The evolution of diaphragm activity and function determined by ultrasound during spontaneous breathing trials

• Published in: Journal of critical care Vol. 51; pp. 133 - 138
• Main Authors: Rittayamai, Nuttapol, Hemvimon, Sivaporn, Chierakul, Nitipatana
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.06.2019; Elsevier Limited
• Subjects: Age; Aged; Aged, 80 and over; Blood pressure; Coma; Critical care; Diaphragm; Diaphragm (Anatomy); Diaphragm - diagnostic imaging; Diaphragm - physiology; Extubation; Female; Humans; Inhalation - physiology; Inspiratory effort; Male; Middle Aged; Neuromuscular diseases; Patients; Prospective Studies; Respiration; Spontaneous breathing trial; Ultrasonic imaging; Ultrasonography; Ultrasonography - methods; Ventilation; Ventilator Weaning - methods; Ventilators; Weaning; SBT; Weaning; PEEP; FiO2; Spontaneous breathing trial; RSBI; PaO2; SOFA; PTPes; TFditidal; Ultrasonography; Tdi; Diaphragm; DEmax; TFdimax; APACHE; Inspiratory effort; PTPdi
• ISSN: 0883-9441; 1557-8615
• DOI: 10.1016/j.jcrc.2019.02.016

Rapid shallow breathing index (RSBI) is a commonly used index for predicting the outcome of spontaneous breathing trial (SBT). Ultrasound is a non-invasive technique for assessing diaphragm activity and function. This study aimed to investigate changes in diaphragm activity during SBT, and to compare diaphragm function between patients with and without SBT success. Forty-five patients undergoing SBT were enrolled. Thickening fraction of the diaphragm was assessed during tidal breathing (TFditidal), and RSBI was measured during 30 min of SBT. Diaphragm function measured by maximum TFdi (TFdimax) and diaphragmatic excursion (DEmax) was also evaluated. TFditidal and RSBI significantly increased during SBT (TFditidal0vs. TFditidal30 = 29.8 ± 13.8 vs. 37.4 ± 13.0%; p < .001, and RSBI0vs. RSBI30 = 64.8 ± 25.9 vs.70.8 ± 29.1 breaths/min/L; p = .034). In SBT failure (n = 13), there was no significant difference in TFditidal compared to SBT success, except at the beginning of the trial (p = .043); however, RSBI significantly increased throughout SBT. No differences in TFdimax or DEmax were observed between groups. Patient inspiratory efforts significantly increased during SBT. TFditidal measured by diaphragm ultrasound could not distinguish between patients with SBT success and failure. RSBI was significantly higher during SBT in patients with SBT failure. •Patient inspiratory effort significantly increases during spontaneous breathing trial (SBT)•Rapid shallow breathing index is still the most reliable index for monitoring during SBT and predicting the weaning outcome.•No difference in TFditidal between patients with SBT success and failure except at the beginning of the trial.•Diaphragm dysfunction may occur in patients with longer duration of mechanical ventilation.