Rnwk4- 5-3 Internal Med Interpreting Acid/base Disturbances

Front 1

Normal values for pH, PCO2, PO2, HCO3-, O2 sats:

Formula for normal PO2?

Causes of hypoxia?

Back 1

pH 7.35-7.45 (7.4), PCO2 35-45 (40), PO2 80-100 (90), HCO3- 22-26 (24), O2 92%-100%

100 - (1/3)age= around 92% for me

V/Q mismatch - COPD, pneumonia, shunting (ARDS), diffusion abnormalities (Hamman Rich, sarcoid), hypoventilation, low O2 fraction, high altitude

Front 2

Acidosis = pH < ?
Alkalosis = pH > ?
Hypoxia = pO2 < ?
Hypercapnia = pCO2 > ?
Hypocapnia = pCO2 < ?

ABG normals for Na, K, Cl, HCO3?

Anion gap calculation? What's normal?

Back 2

acidosis = pH <7.35
alkalosis = pH > 7.45
hypoxia = pO2 < 60
hypercapnia = pCO2 > 45
hypocapnia = pCO2 < 35

ABG - Na 135-145 (140), K 3.5-5 (4), Cl 98-106 (103), HCO3 21-28 (24)

AG = [Na] - [Cl + HCO3]
normal = 10-14 relects the concentration of anions that arent routinely measured (sulfates, phosphates, acetoacetic acid, beta hydroxybutric acid)

Front 3

What test is ordered to completely evaluate acid base states?

What does RTA mean?

Back 3

BMP

renal tubular acidosis

Front 4

pH, CO2 go in opposite directions:

pH, CO2 go in same direction:

respiratory compensation for metabolic acidosis,alkalosis:

metabolic compensation for acute respiratory acidosis, alkalosis:

Back 4

respiratory acidosis/alkalosis

metabolic acidosis/alkalosis

met acid: down 1.2 pCO2/1 HCO3-
met alka: up 0.7 pCO2/1 HCO3-

resp acid: up 1 HCO3/10 PCO2, pH down 0.8/10 PCO2
resp alka: down 2 HCO3/10 PCO2, pH up 0.8/10 PCO2

Front 5

metabolic compensation for chronic resp. acidosis, alkalosis:

RTA Type I: where, what's affected, causes?

RTA Type II: where, what's affected, causes?

Back 5

resp acid: up 3-4 HCO3/10 PCO2
resp alka: down 4-5 HCO3/10 PCO2

RTA Type I: distal tubule, low acid secretion to urine, Sjogren's, SLE

RTA Type II: proximal tubule, low absorption of HCO3-, myeloma, heavy metal poisoning, Wilson's

Front 6

Causes of AG metabolic acidosis? (CT MUDPILES)

Back 6

CO, cyanide
Toluene poisoning
Methanol
Uremia (renal failure) increase: BUN, creatinine, sulfates, phosphates as unmeasured anions
DKA- increase glucose, starvation, alcohol abuse, Ac Ac, BHD
Paraldehyde
INH, Iron
Lactic acidosis
Ethylene glycol
Salicylate

Front 7

Causes of non-AG metabolic acidosis? (HARDUPS) - general mechanism?

Back 7

loss of HCO3- and Cl rises (hyperchoremic met acid)

Hyperalimentation
Addison's, acetazolamide
RTA
Diarrhea
Ureteral/ileal diversion
Pancreatic fistula
Spironolactone

Front 8

How do you measure the HCO3 deficit in a met. acidosis pt?

Treatment?

Metabolic alkalosis - general acid/base problem?

Two most common causes of met. alkalosis?

Back 8

HCO3 deficit = desired HCO3 - measured HCO3 (.5x wt in kg)

First treat the underlying cause --
Give for CV compromise when pH <7.2, HCO3 <10
Give NaHCO3 1 amp 8.5% 50mEq/50cc tablets

Cl- loss, HCO3- excess

vomiting, diuretics

Front 9

Causes of metabolic alkalosis? (CLEVER PD)

Back 9

Contraction (volume)
Licorice
Endocrine (Conn's, Cushing's, Bartter's)
Vomiting
Excess Alkali
Refeeding alkalosis
Previous Hypercapnia
Diuretics

Front 10

Urine Cl <10-20, improves with saline, low serum Cl and volume

Three common causes?

Three causes of unresponsive Cl? give urine CL ranges....

Tx for metabolic alkalosis?

Back 10

Cl responsive alkalosis

vomiting, diuretics, NG suction

endocrine - Bartter's, Cushings, severe K+ depletion, hyperaldo- urine CL? 10-20 mEq/l

First treat underlying cause!
then.. NaCl, KCl, Mg, spironolactone for mineralocorticoid excess

Front 11

Causes of respiratory acidosis?

_____ pH, _____ PCO2, _____ HCO3-

Tx?

Back 11

anything that causes hypoventilation - CNS, drugs, CVA, pneumonia, pulm edema, PTX, COPD, restrictive disease

low pH, high PCO2, elevated HCO3

establish airway, suction, b-agonist tx, mechanical ventilation

Front 12

Causes of respiratory alkalosis? (CHAMPS)

raised lactic acid = ______ mortality.

Back 12

CNS
Hyperventilation
Anxiety
Mechanical ventilation
Progesterone
Salicylates/sepsis

raised mortality

Front 13

3 steps in ABG analysis?

Back 13

Step 1: check pH (<7.35 = acidosis, >7.45 = alkalosis)

Step 2: pCO2 and pH direction (same = metabolic, opposite = respiratory)

Step 3: actual to expected pH: pH change 0.08 (+-.02) for each -10 PCO2? if not, then metabolic component

Front 14

using Three step analysis to prove something is respiratory alkalosis...
a. PaCO3 decreased 10 to 30mmHg what should pH be?

Back 14

assuming norm for pH (7.4) it should increase .08 for every 10mmHg decrease

Front 15

If pH calculated out and it is higher than it should be?

Back 15

1. there must be a concomitant metabolic alkalosis

Front 16

If pH is calculated out and it is lower than it should be ?

Back 16

then there must be a concomitant metabolic acidosis

Front 17

pH 7.58, PCO2 20:

pH 7.16, PCO2 70:

pH 7.5, PCO2 50:

Back 17

pure respiratory alkalosis (opposite direction, PCO2 change = 20, pH - .16)

pure respiratory acidosis (opposite direction, PCO2 change of 30, pH - .24)

metabolic alkalosis - pH, PCO2 same direction

Front 18

pH 7.25, PCO2 20:

pH 7.5, PCO2 20:

pH 6.8, PCO2 60:

Back 18

metabolic acidosis - pH PCo2 same direction

resp. alkalosis with metabolic acidosis - opposite direction, but pH lower than expected

resp and metabolic acidosis - opposite direction, pH is lower than expected

Front 19

Describe the three types of type B lactic Acidosis... You only need to know the most common type and causes

Back 19

B1- systemic disorders- DM, liver failure, sepsis, seizure (MOST COMMON TYPE) Usually type A
B2- drugs/toxins- ethanol, methanol, ethylene glycol, ASA
B3- congenital errors- GGPD deficiency

Front 20

Describe the Type A lactic acidosis...

Back 20

tissue hypoxia- shock, sever anemia, heart failure, CO poisoning