General Medicine

·         Low Volume states generally presents with Metabolic Alkalosis…But 3 Exceptions:  Low volume states that present with METABOLIC ACIDOSIS

1.  Diarrhea → loss of HCO₃-

2.  DKA → ↑i ketones

3.  RTA II – loss of HCO₃-

·         Causes of HIGH ANION GAP ACIDOSIS:

mnemonic: C MUDPILES

Cyanide

Methanol

Uremia

Diabetic ketoacidosis

Paraldehyde

Isoniazid, Iron

Lactic acidosis

Ethylene glycol, Ethanol

Salicylates, Starvation

• Causes of NON-ANION GAP ACIDOSIS (hyperchloremic):

mnemonic: USED CARP

Ureteroenterostomy

Spironolactone

Expansion acidosis

Diarrhea

Carbonic anhydrase inhibitors, Cyclosporine

Amiloride

Renal tubular acidosis

Pancreatic fistula, Pentamidine

·         ACTIVITIES OF DAILY LIVING (ADLs):

mnemonic: DEATH

Dressing

Eating

Ambulating

Toileting

Hygiene

• INSTRUMENTAL ACTIVITIES OF DAILY LIVING (IADLs):

mnemonic: SHAFT

Shopping

Housekeeping

Accounting

Food preparation

Transportation

·         The amplitude of the pulse is described on a scale of 0 to 4: 4 = Bounding 3 = Full and increased 2 = Expected (i.e., like the pulse of a 25-year-old) 1 = Diminished and barely palpable 0 = Absent or nonpalpable

·         A mnemonic to remember the causes of shock is SHOCK: Sepsis, Hypovolemia, Other (i.e., Addison’s disease), CNS (neurogenic), and Kardiac causes.

·         A sprain is an injury to a ligament and may be classified as being:

First-degree = Microscopic tears and minimal swelling

Second-degree = Partial disruption, significant swelling, and difficulty bearing weight

Third-degree = Complete disruption, ecchymosis, swelling, and inability to bear weight

·         The palmar surfaces of the fingers are most sensitive to texture, size, position, consistency, crepitus, fluid, and masses. This is why the palm is used for light (1 cm) and deep (4 cm) palpation. The ulnar surface of the hand is best for vibration and the radial surface of the hand is best to determine temperature.

·         The severity of edema is characterized by a grading system, which is as follows:

1+: Slight pitting edema (2 mm deep) with no distortion upon release of finger

2+: A 4-mm-deep pit whose detectable distortion disappears in 10–15 s

3+: A 6-mm-deep pit that lasts more than 1 min upon release of finger

4+: An 8-mm-deep pit that lasts 2–5 min upon release of finger

·         Fifty percent of Chinese and Japanese lack aldehyde dehydrogenase (ALDH) and develop facial flushing and erythema after ingestion of alcohol.

·          

·         TREATMENT FOR PERIODIC PARALYSIS:

Acetazolamide, a carbonic anhydrase inhibitor, is effective in some patients with each form of periodic paralysis. Its effect on the prevention of attacks of hypokalemic periodic paralysis, which is usually provoked by measures that lower the plasma potassium level, is particularly dramatic.

Another carbonic anhydrase inhibitor, dichlorphenamide, may be more effective than acetazolamide in preventing the attacks and reducing interattack weakness.

Patients who are intolerant of carbonic anhydrase inhibitors may benefit from potassium-sparing diuretics such as spironolactone and triamterene.

A low-carbohydrate and low-sodium diet is generally recommended for patients with hypokalemic periodic paralysis.

Inhalation of albuterol, a beta-adrenergic agonist, may prevent the attack in some patients with hyperkalemic periodic paralysis.

Ingestion of a high-carbohydrate, low-potassium diet also may alleviate the attacks.

·         Lack of absorption of vitamin D from the intestinal tract leads to rickets in children and osteomalacia in adults. In children with rickets, neurologic sequelae include head shaking, nystagmus, and increased irritability that may evolve into tetany with a sufficient fall in serum calcium concentrations.

Malabsorption of folate in infants leads to mental retardation, seizures, and athetotic movements, whereas in adults, polyneuropathy and depression are the primary complications.

Pyridoxine deficiency leads to seizures in infants, but a sensory polyneuropathy in adults.

·         Nicotinic acid deficiency results in pellagra, whose major and often sole manifestation is psychiatric disturbance, sometimes mimicking Korsakoff's psychosis.

·         Frostnip is a superficial freeze injury that causes no tissue loss. Patients complain of some discomfort and the involved area is pale; rewarming quickly reverses the symptoms. First-degree frostbite is characterized by partial skin freezing, erythema, edema, no blisters, and desquamation several days later. Second-degree frostbite is characterized by full-thickness skin freezing, erythema, edema, and the presence of clear blisters. Patients complain of throbbing and numbness. Third-degree frostbite injuries are characterized by damage that extends into the subdermal plexis. The skin is blue or gray and there are hemorrhagic blisters. Patients complain of burning, shooting pains, and the feeling that the involved area feels like “a block of wood.” Prognosis is poor. Fourth-degree frostbite injuries extend into the subcutaneous tissue, muscle, and bone. There is typically no edema and the skin is mottled and cyanotic; eventually these injuries form a mummified eschar.

·         Heat exhaustion is associated with temperatures of 99.5° to 102.2° F (37.5° to 39° C); heatstroke is associated with temperatures in excess of 105° F (40.5° C).  Patients with heat exhaustion can have mild confusion, and patients with heatstroke do not have neurologic impairment. Dehydration with tachycardia, low blood pressure as determined orthostatically, and hemoconcentration can occur in either disorder. Two potential acid-base abnormalities in heatstroke are early respiratory alkalosis (associated with tachypnea) and late-occurring metabolic acidosis, resulting from an accumulation of lactic acid. Pure respiratory acidosis would not be expected, especially in a patient with normal mental status and a normal state of alertness. Heatstroke is associated with several renal abnormalities, including hematuria, myoglobinuria, proteinuria, and casts. Hemoglobinuria, a manifestation of lysis of red cells, would not be expected as a result of heatstroke or heat exhaustion. However, it could result from the repetitive impact of this patient's feet on the road during the marathon: so-called march hemoglobinuria. Thrombocytopenia in this setting is ominous because it indicates the presence of disseminated intravascular coagulopathy (DIC), which is more common in exertional than in classic heatstroke. DIC would not be expected to be present with heat exhaustion. DIC is just one of many manifestations of organ dysfunction associated with heatstroke. The list includes acute respiratory distress syndrome, liver function abnormalities, renal failure with active sediment, and severe electrolyte derangements.

·         Malignant hyperthermia of anesthesia usually develops during the initial stages of surgery, but it can develop several hours later. Although external cooling plays a role, the cornerstone of therapy is I.V. dantrolene sodium. Dantrolene is a muscle relaxant; it decreases the heat generated by involuntary muscle contractions.

·         A capitation system provides physicians with a fixed payment per patient per year. This has the potential to encourage physicians to take on more patients but to provide patients with fewer services because the physician is liable for expenses. A fixed salary system encourages physicians to take on fewer patients. A fee-forservice system encourages physicians to provide more services. Out-of-pocket services not covered by insurers are available only to patients with adequate means to receive the service.

·         A receiver operating characteristic curve plots sensitivity on the y-axis and (1 – specificity) on the x-axis. Each point on the curve represents a cutoff point of sensitivity and 1 – specificity. The area under the curve can be used as a quantitative measure of the information content of a test. Values range from 0.5 (a 45° line) representing no diagnostic information to 1.0 for a perfect test.

·         Generally, diagnostic tests are most useful in patients with a medium pretest probability (25–75%) of having a disease. For example, in a patient with a low pretest probability of disease, a positive test can be misleading in that the patient’s posttest probability of disease is still low. The same applies for a patient with a high pretest probability of disease with a negative test: the negative test usually does not rule out disease.

·         Aspirin does not provide primary prevention for myocardial infarction for women with coronary heart disease, but it does provide primary prevention for ischemic stroke and is therefore a useful drug for women at risk for atherosclerotic disease.

·         Grapefruit juice inhibits CYP3A4 in the liver, particularly at high doses. This can cause decreased drug elimination via hepatic metabolism and increase potential drug toxicities. Atorvastatin is metabolized via this pathway. Drugs that may enhance atorvastatin toxicity via this mechanism include phenytoin, ritonavir, clarithromycin, and azole antifungals. Aspirin is cleared via renal mechanisms. Prevacid can cause impaired absorption of other drugs via its effect on gastric pH. Sildenafil is a phosphodiesterase inhibitor that may enhance the effect of nitrate medications and cause hypotension.

·         Except for agent VX, all the organophosphates are liquid at standard room temperature and pressure and are highly volatile, with the onset of symptoms occurring within minutes to hours after exposure. VX is an oily liquid with a low vapor pressure; therefore, it does not acutely cause symptoms. However, it is an environmental hazard because it can persist in the environment for a longer period.

·         Sulfur mustard was the first weaponized chemical and was first used in World War I.

·         Predicted increases in life expectancy are average numbers that apply to populations, not individuals. Because we often do not understand the true nature of risk of disease, screening and lifestyle interventions usually benefit a small proportion of the total population. For screening tests, false positives may also increase the risk of diagnostic tests. While Pap smears increase life expectancy overall by only 2–3 months, for the individual at risk of cervical cancer, Pap smear screening may add many years to life. The average life expectancy increases resulting from mammography (1 month), PSA (2 weeks), or exercise (1–2 years) are less than from quitting smoking (3–5 years).

·         Revised Cardiac Risk Index (RCRI): high-risk surgery, ischemic heart disease, congestive heart failure, cerebrovascular disease, diabetes mellitus, and renal insufficiency

It’s used for for perioperative cardiac events (including pulmonary edema, myocardial infarction, and heart block)

·         A simple way to think of the differences between nondeclarative and declarative memory is to consider the difference between “knowing how” (nondeclarative) and “knowing who or what” (declarative). Nondeclarative memory loss refers to loss of skills, habits, or learned behaviors that can be expressed without an awareness of what was learned. Procedural memory is a type of nondeclarative memory and may involve motor, perceptual, or cognitive processes. Examples of nondeclarative procedural memory include remembering how to tie one’s shoes (motor), responding to the tea kettle whistling on the stove (perceptual), or increasing ability to complete a puzzle (cognitive). Nondeclarative memory involves several brain areas, including the amygdala, basal ganglia, cerebellum, and sensory cortex. Declarative memory refers to the conscious memory for facts and events and is divided into two categories: semantic memory and episodic memory. Semantic memory refers to general knowledge about the world without specifically recalling how or when the information was learned. An example of semantic memory is the recollection that a wristwatch is an instrument for keeping time. Vocabulary and the knowledge of associations between verbal concepts comprise a large portion of semantic memory. Episodic memory allows one to recall specific personal experiences. Examples of episodic memory include ability to recall the birthday of a spouse, to recognize a photo from one’s wedding, or recall the events at one’s high school graduation. The areas of the brain involved in declarative memory include the hippocampus, entorhinal cortex, mamillary bodies, and thalamus.

·         Drugs can trigger inflammatory mediators (histamine, leukotrienes, etc.) directly; i.e., the pharmacoimmune concept. These “anaphylactoid” responses are not IgE-mediated. NSAIDS, aspirin, and radiocontrast media are frequent causes of pharmacologically mediated anaphylactoid reactions. Given that this is an investigational drug, it is improbable that patients in this study have taken this drug before. T cell clones have been obtained after pharmacologically mediated anaphylactoid reactions, with a majority being CD4+. A constitutively IgE receptor would not manifest solely after drug exposure.

·         Nystagmus is a unique feature of ketamine and phencyclidine overdose.

·         Resting energy expenditure can be calculated and is 900 + 10w (where w = weight) in males and 700 + 7w in females. This calculation is then modified for physical activity level. The main determinant of resting energy expenditure is lean body mass.

·         High doses of vitamin E (>800 mg/d) may reduce platelet aggregation and interfere with vitamin K metabolism. Doses >400 mg/d may increase mortality from any cause. Vitamin E excess is not related to increased risk of venous thrombosis. Peripheral neuropathy and a pigmented retinopathy may be seen in vitamin E deficiency.

·         Regulation of virtually every endocrine system is disturbed in patients with anorexia nervosa (AN). Hypothalamic amenorrhea reflects diminished production of GnRH. Serum leptin levels are reduced due to decreased mass of adipose tissue, and this is thought to be the mediator of the other neuroendocrine abnormalities associated with AN. Thyroid function tests resemble the pattern seen in euthyroid sick syndrome (low-normal or depressed TSH and T4, depressed T3, increased reverse T3). Serum cortisol and 24-h urine free cortisol are generally elevated without the expected clinical consequences of hypercortisolism.