A clinical trial to compare two methods of blood pressure measurement (arterial line & oscillometric cuff) in critically ill patients
- Registration Number
- CTRI/2023/03/050783
- Lead Sponsor
- Dr R Bharatram
- Brief Summary
Referenceblood pressure will be measured invasively using an indwelling arterialcatheter placed in the radial artery or femoral artery.
Ø The arterial catheter transducerwill be zeroed (to atmosphere) and levelled (right atrium).
Ø Fast Flush test will be performed toconfirm optimal damping.With optimal damping, the measured pressureshould come to reflect the biological signal within one or two oscillations.
Ø If not optimally damped,troubleshooting will be done to achieve it. Patient will not be included in thestudy if optimal damping cannot be achieved.
Non-invasiveoscillometric blood pressure measurements will be performed using an upper-armcuff. (contralateral arm when the arterial line is radial).
Ø Arm circumference will be measuredat the midpoint of acromion & olecranon. The correct cuff size will beestimated for each patient. The “ideal†cuff should have a bladder length thatis 80% and a width that is at least 40% of arm circumference (a length-to-widthratio of 2:1)
Ø The cuff will be placed on bareskin.
Ø If there is an error in noninvasiveoscillometric measurement, that measurement is discarded and new measurementwill be taken after atleast 3 minutes.
Thereadings from the monitor (invasive arterial line BP & oscillometric BP)will be noted at the end of oscillometric BP measurement.
Each pairof measurements – invasive and oscillometric (Systolic, Diastolic & MeanArterial Pressures) – will be taken three times at intervals of three minutes.The average will be calculated and considered as the result of the measurement.
Multiplemeasurements (maximum of 3) may be recorded for each patient at random timeintervals(at least 6 hours apart).
The firstmeasurement will be taken within 48 hours of placement of arterial line.
All themeasurements will be taken within 7 days of inclusion in the study.
The dose ofvasopressor(s) infusion will be documented at the time of the blood pressuremeasurement.
Vasoactive-inotropicscore will be calculated for patients on vasopressor(s) &inotrope(s)
Once thesample collection is complete, patients will be categorized based on the medianVasoactive Inotrope Score (VIS) into the following categories for comparison ofblood pressure measurements
Ø No Vasopressors (VIS = 0)
Ø High dose vasopressors (VIS ≥Median)
Ø Low dose vasopressor groups (VIS< Median)
Agreementbetween measurements will be defined according to the Association for theAdvancement of Medical Instrumentation (AAMI) standards (mean of thedifferences of ≤5 mmHg with a SD of ≤8 mmHg)
Measurementswill be compared using Bland-Altman and Error Grid analyses.
- Detailed Description
Not available
Recruitment & Eligibility
- Status
- Completed
- Sex
- All
- Target Recruitment
- 228
All acutely admitted patients of 18 years & older, with an expected ICU stay of at least 24 hours, in whom arterial line has already been placed for medical reasons.
Contraindication to cuff application/inflation (e.g., arm injuries, burns or wounds).
Study & Design
- Study Type
- Observational
- Study Design
- Not specified
- Primary Outcome Measures
Name Time Method To evaluate the agreement between blood pressure measurements obtained with non-invasive oscillometry (test method) and arterial catheter-derived measurements (reference method). The first measurement will be taken within 48 hours of placement of arterial line.
- Secondary Outcome Measures
Name Time Method To compare degree of agreement between two methods separately in patients on high dose vasopressor, low dose vasopressor and patients who are not on vasopressors. All the measurements will be taken within 7 days of inclusion in the study
Trial Locations
- Locations (1)
Apollo Main Hospital
🇮🇳Chennai, TAMIL NADU, India
Apollo Main Hospital🇮🇳Chennai, TAMIL NADU, IndiaDr R BharatramPrincipal investigator9133913000bharatram.iyer@gmail.com