Autonomic tone in medical intensive care patients receiving mechanical ventilation and during a CPAP weaning trial.
Mechanical ventilator support and the resumption of spontaneous ventilation or weaning create significant alterations in alveolar and intrathoracic pressure that influence thoracic blood volume and flow. Compensatory autonomic tone alterations occur to ensure adequate tissue oxygen delivery, but autonomic responses may produce cardiovascular dysfunction with subsequent weaning failure. The authors describe autonomic responses of critically ill patients (n = 43) during a 24-hr period of mechanical ventilatory support and during the 24 hr that included their initial spontaneous breathing trial using continuous positive airway pressure. Nearly two thirds of these patients demonstrated abnormal autonomic function and this dysfunction was more severe in those patients who were unable to sustain spontaneous ventilation (n = 15). With further systematic study, autonomic responses may be useful in the identification of patients who are likely to develop cardiac dysfunction with the resumption of spontaneous breathing.
Frazier
Susan K
SK
University of Kentucky College of Nursing, Lexington, KY 40536-0232, USA. skfraz2@email.uky.edu
Moser
Debra K
DK
Schlanger
Rebecca
R
Widener
Jeanne
J
Pender
Lauren
L
Stone
Kathleen S
KS
D001342:Autonomic Nervous System Diseases / Q000175:diagnosis / Q000209:etiology* / Q000378:metabolism / Q000503:physiopathology*; D015400:Clinical Nursing Research; D045422:Continuous Positive Airway Pressure / Q000009:adverse effects* / Q000379:methods / Q000451:nursing; D003422:Critical Care / Q000379:methods; D005260:Female; D006339:Heart Rate; D006706:Homeostasis; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic; D009730:Nursing Assessment; D009820:Ohio; D010865:Pilot Projects; D011446:Prospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D015300:Ventilator Weaning / Q000009:adverse effects*