New insights into weaning from mechanical ventilation: left ventricular diastolic dysfunction is a key player

Intensive Care Med. 2011 Dec;37(12):1976-85. doi: 10.1007/s00134-011-2368-0. Epub 2011 Oct 6.


Purpose: To investigate the diagnostic performance of Doppler echocardiography (DE) in predicting the outcome of weaning from mechanical ventilation in patients without overt cardiac disease.

Methods: Fifty critical care noncardiac patients who fulfilled predetermined criteria for weaning underwent DE before and at the end of spontaneous breathing trial (pre-SBT/end-SBT, respectively). "Conventional" mitral inflow analysis and "advanced" DE parameters [tissue Doppler imaging (TDI)-derived mitral/tricuspid annular velocities and color M-mode Doppler velocity of propagation (V p)] were used to assess left ventricular (LV) diastolic function/filling pressures. Weaning was considered successful if patients had been extubated after successful SBT and sustained spontaneous breathing for more than 48 h.

Results: Twenty-eight patients (56%) failed weaning: 23 patients failed SBT and 5 required reintubation within 48 h. Weaning failure was associated with the degree of LV diastolic dysfunction at pre-SBT (P = 0.01). Patients who failed weaning presented evidence of increased LV filling pressures at pre-SBT, by demonstrating increased E/E m and E/V p ratios compared with patients with successful outcome (P ≤ 0.004); pre-SBT values of lateral E/E m greater than 7.8 and E/V p greater than 1.51 predicted weaning failure with an area under the curve, sensitivity (%), and specificity (%) of 0.86, 79, and 100, and 0.74, 75, and 73, respectively. Lateral E/E m was the only factor independently associated with weaning failure before SBT; OR (95% CI) 5.62 (1.17-26.96), P = 0.03.

Conclusions: Our findings suggest that LV diastolic dysfunction is significantly associated with weaning outcome in critically ill patients with preserved LV systolic function. An E/E m ratio greater than 7.8 may identify patients at high risk of weaning failure.

Keywords: Doppler echocardiography; Left ventricular diastolic dysfunction; Spontaneous breathing trial; Weaning outcome.

MeSH terms

  • Critical Care
  • Critical Illness
  • Echocardiography, Doppler*
  • Female
  • Hemodynamics / physiology
  • Humans
  • Logistic Models
  • Male
  • Middle Aged
  • Prospective Studies
  • Respiration, Artificial*
  • Respiratory Insufficiency / physiopathology
  • Respiratory Insufficiency / therapy
  • Risk Factors
  • Ventilator Weaning / adverse effects
  • Ventilator Weaning / methods*
  • Ventricular Dysfunction, Left / diagnostic imaging
  • Ventricular Dysfunction, Left / physiopathology*
  • Ventricular Function, Left / physiology