Maternal Microcirculation & SDF Imaging

Maternal Microcirculation & SDF Imaging: A Novel Assessment of the Microcirculation During Cesarean Delivery With Spinal Anesthesia and the Impact of Phenylephrine Prophylaxis to Prevent Spinal Anesthesia-induced Hypotension.

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.

Study Overview

• Status: Completed
• Conditions: Pregnancy
• Intervention / Treatment: Device: Initial MicroScan® (Microvision Medical) SDF Measurement; Drug: Spinal Anesthesia- Bupivacaine; Device: Comparative MicroScan® (Microvision Medical) SDF Measurement; Drug: Bolus Phenylephrine/Ephedrine Treatment; Drug: Phenylephrine Infusion

• Study Type: Interventional
• Enrollment (Actual): 32
• Phase: Phase 4

Contacts and Locations

Study Locations

• Canada
  • Nova Scotia
    • Halifax, Nova Scotia, Canada, B3K 6R8
      • IWK Health Centre

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 45 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: Female

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Bolus Phenylephrine/Ephedrine Treatment'; Initial MicroScan® (Microvision Medical) SDF measurement are recorded in the obstetric preoperative area within two hours prior to administration of spinal anesthesia. In the operating room participants will receive a standard spinal anesthetic (hyperbaric bupivacaine, fentanyl and preservative free morphine) followed by a second comparative MicroScan® (Microvision Medical) SDF measurement within 10 minutes of initiation of spinal anesthetic. Participants who experience hypotension will receive bolus phenylephrine and/or ephedrine treatment as needed.	Device: Initial MicroScan® (Microvision Medical) SDF Measurement; Initial SDF measurements are recorded in the obstetric preoperative area within two hours prior to administration of spinal anesthesia.; Drug: Spinal 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.; Device: Comparative MicroScan® (Microvision Medical) SDF Measurement; A second comparative SDF measurement be recorded within 10 minutes after induction of spinal anesthesia.; Drug: Bolus 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.
Experimental: Phenylephrine Infusion Group; Initial MicroScan® (Microvision Medical) SDF measurement are recorded in the obstetric preoperative area within two hours prior to administration of spinal anesthesia. In the operating room participants will receive a standard spinal anesthetic (hyperbaric bupivacaine, fentanyl and preservative free morphine) followed by a second comparative MicroScan® (Microvision Medical) SDF measurement within 10 minutes of initiation of spinal anesthetic. Participants will have an infusion of phenylephrine started immediately following the induction of spinal anesthesia for prevention of hypotension.	Device: Initial MicroScan® (Microvision Medical) SDF Measurement; Initial SDF measurements are recorded in the obstetric preoperative area within two hours prior to administration of spinal anesthesia.; Drug: Spinal 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.; Device: Comparative MicroScan® (Microvision Medical) SDF Measurement; A second comparative SDF measurement be recorded within 10 minutes after induction of spinal anesthesia.; Drug: Phenylephrine Infusion; Participants will have an infusion of phenylephrine started immediately following the induction of spinal anesthesia for prevention of hypotension.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Microvascular Flow Index (MFI)	The change in MFI of participants; measured immediately prior to, and within 10 minutes following the induction of spinal anesthesia	Immediately prior to, and within 10 minutes of induction of spinal anesthesia

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Microvascular Flow Index (MFI)	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.	Immediately prior to, and within 10 minutes of induction of spinal anesthesia

Other Outcome Measures

Outcome 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

Collaborators and Investigators

• Sponsor: IWK Health Centre
• Investigators: Principal Investigator: Ronald B George, MD FRCPC, IWK Health Centre, Dalhousie University

Publications and helpful links

General Publications

• George RB, DesRoches J, Abdo I, Lehmann C. Maternal microcirculation and sidestream dark field imaging: a prospective assessment of the association between labour pain and analgesia on the microcirculation of pregnant women. Clin Hemorheol Microcirc. 2015;60(4):389-95. doi: 10.3233/CH-141851.
• Abdo I, George RB, Farrag M, Cerny V, Lehmann C. Microcirculation in pregnancy. Physiol Res. 2014;63(4):395-408. doi: 10.33549/physiolres.932511. Epub 2014 Apr 3.
• George RB, Munro A, Abdo I, McKeen DM, Lehmann C. An observational assessment of the sublingual microcirculation of pregnant and non-pregnant women. Int J Obstet Anesth. 2014 Feb;23(1):23-8. doi: 10.1016/j.ijoa.2013.08.013. Epub 2013 Sep 8.
• Lehmann Ch, Abdo I, Kern H, Maddison L, Pavlovic D, Sharawi N, Starkopf J, Hall R, Johnson P, Williams L, Cerny V; MiDAS (Microcirculation Diagnostics and Applied Studies) group. Clinical evaluation of the intestinal microcirculation using sidestream dark field imaging--recommendations of a round table meeting. Clin Hemorheol Microcirc. 2014;57(2):137-46. doi: 10.3233/CH-141810.

Study record dates

Study Major Dates

• Study Start: January 1, 2014
• Primary Completion (Actual): December 1, 2014
• Study Completion (Actual): December 1, 2014

Study Registration Dates

• First Submitted: September 3, 2014
• First Submitted That Met QC Criteria: February 25, 2015
• First Posted (Estimate): March 3, 2015

Study Record Updates

• Last Update Posted (Estimate): March 3, 2015
• Last Update Submitted That Met QC Criteria: February 25, 2015
• Last Verified: February 1, 2015

More Information

Terms related to this study

• Keywords: Microcirculation; Spinal Anesthesia; Phenylephrine; Sidestream Dark Field (SDF) Imaging
• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Adrenergic Agents; Neurotransmitter Agents; Molecular Mechanisms of Pharmacological Action; Central Nervous System Depressants; Autonomic Agents; Peripheral Nervous System Agents; Sensory System Agents; Anesthetics; Protective Agents; Adrenergic alpha-Agonists; Adrenergic Agonists; Cardiotonic Agents; Anesthetics, Local; Respiratory System Agents; Central Nervous System Stimulants; Sympathomimetics; Vasoconstrictor Agents; Mydriatics; Nasal Decongestants; Adrenergic alpha-1 Receptor Agonists; Bupivacaine; Ephedrine; Phenylephrine; Oxymetazoline
• Other Study ID Numbers: IWK1010276