Focused assessment with sonography in trauma (FAST) for the regional anesthesiologist and pain specialist

Abstract

This article in our point-of-care ultrasound (PoCUS) series is dedicated to the role the focused assessment with sonography in trauma (FAST) exam plays for the regional anesthesiologist and pain specialists in the perioperative setting. The FAST exam is a well-established and extensively studied PoCUS exam in both surgical and emergency medicine literature with over 20 years demonstrating its benefit in identifying the presence of free fluid in the abdomen following trauma. However, only recently has the FAST exam been shown to be beneficial to the anesthesiologist in the perioperative setting as a means to identify the extravasation of free fluid into the abdomen from the hip joint following hip arthroscopy. In this article, we will describe how to obtain the basic FAST views (subcostal four-chamber view, perihepatic right upper quadrant view, perisplenic left upper quadrant view, and pelvic view in the longitudinal and short axis) as well as cover the relevant sonoanatomy. We will describe pathological findings seen with the FAST exam, primarily free fluid in the peritoneal space as well as in the pericardial sac. As is the case with any PoCUS skill, the application evolves with understanding and utilization by new clinical specialties. Although this article will provide clinical examples of where the FAST exam is beneficial to the regional anesthesiologist and pain specialist, it also serves as an introduction to this powerful PoCUS skill in order to encourage clinical practitioners to expand the application of the FAST exam within the scope of regional anesthesia and pain management practice.

Point-of-Care Ultrasound (POCUS) for the Cardiothoracic Anesthesiologist

“…FAST is a commonly used diagnostic modality in trauma patients to evaluate for intrabdominal fluid, as well as to guide surgical interventions. 91,92 In the postoperative setting, FAST can be used rapidly to assess for intra-abdominal fluid collections in the workup for hypotension. 93 The FAST examination (see Table 11) can be performed easily at the bedside and repeated according to the clinical context to guide continued clinical management.…”

American Society of Regional Anesthesia and Pain Medicine expert panel recommendations on point-of-care ultrasound education and training for regional anesthesiologists and pain physicians—part I: clinical indications

“…95 Gastric POCUS is most useful when there is clinical uncertainty regarding the status of stomach contents, in other words, when the pretest probability of a 'full stomach' is close to 50%. 13 96 97 In a prospective study with a simulated clinical scenario with a pretest probability of 'full stomach' of 50%, a positive gastric ultrasound examination increased the post-test probability of a full stomach to over 95%, and a negative test decreased the post-test probability to 0.1%. 98 Additionally, bedside gastric ultrasound has been shown to change anesthetic management in two-thirds of patients who have not followed fasting instructions before elective surgery 99 100 and in pediatric patients undergoing urgent surgery.…”

“…13 89 96 97 103 104 114 A 'full' or 'not empty' stomach has evidence of solid particulate content (mixed echogenicity), thick (hyperechoic) fluid or a volume of clear fluid in excess of normal baseline gastric secretions (>1.5 mL/kg) (figure 5). 13 96 97 103 104 114 Patient position affects antral size as the stomach's contents pool in the most dependent areas. A more accurate evaluation of the antrum and gastric content is obtained in the right lateral decubitus (RLD) or the semirecumbent position with the head elevated at 45°, as the supine position can underestimate gastric 103 104 112 115 Given these positional differences, a semiquantitative three-point grading system can be used to assess the presence or absence of clear fluid in the supine and/or RLD positions.…”

“…4 Based on these recommendations, there exist guidelines for training, competency and credentialing in POCUS in emergency medicine 5 and critical care medicine, 6 7 and there is currently a work product for POCUS available through the American Society of Anesthesiologists (ASA). 8 Despite the availability of significant resources in the form of numerous live courses 9 and an educational review series on POCUS, [10][11][12][13][14][15] no specific guidelines or recommendations exist on the use of POCUS for regional anesthesiologists and pain physicians. Given ASRA's early leadership in providing recommendations for procedural-based bedside ultrasound in the form of ultrasound-guided regional anesthesia and ultrasound-guided interventional pain procedures, there was a call to address the need for formal POCUS recommendations.…”

Role of diagnostic point-of-care ultrasound in preoperative optimization: a narrative review

“…In patients presenting with trauma, the Focused Assessment with Sonography for Trauma (FAST) examination is widely used as a bedside tool to evaluate for free fluid in the pericardium, abdomen, and the pelvis 18…”