that."
To apply cryo, the clinician guides a probe — a tube within a tube
— to the target nerve. Once in place, the probe's tip is frozen using
carbon dioxide or nitrous oxide, which is then vented up through the
probe. The resulting ice ball on the probe's tip freezes the nerve, inter-
rupting its pain signals to the brain. The ice ball only seems to injure
nerves, not tissue, notes Dr. Ilfeld. Some experts suspect that's
because nerves don't have the level of blood supply (and accompany-
ing heat) that tissue does. That's advantageous because clinicians
"don't have to be particularly concerned with tissue in the immediate
vicinity of the nerve," says Dr. Ilfeld.
He says the risks of cryo, a sterile procedure, are small, and nothing
is injected into the patient. It could be applicable for "niche proce-
dures" like breast, knee or shoulder surgery, he says. "It has to be a
procedure where the person is okay if it lasts months. It decreases
sensation, often to zero, and has the potential to decrease muscle
strength dramatically, if not completely. There aren't many places in
the body where you can do that. It's really most applicable to the
trunk of the body."
• New blocks. QL and TAP blocks are a significant part of regional
anesthesia aimed at the abdominal wall, and providers are doing these
with longer-lasting local anesthetics like liposomal bupivacaine, says
Dr. Dickerson. Newer QL blocks are rising in use, he says: "TAP blocks
have been challenged because there's not a very clear response in
patients that's consistent with how well it's going to cover their inci-
sional pain. With QL blocks, you're going to a space that's more likely
to reach the nerves you're intending to target in more robust fashion. It
seems like it has a more reliable spread in the majority of patients."
Dr. Dickerson says that erector spinae blocks increasingly are being
used to mitigate pain in the thorax. "For surgery on a rib or a chest
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