Miscellaneous Flashcards
CKD and parathyroid
CKD leads to 2 things: phosphate retention and lower 1,25 dihydroxyD, which both lead to increased PTH synthesis.
1) lower 1,25 dihydroxyD (reduced renal conversion of 25-D to 1,25) leads to lower intestinal calcium absorption which leads to low serum calcium which leads to increased PTH synthesis and secondary hyperparathyroidism
2) phosphate retention leads to high serum phosphorus which leads to low serum calcium which increases PTH synthesis and secondary hyperparathyroidism
Secondary hyperparathyroidism has high PTH, low/low normal Ca, and low 1,25 D (despite adequate 25D stores). Over time, this can lead to autonomous PTH secretion unresponsive to rising calcium levels, resulting in high calcium levels and very high PTH levels. This is teriatry hyperpara, which can be associated with metabolic bone disease with bone pain and elevated bone specific alkaline phosphatase (high bone turnover)
Indications for parathyroidectomy in tertiary hyperpara:
- persistently elevated calcium (over 10.5), phosphorous or PTH (over 800)
- soft tissue calcs or calciphylaxis (vascular calcs with skin necrosis)
- intractable bone pain or pruritus
Restless legs Syndrome
Diagnostic criteria
- Urge to move the legs AND
- Unpleasant sensations in the legs or other body parts (arms) that begins/worsens during inactivity (lying down, sitting)
- Unpleasant sensations in the legs that
- are relieved by movement (walking, stretching)
- worsen or occur only in the evening/night
- symptoms not explained by another disorder.
Secondary causes
- Iron deficiency anemia
- uremia (ESRD, CKD)
- diabetes
- MS, Parkinson’s
- Pregnancy
- Drugs (antidepressants, metoclopramide)
Treatment
- Mild/intermittent symptoms
- supplement iron when serum ferritin is less than 75
- use supportive measures (leg massage, heating pads, exercise
- avoid aggravating factors (sleep deprivation, meds, alcohol, nicotine, caffeine)
- Persistent/moderate to severe symptoms
- first line - dopamine agonists (pramipexole or ropinirole)
- alternate - alpha 2 delta calcium channel ligands (gabapentin enacarbil)
levodopa causes paradoxically worsening.
Drug induced lupus
Causes multisystem involvement and clinical findings can include fever, malaise, myalgia, arthralgia/arthritis, serositis (pleuritis, pericarditis), and/or hepatomegaly/splenomegaly. Diagnosis is made by history of one or more offending drugs and a positive test for ANA or anti-histone antibodies.
Common drugs linked to it:
- procainamide
- hydralazine (up to 5-10% of patients)
- minocycline
- TNF alpha therapy (etanercept, infliximab)
Treatment is generally symptomatic and discontinuation of offending drug leads to resolution of symptoms within weeks to months.
Duchenne MD
Clinical
- onset at age 2-3
- developmental delay
- proximal muscle weakness usually of hips/thighs (Gower sign, calf pseudohypertrophy)
- dilated cardiomyopathy
- scoliosis
- hyporeflexia of achilles
- waddling gait
diagnosis
- increased serum CK
- genetic testing: dystrophin deletion (confirms)
- muscle biopsy: fibrosis, fat, muscle degeneration (not needed for diagnosis)
Tx
- steroids
Prognosis
- wheelchair dependent by adolescence
- death at age 20-30 from respiratory/heart failure
Affects boys who have defective dystrophin gene on X chromosome. X-linked myopathy.
length time bias vs lead time bias
Length time: In case of prostate cancer (and many chronic diseases), some patients have rapidly progressive disease and some have slowly progressive indolent course. These tend to be asymptomatic for a long time, increasing the chance they will be diagnosed by screening rather than symptoms. These slowly progressive cases also have lower mortality which may give the impression that screening improves disease survival (really, we just identify more benign cases)
Lead time: Occurs when test diagnoses a disease earlier and as a result, the time from diagnosis until death appears prolonged even though there actually is no improvement in survival. Remember, length time identifies more benign cases. Lead time just identifies real cases earlier. Time to death is not prolonged. Just earlier detection.
Observer bias
Occurs when researchers subconsciously or consciously manipulate aspects of a study often due to their own preconceived expectations.
Sampling bias
Study subjects are collected in a non-random process that is more likely to exclude some members of target population than others.
Hawthorne effect
When participants modify their behavior due to their awareness of the fact that they are being studied.
NF-2
Autosomal dominant.
Family history of bilateral deafness, hypopigmented spots. Deafness is from bilateral acoustic neuromas.
Tuberous sclerosis
congenital hypopigmented mcaulae (ash leaf spots), glial proliferation, and several organ hamartomas/cysts.
Sturge-Weber
facial port-wine stain and leptomeningeal angiomatosis
Osler-Rendu-Weber
multiple telangiectasias and vascular lesions in the CNS
autoimmune hepatitis
Causes progressive parenchymal liver damage. Severe cases can progress to cirrhosis and liver failure in 6 months
Most cases occur in young to middle aged women. Autoimmune manifestations such as arthritis, erythema nodosum, thyroiditis, pleurisy, pericarditis, anemia and sicca syndrome
Common findings include elevated AST and ALT, normal/near normal alkaline phosphatase (PBC is the other way around, elevated AP and normal AST/ALT), and normal bilirubin.
Auto-antibodies are common. Most typical are ANA (in a homogeneous staining pattern, hence the term lupoid hepatitis) and anti-smooth muscle antibodies (against actin)
Aspiration PNA vs aspiration pneumonitis
PNA
- infection of lung parenchyma due to aspiration of oral cavity microbes (gram positive cocci, gram neg rods and anaerobes)
- clinical
- elderly patients with dysphagia or gastric dysmotility
- 1-5 days after aspiration event (may be unwitnessed)
- fever, cough, increased sputum, tachypnea
- CXR infiltrate in dependent lung segment (classically RLL)
- Management
- antibiotics (clindamycin or combo beta lactamase inhibitor)
Pneumonitis
- inflammation of lung parenchyma due to aspiration of foreign contents (gastric contents with subsequent acid injury)
- clinical
- patients with depressed level of consciousness (any age group)
- 2-5hrs after aspiration event (typically witnessed)
- range from no symptoms to nonproductive cough, tachypnea, hypoxemia, respiratory distress
- CXR infiltrates (1 or both lower lobes) resolve without antibiotics
- management
- supporitve (no antibiotics)
AKI
Prerenal
- mechanism and associated conditions
- decreased renal perfusion from volume depletion (hypovolemia, hemorrhage) or decreased effective circulating volume (CHF)
- BUN/Cr
- typically above 20
- Fractional excretion of sodium less than 1%
- urine osmolality greater than 500
- bland microscopy
- Management
- fluids (responds to fluid challenge)
ATN
- Mechanism and associated conditions
- tubular injury from renal ischemia, sepsis, low cardiac output or nephrotoxins (aminoglycosides, tenofovir, radiocontast media)
- common in hospitalized patients
- BUN/Cr ratio normal usually (10-15)
- FENa above 2%
- Urine osmolaliy around 300
- Muddy brown casts on microscopy
- Management
- supportive care, treatment of underlying cause and/or removal of offending agent
Postrenal
- mechanism
- obstruction (BPH, renal stones, malignancy)
- BUN/Cr variable
- FENa variable
- Urine osmolality variable
- microscopy bland
- Treatment is relief of obstruction
