Application of heart-rate variability in patients undergoing weaning from mechanical ventilation.
BACKGROUND
The process of weaning may impose cardiopulmonary stress on ventilated patients. Heart-rate variability (HRV), a noninvasive tool to characterize autonomic function and cardiorespiratory interaction, may be a promising modality to assess patient capability during the weaning process. We aimed to evaluate the association between HRV change and weaning outcomes in critically ill patients.


METHODS
This study included 101 consecutive patients recovering from acute respiratory failure. Frequency-domain analysis, including very low frequency, low frequency, high frequency, and total power of HRV was assessed during a 1-hour spontaneous breathing trial (SBT) through a T-piece and after extubation after successful SBT.


RESULTS
Of 101 patients, 24 (24%) had SBT failure, and HRV analysis in these patients showed a significant decrease in total power (P = 0.003); 77 patients passed SBT and were extubated, but 13 (17%) of them required reintubation within 72 hours. In successfully extubated patients, very low frequency and total power from SBT to postextubation significantly increased (P = 0.003 and P = 0.004, respectively). Instead, patients with extubation failure were unable to increase HRV after extubation.


CONCLUSIONS
HRV responses differ between patients with different weaning outcomes. Measuring HRV change during the weaning process may help clinicians to predict weaning results and, in the end, to improve patient care and outcome.
Chun-Ta
CT
Huang
Yi-Ju
YJ
Tsai
Jou-Wei
JW
Lin
Sheng-Yuan
SY
Ruan
Huey-Dong
HD
Wu
Chong-Jen
CJ
Yu
D000368:Aged; D000369:Aged, 80 and over; D016638:Critical Illness / Q000628:therapy*; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012121:Respiration, Artificial / Q000639:trends*; D015300:Ventilator Weaning / Q000009:adverse effects / Q000639:trends*