Study objective: To evaluate the sensitivity and specificity of various predictors of hypotension during onset of spinal anesthesia in elderly patients.
Design: Prospective study.
Setting: 32 ASA physical status I, II, and III patients, aged >or=60 years, scheduled for elective lower limb surgery with spinal anesthesia.
Interventions: Patients received spinal anesthesia with 10-17.5 mg of bupivacaine. No prophylactic ephedrine or fluid preloading was used.
Measurements: A 5-minute baseline was recorded and during onset of spinal anesthesia, hemodynamic changes were measured every 10 seconds from the radial artery pressure curve. Data collection ended when patients were ready for surgery, or if ephedrine was given to increase mean arterial pressure.
Main results: 21 patients had hypotension. Baseline blood pressure variability low-frequency band power (BPV LF) >8 mmHg(2) and near-infrared spectroscopy (NIRS) reduction >or=5% had high sensitivity (0.73 and 0.90, respectively) and specificity (0.78 and 0.64, respectively), and were significantly associated with the development of hypotension.
Conclusions: Only NIRS and BPV LF could significantly predict hypotension among the elderly.