Evaluating the Relationship between the Pleth Variability Index and Hypotension and Assessing the Fluid Response in Geriatric Hip Fracture under Spinal Anaesthesia: An Observational Study

OBJECTIVE: We aimed to test the efficacy of the pre-operative Pleth variability index (PVI) in evaluating hypotension that developed after spinal anaesthesia in patients who were spontaneously breathing, pre-operatively hypovolemic, and were at an advanced age. METHODS: This observational study included 94 patients aged >65 years with hip fracture. Demographic data, pre-operative heart rate, non-invasive arterial pressures, PVI values, and haemogram values were continuously measured following spinal anaesthesia. The measurements with and without hypotension were distinguished and their data were compared. RESULTS: The mean age of the patients was 77.4±8.2 years. In total, 56.4% of the patients developed hypotension after spinal anaesthesia, and hypotension was higher in women (p=0.037). Low pre-operative diastolic arterial pressures values were associated with the development of hypotension (p=0.037). The relationship between PVI and post-spinal hypotension was negative but significant (r=−0.239; p<0.05). Depending on the volume loss, an increase in the PVI (p<0.001) and its subsequent significant decrease after treatment in patients with hypotension (p<0.001) was observed. The correlation between noninvasively measured haemoglobin values and the values obtained from arterial blood gas samples was significant (p<0.001). CONCLUSION: This study showed that post-spinal hypotension may be associated with increased as well as decreased PVI values. However, these values cannot be clinically used for predicting pre-operative hypotension in hypovolemic patients.