updates

perhaps, i ought to give a more personal view of things from a medical student's perspective... but as it is, between studying finals, preparing for tennis competition, and struggling to revise german, there simply isnt time, for now. i trust that there will be, in 2 weeks' time, when we start our clerkship.

meanwhile here are others' voices, from all over the world :P

medicaltraining.blogspot.com
medicalstudentblogs.blogspot.com

bis zum naechtens mal, tchuess!

muscle relaxants

use of succinylcholine in children should be limited to situations involving emergency intubation, or instances where immediate securing of the airway is necessary (e.g. laryngospasm, difficult airway, full stomach or ..??)

non-depolarizing muscle relaxants take longer to initiate (at least 30mins)
and can be categorized into: benzylisoquinolone, steroidal

benzylisoquinolone --> histamine release
steroidal --> vagol blockade (HR increases i.e. pancuronium)

~~~

atracurium: hoffman elimination (1/3 in plasma)
- metabolic product: laudanosine (toxic)
- associated with cns excitation, extremely
high dose or hepatic failure
- not recommended for use in asthmatic patients, due to increased
risk of bronchospasm

cisatracurium: hoffman elimination (mostly in plasma)
- greater potency, insignificant histamine release, less
laundanosine than atracurium

cisatracurium >>>> atracurium.

STEROIDAL
pancuronium: metabolized by the liver
hypertension and tachycardia due to vagal blockade and
catecholamine release from adrenergic nerve endings (however,
this is good for patients with low bp)

rocuronium: onset is FAST (suitable for rapid sequence intubation 1~1.5min)

Skin Tumors - Malignant

+ Actinic Keratosis
= Pathogenesis: Long-term sun-exposure
= Clinical Presentation: Pink/brown, rough patches, of about 1cm in
diameter, ulceration, easy bleeding
= Histology: Budding, atypia (hyperchromatic change), dermis with
lymphocyte infiltration
= DDX: seborrheic keratosis, verruca vulgaris, keratoacanthoma, bowen's
disease, squamous cell carcinoma
= TX: surgery, electrodessication, curretage, liquid nitrogen cryotherapy
(surgery preferred as biopsy can be done simultaneously)

+ Bowen's Disease (intra-epidermal carcinoma)
= Pathogenesis: might be due to arsenic poisoning (esp when multiple
lesions are present. single lesions are commonly due to
sun exposure)
= Clinical Presentation: pink/brown patchy lesion with crusting and
bleeding.
= Histology: entire skin layer involved. dermis with leukocyte
infiltration.
= DDX: psoriasis, discoid eczema, superficial BCC

+ Basal Cell Carcinoma
= Pathogenesis: sun exposure, long-term friction, xray. aresenic, genetic
= Clinical Presentation: nodular ulcerative type most common (rodent ulcer)
pigmented tyupe (most common). fibrosing type,
superficial type.
= TX: MOHS surgery, simple excision (most common), radiation therapy,
oral retinoids, systemic chemotherapy

+ Squamous cell carcinoma
= Pathogenesis: UV exposure, radiation,

zzz

+

lumps and bumps (benign)

+ pyogenic granuloma
- no sign of infection
- capillary hemangioma

+ glomus tumor
- AV shunts
- painful

+ lymphatic malformation (lymphangioma)
- frog-spawn

BENIGN CYSTS & PSEUDOCYSTS
+ epidermal inclusion cyst
-follicular infundibulum (cyst wall true epidermis, containing foul-smelling
macerated keratin substance
-presence might be linked to trauma
-MILIUM - small form of inclusion cyst
- TX: entire cyst with its lining should be removed surgically

+ trichilemmal cyst (pilar cyst)
- cystic content is made up of amorphous material, granular layer not obvious

+ digital myxoid cyst
- pseudocyst occuring over DIP

BENIGN TUMORS of EPIDERMIS and its APPENDAGES
+ seborrheic keratosis
= epidermis - scaling, well-marginated papule or plaque.
= thickened epidermis containing horned pseudocysts. benign squamoid and basaloid
proliferation. basal layer hyperproliferation.
= where? middle-aged old patients on head neck and trunk (sun-exposure)
= appearance? flesh-colored, smooth to warty crumbly texture, stuck-on
appearance.
= LESER TRELAT sign (massive appearance of seborrheic keratosis in old-age might
be a sign of GI malignancy ~% correlation unknown)
= STUCCO KERATOSIS (variation)
= DDX: lentigo maligna and lentigo maligna melanoma (shave biopsy), bcc,
hidroacanthoma simplex/eccrine poroma, fibroepithelioma of pinkus,
epidermal nevus (pigmented nevocellular nevus)
= TX: curettage

+ Keratoacanthoma
= Appearance: Epidermal shoulders (dome-shaped) and central keratotic plug.
= Distribution: Upper trunk and of 6 wks duration
= Histology: keratin plug, thin shoulder of normal epidermis, horn cyst, MNC
infiltrate
= DDX: squamous cell carcinoma

+ trichoepithelioma
= Appearance:

+ syringoma
= benign ademoa of the eccrine ducts
= Distribution: family history, women @ beginning of puberty
= disseminated syringoma on chest wall
= TX: laser removal

+ sebaceous hyperplasia
= cause: chronic sun exposure (photodermatitis)
= appearance: yellow papule, central umbilication, contains sebaceous material,
bv dilatation (telangiectasia)
= distribution: face

+ nevus sebaceous
= appearance: yellowish plaque lesions of characteristic orange color, hairless
= distribution: scalp
= note: 10% of pateitns can be expected to develop bcc in the lesion, therefore
excision is recommended at around puberty

+ epidermal nevus
= developmental (hamartomatous) disorder
= histology: hyperplasia of epidermal structures (epidermis and adnexa), no
nevocellular

+ Becker's nevus (variation of epidermal nevus)
= distribution: dermatone (t2 ~ t4, maybe c6-c8)
= appearance: dermatomal distribution on chest,
= tx: laser treatment

BENIGN DERMAL TUMORS
+dermatofibroma
= appearance: dome-shaped, slightly erythematous and tan nodule with a button-like,
firm appearance. "dimple sign". might be pigmented.

+hypertrophic scars
= appearance: broach raised scar developing at site of injury (no crossing over to normal skin

+keloid
= histology: epidermis atrophic,
= tx: combined cryotherapy and intralesional triamcinolone.
surgical excision, silicone cream nd silicone gel sheet.

+lipoma
= histology: normal epidermis, dermis impinged upon by an encapsulated tumor
contains large amounts of lipocytes and telangectasia
= appearance? soft swelling that moves around when pressed

+skin tag (soft fibroma, acrochondron, cutaneous papilloma)
= distribution: more common in females and in obses paeitnts, often in
intertriginous areas (axillae, inframammary, groin)
= TX; excision!

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

NOTE: dermal nodules without specific activity is


CORNS and CALLUSES
= keratotic lesions resulting from repeated trauma
= HARD corns - dorsal aspects of the toes, SOFT corns - interdigital web
spaces
= salicylic acid, urea

Meconium Aspiration

What on earth is meconium, anyway?
The first intestinal discharge of the newborn, made up of:
1)epithelial cells 2)fetal hair 3)mucus 4)bile

While usually passed out by the newborn within 48 hours of birth, intrauterine stress may cause inutero passage of meconium into the amniotic fluid, and is a warning sign of fetal distress. As one can imagine then, accidental aspiration of meconium must not be very pleasant.

Aesthetics aside, meconium aspiration causes airway obstruction and intense inflammatory reaction resulting in severe respiratory distress.

Happening in mostly term and postterm infants, risk factors for meconium aspiration include:
1)postterm pregnancy 2)abnormal fetal heart rate 3)preeclampsia-eclampsia
4)maternal hypertension 5)maternal diabetes mellitus 6)SGA infants 7)biophysical profile =<6 8)Maternal heavy smoking, chronic respiratory disease, or cardiovascular disease

Pathophysiology (why and how it happens):
Caused namely by asphyxia and other forms of fetal stress, we see an increase in intestinal peristalsis, coupled with relaxation of the external anal sphincter, leading to passage of meconium.

What happens next:
Upon aspiration of meconium, airway obstruction and chemical pneumonitis ensues:

AIRWAY OBSTRUCTION:
Comes in the form of total and partial obstruction.
Total obstruction leads to atelectasis and Partial obstruction results in airtrapping and hyperexpansion (increasing risk of air leak)

CHEMICAL PNEUMONITIS:
Bronchiolar edema and narrowing of the small airways resulting in uneven ventilation. Areas of partial obstruction and superimposed pneumonitis causes severe CO2 retention and hypoxemia. This causes increase in pulmonary vascular resistance.

new blog!

im going to convert this blog into my little webspace on medical snippets. partly because i think it is called for, and mostly because i have a perpetual NEED to go online and type random things prior to the exams (i.e. now), and so, why not type something that's USEFUL instead of systemically and obsessively-compulsively sifting through my gmail and refreshing facebook every 5 minutes? :P