NUTRITION IN THE SURGICAL PATIENTs

Caloric sources

Three major sources: protein, carbohydrate, and fat

Amount of glycogen is limited, only can supply 3765.6 KJ（900 kcal），comprise ½ of daily requirement

Protein cannot be considered as an energy source.

Body fat is the main energy storage about l5Kg. In starvation fat provides the bulk of calories with little effect on organ function, but certain amount of protein also be oxidized

Anthropometry：

Malnutrition: body weight loss > 15%，t

Viscera protein: albumin, etc.

Incapable of oral ingestion > 5-7 days

Preoperative preparation of malnutrition patient, digestive tract fistula, acute severe pancreatitis, short bowel syndrome, severe infection, large area burning, and hepatic, renal failure, etc.

PN after major operation is beneficial to patient's recovery, especially abdominal surgery

Intestinal inflammatory diseases: ulcerative colitis, Crohn disease

Nutrition support may promote tumor proliferation and development, so it should be used in combination with chemotherapy.

Glucose

Main energy source of PN, only 100 g/24 h can save protein

Advantages: sufficient origin, low price, convenient to know its utilization status through monitoring blood & urine glucose 

Disadvantages:

  • High concentration: 25% & 50%，irritable to vein 
  • Limit of body utilization: 5 mg/(kg·min)
  • Surgical patients combined with DM are more susceptible to   
  • Glucose metabolism disturbance
  • Under stress, body utilization rate decrease, extra glucose turn into fat, dispose in organs

Electrolytes

Potassium, sodium, chloride, calcium, magnesium and phosphorus 

Vitamins

Water soluble: thiamine, riboflavin, niacin, pantothenic acid, pyridoxine, folic acid, B12

Fat soluble: A, D, E, K

Trace metals

Zinc, Copper, Chronium, Selenium, Manganese, Iron

Technical complications: 

  • Related to central venous catheter: pneumothorax, injury of blood vessel, nerve or thoracic duct due to puncture.
  • Air embolism
  • Insufficient replenishment
  • Serum electrolyte disturbance
  • Trace metal deficit
  • Essential fat acid deficit

Hypo/hyperglycemia

  •        Hypoglycemia: over-dosage of extraneous insulin
  •        Glucose infusion rate too rapid
  •        Decreased utilization of glucose

Liver function damage

  •        Liver steatosis due to overfeed of glucose
  •        Use fat emulsion as part of energy source

Stone formation in the gall bladder: long-term PN without food stimulation to the gut

Mild abnormalities of serum transaminase, alkaline phosphatase and bilirubin levels may occur in many parenterally nourished patients. Intestine barrier function impaired due to lack of food stimulus to the intestine and glutamine insufficiency

Infectious complications

Sepsis secondary to contamination of the central venous catheter

Causes:
Systemic sepsis
  • Hematogenous seeding of the catheter with bacteria
  • Failure to observe strict aseptic precautions during preparation & administration of the solutions
  • Clinical manifestations:
  • Sudden development of glucose intolerance
  • Fever
  • Infectious complications
  • Sepsis secondary to contamination of the central venous catheter

Management
  • Other causes of fever also should be investigated
  • If fever persists, the infusion catheter should be removed and cultured
  • Should evidence of infection persists over 24-48 h without a definable source, the catheter should be replaced in the opposite subclavian vein, and antibiotics also should be administrated

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