The Effect of HPI to Reduce Intraoperative Hypotension in Caesarean Sections

The Effect Of Using Hypotension Prediction Index To Reduce Intraoperative Hypotension In Caesarean Sections: A Randomised Controlled Trial

During caesarean section, blood pressure variations especially a reduction in blood pressure (or hypotension) can bring harmful effects to mother and baby. This usually occurs after spinal anaesthesia is administered. Usually, the anaesthetist will treat hypotension as it occurs. However, a new medical device is now available to predict hypotension. It is called the Hypotension Prediction Index (HPI). This device allows the prediction of hypotension; hence, treatment can be given before it occurs. It has been widely utilised in major surgeries like abdominal tumour surgery and cardiac surgery worldwide and has shown a substantial reduction in hypotension. This study aims to determine whether the duration and severity of hypotension can be reduced when HPI is used in lower segment caesarean sections. The secondary objective of the study is to determine if the complication rate can be reduced in both mother and baby.

Study Overview

• Status: Recruiting
• Conditions: Pregnancy Related; Cesarean Section Complications; Hypotension; Maternal-Fetal Relations
• Intervention / Treatment: Device: Hypotension prediction index; Device: Non invasive Blood Pressure Monitoring

Detailed Description

Hypotension Prediction Index (HPI) has been shown to reduce IOH significantly in non-cardiac and major abdominal surgeries.The role of HPI beyond reducing IOH has also been a subject of research. Andrzejeska et al. demonstrated that the use of HPI in adolescent idiopathic scoliosis surgery leads to lower reductions in post-surgery haemoglobin levels, shorter duration of hypotension and shorter hospital admissions. Additionally, the intervention group had shorter timeframes from the end of surgery to extubation.

The development of a non-invasive finger blood pressure device compatible with HPI called the Acumen IQ cuff, made it possible to use HPI without inserting an arterial catheter. The arterial pressure waveform generated by a non-invasive finger cuff was reliable and in agreement with the radial artery blood pressure. A retrospective analysis was conducted by Frassanito et al. to determine the performance of HPI using arterial waveform recorded by a non-invasive finger probe to predict hypotension in patients undergoing CS under spinal anaesthesia. They have found that HPI, using this non-invasive probe, was able to predict hypotension with a sensitivity and specificity of 83% and 83% at 3 minutes, 97% and 97% at 2 minutes, and 100% and 100% at 1 minute, before it occurs.

This study aims to determine if the solution to reduce IOH lies in predicting intraoperative hypotension during lower segment ceaserean section (CS). The benefits of HPI may extend beyond reducing the incidence and severity of IOH, to bringing positive outcomes to the foetus. This study will determine whether integrating an early warning system produces benefits significant enough to justify changing our anaesthetic practice.

PROBLEM STATEMENT

Varying methods have been utilised to reduce IOH in CS. A novel software, HPI, was developed to predict hypotension, enabling clinicians to institute guided treatment before maternal hypotension occurs. The investigator need to determine if HPI has benefits in CS, thus leading to better maternal and neonatal outcomes.

RESEARCH QUESTION

Can HPI using the non-invasive continuous arterial pressure waveforms reduce the duration and severity of hypotension in patients undergoing CS under spinal anaesthesia?

OBJECTIVES

Study objective:

To determine if HPI has benefits in CS, thus leading to better maternal and neonatal outcomes compared to oNIBP.

Primary outcome:

The duration and severity of hypotensive events reported as a time-weighted average (TWA) - MAP < 65 mmHg in HPI group (intervention) versus standard oNIBP.

Secondary outcomes:

1. To determine whether the use of HPI leads to better maternal outcomes (incidence of nausea and vomiting, blood loss, length of hospital stay, maternal satisfaction, incidence of surgical site infection)
2. To determine whether the use of HPI leads to better foetal outcomes (Apgar scores, umbilical cord pH, length of hospital stay)
3. To determine the amount of vasopressors and inotropes administered throughout CS if HPI is used versus conventional oNIBP monitoring

RESEARCH HYPOTHESIS

Additional parameters from HPI in the CS under spinal anaesthesia will reduce the duration and severity of intraoperative hypotension and provide better maternal and neonatal outcomes.

• Study Type: Interventional
• Enrollment (Estimated): 100
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Syarifah Noor Nazihah Sayed Masri; Phone Number: 0133452456; Email: syarifahnazihah@yahoo.com.my
• Study Contact Backup: Name: Nadhirah Abdul Halim; Phone Number: +60 16-969 7554; Email: naddyhalim90@gmail.com

Study Locations

• Malaysia
  • Wilayah Persekutuan Kuala Lumpur
    • Cheras, Wilayah Persekutuan Kuala Lumpur, Malaysia, 56000
      • Recruiting
      • Hospital Canselor Tuanku Muhriz
      • Contact: Syarifah Noor Nazihah Sayed Masri; Phone Number: 0133452456; Email: syarifahnazihah@yahoo.com.my

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

Description

Inclusion criteria:

• ≥ 37 weeks of gestation
• Elective CS
• Age between 18 - 40 years old
• Singleton pregnancy
• Planned for spinal anaesthesia

Exclusion criteria:

• American Society of Anesthesiologists (ASA) III and above
• Body mass index (BMI) ≥ 40 kg/m2
• Increased risk of developing peripartum haemorrhage
• History of peripartum haemorrhage
• Placenta previa major, accrete, increta, percreta
• Gravida ≥ 5
• Presence of large uterine fibroids
• Congenital bleeding disorders such as Haemophilia A, Haemophilia B and Von Willebrand disease
• Acquired bleeding disorders such as thrombocytopenia and coagulopathy
• Contraindications to finger cuff orNIBP application, such as finger ischaemia, upper limb neurological deficit, discoloured nail
• Cardiac arrhythmias and aortic regurgitation
• Patient's refusal

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Group 1: HPI Group; There were 2 arm group, in Group 1the Acumen IQ cuff, with HPI and other haemodynamics parameters, is available to the anaesthetist to view and act upon.	Device: Hypotension prediction index; HPI and other haemodynamics parameters, is available to the anaesthetist to view and act upon; Other Names: HPI
Placebo Comparator: Group 2: NIBP Group; the attending anaesthetist will be blinded from the HPI parameters.	Device: Non invasive Blood Pressure Monitoring; Anaesthetist will respond to hemodynamic variables using NIBP; Other Names: NIBP

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Time-weighted average of Mean arterial pressure <65mmHg	Calculated using a formula. TWA-MAP < 65 mmHg = (the depth of hypotension< MAP of 65 mmHg x time spent below a MAP of 65 mmHg (minutes))/(total duration of operation (minutes))	From spinal anaesthesia to completion of surgery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of nausea and vomiting,	Maternal incidence of nausea and vomiting	Perioperative up to 2 days
length of hospital stay	maternal length of hospital stay	Perioperative up to 2 weeks
incidence of surgical site infection	maternal surgical site infection	Perioperative up to 2 weeks
maternal satisfaction	Likert scale from 1 (very unsatisfied) to 5 (very satisfied)	Perioperative up to 2 weeks
Umbilical cord PH	Umbilical cord PH taken after after delivery of baby	Immediately upon delivery of baby
Neonatal length of stay	Neonatal length of stay	Perioperative up to 2 weeks
Apgar score of feotal	Apgar scores of 0-10 ( Apgar score of 7 and more is considered normal)	1 minute and 5 minutes after delivery

Collaborators and Investigators

• Sponsor: National University of Malaysia
• Investigators: Principal Investigator: Azlina Masdar, National University of Malaysia

Publications and helpful links

General Publications

• Sun LY, Wijeysundera DN, Tait GA, Beattie WS. Association of intraoperative hypotension with acute kidney injury after elective noncardiac surgery. Anesthesiology. 2015 Sep;123(3):515-23. doi: 10.1097/ALN.0000000000000765.
• Frassanito L, Sonnino C, Piersanti A, Zanfini BA, Catarci S, Giuri PP, Scorzoni M, Gonnella GL, Antonelli M, Draisci G. Performance of the Hypotension Prediction Index With Noninvasive Arterial Pressure Waveforms in Awake Cesarean Delivery Patients Under Spinal Anesthesia. Anesth Analg. 2022 Mar 1;134(3):633-643. doi: 10.1213/ANE.0000000000005754.
• Murabito P, Astuto M, Sanfilippo F, La Via L, Vasile F, Basile F, Cappellani A, Longhitano L, Distefano A, Li Volti G. Proactive Management of Intraoperative Hypotension Reduces Biomarkers of Organ Injury and Oxidative Stress during Elective Non-Cardiac Surgery: A Pilot Randomized Controlled Trial. J Clin Med. 2022 Jan 13;11(2):392. doi: 10.3390/jcm11020392.
• Andrzejewska A, Miegon J, Zacha S, Skonieczna-Zydecka K, Jarosz K, Zacha W, Biernawska J. The Impact of Intraoperative Haemodynamic Monitoring, Prediction of Hypotension and Goal-Directed Therapy on the Outcomes of Patients Treated with Posterior Fusion Due to Adolescent Idiopathic Scoliosis. J Clin Med. 2023 Jul 9;12(14):4571. doi: 10.3390/jcm12144571.

Study record dates

Study Major Dates

• Study Start (Actual): January 1, 2025
• Primary Completion (Estimated): October 31, 2025
• Study Completion (Estimated): January 31, 2026

Study Registration Dates

• First Submitted: March 9, 2025
• First Submitted That Met QC Criteria: March 21, 2025
• First Posted (Actual): March 25, 2025

Study Record Updates

• Last Update Posted (Actual): May 23, 2025
• Last Update Submitted That Met QC Criteria: May 20, 2025
• Last Verified: May 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Vascular Diseases; Cardiovascular Diseases; Hypotension
• Other Study ID Numbers: JEP-2024-463

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: The data of the study will be available in public data repository
• IPD Sharing Time Frame: After completion of the study and analysis for 5 years
• IPD Sharing Access Criteria: With permission from corresponding author
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF; ANALYTIC_CODE; CSR

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No