The Impact of Multiple Antihypertensive Therapy on Post-Induction Hypotension Burden in Cardiac Surgery Patients

Konya City Hospital160 enrolled

Overview

This study aims to investigate the impact of multiple preoperative antihyperstensive drug use on the burden of post-induction hypotension (PIH) in patients undergoing elective cardiac surgery. The researchers will observe whether the combination of different antihypertensive classes (such as ACE inhibitors, ARBs, beta-blockers, and calcium channel blockers) leads to a higher incidence and severity of blood pressure drops and increased need for vasoactive support during the period between anesthesia induction and surgical incision.

Post-induction hypotension (PIH) is a critical period in cardiac anesthesia that can lead to organ hypoperfusion. This prospective observational study will include patients aged 18-85 with ASA III-IV physical status scheduled for elective cardiac surgery. Preoperatively, patients' chronic antihypertensive medications will be recorded and categorized. Following standard anesthesia induction, hemodynamic parameters will be monitored using invasive arterial blood pressure measurement. PIH burden will be defined as the area under the curve (AUC) for a mean arterial pressure (MAP) lower than 65 mmHg. Additionally, the study will record the total dose of ephedrine or other vasoactive agents required to maintain hemodynamic stability. The primary goal is to determine if multiple antihypertensive therapy is an independent risk factor for increased PIH burden and to compare the effects of different drug combinations on early intraoperative hemodynamics.

Study Type

OBSERVATIONAL

Enrollment

160

Conditions

Hypotension on Induction Cardiac Surgery Antihypertensive Agents

Interventions

Chronic Antihypertensive Medication UseOTHER

Patients' chronic antihypertensive drug use (number of drugs and pharmacological classes) will be recorded. This is an observational study where existing medication regimens (ACE inhibitors, ARBs, Beta-blockers, Calcium Channel Blockers, Diuretics) are documented to analyze their impact on the post-induction hypotension burden (MAP \< 55 mmHg).

Eligibility

Sex: ALLMin age: 40 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Adult patients aged 40 years and older * Undergoing elective cardiac surgery (e.g., isolated CABG, isolated valve surgery, or combined CABG+valve surgery via sternotomy) * Regular use of at least one antihypertensive medication for at least 4 weeks prior to the operation date * Voluntary participation and signed informed consent Exclusion Criteria: * Emergency surgery * Preoperative shock or requirement for high-dose inotropic/vasopressor therapy * End-stage liver or kidney failure * Uncontrolled hypertension * Difficult intubation or prolonged induction process * Ejection fraction less than 35%

Outcomes

Primary Outcomes

Post-induction Hypotension (PIH) Burden

The hypotension burden is defined as the area under the threshold (AUT) for a mean arterial pressure (MAP) \<55 mmHg. It is calculated using the formula: AUT\<55 = ∫(55 - MAP(t))dt for all values where MAP is below 55 mmHg. This measure integrates both the severity and duration of hypotension.

Time frame: From the start of anesthesia induction until 15 minutes post-induction or until central venous catheter placement, whichever occurs first.

Secondary Outcomes

Total Vasopressor Dose

The total amount of vasopressors (e.g., ephedrine, norepinephrine) administered to treat post-induction hypotension.

Time frame: From the start of anesthesia induction until 15 minutes post-induction.

Incidence of Post-induction Hypotension

Percentage of patients experiencing at least one episode of MAP \<55 mmHg.