line arm during surgery. Any illness that could influence the haemoglobin measurement.

Ages Eligible for Study
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Minimum Age: 18 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

| Intervention/Treatment |
| --- |
|Device: Masimo Radical 7|Simultaneous determination of haemoglobin with the continuous haemoglobin monitor, the central lanboratory coulter and a POC:|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Central coulter bias and limits of agreement | Bias and limits of agreement of SpHb compared to the central laboratory coulter | 3 months | 
| Central coulter bias and limits of agreement after in vivo calibration | Bias and limits of agreement of SpHb compared to the central laboratory coulter after in vivo Radical 7 calibration | 3 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| POC Cooximeter bias and limits of agreement | Bias and limits of agreement of SpHb compared to the POC cooximeter | 3 months | 
| POC Cooximeter bias and limits of agreement | Bias and limits of agreement compared to the POC cooximeter after in vivo Radical 7 calibration | 3 months | 
| POC Cooximeter Coulter interchangeability | Bias and limits of agreement of POC Cooximeter Hb determination compared to the central laboratory coulter | 3 months |