Renal

Question 1

Calculate delta-delta only if:

Answer 1

You have anion gap

Question 2

Calculate compensation only if:

Answer 2

You have 1 disorder

Question 3

Compensation: Metabolic acidosis

Answer 3

Winter’s

Expected PCO2=1.5 [bicarb]+8 +/- 2

Question 4

Compensation: Metabolic Alkalosis

Answer 4

Expected PaCO2= 0.7 [HCO3] + 20 +/- 5

Question 5

Compensation: Resp acidosis

Answer 5

Acute- HCO3 increased by 1mEq for every 10mmHg of CO2

Chronic- HCO3 increased by 3.5 mEq for every 10mmHg of CO2

Question 6

Compensation: Resp alkalosis

Answer 6

Acute- For every 10 drop in PCO2, 2mEq drop in HCO3

Chronic- For every 10mmHg drop in PCO2, there is 5mEq drop in HCO3

Question 7

Albumin correction

Answer 7

For every 1g/dL decrease in serum albumin, anion gap increases by 2.3mEq/L

Question 8

New MUDPPILES

Answer 8

Methanol- Osm gap
Uremia
DKA
Propylene Glycol
Pyroglutamic Acid
Isoniazid
Lactic Acidosis
Ethylene Glycol- Osm gap
Salicylates

Question 9

UAG

Answer 9

• we dump H+ in DCT with non-titratable acid (NH3)
• Kidneys work (GI loss), lots NH4, lots of Cl (urine anion gap will be negative)
• RTA: not dump NH4, not dump Cl, UAG is positive indicating tubules

Question 10

Type of RTA

Answer 10

Distal- Type 1
Proximal- Type 2
Type 4 (Aldosterone)

Question 11

Type 1 RTA

• findings
• cause

Answer 11

inability to acidify urine, urine pH >5.5 despite acidemia; Low K (renal Na wasting, secondary hyperaldo)

• assoc with renal stone
• Causes Autoimmune (SS, SLE, Hashimoto), primary hyperpara, VitD intox, Ampho, toluene
• Tx: give bicarb

Question 12

Type 2 RTA

• findings
• cause

Answer 12

• cannot reabsorb HCO3, sodium wasting, secondary hyperaldo; distal tubule overwhelmed, cannot reabsorb, urinary loss of HCO3
  
  • Low K; not as severe acidosis, HCO3 >15
• Tx: bicarb not helpful (cannot reabsorb), given diuretic, to contraction alk

Question 13

Type IV RTA

Answer 13

• aldosterone low or kidneys not response
  
  • serum K high
• Drugs, spironolactone, ACE, TMP, heparin, NSAIDs
• T2DM, HIV, Sickle Cell

Question 14

Definition AKI

Answer 14

rise of serum Cr > or = 0.3 within 48h or 1.5 times baseline within 7d or UOP <0.5mL/kg/h for 6h

Question 15

Pre-renal vs Renal values on labs

Answer 15

Pre-renal Renal
Urine Na <20 >40
FENa <1% >2%
FEUrea <35% >50%

Question 16

Hyponatremia:

1. Chronic
2. Pace of correction

Answer 16

1. > 48h
2. 4mWq in first 6-8h if nonsevere
   - severe- 10mEq in first 24h, avoid more than 18mEq in first 48h

Question 17

Hyponatremia:

1. U Na
2. U Osm

Answer 17

1. Hypovolemic <30, SIADH >30
2. U Osm >100 for both (greater than serum Osm in SIADH)
   - Uosm in hypovolemic improves to <100 with volume resuscitation

Question 18

Amount to correct Na in hypernatremia

Answer 18

0.5mEq/h or less

Question 19

TBW calculation and Free water deficit

Answer 19

TBW 0.6 weigh (in kg) for men or 0.5x weight for women

Current TBWx current Na/140= restored TBW

Question 20

Serum Osm calc

Answer 20

serum osm= 2xNa+ BUN/28+Glu/18

Question 21

DDx for Euvolemic, hypo-osmolar hyponatremia

Answer 21

SIADH (UNa high >30, U Osm high)
Primary adrenal insufficiency
Hypothyroidism
Drugs (HCTZ, ACE, SSRI)

Question 22

DDx for hypernatremia

Answer 22

Hypovolemic: Dehydrated
Hypertensive: Primary Hyperaldo (hypokalemic, met alk), ADH will normally keep Na in check
Euvolemic: DI (Central and nephrogenic)

Question 23

Body weight x 0.6
(Current Na/Desired Na)-1
xTBW= Free water deficit

Answer 23

Correct 50% in 24h, then remaining 50% over 1-2d

Question 24

Correction: Resp Acidosis

Answer 24

Acute: 10 change in PCO2, 1 change in bicarb
Chronic: 10 change in PCO2, 3 change in bicarb

Question 25

Correction: Resp Alk

Answer 25

Acute: 10 change in PCO2, 2 change in bicarb Chronic: 10 change in PCO2, 5 change in bicarb

Question 26

Correction: Met acidosis

Answer 26

Winter's formula

Question 27

Correction: Met alk

Answer 27

15 change in bicarb, 10 change in PCO2

Question 28

Hypothermia can induce: elect abnml

Answer 28

hypokalemia

Question 29

HyperCa EKG, sx

Answer 29

short QT -weak weakness

Question 30

Hypocalcemia EKG, sx

Answer 30

long QT | paraplegia, tetany (Chovstek, Trousseau)

Question 31

Compensation for Met Alk

Answer 31

pCO2=0.7(bicarb)+20 (+/-5)

Question 32

Met Alk | Thought Process

Answer 32

BP and intravasc volume. 1. BP low/normal and intravasc volume down but insterstitial volume up (Nephrotic syndrome, CHF, cirrhosis) 2. Low volume, no increase insterstitial volume. USE URINE CL- - Urine Cl- low- Saline responsive - High Urine Cl- (low K, low Mg, Barter, Gitelman) 3. Intravasc volume up, BP high - Conn's syndrome, hyperaldo

Question 33

FENA

Answer 33

ScrUna/(UcrSna)

Question 34

TTKG

Answer 34

UK/serumK

Question 35

HypoMg Sx, eKG

Answer 35

hyperreflexia, muscle fasic, tetany (same direction as Ca) | bradycardia, prolonged QT

Question 36

HyperMg sx and EKG

Answer 36

absent DTR, somnolence, flaccid quad, resp dysfunction | -Mg acts as CCB at high levels, prolonged PR, increased QRS, hypotension, bradycardia