ABIM 2015 - Nephro Flashcards
GFR is used to assess KIDNEY FUNCTION and SERUM Cr, to ESTIMATE the GFR. What happens to the Cr when the GFR is REDUCED by 50%?
It DOUBLES (so a GFR of 60 that drops to 30 will make a Cr that is 1.0 increase to 2.0)
What is the SERUM Cr expected to do in the setting of NEPHROTIC syndrome?
DECREASE ( due to tubular over secretion) and thus not well correlated with kidney function or GFR estimation
What effect do CIMETIDINE and TMP (TMP-SMX) have on SERUM Cr?
INCREASE it without any change in the GFR
Muscle wasting, Protein malnutrition, Cirrhosis, Poor kidney perfusion, GI BLEED, meds all AFFECT these COMMONLY-used renal laboratory markers WITHOUT any actual changes in KIDNEY FUNCTION?
BUN and Cr
In extremes of HEIGHT and WEIGHT, PREGNANCY, patients who have had AMPUTATIONS, or CIRRHOSIS should have their GFR measured how?
Based of 24 HOUR URINE collection
What test measures the GFR very precisely?
Radionuclide Kidney Clearance Scanning
What GFR estimation do MOST labs use and is the BEST estimation of GFR in CHRONIC KIDNEY DISEASE (CKD)?
MDRD equation and they report HIGH GFR levels as >60 mL/min
How is a PROPER urine sample obtained?
Clean Catch, Mid-stream or via Bladder Catheterization and EXAMINED within 1 HOUR of collection
This measurement of urine is a ratio of the weight of urine to an equal quantity of water and an indication of the kidney’s ability to maximally dilute or concentrate the urine?
SPECIFIC GRAVITY
A specific gravity of urine of 1.005 is? If 1.030?
SG - 1.005 is DILUTE (close to water)
SG - 1.030 is CONCENTRATED “dehydrated’
High protein diets result in consumption of a high “ACID-ash” content and the need for the kidneys to excrete the acid load making the urine more ACIDIC (pH 5.0 - 6.0), conversely, a STRICT VEGETARIAN diet results in a more alkaline urine with a pH of ≥7.0. What infections and condition causes an ALKALINE urine?
Distal RTA, PROTEUS and PSEUDOMONAS
High-alkaline urine (as in vegetarian diets) result in what false-positive component result on a urine DIP STICK?
False HIGH-PROTEIN (albumin) level
When the urine DIP STICK test is NEGATIVE for protein (albumin) but there is suspicion for MULTIPLE MYELOMA, what test can be done on the urine to evaluate for the presence of LIGHT-CHAINS?
SULFOSALICYLIC ACID (SSA)
What is the BEST estimate of GFR in PREGNANT WOMEN, EXTREMES of AGE/WEIGHT, AMPUTEES and CIRRHOSIS?
Cr Clearance
When does glucose spill into the urine and is therefore detected on urine DIP STICK?
When serum glucose >180 mg/dL OR in PROXIMAL RTA
ONE of these THREE (3) substances is detected on the urine DIP STICK when there is DKA, SALICYLATE TOXICITY, ISOPROPYL ALCOHOL POISONING, STARVATION, however, the OTHER TWO (2) are NOT detected (such as in ALCOHOLICS), why?
KETONES (acetoacetate)
Because alcoholics with ketoacidosis make β-hydroxybutyrate which is NOT detectable on urine DIP STICK, neither is acetone (the three ketoacids)
What TWO (2) commonly used drugs can result in FALSE-POSITIVE results for KETONES?
CAPTOPRIL and LEVODOPA
How many RBC’s/hpf are required to result in a POSITIVE urine DIP STICK for BLOOD?
1-3 (detects BOTH free Hb and RBC’s)
What can RIFAMPIN, CHLOROQUINE and MYOGLOBIN and INTRAVASCULAR HEMOLYSIS do to the urine DIP STICK?
Cause FALSE-POSITIVE BLOOD readings
What does Vitamin C (ascorbic acid) do to the urine DIP STICK?
It can cause FALSE-NEGATIVE results for RBC and BILIRUBIN detection
Can the urine DIP STICK be used to confirm MYOGLOBINURIA in patients with RHABDOMYOLYSIS?
NO! (have to use separate urine MYOGLOBIN test)
What cells contain the enzyme LEUKOCYTE ESTERASE and how many of them are needed to have the urine DIP STICK result POSITIVE for this?
LEUKOCYTES, 3/hpf
How are Gm NEG bacteria such as E.coli, Klebsiella, Proteus and Pseudomonas detected on urine DIP STICK?
By the presence of NITRITES (conversion of nitrates by the bacteria)
A UTI with what bacteria can result in FALSE NEGATIVE values on urine DIP STICK for NITRITES?
Gm POS bacteria like ENTEROCOCCUS
What is suggestive of the presence of BOTH urine NITRITES and LEUKOCYTE ESTERASE on urine DIP STICK? What about the ABSENCE of BOTH?
PRESENCE of BOTH - positive for UTI
ABSENCE of BOTH - negative for UTI
What does the presence of CONJUGATED (direct) BILIRUBIN in the urine suggest?
SEVERE LIVER disease or OBSTRUCTIVE JAUNDICE (colors the urine DARK like “coca cola” or “tea”)
Why is UNCONJUGATED bilirubin called “INDIRECT”?
Because it comes from the breakdown of RBC’s by the spleen and is BOUND to ALBUMIN for transport to the liver for conjugation, and note readily soluble in water without breaking the albumin-bilirubin bond, thus called “indirect.”
What drug causes FALSE POSITIVE results for the PRESENCE of BILIRUBIN on the urine DIP STICK?
CHLORPROMAZINE
What does a POSITIVE urine DIP STICK result for UROBILINOGEN mean?
Hemolytic Anemia or Hepatic Necrosis, NOT OBSTRUCTION
How many WBC’s in the urine are suggestive of PYURIA?
> 4 WBC’s/hpf
PYURIA in the urine (>4 WBC’s/hpf) usually suggests a UTI. When the PYURIA is STERILE (negative urine culture), what INFECTION can cause STERILE PYURIA?
TB
Acute Interstitial Nephritis (AIN) - typically caused by ANTIBIOTICS, NSAIDS and PPI’s, ACUTE kidney TRANSPLANT REJECTION and kidney STONES can all cause what type of PYURIA?
STERILE (not associated with UTI)
What drugs can typically cause Acute Interstitial Nephritis (AIN) which presents with some BLOOD and RBC CASTS?
Antibiotics, NSAIDS, PPI’s
The finding of these cells in the urine suggests an ALLERGIC reaction, ATHEROEMBOLIC disease, RPGN, SMALL-VESSEL VASCULITIS, PROSTATE disease or a PARASITIC INFECTION?
EOSINOPHILS
What can cause ISOMORPHIC (same size/shape) RBC’s in the urine?
GU tract TUMOR, STONE or INFECTION
What can cause DYSMORPHIC (varying sizes, shapes) RBC’s in the urine?
pH/Osmolality shifts
When ACANTHOCYTES (oddly/abnormally-shaped RBC’s) are found in the urine, this suggests?
glomeruloNEPHRITIS, SEVERE INTERSTITIAL NEPHRITIS and ACUTE TUBULAR NECROSIS (ATN) - acathocytes and RBC casts
What is the BASIC matrix of ALL urine CASTS (which are formed in the TUBULES and therefore cylindrical)?
Tamm-Horsfall mucoprotein also called HYALINE
What condition can cause HYALINE CASTS (made up of only the Tamm-Horsefall mucoprotein alone) in the urine?
HYPOVOLEMIA causing POOR KIDNEY PERFUSION
What are the TYPICAL CRYSTALS seen in the urine?
CA-OXALATE, CA-PHOSPHATE, URIC ACID, STRUVITE
A NORMAL urine SPECIFIC GRAVITY of 1.010 is related to a NORMAL (ISOSMOTIC) urine OSMOLALITY of?
300 (Same as Serum “isosmolar”)
A LOW urine SPECIFIC GRAVITY of 1.002 (close to water at 1.000) is related to a LOW (MAXIMALLY DILUTED) urine OSMOLALITY of?
50-100 (Maximally Diluted)
A HIGH urine SPECIFIC GRAVITY of 1.030 is related to a HIGH (MAXIMALLY CONCENTRATED) urine OSMOLALITY of?
1200 (Maximally Concentrated)
When there is kidney TUBULAR INJURY, this leads to the deposition of PIGMENTED tubular debris in the Tamm-Horsefall mucoprotein matrix or “HYALINE” forming pigmented-granular casts called what?
MUDDY-BROWN casts
Patients with glomeruloNEPHRITIS will have what type of TUBULAR CASTS?
ERYTHROCYTE (RBC) casts
In patients with tubulointerstitial inflammation of the kidney, including PYELONEPHRITIS, what types of TUBULAR CASTS are found?
LEUKOCYTE (WBC) casts
How is the daily amount of URINE PROTEIN (albumin) excreted measured?
By the urine PROTEIN-CREATININE ratio
- What is considered a NORMAL urine TOTAL protein excretion? 2. What is considered NEPHROTIC-RANGE proteinuria for TOTAL protein?
- NORMAL -
SPOT-TEST: NONE to “TRACE” or “5-20 mg/dL” on DIP STICK (or 30 mg/dL on DIP STICK (or >0.2 mg/mg PROTEIN:Cr ratio)
24-HOUR TEST: >300 mg/24h
- What is considered a NORMAL RANDOM urine PROTEIN:Cr RATIO? 2. NEPHROTIC RANGE?
- 3.5 mg/mg is nephrotic range (random urine PROTEIN:Cr ratio)
To make a DIAGNOSIS of PROTEINURIA, what is REQUIRED?
Collection of TWO (2) abnormal SAMPLES on TWO (2) DIFFERENT DAYS
How should urine be FURTHER tested if proteins found are IMMUNOGLOBULINS?
IMMUNOFIXATION (to determine which immunoglobulins)
What proteins BESIDES the DIP-STICK DETECTED ALBUMIN can be found in URINE and MUST be tested for by using SULFOSALICYLIC ACID (SSA) test?
Kidney-Derived Low Molecular Weight proteins, Immunoglobulins, Light-Chains, Myoglobin, Hb
If additional proteins in a urine SULFOSALICYLIC ACID (SSA) test are found to be Low-Molecular Weight proteins (kidney-derived), where is the associated disease anatomically?
Tubulointerstitial (within the TUBULES)
If the majority of the protein in PROTEINURIA is found to be ALBUMIN, where is the associated disease anatomically?
GLOMERULUS
When must the PROTEIN:Cr RATIO be measured for DM-I and DM-II patients in order to AVOID KIDNEY DISEASE?
DM-I: 5-YEARS after diagnosis
DM-II: AT TIME of DIAGNOSIS
A urine PROTEIN (alb):Cr RATIO of what is considered MICROALBUMINURIA when POSITIVE on 2 of 3 RANDOM samples obtained over 6 MONTHS which suggests HIGH-RISK for kidney and cardiovascular disease?
Urine Alb:Cr ratio of 30 - 300 mg/g (DM, HTN)
What MEDICATION DELAYS progression of KIDNEY DISEASE in patients with DM and MICROALBUMINURIA?
ACE-I and ARB’s
When PROTEINURIA is TRANSIENT (values not repeated on random tests), it is BENIGN and can be seen in what situations?
FEBRILE ILLNESS, RIGOROUS EXERCISE or in YOUNG patients
What is the BENIGN CONDITION called when YOUNG patients (
ORTHOSTATIC PROTEINURIA (BENIGN CONDITION) - obtain a “split urine collection”
What is the SHAPE of Ca-OXALATE crystals in the URINE?
ENVELOPE (but can also see dumbbell/needle and are associated with HYPERCALCIURIA, HYPEROXALURIA, Ca-OXALATE STONES and ETHYLENE-GLYCOL “antifreeze” poisoning)
What is the SHAPE of Ca-PHOSPHATE crystals in the URINE?
PRISM (can also see needle) and are associated with DISTAL RTA, ALKALINE pH >6.5 and TUMOR LYSIS SYNDROME
What is the SHAPE of URIC ACID crystals in the URINE?
RHOMBOID (can also see needle) and are associated with DM, OBESITY, GOUT, TUMOR LYSIS SYNDROME and an ACIDIC pH
What is the SHAPE of Mg-Ammonium-Phosphate “STRUVITE” crystals in the URINE?
COFFIN-LID and are associated with CHRONIC UTI’s with urease-producing bacteria
What is the SHAPE of CYSTINE crystals in the URINE?
HEXAGONAL and are associated with CYSTINURIA
A SPOT ALBUMIN-SPECIFIC DIP-STICK TEST(not 24h) for urine ALBUMIN of what is considered normal?
.
What is the most COMMON cause of HEMATURIA (>3 RBC’s/hpf on urine DIP STICK)?
UTI’s and Kidney STONES
For OLDER patients (>40) AND those with RISK factors, what should be done after a SINGLE episode of HEMATURIA?
FULL evaluation of the UPPER and LOWER GU tract (if
What is GROSS hematuria most COMMONLY associated with?
MALIGNANCY (if RED - urinary tract, if BROWN/TEA-colored - glomeruloNEPHRITIS)
What are the RISK factors for URINARY BLADDER CANCER?
SMOKING, MALE, AGE >40, GROSS HEMATURIA, PELVIC RADIATION, CYCLOPHOSPHAMIDE, Occupational Exposures (benzines, aromatic amines - Fuel Refineries, Rubber, Textile, Dyes)
A MALE SMOKER AGED >40 p/w ISOMORPHIC HEMATURIA (same size and shape RBC’s), what should be done next?
HIGH-RISK: do CYSTOSCOPY and UPPER GU tract IMAGING (CT-urography if GFR ≥60; MR-urography if GFR 30-60 mL/min) as well as CYTOLOGY
A MALE SMOKER AGED >40 p/w DYSMORPHIC HEMATURIA (different size and shape RBC’s) and ACANTHOCYTES, RBC CASTS, PROTEINURIA what should be done next?
Kidney US and Nephrology CONSULT for possible BIOPSY
What GU tract imaging is RECOMMENDED for young patients (
US (CT if very OBESE)
What is a NON-CONTRAST, HELICAL CT-abd/pelv scan used to diagnose when a patient presents with microscopic hematuria ± pain?
NEPHROLITHIASIS
AFTER a NEGATIVE UPPER GU tract evaluation by imaging in a patient with HEMATURIA, what is the PREFERRED method of evaluating the LOWER GU tract?
CYSTOSCOPY
Why is MR-urography for evaluation of the UPPER GU tract contraindicated in patients with a GFR
Because it uses GADOLINIUM contrast (NEPHROGENIC SYSTEMIC FIBROSIS)
What should be done if a patient is found to have HEMATURIA but also has an UNDERLYING bleeding condition or is on ANTICOAGULATION?
EVALUATE as if no underlying bleeding condition or anticoagulation
What is the FIRST imaging study that should be used to image the UPPER GU tract when looking for OBSTRUCTION, CYSTS, MASSES, Kidney Size and Cortical Thickness? Renal Artery Stenosis?
US Doppler US (for renal artery stenosis)
What GFR value is REQUIRED for patients to undergo CT-urography (for evaluation of the UPPER GU tract for hematuria, etc.)?
GFR ≥60 (normal)
When is RADIONUCLIDE Kidney Clearance Scanning done to EXTREMELY ACCURATELY determine the GFR keeping in mind that this test is VERY EXPENSIVE?
Evaluation of PERFUSION/FUNCTION of TRANSPLANTED KIDNEYS and PRIOR to NEPHRECTOMY, ASSESSMENT of functional significance of RENOVASCULAR disease and functional significance of HYDRONEPHROSIS in obstructed patient
What should be done in a patient in whom GLOMERULAR disease is suspected (nephRITIC, nephROTIC syndrome, acute kidney injury of unknown cause and kidney TRANSPLANT dysfunction)?
US or CT-guided BIOPSY!!
BLEEDING condition, ACTIVE GU infection, HYDRONEPHROSIS, ATROPHIC kidneys and UNCONTROLLED HTN are CONTRAINDICATIONS to what TEST for kidney disease?
BIOPSY
What complication, BESIDES PAIN, can COMMONLY be seen after KIDNEY BIOPSY?
HEMATURIA that can result in obstruction (clots) or requiring a transfussion
What is the OSMOLALITY (# of osmoles of substance - compounds, anions, cations, etc. per L of plasma) of PLAMA determined by?
Concentration of SODIUM (a cation “+”) and its ANIONS (-) “Cl, HCO3, etc.” GLUCOSE and BUN
The DIFFERENCE between the MEASURED and CALCULATED plasma osmolality is called what?
SERUM OSMOLAL GAP
What is considered an ELEVATED Serum (plasma) Osmolal GAP and what is it due to?
> 10 mosm/Kg H2O
Due to the presence of UNMEASURED solutes that were not accounted for when subtracted from the CALCULATED osmolality
What is considered NORMAL serum (plasma) osmolality, which is TIGHTLY regulated to maintain a CONSTANT INTRAcellular volume?
275-295 mosm/Kg H2O
What part of the BODY contains OSMORECEPTORS which SENSE changes in SERUM (plasma) osmolality?
HYPOTHALAMUS
What does the HYPOTHALAMUS do when it SENSES >1-2% INCREASE in SERUM (plasma) osmolality?
It triggers the release of ANTI-DIURETIC HORMONE (ADH) or “VASOPRESSIN” by the POSTERIOR PITUITARY, causing the renal COLLECTING DUCTS (last portion of the tubule system of the nephron) to REABSORB WATER and NOT EXCRETE it as it would otherwise)
When does PHYSIOLOGIC release of ANTI-DIURETIC HORMONE (ADH) or “VASOPRESSIN” occur by the POSTERIOR PITUITARY?
During HYPOVOLEMIA
When does does NON-PHYSIOLOGIC release of ANTI-DIURETIC HORMONE (ADH) or “VASOPRESSIN” occur by the POSTERIOR PITUITARY or BY TUMORS?
In the condition known as Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH)
What is it called when the SERUM SODIUM concentration is
HYPONATREMIA (can occur with increased, normal or decreased plasma osmolality)
In patients with HYPERGLOBULINEMIA or SEVERE HYPERLIPIDEMIA (usually visible in test tube), the SODIUM may be
PSEUDO-HYPOnatremia (not a true low sodium, but rather the presence of other solutes or “osmoles” in the serum causing an apparent “dilutional effect” on the amount of SODIUM which did not change, thus would have an INCREASED OSMOLAL GAP because these osmoles were not measured)
The relationship between the CONCENTRATION of SOLUTES (substances dissolved in EXTRAcellular fluid and INTRAcellular fluid) on EITHER SIDE of the CELL MEMBRANES is called what?
TONICITY
This is the most COMMON form of HYPOnatremia and can occur in patients with NORMAL, INCREASED or DECREASED EXTRAcellular FLUID?
HYPOtonic HYPOnatremia
What is the USUAL measured PLASMA OSMOLALITY in a patient with HYPOtonic HYPOnatremia?
LOW (however, it can be NORMAL or INCREASED if BUN, GLUCOSE or an exogenous solute like ALCOHOL is present)
What is HYPERtonic HYPOnatremia caused by?
SIGNIFICANT HYPERGLYCEMIA (elevated GLUCOSE) or exogenously administered solutes like MANNITOL or SUCROSE - because the presence of these EXTRA solutes in the plasma or “extracellular fluid” causes that fluid compartment to have a HIGHER concentration than the INTRAcellular fluid and therefore INTRAcellular fluid diffuses into the EXTRAcellular fluid compartment to equilibrate the concentration thus effectively DILUTING the SODIUM concentration there
HOW does the presence of HYPERGLYCEMIA affect WATER movement across CELL MEMBRANES?
It forces water OUT of the CELLS (lower solute concentration) in order to equilibrate the now higher concentration of solute in the EXTRAcellular fluid
What FLUID compartment is referred to when discussing TONICITY and hypo/hyper NATREMIA?
THE PLASMA or EXTRAcellular FLUID (anything that ends in “emia” is referring to the BLOOD (of which PLASMA is the greatest component)
When is ISOSMOTIC HYPOnatremia seen?
When ≥2 disorders are present simultaneously (ie, when a patient with HYPOnatremia due to SIADH develops HYPERglycemia having a NORMAL plasma osmolality as the INCREASE in osmolality resulting from the INCREASED GLUCOSE counterbalances the initial DECREASED osmolality caused by the SIADH - associated water retention
What is meant by ISOSMOTIC?
When two solutions (EXTRAcellular fluid and INTRAcellular fluid) have same number of solutes - therefore NO MOVEMENT of water (the solvent) exists
What is meant by ISOTONIC?
When a solution has the SAME CONCENTRATION as the blood (serum)
When the OSMOLALITY is increased, what does this MEAN?
It means that the CONCENTRATION of the solution (serum) has INCREASED due to the presence of increased OSMOLES
In the setting of elevated CHOLESTEROL, TRIGLYCERIDES or TOTAL SERUM PROTEIN with concomitant HYPOnatremia, what is the cause of HYPOnatremia?
PSEUDO-HYPOnatremia (caused by the presence of the unmeasured osmoles (lipids, protein) that cause a FLUID SHIFT from the INTRAcellular space to the EXTRAcellular space thus causing a DILUTIONAL effect. These osmoles are unaccounted for when the Plasma Osmolality lab value is measured which ONLY takes into account GLUCOSE, BUN and Na
How can the PLASMA SODIUM concentration be measured more accurately in cases of HYPO/HYPERnatremia?
By ABG
What patients have HYPOtonic HYPOnatremia with an APPROPRIATELY LOW Urine Osmolality (
Those with PRIMARY POLYDIPSIA “psychogenic” (because water EXCRETION by the kidney is partly SOLUTE-dependent, severely limiting solute intake also decrease water excretion thus causing HYPOnatremia with even SMALL increases in fluid intake - seen in patients with CHRONIC ALCOHOL ABUSE (mostly water) and LOW-SOLUTE intake (malnourished)
What patients have HYPOtonic HYPOnatremia with an INAPPROPRIATELY HIGH Urine Osmolality (>100 mosm/kg H2O in the setting of hypotonic hypernatremia)?
Those that have a NON-OSMOTIC ADH-secretion due to TRUE HYPOvolemia, DECREASED ARTERIAL BLOOD VOLUME or NON-PHYSIOLOGIC ADH release resulting in INCREASED total body water and EXTRAcellular FLUID volume (SIADH)
What is the typical Urine Na concentration in patients with SIADH (where the ADH secretion is not physiologic but abnormal)?
Urine Na >40 meq/L because there is increased EXTRAcellular FLUID volume and PHYSIOLOGICALLY, to decrease this volume, Na has to be EXCRETED
What is the typical Urine Na in patients with HYPOnatremia due to NON-OSMOTIC ADH secretion that IS PHYSIOLOGIC such as in TRUE HYPOvolemia (such as blood loss or HF, Nephrotic Syndrome or Cirrhosis)?
Urine Na
Condition in which the Urine Na (ie excreted Na) is >40 meq/L (high), FEna (fractional excretion of Na) “the % of Na that is filtered by the kidney and EXCRETED in the urine” >1% and BUN
SIADH
What is the FEna (fractional excretion of Na) - “the % of Na that is filtered by the kidney and EXCRETED in the urine” used for?
- If FEna is 2%, the problem is RENAL where either excess sodium is lost due to tubular damage, or the damaged glomeruli result in hypervolemia (they do not filter sufficient amounts of blood) resulting in the normal response of sodium wasting by the functioning glomeruli
- If the FEna is INTERMEDIATE (1-2%) the problem is POST-RENAL as in renal tract obstruction, where the value is lower in early disease, but with kidney damage from the obstruction, the value becomes higher
Condition in which Urine Na (ie excreted Na) is 15 mg/dL?
HYPOvolemia (kidney is HOLDING onto Na)
Hemorrhage, Cancers, 3,4-Methylenedioxymethamphetamine (ecstasy), COX-2 inhibitors, NSAIDS, Desmopressin (vasopressin), Opiates, SSRI’s/SNRI’s, endurance exercise, HIV, Rocky Mountain Spotted Fever, Anesthesia, Infections, Positive Pressure Mechanical Ventilation (NPPV - non-invasive positive pressure ventilation), SCLC (small cell lung CA) can all cause what renal syndrome?
SIADH
POST-OP administration of HYPOtonic fluids, THIAZIDE diuretics (chlorthalidone/hctz), use of ecstasy (3,4-Methylenedioxymethe..), OVERHYDRATION associated with extreme exercise and PRIMARY POLYDIPSIA “psychogenic” can result in ACUTE what with what consequences?
ACUTE HYPOnatremia - increased neuronal cell volume (BRAIN SWELLING) - “cerebral edema”
What occurs when the SERUM Na level DECREASES QUICKLY by more than 10 meq/L (ie 135 to 125 meq/L) over 1-3 days?
ACUTE HYPOnatremia with CEREBRAL EDEMA (high-mortality) with SEIZURES, OBTUNDATION, COMA, RESPIRATORY ARREST
What occurs when the SERUM Na level DECREASES by more than 10 meq/L (ie 135 to 125 meq/L) in a course of >3 days?
CHRONIC HYPOnatemia, no cerebral edema
What occurs when HYPOnatremia is OVERLY-RAPIDLY corrected?
OSMOTIC Demyelination Syndrome (high-mortality)
What type of symptoms do patients with CHRONIC HYPOnatremia (125-135 meq/L) present with?
SUBTLE - falls, hip fractures, osteoporosis
When patients have SYMPTOMATIC HYPOnatremia (cerebral edema, seizures, AMS, coma) or due to SIADH, what should be the treatment?
HYPERtonic SALINE (3%)
When patients have HYPOnatremia due to TRUE HYPOvolemia, what should be their treatment?
NORMAL SALINE (0.9%)
When SHOUD treatment with SALINE be stopped for HYPOnatremia?
When SYMPTPOMS resolve and serum Na correction should NOT EXCEED 10 meq/L in the FIRST 24 HOURS or 18 meq/L in the FIRST 48 HOURS while monitoring serum Na level every 2-4 hours
How is ACUTE HYPOtonic HYPOnatremia with SYMPTOMS of SEIZURES or COMA?
100 mL BOLUS of 3% SALINE (or 2 mL/kg) repeated up to TWO (2) times while monitoring serum Na level every 2-4 hours
Patients with SYMPTOMATIC SIADH and HIGHLY concentrated urine (
With 3% SALINE
While correcting HYPOnatremia in a patient with SYMPTOMATIC SIADH and HIGHLY concentrated urine (>750 mosm/kg H2O) with the appropriate 3% SALINE, the patient begins having WATER diuresis and begins correcting their HYPOnatremia too quickly, what can be done BESIDES STOPPING THE 3% SALINE infusion?
Give D5W (5% dextrose in water) or DESMOPRESSIN
Irreversible neurologic deficits such as PROGRESSIVE QUADRIPARESIS, SPEECH/SWALLOWING disorders, COMA, LOCKED-IN Syndrome while CORRECTING HYPOnatremia are associated with?
Osmotic Demyelination Syndrome caused by OVER-CORRECTION (or too rapid) of HYPOnatremia (>10 meq/L/24 HOURS or >18 meq/L/48 HOURS)
How are patients with ASYMPTOMATIC HYPOtonic HYPOnatremia (due to SIADH, HYPERvolemic HYPOnatremia or otherwise) treated?
WATER RESTRICTION (TOTAL INTAKE - both PO and IV, MUST be LESS than TOTAL OUTPUT), D/C offending drugs, Give DIURETICS (furosemide), Demeclocycline, Vasopressin Receptor Antagonists (-“vaptan”) and ensure adequate SOLUTE intake (nutrition)
HOW is HYPOtonic HYPOnatremia treated when the CAUSE is HYPERglycemia (called “pseudohyponatremia”)?
By the treatment of the HYPERglycemia with INSULIN, the SODIUM will correct by itself as water moves BACK into the INTRAcellular compartment following the GLUCOSE pushed there by insulin
HOW is HYPOtonic HYPOnatremia treated when the CAUSE is HYPERlipideia or HYPERproteinemia (called “pseudohyponatremia”)?
By the treatment of the UNDERLYING HYPERlipideia or HYPERproteinemia, the SODIUM will correct by itself as water moves BACK into the INTRAcellular compartment f
Although CORRECTING the SODIUM in a patient with SYMPTOMATIC HYPOnatremia (COMA, AMS, Cerebral Edema, Seizures) with 3% SALINE by NO MORE than 10 meq/L/24 HOURS or NO MORE than 18 meq/L/48 HOURS, RAPIDLY increasing the SODIUM concentration by WHAT range over the FIRST 24 HOURS is SUFFICIENT?
4-6 meq/L
Commonly seen in CRITICALLY-ILL patients, serum Na levels >145 meq/L are called what?
HYPERnatremia (high-morbidity and mortality)
How do you treat a patient with ASYMPTOMATIC HYPERvolemic HYPOnatremia (CHF, Cirrhosis, Nephrotic Syndrome)?
Treat UNDERLYING cause, RESTRICT BOTH Na and Fluids, Give DIURETICS (furosemide) and Vasopressin Receptor Antagonists (-“vaptan”)
What is the most COMMON cause of HYPERnatremia?
FAILURE to adequately replace water loss (elderly & infants, HYPOTHALAMIC lesions)
Urinary/GI fluid losses, Diuretic therapy and Osmotic diuresis WITHOUT adequate FLUID replacement can result in what condition?
HYPERnatremia
What is the cause of CENTRAL Diabetes Insipidus (DI) - Langerhans Cell Histiocytosis, Neurosurgery, Trauma, Sarcoidosis, Wegener Granulomatosis, Malignancy, Anorexia?
DECREASED release of ADH by the POSTERIOR PITUITARY
What is the cause of NEPHROGENIC Diabetes Insipidus (DI) - LITHIUM, foscarnet, amphotericin B, HYPERcalcemia?
Partial or Complete RESISTANCE of the KIDNEY to the effects of ADH
When PREGNANT women get Diabetes Insipidus (DI), during their pregnancy, it is most likely due to what condition?
GESTATIONAL DI, caused by circulating placental VASOPRESSINASE (enzyme that breaks down vasopressin causing water wasting)
What is ADIPSIC Diabetes Insipidus?
When a lesion affects BOTH the POSTERIOR PITUITARY gland and the HYPOTHALAMIC THIRST CENTER - sarcoidosis - thereby not only resulting in INADEQUATE ADH release, but also failing to trigger THIRST resulting in SEVERE HYPERnatremia
When a patient’s URINE VOLUME is >3 L/24 HOURS, what is that called? What does it cause?
POLYURIA, causing HYPERnatremia (except for in PRIMARY POLYDIPSIA “psychogenic” where HYPOnatremia is seen because pt just keeps drinking water) and OSMOTIC Diuresis
ABRUPT-ONSET Polyuria is most likely caused by?
CENTRAL Diabetes Insipidus (DI)
What is NORMAL urine OSMOLALITY?
300 mosm/kg H2O
OSMOTIC DIURESIS, occurs when substances that CANNOT be RE-ABSORBED by the KIDNEYS such as GLUCOSE (HYPERglecemia seen in DM) pass through the renal tubules and take water out with them. Urine OSMOLALITY during OSMOTIC diuresis is what?
NORMAL, 300 mosm/kg H2O
What is the URINE OSMOLALITY in patients with PRIMARY POLYDIPSIA and Diabetes Insipidus (DI)?
.
What is the TYPICAL SERUM Na concentration in PRIMARY POLYDIPSIA? What about in CENTRAL Diabetes Insipidus (DI)?
PRIMARY Polydipsia 142 meq/L - “HYPERnatremia”
Because PRIMARY POLYDIPSIA is a PSYCHIATRIC disorder and NOTHING is wrong with the POSTERIOR PITUITARY or KIDNEYS, what happens to the URINE OSMOLALITY during a WATER DEPRIVATION test?
Urine CONCENTRATES appropriately to >600 mosm/kg H2O
Because CENTRAL Diabetes Insipidus (DI) is a POSTERIOR PITUITARY disorder but NOTHING is wrong with the KIDNEYS, what happens to the URINE OSMOLALITY during a WATER DEPRIVATION test?
Urine FAILS to CONCENTRATE (inadequate or NO ADH release) and remains at 600 mosm/kg H2O (the same response to given desmopressin occurs with GESTATIONAL Diabetes Insipidus as well, which is caused by circulating placental vasopressinase enzymes that break down adequately-released vasopressin or “ADH” but cannot break down desmopressin)
Because NEPHROGENIC Diabetes Insipidus (DI) is an ADH-RECEPTOR DISORDER in the RENAL TUBULES of the KIDNEY, but NOTHING is wrong with the POSTERIOR PITUITARY, what happens to the URINE OSMOLALITY during a WATER DEPRIVATION test?
Urine FAILS to CONCENTRATE (NO respone by the KIDNEY to normally-released ADH by the POSTERIOR PITUITARY) and remains at
In the ABSENCE of HYPOVOLEMIC SHOCK, how should CIRCULATORY COLLAPSE be treated FIRST to restore organ HYPOperfusion prior to treating HYPERnatremia caused by the HYPOvolemia?
With ENOUGH ISOTONIC (normal, 0.9%) SALINE to CORRECT ORGAN HYPOperfusion (shock), then CHANGE to D5W (5% dextrose) to CORRECT the HYPERnatremia based on CALCULATED WATER DEFICIT, DO NOT GIVE NS BOLUSES (can cause cerebral edema) and DO NOT CORRECT HYPERnatremia any faster than 10 meq/L/24 HOURS carefully monitoring SERUM Na Concentration every 2-4 HOURS during correction
Because NEPHROGENIC Diabetes Insipidus (DI) does NOT respond to DEMOPRESSIN, how do you treat it?
THIAZIDE Diuretics - chlorthalidone/hctz - (increase PROXIMAL TUBULE Na and water RE-ABSORPTION), NSAIDS, LOW Na, and LOW PROTEIN diet, D/C LITHIUM if possible
How is the RISK of LITHIUM-ASSOCIATED NEPHROGENIC Diabetes Insipidus (DI) or its PROGRESSION due to collecting duct toxicity) DECREASED?
By adding AMILORIDE (a potassium-sparing diuretic) which BLOCKS LITHIUM uptake in the collecting duct limiting toxicity
What effect can DIURETICS have on LITHIUM?
INCREASE SERUM levels because the resulting diuretic-induced HYPOvolemia causes PROXIMAL TUBULE RE-ABSORPTION of LITHIUM
Besides 3% SALINE, what are THREE (3) other HYPERtonic IV solutions?
D10W (10% dextrose in water), D51/2NS (5% dextrose in 0.45% saline) and D5NS (5% dextrose in 0.9% or “normal” saline)
What is considered HYPOkalemia and HYPERkalemia?
HYPOkalemia - serum K 5.0 meq/L
Cellular REDISTRIBUTION (pushed out of cells), KIDNEY or GI LOSSES and DECREASED INTAKE of this ELECTROLYTE manifest as MUSCLE WEAKNESS, CRAMPS, RHABDOMYOLYSIS (
K (HYPOkalemia)
What is the most COMMON cause of HYPOkalemia?
The use of DIURETICS
What effect does MARKED LEUKOCYTOSIS (C.diff infection, myeloproliferative disorders like CML) have on SERUM POTASSIUM?
DECREASES it because it is DRIVEN inside of cells (pseudoHYPOkalemia)
An ASIAN or MEXICAN with personal SYMPTOMS of and FAMILY h/o ACUTE EPISODIC MUSCLE WEAKNESS following a HIGH-CARBOHYDRATE meal or STRENUOUS EXERCISE that has been treated in the past with INTERFERON therapy or had THYROTOXICOSIS has what SYNDROME?
HYPOkalemic Periodic Paralysis
ALDOSTERONE, INCREASED TUBULAR FLOW to the Collecting Duct of the nephron resulting in Na delivery to this area, can cause what ELECTROLYTE over excretion and thus deficiency?
K (HYPOkalemia)
What happens to Kidney POTASSIUM EXCRETION in a patient who has increased GI LOSSES (violent VOMITING episodes - emesis)?
It is reduced to
What does it mean, in a HYPOkalemic patient, when their Urine POTASSIUM EXCRETION is >30 meq/L?
ONGOING URINE-POTASSIUM LOSSES
Why do you commonly see HYPOkalemia in patients with HTN?
Because in states of HTN, usually caused by ELEVATED RENIN-ALDOSTERONE, the ALDOSTERONE causes increased POTASSIUM EXCRETION and H¯ ion EXCRETION (acidifying urine)
HYPOkalemia usually occurs together with which ACID-BASE disorder?
METABOLIC ALKALOSIS (diuretics, vomiting, NGT suction, Mg deficiency)
Bartter and Gitelman syndromes are CONGENITAL disorders with THICK-ASCENDING LIMB of the LOOP of HENLE (Bartter - LOOP diuretics) and DISTAL CONVOLUTED TUBULE (Gitelman - THIAZIDE diuretics) abnormalities that result in what ACID-BASE DISORDER?
HYPOkalemic METABOLIC ALKALOSIS
What CONGENITAL syndrome that results in HYPOkalemic METABOLIC ALKALOSIS when LOOP DIURETICS (furosemide) are used, due to abnormalities in the THICK-ASCENDING LIMB of the LOOP of HENLE is MIMICKED by the CHRONIC use of AMINOGLYCOSIDE ANTIBIOTICS (amikacin, tobramycin, gentamycin, streptomycin?)
BARTTER Syndrome
What does a Urine K:Cr ratio >20 meq/L suggest, what about when its
Urine K:Cr ratio >20 meq/L - Kidney Potassium Wasting
Urine K:Cr ratio
How do you replete K in a patient with a LARGE K deficit with symptoms of SKELETAL and CARDIAC muscle dysfunction?
- IV 40 meq/L of KCl at 20 meq/h WTHOUT addition of sodium bicarb or glucose initially (drives K into cells)
- If less serious, can be given PO
What formulation of POTASSIUM should be used in patients with concomitant metabolic acidosis due to RTA?
Potassium Citrate
What ELECTROLYTE DEFICIENCY contributes GREATLY to HYPOkalemia and its correction can help urine POTASSIUM loss?
MAGNESIUM (Mg)
Decreased RENIN-ANGIOTENSIN-ALDOSTERONE activity (acute/chronic kidney disease), ASCENDING muscle weakness, paralysis, ARRHYTHMIAS with ECG changes (TALL, PEAKED T-waves, short QT, increased PR and QRS, small P waves, Bradycardia) are seen in what electrolyte disturbance?
HYPERkalemia
When ECG changes are noted in the setting of serum K >5.0 what must be done?
EMERGENCY THERAPY
What can happen to SERUM POTASSIUM if SEVERE LEUKOCYTOSIS (>120,000) or SEVERE THROMBOCYTOSIS (>600,000) occurs?
INTRAcellular POTASSIUM is released into the INTERcellular space causing pseudoHYPERkalemia
What electrolyte disturbance can be caused by MECHANICAL TRAUMA and CRUSH injuries due to extravasation from the INTERcellular compartment?
pseudoHYPERkalemia
Why does the Kidney EXCRETE POTASSIUM (K) in response to ALDOSTERONE released by the ADRENAL glands?
Because ALDOSTERONE causes INCREASED Na and WATER RE-ABSORPTION and K and H EXCRETION (Na-K pumps)
What patients can develope HYPERkalemia simply from DIETARY POTASSIUM intake?
Those with a DECREASED GFR
If HYPERkalemia occurs in a patient with a GFR >20 mL/min and the RENIN-ANGIOTENSIN-ALDOSTERONE system is normal, what could be the cause?
Defect in the POTASSIUM (K) SECRETION in the COLLECTING DUCT
Drugs that INTERFERE with POTASSIUM SECRETION by the COLLECTING DUCT thus cause or worsen HYPERkalemia are interfering with the RENIN-ANGIOTENSIN-ALDOSTERONE system (this happens with chronic DM and HIV as well, in the condition of HYPOreinemic - HYPOaldosteronism) and are especially seen in drug COMBINATIONS such as?
ACE-I/ARB’s + SPIRONOLACTONE in the setting of Chronic Kidney Disease (CKD)
What can cause INJURY to the COLLECTING DUCT of the nephron resulting in HYPERkalemia as the COLLECTING DUCT cannot PROPERLY SECRETE K into the urine?
Sickle Cell Nephropathy, Chronic Glomerulopathy, Urinary Obstruction
When a disease/drug/congenital syndrome results in DECREASED ALDOSTERONE production (adrenal insufficiency), this results in what electrolyte disturbance?
HYPERkalemia
What electrolyte disturbance is seen in patients with a URETERO-JEJUNOSTOMY (high cancer rate) due to the ABSORPTION of this electrolyte by the JEJUNUM which is excreted in the urine?
HYPERkalemia
How is SYMPTOMATIC HYPERkalemia (muscle and cardiac manifestations) treated?
- Stabilize membranes: IV CaCl or Ca-gluconate every 5 min until ECG changes NORMALIZE, UNLESS pt is experiencing DIGOXIN TOXICITY in which IV Ca is CONTRAINDICATED and as such, you MUST use alternative treatment such as driving K into cells using IV INSULIN + GLUCOSE (when serum glucose
How do you treat HYPERkalemia when it occurs TOGETHER with METABOLIC ACIDOSIS?
SODIUM BICARBONATE (NaHCO3)
How is SEVERE HYPERkalemia treated in the setting of SEVERE KIDNEY FAILURE as conventional treatments that rely on KIDNEY FUNCTION cannot be used?
Dialysis
NSAIDS, COX-2 Inhibitors, ACE-I/ARB’s and Spironolactone all contribute to this electrolyte disturbance and MUST be D/C or MODIFIED in the setting of the disturbance?
HYPERkalemia
What MEDICATION can be used to DECREASE total body potassium (K) in patients with Chronic Kidney Disease (CKD) or CHF?
LOOP DIURETICS
How is MILD to MODERATE, ASYMPTOMATIC HYPERkalemia controlled?
DIETRARY POTASSIUM (K) restriction
What is considered HYPOphosphatemia and whom is it usually seen in?
Serum P
When SERUM PHOSPHATE (P) are
When P
How is HYPOphosphatemia treated?
By treating the UNDERLYING cause and ORAL SUPPLEMENTATION only if SYMPTOMATIC or chronic PHOSPHATE (P) WASTING
Why is IV PHOSPHATE not usually given (unless serum P
IV phosphate can cause ACUTE KIDNEY INJURY and HYPOcalcemia but when administered (when serum P
What ELECTROLYTE is DECREASED as PHOSPHATE (P) is INCREASED?
CALCIUM
Disturbances in serum POTASSIUM (K) and PHOSPHATE (P) both manifest with this COMMON SYMPTOM?
WEAKNESS
What is considered HYPERphosphatemia and whom is this usually seen in?
Serum P >4.5 mg/dL, seen in patients with ADVANCED Chronic Kidney Disease (CKD) or with INCREASED CELL TURNOVER (tumor lysis syndrome) or CELL INJURY or EXOGENOUS administration
How are patients with HYPERphosphatemia treated in the setting Chronic Kidney Disease (CKD)?
With PHOSPHATE (P) BINDERS to limit intestinal absorption of PHOSPHATE (P) - SEVELAMER (Ca-carbonate and Ca-acetate can also be used)
What is considered SEVERE HYPERphosphatemia that requires DIALYSIS?
Serum P >10 mg/dL
In the setting of TUMOR LYSIS SYNDROME with resultant SEVERE electrolyte disturbances such as HYPERkalemia, HYPERuricemia, HYPERphosphatemia (thus HYPOcalcemia) what MUST BE DONE to avoid DEATH?
EMERGENT DIALYSIS
What TWO (2) mechanisms are responsible for the TIGHT SYSTEMIC pH maintenance?
By BOTH the KIDNEYS (mainly via bicarb HCO3 regulation) and LUNGS (mainly via CO2 regulation)
The cause of MOST ACID-BASE disturbances is apparent by examining what TWO (2) factors on an ARTERIAL ABG?
pH and PCO2 as well as the VENOUS electrolyte measurement, primarily the bicarbonate (HCO3)
An arterial PCO2 >40 mmHg suggests? What if the arterial PCO2
PCO2 >40 mmHG - RESPIRATORY Acidosis (more CO2 dissolved in blood makes it more acidic)
PCO2
A SERUM bicarbonate HCO3 24 mmol/L?
HCO3 24 mmol/L - METABOLIC Alkalosis
What MUST be determined in an ACID-BASE disorder?
- What is the DOMINANT acid-base disorder (dictated by the pH)
- What is the SECONDARY (compensatory) RESPONSE (dictated by the PCO2 and HCO3)
IF the MEASURED values (PCO2, HCO3) fall outside of the PREDICTED compensatory response, the acid-base disorder is MIXED (as in salicylate toxicity)
Loss of serum HCO3, Decreased excretion of acid, Imbalance between production/consumption of endogenous acids or Ingestion/IV administration of exogenous acids can cause what ACID-BASE disorder?
METABOLIC Acidosis
ACETAMINOPHEN poisoning, Vitamin D deficiency, HYPERparathyroidism (increased Ca), Osmotic diuresis, Osteomalacia, Kidney transplant Proximal TYPE-2 RTA (Fanconi Syndrome), Rickets and the HIV drug TENOFOVIR (used as art of the current “Ten-Em-Ef” ART single-pill combination therapy), CHRONIC Diarrhea and INTRAcellular uptake (re-feeding syndrome, treating DKA with insulin, parathyroidectomy causing HUNGRY-BONE SYNDROME and RESPIRATORY Alkalosis) are all causes of this ELECTROLYTE disturbance?
HYPOphosphatemia
What ELSE must be determined when the ACID-BASE disorder is METABOLIC Acidosis?
Whether or not there is an ANION GAP
A RAISED anion gap (just called “anion gap” or “increased anion gap”) in METABOLIC Acidosis (the only acid-base disturbance where an anion gap is analyzed) will tell you what about the METABOLIC Acidosis?
It tells you whether the DECREASED SERUM HCO3 (metabolic acidosis) is due to the presence of an ADDITIONAL, UNMEASURED ACID (lactate or ingested acid) that is raising the anion gap or whether the DECREASED SERUM HCO3 (metabolic acidosis) is due to a LOSS or LACK of PRODUCTION of SERUM HCO3 which CAUSES the SERUM Chloride (Cl¯) to INCREASE in order to maintain electroneutrality, in which case the anion gap would be NORMAL
What are the ONLY TWO (2) possible types of METABOLIC Acidosis scenarios in relation to anion gap?
IINCREASED anion gap (or just “anion gap”) or NORMAL anion gap METABOLIC Acidosis
What is the ANION GAP equation?
Anion Gap = SERUM Na - [SERUM Cl¯+SERUM HCO3¯]
What occurs with serum PHOSPHATE (P) in FANCONI Syndrome (Proximal RTA-II)
Serum PHOSPHATE (P) is DECREASED
What is the NORMAL range of the ANION GAP?
10 meq/L
What UNMEASURED anion(s) can affect the calculation of the ANION GAP and HOW is it affected?
- ALBUMIN (and light-chains) - NORMAL is 4.0 g/dL
- For EVERY 1 g/dL DECREASE of serum albumin from NORMAL, the expected or “normal” anion gap also DECREASES by 2.3 meq/L
In METABOLIC Acidosis (serum HCO3 10 meq/L) and this has been CORRECTED for abnormal serum ALBUMIN “for EVERY 1 g/dL DECREASE of serum albumin from NORMAL (4.0), the expected or “normal” anion gap also DECREASES by 2.3 meq/L” what OTHER DETERMINATION must be made?
- Whether the serum HCO3 was NORMAL BEFORE the development of the acidosis or if there was a PRE-EXISTING metabolic abnormality BEFORE the acidosis occurred that created the anion gap. This is done by calculating the CORRECTED HCO3 based on THE CHANGE in the anion gap (DELTA anion gap)
- CORRECTED HCO3 = 24 meq/L - Δ anion gap meq/L
- IF the MEASURED HCO3 > CORRECTED HCO3 it suggests that there is a concomitant METABOLIC Alkalosis in ADDITION to the INCREASED anion gap METABOLIC Acidosis
- IF the MEASURED HCO3
How is the CORRECTED HCO3 calculated to determine the CHANGE in anion gap or “Δ anion gap”?
CORRECTED HCO3 = 24 meq/L - Δ anion gap meq/L
ACUTE/CHRONIC Kidney Disease, ALCOHOLIC Ketoacidosis, DKA, Lactic Acidosis, Poisoning with (Methanol, Ethylene/Diethylene/Propylene Glycol, CO, Acetaminophen), Metformin, Propofol, Salicylates, Liver Failure, Malignancy and G6PD ALL cause what ACID-BASE DISORDER?
INCREASED anion gap METABOLIC Acidosis
What is the most common form of INCREASED anion gap METABOLIC Acidosis?
LACTIC ACIDOSIS (serum lactate >4 md/dL), TYPES A & B
Type A - tissue HYPOperfusion
Type B - no hypoperfusion
When LACTIC ACIDOSIS (causing INCREASED anion gap METABOLIC Acidosis) is caused by ACETAMINOPHEN toxicity, what is the injury?
DIRECT Liver Injury by acetaminophen
In SEVERE ASTHMA, when HIGH-DOSES of β2-agonists and CORTICOSTEROIDS are used as well as the RESPIRATORY Alkalosis that develops (due to rapid breathing thus blowing off CO2, decreasing it), this type of ACIDOSIS develops?
- LACTIC ACIDOSIS (causing INCREASED anion gap METABOLIC Acidosis)
- So, in severe ASTHMA, treated with β2-agonists and CORTICOSTEROIDS, you would see BOTH a RESPIRATORY Alkalosis as well as an INCREASED anion gap METABOLIC Acidosis
How is Lactic Acidosis treated?
Treating the UNDERLYING cause as well as IVF if caused by HYPOperfusion such as in HYPOvolemic shock
When is the ONLY time, Sodium Bicarbonate (NaHCO3) should be used to treat LACTIC ACIDOSIS?
When pH ≤7.1 (and ONLY to raise it to 7.2) especially in those with CARDIOVASCULAR compromise
What ACID-BASE disorder do SEVERE ASTHMA, prolonged PROPOFOL administration (>48 HOURS usually in an ICU setting) and ACETAMINOPHEN toxicity cause?
ALL cause LACTIC ACIDOSIS (which is an INCREASED anion gap METABOLIC Acidosis), however SEVERE ASTHMA also causes a concomitant RESPIRATORY Alkalosis
A patient receiving prolonged sedation >48 HOURS in the ICU with this medication, develops LACTIC ACIDOSIS (which is an INCREASED anion gap METABOLIC Acidosis) with RHABDOMYOLYSIS, HYPERLIPIDEMIA and ECG shows J-point elevation, what’s the medication used?
PROPOFOL
How is PROPOFOL - caused LACTIC ACIDOSIS (which is an INCREASED anion gap METABOLIC Acidosis) with RHABDOMYOLYSIS, HYPERLIPIDEMIA and ECG showing J-point elevation TREATED?
D/C the PROPOFOL and treat supportively, unless SEVERE ACIDOSIS which may require DIALYSIS
What is the cause of this type of INCREASED anion gap METABOLIC Acidosis that p/w CONFUSION, SLURRED SPEACH and ATAXIA (loss of full control of body movements) in a patient with SHORT-BOWEL syndrome that has undergone recent SMALL BOWEL RESECTION or a JEJUNO-ILEAL bypass and has ingested a large CARBOHYDRATE meal and NORMAL serum LACTATE levels?
D-Lactic Acidosis (D-isomer of lactic acid), which is NOT DETECTED in SERUM LACTATE labs (different isomer)
How is D-Lactic Acidosis - an INCREASED anion gap METABOLIC Acidosis - (D-isomer of lactic acid seen in short bowel syndrome) TREATED?
With METRONIDAZOLE/Neomycin (against bowel flora which produce the isomer) as well as dietary CARBOHYDRATE RESTRICTION
What type of ACID-BASE disorder is seen in DKA?
INCREASED anion gap METABOLIC Acidosis (can be NORMAL anion gap as well if there is no hypovolemia, usually caused by excretion of the ketoacids “acetoacitate and β-hydroxybutyrate”)
In the presence of INSULIN DEFICIENCY, INCREASED CATECHOLAMINES and GLUCAGON an INCOMPLETE OXIDATION of FATTY-ACIDS occurs which leads to increased production of acetoacetate and β-hydroxybutyrate. What is this process called and what ACID-BASE disturbance does it cause?
DKA, causes an INCREASED anion gap METABOLIC Acidosis (but can cause “NORMAL anion gap” as well if there is no hypovolemia, usually caused by excretion of the ketoacids “acetoacitate and β-hydroxybutyrate”)
How is DKA and the resulting INCREASED anion gap METABOLIC Acidosis (can be NORMAL anion gap as well if there is no hypovolemia, usually caused by excretion of the ketoacids “acetoacitate and β-hydroxybutyrate”) TREATED?
INSULIN administration WITH GLUCOSE/POTASSIUM as needed (DKA patients tend to be HYPOkalemic)
When should DKA also be treated with SODIUM BICARBONATE (NaHCO3)?
ONLY when the pH
Does the HYPOphosphatemia require treatment when treating DKA?
NOT unless SEVERE symptoms specifically caused by this deficiency (corrects by itself)
In patients with CHRONIC ALCOHOL abuse, with POOR NUTRITION, with N/V and resulting HYPOvolemia, INCREASED CATECHOLAMINES resulting in mobilization of FATTY-ACIDS and increased production of specifically β-hydroxybutyrate. What is this process called and what ACID-BASE disturbance does it cause?
ALCOHOLIC Ketoacidosis (causing INCREASED anion gap METABOLIC Acidosis)
What does the NITROPRUSSIDE assay measure and why is it so limited in its use?
Measures KETOACIDOSIS, however it can ONLY detect ACETONE (isopropyl alcohol ingestion) and ACETOACETATE, but NOT β-hydroxybutyrate (which is seen in DKA and Alcoholic DKA)
How does KETOACIDOSIS happen?
Starvation (or fasting), DM, ALCOHOL w/malnutrition result in poor INTRAcellular GLUCOSE availability, causing increased circulating CATECHOLAMINES and the mobilization of LIVER GLUCAGON stores which INCOMPLETELY oxidize FATTY ACIDS into acetoacitate (an acid) which is subsequently made into acetone (not an acid) and β-hydroxybutyrate (another acid) resulting in KETOACIDOSIS
Why does the ingestion of ISOPROPYL ALCOHOL not result in KETOACIDOSIS?
Because ISOPROPYL ALCOHOL is metabolized into ACETONE, which is NOT an ACID nor is it further metabolized (unlike acetoacetate which IS an acid and IS further metabolized into β-hydroxybutyrate, another acid)
What is the predominant ACID causing the KETOACIDOSIS and hence the INCREASED anion gap METABOLIC Acidosis in ALCOHOLIC KETOACIDOSIS?
β-hydroxybutyrate (NOT detected by the nitroprusside assay which only detects acetone and acetoacetate)
How is ALCOHOLIC Ketoacidosis (causing INCREASED anion gap METABOLIC Acidosis) TREATED?
With NUTRITION or if SEVERE, same as with DKA treatment (THIAMINE - Vit B1, followed by INSULIN administration WITH GLUCOSE/POTASSIUM as needed)
Poisoning with these SUBSTANCES is HIGHLY LETHAL as they present with SEVERE, INCREASED anion gap METABOLIC Acidosis, with an OSMOLAL GAP >10 mosm/kg H2O (MEASURED osmolality - CALCULATED osmolality) and is caused by the breakdown (metabolism) of the PARENT COMPOUNDS into ACIDS as well as contributing LACTIC ACIDOSIS making this scenario into the MOST SEVERE type of INCREASED anion gap METABOLIC Acidosis there is. What are these SUBSTANCES?
METHANOL, Ethylene Glycol, DiEthylene Glycol, Methylene Glycol and Propylene Glycol (METHANOL and ALL of the GLYCOLS) - ANTIFREEZE-related compounds
What is the “INCREASED anion gap” due to in POISONING with Ethylene Glycol, DiEthylene Glycol, Methylene Glycol and Propylene Glycol and what can happen if a patient is NOT seen RIGHT AWAY after ingestion of the poisons?
The INCREASED anion gap is due to the PARENT COMPOUND (ie Ethylene Glycol, DiEthylene Glycol, Methylene Glycol and Propylene Glycol) however if the POISONED patient is NOT seen right away, the parent compound can be COMPLETELY METABOLIZED thus resulting in a NORMAL anion gap METABOLIC ACIDOSIS
How does a patient with Ethylene Glycol POISONING present?
Flank Pain or Oliguria due to the PRECIPITATION of CALCIUM OXALATE in the renal tubules causing ACUTE KIDNEY INJURY with HYPOcalcemia and NEPHROcalcinosis (deposition of calcium in the kidney parenchyma) with the presence of CALCIUM OXALATE crystals in the URINE sediment