Pathology Flashcards
Underfill Edema (Pitting)
Def: Edema with a low EABV
Etiology: heart failure, altered starling’s forces (decreased albumin, increased porosity), change in volume/capacitance ratio (pregnancy, liver failure, drugs)
Physiology: Low EABV stimulated RAAS, causing salt and water retention
Overfill Edema (Pitting)
Def: Edema with a high EABV
Etiology: Renal failure, drugs (NSAIDS)
Physiology: Low GFR causes salt and water retention which increases the EABV, causing edema
Localized Pitting Edema
Def: Edema due to a venous issue
Etiology: DVT, mass, venous insufficiency
Lympadema
Def: Edema due to damage to lymphatic system
non-pitting
myxedema
Def: Edema due to protein accumulation under the skin
What are the mechanisms of hyponatremia?
- Reduced filtration
- Increased PCT reabsorption
- Impaired desalination
- Antidiuresis
- Water intake too high for osmoles
Hyponatremia
Definition: Too mich water in the extracellular compartment fluid compaired to Na+. Serum Na
What is SIADH and what causes it?
- Syndrome of innappropriate ADH: gives hyponatremia
2. Causes: cancer, CNS disorders, drugs, pulmonary infections, post-op, HIV
What is the best indicator of ECF volume contraction?
Chlorine, especially in vomiting
What are the three main categories of hypernatremia?
- Increased sodium (rare): hyperaldosteronemia
- Increased water loss
- Decreased water intake
What are the three common causes of polyuria and polydipsia?
- Primary polydipsia
- Central DI
- Nephrogenic DI
What are the causes of secondary hypertension?
- Renal parenchyma
- Mineral corticosteroids
- Vasoconstrictors
- Anatomical changes
- Metabolic
What are the typical presentations of secondary hypertension?
- Age less than 30 or greater than 55
- Resistant to three or more medications
- Hypertensive urgency or emergency
What are important questions to ask in a polyuria history?
- Is it waking them up at night?
2. Do they drink at night?
Hypertensive emergency
- BP severely high with target organ damage, OR recent accelerated rise with some vascular damage evidence
- Immediate HTN diagnosis
Hypertensive urgency
- Systolic over 210
- OR diastolic over 120
- AND no target organ damage
Target blood pressure for diabetics
Less than 130/80
Target blood pressure for general population
Less than 140/90
Signs of target organ damage in hypertension?
- Renal: proteinuria
- Vascular/eyes: papilloedema
- Heart: signs of failure
Typical causes of secondary hypertension
- Vascular: aortic coarctation, renal artery stenosis
- Drugs: cocaine, steroids, lithium, amphetamines, NSAIDs, licorice
- Endocrine: hyperaldosteronemia, pheochromocytoma, cushings, conns, hypercalcemia, thyroid
- Renal: parenchymal disease, renovascular HTN
What does the presence or absence of a nocturnal dip on 24h ambulatory BP measurements tell us?
Presence: happens in essential HTN
Absence: happens in secondary HTN
What does the presence or absence of a nocturnal dip on 24h ambulatory BP measurements tell us?
Presence: happens in essential HTN
Absence: happens in secondary HTN
Why do elderly tend to develop primarily systolic HTN?
- Less elasticity in vessels, especially aorta- fails to buffer force of systole, leading to higher pressures
How do ACE inhibitors impact kidney function?
- Dilate efferent arterioles, which decreases flow through glomerulus
- This decreases GFR and increases creatinine
- Up to 30 % increase in CR expected
What is a finding on physical exam of renal artery stenosis?
- Renal bruits
Which features favour acute kidney injury?
- Large kidneys
- No broad casts
- No hx of kidney disease, HTN, abnormal urinalysis
What are the symptoms of uremia?
Lethargy, malaise, fatigue
Anorexia, nausea, vomit
Confusion
Myoclonus, seizures, coma
What are the main causes of interstitial nephritis?
- Drugs: NSAIDS, beta lactams
- Infections
- Autoimmune
What are the characteristics of acute interstitial nephritis vs chronic?
Acute: rapid, interstitial infiltrate and ended a
Chronic: slow, interstitial fibrosis and scarring
What is the classic tried of interstitial nephritis presentation?
Fever
Rash
Eosinophilia