Pregnancy
Conditions
Keywords
Microcirculation, Sidestream Dark Field (SDF) Imaging, Spinal Anesthesia, Phenylephrine
Brief summary
This is a study of pregnant women undergoing a cesarean delivery. It will compare their microcirculation before and after the anesthetic. Microcirculation means blood flow to the extremely small blood vessels in the body. It will also look at the differences in microcirculation of participants who receive an infusion of phenylephrine compared to participants who don't. The investigators hypothesize that spinal anesthesia will reduce the vascular density and proportion of perfused vessels.
Interventions
DEVICEInitial MicroScan® (Microvision Medical) SDF Measurement
Initial SDF measurements are recorded in the obstetric preoperative area within two hours prior to administration of spinal anesthesia.
DRUGSpinal Anesthesia- Bupivacaine
The spinal anesthetic technique is standardized. In the operating room spinal anesthesia will be administered with the L2-L5 interspaces in the sitting position using 12 mg of hyperbaric bupivacaine with 15 mcg of fentanyl and 150 mcg of preservative free morphine.
DEVICEComparative MicroScan® (Microvision Medical) SDF Measurement
A second comparative SDF measurement be recorded within 10 minutes after induction of spinal anesthesia.
DRUGBolus Phenylephrine/Ephedrine Treatment
Participants who experience hypotension following induction of spinal anesthesia will be treated with a bolus of phenylephrine and/or ephedrine as needed.
Participants will have an infusion of phenylephrine started immediately following the induction of spinal anesthesia for prevention of hypotension.
Sponsors
IWK Health Centre
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
FEMALE
Age
18 Years to 45 Years
Healthy volunteers
No
Inclusion criteria
* American Society of Anesthesiologists (ASA) Physical Status I-II (ASA I - Healthy, ASA II - mild and controlled systemic disease) * Singleton pregnancies * 36-42 weeks gestation * Non-labouring * Scheduled cesarean delivery * English speaking * Age 18-45 years
Exclusion criteria
* Cardiovascular disease * Hypertensive disease of pregnancy (i.e. mild & severe preeclampsia) * Allergy to phenylephrine, or any other standardized medication * Obesity (BMI \> 35 kg/m2) * Diabetes Mellitus type 1 * Smoker * Coffee/Caffeine intake within 6 hours of SDF measurement
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Microvascular Flow Index (MFI) | Immediately prior to, and within 10 minutes of induction of spinal anesthesia | The change in MFI of participants; measured immediately prior to, and within 10 minutes following the induction of spinal anesthesia |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Microvascular Flow Index (MFI) | Immediately prior to, and within 10 minutes of induction of spinal anesthesia | The difference between the MFI measured within 10 minutes following the induction of spinal anesthesia in participants who receive phenylephrine via a continuous infusion for the prevention of spinal anesthesia-induced hypotension compared to those who may receive phenylephrine boluses for treatment of spinal anesthesia-induced hypotension. |
Other
| Measure | Time frame |
|---|---|
| Total Vessel Density (TVD) | Immediately prior to, and within 10 minutes of induction of spinal anesthesia |
| Perfused Vessel Density (PVD) | Immediately prior to, and within 10 minutes of induction of spinal anesthesia |
| Proportion of perfused vessels (PPV) | Immediately prior to, and within 10 minutes of induction of spinal anesthesia |
Countries
Canada
Outcome results
None listed