7 .

HCO3
pH = 6.1 + log ____________
.03 pCO2

50

HCO3 mEq/L

7 .4

pCO2
pH = 7.62 - log ____________
HCO3
H+ (nEq/L) =

40

7 .5

24 pCO2
____________
HCO3

7 .3

pH
= 7.0 7.1 7.2 7.3 7.4 7.5 7.6 7.7 7.8
H+ nM = 100 79 63 50 40 32 25 20 16
0.1 pH = 80% H+
H+ ~ (7.8 - pH) x 100

7 .2
30
7 .1

20

10

20

30

40

Metabolic acidosis
Metabolic alkalosis

PaCO2
PaCO2

1.25 mmHg per mEq/L HCO3

.75 mmHg per mEq/L HCO3

( 5 mmHg)
( 5 mmHg)

Acute Resp acidosis

Chronic Resp acidosis

HCO3
HCO3

1 mEq/L per 10 mmHg pCO2

4 mEq/L per 10 mmHg pCO2

( 3 mEq/L)
( 4 mEq/L)

Acute Resp alkalosis

Chronic Resp alkalosis

HCO3
HCO3

2 mEq/L per 10 mmHg pCO2

4 mEq/L per 10 mmHg pCO2

( 3 mEq/L)
( 3 mEq/L)

70

90

50
pCO2 mmHg

60

80

GFR
Normal

FRACTIONAL EXCRETIONS
= 100 - 125 ml/min/1.73 m2 (Male) 85 - 105 (Female)

FENa

Ucreat (mg/dL)
Uvolume (ml/day)
Ucreat (mg/day)
Measured = ____________ x _______________ = ____________ x .07
Pcreat (mg/dL)
1440 min/ 1 day
Pcreat (mg/dl)
(ml/min)
Cockroft - Gault
Cockroft-Gault Estimate =
(ml/min)

140 - age x __________

weight (kg)
__________
(x.85 Female)
Pcreat
72

MDRD Estimate = 170 x P creat

-.999

x Age

-.176

= % filtered Na load excreted.

U
U
= __
Na __ creat
P
P
< 1% in normal urine, and prerenal azotemia
FEurea
< 35% = prerenal, not altered by diuretics
FEuric acid < 10% = prerenal, not altered by diuretics

x (.762 if Female) x (1.18 if Black) x BUN

-.17

+.318

x Albumin

HYPONATREMIA
UNa

< 10 mEq/L = ECF volume (CHF, cirrhosis, nephrotic)

ECF volume
> 10

H2O gain = .6 x [wt,kg] - .6 x [wt,kg] x osm/290

UNa + UK
CH O = Uvolume - __________
(L/day)
2
PNa

= Normal ECF volume

RATS = Renal, Adrenal, or Thyroid insufficiency or SIADH
SIADH = CNS, pulmonary, or psychiatric disorder, drugs,
nausea, ADH-secreting tumors

H2O load: 20 ml/kg; Nml = 80 % excreted in 4 hrs

& Uosm < 100
CORRECTIONS TO PLASMA VALUES

OLIGURIA = <500 ml/day = <20 ml/hour

Prerenal
Azotemia
Uosm, mOsm/Kg
UNa, mEq/L
FENa
Sediment

> 400
< 20
< 1%
normal

ATN
< 400
> 40
> 2%
muddy casts, RTE
and bubble cells

Acute
Acute
Obstruction Glomerulonephritis
variable
variable
variable
normal

> 400
< 30
< 1%
RBC casts,
Dysmorphic RBCs

HYPOKALEMIA
intake
shift into cells: glucose, insulin, agonists, alkalosis or HCO3 Rx
loss - Renal: diuretics; high flow; aldo, RTA
GI: emesis, diarrhea, laxatives
HYPERKALEMIA
Artifact: hemolysis, WBC > 50,000, tourniquet + exercise, platelets
intake: hemolysis, rhabdomyolysis, transfusion, salt substitutes
shift out of cells: acidosis, 0 insulin, dig toxicity, arginine
blockers, hyperalimentation
renal excretion: GFR, aldo, tubular defects, drugs

Na

1.35 - 2.4 mEq/L per 100 mg% glucose

No artifact with lipemia or paraproteins if Na measured
by ion-specific electrode on undiluted plasma

Calcium

.8 mg% per gm%

albumin
.16 mg% per gm% globulins
.12 mg% per .1
pH

.6 mEq/L
.6 mEq/L
.15 mEq/L

per 0.1 pH
} variable, depends
per 10 mOsm }
on cause
per 100 x 109 platelets /L

TTKG
= transtubular K gradient at CCD
= 4-14, varies with diet
U K UOsm
=
U
P
With hypokalemia
<2
= GI loss
>4
= Renal loss; excess aldo
nml

With hyperkalemia
<6
= renal: aldo effect
>10 = non-renal hyperkalemia, normal aldo effect

NORMAL ABGs
Arterial
pH
7.40 .02
pCO2 mmHg 40 2
pO2 mmHg

90 10

O2 sat, %
>95%
HCO3 mEq/L 24 2

REMOVAL OF TOXINS
Mixed venous
7.36 .02
46 .02
38 5
70 10%
24 2

Consider hemodialysis (HD) or hemoperfusion (HP)

at these levels: (Source: Handbook of Dialysis,
Daugirdas and Ing, Little Brown and Co., Boston,1988)
Drug
Phenobarbital
Glutethimide
Methaqualone
Salicylates
Theophylline
Lithium
Methanol

Serum level (mg/dl)

10
4
4
80
30-40
2.5-3.5
100

METABOLIC ACIDOSIS

Treatment choice
HD or HP
HP
HP
HD
HP
HD
HD

mean
1-7
10-20
6-12
3.5-5.5

METABOLIC ALKALOSIS

Plasma anion gap = Na - [Cl + HCO3] Nml = 12 2

Urine Cl < 10 mEq/L = saline responsive = emesis, diuretics, posthypercapnea

> 10
= mineralocorticoids, alkali intake, K depletion

< 12 = diarrhea, RTA, CaCl2 or other acids

> 15 = MUDPALES = Methanol, Uremia, Diabetic
ketoacidosis, Paraldehyde, Alcoholic
ketoacidosis, Lactic acidosis, Ethylene
glycol, Salicylates

RENAL TUBULAR ACIDOSIS

Proximal

Urine anion gap = UNa + UK -UCl

GI HCO3 Loss

HEMODYNAMICS
systolic
diastolic
RA,
mmHg
RV,
mmHg
15-25
0-8
PA,
mmHg
15-25
8-15
PCWP, mmHg
CO,
L/min
MAP = diast. BP + 1/3 [syst. - diast.]
SVR = 80 x [MAP - CVP]/CO (L/min)
= Nml 900- 1200 dyne/sec/cm2

Renal HCO3 Loss

Gap

Gap

NH4+ present
No NH4+ present
UNH + = UCl [UNa + UK] + 80 mEq /L
4
Osmolar gap = measured osm - calculated osm; nml = 10
= measured osm - (1.87 Na + BUN/2.8 + glucose/18 + 9)
> 10 = ethanol (4.4 mg%/mOsm/L), methanol (3), ethylene
glycol (6), isopropanol (5.7), sorbitol, mannitol, X-Ray dye

Prevalence
Plasma K
Urine pH
Urine NH4+
Defect

Rare
Low
<6
Normal

Rx

High capacity
HCO3 transport
Diuretic

Examples

Acetazolamide

Classical
Distal
Rare
Low
>6
Low
H Pump
HCO3
Amphotericin

Type 4
Very common
High
<6
Low

Hyperkalemic
Distal
Common
High
variable
Low

NH3 generation
aldo effect

Distal Na
Transport

Diuretic

HCO3
Obstruction

Diabetes

Kidney Kard
Please see full Prescribing Information, including boxed WARNING for MICARDIS Tablets.
MC-11292

ADEQUACY OF DIALYSIS

THE 5 STAGES OF CHRONIC KIDNEY DISEASE (CKD) NKF GUIDELINES

STAGE

Hemodialysis
KT/V per Rx
% reduction urea
Protein intake

Unacceptable

DOQI Goal

<1
< 60%

> 1.2
> 65%
> 1.2gm/kg/day

2
3

> 2.0
> 60
> 1.2 -1.3 gm/kg/day

4
5

Peritoneal dialysis
KT/V per week
< 1.6
Creatinine clearance < 40 liters/week
Protein intake

PLASMA
Common units

NORMAL VALUES

DESCRIPTION

BUN
Calcium
Ca-ionized
Creatinine
Cystatin C
Glucose
K
Mg
Na
NH3+NH4
Osmolality

8-25
8.5-10.5

mg%
mg%

.6-1.5
.53-.95
70-110
3.5-5
1.8-3
135-145

mg%
mg/L
mg%
mEq/L
mg%
mEq/L

280-296

Phosphate
Urate

2.6-4.5
3.6-8.5
2.3-6.6

Sl units

At risk
Kidney damage with
normal or GFR
Kidney damage with
mild GFR

Mark Graber, M.D. 6th Edition 2006

VA Medical Center, Northport, NY 11768
mark.graber@med.va.gov

> 90

INTERVENTIONS
Screening, reduce cardiovascular and CKD risks
Above, + pursue early diagnosis and treatment. Treat comorbid
conditions. Reduce cardiovascular risk. Slow CKD progression

60-89

Above + estimate and slow progression of CKD.

Moderate GFR

30-59

Treat anemia, improve nutrition, manage bone disease, manage

symptomatic neuropathy, manage biochemical abnormalities
(acidosis, potassium disturbances)

Severe GFR

15-29

Prepare for renal replacement therapy

Kidney failure

15 or
dialysis

Replacement therapy if uremia present. Manage PD or

hemodialysis access, ensure dialysis adequacy

Conversion
Factor

URINE
units = /day

2.9-8.9
2.1-2.6
1.14-1.3
53-133

mM urea
mM
mM
uM

0.357
0.25

160 mg/gm diet protein

<300 mg

88.4

15-20 mg/kg (M); 10-15 (F)

mM
mM
mM
mM
uM
mmol/kg

0.0555
1
0.411
1

mOsm/kg

3.9-6.1
3.5-5
0.8-1.2
135-145
12-55
280-296

mg%
mg% (M)
mg% (F)

.84-1.45
214-506
137-393

mM
uM
uM

0.323
59.5
59.5

Kidney Kard

GFR

Division of Nephrology, HSC 15-020

SUNY at Stony Brook, NY 11794

= intake (.5-1 mEq/kg)

If Mg depleted: < 1 mEq
=intake (.5-2 mEq/kg)
0.5-1 mEq/kg
If Posm low: < 100 mOsm/kg
If Posm high: > 700 mOsm/kg
about 1 gm
< 700 mg
< 700 mg