CNAP vs IABP in Pregnant Women With Placenta Accreta

Study Overview
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Brief Summary
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The objective of this study is to investigate a technique to monitor blood pressure in women undergoing cesarean delivery with suspected placenta accreta spectrum. To achieve this objective, the investigators plan to conduct a prospective, observational study with the following aims: Specific Aim 1: Compare concordance between the systolic (SBP), diastolic (DBP), and mean arterial blood pressure (MAP) readings from the continuous non-invasive arterial blood pressure (CNAP) and IABP at several discrete points throughout the procedure Specific Aim 2: Determine the feasibility of using CNAP to aid in decision making by examining the parameters of volume responsiveness and arterial elastance at several discrete points throughout the procedure. The investigators hypothesize that the investigators can obtain similar blood pressure monitoring using CNAP as compared to the gold standard IABP in women undergoing cesarean delivery with suspected placenta accreta.

Detailed Description
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Study Overview This is a prospective, observational study. Study Procedures Patients who meet inclusion criteria with no exclusions will be approached to provide written informed consent. Enrolled patients will undergo the standard pre-operative evaluation and preparation for cesarean section with possible hysterectomy including evaluation by nursing, obstetrics and anesthesiology team, placement of 2 large bore IVs, arterial line placement and laboratory tests. The patient will then be transported to the OR. In the OR the CNAP device will be placed on the patient's finger and be given a brief calibration period of 45 seconds. As per usual for this procedure, each patient will undergo combined spinal epidural anesthesia with our standard cesarean induction dose of hyperbaric intrathecal 0.75% bupivacaine 1.5ml, intrathecal fentanyl 25 micrograms and intrathecal morphine 250 micrograms. The patient will be moved to the supine position with left lateral uterine displacement. When a T6 sensory level to pinprick is achieved, surgery will be allowed to proceed. Throughout the surgery, the CNAP and IABP will take continuous reading of blood pressure and hemodynamic variable. Labs and additional fluid or blood may be given to the patient as clinically indicated, as is common for this procedure. Blood work will be obtained from the arterial line used for IABP, as is standard practice when an AIBP is in place. Other than the addition of the CNAP cuff, all other care will be per standard protocol for this procedure. Data Collection In order to assess our primary and secondary outcomes, the investigators will be collecting CNAP and AIBP. Additional baseline characteristics including, but not limited to age, race, gender, BMI and comorbidities will be abstracted from the medical record. REDCap will be utilized for data collection and storage. Primary Outcomes SBP, MAP, DBP reading from the CNAP and AIBP at several discrete points throughout the procedure. Secondary Outcomes Additional comparisons of SBP, MAP, DBP measurements using CNAP to AIBP and NIBP, review of extrapolated data outputs including Stroke Volume, Systemic Vascular Resistance, Cardiac Output and Stroke Volume Variation from CNAP compared pulse pressure index from pulse oximetry and AIBP and their responsiveness to fluid bolus, subgroup analysis of CNAP and AIBP during times significant intravascular volume depletion (blood loss) or systemic vascular resistance change (after spinal anesthesia). Relevant clinical data will also be collected, including; demographic data, total estimated blood lose, total quantitative blood loss, length of hospital stay, routine lab results including; Hematocrit, Fibrinogen, coagulation tests, lactic acid, pH, base excess.

Official Title
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Comparison of Continuous Non-Invasive Arterial Blood Pressure to Invasive Arterial Blood Pressure Measurement in Pregnant Women With Placenta Accreta

Conditions
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Hemorrhage, Hemorrhage, Postpartum, Placenta Accreta, Blood Pressure

Intervention / Treatment
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* Device: LiDCO CNAP Monitoring Equipment


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Women aged 18-40 years old with pregnancy complicated by accreta spectrum undergoing elective, scheduled cesarean delivery and possible hysterectomy Exclusion Criteria: Women aged <18 Patients with cardiac arrhythmia Vascular pathologies of the upper limbs (recent vascular surgery, Reynaud's disease, vascular stenosis) Contraindication to neuraxial anesthesia Emergent cases Droplet or airborne precautions (as determined by BIDMC infection control policy)

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 40 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Pregnant women with suspected placenta accreta<br>Pregnant women undergoing cesarean delivery with suspected placenta accreta spectrum. | Device: LiDCO CNAP Monitoring Equipment<br>* A continuous non-invasive arterial blood pressure monitor for rapidly changing hemodynamics.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Comparing concordance between MAP from the CNAP and AIBP | Comparing concordance of systolic blood pressure, mean arterial blood pressure, and diastolic blood pressure readings captured from the continuous non-invasive arterial blood pressure measurements and invasive arterial blood pressure measurements. | MAP will be measured continuously throughout the operative case, with an average case timeframe of 4-6 hours. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Additional Comparisons of SBP and DBP |  | SBP and DBP will be measured continuously throughout the operative case, with an average case timeframe of 4-6 hours. | 
| Stroke Volume | Review of extrapolated data outputs to assess the volume of blood ejected from each ventricle due to the contraction of the heart muscle which compresses these ventricles, measurements in millilitres. | Measured throughout the operative case, with an average case timeframe of 4-6 hours. | 
| Systemic Vascular Resistance | Review of extrapolated data outputs to assess changes in the arterioles. | Measured throughout the operative case, with an average case timeframe of 4-6 hours. | 
| Cardiac Output | Review of extrapolated data outputs to assess heart rate product. | Measured throughout the operative case, with an average case timeframe of 4-6 hours. | 
| Stroke Volume Variation | Review of extrapolated data outputs assessing the change in the amount of blood ejected from the left ventricle into the aorta with each heartbeat | Measured throughout the operative case, with an average case timeframe of 4-6 hours. | 
| Subgroup analysis of CNAP and AIBP | Analysis of continuous non-invasive arterial blood pressure measurements and invasive arterial blood pressure measurements during times significant intravascular volume depletion (blood loss) or systemic vascular resistance change (after spinal anesthesia). This will include the above derived variables (SV, SVR, CO, SVV) and compare them to pulse pressure variation to assess potential value of these measures in the assessment volume depletion and fluid responsiveness. | Measured throughout the operative case, with an average case timeframe of 4-6 hours. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Placenta Accreta, Non-Invasive Arterial Blood Pressure, Invasive Arterial Blood Pressure, Hemorrhage, Hemorrhage, Postpartum