What Causes Low Blood Pressure After Anesthesia in Older Adults Having Non-Heart Surgery ?

Summary

The purpose of this study is to identify risk factors contributing to post-induction hypotension in geriatric patients undergoing elective non-cardiac surgery under general anesthesia at Dr. Cipto Mangunkusumo National Central Public Hospital. Post-induction hypotension is defined as a decrease in Mean Arterial Pressure (MAP) of more than 30% from baseline after anesthesia induction up to 20 minutes post-induction. This condition can lead to adverse effects such as myocardial injury, acute kidney injury, stroke, and even death.

This research aims to answer several key questions, including whether the following factors influence the risk of post-induction hypotension:

* Airway management with endotracheal intubation.
* Low albumin levels.
* Presence of comorbidities such as hypertension, cancer/malignancy, diabetes mellitus, chronic heart disease, and chronic kidney failure.
* Dose of propofol during anesthesia induction.
* Dose of fentanyl administered during anesthesia induction.
* Dose of midazolam administered during anesthesia induction.
* Frailty score.

This study is an observational analytical study with a prospective cohort design. Data will be collected from medical records and direct observation of geriatric patients who meet the inclusion and exclusion criteria. Sampling will be done using a consecutive sampling method. The targeted sample size is 333 subjects, accounting for a 10% dropout rate.

Study subjects will meet the inclusion criteria: geriatric patients over 60 years old undergoing elective non-cardiac surgery under general anesthesia with ASA (American Society of Anesthesiologists) classification I-IV. Exclusion criteria include patients receiving a combination of general anesthesia with regional or epidural anesthesia, more than 2 attempts at endotracheal intubation, patients already intubated before the surgical procedure, those receiving vasopressors or inotropics before general anesthesia induction, and intentional hypotension within 20 minutes after intubation.

The data to be recorded include patient characteristics, ASA classification, history of comorbidities, medications consumed, vital signs (before entering the operating room, upon arrival in the operating room, immediately after intubation, and at 5, 10, 15, and 20 minutes after intubation), type of surgery, anesthesia technique, type of anesthetic gas used, total doses of propofol, fentanyl, and midazolam with their administration times, laboratory results, chest X-ray results, presence or absence of endotracheal intubation procedure, administration of vasopressors or inotropics before induction, and patient position during blood pressure measurements. Data analysis will be performed using Graphpad Prism version 10 for MacOS, including descriptive analysis, normality tests, bivariate tests (Chi-square or Fisher's exact test, T-test or Mann-Whitney), and multivariate analysis using Cox regression to identify risk factors and determine relative risk.

Conditions

• Geriatric
• General Anesthesia Induced Hypotension
• Elective Surgery
• Hypotension
• Risk Factor

Interventions

DRUG

Standard General Anesthesia Induction Using Propofol, Fentanyl and Midazolam

This intervention refers to the standard induction of general anesthesia in geriatric patients undergoing elective non-cardiac surgery. Induction typically involves the administration of intravenous anesthetic agents such as propofol and fentanyl, based on institutional protocols and the anesthesiologist's discretion. This study does not modify or introduce any new treatment; it merely observes and records peri-induction parameters to identify factors associated with the occurrence of post-induction hypotension.

DEVICE

Blood Pressure Continous Monitoring, syrnge pump for the anesthesia agent, and vasoconstrictor drug

This intervention involves the standard clinical use of non-invasive continuous blood pressure monitoring during the induction of general anesthesia in geriatric patients undergoing elective non-cardiac surgery. Intravenous anesthetic agents (e.g., propofol, fentanyl) and vasopressors (e.g., ephedrine, norepinephrine) are administered via syringe pumps based on the anesthesiologist's clinical judgment. The study does not introduce any experimental treatment but observes blood pressure changes in real time to identify risk factors for post-induction hypotension. The integration of continuous hemodynamic monitoring distinguishes this observational approach from routine anesthetic induction without such monitoring.

Sponsors & Collaborators

• Indonesia University

  lead OTHER

Study Design

Allocation

NA

Purpose

PREVENTION

Masking

NONE

Model

SINGLE_GROUP

Eligibility

Min Age

60 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2024-09-01

Primary Completion

2025-03-15

Completion

2025-03-15

FDA Drug

Yes

FDA Device

Yes

Countries

• Indonesia

Study Locations