Non-invasive Assessment of Cardiac Output and Fluid Responsiveness in Bariatric Surgery
Study Details
Study Description
Brief Summary
Comparability of discontinuous non-invasive (sphygomanometric) and continuous semi-invasive and invasive (Masimo©; Nexfin© Monitoring ; FloTrac © Edwards Lifesciences) beat to beat measurement methods for the determination of cardiac output and fluid responsiveness in patients undergoing bariatric surgery.
| Condition or Disease | Intervention/Treatment | Phase |
|---|---|---|
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N/A |
Detailed Description
Comparability of discontinuous non-invasive (sphygomanometric) and continuous semi-invasive and invasive (Masimo©; Nexfin© Monitoring ; FloTrac © Edwards Lifesciences) beat to beat measurement methods for the determination of cardiac output and fluid responsiveness in patients undergoing bariatric surgery.
Bariatric patients show limitations regarding the conventional monitoring options with ECG derivation, pulse oxymetric oxygen saturation and sphygmo-manometric blood pressure measurement. From a clinical point of view this results in an invasive arterial blood pressure monitoring. In addition to that, intraoperative extreme changes of the patients position on the table combined with the applied pneumoperitoneum during the minimally invasive laparoscopic surgery can significantly influence the cardiovascular parameters. An invasive arterial blood pressure monitoring is able to reproduce the blood pressure by stroke, but it does not give any information about the cardiac output. The sphygmomanometric blood pressure measurement also entails the risk of insufficient detection of a hypotonic phase in the measurement. Additional monitoring systems are currently available, which are capable of measuring completely non-invasive or semi-invasively different cardiovascular parameters such as cardiac output (CO) and volume responsiveness. In this study, the investigators will compare continuous and discontinuous cardiovascular monitoring procedures and their parameters. The measurements take place at specific times, under defined changes in the body position with the additional influence of the pneumoperitoneum.
These changes are recorded and compared at the same time during different measuring methods preoperatively, intraoperatively and postoperatively. The non-invasive Nexfin © Monitoring (Edwards Lifesciences) is to be evaluated and compared with further measurement methods (FloTrac © (Edwards Lifesciences)) as well as the sphygmomanometric upper arm blood pressure measurement. The investigators also compare the non-invasive and invasive continuous beat to beat blood pressure measurement with conventional, discontinuous sphygomanometric upper arm blood pressure measurement.
The planned study is the comparison of 3 different hemodynamic monitoring procedures. For the evaluation we use the method used by Bland and Altmann for calculating the mean deviation (bias) and the precision (mean value ± 2 standard deviations. In the case of multiple measurements , the modification of the Bland-Altman method is applied (repeated measurements). The number of cases was determined with n = 60 patients, followed by an intermediate evaluation. For a Bland-Altman analysis, the width w of the confidence interval for the Limits of Agreement is calculated as w = 6.79 • σ • 1 / √n, where n is number of cases and σ is the standard deviation. For a case count of n = 60, the result is w = 0.88 • σ and thus for this explorative study a sufficiently large number. In case of the dynamic variables, the percentage matching and the calculation of the kappa index are also used for the statistical evaluation.
Study Design
Arms and Interventions
| Arm | Intervention/Treatment |
|---|---|
| Experimental: bariatric surgery baseline alert 1; Anti-Trendelenburg-position (ATB); Anti-Trendelenburg-position (ATB) in narcosis; baseline in narcosis 1; passive leg raising; volume bolus substitution (15 ml/kgKG Sterofundin balanced solution); baseline in narcosis 2; start capnoperitoneum; Anti-Trendelenburg-position (ATB) plus capnoperitoneum; ATB plus capnoperitoneum plus volume bolus substitution (15 ml/kgKG Sterofundin balanced solution); ATB loss of capnoperitoneum; baseline in narcosis; baseline alert 2; torso position rising 30° at the beginning; torso position rising 30° at the end |
Procedure: baseline alert 1
measurement in supine position
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Procedure: Anti-Trendelenburg-position (ATB)
measurement under ATB
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Procedure: ATB in narcosis
measurement under ATB in narcosis
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Procedure: baseline in narcosis 1
measurement in supine position in narcosis
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Procedure: passive leg raising
measurement under passive leg raising
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Procedure: volume bolus substitution
measurement in supine position after volume bolus (15 ml/kgKG Sterofundin balanced solution intravenous)
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Procedure: baseline in narcosis 2
measurement in supine position
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Procedure: start capnoperitoneum
measurement in supine position
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Procedure: ATB plus capnoperitoneum
measurement under ATB plus capnoperitoneum
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Procedure: ATB plus capnoperitoneum plus volume bolus substitution
measurement in ATB plus capnoperitoneum after volume bolus (15 ml/kgKG Sterofundin balanced solution intravenous)
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Procedure: ATB loss of capnoperitoneum
measurement under ATB
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Procedure: baseline
measurement in supine position
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Procedure: baseline alert 2
measurement in supine position
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Procedure: torso position rising 30° at the beginning
measurement in the recovery unit
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Procedure: torso position rising 30° at the end
measurement in the recovery unit
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Outcome Measures
Primary Outcome Measures
- Non-invasive cardiac output, i.e. stroke volume measurement using Nexfin technology [From the beginning of surgery to admission to the PACU, approximately 4 hours]
Accuracy of non-invasive assessment of cardiac output, i.e. stroke volume index in comparison to an invasive standard using FloTrac Vigileo technology
Secondary Outcome Measures
- Non-invasive assessment of fluid responsiveness using Nexfin technology [From the beginning of surgery to admission to the PACU, approximately 4 hours]
Accuracy of non-invasive assessment of fluid responsiveness (PPV, SVV) in comparison to an invasive standard using FloTrac Vigileo technology
Eligibility Criteria
Criteria
Inclusion Criteria:
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Indication for bariatric surgery was made
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Classification according to the American Society of Anesthesiologists (ASA) 2-4
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Age > 18 years
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Elective laparoscopic surgery
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Written declaration of consent
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Body Mass Index > 30 kg / m²
Exclusion Criteria:
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atrial fibrillation
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cardiac arrhythmias
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aortic aneurysm > 4,5 cm
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Peripheral arterial occlusive desease grade 3-4
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age < 18 years
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missing or incorrect patient consent form
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cognitive or linguistic barriers
Contacts and Locations
Locations
| Site | City | State | Country | Postal Code | |
|---|---|---|---|---|---|
| 1 | Universitätsklinikum Schleswig-Holstein Campus Kiel - Klinik für Anästhesiologie und Operative Intensivmedizin | Kiel | Deutschland (DEU) | Germany | 24105 |
Sponsors and Collaborators
- University Hospital Schleswig-Holstein
Investigators
None specified.Study Documents (Full-Text)
None provided.More Information
Publications
None provided.- IN-BAR-01