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It is imperative to not only record the AFS but also locations of where the patient is positive and negative. This is important because the locations of AFAST‐positive views in lower‐scoring “small‐volume bleeders” may be helpful for the localization of the bleeder (Table 7.4). For example, consider a hit‐by‐car dog or cat with an AFS of 1 at the AFAST DH view that continues to bleed with an increase in AFS to 3 or 4 and that despite blood transfusions becomes a surgical case. Logic would dictate that the source of intraabdominal bleeding is likely associated with the liver and its vasculature. This information would potentially better prepare the surgeon for the anticipated type of injury, such as liver laceration, hepatic venous or vena caval injury, and for the needed procedure(s) as well as relevant resources. On the other hand, in the same trauma scenario the AFS 1 is positive at an AFAST view further caudally, such as the CC or HR umbilical view, and now logic would dictate that the source of bleeding would be more likely intestinal tract or spleen. Thus, the definitive procedure would likely be less technically challenging than a liver laceration or vascular hepatic injury.

Table 7.4. Possible sources of abdominal bleeding on AFAST views.

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

View	Possible source
DH	LiverVascularCaudal vena cavaHepatic vesselsPortal vessels
SR, HR, SR5th, HR5th	Spleen (SR, SR5th)Liver (HR, HR5th)AdrenalOvaryVascularCaudal vena cavaAortaRenal vesselsVertebrae
CC	Small intestineLarge intestineReproductive tractUterusProstateVascularCaudal vena cavaAorta
HRU, SRU	LiverSpleenUterusGastrointestinal tract

In nontrauma, another example would be a postovariohysterectomy bleeding case with an AFS of 1 that is positive at the SR view. Let's say that over time, the patient progresses to an AFS of 3 or 4 that requires surgical exploratory. Logic would dictate the source of bleeding is most likely in the vicinity of the SR view and the left ovarian pedicle would be suspect. This information would again help direct the surgeon to that region as initially AFAST positive for the source of bleeding. In fact, for bleeding postoperative ovariohysterectomy surgeries, the AFAST acoustic windows are in regions of the left ovarian pedicle (SR view), the right ovarian pedicle (HR5th bonus view), and the uterine stump (CC view), which is important to consider in “small‐volume bleeders” that progress to “large‐volume bleeders” requiring surgical intervention. The upshot is that the sonographer should record both the AFS and specifically what AFAST views are positive and negative to maximize patient information as dictated in AFAST goal‐directed templates (see last section of this chapter).

Pearl: Use the AFAST and AFS system as a postinterventional exit exam evaluation, e.g., postoperative and postpercutaneous ultrasound‐guided procedures, before patients are sent home to ensure no occult bleeding is occurring. The use of this strategy is more sensitive than a physical exam, vital signs, and packed cell volume and total solids.