PMC Residency Entrance Exam flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Anion gap

Serum sodium minus the sum of chloride and bicarbonate; normal is 8-12 mEq/L; elevated in ketoacidosis, lactic acidosis, renal failure, and toxic ingestions.

Parkland formula

Burn resuscitation formula: 4 mL lactated Ringer's × body weight in kg × percent total body surface area burned in 24 hours, with half given in the first 8 hours.

Naegele's rule

Estimated date of delivery is calculated from the first day of the last menstrual period plus 7 days minus 3 months, adding a year when needed.

APGAR score

Newborn assessment at 1 and 5 minutes scoring Appearance, Pulse, Grimace, Activity, and Respiration from 0 to 2 each; a total of 7 or more is normal.

Michaelis-Menten Km

The substrate concentration at which an enzyme reaches half its maximum velocity; a low Km indicates high substrate affinity, and competitive inhibitors increase Km without changing Vmax.

Incidence versus prevalence

Incidence counts new cases arising in a population over a period; prevalence counts all existing cases at a point in time and approximates incidence multiplied by mean disease duration.

Serotonin syndrome

Toxicity from serotonergic drugs causing clonus, hyperreflexia, agitation, and hyperthermia; treated with cyproheptadine and supportive care after stopping the offending agent.

Rigor mortis

Postmortem stiffening of muscles from ATP depletion; it begins 1-2 hours after death, peaks around 12 hours, and resolves by 24-48 hours depending on ambient temperature.

Papilledema

Bilateral optic disc swelling caused by raised intracranial pressure; visual acuity is typically preserved while the blind spot enlarges, and urgent neuroimaging is required.

Malignant hyperthermia

Life-threatening hypermetabolic reaction to volatile anesthetics or succinylcholine marked by rising end-tidal carbon dioxide, rigidity, and hyperthermia; treated with dantrolene.

Shock index

Heart rate divided by systolic blood pressure; a value above 0.9 suggests significant occult hemorrhage even when blood pressure still appears normal.

Preeclampsia

New hypertension of 140/90 mmHg or higher after 20 weeks of gestation with proteinuria of 300 mg per 24 hours or evidence of organ dysfunction; delivery is definitive treatment.

Kawasaki disease

Febrile vasculitis of childhood with fever for 5 days or more plus 4 of 5 mucocutaneous criteria; treated with intravenous immunoglobulin and aspirin to prevent coronary aneurysms.

Tumor suppressor genes

Genes such as p53, Rb, and APC that normally restrain cell growth; carcinogenesis requires loss of function of both alleles, consistent with the two-hit hypothesis.

Positive predictive value

The proportion of people with a positive test result who truly have the disease; unlike sensitivity and specificity, it rises as disease prevalence increases.

Neuroleptic malignant syndrome

Idiosyncratic reaction to antipsychotics with rigidity, hyperthermia, autonomic instability, and elevated creatine kinase; treated by stopping the drug and giving dantrolene or bromocriptine.

Organophosphate poisoning

Cholinesterase inhibition causing miosis, salivation, lacrimation, bradycardia, bronchorrhea, and fasciculations; treated with atropine and pralidoxime.

Acute angle-closure glaucoma

Ocular emergency with a painful red eye, fixed mid-dilated pupil, hazy cornea, and high intraocular pressure; treated with topical and systemic agents plus laser iridotomy.

ASA physical status

Preoperative classification from I to VI: I is healthy, II mild systemic disease, III severe systemic disease, IV constant threat to life, V moribund, and VI brain-dead organ donor.

Diabetic ketoacidosis

Metabolic emergency with glucose above 250 mg/dL, pH below 7.3, bicarbonate below 18 mEq/L, and ketonemia; managed with isotonic saline, insulin infusion, and potassium replacement.

Sentinel lymph node biopsy

Injection of dye or radiotracer to identify the first draining lymph node; standard for staging a clinically node-negative axilla in breast cancer and melanoma.

Late decelerations

Fetal heart rate decelerations that begin after the contraction peak and return after it ends; they indicate uteroplacental insufficiency and require intrauterine resuscitation.

Intussusception

Telescoping of proximal bowel into distal bowel in infants, causing colicky pain, drawing up of the legs, and red currant jelly stool; air enema is diagnostic and therapeutic.

Inulin clearance

The reference method for measuring glomerular filtration rate, because inulin is freely filtered and neither secreted nor reabsorbed by the renal tubules.

Herd immunity threshold

The proportion of a population that must be immune to interrupt transmission, calculated as 1 minus 1 divided by the basic reproduction number R0.

Delirium

Acute fluctuating disturbance of attention and awareness, often caused by infection, medications, or metabolic derangement; it is a medical emergency requiring identification of the cause.

Informed consent

Valid authorization for a procedure requiring patient capacity, adequate disclosure of risks, benefits, and alternatives, comprehension of that information, and voluntary choice.

Dix-Hallpike test

Positioning maneuver that provokes vertigo and nystagmus in benign paroxysmal positional vertigo; a positive test is followed by the Epley repositioning maneuver.

Local anesthetic systemic toxicity

Perioral numbness, seizures, and cardiac arrest after local anesthetic injection; treated with airway support and intravenous 20% lipid emulsion in addition to standard resuscitation.

Hernia anatomy

Indirect inguinal hernias lie lateral to the inferior epigastric vessels and are common in young males; direct hernias lie medial and are common in older men.

Kussmaul breathing

Deep rapid respirations seen in severe metabolic acidosis such as diabetic ketoacidosis; the respiratory compensation lowers arterial carbon dioxide.

Horner syndrome

Interruption of the sympathetic pathway causing ipsilateral ptosis, miosis, and anhidrosis; a Pancoast tumor of the lung apex is a classic cause.