and “large‐volume” bleeding (and other forms of nonhemorrhagic effusions) by assigning a score of ½ or 1 dependent on the maximum measured dimension at each AFAST view based on recently published studies (Lisciandro et al. 2015, 2019; Romero et al. 2015). The AFS is validated in either right or left lateral recumbency (Lisciandro et al. 2009). See also Figure 7.3.
Source: Reproduced with permission of Dr Gregory Lisciandro, Hill Country Veterinary Specialists and FASTVet.com, Spicewood, TX. Illustration by Hannah M. Cole, Adkins, TX.
The “small‐volume bleeder versus large‐volume bleeder” principle remains the same with a 0–4 system as published (Lisciandro et al. 2009); however, the addition of the ½ helps better semiquantitate and categorize the bleeding dog and cat (Lisciandro et al. 2019). The modified fluid scoring system may also be used with nonhemorrhagic effusions since any effusion potentially contributes to volume loss in your patient. Clinical judgment always should be considered along with the patient's entire clinical picture; however, this AFS modification provides an option to better categorize bleeding patients and those with other nonhemorrhagic effusions. For example, a dog may have small pockets at the DH, CC, and HRU views of <1 cm which would now be deemed a small‐volume bleeder (if a bleeding case) with a score of 1½ rather than a 3 (see Figure 7.8).
Applying the Abdominal Fluid Scoring System to the Hemoabdomen
The “abdominal” fluid scoring system was purposely named as such and not the “hemorrhage” scoring system to avoid the system being typecast for only hemorrhage. The name, however, seems to have prevented its routine use in bleeding cases despite its documented ability to semiquantitate volume, rapidly categorize the bleeding patient, and help with decision making regarding blood transfusion(s) and exploratory laparotomy. The AFS system furthermore serves to track patients for worsening hemorrhage (or effusions) by increasing AFS, static hemorrhage (or effusions) by no change in AFS, and resolving hemorrhage (or effusions) by decreasing AFS. Knowing the patient's AFS is incredibly helpful for clinicians performing AFAST to place the degree of hemorrhage into clinical context (Lisciandro et al. 2009). The AFS should be used as standard of care, calculated and recorded for all patients having AFAST.
Small‐Volume Bleeders: AFS 1 and 2 (AFS <3)
AFS 1 and 2 (AFS <3) are “small‐volume bleeders” that reliably will not become significantly anemic from their intraabdominal bleed because, simply put, there is not enough intraabdominal hemorrhage to cause anemia (Figures 7.4 and 7.5). Of course, they must remain an AFS of 1 or 2 (AFS <3) on serial AFAST examinations.
If an AFS 1 or 2 (AFS <3) dog or cat is or becomes anemic, then there are four major possibilities.The patient had preexisting anemia.The patient is bleeding somewhere else, emphasizing the importance of the Global FAST approach and a good physical examFigure 7.3. Modification of the AFAST‐applied AFS. The figure shows how size matters, using the AFAST CC view as an example. In (A) the small pocket, anechoic triangulation (circled) would be scored a ½ as a “soft” positive whereas in (B) the larger pocket would be scored a full 1 as a “strong” positive. This visual modification is used at all AFAST views and is an alternative to the measurement modification shown in Figure 7.2.Source: Reproduced with permission of Dr Gregory Lisciandro, Hill Country Veterinary Specialists and FASTVet.com, Spicewood, TX.Figure 7.4. AFAST‐applied AFS and the small‐volume versus large‐volume bleeder principle. Cartoon of a dog in right lateral recumbency and the “small‐volume versus large‐volume” bleeder/effusion principle. In (A) and (B) the AFS is 1 and 2, respectively. Anemia is not expected in AFS 1 and 2 (modified AFS system <3) bleeding patients. In (C) and (D) the AFS is 3 and 4 (modified AFS system ≥3), respectively. These bleeding dogs will predictably be or become anemic from the intraabdominal volume of blood. The same principle holds true for cats. The AFS is validated only in lateral recumbency. CC, cysto‐colic view; DH, diaphragmatico‐hepatic view; HRU, hepato‐renal umbilical view; SR, spleno‐renal view.Source: Reproduced with permission of Dr Gregory Lisciandro, Hill Country Veterinary Specialists and FASTVet.com, Spicewood, TX. Illustration by Hannah M. Cole, Adkins, TX.Figure 7.5. AFAST‐applied AFS system and the small volume versus large volume principle. Cartoon of a dog in left lateral recumbency and the “small‐volume versus large‐volume” bleeder/effusion principle. In (A) and (B) the AFS is 1 and 2, respectively. Anemia is not expected in AFS 1 and 2 (modified AFS system <3) bleeding patients. In (C) and (D) the AFS is 3 and 4 (modified AFS system ≥3), respectively. These bleeding dogs will predictably be or become anemic from the intraabdominal volume of blood. The same principle holds true for cats. The AFS is validated only in lateral recumbency. CC, cysto‐colic view; DH, diaphragmatico‐hepatic view; HRU, hepato‐renal umbilical view; SR, spleno‐renal view.Source: Reproduced with permission of Dr Gregory Lisciandro, Hill Country Veterinary Specialists and FASTVet.com, Spicewood, TX. Illustration by Hannah M. Cole, Adkins, TX.Hemodilution has occurred from fluid therapy, which is much less common than a couple of decades ago because of more recently taught titrated fluid therapy.Lab error.
Large‐Volume Bleeders: AFS 3 and 4 (AFS ≥3)
AFS 3 and 4 (AFS ≥3) are “large‐volume bleeders” that are or will reliably become anemic from their intraabdominal bleed because, simply put, there is enough intraabdominal blood to cause anemia (see Figures 7.4 and 7.5).
Generally expect a 20–25% decrease from baseline packed cell volume (PCV) for all dogs and cats.
In the author's experience, ~1 in 4–5 dogs (unknown in cats) will become severely anemic (dogs PCV <25%; cats PCV <20%), requiring a blood transfusion(s).
Surgical intervention varies with patient subsets (Table 7.2).
A hemoabdomen decision‐making algorithm for correlating the AFS to the anticipated degree of anemia and decision making in different patient subsets is provided in Table 7.3.
Importance of the Serial Exam
Serial AFAST with an assigned AFS is key for monitoring changes, and for better detecting the “small‐volume bleeder” that is becoming a “large‐volume bleeder” often before overt patient decompensation, referred to by some as the “crump factor” (Bilello et al. 2011) (see Figure 7.9). Veterinarians using the AFAST and AFS approach have advantages over human medicine, in which hemorrhage scoring systems are not routinely implemented despite the fact that occult or unrecognized ongoing hemorrhage is the top cause of death next to traumatic brain injury in hospitalized human trauma patients within their first 48 hours of care (Bilello et al. 2011; Sobrino and Shafi 2013). Moreover, the most important intervention that prevented the “crump factor” in people with prehospital hypotension was the “liberal use of FAST”
