Anesthesia, General, Frailty, Hypotension on Induction
Conditions
Keywords
Post-induction hypotension, EASIX, Endothelial Activation and Stress Index, Frailty, Perioperative hemodynamics, Non-cardiac surgery, Clinical Frailty Scale
Brief summary
Post-induction hypotension (PIH) is a common and clinically significant hemodynamic complication following general anesthesia induction. Frail patients are particularly vulnerable due to impaired vascular reactivity and endothelial dysfunction. The Endothelial Activation and Stress Index (EASIX), calculated from routine laboratory parameters (LDH, creatinine, and platelet count), may serve as a preoperative biomarker to identify patients at risk for PIH. This prospective observational cohort study aims to evaluate the association between preoperative EASIX score and the occurrence of post-induction hypotension in frail patients undergoing elective non-cardiac surgery under general anesthesia. A total of 160 patients with a Clinical Frailty Scale (CFS) score of 4 or above will be enrolled. Mean arterial pressure will be measured every 2 minutes for the first 15 minutes after induction. PIH is defined as MAP below 65 mmHg and/or a decrease of 20% or more from baseline.
Detailed description
EASIX is calculated as: LDH (U/L) × Creatinine (mg/dL) / Platelet count (10⁹/L), using routine preoperative laboratory values obtained within 24 hours before surgery. All patients will receive a standardized anesthesia induction protocol: midazolam 0.05 mg/kg, fentanyl 2 mcg/kg, propofol 2 mg/kg, and rocuronium 0.6 mg/kg intravenously, followed by endotracheal intubation after 2 minutes of mask ventilation. Anesthesia maintenance will consist of 2% sevoflurane and remifentanil 0.2 mcg/kg/min infusion. The primary outcome is the occurrence of PIH within the first 15 minutes after induction. Secondary outcomes include the diagnostic performance of EASIX (ROC-AUC analysis) and the interaction between frailty severity and EASIX on PIH development. Multivariable logistic regression will be performed adjusting for age, sex, ASA classification, baseline MAP, antihypertensive medication use, fasting duration, and induction agent doses.
Interventions
OTHEREASIX Score Assessment
Preoperative Endothelial Activation and Stress Index (EASIX) score calculated from routine laboratory parameters obtained within 24 hours before surgery. Formula: LDH (U/L) × Creatinine (mg/dL) / Platelet count (10⁹/L). No additional blood sampling is performed; only existing routine preoperative laboratory values are used.
Sponsors
Konya City Hospital
Study design
Observational model
COHORT
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Age 18 years or older * Scheduled for elective non-cardiac surgery under general anesthesia * Clinical Frailty Scale (CFS) score of 4 or above * Available routine preoperative laboratory values (LDH, creatinine, platelet count) within 24 hours before surgery
Exclusion criteria
* Cardiac surgery * Emergency surgery * Preoperative vasopressor infusion * Severe hematological disease * Missing laboratory data required for EASIX calculation
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Incidence of Post-Induction Hypotension | Within the first 15 minutes after anesthesia induction | Occurrence of MAP below 65 mmHg and/or a decrease of 20% or more from baseline mean arterial pressure, measured every 2 minutes for the first 15 minutes after anesthesia induction, before surgical incision. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Diagnostic Performance of EASIX Score for Post-Induction Hypotension | Preoperative assessment within 24 hours before surgery | Area under the receiver operating characteristic curve (ROC-AUC) of preoperative EASIX score for predicting post-induction hypotension. EASIX is calculated as: LDH (U/L) × Creatinine (mg/dL) / Platelet count (10\^9/L). ROC-AUC ranges from 0.5 (no discrimination) to 1.0 (perfect discrimination); higher values indicate better predictive performance. Optimal cut-off value will be determined by Youden index. |
| Interaction Between Frailty Severity and EASIX on Post-Induction Hypotension | Within the first 15 minutes after anesthesia induction | Effect modification of Clinical Frailty Scale (CFS) score on the association between preoperative EASIX score and post-induction hypotension, evaluated by multivariable logistic regression with interaction term. CFS ranges from 1 (very fit) to 9 (terminally ill); higher scores indicate greater frailty. EASIX is a continuous score with no fixed range; higher values indicate greater endothelial stress. Results will be reported as odds ratios with 95% confidence intervals. |
Countries
Turkey (Türkiye)
Contacts
CONTACTMustafa Aydemir, MD
PRINCIPAL_INVESTIGATORMustafa Aydemir, MD
Konya City Hospital
Outcome results
None listed