Clinical Case: Pneumothorax

A 63 year old lady with a history COPD arrives to the emergency department via ambulance acutely short of breath.

She is in respiratory distress with accessory muscle use. Her heart rate is 130, her blood pressure is 90/30, her respiratory rate is 35 and her oxygen saturations are 88% on a 100% non rebreather mask.

You listen to her chest, and you hear decreased breath sounds on the left, and absent breath sounds on the right.

You perform a quick bedside ultrasound of both lungs, starting on the left, that reveals the following images:

 

This is an example of a tension pneumothorax, which requires urgent treatment with needle decompression and chest tube insertion. Bedside ultrasound is a quick diagnostic test to aid in the diagnosis.

The first images are of a normal lung, with pleural sliding seen on 2D images corresponding with respirations. In M-Mode, the seashore sign can be seen, with the appearance of waves in the top half of the image while the bottom half appears like sand.

In a pneumothorax (00:38), however, there is no longer a pleural slide, and there is the more homogenous "barcode sign" in M-Mode.

Although these ultrasound signs can indicate the presence of a pneumothorax, the diagnosis of a tension pneumothorax is based on clinical signs as described above, particularly the respiratory distress and hemodynamic instability.

Procedure: Paracentesis

This video below describes how to use bedside ultrasonography while performing a paracentesis.

With ultrasound, an area with an adequate amount of free fluid can be identified, and the risk of perforating bowel can be decreased. With the use of the abdominal probe, this area can be identified quickly by scanning the abdomen to obtain both transverse and long axis views.

Clinical Case: Empyema

A 47 year old gentleman presents to the emergency department with fevers, shortness of breath and productive cough. He is tachycardic and is requiring supplemental oxygen. You hear crackles and decreased breath sounds at the base of the right lung.

You perform a bedside lung ultrasound which reveals the following image:

This is an example of a loculated pleural fluid which can be detected on ultrasound. These loculations occur in complicated parapneumonic effusions and empyema. Utrasonography plays a key role in both the diagnoses and management of these effusions. Identifying loculations on ultrasound changes management, since a thoracentesis is required in this circumstance. Also, ultrasound-guided thoracentesis allows you to identify a pocket of fluid that is attainable for sampling.

Lung Ultrasound Resource

This resource at Handsonecho by Prof Dr. Daniel Lichtenstein is a great educational resource for lung ultrasound. Included in these short educational videos is the BLUE protocol for acute respiratory failure.

I've also included link to an open access article on lung ultrasound by Prof Dr. Daniel Lichtenstein titled Lung ultrasound in the critically ill.

Procedure: Thoracentesis

Ultrasound is very useful when performing thoracentesis for both confirming the presence of a pleural effusion and for locating the appropriate area for needle insertion. 

This video provides an explanation on ultrasound positioning and landmarking for ultrasound guided thoracentesis.