The question as to whether an aggressive management of post-operative pleural effusion may improve clinical outcomes after major surgery remains unanswered. The aim of this study was to investigate the effect of ultrasound-guided pleural effusion drainage on oxygenation, respiratory mechanics, and liberation from mechanical ventilation in surgical intensive care unit patients. Oxygenation and respiratory mechanics were measured before and after drainage. Over an 18-month period, a total of 62 patients were analyzed. The mean drainage volume during the first 24 h was 864 ± 493 mL, and there were no procedural complications. Both the mean PaO2/FiO2 ratio and lung compliance improved after drainage. Additionally, 41.9% (n = 26) of patients were ventilator-free within 72 h after drainage. Multivariable logistic regression analysis revealed that non-cardiovascular or thoracic surgery (odds ratio [OR] = 4.968, p = 0.046), a longer time interval from operation to the onset of pleural effusion (OR = 1.165, p = 0.005), and a higher peak airway pressure (OR = 1.303, p = 0.009) were independent adverse predictors for being free from mechanical ventilation within 72 h after drainage. Specifically, patients with a time from surgery to the onset of pleural effusion ≤6 days-but not those with an interval >6 days-showed a significant post-procedural improvement in terms of PaO2/FiO2 ratio, PaCO2, peak airway pressure, and dynamic lung compliance. In summary, ultrasound-guided pleural effusion drainage resulted in significant clinical benefits in mechanically ventilated ICU patients after major surgery-especially in those with early-onset effusion who received thoracic surgery.
Keywords: drainage; lung mechanics; oxygenation; post-operative pleural effusion; ultrasound.