Evaluation of Pleth Variability Index in the Lithotomy Position in Geriatric Patients Undergoing Transurethral Resection of the Prostate.

The Pleth Variability Index (PVI) is a non-invasive parameter used to guide fluid management by reflecting respiratory-induced variations in the plethysmographic waveform. While PVI's reliability in various positions has been studied, data on its behavior in geriatric patients undergoing transurethral resection of the prostate (TUR-P) in the lithotomy position remain limited. This study aimed to evaluate the effect of the lithotomy position on PVI in geriatric versus non-geriatric patients under spinal anesthesia. This prospective observational study included 90 patients undergoing elective TUR-P in the lithotomy position under spinal anesthesia. Patients were divided into geriatric (≥65 years, = 48) and non-geriatric (<65 years, = 42) groups. PVI and Perfusion Index (PI) were recorded at baseline, in the supine position, and in the lithotomy position. Fluid and vasopressor requirements, along with hemodynamic parameters, were also analyzed. PVI values at the 5th minute in the lithotomy position were significantly higher in the geriatric group compared to the non-geriatric group ( = 0.019). No significant differences were observed in PI values or intraoperative hypotension rates between the groups. Neurological comorbidities were more prevalent in the geriatric group ( = 0.025). PVI appears to be a more sensitive indicator of fluid responsiveness in elderly patients under spinal anesthesia in the lithotomy position. Its age-dependent variability suggests clinical utility in guiding fluid management in geriatric populations, while the stable hypotension rates support the effectiveness of PVI-guided goal-directed therapy.