Transcript No Slide Title

Micronutrient Requirements
and Deficiencies
Douglas L. Seidner, MD, FACG
The Cleveland Clinic
Digestive Disease Center
The ASPEN Nutrition Support Core Curriculum 2007
The ASPEN Nutrition Support Core Curriculum 2007
Composition of Body Fluids
Na+
K+
Cl-
HCO3-
Plasma
135-150
3.5-5
98-106
22-30
Gastric
10-150
4-12
120-160 0
Bile
120-170
3-12
80-120
30-40
Sml Int
80-150
2-8
70-130
20-40
Diarrhea
25-130
10-60
20-90
20-50
Sodium (Na)
• Total body Na is 40 mEq/kg (280 mEq in a
70 kg patient)
• One third fixed in bone
• Two thirds exchangeable (mostly
extracellular)
• Normal daily adult Na requirement is 1-2
mEq/kg
• Renal Na reabsorption efficient (< 1mEq/L)
Sodium (Na)
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Extracellular ion
Usual dose 100-150 mEq/d
This approximates 0.45%NS
Added as acetate or chloride salt
Sodium Deficit =
0.6 x (wt in kg) x (140 – Na) + (140) x (Vol
deficit in L)
Hyponatremia
• Primary – due to sodium loss
• Secondary – due to excess of free
water (most common)
Primary Hyponatremia
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GI losses
Fistula drainage
Use of diuretics
Adrenal insufficiency
Secondary Hyponatremia
• Infusion of hypotonic solutions
• Excess ingestion of free water
• Increased reabsorption of free water
(ADH)
Symptomatic Hyponatremia
• Chronic hyponatremia usually
asymptomatic until Na < 110-120
mEq/L
• Acute hyponatremia can become
symptomatic if Na < 120-130 mEq/L
Symptoms of Hyponatremia
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Headaches
Confusion
Delirium
Seizures
Coma
Acute Hypotonic Hyponatremia
(acute water intoxication <24hrs)
• < 125 mEq/L – headache, apathy,
nausea, confusion
• < 115 mEq/L – seizures, coma
The ASPEN Nutrition Support Core Curriculum 2007
The ASPEN Nutrition Support Core Curriculum 2007
The ASPEN Nutrition Support Core Curriculum 2007
Estimating Sodium Requirement to
Correct Serum Deficit
• mEq of Na needed = (desired Nameasured serum Na) x .6 x body
wt.(kg)
• Give no more than ½ the first day
• Rapid correction (>12mEq/day) can
cause osmotic myelinolysis
Hypernatremia
Etiology
• Excessive water loss exceeds
sodium loss
or
• Excesive sodium intake exceeds
water intake
The ASPEN Nutrition Support Core Curriculum 2007
Hypernatremia
Symptoms
• Symptoms if Na>160 acutely or >170
chronically
• Symptoms are neurologic
lethargy and confusion, twitching,
grand mal seizures, stupor and
coma
Treatment of Hypernatremia
Calculation of Water Deficit (70 kg man
with a serum Na of 160mEq/L)
• Water deficit (L) = 0.60 x wt in kg x
[(serum Na/140) – 1]
• Water deficit (L) = 0.60 x 70 x
[(160/140) – 1] = 5.88 L
Potassium (K)
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Intracellular cation
Usual dose is 60-120 mEq/d for PN patient
Added as acetate or chloride salt
Total body potassium falls ~370 mEq for
each 1 mEq/L fall in measured serum K
Potassium (K)
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Total body K is 50-55 mEq/kg
98% is intracellular
Normal daily adult intake is 1 mEq/kg
Kidneys can decrease K excretion to
no lower than 10 mEq/L
Potassium
• Hypokalemia can cause weakness
and if severe psychoses and
paralysis
• Hyperkalemia is more dangerous and
can cause EKG changes,
bradycardia, asystole, and vent. fib.
Guidelines for Potassium Therapy
• For normal adults 40 – 60 mEq/day
are given as IV replacement therapy
• For K between 3.0 – 3.5mEq/L, 100
mEq will raise the serum K by 1
mEq/L
• For K less than 3.0, 200 mEq will
raise the serum K by 1 mEq/L
• Do not exceed infusion rates of
20mEq/hour and recheck K after
40mEq
Hypokalemia and the ECG
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Low voltage
Flattened or inverted T waves
Prominent U waves
Depressed ST segments
Widened QRS complex (K<2.0)
Hyperkalemia and the ECG
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Flattenend P waves
Widened QRS complexes
Heart block, atrial asystole
Sine wave, V Fib
Electrocardiogram
Hyperkalemia vs Acute MI
Hyperkalemia
Acute MI
Hyperkalemia – T wave is tall, narrow and symmetrical
Acute MI – T wave is tall but broad-based and asymmetrical
Treatment of Hyperkalemia
• 10 units of Insulin + 25 gm of glucose
• 45 mEq NaHCO3
• 25 gm cation exchange resin in 20%
sorbitol solution orally q. 4-6 h or;
• 50 gm cation exchange resin in 1-200
ml 35% sorbitol by enema q 4 h
CHLORIDE
• Extracellular anion
• Osmotic pressure and acid base balance
• Chloride released as HCl as by-product of
amino acid metabolism
• Acetate salts used to prevent
hyperchloremic acidosis
• Administer as potassium or sodium salt
Chloride deficit (mM) =
0.5 x body wt (kg) – (Cl-NORMAL _ Cl-MEASURED)
ACETATE
• Amino acid metabolism may produce
metabolic acidosis resulting in ↑
bicarbonate requirements
• Bicarbonate changes pH; insoluble
precipitate forms with calcium and
magnesium (never add bicarbonate
to PN solutions )
• Acetate salts are converted to
bicarbonate in the liver
• Functions as systemic alkalinizers
• Use serum CO2 levels as a guide
CALCIUM
• Extracellular cation
• Usual dose 9-22 mEq/d
• Calcium gluconate yields 4.65 mEq/gram
Corrected calcium concentration:
Total Ca2+CORRECTED(mg/dl) =
Total Ca2+MEASURED(mg/dl) + ([4 – albumin
(g/dl)] x 0.8)
*ionized calcium level when in doubt
PHOSPHORUS
• Intracellular anion
• Usual dose 15-30 mM/d
• 1 mEq potassium phosphate = 0.68 mM
phosphate or 21 mg elemental
phosphorus
• 1 mEq sodium phosphate = 0.75 mM
phosphate or 23 mg elemental
phosphorus
MAGNESIUM
• Cation (primarily intracellular)
• Usual dose 8-24 mEq/d
• Magnesium sulfate yields 8.12 mEq/gram
Corrected magnesium concentration:
Mg CORRECTED = Mg + 0.005[4.0-albumin (g/dl)]
Composition of Common
Electrolyte Solutions
Solution
Na
K
Ca
Cl
HCO3 mOsm
precursor
Ringer’s
130
Saline
154
4
3
109
154
D/5/W
D/5/0.45% 77
NaCl
“
77
+ 20 KCl
28
280
308
250
20
77
405
77
445
ELECTROLYTE REQUIREMENTS
Sodium
Potassium
Chloride
Acetate
Calcium
Magnesium
Phosphorus
1-2 mEq/kg/d
1-2 mEq/kg/d
As needed for acid-base balance
As needed for acid-base balance
11-15 mEq/d
8-20 mEq/d
20-40 mEq/d
Guidelines for the use of parenteral and enteral nutrition in adult and pediatric patients. JPEN
2002;26S:22SA
Daily IV Electrolyte
Recommendations
• Calcium 4.5-22
mEq
• Phosphate 15-30
mMol
• Magnesium 8-24
mEq
• Sodium 60-150
mEq
• Chloride 100-150
mEq
• Acetate 10-150
mEq/Liter
• Potassium 60-120
mEq
References
• Langley G. “Fluid, Electrolyte, and AcidBase Disorders.” In Gottschlich MM,
DeLegge MH, Mattox T, Mueller C,
Worthington, Eds. The ASPEN Nutrition
Spport Core Curriculum: A Case-Based
Approach-The Adult Patient. ASPEN,
Silver Spring, MD, 2007, pp 104-128
• “Estimating Nutritional Requirements.”
The Cleveland Clinic Foundation Nutrition
Support Handbook, Eds Parekh N,
DeChicco R. 2004 pp 34-60.
Thank you