Medical Workups Flashcards
QTc Prolongation
Characteristics: The QT Interval in the cardiac cycle represents depolarization (contraction) and repolarization (relaxation) of ventricles. The QTC is the corrected interval time accounting for variations in heart rate. Normal for females is <460msec and <450msec in males. Prolongation can lead to arrythmias, torsades de pointes (TdP), and sudden death. QTc above 500mex is significant risk factor for TdP.
Offending Meds: Typical antipsychotics (esp. thioridazine, chlorpromazine, and IV haloperidol); ziprasidone (though lower rate than typicals); high-dose citalopram (>40mg); amitriptyline; maprotiline; methadone; most psychotropics in overdose
Mechanism: TCAs: blockage of sodium and calcium channels; SSRI/antipsychotics: blockage of potassium channels
General Management: a) Identify risk factors; b) get baseline electrolyes and EKG; c) monitor frequently.
Low Risk Antipsychotics: aripiprazole, asenapine, lurasidone, olanzapine, quetiapine
Low Risk Antidepressants: all are good except citalopram at >40mg; sertraline studied in cardiac patients.
Abnormal Involuntary Movement Scale (AIMS)
- Ask about CURRENT condition of teeth and if they have any observed movements that interfere with activities.
- Patient sits with hands on knees, feet flat. Observe entire body for movements.
- Patient sits with hands unsupported. Observe hands.
- Patient opens mouth. Observe tongue at rest. Repeat.
- Patient protrudes tongue. Observe any abnormalities of tongue movements. Repeat.
- Patient taps fingers on each hand for 15-20s. Observe facial/jaw and leg movements (activated movements).
- Flex arms for cogwheeling.
- Ask patient to stand. Observe trunk and hips.
- Patient extends arms, palms down. Observe trunk, legs, and jaw (activated movements).
- Patient walks a few paces, turns, and returns. Observe gait and hands (activated movements).
Serotonin Syndrome
SHIVERS
S hivering H yperreflexia (and Myoclonus) I ncreased Temperature (Hyperthermia) V ital Signs (Tachycardia and Labile BP) E ncephalopathy (Agitation/Mental Status Changes) R estlessness S weating
Stevens-Johnson Syndrome Identification
Systemic Symptoms: Stevens-Johnson Syndrome is really part of a systemic hypersensitivity reaction. Fever and flu-like symptoms occur first, then a rash appears which progresses rapidly.
Mucosal Involvement: The mucosal involvement often begins with painful, burning sensations of the lips, conjunctivae, nose, and genitalia.
Facial Involvement: The rash involves the face, or the face is swollen.
Rash Characteristics: The rash is typically dark red in color, irregularly shaped, expands, becomes confluent (the different areas of rash are coming together), and spreads to the other areas. The rash may include red or purple spots in the skin or mucous membranes (purpura).
Pain and Peeling Off: There are blisters or the skin is peeling off in any area of the rash, including on the palms and soles. If spontaneous detachment of the epidermis is not seen, put lateral pressure with a finger on a red area of the rash. If the epidermis separates, this is called a positive Nikolsky sign. A red, sometimes oozing dermis may be exposed.
Lymph Glands: Lymph glands in the neck, axilla, and groin are enlarged.
Laboratory Tests: WBC count and hepatic enzymes (AST and ALT) may be elevated. There may be microscopic hematuria.
DRESS Syndrome
DRUG REACTION WITH EOSINOPHILIA AND SYSTEMIC SYMPTOMS
- Begins as a rash that spreads over the body
- Follows with swollen lymph nodes and fever
- Followed by end-organ damage: live, heart, pancreas, or kidneys
Liver Function Tests (General)
Enzymes whose elevation indicates generalized damage to liver cells
* aspartate aminotransferase (AST)
* alanine aminotransferase (ALT)
(previously called transaminases)
Enzymes whose elevations indicates cholestasis (blockage of bile transport and excretion)
* alkaline phosphatase (ALP) * gamma-glutamyltransferase (GGT)
Tests of Liver Metabolism
* total bilirubin
Tests of Liver Synthetic Function
* serum albumin * prothrombin time
AST and ALT Pearls
ALT is found in high concentration in liver cells and in very low concentrations in other tissues. On the other hand, AST is found in many other tissues including muscle, kidney, and brain. This is why ALT is a more specific marker for liver injury (Mnemonic: L is more specific for Liver).
Increases of AST and ALT of 5x normal is still considered a “mild” elevation and are NOT good indicators of the severity of liver damage (even in cirrhosis the levels may be low) (Giannini et al., 2005).
- Mild elevation = up to 5 times the upper limit of normal - Moderate elevation = between 5 to 10 times the upper limit of normal - Marked elevation = more than 10 times the upper limit of normal
Even though alcoholic liver disease is a common cause of injury to the liver, in this condition AST/ ALT levels are typically less than 400 IU/L.
- We can use as a rule of thumb that levels greater than 1000 IU/mL are almost never due to alcoholic liver disease alone.
In most forms of chronic liver disease, including drug-induced liver injury, ALT is more elevated than AST. BUT – in alcoholic liver disease, AST is greater than ALT (because of mitochondrial damage)
AST/ALT Ratio Pearls
- An AST/ALT ratio of greater than two is suggestive of alcoholic liver disease.
- If the AST/ ALT ratio is even greater, e.g., more than three, this is even more strongly suggestive of alcoholic liver disease.
- A ratio of AST/ALT greater than five, especially with ALT either normal or only slightly elevated, usually indicates muscle damage.
Drug-Induced Hepatocellular Injury
DILI
- General: ALT 3x AND ALP 2x
- Hy’s Law:
- normal liver enzymes at baseline
- AST or ALT rises to 3x AND
- Bilirubin is 2x AND
- ALP is normal
- Cholestatic Injury of Medications:
- ALP rises to 3x normal AND
- ALT and AST are both normal
- R Value = (ALT/high normal ALT) / (ALP/high normal ALP)
- Hepatocellular Injury is: ALT 3x AND R>5
- Cholestatic Injury is: ALP 2x normal AND R<2
- Mixed is: ALT 3x, AP 2x, AND 5>R>2
