Role of lung ultrasound in weaning from mechanical ventilation in postoperative neurosurgical ICU patients

Background: Prolonged postoperative mechanical ventilation after intracranial surgery is associated with significant morbidity and mortality. Many traditional tools could help in prediction of weaning success as blood gas analysis (ABG), chest radiography, ventilator parameters and rapid shallow breathing index (RSBI). These tools have a significantly higher failure rate. The aim of this study was to describe the role of transthoracic lung ultrasound (LUS) as a clinical tool in predicting weaning of postoperative mechanically ventilated patients after intracranial surgery.

Patients and method:130 patients who were scheduled for weaning from mechanical ventilation (MV), were prospectively enrolled in the study, age 20-70 years, of either sex. They were randomly allocated into two groups- group C (n=65) were examined by traditional methods chest X- ray, ABG, ventilator parameters and RSBI, and group US (n=65) were examined by traditional methods plus LUS. Diaphragm thickness (DT) and fraction (DTF), lung aeration and extravascular lung water (EVLW) were assessed by LUS.  A failure of weaning was considered when reintubation was needed within 48 hours.

Results: The success rate in group US (LUS+ traditional methods) was 84.6% compared to 66.2% in group C (traditional methods only). The value of diaphragm thickness and fraction were significantly more in the weaning success group than in failure group. B-lines detected by LUS in success and failure groups were ≤2, 3 respectively with no significant difference.

Conclusion: Lung ultrasound as an added tool could decrease failure rate of weaning in postoperative mechanically ventilated patients after intracranial surgery.