Continuous Non-invasive Assessment of Blood Pressure in Bariatric Surgery

University Hospital Schleswig-Holstein (UKSH)

Status

Completed

Conditions

Arterial Blood Pressure

Bariatric Surgery

Treatments

Procedure: baseline alert 2

Procedure: volume bolus substitution

Procedure: passive leg raising

Procedure: baseline in narcosis 1

Procedure: baseline

Procedure: baseline in narcosis 2

Procedure: ATB in narcosis

Procedure: ATB plus capnoperitoneum plus volume bolus substitution

Procedure: ATB plus capnoperitoneum

Procedure: ATB loss of capnoperitoneum

Procedure: start capnoperitoneum

Procedure: baseline alert 1

Procedure: torso position rising 30° at the end

Procedure: torso position rising 30° at the beginning

Procedure: Anti-Trendelenburg-position (ATB)

Study type

Interventional

Funder types

Other

Identifiers

NCT03184285

IN-BAR-02

Details and patient eligibility

About

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 arterial blood pressure in patients undergoing bariatric surgery.

Full description

Comparison between non-invasive discontinuous blood pressure measurement using a sphygomanometric blood pressure cuff, and continuous non-invasive and invasive beat to beat blood pressure measurement methods(Nexfin© and FloTrac©).

Bariatric patients show limitations regarding the conventional monitoring options with ECG derivation, pulse oxymetric oxygen saturation and sphygmomanometric 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 fluid 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 the investigators use the method described 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.

Enrollment

50 patients

Sex

All

Ages

18+ years old

Volunteers

No Healthy Volunteers

Inclusion criteria

Indication for bariatric surgery was made
Classification according to the American Society of Anesthesiologists (ASA) 2-4
Age > 18 years
Elective laparoscopic surgery
Written declaration of consent
Body Mass Index > 30 kg / m²

Exclusion criteria

atrial fibrillation
cardiac arrhythmias
aortic aneurysm > 4,5 cm
Peripheral arterial occlusive desease grade 3-4
age < 18 years
missing or incorrect patient consent form
cognitive or linguistic barriers

Trial design

Primary purpose

Diagnostic

Allocation

N/A

Interventional model

Single Group Assignment

Masking

None (Open label)

50 participants in 1 patient group

bariatric surgery

Experimental group

Description:

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

Treatment: