Epidemiology of patients admitted to a chronic ventilatory care unit

Introduction

The evolution of intensive care and its results related to the survival of very critically ill patients produce a group of survivors characterized by complex co-morbidities and prolonged dependence on mechanical ventilation (more than 21 days). These survivors require specialized intensive care support for improved results and better resource allocation.

Objective

To describe the epidemiologic profile of patients admitted to a tertiary care hospital's chronic ventilatory care unit.

Materials and methods

In this retrospective study we evaluated each patient's admission form during the period between January 2006 and February 2007 in a seven-bed chronic ventilatory care unit. The collected data consist of: sex, age, APACHE II score, diagnosis, frequency and type of infection, antibiotic utilization, frequency of hemodialysis, ventilatory parameters, length of stay (LOS), frequency of transference to the ICU and mortality. Results are presented as the mean ± SD and percentage.

Results

Sixty-eight patients were enrolled in the study. There were 35 females and 33 males. The mean age and APACHE II score were 74.99 ± 13.97 years and 14.46 ± 5.16, respectively. The main diagnosis was chronic obstructive pulmonary disease (COPD) (42.64%). Pneumonia associated with mechanical ventilation (PAV) was the main source of infection (38.2%), followed by urinary tract infection (2.9%) and bloodstream infection (2.9%). A total of 57.4% of patients were using intravenous antibiotics; 67.64% of patients were colonized with multidrug-resistant bacteria; and 20.58% of patients were on hemodialysis. Noninvasive mechanical ventilation was used in 7.4% of patients. In total, 86.76% of patients were tracheotomized. The most frequent ventilatory mode used was continuous positive airway pressure + pressure support ventilation in 88.2% of patients. The mean inspiratory pressure and PEEP used were 21 ± 3.41 cmH₂O and 8.41 ± 2.03 cmH₂O, respectively. A total 29.41% of patients needed to be transferred to the ICU. The mean LOS was 27.76 ± 25.39 days. The mortality rate was 16.17%.

Conclusion

COPD on prolonged mechanical ventilation was the most frequent cause of admission. PAV was the most frequent source of infection. More than one-half of patients were using antibiotics. There was a high prevalence of multidrug-resistant bacteria colonizing patients. Hemodialysis was used in one-fifth of patients. The majority of patients were ventilated invasively and by spontaneous mode. Almost one-third of patients had to be transferred to the ICU. There was a high LOS, explained by the chronicity of disease. The mortality was less than expected from the APACHE II score.