Editing Nutrition – RN Flashcards (section)

== Parenteral Nutrition ==

;Why does TPN require central venous access?
:TPN is hypertonic, typically more than 10 percent dextrose and above roughly 900 mOsm/L. Given peripherally it causes severe phlebitis and vein destruction. A high-flow central vein dilutes it rapidly.

;What happens if TPN is stopped abruptly, and what should the nurse do?
:Rebound hypoglycemia occurs because circulating endogenous insulin remains elevated. Taper the rate rather than stopping, and if the bag is empty or unavailable, hang 10 percent dextrose in water at the same rate and notify the provider.

;Why is TPN never sped up to catch up a delayed infusion?
:A sudden dextrose bolus causes hyperglycemia, osmotic diuresis, and dehydration. The rate is maintained as ordered and the provider is notified if a significant volume is missed.

;What are the key TPN infection control measures?
:Strict aseptic technique, a dedicated lumen, an in-line filter, an infusion pump, bag and tubing changed every 24 hours, no bedside additives, and site assessment every shift. New fever in a client on TPN is a catheter-related bloodstream infection until proven otherwise.

;What are the signs and immediate management of venous air embolism?
:Sudden dyspnea, chest pain, hypotension, tachycardia, and sometimes a churning precordial murmur. Clamp the catheter, place the client in left lateral Trendelenburg position, administer 100 percent oxygen, and call for help.

;What is refeeding syndrome and what is its hallmark laboratory finding?
:A dangerous intracellular shift of electrolytes when nutrition is reintroduced to a starved client. The hallmark is hypophosphatemia, accompanied by hypokalemia, hypomagnesemia, and thiamine depletion, which can cause dysrhythmias, heart failure, respiratory failure, seizures, and death.

;How is refeeding syndrome prevented?
:Identify at-risk clients (anorexia nervosa, chronic alcohol use, prolonged fasting or NPO status, cachexia, malabsorption), start at low calorie loads and advance over several days, replace thiamine before feeding, correct electrolytes before and during initiation, and monitor phosphorus, potassium, magnesium, cardiac rhythm, and fluid status closely.