Lecture 5: Nutrition, Fluids, and Electrolyte Therapy Flashcards

1
Q

What should we not base our nutrition assessment solely on?

A

Weight

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What goes into a nutrition assessment?

A
  • BMI
  • Unintentional weight change
  • Changes in PO intake
  • Severity of illness
  • IBW
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the criteria to diagnose malnutrition?

ASPEN Criteria

A
  • Insufficient caloric intake (energy intake)
  • Wt loss
  • Loss of muscle mass
  • Loss of subcutaneous fat (Body Fat)
  • Localized or generalized fluid accumulation masking wt loss (Fluid accumulation)
  • Diminished functional status (Grip strength)

At least 2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What can long-term overfeeding result in?

A
  • Hepatic steatosis
  • Ureagenesis
  • Immunosuppression (esp w/ liquids)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What equations are used to determine nutrition requirements?

A
  • Harris Benedict
  • Mifflin-St Jeor
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Quick rule of thumb for estimating caloric needs and protein needs based on IBW

A
  • Cal: 25-30/kg/d
  • Protein: 1.2g/kg/d

Burn pts may require more protein, up to 2g/kg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the preferred method of feeding?

A

PO

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

When do we start enteral or parenteral feeding?

A

7-10d of no oral intake and if its going to be in for at least 5 days.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How does enteral nutrition work?

A

Direct entry into GI system at stomach or small intestine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

CIs to enteral nutrition

A
  • GI hemorrhage
  • Peritonitis
  • Severe ileus
  • Bowel obstruction distal to access site
  • Intestinal ischemia
  • Malabsorptive disorders with high volume diarrhea
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How do we start enteral nutrition?

A
  • Low rate, tapering up after 24-48h
  • Monitoring for N/V/D/C/abd pain
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How are macronutrients presented in parenteral nutrition?

A
  • Carbs: Dextrose (50%-60%)
  • Protein: Crystalline amino acids (15%-25%)
  • Lipids: Polyunsaturated long-chain triglycerides like soybean oil (20%-25%)

parenteral has the highest risk.

alphabetically in order of highest to lowest proportion CLP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is refeeding syndrome?

A

Electrolyte abnormalities that occur during reinstitution of carbs to a starved patient

Phosphate, Mg, and K depletion may occur

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the typical breakdown of macronutrients in parenteral nutrition?

A
  • Carbs: 50-60%
  • Proteins: 15-25%
  • Lipids: 20-25%
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What kind of access does parenteral nutrition require?

A

Central venous access due to its hyperosmolar nature.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How often do we recheck labs in pts on TPN?

A
  • Glucose: every few hrs
  • BMP: Q8-12h
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the general breakdown of fluid in the body?

A
  • ICF: 2/3
  • ECF: 1/3

Within ECF: 75% is interstitial, 25% is intravascular.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How do you approximate TBW (total body water)?

A

60% of body weight in males

50% for a female

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Example distribution of TBW

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Normal minimal obligatory water intake

21
Q

Where is most fluid loss through?

22
Q

What requires increased water intake? (7 conditions)

A
  • Fever
  • Sweating
  • Burns
  • Tachypnea
  • Surgical drains
  • Polyuria
  • Ongoing GI losses
  • 100-150 mL/d for every degree of body temp above 37C
23
Q

4 main ways we lose water from our body

A
  1. Urine: 500 mL
  2. Skin: 500 mL
  3. Respiratory tract: 400 mL
  4. Stool: 200 mL
24
Q

How do we estimate water requirements?

A
  • 35 mL/kg/d = 35x70 = 2450 mL/d
25
Na requirements daily
* 1-3 meqs/kg/d * **0.45% saline contains 77 meq NaCl/L**
26
K requirements daily
* **1 meq/kg/d** (50-100 daily) * Osmotically as active as sodium, so adding 40 mEq to 0.45% saline creates 3/4 isotonic saline. * Commonly added as 20meq/L | Oral is most preferred
27
Why do we only infuse potassium at 10 meq/hr?
Rapid administration causes a burning sensation
28
How do we estimate hypokalemia?
1 mmol/L below normal => total deficit of 200-400 mmol
29
How do we calcuate the potassium deficit and correct it?
* Deficit in mmol = (normal K lower limit - measured K) x BW in kg x 0.4 * **10 mEq of KCl** raises serum by abt **0.13 mEq for normal kidneys.** | 1 mmol = 1 mEq
30
Average dosing to tx hypokalemia
40 to 100 mmol/d
31
What are the 3 primary mechanisms we utilize to treat hyperkalemia?
1. Membrane stabilizer: calcium gluconate 2. Redestribution: insulin + B2 agonist (albuterol) 3. Removal: Kayexalate or hemodialysis
32
Why do we want to make sure glucose is normal and how?
* If glucose is low, protein and body fat will get consumed. (**Protein-sparing effect**) * We need about **100-200g/d**
33
What are colloid solutions? (2)
* Large molecules that **DO NOT PASS** through membranes * When infused, they remain in the intravascular compartment and expand intravascular volume by drawing fluid from extravascular spaces. | Albumin is the most common?
34
What are crystalloids? (3)
* Small molecules that **flow between cell membranes** * Increase fluid volume in both intra and extravascular spaces. * Subdivided into isotonic/hypotonic/hypertonic
35
What is the danger with infusing sodium too fast?
Central pontine myelinolysis can occur
36
What are the isotonic crystalloids? (4)
* NS (0.9%) * LR's * D5W (5% dextrose in water) * Ringer's acetate solution
37
What is in NS? (2)
* 154 meq of Na * 154 meq of Cl
38
What is in LR/hartmann solution? (5)
* 130 meq of Na+ * 4 meq of K+ * 3 meq of Ca+ * 109 meq of Cl- * 28 meq of HCO3- | Most physiologically adaptable due to similarity to body composition.
39
When is LR typically used? (5)
* Burn injuries * GI tract losses * Fistula drainage * Fluid losses due to burn/trauma * Acute blood loss or hypovolemia d/t 3rd spacing
40
What is the concern with using LR? (3)
* LR **cannot be used in someone with liver dz**, or it will make bicarb * Caution in **severe renal impairment** d/t K * Do not give in **someone with pH > 7.5**
41
What happens when D5W is metabolized?
Hypotonia, causing fluid shift inward to cells.
42
How many calories is D5W?
170 cal
43
What are the primary options in treating hypovolemia via fluids? (2)
Volume expansion: NS or LR | We want intravascular volume expansion
44
How do we treat dehydration/hyperosmolarity? (Not hypovolemia)
**Free water replacement**, aka D5W or 0.45% saline
45
In post-op pts, how do we manage fluids?
**NS is preferred** because narcotics can stimulate SIADH.
46
Why does NS cause volume expansion? (3)
* Free water gets distributed * Na stays outside of cells * NS essentially has no free water.
47
What is the 4 2 1 rule of peds for maintenance fluids?
* First 10kg = 4 cc/kg/hr * Second 10kg = 2 cc/kg/hr * 1cc/kg/hr after | Maintenance fluids
48
What is the IVF rate for an adult?
wt (kg) + 40 per hour.