Vagal withdrawal and psychological distress during ventilator weaning and the related outcomes

- Achieving weaning criteria did not guarantee patients' being successfully weaned from mechanical ventilation.
- The vagal withdrawal and psychological distress during ventilator weaning were associated with a failed weaning outcome.
- Maintaining physiological and psychological balances during ventilator weaning is associated with weaning success.

ObjectiveThis study investigated the associations between changes in autonomic nervous system (ANS) function, psychological status during the mechanical ventilation (MV) weaning process, and weaning outcomes.MethodsIn this prospective study, we recruited 67 patients receiving MV for > 24 h at a medical center in northern Taiwan. Patients' ANS function, represented by heart rate variability (HRV), the rapid shallow breathing index (RSBI), anxiety, fear, and dyspnea, was repeatedly measured 10 min before and 30 min after undergoing a weaning trial. Forty-nine patients capable of sustaining a 2-h weaning trial were successfully weaned.ResultsCompared with the failed group, the success group showed significantly smaller decreases in high-frequency HRV (HRV-HF) and smaller increases in RSBI (per 10 breaths/min/L), fear, dyspnea, and anxiety in response to the weaning trial (odds ratio [OR] = 2.19, 0.81, 0.69, 0.66, and 0.77, respectively; p < 0.05). Multivariate analyses revealed that low-frequency HRV before weaning (OR = 2.32; 95% confidence interval [CI] = 1.13-4.78, p = 0.02), changes in HRV-HF (OR = 3.33; 95% CI = 1.18-9.44, p = 0.02), and psychological fear during the weaning process (OR = 0.50; 95% CI = 0.27-0.92, p = 0.03) were three independent factors associated with 2-h T-piece weaning success.ConclusionsANS responses and psychological distress during weaning were associated with T-piece weaning outcomes and may reflect the need for future studies to utilize these factors to guide weaning processes and examine their impact on outcomes.