Tumescent solution is also called “Klein’s Solution” after the physician who characterized the recipe and the use of it.
It’s called “tumescent” because it makes things tumescent, which is a fancy word for swollen. Tumescent is a dilute solution of lidocaine, epinephrine, and sodium bicarbonate that is injected in the subcutaneous tissue (fat). The epinephrine is the most important ingredient as it causes vasoconstriction, this means that the blood loss that could be a big problem for large procedures like burn surgery and liposuction becomes much less of a big deal.
The other interesting thing is that since fat is relatively avascular compared to other tissues, the “safe amount” of tumescent is much higher than what is normally stated for injections of lidocaine or epinephrine.
For example, it was reported by Klein that the toxic dose of lidocaine for tumescent solution is 35 mg/kg of body weight.
There are a few different recipes for tumescent anesthesia, the one presented in the doodle is the one first outlined by Klein, some use more or less lidocaine or epinephrine.
Kucera IJ1, Lambert TJ, Klein JA, Watkins RG, Hoover JM, Kaye AD. Liposuction: contemporary issues for the anesthesiologist. J Clin Anesth. 2006, 18(5): 379-87.
Klein JA. The tumescent technique. Anesthesia and modified liposuction technique. Dermatol Clin. 1990, 8(3): 425-37.
Klein JA. Tumescent technique for local anesthesia improves safety in large-volume liposuction. Plast Reconstr Surg. 1993, 92: 1085-100.
Nevi (or moles) are very, very common. They are generally well-circumscribed dark spots (or “papules” to use the dermatological terminology) that can appear at any time in someone’s life.
Histologically they are composed of groups of melanocytic nevus cells and can be found in the epidermis, dermis or both.
The problem with nevi is that they are pigmented and people tend to get worried about pigmented things on the skin (for good reason as melanoma can be a pretty scary disease).
Common acquired nevi are grouped into three categories (I’ll leave out congenital and dysplastic nevi for now)
Junctional: the nevus cells are completely in the epidermis, just above the dermal-epidermal junction. Clinically they are <1 cm, flat or minimally elevated and dark in colour.
Compound: the nevus cells are in both the epidermis and the papillary dermis (top layer of the dermis), and cross the basement membrane. Clinically they are raised, and a medium-brown colour.
Dermal: the nevus cells are completely in the dermis. Clinically they are raised and almost always pigment less as the cells lose their capacity for melanization when in the dermis. They usually have telangectasia and may or may not have hair. They don’t tend to appear until the 2nd or 3rd decades of life.
Burns are typically classified by their depth into (or through) the skin.
1st degree: just in the epidermis
Pink, hot, no blisters
Like a typical sunburn
2nd degree: into dermis, painful, wet
Superficial: unruptured blisters, hair & glands spared, erythematous (red) but blanch with pressure
Deep: ruptured blisters, hair often gone, can convert to a 3rd
3rd degree: through the dermis aka full thickness
Lack vascularization, dry, leathery, no sensation
Zones of a Burn
A burn isn’t a homogenous spot on the skin; more heat means more damage (who knew!)
40 – 44 C: enzymes malfunction, protein denature
>44 C: damage occurs faster than the cell can handle
Damage keeps going after the heat source is removed
Zone of Coagulation: The cells are dead and their proteins have denatured. Denatured proteins coagulate – think fried eggs. This is what forms the eschar of the burn.
Zone of Stasis: The cells aren’t quite dead but the blood supply isn’t the best. If the circulation gets worse (usually due to vessel constriction and thrombosis) the cells in this area will die too. This is why it can take a couple days for a burn to “declare” itself.
Zone of Hyperemia: “Hyperemia” means an increase in blood flow, in this case because of vasodilation. The cells in this area are alive and generally recover.
The image above shows a superficial 2nd degree burn.
Kawasaki Disease is one of the pediatric rashes that you always need to have in the back of your mind. Most of the time the disease is self-limiting, but the consequences of not catching it are pretty bad (turns out coronary artery aneurysms often lead to things like infarction and DEATH).
Warm CREAM is an unrelated (and somewhat unpleasant) mnemonic to help remember the signs and symptoms of Kawasaki. The “warm” is a fever (one lasting more than 5d) and then you need 4/5 of the other criteria (non-purulent conjunctivitis, rash, palmar erythema/swelling, cervical adenopathy, dry and red mucous membranes, the infamous strawberry tongue). The kid doesn’t need all 4 as he or she is sitting in front of you, but the presentation and the history combined should include those criteria.
Treatment is with high doses ASA and IVIG, you do this to prevent the sequelae of coronary artery aneurysms and myocarditis, and it’s best to get an echo to check up on things.
Hand, foot and mouth syndrome (or disease to all you lay people out there) is a common viral illness, most often caused by coxsackie virus. Generally it affects daycare-aged children (the 1-10ish age group), mostly under the age of 6. The big thing is the fever with a rash on, you guessed it, the palms, soles and in the mouth. Sometimes the rash can also present on the trunk or back as well. The worst part is that the vesicles in the mouth are VERY painful, so it’s not uncommon for kids to want to stop eating or drinking when they have it.