Feeding in critical illness Flashcards
What are the critical care patient groups?
Post-operative e.g. major elective and emergency surgery
Major trauma e.g. head injuries, RTAs, burns, penetrating injuries
Serious sepsis e.g. resp failure, HIV, sepsis
What is a tracheotomy?
Opening in anterior wall of the trachea (tracheostomy)
What are the indications of a tracheotomy?
To secure and maintain a safe airway for certain types of surgery to the head and neck
To facilitate the removal of bronchial secretions when cough ineffective and there is risk of sputum retention
To prevent aspiration of saliva or gastric contents with incompetent swallowing e.g. neuromuscular disorders, unconsciousness, head injuries, stroke etc
To reduce the work of breathing by reducing the anatomical dead space e.g. end stage neuromuscular disease
Whats the difference between metabolic response to injury/disease and starvation?
BMR decreases in starvation but increases in injury/disease
Body fuels and protein conserved in starvation and not in injury/disease
Urinary nitrogen decreases in starvation but increases in injury/disease
Weight loss slow in starvation but rapid in injury/disease
What happens to skeletal muscle when broken down?
It is broken down into constituent amino acids- used as precursors for synthesis of:
Acute phase proteins e.g. CRP
Gluconeogenesis
Immunoproteins e.g. immunoglobulins, complement system proteins
Antioxidants e.g. glutathione synthesis
What causes rapid loss of LBM?
Major elective surgery
Trauma and brain injury
Serious sepsis
What reasons for artificial nutritional support are there?
Support:
Minimise losses-preserve LBM, attenuate metabolic response to stress (catabolism)
Wound healing
Therapy:
Maintain functional integrity of gut- prevent atrophy and decrease intestinal permeability
Modulate immune response- gut associated lymphoid tissue
Stimulate intestinal perfusion/limit ischaemia- reperfusion injury
Prevent oxidative cell damage
What enteral access routes are there?
Differ depending on how patient is tolerating feeding
Nasogastric is first line
Nasojejunal
Nasoduodenal
Orogastric- for patients with trauma to face and only used when patient is unconscious
Cervical pharyngostomy- done surgically, useful in stroke patients or neuro problems who keep pulling out their NG tube as CP is better tolerated
Transoesophageal puncture- patients with head and neck injury
Gastrotomy for patients who need feeding for >1 month
Jejunostomy- permanent feeding
How do you work out how much to feed?
Energy:
Indirect calorimetry- gold standard for measuring energy expenditure
Weight based equation
What can overfeeding of carbs lead to?
Hypercapnia- excessive CO2 retention- increase work of lungs
Hyperglycaemia
Hypertriglyceridaemia
Accumulation of fat in liver
What can overfeeding of protein lead to?
Azotaemia and uraemia (increase urea/N2 compounds in blood due to inadequate renal filtration)
Hypertonic dehydration
Metabolic acidosis
What are the complications of feeds?
Nausea Vomiting Delayed gastric emptying Diarrhoea Constipation
What is parenteral support?
Direct perfusion of nutrients into circulatory system bypassing the GI system but aim to use gut if it works to avoid gut atrophy and reduced perfusion of GI tissue
What are the pros and cons of parenteral?
Pros: Don't need gut Provide nutritional needs Cons: Line complications: Length of insertion Pneumothorax Catheter blockage Central vein thrombosis Line sepsis
Metabolic:
Hyperglycaemic
Lipaemia
Deranged LFTs
Fluid overload
Electrolyte imbalance
Expensive
What are the indications for parenteral use?
GI obstruction/ileus High output fistula Anastomotic breakdown after GI surgery Short bowel syndrome Unable to tolerate enteral feeding
