Utilization of Somatic Tissue Oxygen Saturation Monitoring in Pregnant Women

Yale University

Status: Withdrawn

Conditions: Pre-Eclampsia

Treatments: Diagnostic Test: StO2 and EndoPAT

Study type: Interventional

Funder types: Other

Identifiers

NCT03196141

2000020110

Details and patient eligibility

About

The purpose of this study is to compare 3 methods of assessing endothelial function in healthy female volunteers and pregnant women with and without pregnancy induced hypertension. The methods under comparison are simultaneous tissue oxygen saturation (StO2), EndoPAT and Sphygmocor (pregnant women only). 35 participants (15 healthy, 10 pregnant normal blood pressure, 10 pregnant with hypertension) will be enrolled.

Full description

In both normotensive women and others with pregnancy induced hypertension, in previous research simultaneous tissue oxygen saturation (StO2) were measured in both forearms, with a blood pressure cuff above the tissue oximetry probe on one side.

StO2 values were continuously monitored on each side during unilateral blood pressure (BP) cuff inflation (to suprasystolic pressure for 3 min), and then during deflation. Despite similarity in the forearm StO2 decline observed with cuff inflation in all women, the rise following cuff deflation - indicative of reactive hyperemia - appeared reduced in hypertensive patients, suggesting a relationship with impaired endothelial reserve.

Sex: All

Ages: 18+ years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

Non-pregnant group:

1. > 18 years of age
2. Male or female

Pregnant group:

1. > 18 years of age
2. Pregnant women > 20 weeks
3. Diagnosis of Pre-eclampsia characterized as Systolic BP > 140 mmHg, diastolic BP > 90 mmHg after 20 weeks of gestation accompanied by new onset of proteinuria.
4. Normotensive, not meeting criteria in #3

Exclusion criteria

Non-pregnant group:

1. Raynaud's Disease
2. Adhesive tape allergy
3. Recent Myocardial Infarction (< 3 months)
4. Congestive Heart Failure

Pregnant group:

1. Raynaud's Disease
2. Adhesive tape allergy
3. Recent Myocardial Infarction (< 3 months)
4. Congestive Heart Failure
5. Hemodynamically unstable (SBP < 90 mmHg)
6. Fetal distress

Trial design

Primary purpose: Diagnostic

Allocation: Non-Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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0 participants in 3 patient groups

Healthy volunteers

Active Comparator group

Description:

Part#1: 15 healthy volunteers; 2 assessment sessions. Session 1: StO2 vs. EndoPAT Method comparison analysis; both StO2 and EndoPAT will be applied simultaneously \& pulse oximeter probes placed bilaterally on fingers. Baseline readings will be taken for 5 minutes. The blood pressure cuff will be inflated to suprasystolic pressure and StO2 and pulsatile volume changes will be measured by peripheral arterial tonometry, continuous measurement for 3 min and repeated every 10 minutes for 3 sessions. Session 2: This session will occur within 1 week of session 1. This session is to determine the consistency of the response. All probes will be applied as in session 1 and cycles of 10 minutes for 3 sessions will be done. All the measurements in session 1 will be captured in session 2. This will determine inter-day variability. (total time is 53 min).

Treatment:

Diagnostic Test: StO2 and EndoPAT

Pregnant women with normal BP

Active Comparator group

Description:

Part #2: 20 participants, 10 normotensive and 10 pre-eclamptic pregnant women during their visit to labor floor. Session 1: Both StO2 and EndoPAT will be applied simultaneously to the same arm below a BP cuff. Baseline readings will be taken for 5 minutes, the blood pressure cuff will be inflated to suprasystolic pressure StO2 and pulsatile volume changes will be measured by peripheral arterial tonometry, continuous measurement for 3 min and repeated every 10 minutes for 3 sessions. Additionally, vascular stiffness with be measured by SphygmoCor to measure pulse wave velocity (PWV). Participants must also agree to participate OB/GYN biobanking protocol HIC# 1601017004 to be in this study. All participants will have follow-up at 48 hours, including a blood draw, assessment of endothelial function and vascular stiffness.

Treatment:

Diagnostic Test: StO2 and EndoPAT

Pregnant women with high BP

Active Comparator group

Description:

Part #2: 20 participants, 10 normotensive and 10 pre-eclamptic pregnant women during their visit to labor floor. Session 1: Both StO2 and EndoPAT will be applied simultaneously to the same arm below a BP cuff. Baseline readings will be taken for 5 minutes, the blood pressure cuff will be inflated to suprasystolic pressure StO2 and pulsatile volume changes will be measured by peripheral arterial tonometry, continuous measurement for 3 min and repeated every 10 minutes for 3 sessions. Additionally, vascular stiffness with be measured by SphygmoCor to measure pulse wave velocity (PWV). Participants must also agree to participate OB/GYN biobanking protocol HIC# 1601017004 to be in this study. All participants will have follow-up at 48 hours, including a blood draw, assessment of endothelial function and vascular stiffness. Participants with hypertension will be followed in conjunction with routine clinical follow-up at 2, 6 and 12 weeks post-partum.

Treatment:

Diagnostic Test: StO2 and EndoPAT