The relationship between serum cortisol levels and ventilatory weaning in patients treated with mechanical ventilation

1THE RELATIONSHIP BETWEEN SERUM CORTISOL LEVELS ANDVENTILATORY WEANING IN PATIENTS TREATED WITH MECHANICALVENTILATIONDR. EL F REYHAN HANGAZ UNIVERSITYMEDICAL FACULTYPULMONARY MED C NE DEPARTMENTDECEMBER 2006ABSTRACTThe relationship between serum cortisol levels and starting time of weaning,duration of weaning period and mechanical ventilation, reintubation and mortality isnot known exactly. In case of adrenal insufficiency these factors are affectednegatively. In this study, we examined the relationship between serum cortisol levelsin three different time period (beginning, weaning and the last serum cortisol levels)and starting time of weaning, the duration of weaning period and mechanicalventilation, reintubation and mortality.For this purpose fourty six patients (21 women and 25 men) were enrolledwhose median age was 73 (11). Beginning, weaning and the last serum cortisollevels of these patients were analyzed according to 5 groups defined according to thestarting time of weaning, duration of weaning period and mechanical ventilation,reintubation and mortality. Mann-Whitney U test, Pearson and Spearman correlationtests, Chi square test, ROC curve analysis and repeated measures test were usedfor the statistical analysis.2The median value of the beginning serum cortisol levels was 22.2 (4.5) µg/dl.There was a moderate degree of correlation between the beginning serum cortisollevels and the starting time of weaning, duration of weaning period and mechanicalventilation, length of intensive care unit stay and APACHE II scores.The beginning and the weaning serum cortisol levels were higher in patientswith shorter weaning and ventilation period, and the patients in whom the weaningstarted earlier and reintubation not required and the patients that were discharged.Weaning and the last serum cortisol levels predicted the mortality and thereintubation risks better than the beginning serum cortisol levels.Early identification of adrenal insufficiency in critically ill patients can improvethe chances of shorter period of weaning and mechanical ventilation and shorterlength of stay in the intensive care unit and hospital. A comparative, randomizedstudy design to confirm these results is needed.Key words: mechanical ventilation, serum cortisol levels, adrenal insufficiency,intensive care unit (ICU)