Clinical characteristics and outcomes of mechanically ventilated patients in respiratory intensive care unit according to weaning classification

Abstract

Background: The weaning classification based on the difficulty and duration of the weaning process has been evaluated Purpose:To compare the clinical characteristics and outcomes of patients with three weaning groups (simple, difficult and prolonged weaning) in respiratory intensive care unit (RICU). Design:Prospective observational clinical study Patients and methods: the study included fifty three (53) patients who were admitted to the RICU and required invasive mechanical ventilation for more than 24 hours and they were ready to be weaned. Chest X-ray, arterial blood gases analysis, blood chemistry including renal function tests, liver function tests and serum electrolytes were done. Patients were weaned by using T-piece or PSV < 7cmH2O for two hours. Patients were classified as simple, difficult and prolonged weaning. Baseline characteristics were compared across weaning classifications. Results:The study included 34 cases survived and 19 cases died, according to the weaning outcomes, the patients were divided into 3 groups; 20 cases experienced simple weaning, 20 cases experienced difficult weaning and 13 cases experienced prolonged weaning.Results showed the following factors that affect weaning outcome; pneumonia (P= 0.04), cardiovascular diseases (P= 0.047), low serum Mg++ level (P <0.0001), low serum Ca++ level (P= 0.0001), high serum urea level (P=0.001), ALT (P=0.0001), AST (P=0.0005)RSBI (P<0.0001), minute ventilation (VE) (P= 0.0001), SaO2% (P <0.0001), high respiratory rate (P <0.0001) and duration of MV and ICU stay (P= 0.0001& 0.0002 respectively). Conclusion: Causes and duration of MV can affect weaning outcomes, factors as WBCs count, hemoglobin level, serum urea, albumin, Mg++ and Ca++ levels, respiratory rate, minute ventilation,RSBI, high respiratory rate and Sao2% can affect weaning outcome. Patients with prolonged weaning had longer duration of MV and ICU stay than those with simple and difficult weaning.