Utilization of Somatic Tissue Oxygen Saturation Monitoring in Pregnant Women

Perioperative Clinical Utilization of Somatic Tissue Oxygen Saturation Monitoring in Pregnant Women

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.

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.

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