Comprehensive Guide to Parenteral Nutrition: Types, Goals, and Risks

What is parenteral nutrition?

Nutrients administered directly into the blood

What are the goals of parenteral nutrition?

Improve nutritional status; establish positive nitrogen balance; maintain muscle mass and promote weight maintenance or gain; enhance healing process

What should be assessed before initiating parenteral nutrition?

Allergies; height, weight, BMI, current nutritional status; medical history; risk factors for refeeding syndrome

What labs should be obtained before initiating parenteral nutrition?

CBC, CMP including BUN/creatinine and LFTs; iron; total iron binding capacity; lipid panel; triglycerides; glucose; albumin; pre-albumin

What should be verified before initiating parenteral nutrition?

CVC vascular access placement

What should be provided before initiating parenteral nutrition?

Patient education

What is PPN?

Peripheral parenteral nutrition

What is TPN?

Total parenteral nutrition

What is PPN indicated for?

Short-term nutrition support (7-10 days); patients whose protein and caloric requirements are not too high; supplementing inadequate PO intake

What is a limitation of PPN?

It is a nutritionally incomplete solution

What is TPN indicated for?

Long-term nutritional support; high protein and calorie requirements; inability to ingest, digest, or absorb nutrients through the GI tract

What are examples of situations requiring TPN?

Complicated abdominal surgery; bowel obstruction; pancreatitis; severe malabsorption; malnutrition with increased metabolic demands; trauma or extensive burns

What can PPN contain?

Dextrose, amino acids, electrolytes, vitamins, trace elements, and fat emulsions

How is PPN customized?

Based on laboratory values and nutritional needs

What is the maximum dextrose concentration that can be given peripherally?

10%

Why can PPN irritate veins?

It has a high osmolality/irritating solution

What type of access does TPN require?

Central venous catheter (CVC), such as a PICC, tunneled CVC, or non-tunneled CVC

What are characteristics of TPN?

High osmolality and high glucose content

What can TPN contain?

Dextrose, amino acids, electrolytes, vitamins, trace elements, and fat emulsions

What are the two types of TPN admixtures?

3-in-1 and 2-in-1

What are the primary sources of calories in TPN?

Dextrose (carbohydrates), protein (amino acids), and lipid emulsions (fat)

What is the TPN calorie goal?

20-35 cal/kg/day

What concentrations are lipid emulsions available in?

10%, 20%, and 30%

How can lipid emulsions be administered?

Separately or combined in TPN

Why are lipid emulsions useful for patients at risk for fluid overload?

They provide a large number of calories in a small amount of fluid

What lab value should be monitored with lipid emulsions?

Triglyceride level

What are contraindications to lipid emulsions?

Severe hyperlipidemia; disorders of lipid metabolism such as familial hypertriglyceridemia; egg or soy allergy

What are relative contraindications to lipid emulsions?

Acute pancreatitis with hypertriglyceridemia; severe liver dysfunction; sepsis; uncontrolled diabetes

When should caution be used with lipid emulsions?

Patients at risk for fat embolism

What is the usual protein requirement in TPN?

1-1.5 g/kg/day

Who may require 1.5-2 g/kg/day of protein?

Nutritionally depleted, high-stress, or critically ill patients

What electrolytes may be included in TPN?

Sodium, magnesium, potassium, chloride, phosphate, calcium, and acetate

What are signs that TPN is effective?

Stable weight or gradual weight gain consistent with nutritional goals; increased pre-albumin; balanced electrolytes; BUN in expected range

What is the goal pre-albumin level?

15-35 mg/dL

What is the expected BUN range?

10-20 mg/dL

What are complications of TPN?

Fluid overload; infection; electrolyte imbalances; hyperglycemia; hypoglycemia

Why is fluid overload a concern with TPN?

A large amount of fluid is given with TPN

How should fluid overload be monitored?

Monitor signs and symptoms; daily weights; intake and output

What amount of daily weight gain is concerning for fluid overload?

More than 1 kg/day with edema

Why is infection a concern with TPN?

TPN has a high sugar content

How often should blood glucose be monitored with TPN?

Every 4-6 hours or according to institutional policy

Why does TPN need to be weaned?

Especially when it contains a high dextrose concentration

What should be done if TPN is stopped abruptly or is unexpectedly unavailable?

Administer dextrose-containing IV fluids as prescribed and monitor closely for hypoglycemia

How is hyperglycemia from TPN potentially managed?

Insulin therapy

What is refeeding syndrome?

A serious, potentially life-threatening condition involving sudden fluid and electrolyte shifts when feeding is started in a malnourished patient

Who is at increased risk for refeeding syndrome?

Patients with prolonged severe malnutrition; anorexia; cancer/chemotherapy; prolonged fasting greater than 7-10 days; weight loss greater than 10%; chronic alcohol use

What are signs and symptoms of refeeding syndrome?

Fluid retention; fatigue; muscle weakness; hyperglycemia; confusion; paresthesias; respiratory compromise; electrolyte imbalances

What electrolyte abnormalities occur with refeeding syndrome?

Hypophosphatemia; hypokalemia; hypomagnesemia

What is the hallmark sign of refeeding syndrome?

Hypophosphatemia

What are complications of refeeding syndrome?

Dysrhythmias; respiratory arrest; acidosis; seizures

How is refeeding syndrome prevented?

Start feeding slowly with low calorie intake and gradually increase; monitor labs closely

What should be checked on a TPN order/label?

Patient identifiers and that the ingredients in the solution match the orders

What should the TPN solution be examined for?

Leaks; color change; particulate matter; abnormal clarity; oily appearance; cracks

How often should the TPN bag and infusion set be changed?

Every 24 hours

How should TPN be stored before administration?

Keep refrigerated until 30 minutes-1 hour before use

How should TPN be administered?

Through an in-line filter and infusion pump

Can anything be mixed with TPN?

No, never mix anything with TPN

What type of IV line should be used for TPN?

A dedicated IV line

How should the TPN catheter lumen be labeled?

TPN only

How often are TPN orders usually changed?

Daily after laboratory results

What should be monitored during TPN administration?

Infusion rate; appropriate filter and access device; vital signs; intake and output; daily weights initially; blood glucose; labs

How often should vital signs be monitored with TPN?

Every 4-8 hours or as ordered

What labs should be monitored daily when a TPN patient is acutely ill?

BMP, CBC, hepatic panel, and triglyceride level

How often should labs be monitored once the patient is stable?

At least 3 times per week until stable

How often should a TPN dressing be changed?

Every 7 days or if damp, bloody, loose, or soiled

What should the nurse and patient wear during a TPN dressing change?

A mask

How long should the hub be scrubbed before accessing?

At least 15-30 seconds, then allow it to dry

When can a patient transition from TPN to oral intake?

When oral intake reaches at least 50-75% of calorie intake

How should oral intake be started when transitioning from TPN?

Start with clear liquids, low fat, and avoid irritating substances

What should be monitored during transition from TPN to oral intake?

Calorie count; blood glucose; labs; weights; vital signs; effectiveness

What are criteria for considering transition to enteral nutrition?

Functional GI tract; minimal nausea, vomiting, or diarrhea; stable nutritional and fluid status; no evidence of malabsorption

When can enteral nutrition be considered based on oral intake?

When intake is at least 60-75% of calorie intake orally

What should happen to TPN when transitioning to enteral nutrition?

Gradually reduce TPN as ordered

What percentage of blood is RBCs?

Approximately 44%

What percentage of blood is plasma?

Approximately 55%

What is plasma mainly composed of?

Water, proteins, and electrolytes

What percentage of blood is made up of WBCs and platelets?

Approximately 1%

What are examples of plasma proteins?

Albumin, globulin, clotting factors, and fibrinogen

What is a standard blood donation?

A compatible donor provides approximately 450 mL of blood

What is an autologous transfusion?

The patient's own blood is collected preoperatively at least 6 weeks prior

What are benefits of autologous donation?

Decreased risk of infection and decreased risk for patients with antibodies

What is intraoperative blood salvage?

Blood is collected during surgery using a cell saver, filtered, and reinfused into the patient

How soon must salvaged blood be reinfused?

Within 6 hours of collection

What is directed donation?

A family member or friend with the same blood type donates blood for the patient

What is pooled donation?

A blood product such as platelets is obtained from several donors

How are blood products screened?

Donor history and testing for infectious diseases

What infectious diseases are blood products screened for?

HIV; hepatitis B; hepatitis C; syphilis; West Nile virus; cytomegalovirus (CMV)

What does whole blood contain?

Blood given exactly as received from the donor

What do PRBCs contain?

Only red blood cells

What does FFP contain?

Coagulation factors; fibrinogen; plasma proteins including albumin, immunoglobulins, antithrombin, and other clotting proteins; electrolytes and water

What are the types of platelet products?

Pooled platelets and single-donor platelets

How are pooled platelets obtained?

Platelets extracted from up to 10 donors

How are single-donor platelets obtained?

Platelets retrieved from one donor

What are the indications for whole blood?

Significant bleeding with greater than 25% volume loss

What are the indications for PRBCs?

Symptomatic anemia; significant acute hemorrhage; generally hemoglobin less than 7 g/dL in stable patients

What are the indications for FFP?

Bleeding and coagulation disorders; fluid replacement in massive burns or liver failure; replacement of platelet-aggregating inhibitors in TTP or hemolytic uremic syndrome; urgent warfarin reversal when prothrombin complex concentrates are unavailable

What are the indications for platelets?

Thrombocytopenia; platelet dysfunction; bleeding due to low platelets

What does cryoprecipitate contain?

Factors VIII and XIII; fibrinogen; von Willebrand factor; fibronectin

When is cryoprecipitate indicated?

Fibrinogen less than 100 mg/dL with need for an invasive procedure or severe bleeding

What is albumin?

A plasma protein available as 5% or 25% that acts as a colloid and maintains oncotic pressure