The goal of this observational study is to determine the correlation between cerebral oxygenation values measured by near-infrared spectroscopy (NIRS) and other routine monitoring parameters in patients placed in the semi-sitting position.
The primary questions investigated are :
Do NIRS values correlate with heart rate, invasive mean arterial pressure, and end-tidal carbon dioxide?
Do NIRS values reflect changes observed in arterial blood gas analysis?
Are cerebral perfusion-related parameters associated with patients' comorbidities such as diabetes, obesity, and hypertension?
Researchers will compare routine noninvasive monitoring (heart rate, blood pressure, peripheral oxygen saturation) with invasive arterial monitoring and NIRS to assess whether NIRS provides additional information for evaluating cerebral perfusion.
Participants will be monitored for:
Heart rate
Invasive mean arterial pressure
End-tidal carbon dioxide
Arterial blood gas changes
Cerebral oxygenation with NIRS
Patients' comorbidities (e.g., diabetes, obesity, hypertension) will also be recorded, and their association with perfusion-related parameters will be analyzed.
Patients scheduled for orthopedic surgery in the semi-sitting position
ASA physical status I-III
Voluntary participation with informed consent
Patients younger than 18 years
Patients who do not provide consent
History of cerebral ischemia
History of head trauma
Adult patients (18 years and older, ASA I-III) undergoing orthopedic surgery in the semi-sitting position, monitored for cerebral oxygenation (NIRS), invasive arterial pressure, and routine intraoperative parameters.
Cohort
Prospective
Near-Infrared Spectroscopy (NIRS) Monitoring
Diagnostic testCerebral oxygenation will be monitored using NIRS in addition to standard intraoperative monitoring (heart rate, invasive arterial pressure, end-tidal CO₂, and blood gas analysis).
Correlation Between Cerebral Oxygenation (rSO₂) Measured by NIRS and Systemic Oxygenation
The correlation between intraoperative cerebral oxygenation (regional cerebral oxygen saturation, rSO₂) (%)-measured non-invasively using near-infrared spectroscopy (NIRS) -and simultaneous systemic oxygenation assessed using arterial blood gas analysis, including: Arterial pH, PaO₂ (mmHg) and PaCO₂ (mmHg)
Correlation Between Cerebral Oxygenation (rSO₂) Measured by NIRS and Hemodynamic Parameters (Heart Rate and Blood Pressure)
The correlation between intraoperative cerebral oxygenation (regional cerebral oxygen saturation, rSO₂) (%)-measured non-invasively using near-infrared spectroscopy (NIRS) -and systemic hemodynamic parameters. Systemic hemodynamic parameters will include: 1. Heart rate (beats per minute), monitored continuously via electrocardiography (ECG) 2. Noninvasive mean arterial pressure (mmHg), measured using an automated oscillometric device 3. Invasive mean arterial pressure (mmHg), obtained via an arterial catheter
Association of Preoperatively Documented Hypertension with Intraoperative Low Cerebral Oxygenation (rSO₂) Measured by Near-Infrared Spectroscopy
The associations between preoperatively diagnosed hypertension with the occurrence of intraoperative reductions in regional cerebral oxygen saturation (rSO₂), defined as values falling below the normal range (60-75%).
Association of Preoperatively Documented Diabetes Mellitus with Intraoperative Low Cerebral Oxygenation (rSO₂) Measured by Near-Infrared Spectroscopy
The associations between preoperatively diagnosed diabetes mellitus, and the occurrence of intraoperative reductions in regional cerebral oxygen saturation (rSO₂), defined as values falling below the normal range (60-75%).
Association of Preoperatively Documented Obesity with Intraoperative Low Cerebral Oxygenation (rSO₂) Measured by Near-Infrared Spectroscopy
The associations between preoperative obesity-defined as a body mass index (BMI) greater than 30 kg/m²-and the occurrence of intraoperative reductions in regional cerebral oxygen saturation (rSO₂), defined as values falling below the normal range (60-75%).
Click on the lead sponsor to view all of their trials.
