Indirect Calorimetry and Metabolic Cart
Indirect calorimetry is a technique that measures inspired and expired gas flows, volumes and concentrations of O2 and CO2. The equipment used is also known as a metabolic cart
Intolerance to Enteral Nutrition
OVERVIEW CAUSES Patient Mechanical Drugs ASSESSMENT History Examination Investigations MANAGEMENT General approach Approach to gastric residual volumes >500mL q6h References and Links LITFL Journal articles
Nasogastric tube vs PEG vs Jejunostomy
Nasogastric tube vs Percutaneous endoscopic gastrostomy (PEG) vs Jejunostomy
Nutrition Literature Summaries
summaries of key studies from the intensive care nutrition literature
Nutritional Assessment in the Critically Ill
Nutritional Assessment in Critical Illness: poor nutritional state is a common feature of critically ill patients, either pre-existing or as a result of the illness
Overfeeding
In the 1980s, the concept of parenteral hyperalimentation or hypercaloric feeding was dominant. This was stopped due to the sequelae, which limit attempts to rapidly correct malnutrition. Some early studies suggesting harm from early feeding were actually showing the effects of overfeeding
Periprocedural Fasting
Periprocedural fasting is widely performed with little evidence base. NBM = nil by mouth; NPO = nil per oral
Prokinetics
Prokinetics are agents that increase gastrointestinal motility. Gastroparesis common -> increased gastric residual volumes -> GORD, aspiration risk and inability to meet nutrition targets. Theoretically, an increase in gastric motility helps in establishing target enteral feeds early in critically ill patients, which improves outcome
Refeeding Syndrome
Refeeding Syndrome = a group of clinical findings that occur in severely malnourished individuals undergoing nutritional support.
Starvation Response
Starvation response: adaptive hypometabolic state; unlike most other species, human brains can also use ketones as fuel, so muscle (i.e. protein) can be relatively spared in favour of fat as the primary energy fuel during prolonged starvation
Substrate Metabolism – Rest versus Stress
Rest = basal metabolic rate + minimal exercise. Major stress = 50% burn. The body's goal is to preserve plasma glucose levels for brain metabolism.
John Birkett
John Birkett (1815-1904) was an English general surgeon.