J E Holliday1, C Veremakis. 1. Department of Critical Care Medicine, St. John's Mercy Medical Center, St. Louis, MO, USA.
Abstract
BACKGROUND: Previous studies have shown that relaxation biofeedback reduced time on the ventilator for the difficult-to-wean patients. OBJECTIVE: To test the hypothesis that the underlying mechanism of biofeedback ventilator weaning was the reduction of neural respiratory drive (NRD). DESIGN: Prospective, linear regression analysis. SETTING: Critical care medicine department in tertiary health care hospital. SUBJECTS:Fifteen healthy adult volunteers were randomly assigned to the biofeedback group, and 15 healthy adult volunteers were randomly assigned to a control group. INTERVENTIONS:Relaxation feedback was administered while a single variable, PaCO2, was inputted to the respiratory control system and the output measured. While rebreathing 7% CO2/93% O2, the biofeedback group received a baseline session and a relaxation feedback session and the control group received a baseline session and a no feedback session. MEASUREMENTS AND RESULTS: During relaxation feedback, there was a significant (p < 0.001 to p < 0.05) reduction in the slope of minute ventilation (VI), mean inspiratory flow (VT/TI), occlusion pressure in 0.1 s from onset of inspiration (P100), respiration rate (RR), and diaphragm (DA) EMG compared to baseline. We also found the above breathing parameters decreased significantly for relaxation feedback (p < 0.001-0.05), compared to baseline, at maximum end-tidal CO2 (64 +/- 1.2 mm Hg) (all data are expressed as mean +/- SE). The decrease for VI = -4.65 +/- 1.17 L/min, DA EMG = -0.4 +/- 0.21 microV, P100 = -1.13 +/- 0.56 cm H2O, VT/ TI = -144 +/- 82.91 ml/s, and RR = -3.1 +/- 0.79 breaths/min. No significant changes occurred in these parameters for the control group. CONCLUSIONS: We conclude that the addition of the behavioral input of relaxation feedback results in decreasing the values of respiratory parameters that reflect NRD.
RCT Entities:
BACKGROUND: Previous studies have shown that relaxation biofeedback reduced time on the ventilator for the difficult-to-wean patients. OBJECTIVE: To test the hypothesis that the underlying mechanism of biofeedback ventilator weaning was the reduction of neural respiratory drive (NRD). DESIGN: Prospective, linear regression analysis. SETTING: Critical care medicine department in tertiary health care hospital. SUBJECTS: Fifteen healthy adult volunteers were randomly assigned to the biofeedback group, and 15 healthy adult volunteers were randomly assigned to a control group. INTERVENTIONS: Relaxation feedback was administered while a single variable, PaCO2, was inputted to the respiratory control system and the output measured. While rebreathing 7% CO2/93% O2, the biofeedback group received a baseline session and a relaxation feedback session and the control group received a baseline session and a no feedback session. MEASUREMENTS AND RESULTS: During relaxation feedback, there was a significant (p < 0.001 to p < 0.05) reduction in the slope of minute ventilation (VI), mean inspiratory flow (VT/TI), occlusion pressure in 0.1 s from onset of inspiration (P100), respiration rate (RR), and diaphragm (DA) EMG compared to baseline. We also found the above breathing parameters decreased significantly for relaxation feedback (p < 0.001-0.05), compared to baseline, at maximum end-tidal CO2 (64 +/- 1.2 mm Hg) (all data are expressed as mean +/- SE). The decrease for VI = -4.65 +/- 1.17 L/min, DA EMG = -0.4 +/- 0.21 microV, P100 = -1.13 +/- 0.56 cm H2O, VT/ TI = -144 +/- 82.91 ml/s, and RR = -3.1 +/- 0.79 breaths/min. No significant changes occurred in these parameters for the control group. CONCLUSIONS: We conclude that the addition of the behavioral input of relaxation feedback results in decreasing the values of respiratory parameters that reflect NRD.