Exam 3 - Critical Care Flashcards
What are the 3 types of metabolic stress?
- Sepsis (full body infection)
- Trauma (including burns - most hyperbolic state a body can be in)
- Surgery
What are the 3 phases to the metabolic response to stress?
- Ebb Phase
- Flow Phase
- Recovery (or Resolution) Phase
Goal is to move body back to a place where it is better able to heal
What is the metabolic response to stress?
- Involves most metabolic pathways
- Accelerated metabolism of lean body mass (LBM)
- Negative nitrogen balance
- Muscle wasting
Ebb phase
- Immediate: hypovolemia (low blood pressure), shock, tissue hypoxia (not enough blood flow)
- Decreased cardiac output - causes very low blood pressure, must be stabilized or else patient will die
- Decreased oxygen consumption
- Lowered body temperature
- Insulin levels decrease because glucagon is elevated
ARDS = acute respiratory distress syndrome, can cause state of acidosis
Flow phase
- Follows fluid resuscitation and restoration of oxygen transport
- Increased cardiac output begins
- Increased body temperature
- Increased energy expenditure – very hypermetabolic, this is where the loss of lean body mass happens
- Total body protein catabolism begins
- Marked increases in glucose production, FFA release, circulating insulin, catecholamines, glucagon, and cortisol
- Presser = anything utilized to stabilize BP (BP must be stabilized to initiate nutrition support, won’t feed patients unless it’s assumed they will live)
want a slight elevated glucose level for bodys natural trauma response
What is the hormonal and cell-mediated response to stress?
- Hormones cause protein catabolism
- BCAA oxidation
- Mobilization of acute-phase proteins
Rapid loss of LBM and negative nitrogen balance - Increased circulation of FFAs
- Hyperglycemia
- Sodium and water retention
What are the main differences in starvation vs stress response?
Stress
* increased REE, mixed fuel source, hormone mediated response
* increased: gluconeogenesis, proteolysis, branched-chain oxidation, hepatic protein synthesis, ureagenesis, urinary nitrogen loss
Starvation
* Starvation = decreased energy expenditure, use of alternative fuels, decreased protein wasting, stored glycogen used in 24 hours
* Late starvation = fatty acids, ketones, and glycerol provide energy for all tissues except brain, nervous system, and RBCs
What is systemic inflammatory response syndrome (SIRS)?
- SIRS is the inflammatory response that occurs in infection, pancreatitis, ischemia, burns, multiple trauma, hemorrhagic shock, and organ injury
- Common complication: multiple-organ dysfunction syndrome (MODS)
- Patients are hypermetabolic
- Gut hypo-perfusion can result in: 1) Ileus (lack of peristalsis); enteral feeding helps restores gut function. 2) Bacterial translocation
What is Septicemia?
full body infections, when someone is septic they are far more likely to die
Diagnosis of Systemic Inflammatory Response Syndrome (SIRS)?
Site of infection established and at least two of the following are present
* Body temperature >38 C or <36 C
* Heart rate >90 beats/min
* Respiratory rate >20 breaths/min (tachypnea)
* PaCO2 <32 mm Hg (hyperventilation)
* WBC count >12,000/mm3 or <4000/mm3
* Bandemia: presence of >10% bands (immature neutrophils) in the absence of chemotherapy-induced neutropenia and leukopenia
What is Multiple organ dysfunction syndrome (MODS)?
- Lung failure
- Liver failure
- Intestinal failure
- Kidney failure
- Hematologic and cardiac failure
- CNS changes can occur at any time
Patients usually pretty heavily sedated in severe infections
IAP = intraabdominal pressure >20 mmHg
What is abdominal compartment syndrome?
- Can be a complication of major abdominal trauma, bowel distension, and shock
- Caused by increased intraabdominal pressure
- Hemodynamic instability; respiratory, renal, and neurologic consequences
- Elevated nutritional and fluid needs
- Enteral nutrition
pressure is so great, they cut it open to release the pressure
What is the MNT for Critical Care?
Goals
* Minimize starvation
* Prevent or correct specific nutrient deficiencies
* Provide adequate kilocalories
* Use suggested critical care formulas
* Manage fluid and electrolytes
* * Begin enteral feeding when hemodynamically stable
Nutrition support alone cannot abolish hypermetabolism
What are the energy requirements in critical care?
- Indirect calorimetry is best for determining energy requirements
- Early feeding (within 24 to 48 hours)
- Avoid overfeeding due to metabolic rates fluctuating so much (RQ over 1.0 indicates overfeeding, under .7 indicates underfeeding)
- Glycemic control
What calculations should be used for energy requirements in critical care?
- 25 to 30 kcal/kg/day (actual body weight for BMI 20-29)
- Penn State University, Ireton Jones
- Hypocaloric, high protein feedings best in obese critically ill
- 50% to 70% of estimated kcal needs
- Protein at 1.2 g/kg actual weight or 2 to 2.5 g/kg of ideal weight
- Permissive underfeeding 18-22 kcal/kg IBW and 1.5-2.5 g/kg IBW protein
- vitamins, minerals, and traces elements should be included
- Early EN is best (formula selected based on GI function)
