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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.

Background: Weaning is an essential part of critically ill patients who are on mechanical ventilation. Weaning was classified into simple, difficult and prolonged. Some patients are easily weaned off and others require a more prolonged duration. Methods: 52 patients admitted to the respiratory intensive care unit (RICU) and requiring mechanical ventilation were successfully weaned and classified into simple (20, 37.7%), difficult (20, 37.7%) and prolonged weaning (13, 24.5%). Factors associated with prolonged weaning and outcomes were determined. Results: A total of 53 intubated patients admitted to the RICU (30 (56.6%) males), aged (59.8±14.3) years were included. The following factors are associated with prolonged weaning: ↓ed serum mg++(P< 0.0001) & CA++(P< 0.0001) , ↑ed BUN level (P= 0.001), ↑ed PaCO2 (P0.04), ↓ed SaO2% (P0.0001),presence of ≥2 co-morbidities (P0.02), prolonged duration of MV (P<0.0001) and long ICU stay (P<0.0001). There was no significant relation between prolonged weaning and Modes of MV (p0.2), also A-a gradient ↓ed in patients with prolonged weaning but not significant (P=0.5). In multivariate analysis, prolonged weaning was independently associated with serum Mg+ (OR 0.03, 95% CI 0.003-0.24, P <0.001), and SaO2% change (the beginning-the end of weaning trial) OR 0.91, 95%CI 0.83-0.99, P < 0.04). Regarding baseline serum Mg++ & tidal volume, the cutoff point for predicting prolonged weaning was (≤1.5 .mmol/l & ≤450 ml) with, sensitivity, specificity, PPV NPV and accuracy (61.5%, 92.5%, 72.7%, 88.1%, 77%, P ˂0.0001 and77%,55%, 36% 88%, 66%, P ˂ 0.02, respectively).The cutoff points of PaCO2 ≥49 mmHg & SaO2% ≤91 at first weaning trial & SaO2% change ≥5 (between the beginning and the end of a weaning trial) were strongly associated with prolonged weaning (P ˂0.02, ˂ 0.0001& ˂0.003, respectively). Prolonged weaning was significantly associated with high mortality rate (P˂ 0.0001). Conclusions: Several factors were associated with prolonged weaning, however, when subjected to multivariate analysis, only serum Mg++& SaO2% change significantly predict prolonged weaning. Prolonged weaning is associated with increased ICU stay and higher rate of tracheostomy. Clinical Implications: Prolonged mechanical ventilation is associated with higher rate of reintubation, tracheostomy rate, longer ICU stay and higher mortality. Identification and correction of factors associated with prolonged weaning may change the outcome and prognosis of these patients. In addition, early intervention such as tracheostomy is likely to benefit these patients