Preoperative Neutrophil-to-Albumin Ratio and Post-Induction Hemodynamic Vulnerability in Major Oncologic Surgery

Overview

This prospective observational study aims to evaluate whether the preoperative neutrophil percentage-to-albumin ratio (NPAR) is associated with post-induction hemodynamic vulnerability in adult patients undergoing elective major oncologic surgery under general anesthesia. NPAR will be calculated from routine preoperative laboratory results by dividing the neutrophil percentage by the serum albumin level. No additional laboratory tests, medications, invasive procedures, or changes in anesthesia management will be performed for the purposes of the study. Demographic characteristics, preoperative laboratory values, anesthetic data, and hemodynamic measurements will be recorded prospectively. Hemodynamic status will be evaluated during the period between induction of general anesthesia and surgical incision, with a maximum observation period of 20 minutes. Vasopressor use and administered doses will also be recorded. The study will assess the ability of preoperative NPAR to identify patients who may be more susceptible to early hemodynamic instability following induction of general anesthesia.

This is a prospective, observational, non-interventional study involving adult patients undergoing elective major oncologic surgery under general anesthesia. The study is designed to evaluate the relationship between the preoperative neutrophil percentage-to-albumin ratio (NPAR) and post-induction hemodynamic vulnerability. A total of 220 patients are planned to be enrolled using consecutive sampling. Eligible participants will be adults aged 18 years or older who are scheduled for elective major oncologic surgery under general anesthesia, have available preoperative complete blood count and serum albumin measurements, and undergo standard hemodynamic monitoring. NPAR will be calculated by dividing the preoperative neutrophil percentage by the serum albumin concentration in g/dL. Demographic characteristics, ASA physical status, comorbidities, preoperative laboratory values, baseline hemodynamic measurements, induction-related data, intraoperative fluid administration, and vasopressor use and doses will be recorded prospectively. Hemodynamic measurements will be evaluated from induction of general anesthesia until surgical incision, with a maximum observation period of 20 minutes. Participants will be classified according to the presence or absence of post-induction hemodynamic vulnerability. The study will not alter routine anesthetic or surgical management. No additional medication, laboratory test, invasive procedure, or treatment modification will be performed for research purposes. Anesthetic agents, fluid therapy, and vasopressor administration will be determined by the responsible anesthesia team according to routine clinical practice. The predictive performance of NPAR will be evaluated using receiver operating characteristic curve analysis and the area under the curve. Multivariable logistic regression analysis will be used to examine the association between NPAR and post-induction hemodynamic vulnerability while accounting for relevant clinical variables.