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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 funny but you started at the costal arch and hypaxial muscles looking for the left kidney, not realizing the probe has made it to the midline at the umbilicus (by drifting). No wonder you cannot find the left kidney! If you double‐check yourself by frequently looking at the screen and then at the probe's external location on your patient, you will get to where you want to go much faster! This also occurs commonly while performing Vet BLUE in standing patients. You think you are at the Caudodorsal Vet BLUE lung region but the weight of your hand has brought you close to the Middle Vet BLUE lung region.

The best way to prevent drifting is to routinely “kickstand” out a finger that solidly touches your patient’s body wall (or have another comfortable part of your hand against the patient's body wall) (Figure 5.9).

Figure 5.8. When extending the foreleg, don’t touch the paw! Gently extend the foreleg with your helper hand placed near the elbow and away from the paw. The paw is sensitive and you may create an uncooperative patient (e.g., may bite, may become resistant to restraint, may become tachycardic) by triggering a negative response. Stay near the elbow. Shown is the acquisition of the right Vet BLUE cranial lung region view.

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

Figure 5.9. “Kickstand” your probe hand to prevent drifting. Having some part of your probe hand in contact with the patient will prevent drifting, which is when the sonographer is focused on the screen and unaware that the weight of their probe hand has moved the probe to a different acoustic window. In (A) the probe hand is not braced against the patient, so the sonographer is susceptible to drifting. In (B) the fingers are comfortably spread in contact with the patient's body, thus preventing drifting. Common views for drifting are especially during Vet BLUE and the least gravity‐dependent SR and HR views.

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