Background:No previous study exists to evaluate serum phosphorus (Ph) level as a predictor of the need to mechanical ventilation (MV). This study was designed to determine the predictive ability of admission serum Ph level on MV in patients admitted in Intensive Care Unit (ICU).Materials and Methods:This prospective study was conducted on 100 patients (>16 years old), admitted to our ICU over 1-year. Patients were classified into two groups according to the days of the need to MV. Group A: Patients who required equal or <5 days MV, and Group B: Patients who required more than 5 days of MV. We measured total serum Ph concentrations at the times of ICU admission, connecting to the ventilator and weaning from the ventilator.Results:There were significant differences between serum Ph concentration on admission to ICU (Group A: 3.39 ± 0.39 mg/dl, Group B: 2.89 ± 0.31 mg/dl, P < 0.001), at the time of connecting to ventilator (Group A: 2.49 ± 0.38 mg/dl, Group B: 2.25 ± 0.26 mg/dl, P = 0.004) and weaning from ventilator (Group A: 3.42 ± 0.33 mg/dl, Group B: 2.98 ± 0.34 mg/dl, P < 0.001) between two groups. Duration of ICU stay in Group A was 6.08 ± 1.48 days and in Group B was 15.35 ± 6.45, this difference was significant (P < 0.001). We found the best cut-off point of 3.07 for serum Ph concentration to predict the longer duration of MV.Conclusion:According to the results of our study, hypophosphatemia may increase the need to MV. Therefore, monitoring serum Ph level is a good prognostic factor to predict the need to ventilation.

Background:No previous study has been done to evaluate the admission serum potassium level as a predictor of morbidity or need for mechanical ventilation. The aim of this study is to determine the predictive ability of serum potassium on admission, in critically ill trauma patients, and to evaluate the relation of the potassium level to organ failure, length of stay, ventilator need, and duration of mechanical ventilation.Materials and Methods:A prospective, observational study was done on 100 patients >16 years old, admitted to the Medical-Surgical Intensive Care Units (ICU), for over one year. Patients were classified into Group A: Patients who required equal or less than five days of mechanical ventilation and Group B: Patients who required more than five days of mechanical ventilation. The total serum potassium concentrations were measured and the Sequential Organ Failure Assessment (SOFA) score was recorded at the time of admission to the ICU, when connected to the ventilator, and then at the time of weaning from the ventilator.Results:There was no significant difference between the Serum K concentrations between the two groups, on admission. However, there were significant difference between the Serum K concentrations at times of receiving and weaning from mechanical ventilation (MV) between the two groups. We found the best cut-off point of 3.45 for serum potassium concentration, to predict the need for longer duration of MV.Conclusion:Development of hypokalemia during an ICU stay is associated with the need for mechanical ventilation. Monitoring of the serum potassium levels may be a good prognostic factor for the requirement of mechanical ventilation.