Parenteral Nutrition Flashcards
1
Q
Synonyms for TPN?
A
Central Venous Nutrition
2
Q
Indications for pN
A
- Patient has failed EN with appropriate tube placement
- Severe acute pancreatitis
- Inaccessible Gi tract
- Short Bowel Syndrome (<200 cm)
3
Q
When may the GI tract become inaccessible?
A
- Paralytic ileus
- Mesenteric Ischemia
- Small bowel obstruction
- GI fistulas
4
Q
When can paralytic ileus occur?
A
- If EN is not provided when needed within the first 24 hours, causing tissue burns
- This means no peristalsis, can cause distension and potential ischemia
5
Q
When may EN be OK in GI fistula?
A
-When we can place to TF distal to the fistula
6
Q
When may Short bowel syndrome manifest?
A
- After multiple Gi surgeries, and may have to be on TPN
- Cannot absorb all the nutrients they need on only 200 cm
7
Q
What are the indications for TPN?
A
-The contraindications for EN
8
Q
What happens when we have high out-put EN drains?
A
- There is a build-up of fluids in the Gi tract which is not desirable
- PN may be indicated
9
Q
What are the two types of PN?
A
- Central Parenteral Nutrition
- Peripheral Parenteral Nutrition
10
Q
When is peripheral venous access used?
A
- Short term (72-96 hours)
- Small tube, has less capacity to deliver large volumes of nutrition
- Not indicated for severely malnourished
11
Q
What is a PICC line?
A
- Peripherally Inserted Central Catheter
- Will end at the same place as a central venous catheter
- No surgery required, and can be inserted at the bed-side
12
Q
(T/F) We can only infuse central solutions into a PICC
A
False, can also support peripheral solutions
13
Q
What is a CVC?
A
- Central Venous Catheter, terminating in the superior vena cava
- Long term
- Requires surgical insertion
14
Q
PPN osmolality restriction?
A
600-900 mOsm/L
- Small veins cannot dilute hypertonic solution the same as larger veins
- Risk of tissue burns and phlebitis
15
Q
PPN dextrose concentration restriction?
A
150-300 g/day or 5-10% final concentration by weight
16
Q
PPN AA concentration restriction?
A
-50-100 g/day or 3% final concentration by weight
17
Q
PPN fluid requirement?
A
2.5-3L of fluid, as the PPN solution must be diluted to avoid tissue burns
18
Q
When is PPNundesirable?
A
In patients with fluid restriction
- Renal, heart failure, head trauma
- PICC line may be indicated in these patients
19
Q
Contraindications to PPN?
A
- Significant malnutrition
- Severe metabolic stress
- Large nutrient or electrolyte needs
- Fluid restriction
- Prolonged PN (>2wks(
- Renal or liver dysfunction
20
Q
What is a strong vascular irritant? Why may this be an issue for someone with high electrolyte needs?
A
- K+
- May be too irritating to deliver peripherally
21
Q
(T/F) Reducing K+ should not preclude treatment to help prevent/manage re-feeding syndrome even though it is a vascular irritant
A
T
22
Q
List complications of PPN
A
- Phlebitis
- Venous thrombosis
- Thrombophlebitis
- Extravasation and chemical burns
- Occlusion
- Pain
23
Q
What does ASPEN recommend concerning removing and replacing PPN lines?
A
-Remove and replace no more than every 72-96 hours unless clinically indicated
24
Q
Wherever possible, we should ____
A
use CPN
25
When is CPN indicated?
For long-term access - > 7 days to years
26
What is a key factor concerning CPN?
It is hyperosmolar (1300-1800) and therefore needs to be diluted in the veins of high pressure to avoid tissue burns
27
Glucose content in CPN?
150-600 g
28
Can CPN be used in the fluid restricted patient?
Yes
29
Which vein is catheterized in CPN?
- Subclavian or jugular vein, for termination in the superior vena cava
- 2-3 cm in diameter, 7 cm flow and 2L/min flow rate
30
Which medications may be used to reduce complications in PN?
-Hydrocortisone and heparin
31
How will heparin help?
- Reduce phlebitis
| - Will stimulate LPL which will help clear fat from vein, preserve the longevity of the catheter and prevent clotting
32
How will hydrocortisone help?
-Decrease irritation to the vein, alleviating phlebitis
33
What is a disadvantage of the high flow rate of CPN?
- Anything diffused into the body through CPN will reach the body quickly
- i.e. if there is a bacterial infection, it will be quickly dispersed into the body
- Less of a risk is posed peripherally
34
What are possible complications to PN?
- Sepsis
- Embolism
- Pneumothorax
35
What is a pneumothorax?
- A collapsed lung
- Occurs when air leaks into the space between the ling and chest wall
- We could accidentally feed into the pleural space, causing an infection and a pleural effusion
36
Your patient presents to the ER with intractable vomiting and is not responding to anti-nausea meds. How do you feed this patient?
-PN, likely PPN if short term
37
What is the most common form of long-term parenteral access?
CVC
38
What is the compostions of PN formulations?
- CHO (dextrose)
- IFE
- Proteins (Crystalline AA)
- Additives (Vitamins, Minerals and Trace elements)
39
What is IFE?
Lipid emulsified in injectable water with egg phospholipid
40
Consideration about infusion of CHO in PN?
Carbohydrates are hydrophilic, and will attract water
41
Energy density of dextrose CHO?
3.4 kcal/g
42
Which stock concentrations are CHO solutions available in?
2.5-70%
43
Acidity of CHO solutions?
pH of 3.5-6.5
44
What % of dextrose will be administered the centra vein? Why not peripherally?
- Solutions >10%
| - Risk of thrombophlebitis, as there is a large amount of osmolality
45
Maximum tolerance for clearance CHO solution?
- Less than 4-5 mg/kg/min
- Healthy people can typically tolerate 15 g/kg/day
- Use 3 mg/kg/min **
46
What is often included in the IVFE formulation?
- Egg yolk, phospholipids, vitamin K and sodium hydroxide
| - 100% soybean oils, or 50:50 soybean and safflower oils
47
10% IVFE?
- 1.1 kcal/ml or 11 kcal/g
- 10 g of lipid in 100 ml of solution
- Vessel used to deliver the propofol sedative/anaesthetic
- Caution on overfeeding
48
20% IVFE?
- 2 kcal/ml or 10 kcal.g
- 20 g of lipid in 100 ml of solution
- Most commonly used
49
What is found in the Intralipid IVFE solution?
- 20% soybean oil
- 1.2% Egg Yolk Phospholipid
- 2.25% Glycerine
- Water for Injective
- NaOH added to adjust the final pH
- pH range from 6-8.9
50
What is found in the SMOFlipid IVFE solution?
- 30% Soybean oil
- 30% MCT oil
- 25% Olive Oil
- 15% Fish Oil
51
When may the pH of 6 of intralipid be sub-opitmal?
When mixing into the admixture (dextrose and AA), which may cause destabilization of the other macronutrients
52
What is the rationale behind the compostion of the SMOFlipid?
- Fish oil which contains anti-inflammatory omega-3 fatty acids, providing EPA and DHA
- Soybean (omega-6) and olive oil (omega-9) to prevent EFAD and MUFA
- MCT oil which will provide a readily available source of Energy
53
_____ is how propofol is delivered in the ICU, in a ____ solution
Intralipid
| 10%
54
What is propofol?
A lipid-based intravenous anesthetic sedative energy, where the lipid content is the same as the 10% fat emulsion
55
How many kcal/ml of propofol?
1.1 kcal/ml
56
Potential adverse effects if we overfeed and forget to calculate energy/fat from propofol??
- Decreased lipid clearance
- Hyper TG
- Overfeeding
57
What is the max IVFE infusion rate?
2.5 g/kg/day
58
To prevent EFAD, what may be the lowest IVFE infusion rate?
0.4-1.0 g/kg/day
59
Max IVFE infusion rate for the critically-ill or immuno-compromised?
1.- g/kg/day
60
What does ASPEN suggest concerning EFAD deficiency between weeks 1-3 if there is no source in the PN?
-Deliver 250 ml of 20% or 500 ml of 10% soy-based IVFE over 8-10h twice/week to prevent deficiency
61
When may we need to increase biweekly deliveries of IVFE to avoid EFAD?
- If we are using SMOFlipid
| - As there is less omega-3 and 6 fatty acids
62
What is the minimum frequency of providing the lipid emulsion?
twice a week
63
What is the recommended hand time for a prepared solution?TNA?
- 12 hour, as the open container has mixed-in the sterile contents
- 24 hour for TNA, as we can shake the bag, break the membrane right away
64
What is the clinical presentation of EFA deficiency?
- Xerosos (Eryhtema Craquele: Steatosisi)
| - Can also be caused by deficiencies of retinol/RBP and zinc
65
What is the AA PN solution composed of? Energy content? % concentrations?
- Mixture of essential and non-essential amino acids
- 4 kcal/g
- 8.5%, 10% and 15%
66
What % AA solutions available for PPN?
3.5-5.5%
67
What % AA solutions available for CPN?
8.5-20%
68
What is the common AA solution at the MUHC?
- Travasol
- 10% stock solution
- No electrolytes
69
What is Aminosyn?
-AA solution, available at 8.5 and 10% stock solutions
70
Calcium intake in PN?
10-15 mmol
71
Magnesium intake in PN?
8-20 mmol
72
Phosphate intake in PN?
20-40 mmol/kg
73
Sodium intake in PN?
1-2 mmol/kg
74
Chloride intake in PN?
Enough to maintain acid-base balance
75
Bicarbonate intake in PN?
To maintain acid base balance
76
When we see 12 h and 24 h infusion rates, what can we infer?
- That the admixture and the IVFE is administered separately
| - "Piggy-back" method through a Y tube
77
(T/F) Only TNA (or 3-in-1) can be used in central parenteral nutriton
F
Can be administered both in CPN and PPN
78
Pros of 2-in-1 mixture?
- More stable solution
- Less risk of bacterial contamination
- Longer hang times
79
Cons of 2-in-1 mixture?
- Faster infusion ate of IVFE can lead to hypertriglyceridemia
- More nursing time is needed
- Additional IV tubing for lipids is needed
80
What is TNA?
The combination fo dextrose, amino acids, and IVFE with electrolytes, vitamins, minerals, trace elements and sterile water for injection in 1 IV bag
81
Pros of TNA?
- Decreased cost
- Decreased nursing time
- Less manipulation, thus less infections
- Fat clears better when administered >12 hour s
82
Cons of TNA?
- Requires larger pore-size filter (1.2 microns) --> IVFE instability risk
- Higher incidence of medication incompatibility with IVFE
83
Osmolality of CHO?
5 x g of CHO
84
Osmolality of protein?
10 x g of protein
85
Osmolality of electrolytes, vitamins and minerals?
300-300 mOsm/L
86
Osmolality of fat?
IV fat is isotonic at 300 mOsm/L
87
Short-term PN complication?
- HyperG
- Refeeding syndrome
- Azotemia
88
Long-term PN complications?
- Vascular access sepsis
- HyperTG
- Hepatobiliary complications
- Metabolic bone disease
89
Can short and long-term complications occur at any time?
Yes
90
What may cause hyperTG?
Dextrose overfeeding or rapid IVFE infusion
91
Hepatobiliary complications which may arise in PN?
- Steatosis
- Cholestasis
- Gallstones
92
What is the most common PN-associated complication?
- Hyperglycemia
| - Due to stress in critically ill and CHO overfeeding
93
How should dextrose be initiated for the first 24-hours?
150-200 g/day
94
How should dextrose be initiated if patient has a low BMI, diabetes or risk of RF syndrome?
100 g/day
95
What is the Max CHO rate?
- 4-5 mg/kg/min or 20-25 kcal/kg/day
| - Use 3 mg/g/day in critically-ill
96
How often should we monitor blood glucose? What is the goal?
- Every 6-8 h upon initiation
| - 8.3-10 mmol/L
97
Why is the glucose target range more liberal?
Recall that with PN, we are in a fed state ... which means we will not see "normal" BG until feeds are stopped or we are administering insulon
-Also due to the metabolically stressed state
98
What must be controlled prior to advancing feeds?
- All complications
| - Most commonly hyperglycemia
99
Insulin therapy?
0.5-0.1 units per g dectrose
100
Insulin therapy if already hyperglycemia/
0.15-0.3 unites per g dextrose
101
What rapid infusion rate could trigger hyperTG?
>0.11 g/kg/hour
| --> Recall our max infusion rate of 1 g/kg/day
102
What may hyperTG cause?
- Pulmonary complications
| - Increase risk of pancreatitis if TG >11.30 mmol/L
103
Goal TG? Why is it liberalized?
<4.52 mmol/L
- As we are in fed state most often
- This will differ if we are feeding TNA or 2-in-1
104
How may HyperTG be managed?
- Reducing dose, or increasing infusion time
| - Use <30% pf E or 1g/kg/day
105
What is azotemia?
Elevation of BUN and creatinine levels
106
What may azotemia result from?
- Excessive protein administration
- Dehydration
- Inadequate non-protein energy
- Impaired ability to clear urea (patients with hepatic and renal disease)
107
When may patients benefit from reducing AA and the use of hepatic-disease formulations (BCAAs)?
- Those with Azotemia
| - Not common in ICU
108
What needs to be monitored in PN?
```
-Fluid intake
and output
-Weight
-Body temperature
-Glucose tolerance
-Electrolytes
-Hepatic function (LFT's)
```
109
How can fluid outputs and inputs be monitored?
- IV fluids from all sources, oral intake, flushes
| - Urine, fecal losses, drainage, nausea and vomiting
110
How often should weight be monitored?
Twice a week
111
How often should body temp be monitored? When should MD be notified? Nutrition implications?
- q8h
- When temp >38.5
- Increased fluid and energy needs, less clearance of TGs and CHOs
112
How often should BG be monitored?
-q6h, more if hyperG
113
How often should electrolytes be monitored?
- 1x/day
| - If stable, progress to once every 1-2 wks
114
How can we monitor protein status in PN?
- Visceral proteins (albumin, pre-albumin, transferrin)
- CRO
- Nitrogen balance (+/-2)
115
When is nitrogen balance unreliable?
- Kidney (dialysate)and hepatic disease
| - Excessive trauma, burns, oozing wounds
