BACKGROUND:
Re-intubation of the trachea is one of the complications of the patients encounter with critical illness in the intensive care unit. The incidence of this complication has reported between 2% and 25%. Many risk factors contribute with this phenomenon; such as female sex, aging, narcotic and sedative drugs, etc. Re-intubation increases the duration of hospitalization, as well as pulmonary complications and mortality rate. The aim of this study was to evaluate the risk factors of re-intubation in the intensive care units (ICU) .

METHODS:
This study was a retrospective cross- sectional study and was conducted in 2004 among the data documented 210 medical records. These records were obtained from three ICUs of AL-Zahra medical Center. Incomplete medical records were. All data was extracted and filled in specially-designed questionnaires. Obtained data was analyzed with SPSS software by using Chi-square and t-tests.

FINDINGS:
From the 210 medical records studied, 15 patients (7.1%) were re-intubated. There was a positive correlation between re-intubation and hemoglobin when it was lees than 12 gr/dL or more than 15 gr/dL.

CONCLUSION:
Aging (age>65 years), hyponatermia (Na