Clinical study of Dysfunctional Ventilatory Weaning Response in critically ill patients.

The final sample was 93 patients, from 198 admitted and 117 followed, so exclusions and losses may limit generalisability. The study was done in four adult ICUs in two Brazilian teaching hospitals, one a trauma and emergency reference centre, and the patients were very sick; the 44.09% DVWR incidence was higher than the 5% to 30% range reported in previous studies. Some variables had very few patients in a category, which made odds ratio estimation unstable, including vasopressors, secretion amount, muscle retraction and anxiety. The anxiety score was an adapted reduced scale used in ventilated patients, and some clinical indicators were assessed at the bedside, so subjective measurement error is possible. Several NANDA-I related factors were not evaluated, including sleep pattern alteration, pain, inadequate nutrition, low self-esteem, trust, knowledge, hopelessness, helplessness, fear, motivation, environmental barriers, energy demands, inappropriate weaning pace and social support. Neurological disorders, unplanned extubation, previous extubation failure, tracheostomy and death or transfer before the end of weaning were excluded, so findings may not apply to those groups. Because this was an observational cohort, associations such as post-extubation noninvasive ventilation, vasopressors and antibiotics may reflect sicker patients rather than cause DVWR.

Do not read the 44.09% incidence or the risk factor associations as proof that these factors caused failed weaning. This was an observational cohort, and treatments such as noninvasive ventilation after extubation, vasopressors and more antibiotics may mark sicker patients rather than cause failure.