Ultrasound for Critical Care Physicians: Take a Deep Breath

David Ling, DO

Michel Boivin, MD

Division of Pulmonary, Critical care and Sleep Medicine

University of New Mexico School of Medicine

Albuquerque, NM

A 40 year old man with a past medical history of intravenous drug abuse presented to the emergency department with difficulty walking and lower extremity weakness. He did admit to recent heroin use. He became somnolent in the ED and was given naloxone. However, he did not improve his level of consciousness sufficiently and was intubated for hypercarbia. The patient was transferred to the MICU and was evaluated for respiratory failure. He later that day passed a spontaneous breathing trial after he awoke and was extubated. However, he was soon thereafter was re-intubated for poor respiratory efforts and a weak cough. 

With an unexplained etiology for the respiratory failure, CT of the head, MRI of the brain and lab evaluation were pursued but were negative.  At that point, a bedside ultrasound of the right hemi-diaphragm in the zone of apposition was obtained and is shown below:

Figure 1. Ultrasound of the right hemi-diaphragm at low depth, at the zone of apposition. The diaphragm is visualized above the liver as three parallel echogenic stripes.

Figure 2. M-mode image of the right hemi-diaphragm. The m-mode image is on the left, and the corresponding 2D image is on the right.

What does the video and M-mode of the diaphragm demonstrated above predict for the potential result of the patient’s extubation? (Click on the correct answer for the answer and explanation)

1. Success
2. Failure
3. Has no predictive value

Reference as: Ling D, Boivin M. Ultrasound for critical care physicians: take a deep breath. Southwest J Pulm Crit Care. 2015;11(1):38-41. doi: http://dx.doi.org/10.13175/swjpcc091-15 PDF