Renal/GU Flashcards
Hypernatremia
Na > 145
- usually due to free water loss than sodium gain
Hypernatremia: PE/History
- presents with THIRST due to hypertonicity
- neuro sx: mental status changes, weakness, focal neuro deficits
- “doughy:” skin
Hypernatremic causes “6 D’s”
- Diuresis
- Dehydration
- Diabetes insipidus
- Docs (iatrogenic)
- Diarrhea
- Disease ( sickle cell, kidney,)
Tx: euvolemic hypernatremia
- use hypotonic fluids (e.g. D5W or .45% NaCl)
Tx: hypovolemia hypernatremia
- D5W
- if vital signs unstable, use 0.9% NaCL before correcting free water deficit
Tx: hypervolemia hypernatremia
Use diuretics and D5W to remove excess sodium
Important key facts to keep in mind during correction of hypernatremia
- Chronic hypernatremia (> 36 - 48 hrs) should occur over 48- 72 hrs (<0.5mEq/L/hr to prevent cerebral edema
Hyponatremia
Na < 135mEq/L
- almost due to increased ADH
Hx/PE: hyponatremia
- may be asymptomatic or may present with confusion, lethargy, muscle cramps, hyporeflexia, and nausea
- can progress to seizures coma, or brainstem herniation
Dx: high osmolality hypernatremia
> 295mEq/L
- due to hyperglycemia, hypertonic infusion (e.g mannitol)
Dx: normal osmality hyponatremia
280-295mEq/L
- caused by hypertriglyceridemia, paraproteinemia (pseudohyponatremia)
Dx: low osmolality hyponatremia
< 280 mEq/L
- majoriity of cases
Tx: hypervolemia hyponatremia
- Water resitriction
- consider diuretics
- cortisol replacement w/ adrenal insufficiency
- thyroid replacement w/ hypothyroidism
Tx: euvolemia hyponatremia
water restriction
Tx: hypovolemia hyponatremia
replete volume w/ normal saline
Complication of correcting hyponatremia too quickly?
Central pontine myelinosis
– hyponatremia > 7 hrs should be corrected more than 0.5mEq/L/hr
Hyperkalemia
> 5mEq/L
Spurious hyperkalemia
- hemolysis of blood sample
- delays in sample analysis
- extreme leukocytosis or thrombocytosis
Hyperkalemia 2/2 to decreased excretion
- Renal insufficiency
- Drugs (e.g. spironolactone, triamterene, acodisos, calcineurin)
Hyperkalemia 2/2 to cellular shifts
- Cell lysis
- Tissue injury (rhabdo)
- Insulin deficiency
Drugs (e.g. succinylcholine, digitalis, B-blockers)
Hx/PE: hyperkalemia
- may be asymptomatic
- may present w/ nausea, vomiting, intestinal colic, areflexia, weakness
Dx: hyperkalemia
- confirm w/ repeat blood draw esp in setting of extreme leukocytosia or thrombocytosis
- ECG findings: hyperkalemia
tall peaked T waves, wide QRS,
PR prolongation
loss of P waves
Tx: hyperkalemia
C BIG K DROP
- Give calcium gluconate for cardiac cell membrane stabilization
- Give bicarb and/or insulin + glucose to temp shift K into cells
- B-agonists (e.g. albuterol) to promote cellular reuptake of K
- Kayexalate to remove K from body
Contraindications to kayexylate (esp for tx of hyperkalemia)
- Ileus
- Bowel obstruction
- Ischemic gut
- Pancreatic transpants
Hypokalemia
< 3.5 mEq/L
Etiologies of hypokalemia
- Transcellular shifts (e.g. insulin, B-agonists)
- GI losses (e.g. diarrhea, laxatives, vomiting)
- Renal losses (e.g diuretics, hypomagnesemia)
ECG findings: hypokalemia
T wave flattening, U waves (additional wave after T wave)
ST segment depression leading ot AV block and cardiac arrest
Tx: hypokalemia
- treat underlying disorder
- Oral and/ IVpotassium repletion
- Don’t excess 20mEq/hr
Carbonic anhydrase inhibitors: site of action
e.g acetazolamide
proximal convoluted tubule
Carbonic anhydrase inhibitors (e.g acetazolamide): mechanism of action
inhibit carbonic anhydrase
- increase H+ reabsorption
- block Na+/H+ exchange
Carbonic anhydrase inhibitors (e.g acetazolamide): side effects
Hyperchloremic metabolic acidosis
Sulfa allergy
Osmotic agents (e.g. mannitol, urea): site of action
entire tubule
Osmotic agents: (e.g. mannitol, urea): mechanism of action
increase tubular fluid osmolarit
osmotic agents (e.g mannitol, urea): side effects
pulmonary edema due to CHF and anuria
Furosemide
- loop diuretic
- inhibits Na/K/2Cl in thick ascending limb loop of Henle
- abolishes hypertonicity of medulla preventing concentration of urine
Furosemide: Clinical Use
edematous states (CHF cirrhosis, nephrotic syndrome, pulmonary edema)
- HTN
- Hypercalcemia
Furosemide: Side effecs
OH DANG
- Ototoxicity
- Hypokalemia
- Dehydration
- Allergy (sulfa)
- Nephritis (interstinal)
- Gout
Ethacrynic acid
- loop diuretic
- inhibits Na/K/2Cl in thick ascending limb loop of Henle
- abolishes hypertonicity in medulla
Ethacrynic acid: clinical use
- diuresis in patients allergic to sulfa drugs
Ethacrynic acid: toxicity
- can cause hyperuricemia
* * never use to treat gout
Hydrochlorothiazide
- thiazide diuretic
- inhibits NaCl reabsorption in early distal tubule, reducing diluting capacity of neuron
- decreases Ca excretion
Hypothiazide: clinical use
- HTN
- CHF
- idiopathic hypercalciuria
- nephrogenic insipidus
Hydrochlorothiazide: toxicity
Hyper GLUC
- hypokalemic metabolic alkalosis
- hyponatremia
- hyperglycemia
- hyperlipidemia
- hyperuricemmia
- hypercalcemia
K sparing diuretics
- spironolactone
- triamterene
- amiloride
K sparing diuretics: mechanism
- sprironolactone and epelerone are aldosterone receptor antagonists in the cortical collecting tubules
- triamterene and amiloride block Na channels in CCT
K sparing diuretics: clinical use
Hyperaldosteronism
K depletion
CHF
K sparing toxicity
Hyperkalemia (can lead to arrhythmias)
Endocrine effects w/ spironolactone (e.g. gyncecomastia, antiandrogen effects)
ACE inhibitors
- captopril, enalapril, lisinopril
ACE inhibitors: mechanism
inhibit ACE –> decr. angiotensin II –> decr. GFR by preventing constriction of efferent arterioles
- levels of renin incr due to feedback inhibitor
ACE inhibitors: clinical use
HTN CHF proteinuria diabetic renal disease - prevent heart remodeling due to chronic hypertension
ACE inhibitor toxicity
CATCHH
- Cough
- Angioedema
- Teratogen (fetal renal malformations)
- Creatinine increase (decr. GFR)
- Hyperkalemia
- Hypotension
Renal Tubular Acidosis I
- found in distal tubules
- defect in H+ secretion
- hypokalemia
- pH > 5.3
Etiology of RTA
- hereditary
- cirrhosis
- autoimmune disorders (e.g. SLE, Sjorgen’s syndrome, sickle cells disease)
- Drugs (lithium, amphotericinB
RTA I: Treatment
Replace bicarbonaate
RTA I: Complications
Nephrolithiasis
RTA II
defect in bicarb reabsorption
- low K
initially urine pH is 5.4 , then < 5.3 once serum becomes more acidotic
RTA II: Etiologies
Hereditary (Fanconi's syndrome or cystinosis) Drugs (carbonic anhydrase inhibitor) Multiple myeloma Amyloidosis Heavy metal poisoning Vitamin D deficiency
RTA II: Treatment
Thiazide
Volume depletion to increase absorption
Complications of RTA: II
Rickets, osteomalacia
RTA IV
- in distal tubules
- aldosterone deficiency
- high K
urine pH > 5.3
RTA IV: Etiologies
1st aldosterone deficiency
hyporeninemic hypoaldosteronims
(e.g. kidney disease, ACEis, NSAIDS(
Drugs (e.g amilorde
Treatment of RTA IV
- Furosemide
- Mineralcorticoids +/- glucocorticoid replacement
Acid Base Disorder: pH < 7.4, pCO2 > 40 mmHG
respiratory acidosis
Causes of Respiratory Acidosis
Hypoventilation (retaining CO2)
- Airway obstruction
- Acute lung disease
- Chronic lung disease
- Opioids, narcotics
- Weakening of respiratory muscles
Acid Base Disorder: pH < 7.4, pCO2 < 40 mmHg
Metabolic acidosis
**check anion gap (Na - [K + Cl])
Anion gap metabolic acidosis
MUDPILES
- Methanol
- Uremia
- Diabetic ketoacidosis
- Paraldehyde or pheniform
- Iron tablets or INH
- Lactic acidosis
- Ethylene glycol –> kidney stons
- Salicylates
Normal anion gap acidosis
HARDUP Hyperalimentation Acetazolamide use Renal tubular acidosis Diarrhea Uretocolonic fistula Pancreatic fistula
Acid Base Disorder: pH >7.4, pCO2 < 40 mm Hg
respiratory alkalosis
Causes of respiratory alkalosis
Hyperventilation (e.g. high altitude exposure) Aspiration ingestion (early)
Acid base disorder: pCO2 > 40 mm Hg
Metabolic alkalosis with compensation (hypoventilation)
- Diuretic use
- Vomiting
- Antacid use
- Hyperaldosteronism
Acute Kidney Injury
- defined as abrupt decline in renal fxn
- retention of BUN and Cr
- decreased urine output ( < 500 cc/day)
Prerenal AKI
- cause by hypoperfusion
Common causes of prerenal AKI
- Hypovolemia
- Sepsis
- Drugs (ACEis, NSAIDS)
- Renal artery stenosis
- De
Intrinsic AKI
- injury within nephron unit
Common causes of instrinscicAKI
ischemic or nephrotoxic ATN
Allergic interstitial nephritis
Glomerulonephritis
Post renal AKI
- urinary outflow obstruciton
Common causes of post renal AKI
- prostatic disease
- pelvic tumors
- intratubular causing obstruction
Ddx scrotal swelling
- Hydrocele
- Varicocele
- Epididymitis
- Testicular torsion
Painless causes of scrotal swelling
- Hydrocele
- Varicocele
Hydrocele
- remnant of processus vaginalis
- usually asymptomatic, transilluminates
Varicocele
- dilation of pampiniform venous plexus (“bag of worms”)
- asymptomatic or presents with vague scrotal pain
- affects left testicle more than right
- may disappear in supine position
- DOES NOT TRANSILLUMINATE
Hydrocele: Dx
Lab and radiologic workups rarely indicated
- obtain U/S if concern for inguinal hernia or testicular cancer
Epididymitis
- infection of epididymitis, usually for STDs, prostatitis and/or reflux
- affects > 30 y/o
- presents w/ epididymal tenderness
- enlarged testicles, fever, scrotal thickening, erythema, and pyuria
- pain may decrease with elvevation
Epididymitis: Dx
- UA, culture (pyuria)
- Culture often shows N. gonorrhoeae, E.coli, or Chlamydia
- Doppler ultrasound shows normal to increased flow to testes
Hydrocele: Tx
Typically none unless hernia is present beyond 12-18 mths age
- indicates patent processus vaginalis, which leads to increased risk for inguinal hernia
Varicocele: Dx
Ultrasound
Varicocele: Tx
- if symptomatic or if testes makes < 40% of total volume, maybe treated surgically w/ a varicocelectomy or ligation or through embolization via IR
EpididymitisL Tx
Abx (tetracyclines, fluoroquinolone)
NSAIDS
Scrotal support
Testicular torsion
- twisting of spermatic cord, leading to ischemia and possible testicular torsion
Testicular torsion:
Typically affects those < 30 y.o
- presents with intense, acute-onset scrotal pain that increases or remains the same w/ scrotal elevation
- pain accompanied by N/V and/or dizxiness
- loss of cremestaric reflex
Testicular torsion: dx
Doppler ultrasound shows DECREASED blood flow to testes
- SURGICAL EMERGENCY
Testicular torsion: tx
attempt manual detorsion
- immediate surgery to salvage testis (testis is often unsalvageable after 6 hrs of ischemia)
- orchiopexy of both testes to prevent future torsion
BPH
- enlargement of prostate that is normal part of aginge
> 80% of men by 80 - can result in urinary retension, recurrent UTIs, bladder and renal calculi, hydronephrosis and kidney damange
BPH: Hx
Obstructive sx: hesitancy, weak stream, urinary retenton
Irritative sx: nocturi, daytime frequency, urge incontinence
- DRE shows uniformly enlarged with rubbery texture
BPH: Dx
DRE to screen for masses, if findings are suspicious
Obtain UA and urine culture to r/o infection and hematuria
Measure creatinine levels to r/o obstructive uropathy and renal insufficiency
BPH : Treatment
Alpha-blockers (e.g. terasozin) - relax smooth muscles in prostate and bladder neck
5-alpha reductase inhibitors (e.g. finasteride) - inhibit production of DHT
- TURP or open prostatectomy is appropriate for patients
Renal Cell Carcinoma
- adenocarcinoma from tubular epithelial cells ( 80-90% malignant tumors of kidney)
- tumors can spread along renal vein to IVC
- can metastasize to lung and bone
Risk factors for RCC
- Male gender
- Smoking
- Obesity
- Acquired cystic kidney disease in ESRD
- von Hippel Lindau disease
RCC: Hx
- presenting signs: hematuria, flank pain, and palpable mass
- left sided varicocele often seen due to blockage of gonadal vein into left renal vein then into IVC
- anemia is common but may see polycythemia
DDx for hematuria
I PEE RBCS Infection (UTI) Polycystic kidney disease Exercise External trauma Renal glomerular disease Benign prostatic hyperplasia Cancer Stones
RCC: Dx
Ultrasound and/or CT to characterie renal mass as complex cysts or solid tumor
RCC: Treatment
Surgical resection may be curative in localized disease
Response rate from radiation or chemotherapy are only 15-30%
Sx of ARF
- fatigue, nausea and vomiting, anorexia, SOB, menal status changes
Signs of ARF
- increased BUN and Cr
- metabolic acidosis
- hyperkalemia
- tachypnea (due to acidosis and hypervolemia)
- hypervolemia (b/l rales on exam, JVD, and dilutional hyponatremia)
Three broad categories of renal failure
- Prerenal
- Renal/intrarenal
- Post renal
Prerenal failure
- inadequate perfusion to kidney (which is normal)
Common cause of prerenal failure
- HYPOTENSION - (SBP < 90 mm Hg) from sepsis, anaphylaxis, bleeding
- HYPOVOLEMIA - diuretics, burns, pancreatitis
- Renal artery stenosis
Dx for prerenal failure
- Urinanalysis
- Urine sodium
- Fractional excretion of Na
- Urine osmolality
Prerenal failure (in terms of Una and FeNa)
low Una < 20
low FeNa < 1%
Sx of hypovolemia
- tachycardia, weak pulse, decreased fontanelle
Postrenal failure
- urine is blocked from excreting at some point beyond the kidneys (ureters, prostate, urethra)
Low urine osmolality in healthy persion (no renal issues)
- can be sign of hypervolemia (fluid overload0