Preeclampsia is a disease of pregnancy affecting 3% to 8% of all pregnancies and is a major
cause of maternal and perinatal morbidity and mortality. Characterized by alter placentation
with subsequent release of inflammatory mediators leading to a generalized endothelial
dysfunction. It is now accepted that endothelial dysfunction heralds the clinical
manifestations of preeclampsia.
The side-stream darkfield (SDF) microscopy device emits a 550 nm green light with a depth
region of interest of 500 um. Green light is absorbed by the erythrocytes and appears black.
SDF is a well-known non-invasive tool that can study the microcirculatory changes. It was
used before in many situations especially in sepsis and septic shock patients.
Near-infra-red spectroscopy (NIRS) device, measures the absorbance of near-infra-red (NIR)
light by tissues perfused with oxygenated blood, and is capable of measuring changes in
parenchymal volume tissues. It was used before in many situations (including pregnant
patients) to reflect the tissue oxygenations.
The investigators are planning to use the SDF and NIRS tools to study the microcirculatory
change in preeclamptic subjects and normal pregnant subjects. If these two devices are able
to determine any changes this should stand as a baseline for future studies in this field.
- Consented at the time of enrollment in the study, which will be at hospital admission
- Demographic data, medical history, obstetrical history, prenatal history and delivery
information will be obtained from medical records and the subject
- Proteinuria, Placental weight, BMI, Birth weight and gender, mother smoker or not,
clinical parameter of preeclampsia, and severity of preeclampsia, uterine artery
Doppler results will be collected from medical records .
- SDF and NIRS application will be done once.
Sidestream dark field (SDF)
The side-stream darkfield camera ( CytoCam) will be put under the subjects tongue for 5-10
minutes. Multiple pictures of the small blood vessels will be taken.
Two fields will be selected that included at least 2 arterioles and 2 venules. Arterioles
will be identified as high-flow vessels in which the direction of flow is from larger
diameter vessels to smaller diameter vessels, while the reverse will be true for venules.
Furthermore, arterioles will be distinguished from venules by the difference in erythrocyte
flow velocity, which is substantially higher in arterioles than in venules. At least 2
arterioles and 2 venules will be taken from each captured image sequence to measure the
blood vessel diameter.
The diameter of blood vessels will be determined using image processing software
specifically designed for analysis of the microcirculation. The diameter of microvessels
will be determined by drawing a perpendicular line from one side of the luminal vessel wall
to the other at 3 separate locations. The functional capillary index (FCD) and the
microvascular flow index (MFI) will be calculated as well. The FCD is defined as the total
length of perfused capillaries per mm2. The MFI is used to describe the different flow
velocities in venules in each observation field. This is a reproducible and validated index
based on a semi-quantitative scoring (0=no flow, 1=intermittent flow, 2=sludging flow,
3=continuous flow and 4=high flow) of flow patterns in large (>50 μm), medium (25-50 μm) and
small (10-25 μm, including capillaries) venules. Intermittent flow is characterized by a
discontinuous flow pattern of erythrocytes during systolic heart contraction, which halts
(or even reverses) during the diastolic phase. In sludging flow, individual erythrocytes
have different low continuous velocities and they can be easily distinguished from each
other. Continuous flow is characterized by an uninterrupted, uniform laminar flow pattern of
erythrocytes that still just can be distinguished from each other. With high flow, the
velocity of erythrocytes has exceeded the capture rate of the camera and therefore
individual erythrocytes cannot be traced anymore and appear as a black column of cells.
CytoCam product is registered by the FDA with number D186803 Class1 exempt. This product is
intended to be used for visualization of micro-circulation in tissue in orifices of the
human body which may be non-invasively accessed and cutaneous surfaces.
Near-infra-red spectroscopy (NIRS) Artinis PortaLite with OxySoft softwear Artinis systems
has developed a customizable NIRS device that measures tissue oxygenation saturation (StO2)
of both muscle and brain tissue. This device can be customized in terms of emitter
wavelength (5 are available, all in the NIR range) and configuration (2 emitters each @ 30,
35, and 40 mm from the detector). Critically, unlike most other commercially available NIRS
devices for clinical care, the Artinis device allows exportation of the actual absorbance
waveforms @ 15 Hz sampling rate. Thus, the Artinis PortaLite with OxySoft softwear will be
used for research only, not for clinical care. The NIRS probe will be applied to one of the
patient's thenar muscle and over the patient forehead and tissue oxygenation (TOI) will be
recorded for 5 minutes.
- Age 18 years and older females (10 with diagnosis of preeclampsia and 10 with normal
- planned to deliver at UVA
- gestational diabetes,
- gestational hypertension,
- chronic hypertension,