Application of heart-rate variability in patients undergoing weaning from mechanical ventilation
1 Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
2 Department of Traumatology, National Taiwan University Hospital, No. 7, Chung-Shan South Road, Taipei 100, Taiwan
3 Graduate Institute of Clinical Medicine, National Taiwan University, Taipei, Taiwan
4 School of Medicine, College of Medicine, Fu-Jen Catholic University, New Taipei, Taiwan
5 Cardiovascular Center, National Taiwan University Hospital Yun-Lin Branch, Yunlin, Taiwan
6 Graduate Institute of Epidemiology and Preventive Medicine, National Taiwan University, Taipei, Taiwan
Critical Care 2014, 18:R21 doi:10.1186/cc13705Published: 23 January 2014
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.
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.
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.
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.