Retrospective analysis of related factors for patients with weaning difficulties in medical intensive care unit

Abstract

To explore the related factors of difficult-to-wean patients in medical intensive care unit (MICU). A retrospective analysis was performed for 112 patients placed on mechanical ventilation. There were 63 males and 49 females with a mean age of (58 ± 26) years. Their primary diseases included acute exacerbation of chronic obstructive pulmonary disease (AECOPD) (n = 27), pneumonia (n = 20), asthma (n = 12) and neuromuscular diseases (n = 8). Basic admission profiles, underlying diseases, accompanying diseases and pre-weaning changes in physiological indicators were recorded. They were divided into 2 groups: successfully-weaned group and different-to-wean group. Logistic regression analysis was used to analyze the risk factors correlated with the difficult withdrawal of mechanical ventilation. There were 27 (24.1%) difficult-to-wean patients on mechanical ventilation in MICU. Some underlying diseases had statistical significance in both groups, including AECOPD (χ(2) = 6.238, P = 0.028), idiopathic pulmonary fibrosis (χ(2) = 5.232, P = 0.025) and neuromuscular disease (χ(2) = 14.635, P = 0.007). The ratios of difficult-to-wean patients were 9/27, 2/6 and 6/8 respectively. There was statistical significance of pre-admission and pre-weaning oxygenation index between two groups (t = 2.183, 2.162, P < 0.05). Zubrod score at pre-weaning was also significantly different between two groups (t = 9.037, P < 0.05). Logistic regression indicated that the patients with severe heart failure (OR = 5.781), psychological disorders (OR = 4.654), obstructive sleep apnea (OR = 4.012), AECOPD (OR = 3.617) and neuromuscular diseases (OR = 2.885) were more vulnerable to weaning difficulties. The major risk factors of difficult-to-wean patients in MICU include severe heart failure, psychological diseases, obstructive sleep apnea, neuromuscular disease and AECOPD. And oxygenation and self-care capability may also affect weaning significantly.