Early rise in central venous pressure during a spontaneous breathing trial: A promising test to identify patients at high risk of weaning failure?

Abstract

BackgroundThe spontaneous breathing trial (SBT) assesses the risk of weaning failure by evaluating some physiological responses to the massive venous return increase imposed by discontinuing positive pressure ventilation. This trial can be very demanding for some critically ill patients, inducing excessive physical and cardiovascular stress, including muscle fatigue, heart ischemia and eventually cardiac dysfunction. Extubation failure with emergency reintubation is a serious adverse consequence of a failed weaning process. Some data suggest that as many as 50% of patients that fail weaning do so because of cardiac dysfunction. Unfortunately, monitoring cardiovascular function at the time of the SBT is complex. The aim of our study was to explore if central venous pressure (CVP) changes were related to weaning failure after starting an SBT. We hypothesized that an early rise on CVP could signal a cardiac failure when handling a massive increase on venous return following a discontinuation of positive pressure ventilation. This CVP rise could identify a subset of patients at high risk for extubation failure.MethodsTwo-hundred and four mechanically ventilated patients in whom an SBT was decided were subjected to a monitoring protocol that included blinded assessment of CVP at baseline, and at 2 minutes after starting the trial (CVP-test). Weaning failure was defined as reintubation within 48-hours following extubation. Comparisons between two parametric or non-parametric variables were performed with student T test or Mann Whitney U test, respectively. A logistic multivariate regression was performed to determine the predictive value on extubation failure of usual clinical variables and CVP at 2-min after starting the SBT.ResultsOne-hundred and sixty-five patients were extubated after the SBT, 11 of whom were reintubated within 48h. Absolute CVP values at 2-minutes, and the change from baseline (dCVP) were significantly higher in patients with extubation failure as compared to those successfully weaned. dCVP was an early predictor for reintubation (OR: 1.70 [1.31,2.19], p<0.001).ConclusionsAn early rise in CVP after starting an SBT was associated with an increased risk of extubation failure. This might represent a warning signal not captured by usual SBT monitoring and could have relevant clinical implications.

Pooled analysis of central venous pressure and brain natriuretic peptide levels in patients with extubation failure

“…This resut is consistent with Dubo' finding which an early rised CVP levels after extubation increases the risk of extubation failure. 20 However, this association was not before extubation. Since cardiovascular dysfunction may be difficult to detect in patients with positive pressure ventilation 29 , it is difficult to detect cardiac dysfunction before extubation by CVP.…”

Effect of spontaneous breathing trial on extubation in patients with acute exacerbation of chronic obstructive pulmonary disease under mechanical ventilation

“…Noninvasive monitoring of some related indicators may also be used to predict risks introduced by extubation. For example, Dubo et al reported that early CVP (central venous pressure) after SBT initiation may indicate elevated risk of extubation failure [ 20 ]. Keyal et al suggested that patients with invasive mechanical ventilation who successfully completed SBT should be guided by arterial blood gas monitoring to improve extubation success [ 21 ].…”

Re-Intubation Among Critical Care Patients: A Scoping Review

“…A study from Korea described that critical care patients who undergo SBT on low level of pressure support ventilation (ranging from +5 to +10 cmH2O, Positive end expiratory pressure (PEEP) 4 -5 cmH2O) has a successful extubation rate compared to those patients who were not followed the said process (12). Another study found that the patients were eligible for SBT will be ventilated with 5 cmH2O of PEEP and pressure support before starting the SBT and the SBT was performed on "T-piece" that connected to the oxygen source for 1-or 2-hours duration will be decided by their attending physicians (13). After that, those patients were extubated once they were successfully undergone the SBT period (13).…”

“…Another study found that the patients were eligible for SBT will be ventilated with 5 cmH2O of PEEP and pressure support before starting the SBT and the SBT was performed on "T-piece" that connected to the oxygen source for 1-or 2-hours duration will be decided by their attending physicians (13). After that, those patients were extubated once they were successfully undergone the SBT period (13).…”

“…Weak patients have a higher risk of reintubation after spontaneous breathing trial (SBT) (10). Respiratory muscle exhaustion is an important criteria for diagnosing post-extubation respiratory failure because SBT can be demanding especially for critically ill patients (13). In addition, inability to manage secretions are also important risk factors for reintubation (10).…”