CC Flashcards
Acute phase response biochemistry
Acute phase response:
* Low albumin
* High CRP
* High WBC
* Deranged LFTS
* Us + Es
Define intubation
Intubation: placement of a flexible plastic tube into the trachea (windpipe) to maintain an open airway or to administer certain drugs.
Define extubation
Extubation: removing an endotracheal tube
Define artificial ventilation
Artificial ventilation: process of simulating normal breathing in a patient who is anaesthetised or unable to breathe for themselves
Define weaning
Weaning: gradual decrease in ventilatory support
Define tracheostomy
Tracheostomy: procedure to help air and oxygen reach the lungs by creating an opening into the trachea (windpipe) from outside the neck. A person with a tracheostomy breathes through a tracheostomy tube inserted in the opening.
Factors indicative of metabolic stress
Factors indicative of metabolic stress
Lab data
* High temperature
* High WBC
* High CRP
* High serum urea (difficult to interpret)
* Low haemoglobin
* Low serum albumin
Clinical indicators
* Anorexia
* Fatigue
* Reduced physical activity
Terminology that describes critical care
Terminiology that describes critical care
* Critical Care Department
* Adult Intensive Care Unit
* Critical Care Unit
* Intensive Care Unit
* High Dependency Unit (more stable/possibly step down but not fit enough to be on ward)
Reasons for being in critical care
Reasons for being in critical care (not exclusive)
* RTA
* Advanced respiratory support
* Complex surgery
* Severe heart attack
* AKI requiring RRT
* Severe pancreatitis
* Sepsis
* Sedation: head injury, epilepsy, cardiac arrest
* Vasopressers: treatment of low blood pressure unresponsive to fluid resuscitation on the ward
* Severe burns (unstable)
* Resuscitation and stabilisation
* Physiological optimisation to prevent MOF
* Facilitate complex surgery
* Support failing organs
* Recognise futility of treatment
* Provide organ support to maintain normal physiology
* Sepsis: Provide vasopressors to maintain organ perfusion & improve BP as antibiotic treatment and immune system combat infection
MOF
MOF = Multi Organ Failure
CVC
CVC = Central Venous Cathether
PENN STATE W MIFFLIN Equation: Women
PENN STATE W MIFFLIN Equation: Women
MIFFLIN: (10 x wt) + (6.25 x ht) - (5 x age) -161
PSU: (MIFFLIN x 0.96) + (Tmax x 167) + (Vm x 31) - 6212
Where,
Wt=kg
Ht= cm
Tmax= Max body temp in 24h
Vm= ventilator l/minute
PENN STATE W MIFFLIN Equation: Men
PENN STATE W MIFFLIN Equation: Men
MIFFLIN: (10 x wt) + (6.25 x ht) - (5 x age) +5
PSU: (MIFFLIN x 0.96) + (Tmax x 167) + (Vm x 31) - 6212
Where,
Wt=kg
Ht= cm
Tmax= Max body temp in 24h
Vm= ventilator l/minute
Ebb phase
Ebb pase
* “HOURS”
* 0-24 h following trauma/injury
* “Untreated SHOCK”
* Body attempting to recover from acute injury/trauma
* Reduction in metabolic activity
* Reduction in oxygen consumption
* Reduced body temperature
* Energy reserves mobilized BUT reduced ability to utilize reserves
* Reduction in REE: hypometabolic state
* Conservation of fluids & electrolytes due to hormones
* Haemodynamic compensation: e.g. vasoconstriction & tissue blood flow shunting: redirection of cardiac output to essential/injured tissues
Ebb phase nutrition specific considerations
Ebb phase nutrition specific considerations
* Minimal-no nutrition advised
* Energy reserves mobilized BUT reduced ability to utilize reserves
* Reduction in REE: hypometabolic state
* Protein losses increase 4 fold (Furst, 2005)
* Critical care patients weight can increase by 10-20% due to fluid shifts (Lowell et al., 1990)
Flow phase
Flow phase
* “DAYS”
* 24-48H +
* “CATABOLIC” phase
* Phase length depends on severity & treatment of trauma/injury
* Hypermetabolism: Increased REE
* Hypercatabolism
Which hormones cause conservation of fluid & electrolytes in the EBB PHASE?
Hormones that cause conservation of fluid & electrolytes in the EBB PHASE
* Vasopressin (Anti-diuretic hormone): may have glycogen mobilizing effect too
* Renin
* Angiotensin
* Aldosterone
Flow phase nutrition specific considerations
Flow phase nutrition specific considerations
* “DAYS”
* 24-48H +
* “CATABOLIC” phase: increase in energy production & consumption
* Phase length depends on severity & treatment of trauma/injury
* Hypermetabolism: Increased REE
* Hypercatabolism: Increased nitrogen losses
* Protein mobilisation caused by: increased catecholamines, glucagon & cortisol
* Increased glucose intolerance: caused by catecholamines
* Aim: prevent further nitrogen losses
* Increase in dietary pro: can reduce but NOT reverse accelerated loss of body protein due to anabolic resistance
* Excess non-protein calories may have adverse effects (Wolfe, 2017)
* “Less is more” : avoid overfeeding
* Muscle, glycogen, lipid mobilised to increase glucose availability
How much LBM can critically ill patients lose per day? (Puthucheary et al., 2013)
Critically ill patients can lose up to 2% of their LBM per day (Puthucheary et al., 2013)
How many kcal/ml is there in Propofol?
There is 1.1kcal/ml in Propofol.
Anabolic phase/Recovery phase nutritional considerations
Anabolic phase/Recovery phase
* “ WEEKS or MONTHS” after catabolic phase
* Appetite increases
* Transfer to positive nitrogen balance
* Improvement in nutritional status possible: ANABOLIC
* Aim: increase muscle mass via increased protein intake & exercise
* Aim: Weight gain
* Increase protein
What happens during the metabolic response to critical illness?
What happens during the metabolic response to critical illness:
* Early acute phase: EBB “SHOCK”
* Late acute phase: FLOW “CATABOLIC”
* Late phase: RECOVERY/REHAB/ANABOLIC
* Disrupted HOMEOSTASIS
* Adaptive stress response to critical illness
Build up of kcal:
* 0-24h
* Day 1-4
* Post Acute ICU phase >Day 5
* Post ICU phase
* Post Hospital Discharge
Build up of kcal:
* 0-24h: no nutrition
* Day 1-4: go slow. Day 1: 25%, Day 2: 50%, Day 3: 75%, Day 4: 100% of target
* Post Acute ICU phase >Day 5: 70% of predictive equations or 100% of indirect calorimetry
* Post ICU phase: 125% of predictive equations/indirect calorimetry or 30kcal/kg/day
* Post Hospital Discharge:150% of predictive equations/indirect calorimetry or 35 kcal/kg/day
(protocol is in place if patient adm on weekend)
Build up of kcal: 0-24H
Build up of kcal: 0-24H
* 0-24h: no nutrition
Build up of kcal: Day 1-4
Build up of kcal: Day 1-4:
* Go slow
* Day 1: 25%
* Day 2: 50%
* Day 3: 75%
* Day 4: 100% of target
(protocol is in place if patient adm on weekend)
Build up of kcal: Post Acute ICU phase >Day 5
Build up of kcal: Post Acute ICU phase >Day 5:
* 70% of predictive equations
or
* 100% of indirect calorimetry
Build up of kcal: Post ICU phase
Build up of kcal: Post ICU phase:
* 125% of predictive equations/indirect calorimetry
or
* 30kcal/kg/day
Build up of kcal: Post Hospital Discharge
Build up of kcal: Post Hospital Discharge:
* 150% of predictive equations/indirect calorimetry
or
* 35 kcal/kg/day
During the flow phase, is the glucose generated by muscle, glycogen and liver mobilisation suppressed by feeding or IV glucose?
No. During the flow phase, the glucose generated by muscle, glycogen and liver mobilisation is NOT suppressed by feeding or IV glucose (Oshima et al., 206)
During the flow phase, what might simultaneous delivery of excess non-protein kcal do?
During the flow phase, simultaneous deivery of excess non-protein kcal may have little benefit & cause adverse effects (Wolfe, 2017)
Anabolic phase/Recovery phase
Anabolic phase/Recovery phase
* Reduced metabolic rate
* Fluid status returns to normal
* Increased appetite
How much glucose does Dextrose 5% have per litre?
Dextrose 5%: 50g of glucose/L
How much kcal does Dextrose 5% have per litre?
Dextrose 5% contains 200kcal
What are catecholamines?
Catecholamines:
* A type of neurohormone.
* Catecholamines are important in stress responses.
Catecholamines, glucagon and cortisol increase during which response?
Catecholamines, glucagon and cortisol increase during the FLOW PHASE.
What do increased catecholamines do during the FLOW PHASE?
Increased catecholamines causes hyperglycaemia and insulin resistance during the FLOW PHASE
What does increased: Cytokines, Catecholamines, Glucagon & Cortisol do during the FLOW PHASE?
Increased cytokines, catecholamines, glucagon and cortisol increases PROTEIN MOBILISATION during the FLOW PHASE.
Increased catecholamines cause ?, ? & ? during the FLOW PHASE
Increased catecholamines cause HYPERGLYCAEMIA, GLUCOSE INTOLERANCE & INSULIN RESISTANCE during the FLOW PHASE
Increased cytokines drives ? during the FLOW PHASE
Increased cytokines drive LEAN TISSUE BREAKDOWN during the FLOW PHASE
How long does the EBB PHASE last?
- The EBB PHASE lasts ~24H (some sources say up to 48H)
- “HOURS”
How long does the FLOW PHASE last?
- The FLOW PHASE lasts 24-48H or MORE
- “DAYS”
How long does the ANABOLIC/RECOVERY PHASE last?
The ANABOLIC/RECOVERY PHASE lasts WEEKS/MONTHS after the FLOW (CATABOLIC) PHASE)
During the FLOW PHASE muscle breakdown is also needed for the generation of which proteins?
During the FLOW PHASE, muscle breakdown is also needed for the generation of ACUTE PHASE PROTEINS (e.g. CRP)
What is the dietetic aim during the FLOW PHASE?
Dietetic aim during the FLOW PHASE:
Energy balance to slow down UNAVOIDABLE muscle/tissue breakdown
What is the dietetic aim during the ANABOLIC/RECOVERY PHASE?
Dietetic aim during the ANABOLIC/RECOVERY PHASE:
* Restore muscle mass (exercise also needed, PHYSIO in hospital)
* Gain weight
* Weight loss could be goal if obese/overweight
A reduction in CRP could indicate that an individual is entering which phase?
A reduction in CRP (still above reference ranges) could indicate that an individual is entering the FLOW PHASE
Which malnutrition screening tools are appropriate for use in Critical Care?
Critical Care MALNUTRITION Screening Tools:
* NUTrition Risk In The Critically Ill (NUTRIC) score (Heyland et al., 2015)
* PENG suggest: NRS-2002
Pros and Cons of the NUTRIC score screening tool
Pros and Cons of the NUTRIC score screening tool
Pros
* Specifically developed & validated for use in critically ill patients
* Helps to identify which patients more likely to benefit from optimal amounts of macronutrients when mortality is considered
* Could be used to guide decisisions for aggressive nutritional support BUT prospective data is lacking
Cons
* Long & complex to use: not practical to complete at bedside due to complexity of the severity of illness scoring required
* Measures clinical parameters more than nutritional
*
Pros and Cons of the NRS-2002 screening tool
Pros and Cons of the NRS-2002 screening tool
Pros
Cons
* May not be as suitable as NUTRIC Score. Coruja et al.: NUTRIC Score identified ~50% of patients in the ICU at high risk of malnutrition whereas NRS-2002 only identified ~35%.
Barriers to obtaining anthropometric measures in Critical Care
Barriers to obtaining anthropometric measures in Critical Care
* Patients might be unable to provide medical/ diet/ anthropometric histories
* Patients may not have medical documentation
* Weight may fluctuate dramatically. CC patients weight can increase by 10-20% in the first 24H.
* CC patients are usually immobile
* CC patients may not be weighed due to haemodynamic instability/ unstable injuries.
* Alternate measures: Ulna, MUAC: not validated for use in CC. Should be used as a guide only
* Traction, casts & braces: provide logistic difficulties: need to be accounted for in resultant measurements.
* Adjusting body wt in amputees: add additional scope for errors.
Is the MUST tool suitable for use in Critical Care?
No, the MUST tool is not suitable for use in Critical Care.
What is haemodynamic instability?
Haemodynamic instability is an insufficient blood flow in the body.
What is haemodynamic instability caused by?
Haemodynamic instability may be caused by (not exclusive):
* heart disease
* high or low blood pressure
* heart failure
* peripheral artery disease
* issues with the heart valves
What is Gastric Residual Volume?
Gastric Residual Volume (GRV) is the amount of liquid drained from a stomach following administration of enteral feed
Considerations following ICU stay
Considerations following ICU stay
* ICU acquired weakness
What is ICU acquired weakness?
ICU-acquired weakness (ICUAW) is ‘clinically detected weakness in critically ill patients in whom there is no plausible aetiology other than critical illness’
Which type of diet should be recommended in those that can eat orally during the recovery phase?
A high energy high protein diet should be recommended to those that can eat during the recovery phase to aid regaining muscle/weight loss.
Why would I choose to use the Penn State University equation instead of the Ireton-Jones equation to estimate energy requirements in CC?
I would choose to use the Penn State University equation instead of Ireton-Jones to estimate energy requirements in CC because:
PSU: More sensitive to metabolic status: REE, temperature & ventilator
PSU: Higher accuracy than Ireton-Jones
PSU: Utilizes MIFFLIN ST JEOR: which includes parameters: age, sex, ht, wt.
I-J: Overestimates in non-obese, underestimates in obese.
What is a limitation of the PSU equation?
According to Frankenfield, the PSU equation is less sensitive in underweight CC/ICU patients (58% accuracy).
When might Ireton-Jones be preferred over PSU?
Ireton-Jones may be preferred over PSU for burns or trauma patients as it was developed for this population.
What are the components of the Global Leadership Initiative on Malnutriton (GLIM criteria)?
Components of the GLIM criteria:
1. Screening of malnutrition (with validated tool)
2. Diagnostic assessment: Phenotypic & aetologic
3. Diagnosis: =/> 1: Phenotypic & 1 Aetologic
4. Grading of malnutrition severity: based on phenotypic criterion
What could a calf circumference measurement be affected by?
A calf circumference measurement could be affected by oedema.
A Japanese study found that the presence of oedema increased a calf circumference by 2cm.
What has been suggested as an alternative to weight estimation in CC?
It has been suggested that a fibula measurement could be utilized instead of visual weight estimation in critical care. Although differences between ethnicities would need to be accounted for (Asian population)
Calf circumference limitations
Calf circumference limitations:
* Doesn’t give indication of muscle strength/quality.
* Could be measuring oedema as well as muscle
* Could be measuring fat
* May not be suitable in those with extreme BMIs (underweight or overweight), but adjustments have been suggested
Hand grip strength is an indication of ? ? not ? ?
Hand grip strength is an indication of muscle function not dietetic treatment
What is BMI adjusted low calf circumference associated with? (Brazilian study)
In a Brazilian study: BMI adjusted low calf circumference is associated with longer hospital stay. Although CC patients were not included in this study.
When is use of ideal body weight indicated?
Use of ideal body weight is indicated in extreme BMIs (underweight or overweight).
Why is ideal body weight suggested in obese patients?
Ideal body weight is suggested in obese patients because use of their actual body weight may lead to overestimation of nutritional requirements (Pinnock, 2022)
What are limitations of the use of IBW?
IBW limitations:
* All IBW formulae predict a single-target body weight as a linear function of height but it the height-weight relationship is complex:
* Weight is affected by: fat mass, muscle mass, presence of oedema/ascites
* No single body weight that applies across all
demographics such as sex, ethnicity and age (Peterson et al., 2016).
* Nor is there a single body weight that applies to all comorbidities and causes of mortality (Peterson et al., 2016).
All IBW formulae predict a single-target body weight as a linear function of height
What could body weight be affected by?
Body weight could be affected by:
* Body volume,
* muscle mass,
* fat mass,
* presence of oedema/ ascites
Which formulae is available for the calcuation of IBW?
Formulae for IBW calcuation:
* Hamwi Formula
* Devine Index
* Robinson Formula
* Miller Formula
* Hammond formula
* Lemmens Formula: 22 x ht squared
* Deitel and Greenstein
Considerations for appropriate IBW
Considerations for appropriate IBW:
* Age: BMI: >25 or 27-32 kg/m2 might be beneficial (Kisac et al., 2022)
* Chronic disease risk increases above 25 kg/m2
* Ethnicity
* Sex
* Nutritional status
Suggested ranges for IBW
Suggested ranges for IBW:
* Body mass index (BMI) of 18.5-24.9kg/m2 (normal range)
* Weight equivalent of 25kg/m2: commonly used by dietitians but no evidence to support this.
* Clinical judgement should be used.
*
Mens Sarcopenia Grip Strength Cut Off
Men Sarcopenia Grip Strength Cut Off:<27kg
Womens Sarcopenia Grip Strength Cut Off
Womens Sarcopenia Grip Strength Cut Off:<16kg
What is anamesis?
Anamesis:
the taking of a patient’s personal medical history
What is an emerging tool for muscle mass measurements in CC/ICU?
Emerging tool for muscle mass measurements in CC:
ultrasound
What is low muscle mass associated with?
Low muscle mass is associated with:
* Impaired immune function
* Impaired strength/ ability to perform daily tasks
* Increased morbidity
* Frailty
* Increased length of hospital stay
* Poor QOL
Muscle mass is affected by ?, ?, ?
Muscle mass is affected by:
* Ethnicity (higher amount in African descendants)
* Sex (higher amount in men than women)
* Age (higher amount in younger adults)
Characteristics of Lambell et al. (2022) ultrasound study/
What did Lambell et al., find about ultrasound use in Critical Care/ICU?
Characteristics of Lambell et al. (2022) ultrasound study:
* 50 participants
* ICU setting
* Pilot cross sectional study
* Australia
* Participants mostly: normal, overweight, obese
* Imbalance of male and female (more males than females)
* More <65y than >65y
What Lambell et al. (2022) found about ultrasound use in CC/ICU:
* Ultrasound could indicate muscle mass in ICU
* Ultrasound is comparable to CT scan
* Traumatic injury was the most common reason for missing ultrasound data
Biochemistry considerations in CC/ICU
Biochemistry considerations in CC/ICU:
* Acute phase/metabolic stress: WBC, CRP, Alb, Haemoglobin
* Hydration: Urea + Electrolytes
* Kidney function: Urea + Electrolytes
* Liver function tests: AST, ALT
* Sepsis: Lactate
* Refeeding bloods: Mg, PO4, K
* Electrolytes: PO4, Adj Ca, Mg.
* Trends & baseline (especially in renal patients)
* Specific biochemical tests related to patients condition/diagnosis
Dangers of overfeeding
Despite the dramatic catabolism, it is not the case the more nutrition the better.
Excess CHO; fatty liver, hyperglycaemia, hypercapnia
Excess fat; alveolar gas exchange is impaired
Excess protein; does not improve overall N balance, increases renal work
Dangers of underfeeding
Dangers of underfeeding (not confirmed by RCTs):
- Poorer patient outcomes
- Increased length of stay
- Prolonged use of mechanical ventilation
- Increased risk of infections
Drugs/medications that may impact nutrition in CC/ICU
Drugs/medications that may impact nutrition in CC/ICU
* Opioid analgesics/sedatives e.g.: morphine, fenatyl
* Propofol (1% & 2%)
* Neuromuscular blocking agents e.g.: atracurium, rocuronium
* Inotropes & vasopressors e.g.: noradrenaline, adrenaline, dobutamine, vasopressin
* Intravenous fluids e.g. crystalloids, colloids
* Prokinetics e.g.: Metoclorpamide, erythromycin
* Phenytoin/roframpicin/ciprofloxacin
* Stress ulcer prophylaxis e.g. lansoprazole, omeprazole, ranitidine
* Citrate & glucose-based dialysis solutions
* Diuretics e.g. furosemide, spironolactone
* Laxatives e.g. senna, lacutlose
* Anti-diarrhoeal e.g. codeine phosphare, loperamide
* Antimicrobials e.g. metronidazole, tazocin, genamicin
* Sliding scale insulin
How do opioid analgesics/sedatives affect nutrition?
Opioid analgesics/sedatives affect nutrition by:
* Reducing gut motility
* Reduced gut motility leads to delayed gastric emptying which can cause constipation, nausea & vomiting
How does Propofol affect nutrition?
Propofol affects nutrition by:
* Providing an additional source of energy (as lipid)
* 1.1kcal/ml
* Risk of fat overload and hyperlipidaemia
What is propofol?
Propofol is an intravenous anaesthetic agent used for induction and maintenance of general anaesthesia
How do PPIs & stress ulcer prophylaxis affect nutrition?
PPIs & stress ulcer prophylaxis affect nutrition by:
* Alteration of gastric pH
* Alteration of gastric pH can affect pH reading for NG placement
How does sliding scale insulin affect nutrition?
Sliding scale insulin can affect nutrition by increasing the risk of hypoglycaemia with interruptions to feeding
Which drugs (if adm enterally) need to be given during a break when enterally feeding to allow for absorption?
Phenytoin, rifampicin, ciprofloxacin need to be given during a break if given enterally to allow for their absorption
Critiques of HCHP/ HEHP diet (check placement presentation)
Advantages/disadvantages for energy requirement equations
Gastric Residual Volume is a surrogate marker for what?
Gastric Residual Volume is a surrogate marker for delayed gastric emptying
