Source: Courtesy of Dr Gregory Lisciandro, Hill Country Veterinary Specialists and FASTVet.com, Spicewood, TX.
Fan, Rock Cranially, and Return for AFAST Views
As a result of work by Boysen et al. in the original FAST translational study from humans to dogs, we have simplified and standardized the probe maneuver for AFAST as “fan, rock cranially, and return to your starting point” because 397/400 views matched for detecting free intraabdominal fluid when comparing longitudinal to transverse orientation (Boysen et al. 2004). And most abdominal organ anatomy during AFAST is easier to recognize in longitudinal and sagittal planes. Consider transverse orientation as an add‐on skill (Figure 5.5).
Playing on the Short‐axis and Long‐axis TFAST Lines
In contrast to many echocardiography courses that begin with the long‐axis cardiac views, we begin TFAST with short‐axis views. Importantly, if the sonographer can grasp the “short‐axis line” and “long‐axis line” concept and fan the probe while staying on these lines, echocardiography views are learned more quickly and acquired more consistently by the noncardiologist sonographer (Figure 5.6). Without even looking at the screen, knowing you are on these TFAST cardiac lines will optimize success. We could literally teach you from across the room, without any screen knowledge, by just seeing whether or not you are maintaining the ultrasound beam on these lines while fanning from the apex to the base on short‐axis, and from side to side on long‐axis using our clockface approach (see Figures 17.25 and 17.26).
Figure 5.5. Anatomy generally better recognized in longitudinal (sagittal) orientation than transverse. In (A) the kidney is generally better recognized and then interrogated by fanning through longitudinal planes than in (B), showing the kidney in less recognizable transverse orientation.
Source: Courtesy of Dr Daniel Rodriguez, Mexico City, Mexico.
Figure 5.6. Short‐axis and long‐axis lines for echo views. If only someone had told me this back in 2005, to religiously keep the probe head parallel to the short‐axis (cardiac) and long‐axis (cardiac) lines while fanning, I would have gained proficiency so much faster. Trust these lines and fan while staying on them to achieve your echo views. We can tell from across the room whether or not you are successful by seeing if you are on these lines using a clockface orientation approach (Figures 17.25 and 17.26). Wander from them and everything gets goofy.
Source: Courtesy of Dr Gregory Lisciandro, Hill Country Veterinary Specialists and FASTVet.com, Spicewood, TX.
Failure to Maintain Probe–Skin Contact with the Patient
Every time you lose probe–skin contact with your patient, you delay the imaging and have to reestablish your acoustic window, losing precious time and potentially increasing risk in hemodynamically fragile (and stressed) patients. There are several recommendations that involve your nonprobe “helper hand,” placed into two broad categories: (1) maintaining probe–skin contact (acoustic window) by moving your patient's loose skin with the probe, and (2) maintaining probe–skin contact (acoustic window) by keeping your patient from swaying and at the same time stabilizing the probe against your patient's body.
We have found that the sonographer may take advantage of the patient's loose skin by moving the probe and skin together, and moving nearby less haired skin over the external landmark for your desired acoustic window. An example would be while doing Vet BLUE lung ultrasound, without losing probe–skin contact and your acoustic window, slide the probe together with the loose skin one intercostal space caudal and one intercostal space cranial when possible to cover the respective intercostal spaces at each respective Vet BLUE region. Another example is at the SR and HR views where the skin ventral to these views is often more sparsely haired, so your helper hand's thumb can lift or move this region dorsally over your external landmark of the costal arch and sublumbar muscles. By taking advantage of the sparsely haired area, imaging quality is markedly improved, especially in a thickly coated golden retriever, border collie or Siberian husky (see Figures 5.1 and 5.4). Another AFAST location is the CC view. Placing the probe laterally but closer to the midline where there is obvious sparsely hair coated skin markedly improves the image.
Regarding maintaining probe–skin contact, we have some pearls. First, when your patient is standing during the Global FAST approach, use your helper hand to “V trough” the patient by holding both sides of the sternum (Figure 5.7). This is especially helpful for evaluating your TFAST pericardial site (PCS) views but may also be used during Vet BLUE. Second, use your helper hand to brace your probe against the thorax or abdomen for better control of fine probe maneuvers.
Figure 5.7. V trough your patient with your nonprobe helper hand. Your nonprobe helper hand is used as a V trough to keep your patient from swaying and maintaining probe to skin contact. Every time you lose contact, you potentially lose your good acoustic window and precious time. As much as possible, keep all four legs of your patient on the table.
Source: Courtesy of Dr Gregory Lisciandro, Hill Country Veterinary Specialists and FASTVet.com, Spicewood, TX.
Third, as often as possible, let the patient have all four legs on the exam tabletop (see Figures 5.4 and 5.7). The only time a three‐legged approach is mandatory is for the Vet BLUE cranial lung region for defining the cranial transition zone of soft tissue of the neck and then sliding caudally to image the first three intercostal spaces. Most of the time, the standing TFAST PCS views and imaging the heart may be done with all four legs on the exam table. By this approach, the patient is not swaying and feels more secure than lifting and extending a foreleg off the table. Fourth, when lifting and extending a foreleg, we lift and extend near the patient's elbow, especially for dogs. Many dogs do not like their paws being handled and associate it with the unpleasant experience of having their nails trimmed (Figure 5.8). Thus, by handling the paws, your patient becomes restless, wary, and tachycardic and may try to bite you!
Other Probe–Skin Contact Issues
Not Being Aware of Drifting
Drifting is the phenomenon of looking intensely at the ultrasound screen and not realizing that the weight of your hand and gravity has taken you to a place where no man (or woman) has gone before – a bit of an exaggeration which will hopefully help you remember this very common mistake. The Star Trek phrase sounds
