Perfusion Index as a Predictor of Hypotension Following Sub-arachnoid Block Among Patients Undergoing Lower Segment Caesarean Section

C-section is one of the commonly performed surgical procedures. During this surgical procedure the surgeon cuts into uterine cavity through abdominal wall and takes out the baby. This is done by by making the lower half body of the patient numb by injecting local anesthesia drugs into the space surrounding the spinal cord. This allows the mother to remain awake and immediately bond with the baby once it gets delivered. Also this technique provides effective pain relief both during and after the surgery. However like any other technique or drug it is associated with a number of side effects. The most important being fall in blood pressure. There are numerous ways to treat it. However if one is able to predict fall in blood pressure before administration of anesthetic technique one can easily prevent it. One of the recently discovered novel way to predict fall in blood pressure is Perfusion index which is calculated by Pulse oximeter. It is a device use to check amount of oxygen in blood and heart rate. Perfusion index refers to the total amount of blood present in the limbs of the person. Once we administer drug in the space surrounding the spinal cord the amount of blood in the limbs increases while the amount returning to heart decreases which ultimately results in less amount of blood being pumped out by heart resulting in fall in blood pressure. Therefore theoretically those individuals who have a high baseline Perfusion index will more likely to develop low blood pressure. This study aims to identify the cut off value of perfusion index to predict fall in blood pressure.

Study Overview

• Status: Completed
• Conditions: Hypotension; Spinal Anesthetics Causing Adverse Effects in Therapeutic Use; Hypotension on Induction

Detailed Description

Spinal anesthesia is employed to provide excellent surgical conditions in case of C-Section. It is the anesthetic technique of choice among obstetric patients. However it is associated with sympathectomy which reduces the venous return and ultimately causes hypotension. This hypotension is mainly due to redistribution of blood volume to the peripheral compartment. Perfusion index which is measured by Pulse Oximetery is a ratio of pulsatile to non-pulsatile blood in the peripheral compartment of the body. As spinal anesthesia causes sympathectomy, peripheral blood volume increases. As a result perfusion index value should rise. This will then co-relate with hypotension. In simple terms those individuals who have a high baseline Perfusion index value will more likely to develop hypotension. This study aims to identify the baseline perfusion index value which co-relates with development of hypotension following sub-arachnoid block for C-section.

• Study Type: Observational
• Enrollment (Actual): 90

Contacts and Locations

Study Locations

• Pakistan
  • Federal
    • Islamabad, Federal, Pakistan, 44000
      • Deparment of Anesthesia and Critical Care Medicine, Pakistan Institute of Medical Sciences

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: N/A

• Sampling Method: Non-Probability Sample

Study Population

Pregnant females undergoing elective lower segment caesarean section under spinal anesthesia at Pakistan Institute of Medical sciences will be enrolled in the study.

Description

Inclusion Criteria:

• ASA class II and III
• Elective LSCS under sub-arachnoid block
• Age 18-35 years

Exclusion Criteria:

• Hypertensive disorders of pregnancy
• Autonomic neuropathy
• Fetal distress
• NPO >8h
• Lack of maintenance fluid or oral clear fluid intake during NPO period.
• BMI > 35 kg/m2
• Patients requiring Vasopressor and Ionotropic support.

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort
Low Perfusion index; Pregnant patients having baseline perfusion index less than 3.5 will be enrolled into this group.
High Perfusion index; Pregnant patients having baseline perfusion index ≥ 3.5 will be enrolled into this group.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of hypotension	Number of episodes of hypotension among both groups will be compared.	Intra-operative peroid

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Baseline perfusion index as a predictor of hypotension	Sensitivity and specificity of baseline perfusion index to predict intra-operative hypotension following sub-arachnoid block	Intra operative peroid

Collaborators and Investigators

• Sponsor: Muhammad Haroon Anwar
• Collaborators: Pakistan Institute of Medical Sciences
• Investigators: Principal Investigator: Muhammad Haroon Anwar, MBBS, Department of Anesthesia and Critical Care, Pakistan Institute of Medical Sciences, Islamabad

Publications and helpful links

General Publications

• Lal J, Bansal T, Bhardwaj S, Jain M, Singh AK. A study to evaluate perfusion index as a predictor of hypotension following spinal anesthesia for caesarean section. J Anaesthesiol Clin Pharmacol. 2022 Apr-Jun;38(2):294-299. doi: 10.4103/joacp.JOACP_385_20. Epub 2022 Jun 16.

Study record dates

Study Major Dates

• Study Start (Actual): May 27, 2024
• Primary Completion (Actual): April 30, 2025
• Study Completion (Actual): April 30, 2025

Study Registration Dates

• First Submitted: May 19, 2024
• First Submitted That Met QC Criteria: May 19, 2024
• First Posted (Actual): May 23, 2024

Study Record Updates

• Last Update Posted (Actual): May 28, 2025
• Last Update Submitted That Met QC Criteria: May 27, 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: F-5-2/2024(ERRB)/PIMS

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO