Spinal anesthesia-induced hypotension is a common and clinically significant complication in elderly patients undergoing oncologic surgery. Early identification of patients at risk for hemodynamic instability remains a major challenge in perioperative management. Skin conductance reflects sympathetic nervous system activity and may provide a noninvasive indicator of autonomic responses. This prospective observational study aims to evaluate whether skin conductance measurements can predict the development of hypotension following spinal anesthesia in geriatric oncology patients undergoing urologic surgery. The findings may contribute to improved perioperative monitoring and early risk stratification in this vulnerable patient population.

Spinal anesthesia is widely used in urologic oncology surgery due to its favorable analgesic profile and reduced systemic anesthetic exposure. However, spinal anesthesia frequently leads to significant hemodynamic changes, particularly hypotension, which is more pronounced in elderly patients because of age-related alterations in autonomic regulation, reduced cardiovascular reserve, and increased comorbidity burden. Spinal anesthesia-induced hypotension may result in inadequate tissue perfusion and increased perioperative morbidity, making early identification of patients at risk an important aspect of perioperative management.

Skin conductance is a noninvasive physiological parameter reflecting sympathetic nervous system activity and sudomotor responses. Changes in skin conductance have been associated with variations in autonomic nervous system activity and may provide an indirect indicator of hemodynamic responses. Continuous monitoring of skin conductance may therefore offer a potential method for identifying patients who are more likely to develop hypotension after spinal anesthesia.

The aim of this prospective observational study is to investigate the relationship between skin conductance measurements and the development of hypotension following spinal anesthesia in geriatric oncology patients undergoing urologic surgery. Hemodynamic parameters including blood pressure and heart rate will be monitored perioperatively, and their association with skin conductance measurements will be evaluated. The results of this study may contribute to improving perioperative monitoring strategies and risk prediction in elderly oncology patients undergoing spinal anesthesia.

Inclusion Criteria:

• Patients aged 65 years and older
• Patients scheduled for elective urologic oncology surgery under spinal anesthesia
• American Society of Anesthesiologists (ASA) physical status I-III
• Patients who provide written informed consent to participate in the study

Exclusion Criteria:

• Refusal to participate or inability to provide informed consent
• Contraindication to spinal anesthesia (e.g., infection at puncture site, coagulopathy)
• Severe cardiac conduction abnormalities or presence of a cardiac pacemaker
• Severe autonomic dysfunction or known neuropathy affecting autonomic responses
• Use of medications that significantly affect autonomic nervous system activity
• Baseline hypotension or hemodynamic instability before spinal anesthesia
• Inability to obtain reliable skin conductance measurements (e.g., severe skin lesions at electrode placement site)

The study population will consist of geriatric patients aged 65 years and older who are scheduled to undergo elective urologic oncology surgery under spinal anesthesia at a tertiary oncology training and research hospital. Eligible patients meeting the inclusion criteria will be prospectively enrolled. Perioperative skin conductance and hemodynamic parameters will be monitored to evaluate the association between sympathetic nervous system activity and the development of spinal anesthesia-induced hypotension.

Individual participant data collected during this study will not be made publicly available. The dataset contains sensitive clinical information, and data sharing is restricted to protect participant confidentiality in accordance with institutional policies and ethical regulations. However, de-identified data may be made available from the corresponding investigator upon reasonable request and with appropriate ethical approval.