Delirium impact in a chronic ventilatory care unit
© BioMed Central Ltd 2007
Published: 19 June 2007
Delirium has been associated with poor hospital outcomes, including increased morbidity and mortality, prolonged length of stay and functional decline. Recently published clinical practice guidelines from the Society of Critical Care Medicine recommended monitoring for the presence of delirium in all ICU patients, but it has never before been assessed in a group of chronically ventilated patients.
To compare the usual clinical assessment for delirium and the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU), to describe its characteristics in chronically ventilated patients and to evaluate the incidence, associated clinical conditions, length of stay and late mortality.
Patients and methods
A prospective observational study. Delirium was evaluated on a daily basis and followed by a group of previously trained nurses. Twenty-one tracheotomized, mechanically ventilated, awake and cooperative subjects admitted to the ventilatory care unit (VCU) during a period of 12 months were included in the study protocol. The CAM-ICU tool was applied 5 days a week at same time in the afternoon and its data were compared with intensivist and psychiatric evaluations. The results are expressed as the mean ± standard deviation. The chi-square test was used to evaluate differences in proportions; P < 0.05 was considered statistically significant.
Seven females and 14 males were studied. Delirium occurred in 10 (47%) patients during the VCU stay, and the CAM-ICU tool detected 65.38% of it. The mean onset was 14.22 ± 17.27 days and the mean duration was 1.74 ± 0.92 days. There was no difference related to age and APACHE II score between patients with and without delirium: 75.10 vs 67.36 (P = 0.082) and 16.40 vs 16.36 (P = 0.81), respectively. There was a strong association between new infection and delirium diagnosed with the CAM-ICU in spite of a significant difference between the mean titulated C reactive protein level and insulin dose used during the study with delirium patients (D group) and patients with no delirium (ND group): 9.09 ± 5.30 vs 7.10 ± 3.9 and 61.96 ± 77.7 vs 57.69 ± 73.89, respectively. All patients with sensorial deficit presented delirium. The hospital mortality and length of stay did not show any statistically significant difference between both groups.
The incidence of delirium in this study was less than expected. The CAM-ICU demonstrated inferior sensibility to that described in the literature. The presence of delirium was related to early onset of new infection despite normal inflammatory markers. The main limitation of this study was the low number of patients enrolled.