TOTAL PARENTERAL NUTRITION

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TOTAL PARENTERAL NUTRITION

• COMPLICATIONS

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TPN Complications

• MECHANICAL
• METABOLIC
• Glucose Metabolism
• Protein Metabolism
• Fat Metabolism
• Elevated LFTs
• Electrolyte Disorders
• SEPTIC
• Emphasis on prevention

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TPN Complications

• MECHANICAL
• Pneumothorax air
• Hemothorax - blood
• Hydrothorax - solution (TPN)
• Intravascular Misplacement - often IJ
• Catheter Embolism - sheared tip
• Air Embolism
• Venous Thrombosis

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TPN ComplicationsGlucose Metabolism

• Hyperglycemia
• HHCN Hyperglycemic, hyperosmolar, nonketotic
  coma
• Renal threshold for glucose 180 mg/dl
• One episode of hyperglycemia may affect the
  outcome in critical care patient

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TPN ComplicationsGlucose Metabolism

• Hyperglycemia Prevention and Treatment
• Start TPN at 50 ml/hr or with 10 dextrose
• Advance rate at 25 ml/hr each day
• Do not overfeed (lt5-7mg/kg/min)
• Check BS at least daily
• Do not advance if BS gt 200 mg/dl
• If gt 200 give insulin to control BS
• then advance
• May decrease the of total calories
• from dextrose

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TPN ComplicationsGlucose Metabolism

• Rebound Hypoglycemia
• May occur if TPN interrupted for gt 30 min
• Endogenous and exogenous insulin
• Prevention
• Taper TPN before stopping (1/2 rate x 1-2 hours)
• Hang D10

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TPN ComplicationsGlucose Metabolism

• CO2 Retention
• Occurs in pts with resp. dz. (ie. COPD)
• Occurs with overfeeding
• Especially if primary source of calories dextrose
• Prevention
• Feed per nutritional assessment
• Provide mixed substrate

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TPN ComplicationsProtein Metabolism

• Azotemia
• Occurs in pts with renal failure
• Prevention restrict protein
• ARF 0.5-0.8gm/kg/d
• CRF 0.8-1 gm/kg/d
• Dialysis
• Specialized AA formulations??

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TPN ComplicationsProtein Metabolism

• Hyperammonemia
• and Hepatic Encephalopathy (HE)
• Occurs in pts with liver failure
• Restrict protein as necessary
• ie. 0.5 gm/kg/d
• Treat HE with lactulose or antibiotic enemas
• For HE consider Hepatamine

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TPN ComplicationsFat Metabolism

• Essential Fatty Acid Deficiency
• EFA linoleic acid
• Cause TPN without fat
• Prevention Give IV fat emulsion
• Hyperlipidemia
• If trig too high (gt400 mg/dL) give IV fat
  emulsion for EFA only

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TPN ComplicationsAbnormalities of LFTs

• Elevated liver function tests
• AST (SGOT) also from heart
• ALT (SGPT) more specific
• LDH and Bilibrubin
• Possible cause fatty infiltrates of liver
  (hepatic steatois)
• Exceed rate of glucose metabolism
• 5-7 mg/kg/min
• Less risk with cyclic infusion
• (ie. 12hr on 12 hr off)
• Prevention
• Keep rate lt 5mg/kg/min
• Provide mixed substrates (Lipids)
• Provide calories per nutritional assessment
• Possible cause Cholestatis

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TPN ComplicationsFluid and Electrolyte Disorders

• Fluid and virtually any electrolyte
• Refeeding Syndrome
• Low serum levels of intracellular electrolytes
• Hpokalemia
• Hypomagnesemia
• Hypophosphatemia
• Setting Malnourished patients
• Serum lytes may be normal but TBS are low
• Prevention Daily lytes when starting TPN
• Make electrolyte adjustments

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TPN ComplicationsSeptic Complications

• Usually catheter related
• Not commonly from contaminated TPN
• Most common bacteria Staph sp.
• Most common fungi Candida sp.
• Prevention Monitor for SS of infection
• Proper catheter care

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TPN ComplicationsPatient Monitoring

• Catheter Placement
• Blood Sugars
• BUN
• LFTs
• Electrolytes
• Fluid Status
• SS of Infection
• Use a good TPN protocol