eFAST/POCUS

View The Full Pathway

Yes

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Over the past 2 decades, bedside ultrasonography has been increasingly used to diagnose traumatic pneumothorax. Ultrasound is primarily incorporated into the Advanced Trauma Life Support® (ATLS®) algorithm in the form of the bedside FAST examination. The eFAST also incorporates sonographic examination of the pleural interface. When using ultrasound, several important examination findings indicate the presence of a pneumothorax. Lung sliding is a phenom­enon seen when a high-frequency linear probe is applied to an intercostal space and the patient is asked to breathe normally; in a normal lung, the relative move­ments of the visceral and parietal pleura appear with inspiration and expiration. Comet-tail artifacts can also be seen at the pleural interface in a normal lung. In the setting of pneumothorax, lung sliding and comet-tail artifacts are absent. (See Figure 4.)

A Cochrane systematic meta-analysis of studies evaluating the test characteristics of bedside ultrasound compared to CXR for the diagnosis of traumatic pneumothorax found that while specificities were similar, ultrasound was more sensitive than CXR, decreasing the risk of missing a traumatic pneumothorax and delaying time to treatment. Ultrasound was found to have a sensitivity of 0.91 and a specificity of 0.99, compared to a sensitivity of 0.47 and specificity of 1.00 for supine CXR. In addition, eFAST evaluation of pneumothorax by experienced clinicians can take less than 1 minute at the bedside, which is a critical time savings in the survey of trauma patients who may decompensate rapidly. While there are concerns about the accuracy of ultrasound when performed by clinicians who are less experience, the data are limited in this group. One study by Brook et al found that radiology residents were reasonably able to detect moderate pneumothoraces using eFAST, although this was neither sensitive nor specific for ruling out small pneumothoraces.

For tension pneumothoraces and larger pneumothoraces in symptomatic patients, TT is the definitive treatment for air evacuation. The chest tube should be placed at the midaxillary line in the fourth or fifth intercostal space with the tube directed anteriorly to allow for drainage of the pneumothorax. Standard chest tube size ranges from 28F to 40F; pigtail chest tube size generally ranges from 8F to 20F.

Positioning and adequate analgesia are central to successful placement of a chest tube. The patient’s arm should be positioned above the head to allow full access to the lateral chest wall. The skin should be anesthetized where the incision will be made, and lidocaine should be administered along the entire tract that the chest tube will traverse, from skin to parietal pleura. The rib periosteum and the parietal pleura are pain-sensitive structures that require a large amount of local anesthetic.

Patients undergoing TT should be counseled on tube-related complications, as well as the possible need for the insertion of additional chest tubes. (See Table 2.) The most common complications associated with chest tube insertion are bleeding and intercostal neuralgia, although there are also more-severe and morbid complications that can occur due to improper positioning or premature tube removal. Risk of damage to surrounding structures can be minimized with proper insertion technique. Although re-expansion pulmonary edema is a rare complication, it carries a high degree of morbidity and mortality.

Data from Mohammed HM. Chest tube care in critically ill patient: a comprehensive review. Egyptian Journal of Chest Diseases and Tuberculosis. 2015;64(4):849-855.