Intercostal Muscle Function During Noninvasive Ventilation and Acute Hypercapnic Respiratory Failure.

Area of Science:

• Critical Care Medicine
• Respiratory Physiology
• Point-of-Care Ultrasound

Background:

• Noninvasive ventilation (NIV) is a standard treatment for respiratory failure.
• Diaphragm ultrasound is used to assess mechanical ventilation outcomes, but intercostal muscle ultrasound data are limited.
• Accessory muscle activation, including intercostal muscles, occurs with increased work of breathing.

Purpose of the Study:

• To investigate the association between intercostal muscle thickening fraction (TF) and NIV failure in hypercapnic respiratory failure patients.
• To determine if ultrasound-assessed intercostal muscle TF can predict NIV failure.

Main Methods:

• 158 critical care patients receiving NIV for hypercapnic respiratory failure were enrolled.
• Intercostal muscle TF was measured using ultrasound on admission (day 0) and day 1.
• NIV failure was defined as requiring invasive mechanical ventilation or death.

Main Results:

• 30 out of 158 subjects experienced NIV failure.
• Intercostal muscle TF was significantly higher in the NIV failure group on both day 0 and day 1.
• An intercostal muscle TF cutoff of 12% on admission was associated with NIV failure, even after adjusting for severity scores (APACHE II, SOFA).

Conclusions:

• Intercostal muscle TF measured by ultrasound is positively related to NIV failure.
• Increased intercostal muscle TF predicts NIV failure in critical care patients with hypercapnic respiratory failure.
• Ultrasound assessment of intercostal muscle thickening may aid in predicting NIV outcomes.