Point-of-Care Ultrasound Techniques for the Small Animal Practitioner

Source: Reproduced with permission of Dr Gregory Lisciandro, Hill Country Veterinary Specialists and FASTVet.com, Spicewood, TX.

Pearl:If an AFS 1, 2 (modified AFS system <3) “small‐volume bleeder” dog or cat without preexisting anemia becomes anemic, the attending clinician should explore other sites as potential sources of hemorrhage, including the retroperitoneal space, pericardial sac, pleural cavity, and lung, using the Global FAST approach along with a good physical exam.

Tables 7.2and 7.3will aid decision making based on the AFAST AFS score in dogs and cats.

In summary, the following general guidelines apply.

Bleeding is most commonly medically treated with titrated fluid therapy, blood transfusion(s), and replacement of clotting factors in patients that require more than one transfusion or that are or have become coagulopathic. Surgery is uncommon so think medical treatment first .

Computed tomography (CT) is the gold standard for detecting injury, whereas AFAST provides indirect evidence through the detection of free fluid.

Radiography is an unreliable test for free fluid not only in terms of its presence or absence but also its inability to semiquantitate volume (Lisciandro et al. 2009).

Any positive is potentially a surgical problem and thus exploratory laparotomy should be considered post resuscitation. There are no veterinary studies evaluating positive AFAST studies and the frequency of medical versus surgical injuries; however, exploratory laparotomy is recommended in people with positive FAST examinations (Udobi et al. 2001).

Computed tomography is the gold standard for detecting injury, whereas AFAST provides only indirect evidence through the imaging of free fluid.

Other imaging options include radiography, which is standard of care for PT, for the detection of pneumoperitoneum, herniations, fractures and body wall abnormalities.

Table 7.3. Flowchart providing general guidelines regarding the decision‐making process for acutely bleeding dogs and cats when applying the abdominal fluid score (AFS) during AFAST. Note the algorithm assumes the patient is noncoagulopathic or, when coagulopathic, the coagulopathy is corrected.

Source: Reproduced with permission of Dr Gregory Lisciandro, Hill Country Veterinary Specialists and FASTVet.com, Spicewood, TX.

Apply the “small‐volume bleeder versus large‐volume bleeder” principle to determine if the case is medical or surgical. The postinterventional patient includes any invasive procedure in which internal bleeding is a possible complication, such as percutaneous aspirations, needle and Tru‐Cut biopsy, laparoscopy, exploratory laparotomy, etc.

In general, the “small‐volume bleeder” (AFS 1 and 2; modified AFS system <3) is not immediately surgical and serial AFAST with an assigned AFS is an important monitoring tool for detecting increasing AFS often before overt decompensation, referred to as the “crump” (Bilello et al. 2011).

In stable AFS 1 and 2 (modified AFS system <3) patients, the author routinely repeats AFAST with an assigned AFS ~1 hour post admission and then again four hours post admission, and then as clinical course dictates.