Prediction of extubation failure in Intensive Care Unit: systematic review of parameters investigated.

IntroductionExtubation failure (EF) refers to the inability to maintain spontaneous breathing after removal of endotracheal tube. The aim of this review is to identify the best parameter to predict EF in adult intensive care patients.Evidence acquisitionWe searched for publications in PubMed (2000-2016). Studies of patients intubated and mechanically ventilated for more than 24 hours were included and divided in groups basing on the extubation method. 2x2 tables were performed to evaluate the sensitivity, specificity and the predictive values only for those parameters investigated in more than three studies. Studies were divided in groups, basing on time required to define EF (<24 hours, <72 or >72 hours), and EF percentage was calculated for each group.Evidence synthesisOn 443 potentially studies, 26 were included. Rapid Shallow Breathing Index (RSBI) and cough strength parameters were found in more than three studies. RSBI or cough strength parameter showed a sensitivity of 20-88.8% or 55.5-85.2%, a specificity of 68.5-94.8% or 24-49%, a positive predictive value (PPV) of 39.5-66.6% or 24-49% and a negative predictive value of 98-82% or 89.5-96.4%, respectively. EF rate was 12.5%, 15.3% and 22% in patients evaluated within 24 hours, 72 hours and over 72 hours, respectively.ConclusionsThis review shows that all parameters used to predict EF have a low PPV. Therefore, the limitation of use of such predictive tests may prolong unnecessarily the intubation and increase the unfavorable outcome. A prospective study involving all variables could be useful to predict the EF in ICU.