Association Between Preoperative Shock Index and Hypotension After Spinal Anaesthesia for Non- Elective Caesarean Section

March 10, 2022 updated by: Shirish Silwal, B.P. Koirala Institute of Health Sciences

Association Between Preoperative Shock Index and Hypotension After Spinal Anaesthesia for Non-elective Caesarean Section: A Prospective Observational Study

This is a prospective observational study done in parturient planned for non-elective caesarean section. Association between shock index (HR/SBP) and post-spinal hypotension in parturient undergoing non-elective caesarean section will be evaluated in this research.

Study Overview

Status

Completed

Conditions

Detailed Description

Studies have shown that early hypovolemia is insufficient to produce changes in orthostatic heart rate (HR) or systolic blood pressure (SBP). Studies have shown that Shock Index (SI) as a useful indicator for acute hypovolemia. In healthy individuals, acute blood loss less than 450 mL rarely produces abnormal HR or SBP. As, several studies have shown that relationship of baseline heart rate and systolic blood pressure in predicting post spinal hypotension, this study aims to incorporate both the parameters and attempt to develop a single effective predictor for post spinal hypotension in the form of SI.

Methodology After approval from Institutional Review committee of B.P. Koirala Institute of Health Sciences, parturient undergoing non-elective caesarian of ASA PS grade II and urgency category 2 and 3, fulfilling the inclusion criteria will be informed about the study and written consent will be obtained either in labour room or in obstetric emergency ward. During this visit patient's data that includes age, indication of caesarean section, preoperative anxiety (APAIS), gestational age, and duration of fasting, height, weight, BMI and preoperative hemoglobin concentration will be recorded.

The study will be conducted in accordance with the ethical principles of the 1964 Declaration of Helsinki and STROBE (Strengthening the Reporting of Observational studies in Epidemiology) guidelines will be followed. Before patient is shifted to the operating room (OR), ranitidine 50 mg and metoclopramide 10 mg will be administered intravenously via 18 G cannula. The patient will be shifted to operating table and standard monitors 3 lead ECG, pulse oximetry and noninvasive blood pressure will be attached. Baseline vital signs heart rate and noninvasive SBP will be recorded in operation theatre in supine position with 15° left lateral tilt before administering spinal anaesthesia. NIBP will be measured by using cuff size with width of cuff bladder covering at least 40% of arm circumference and length at least 80% and will be measured from EDAN elite V8 monitors. 3 measurements of SBP will be recorded at 1 minute interval and its mean value will be taken as baseline SBP.

Also, shock index (HR/ SBP) will be calculated before administering spinal anaesthesia. At every 1 minute interval until delivery of baby, vitals parameters HR, SBP and MAP will be measured and shock index will be calculated in each time interval. Then, the patient will be placed in sitting position. Under all aseptic precautions, 2.2 ml of 0.5% hyperbaric bupivacaine with 10 µg fentanyl will be administered in sitting position in L4- L5 or L3- L4 interspace after confirmation of free flow of CSF with 25 G Quincke's needle and drug will be injected over 20 secs. Patient will be then immediately put into supine position with a right hip wedge. A 1 L co-loading of Ringer's lactate will be administered rapidly within 10 minutes via an 18 G intravenous line after administering spinal anaesthesia. Phenylepinephrine infusion will be started at 25 microgram/min immediately after the spinal injection. The sensory level of anaesthesia will be checked using loss of cold sensation with the use of alcohol soaked cotton swabs every minute until 20 mins. Surgery will be allowed once the bilateral sensory block height at T6 is achieved. Oxygen at 40% will be administered via nasal cannula at 2-4 L/min until delivery.

Hemodynamic parameters will be recorded at following time intervals: baseline, immediately after spinal anaesthesia, every minute for the first 15 minutes after spinal injection and every 2.5 mins until end of surgery. Hypotension will be treated with phenylephrine 50 µg bolus and rapid infusion of Ringer's lactate 200 ml. If bradycardia (HR< 55/min) is associated with hypotension, IV ephedrine 6 mg will be administered. If these measures fail and bradycardia is still persistent then an IV atropine 0.5 mg will be given. Intraoperative hypertension (defined as SBP greater than 120% of the baseline reading) will be managed by stopping norepinephrine infusion. The infusion will be resumed when blood pressure returns to the upper limit of the target range i.e. 20% above baseline.After delivery of the baby, 3 IU of oxytocin will be administered IV over ≥ 30 sec followed by an infusion of 10 IU/hr (oxytocin 40 IU in 500 ml of Hartmann's solution).

The total amount of intraoperative IV fluids administered and estimated blood loss will be measured. At the conclusion of the surgery, blood loss will be estimated by cumulative measurement of the following: the volume of blood in the suction canister (and subtracting the estimated amniotic fluid from the suction chamber); visual examination of the surgical sponges.

Intraoperative use of other uterotonic agent or blood transfusion will be recorded. The attending pediatrician will assess neonatal Apgar scores at 1 and 5 minutes after delivery.

Patients will be asked to report the occurrence of intraoperative nausea Incidence of intraoperative pruritus, shivering, and dizziness will also be recorded.

The primary outcome measures will be incidence of post spinal hypotension defined as SBP < 80% of baseline reading or SBP < 100 mmHg after administering of spinal anaesthesia until delivery of baby. The secondary outcome measures will be post-delivery hypotension is defined as SBP < 80% of baseline reading or SBP < 100 mmHg observed from starting oxytocin until end of surgery.

Data collection Baseline data (gestational age, preoperative hemoglobin, preoperative anxiety, uterine incision to delivery time, hemodynamic parameters) and outcome parameters will be collected in the paper case record form and entered in windows Microsoft excel spreadsheet and will use STATA version 15.0 for analysis.

Study Type

Observational

Enrollment (Actual)

337

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Nepal
    • Province 1
      • Dharān Bāzār, Province 1, Nepal, 56700
        • Shirish Silwal

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 40 years (Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

Female

Sampling Method

Non-Probability Sample

Study Population

Patients at term undergoing emergency caesarean delivery and falling under category 2 (no immediate threat to life of pregnant women and fetus) and category 3 (requiring early delivery) according to NICE (National Institute for Clinical Excellence) guideline classification of urgency of emergency caesarean section and ASA (American society of Anaesthesiologist) PS (Physical status) grade II under spinal anesthesia will be included.

Description

Inclusion Criteria:

  • All parturient at term (gestational weeks ≥ 37)
  • ASA (American society of Anesthesiologist) PS (Physical status) grade II
  • Category 2 and 3 of non-elective caesarean section

Exclusion Criteria:

  • ASA PS Grade >2
  • Pregnancy induced hypertension
  • Gestational hypertension
  • Known fetal abnormalities
  • Contraindications to spinal anesthesia
  • Multiple pregnancy
  • Baseline SBP< 100 mmHg
  • Intrauterine growth restriction (IUGR)
  • Missing height and/ or weight data
  • Stillbirth
  • Height: <150 cm
  • Ante-partum hemorrhage
  • Cardiovascular, cerebrovascular disease, endocrine disease
  • Gestational diabetes
  • Failed spinal anesthesia requiring GA

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Incidence of post spinal hypotension
Time Frame: time points between administering spinal anesthesia and until delivery of baby before starting oxytocin during surgery
SBP < 80% of baseline reading or SBP < 100 mmHg after administering spinal anesthesia
time points between administering spinal anesthesia and until delivery of baby before starting oxytocin during surgery

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
post-delivery hypotension
Time Frame: During surgery from starting oxytocin after delivery of baby until the end of surgery
< 80% of baseline reading or SBP < 100 mmHg observed
During surgery from starting oxytocin after delivery of baby until the end of surgery

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

B.P. Koirala Institute of Health Sciences

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

January 6, 2021

Primary Completion (Actual)

February 15, 2022

Study Completion (Actual)

February 25, 2022

Study Registration Dates

First Submitted

December 26, 2020

First Submitted That Met QC Criteria

December 30, 2020

First Posted (Actual)

January 5, 2021

Study Record Updates

Last Update Posted (Actual)

March 14, 2022

Last Update Submitted That Met QC Criteria

March 10, 2022

Last Verified

March 1, 2022

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • IRC/ 1872/ 020

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

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

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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