Pathology Flashcards
What are 4 pathological states leading to urinary tension?
What is a pathological state leading to urinary incontinene?
Tension
- Anticholinergic medications (ex. atropine, gravol, ipatropium)
- Spinal cord injury
- Diabetics
- Stroke damaging the pontine micturition center
Incontinence
- Stroke damaging the pontine storage center
Define the following:
Urinary Tract Infection
Urethritis
Cystitis
Acending pyelonephritis
Pyelonephritis
Asymptomatic Bacteriuria
UTI = an infection affecting part of the urinary tract
Cystisis = an infection of the bladder
Ascending pyelonephritis = UTI affecting the ureters on the way up to the kidneys
Pyelonephritis = an infection of the kidneys
Asymptomatic Bacteriuria = presence of bacteria in urinary tract in the absence of symptoms
What makes a UTI “complicated” (4)
- Presence of DM
- Pregnancy
- Male
- Immunocompromised
Epidemiology of UTI
- How many million people have a UTI each year globally?
- What % of women have a UTI in a given year?
- What % of women have a UTI over their lifetime
- Sexual activity causes what % of bladder infections in young sexually active women?
- What is the age range with the most frequent UTIs?
- 150 million
- 10%
- 50%
- 75-90%
- 16-35
Why do women have an increased risk of a UTI than men? Why does this risk increase with age?
The shorter urethra makes it more likely for a pathogen to invade.
Post-menopausal loss of estrogen leads to the loss of protective vaginal flora
- What bacteria is the most common cuase of a community-acquired UTI? Second most common?
- What 2 bacteria are more likely to be the culprit of a blood-borne UTI?
- What are 2 types of bacteria that can cause urethritis but not cystitis?
- E. Coli, Staphylococcus Saprophyticus
- Staphylococcus Aureus, Salmonella
- Chlamydia trachomatis, Mycoplasma genitalium
What are the gram negative bacteria that can cause a UTI? Gram positive?
What factors increase your risk of developing a UTI? (11)
- Urinary catheter (Foley)
- Sexual intercourse
- Divers using condom catheters or external catching devices
- Female gender
- Diabetes (inhibition of neutrophils)
- Obesity
- Family history
- Lack of circumcision
- Impaired bladder emptying
- Distortion of veiscoureteral junction either from a past infection or a congenital malformation
- Chronic prostatitis
What 5 organisms are associated with a UTI in the context of a catheter?
- E. Coli
- Klebsiella
- Pseudomonas
- Candida albicans
- Enterococcus
What is a vesicoureteral reflux?
The backflow of urine from the bladder and up the ureters
What is the pathogenesis of a UTI?
- Bacteria enter the urethra (usually from the bowel) and travels to the bladder or gains access to the tract via blood or lymph
- Once in the bladder, they create a biofilm by attaching their pili to toll-like receptors. This increases their reistance to our immune system
- Neutrophils attempt to clear the pathogen
What are symptoms of a lower UTI?
- Burning (pain) with urination
- Increased frequeny and urgency of urination
- Difficulty urinating
- Feeling the need to urinate in the absene of a full bladder
- Suprapubic and lower back pain
(6. Blood/pus in urine –> rare)
What are the symptoms of a kidney infection?
- Fever with a high spiking pattern and termination after 3 days of treatment
- Nausea and vomiting
- Flank pain and pain at the costovertebral angle
- Lower UTI symptoms
(5. Blood/pus in the urine –> rare)
What are indications of a UTI in children? Elderly?
Children = fever, poor feeding, vomiting, poor sleeping, fussy, jaundice, new onset urinary incontinence or regression in potty training
Eldelry = delirium, fatigue, fever, chills, and incontinence
What are 6 possible investigations for a UTI?
- Urinalysis = leukocyte esterase and nitrites, (white blood cell casts indicate pyelo)
- Urinalysis with microscopy = >2(m)-10(f) wbc/HPF, rbc
- Urine culture = 100,000 CFU/mL
- Renal U/S = hydro-nephrosis, malformations
- Voiding cystourethrogram = injection of dye with real-time X-ray during urination
- Renal scintigraphy with DMSA = kidney scarring
When is it indicated to do a urinary culture when you are suspicious of a UTI? (5)
- Pregnant females
- All females under 2 years of age
- Uncircumcised males under 1 year of age (but really all males)
- Those presenting with recurrent UTIs
- Elderly with signs of systemic infection and advanced dementia preventing communication
What are complications that can arise from a UTI? (7)
- If during pregnancy, pyelonephritis is more likely to occur
- If during pregnancy, risk of low birth weight or premature infant
- Permanent kidney damage
- Renal papillary necrosis if a kidney infection
- Urethral narrowing in men
- Bacteremia
- Sepsis
What are 5 things you can give to someone with a UTI?
What are 3 types of preventative measures for a UTI?
Treatment:
- Antibiotics
- Methenamine
- Phenazopyridine
- Acetaminophen
- Topical vaginal estrogen
Prevention:
- Drinking lots of fluids
- Good hygiene (wiping from urethra to rectum in women)
- Urinate right after sexual intercourse
How do you treat asymptomatic bacteriuria?
Only treat if pregnant or after a urological procedure.
- Get urine culture
- Treat with amoxicillin or nitrofurantoin
How do you treat cystitis?
Uncomplicated = short course of antibiotics
Complicated = long term of IV antibiotics
How do you treat pyelonephritis?
Antibiotics
How do you treat a perinephric abscess?
- IV antibiotics
- Incision and drainage of the abscess
What are some examples of gram-negative bacteria? What are some examples of gram-positive bacteria? How can you tell which bacteria type has caused a UTI?
Gram negative:
= E. Coli, Klebsiella, proteus, enterobacter, citrobacter, salmonella
Gram positive:
= Enterococcus, staphylococcus saprophyticus, staphylococcus aureus
Gram negative bacteria produce nitrites
What is Pasternacki’s sign?
Pain at the costovertebral angle
What is prostatitis?
What is chronic pelvic pain syndrome?
Acute or chronic infectious and non-infectious abnormalities of the prostate gland leading to enlargement.
When non-infectious, they are referred to as chronic pelvic pain syndrome.
What causes infectious prostatitis? (broadly speaking)
Bacteria
What is the presentation of prostatitis? (acute vs. chronic)
Acute:
- Dysuria
- Increased frequency/urgency of urinating
- Pain in the prostatic pelvic or perineal area
- Fever and chills
- Symptoms of bladder outlet obstruction
Chronic:
- Recurrent episodes of cystitis
- Pain in the prostatic pelvic or perineal area
Other:
- Cloudly/bloody urine
- Abdominal pain
- Pain in penis or testicles
- Painful ejaculation
What is the nephrotic syndrome?
What is the difference between primary and secondary nephrotic syndrome?
What is the nephrotic tetrad seen in this syndrome?
Syndrome = proteinuria, hypoalbuminemia, peripheral edema
Primary = idiopathic, secondary = caused by something we know
Tetrad = the above 3 + hypercholesterolemia
Are adults or children more affected by nephrotic syndrome? Men or women?
What is the most common disease causing nephrotic syndrome in children? adults?
Adults, men
Children = 70-90% from minimal change disease
Adults = 30-40% from membranous glomerulonephritis
What is glomerulonephritis?
Acute inflammation of the kidney, typically due to an immune response
What is minimal change disease? Describe the pathogenesis.
A type of nephrotic syndrome characterized by podocyte effacement and caused by a T-cell mediated process
The loss of negative podocytes allows albumin to move into the Bowman’s capsule
What is membranous glomerulonephritis? Describe the pathogenesis.
What are some secondary causes of it?
A type of nephrotic syndrome characterized by inflammation and spike-like thickening of the glomerular basement membrane.
Subepithalial deposits (antigen-antibody complexes) activate the complement system which creates a membrane attack complex. This complex damages podocytes and mesangial cells and recruits other inflammatory cells. All together, the GBM is damaged and leaky to proteins.
Secondary = infection, malignancy, autoimmune condition, medications
What is focal segmental glomerulosclerosis? Describe the pathogenesis.
What are some secondary causes of it?
A type of nephrotic syndrome characterized by sclerosis affecting only parts of only some glomeruli.
Podocyte damage (idiopathic) allows proteins and lipids to pass by. Some get trapped in the space around the capillaries causing hyalinosis. Over time the trapped molecules develop into sclerosis.
Secondary = sickle cell disease, HIV-nephropathy, heroin-nephropathy, kidney hyperperfusion, increased glomerular capillary pressure
What are 6 outcomes of mass proteinuria and how do they occur?
- Low albumin = loss into urine
- Hypercholesterolemia = liver over-active to replace albumin
- Edema = decreased plasma oncotic pressure from low albumin so that water moves into interstitium
Edema –> decreased CO –> decreased renal blood flow –> decreased GFR –> RAAS –> increased water re-absorption –> worsening edema
- Hypovolemia = decreased plasma oncotic pressure from low albumin so that fluid moves into interstitium
- Increased risk of infection = loss of antibodies into urine
- Hypercoagulable state = greater loss of antithrombin than clotting factors
How does nephrotic syndrome present? (11)
Proteinuria
- Frothy urine
Hypercholesterolemia
- Xanthelasma
- Xanthomata
Hypoalbuminemia
- Tiredness
- Cachexia
- Leukonychia
Peripheral edema
- Periorbital swelling
- Ascites
- Pitting
- Breathlessness (pulmonary edema, pleural effusion)
- Arthralgia
What are diagnostic findings in nephrotic syndrome for:
- Urinalysis
- Blood analysis
- Chest X-ray
- Renal U/S
- elevated (>3.5 g/day) protein, urine Ig, urinary casts
- Low (<2.5g/dL) albumin, high urine protein/creatinine, high cholesterol (LDL/VLDL), LFT showing heightened liver function, possibly low Ca++, possibly high CRP, possibly high glucose (fasting/HbA1)
- Possibly pleural effusion and/or pulmonary edema
- Possibly damage/congenital abnormality?
Fill out the following chart for nephrotic syndrome renal biopsy:
What are possible complications of nephrotic syndrome? (10)
- Thromboembolic disorder from decreased antithrombin
- Infection from lost immunoglobulins (peritonitis > lung > skin > UTI > miningoencephalitis > sepsis)
- Acute kidney failure from hypovolemia
- Pulmonary edema
- Hypothyroidism from lost thyroxine
- Vitamin D deficiency and resulting hypocalcemia
- Microcytic hypochromic anemia from lost iron
- Protein malnutrition and wasting
- Growth retardation from lost hormones
- Cushing’s syndrome from the body trying to compensate with the RAAS
Nephrotic syndrome treatment:
- What is the first line treatment for minimal change disease in children?
- What is another option for treatment (especially frequent relapsers)
- Should steroids be used to treat membranous glomerulonephritis? Focal segmental glomerulosclerosis?
- Steroids (8 week course)
- Alkylating agent (ex. cyclophosphamide)
- Yes but treat underlying disease; Unsure –> inconsistent results
How do you treat the different components/complications in nephrotic syndrome?
What is pre-renal acute kidney injury refer to?
Kidney injury due to decreased blood flow into the kidneys
What are causes of pre-renal acute kidney injury?
- Absolute fluid loss (hemorrhage, vomiting, diarrhea, burns, low intake)
- Relative loss of fluid (distributive shock, CHF)
- Renal artery problems (stenosis, embolus)
- Medications (ACEi, NSAIDs)
- Hypotension
What happens in pre-renal AKI?-
Less blood gets to the kidnesy and the GFR drops. This causes:
- High levels of nitrogen in the blood (azotemia)
- Low urine excretion (oliguria)
- RAAS activation and resultant increase in BP
- Urea reabsorption
Fill in the following lab findings for pre-renal AKI:
How do you treat pre-renal AKI?
- Determine if they are volume high or low
- If high give diuretics; if low give IVF
- Correct the underlying cause
What are 4 main reasons for administering diuretics?
What are 8 other reasons?
- Decrease expanded EC volume (edema)
- Decrease blood pressure
- Increase urinary excretion of excess ions
- Prevent anuria in acute renal failure
Dialysis disequilibrium syndrome, calcium nephrolithiasis, osteoporosis, nephrogenic diabetes insipidus, epilepsy, metabolic alkalosis, altitude sickness, cystic fibrosis
What is hypertension a risk for? (5)
- CAD
- Stroke
- Heart failure
- Renal disease
- Peripheral vascular disease
What is the difference between essential and secondary hypertension?
How do you differentiate between them?
Essential = cause of the BP elevation is unknown (90% of cases)
Secondary = known problem is causing elevated BP
What are the indications for:
- Pre-hypertension
- Hypertension stage I
- Hypertension stage II
- Hypertensive urgency
- Hypertensive emergency
- SBP > 120; DBP > 80
- SBP > 135; DBP > 85
- SBP > 140; DBP > 90
- BP > 180-220/120 with no signs of end organ damage
- BP > 180-220/120 with signs of end organ damage
What are 5 non-modifiable and 9 modifiable risk factors for high blood pressure?
Non-modifiable:
- Family history positive
- Older age
- Male gender
- African American race
- Chronic kidney disease
Modifiable:
- Lack of physical activity
- Unhealthy diet (high in sodium)
- Overweight/obese (strain on CV system)
- Excess alcohol intake
- Sleep apnea
- High cholesterol
- Diabetes
- Smoking/tobacco
- Stress
What things are considered to be “end-organ damage”? (6)
- CHF
- LVH
- Aortic dissection
- Kidney failure
- Pulmonary edema
- Retinal hemorrhage
What are 3 possible causes of primary hypertension?
- Genetics (complex polygenic disorder, RAAS genes)
- Defects in regulation (SNS+, abnormal vascular tone regulators, abnormal ion channels, inappropriate hormone regulation, problems with sensors, abnormal CNS control)
- Insulin resistance and obesity (angiotensinogen released from adipocytes, increased viscosity, insulin activating SNS)
What is part of your work-up in investigating possible causes of secondary hypertension?
- General screening
- Urinalysis and serum creatinine
- Electrolytes (low K+)
- Blood analysis (BUN, glucose, cholesterol, triglycerides)
- Hormone levels (24 hour urine cortisol, TH, PTH, 24 hour urine metanephrines, GH)
- Sleep study
- Bood pressure differences from R to L arm and arm to leg
What are 4 big categories for possible causes of secondary hypertension?
- Exogenous (medications)
- Renal cause (damage, RAAS)
- Mechanical cause
- Endocrine cause
What are 8 possible exogenous causes of secondary hypertension and how do they increase BP?
- Oral contraceptives = estrogen increases angiotensinogen synthesis
- Glucocorticoids = increased SNS
- Cyclosporine
- Erythropoietin = increased blood viscosity
- Sympathomimetic drugs = increased SNS
- NSAIDs = augmentation of renal sodium/water retention
- Ethanol = increased SNS
- Cocaine = increased SNS
- Tyrosine kinase inhibitors
What are 2 major renal causes of secondary hypertension? How do they lead to high blood pressure?
How would you investigate?
- Renal parenchymal disease = damaged nephrons can’t excrete sodium and water –> increased BV –> increased BP
Investigations = low Na+ in urine and high Na+ in serum; possible proteinuria
- Renal arterial stenosis = blocking renal flow and causing RAAS activation
Investigations = abdominal bruit, hypokalemia, elevated aldosterone, imaging
What are 2 mechanical causes of secondary hypertension? How do they lead to high blood pressure?
How would you investigate?
- Coarctation of the aorta = decreased renal flow –> RAAS activation (possibly blunted baroreceptor response to increased BP)
Investigations = BP differences, claudication, fatigue, weak/absent femoral pulse, mid-systolic murmur, imaging
- Obstructive sleep apnea –> fatigue and glucocorticoid release or hypoventilation and hypercapnia
Investigations = sleep study
What are 7 endocrine causes of secondary hypertension?
- Pheochromocytoma
- Primary aldosteronism (ex. Conn Syndrome, bilateral hyperplasia)
- Secondary aldosteronism (ex. renin-secreting tumor, chronic liver disease)
- Glucocorticoid-remediable aldosteronism
- Cushing syndrome
- Thyroid abnormalities
- Acromegaly
Explain how the following endocrine causes lead to secondary hypertension. How would you investigate? How would you treat?
What are possible symptoms of progressive hypertension? (6)
- Sweating
- Headache
- Dizziness
- Epistaxis
- Flushing
- Blurred vision
*Usually asymptomatic until an event or routine exam
What are the complications of hypertension?
What is the pathogenesis of kidney injury as a result of hypertension?
- Vessel walls become thickened with hyaline infiltrate
- Increased hypertension induces smooth muscle hypertrophy and necrosis of capillary walls (fibrinoid necrosis)
- This reduces the vascular supply to the kidney
- Ischemic atrophy of the tubules and glomeruli then occur
What is hypertensive encephalopathy?
Increased intracranial pressure from elevated BP resulting in headache, blurred vision, confusion, somnolence, and coma
What is accelerated-malignant hypertension?
Hypertension resulting in acute damage to retinal vessels and presenting with hemorrhage, exudate, and sometimes papilledema on fundoscopy
What are some non-pharmacologic treatments for hypertension?
- Weight reduction
- Exercise
- Diet (High K+, Ca++, Mg++; low caffeine, salt, alcohol)
- Smoking cessation
- Relaxation therapy
What are 4 classes of drugs used in treating hypertension?
- Diuretics
- Sympatholytics
- Vasodilators
- RAAS blockade
How do diuretics improve hypertension?
What type of hypertensive patient would be given a diuretic?
Thiazides and potassium sparing diuretics promote Na+ excretion and thus water excretion
(Loop diuretics are too potent and short-lived)
Patient = mild to moderate hypertension; normal renal function; salt sensitive people
How do sympatholytics improve hypertension?
What type of hypertensive patient would be given a sympatholytic?
Beta blockers reduce HR and contractility and thus CO which decreases renin
Central alpha-adrenergic agonists reduce SNS signaling to heart, vasculature, and kidney
Systemic alpha-adrenergic blockers relax vascular smooth muscle
Patient = older men shoulduse systemic alpha blockers
How do vasodilators improve hypertension?
Calcium channel blockers reduce cardiac heart contraction and vascular smooth muscle contraction
Hydralizine and minoxidil directly relax vascular smooth muscle of precapillaries
How do RAAS blockade drugs improve hypertension?
What type of hypertensive patient would be given a RAAS blockade?
ACE inhibitors block angiotensin II production which reduces systemic vasoconstriction and water retention
Angiotensin II receptor blockers reduces systemic vasoconstriction and water retention
Direct renin inhibitors reduce systemic vasoconstriction and water retention
Patient = slows down renal failure in diabetic nephropthy
What is renal artery stenosis?
The narrowing of one or both of the renal arteries
What are the 2 most common causes of renal artery stenosis?
- Atherosclerotic renal artery disease (~90%)
Fat, calcium, and immune cells form a crusty rim around inside of artery, usually at beginning
- Renal Fibromuscular Dysplasia (~10%)
Fibrous collagen, connective tissue, and smooth muscle develop abnormally causing a series of bluges, usually at middl to distal end
What are some uncommon but possible causes of renal artery stenosis? (6)
- Vasculitis
- Neurofibromatosis
- Congenital bands
- Extrinsic compression
- Radiation
- Embolus
What is the pathophysiology of renal artery stenosis?
- Narrowing of renal afferent decreases renal blood flow
- JG cells release renin –> RAAS
- RAAS causes systemic and renal constriction
- This maintains GFR at first, but continual constriction leads to systemic hypertension
- Complications such as stroke and heart attack can then occur
What are some complications of renal artery stenosis?
- Renal ischemia –> renal atrophy –> fibrosis
- Stroke from systemic hypertension
- Heart attack from systemic hypertension
What are the signs and symptoms of renal artery stenosis?
Usualy asymptomatic
May have a headache and blurry vision from hypertension
May have flash pulmonary edema brought on by a palliating factor
How do you diagnose renal artery stenosis?
- Renal bruits
- Urinalysis (high serum creatinine, hypokalemia, protein hyaline, casts)
- Imaging (atrophy, malformations)
- Renal arteriography (visualize arteries for the blockage)
- Captopril challenge test (high renin baseline, decreased renin clearance in response to captropril, an ACE inhibitor)
What is the treatment for renal artery stenosis?
- Medications aimed at managing hypertension (diuretics, ACEi, ARBs, vasopressors, sympatholytics)
- Be careful using a RAAS blockade (25-30% rise in creatinine is ok) - Healthy eating and exercise
- Surgery (balloon angioplasty +/- stent, bypass, removal)
- Atherosclerotic medications (aspirin, statins)
What is metabolic acidosis? What are two different types?
MA = a decrease in serum HCO3- causing pH to lower to <7.35
High anionic gap = decreased pH caused by excess H+ that isn’t part of the anion gap
Non-anionic gap = decreased pH due to loss of HCO3- (offset by increased Cl-)
What are causes of high anionic gap metabolic acidosis? (13)
MUDPILES CT / GOLDMARK
- Glycols (ethylene, poly, propylene)
- 5-Oxoproline (chronic acetaminophen ingestion)
- Lactate
- D-lactate (short gut syndrome)
- Methanol
- Aspirin (salicylates)
- Renal failure
- Ketoacidosis
- Uremia (sulphates, phosphates)
- Paraldehyde
- Carbon monoxide
- Cyanide
- Toluene
- Massive rhabdomyolysis
What are causes of non anionic gap metabolic acidosis? (10)
USED CRAP
- Ureterosigmoidostomy
- Small bowel issues
- Extra chloride administration
- Diarrhea
- Carbonic anhydrase inhibitors
- Renal tubular acidosis
- Addison’s disease (hyperkalemia)
- Pancreatic issues
- Parenteral nutrition
- Paraprotein states
How do you determine whether a non-anionic gap metabolic acidosis has a renal etiology or non-renal etiology?
Renal = positive urine anionic gap
Non-renal = negative urine anionic gap
How does the body compensate in metabolic acidosis and what is the result of these compensations? (3)
- Increased absorption of H_ into renal cells –> hyperkalemia
- Increased respiratory rate and depth –> increased minute ventilation, decreased CO2
- Renal compensation –> decreased Na+ and water uptake
What are signs/symptoms of metabolic acidosis? (7)
- Headache
- Altered mental status
- Decreased visual acuity
- Chest pain/palpitations
- Kussmaul respiration
- Nausea/vomiting, abdominal pain, altered appetite, weight gain
- Muscle weakness, bone pain, joint pain
What are serious neurological complications of metabolic acidosis? Cardiac complications?
Neural = coma, seizures
Cardiac = ventricular tachyardia, hypotension
How do you treat a metabolic acidosis?
- IV bicarbonate (50-100 mmol at time –> be careful of ABG readings)
- Dialysis if necessary (kidney failure or OD)
- Treat the underlying cause
What is metabolic alkalosis? What are two different types?
Metabolic alkalosis = an increase in serum HCO3- causing pH to increase to > 7.45
Chloride-responsive MA = chloride lost along with H+ (urine Cl- <10 mEq/L)
Chloride-resistant MA = chloride retained; retention of HCO3- primarily responsible (urine Cl- > 20 mEq/L)
What are causes of chloride-responsive metabolic alkalosis? (6)
- Diarrhea
- Vomiting
- Contraction alklaosis
- Post-hypercapnia
- Cystic Fibrosis
- Excess ingestion of antacids
What are causes of chloride-resistant metabolic alkalosis? (2)
- Hypokalemia
- Excess aldosterone (adrenal tumor, pheochromocytoma, congenital adrenal hyperplasia, Cushing’s)
How does the body compensate in metabolic alkalosis and what is the result of these compensations? (3)
- Increased secretion of H+ from cells –> hypokalemia
- Decreased respiratory rate and depth –> decreased minute venitlation and increased CO2
- Renal compensation –> retention of H+
Possible water gain; possible water loss
What ion is used to assess volume status in metabolic alkalosis?
Chloride
Fill in the fllowing chart for signs and symptoms accompanying the pathophysiological processes in metabolic alkalosis:
What are 4 serious complications of metabolic alkalosis?
- Neurological –> tetany/seizures/decreased mental status
- Decreased coronary blood flow –> arrhythmias
- Hypoventilation –> hypoxemia
- Increased ammonia production –> hepatic encephalopathy
How do you treat metabolic alkalosis? (6)
- Correct the cause
- Correct the deficiency (Cl-, water, K+, etc.)
- Expand ECF volume with normal saline if appropriate
- RAAS blockade
- O2 if necessary
(6. Rarely –> HCl infusion, aetazolamide, oral lysine HCl)
What is respiratory acidosis? What is the differene between acute and chronic?
A failure of the respiratory system leading to a blood pH <7.35
Acute = PaCO2 > 45 with acidemia
Chronic = PaCO2 > 45 with near normal pH and serum HCO3- >30 (renal compensation)
What are causes of acute respiratory acidosis?
Brainstem = stroke, meds/drugs
Neuromuscular = myasthenia gravis, trauma, ALS, G-B syndrome, muscular dystrophy
Airway obstruction = foreign object, asthma
Impaired gas exchange at alveoli:capillary = COPD, pneumonia, pulmonary edema
What are causes of chronic respiratory acidosis? (4)
COPD
Pickwickian syndrome
Interstitial Lung Disease
Thoracic deformities
How does the body compensate for respiratory acidosis? (3)
- Respiratory centers respond to baroreceptors and increase rate and depth of breathing
- Cellular buffering causes a 1 mEq/L HCO3- increase for every 10mmHg increase in PaCO2
3 Renal compensation causes a 3.5 mEq/L HCO3- increase for every 10mmHg increase in PaCO2 (increased bicarb reabsorption and production, renal excretion of carbonic acid)
What are some signs and symptoms of a respiratory acidosis?
- Headache
- Anxiety
- Blurred vision
- Restlessness
- Confusion
How is acute respiratory acidosis treated?
How is chronic respiratory acidosis treated?
Acute = address underlying cause and use artificial ventilation if needed
Chronic = manage underlying condition, give antibiotics/diuretics/bronchodilators/corticosteroids as needed, artificial ventilation if needed
What is respiratory alkalosis? What is the difference between acute and chronic?
Failure of the respiratory system leading to a blood pH of >7.45
Acute = low CO2 and high pH
Chronic = low CO2 and normal pH (renal compensation)
What are some causes for respiratory alkalosis? (9)
Respiratory center
- Normal response to hypoxia (pneumonia, PE, high altitude)
- Abnormal response to hypoxia (panic attack, OD on ASA)
- Brainstem disorders irritating center (tumor)
Iatrogenic increased respiration
- Wrong settings on a mechanical ventilator
Other causes
- Heart disorder
- Thermal insult
- Fever
- Compensation for volume loss in vocal cord paralysis
- Liver disease
How does the body compensate for respiratory alkalosis?
- Respiratory center senses low CO2 levels and responds by slowing down minute ventilation
- Cellular buffering causes 2 mEq/L HCO3- decrease for every 10 mmHg decrease in PaCO2 (proteins in cells excrete H+ into blood –> ex. Hb)
- Renal compensation causes 4-5 mEq/L HCO3- decrease for every 10 mmHg decrase in PaCO2 (release of more HCO3- into blood at the PCT)
What are some signs and symptoms of respiratory alkalosis?
- Dizziness/light-headedness
- Bloating
- Numbness and muscle spasms in hands and feet
- Arm tingling
- Chest discomfort, heart palpitations
- Confusion
- Dry mouth
- SOB
How is respiratory alkalosis treated?
- Treat the underlying cause
- ABG monitoring
- Paper bag breathing
- Pursed lip breathing
What [K+] is considered hyperkalemia? Hypokalemia?
Hyperkalemia = [K+] > 5.5 mmol/L
Hypokalemia = [K+] < 3.5 mmol/L
What are characteristics of an ECG in:
- Hyperkalemia?
- Hypokalemia
Hyperkalemia = peak T waves –> widening QRS complex –> absence o P waves –> sine waves –> asystole, ventricular fibrillation
Hypokalemia = T and U wave (biphasic T), prolonged QT interval, tachycardia
What are 3 complications of hyperkalemia?
What are 7 complications of hypokalemia?
Hyperkalemia:
- Arrhythmias
- Muscle weakness/spasms
- Paralysis
Hypokalemia:
- Arrhythmias
- Weakness/fatigue
- Muscle cramps
- Paralysis
- Rhabdomyolysis
- Polyuria from ADH inhibition
- Interstitial fibrosis
How do you treat hypokalemia?
- Replace potassium (KCl- a good cohice; KHCO3- good if there is acidosis, do NOT give glucose, ensure there is enough Mg)
- Give calcium to eliminate arrhythmias
- Treat the underlying cause
How do you treat hyperkalemia?
- Remove the excess K+
- Renal = Non-K+ sparing diuretic
- GI = resins (binds K+) or induction of diarrhea
- Shift (glucose, beta agonist, bicarbonate)
- Dialysis in extreme cases - Give calcium to eliminate arrhythmias
- Treat the underlying cause
What is shock from a medical standpoint?
A life threatening condition occurring when the body does not get enough blood flow
What are 4 main categories of shock?
- Cardiogenic –> due to heart problems
- Hypovolemic –> due to low total blood volume
- Obstructive –> due to blood flow obstruction outside the heart
- Distributive –> due to abnormal fluid distribution
What are 4 types of distributive shock?
- Anaphylactic
- Septic
- Neurogenic
- Endocrine
What is sepsis?
What is septic shock?
Sepsis = organ injury/damage in response to infection; leads to low BP and abnormal cellular metabolism
Septic shock = worsened sepsis to the point where BP cannot be maintained with IV fluids alone
What are common infections that are known to lead to septic shock? (10)
What percentage of septic shock is due to UTI? RTI? IV? Idiopathic?
- Appendicitis
- Pneumonia
- Bacteremia
- Diverticulitis
- Pyelonephritis
- Meningitis
- Pancreatitis
- Necrotizing fasciitis
- MSRA
- Mesenteric ischemia
UTI = 35%; RTI = 15%, IV = 15%, iatrogenic = 30+%
What is the name for toxins secreted by:
- Gram-positive bacteria
- Gram-negative bacteria
- Exotoxins, enterotoxins
- Endotoxins, lipopolysaccharides
Why does vasodilation occur in septic shock? (3)
- Toxins from bacteria cause direct endothelial injury and thus release of the vasodilator NO
- Toxins from bacteria activate the complement pathway which activates mast cells to release the vasodilator histamine
- Toxins from bacteria activate immune cells (macrophages/neutrophils) which release cytokines leading to vasodilation
Why does septic shock lead to decreased BP?
- Extreme systemic vasodilation
- Immune response causes leaky vessels which decreases intravascular volume
- Immune response causes endothelial damage which leads to clots
In septic shock, what does “low BP” mean?
SBP <90 mmHg
MAP <70 mmHg
SBP decreasing 40 mmHg or more without another cause
What are signs of end-organ dysfunction? (4)
- Kidney failure
- Liver dysfunction
- Changes in mental status
- Elevated serum lactate
What are symptoms of infection in SIRS?
- Fever (>38.0decC) or hypothermia (<36.0degC)
- Hyperventilaion (>20 bpm or PaCO2 <32mmHg)
- WBC < 4,000 cells/mm^3 or >12,000 cells/mm^3
- Tachycardia with HR > 90bpm
How is septic shock treated? (6)
- Give IV fluids (with albumin if large volume)
- Administer a broad spectrum antibiotic
- Administer vasopressors (NE + possibly Epi; angiotensin II in adults)
- Identify source and attempt to control it
- Support any major organ dysfunction (ex. dialysis)
- Get high fever under control
What is acute kidney injury?
What are the 3 categories of AKI?
Acute and sustained decrease in renal function causing either
- Increased serum creatinine by 44.2 umol/L
- Increase in serum creatinine by 20%
3 categories:
Prerenal = decreased renal perfusion; preserved tissue integrity
Renal = injury to the structures of the nephron
Postrenal = obstruction of collecting system
What are t
AKI epidemiology
- How many adults per year have AKI with a serum creatinine > 500 uM?
- How many adults per million have AKI with a serum creatinine > 300 uM?
- How many adults per million have renal replacement therapy a year due to AKI?
- What % of AKI is initially pre-renal?
- What 3 populations have increased risk for post-renal AKI?
- 172 million
- ~550/million
- 131/million
- 75%
- Prostatic disease, single kidneys, intra-abdominal/pelvic cancer
What are 4 categories of causes for pre-renal AKI? Please list examples in each category.
- Absolute fluid loss
- Ex. Major hemorrhage, vomiting, diarrhea, sever burns - Relative fluid loss
- Ex,. Distributive shock, CHF, decompensated liver cirrhosis - Local artery problems
- Ex. Renal artery stenosis, embolus, extrinsic compressionm, vasculitis - Exogenous cause
- Ex. NSAIDs, ACEI or ARBs in context of CHF, RAS, dehydration
What are 6 pathophysiological consequences that occur in pre-renal AKI?
- Azotemia
- Oliguria
- Edema
- Hypernatremia
- Hypertension
- Progression to ischemic acute tubular necrosis
What are 3 categories of causes for post-renal AKI? Please list examples in each category.
- Extrinsic compression
- Ex. Intra-abdominal tumor, prostatic tumor, BPH - Internal blockage
- Ex. Kidney stones, bladder stones, tumor inside the tract - Exogenous cause
- Ex. Obstructed urinary catheter
What are 6 pathophysiological consequences that occur in post-renal AKI?
- Oliguira
- Azotemia
- Hydronephrosis
- Edema from pressure
- Hypernatremia from pressure –> becoming hyponatremia as high pressures damage the lumen epithelium
- Hyperkalemia (on complete obstruction)
What are the 4 types of renal AKI?
- Vascular
- Glomerular
- Interstitial
- Tubular necrosis
What are causes of AKI?
Vascular (2)
Glomerular (3)
Interstitial (5)
Tubular necrosis (3)
- Vascular
- Microangiopathies (pre-eclampsia, DIC, vasculitis, HT), sickle cell disease - Glomerular
- Post-infectious glomerular nephritis, nephrotic syndrome, auto-immune destruction - Interstitial
- Drugs, chronic use of analgesics, DM, pyelonephritis, auto-immune destruction - Tubular necrosis
- Ischemia (pre-renal AKI), exogenous toxins (drugs, poisons), endogenous toxins (rhabdomyolysis, hemolysis, tumor lysis syndrome, oxalate, myeloma)
Describe the pathophysiology of tubular necrosis:
- Something causes necrosis of the tubular epithelium
- Dead epithelial cells slough into the tubule and build up, plugging the tubule
- This increases tubular pressure proximal the plug –> decreased GFR –> oliguria and azotemia
- This decreases tubular pressure distal to the plug –> RAAS –> edema, hypernatremia
- With more and more damage, less re-absorption and secretion occurs –> hyperkalemia, metabolic acidosis
Describe the pathophysiology of glomerulonephritis:
- Antigen-antibody complexes deposit in glomerular tissue
- This activates teh complement system which recruits more immune cells such as macrophages and neutrophils
- Immune cells release lysosomal enzymes which causes inflammation and damage of the podocytes
- Damaged podocytes allow protein tino the urine –> proteinura, hematuria
- Fluid leakage reduces pressure gradient driving filtration of the smaller molecules ane electrolytes and GFR actually goes down –> oliguira, azotemia
- The kidneys try to respond by activating RAAS –> hypertension, hypernatremia, edema
Fill in the following findings for pre-renal, renal, and post-renal AKI:
When is renal biopsy indicated in AKI? (4)
- Unexplained with 2 non-obstructed normal sized kidneys
- AKI in the presence of nephritic syndrome
- Systemic disease associated AKI
- Kidney transplant dysfunction
What is the first line imaging modality in AKI? What is used for F/U?
First line = renal U/S
F/U = MRI and CT (without contrast)
What post void residual value would suggest neurogenic bladder dysfunction?
>50-100mL
What are all the steps taken when managing/treating AKI?
- Prevent cardiovascular collapse/death and call a nephrologist
- Identify the underlying cause and try to treat
- Correct electrolyte imbalance
- Monitor kidney function
(Avoid NSAIDs, iodinated contrasts, some antibiotics)
What 7 groups are at risk for acute tubular necrosis as a post-surgical complication?
- Pre-existing renal impairment
- Hypertension
- Cardiac disease
- Peripheal vascular disease
- DM
- Jaundice
- Advanced age
What 2 drug categories are most frequently associated with drug-induced AIN?
Give 7 other examples:
- NSAIDs
- PPIs
Others =
- Cephalosporins
- Methicillins
- Fluoroquinolones
- Phenytoin
- Allopurinal
- 5-aminosalicylates
- Captopril
What are 4 theories for how drugs cause AIN via immune reactions?
- Drug serves as a hapten –> binds to endogenous protein making it antigenic
- Molecular mimicry
- Drugs become trapped in interstitium
- Drugs form a circulating immune complex which is deposited in the interstitium
What type of immune reaction is drug-induced AIN thought to be?
(2 possible types…cell vs. antibody)
Type I (IGgE) or IV (T cell) hypersensitivity
Cell-mediated immunity
What is a compliation of drug-induced AIN?
Scar tissue that permanently damages renal function
What are 6 presenting symptoms indicative of drug-induced AIN?
What are some other more general symptoms?
On U/S, what happens to echogenicity?
- Sudden impairment of renal function
- Mild proteinuria (not nephrotic)
- Abnormal urinalysis (hematuria, pyuria, leukocyte casts, eosinophils, leukocytes)
- Flank pain
- Normal BP
- No edema
General = malaise, anorexia, nausea, joint pain, skin rash
Echogenicity increases on U/S
How is drug-induced AIN diagnosed?
Must be confirmed with a kidney biopsy
- Dziffuse or patchy inflammatory infiltrates in the deep cortex and outer medulla
- Mostly T-cells, monocytes, and macrophages
- Few plasma cells, eosinophils, neutrophils
- Sparse, non-necrotic granulomas
- Possible tubulitis
- Interstitial edema between tubules
- Normal glomeruli