Invasive procedures are frequently performed in the emergency department (ED). Traditionally, these procedures have been performed by emergency physicians who relied on physical assessment for making the correct diagnosis and surface landmarks for determining the correct approach. In recent years, the use of point-of-care ultrasound (POCUS) has been incorporated into clinical practice to guide the performance of a variety of invasive procedures.
The use of ultrasound guidance, either dynamic or static, to perform certain procedures can decrease complications when utilized correctly. Before performing any procedure under ultrasound guidance, it is imperative that clinicians have a thorough understanding of sonographic anatomy, know the basic principles of ultrasound, and have practical training with phantoms or models to develop the hand–eye coordination required. Lack of familiarity with ultrasound and the orientation of the image on the screen can lead to complications, even in the hands of a physician skilled at performing the procedure in a “blind” fashion.
Ultrasound is a highly operator-dependent technology and the success of an ultrasound-guided procedure will depend on the skill of the physician performing the procedure. The amount of training required to successfully perform these procedures has not been well defined in the literature. In the 2016 American College of Emergency Physicians (ACEP) Emergency Ultrasound Guidelines, performance of a minimum of five, quality reviewed, ultrasound-guided procedures or completion of a module on ultrasound-guided procedures with simulation on a high-quality ultrasound phantom is recommended for hospital privileges.1 However, it is acknowledged that the training process for POCUS should move beyond strict numbers and include experiential and competency components.
DYNAMIC AND STATIC GUIDANCE
Ultrasound guidance decreases serious complications, such as pneumothorax and bleeding, and lowers health-care costs associated with invasive procedures such as paracentesis and throacentesis.2 Procedures can be performed using either dynamic or static ultrasound guidance. Dynamic ultrasound guidance entails performing the procedure while imaging the target and needle in real-time during the procedure. Static ultrasound guidance entails performing the procedure in the traditional fashion after the anatomy, along with any pathology, has been mapped by ultrasound and the entry point marked.
The decision to perform a procedure under dynamic or static ultrasound guidance is based on the procedure itself. Procedures involving small target structures or procedures requiring precise placement of the needle are best performed under dynamic guidance. Procedures such as paracentesis, thoracentesis, and abscess drainage are frequently performed using static guidance since the fluid collections tend to be larger, and once anatomy and pathology are marked out, it is typically safe to proceed blindly.
Transducer selection is based on the size of the scanning area and the depth of the target structure. The depth of the target structure determines the frequency selection. Superficial target structures are best imaged using high-frequency ...