BACKGROUND: Parkinson's disease (PD) is a common neurodegenerative disease affecting the quality of life in the elderly. We speculated that PD patients might have abnormal pharmacodynamics due to the degenerative neural system, and the present study was performed to investigate the pharmacodynamics of remifentanil in PD patients. MATERIALS AND METHODS: Two arms of patients were recruited, including 31 PD patients undergoing pulse generator placement after deep brain stimulator implantation and 31 pair-controlled patients undergoing intracranial surgery without PD (NPD). Patients were anesthetized with target-controlled infusion of propofol and remifentanil. The effective concentration of remifentanil to inhibit responses to intubation and skin incision in 50% and 95% patients (EC50 and EC95) was determined by the up and down method. RESULTS: Demographic data, bispectral index, and hemodynamic values were similar between the PD and the NPD groups. The average remifentanil concentration used in the PD group for tracheal intubation is significantly lower than in the NPD group (P<0.001). The EC50 for inhibiting the response to tracheal intubation were 1.86 ng/mL (95% confidential interval [CI], 1.77-1.96 ng/mL) in the PD group and 3.20 ng/mL (95% CI, 3.13-3.27 ng/mL) in the NPD group. The average remifentanil concentration used in the PD group for skin incision is significantly lower than in the NPD group (P<0.001). EC50 for inhibiting the response to skin incision were 2.17 ng/mL (95% CI, 2.09-2.25 ng/mL) in the PD group and 3.09 ng/mL (95% CI, 3.02-3.17 ng/mL) in the NPD group. CONCLUSIONS: The remifentanil concentrations required for inhibiting responses to tracheal intubation and skin incision are reduced markedly in PD patients undergoing pulse generator placement (NCT01992692).
BACKGROUND:Parkinson's disease (PD) is a common neurodegenerative disease affecting the quality of life in the elderly. We speculated that PDpatients might have abnormal pharmacodynamics due to the degenerative neural system, and the present study was performed to investigate the pharmacodynamics of remifentanil in PDpatients. MATERIALS AND METHODS: Two arms of patients were recruited, including 31 PDpatients undergoing pulse generator placement after deep brain stimulator implantation and 31 pair-controlled patients undergoing intracranial surgery without PD (NPD). Patients were anesthetized with target-controlled infusion of propofol and remifentanil. The effective concentration of remifentanil to inhibit responses to intubation and skin incision in 50% and 95% patients (EC50 and EC95) was determined by the up and down method. RESULTS: Demographic data, bispectral index, and hemodynamic values were similar between the PD and the NPD groups. The average remifentanil concentration used in the PD group for tracheal intubation is significantly lower than in the NPD group (P<0.001). The EC50 for inhibiting the response to tracheal intubation were 1.86 ng/mL (95% confidential interval [CI], 1.77-1.96 ng/mL) in the PD group and 3.20 ng/mL (95% CI, 3.13-3.27 ng/mL) in the NPD group. The average remifentanil concentration used in the PD group for skin incision is significantly lower than in the NPD group (P<0.001). EC50 for inhibiting the response to skin incision were 2.17 ng/mL (95% CI, 2.09-2.25 ng/mL) in the PD group and 3.09 ng/mL (95% CI, 3.02-3.17 ng/mL) in the NPD group. CONCLUSIONS: The remifentanil concentrations required for inhibiting responses to tracheal intubation and skin incision are reduced markedly in PDpatients undergoing pulse generator placement (NCT01992692).