Smith and Pat Flashcards
Why is malnutrition common in UK hospitals?
- Not recognised as a clinical problem
- Increase in energy need of some medical problems
- Poor intake.
Explain the catabolic response to trauma?
- Rise in catabolic hormones such as adrenalin, noradrenalin and cortisol.
- These antagonise the effect of insulin.
- These coupled with rises in cytokines will cause an increase in fatty acid oxidation, a relative decrease in glucose oxidation and an out flow of amino acids from muscle.
Explain social factors that may lead to inadequate nutritional status in the community?
- Limited mobility
- Depression
- Limited cooking skills
- Recent bereavement
- Social isolation
List 3 potential advantages of breast feeding (NB: for mother and child). [3]
- Correct temperature
- Decrease risk infections especially respiratory, GIT, EAR.
- Low solute load
- High bioavailability
- Easily digested
- Increase IQ?
- Decrease risk IDDM & IBD
- Decrease risk maternal breast cancer
- Promotes ‘normal’ gut flora.
List 2 potential disadvantages of breast feeding (NB: for mother and child). [2]
- Transfer of environmental pollutants mum has been exposed to
- Transfer of HIV, CMV, and hepatitis.
At what age (in months) does the World Health Organisation guidelines suggest weaning of an infant should start [2]
6 months
What is the reason for the guidelines suggesting this age to start weaning [3]
To decrease morbidity (1 mark) and mortality (1 mark) from infections in developing counties (1 mark).
What happens to basal metabolic rate and protein breakdown in response to critical illness? [4]
Increase BMR (2 marks) and increase protein breakdown (2 marks)
What happens to nutritional intake in response to critical illness? [1]
It is reduced
What is the complication of losing 40% of lean body mass and what is the usual cause? [2]
Death (1 mark) the usual cause is pneumonia (1 mark)
After making your initial judgement on the basis of the history and your examination of a patient, is it absolutely necessary to measure plasma protein levels before deciding to commence nutrition therapy? Briefly explain your answer. [3]
- No (1 mark)
- Plasma protein levels can be useful but not necessary for decision on nutrition therapy. Low plasma proteins may be due to malnutrition but in acutely sick patients are more likely due to other factors such as liver disease, post-surgery etc (1 mark).
- Plasma proteins are affected by acute phase protein response, for example a rise in C-reactive protein will be followed by a drop in Albumin (1 mark).
Obesity is linked to a number of diseases such as diabetes, coronary heart disease. Apart from physical illness list 3 other major social costs of obesity in adults. (3 marks)
- 18 million sick days
- 30,000 deaths a year resulting in 40,000 lost years of working life
- Deaths linked to obesity shorten life by 9 yrs
- Lower achievement in the work place
- Depression and increased psychological disorders
Who, if either, would have the greater risk of heart disease: a male with a body mass index (BMI) of 25kg/m2and a waist measurement of 95cm or a male with the same BMI but with a waist measurement of 110cm? (1 mark)
- BMI=wt (kg)/high m2
- BMI is a method of associating health risk to body weight while controlling for height
- BMI of 25 with a waist of 110cm
Write a short explanation of the initial consequences of insulin resistance. (2 marks)
Insulin resistance = abnormal carbohydrate + lipid metabolism
How are obesity and insulin resistance linked? (4 marks)
- Increase in body weight is a function of increased adipocyte cell size (1)
- As adipocyte cell size increases sensitivity of the tissue to insulin falls (1) possibly due to increase TNF release from the adipocyte itself and monocytes within adipose tissue (1)
- Insulin resistant adipocytes release greater amounts of free fatty acids which relate to a decline in insulin sensitivity in muscle due to preferential oxidation of free fatty acids and a decrease need of glucose (1)
There are a number of genetic variants which can cause abnormal metabolism of drugs used in anaesthesia. One metabolic pathway subject to genetic variants that may cause problems for anaesthetists is ester hydrolysis.
a. Name the enzyme with abnormal phenotype. (1 mark)
b. Where is this enzyme found? (1 mark)
a) Butyrylcholinesterase or plasma cholinesterase
b) In the plasma
Suxamethonium is an example of a drug used in anaesthesia metabolised by this enzyme. What is this drug used for in anaesthesia? (1 mark)
As a muscle relaxant (or, neuromuscular blocking agent) used to paralyse patients prior to procedures such as intubation
What happens to a patient who is homozygous for an abnormal phenotype if they are given this drug and why? (2 marks)
- They remain paralysed for several hours because the drug is an agonist at the motor endplate and causes a depolarising paralysis.
- It will eventually be metabolised, but very slowly, some will also be excreted unmetabolised and so the effect will gradually wear off spontaneously.
Under these circumstances, what must the anaesthetist do to ensure the patient’s safety? (1 mark)
Ventilate the patient, and give sedation to prevent distress or panic, until the spontaneous resolution of block.
Problems with the ester hydrolysis pathway may also be acquired. What do you think would be the implication in a patient with liver disease, or if the patient were malnourished with a low BMI? (2 marks)
- As butyrylcholinesterase is a plasma protein manufactured in the liver, both liver disease and malnutrition could result in low levels of butyrylcholinesterase.
- This could lead to reduced metabolism of Suxamethonium & Mivacurium with the associated problems of prolonged paralysis.
Another genetic condition that is important to the anaesthetist is malignant hyperpyrexia or malignant hyperthermia. Briefly describe why this condition is important to the anaesthetist. (2 marks)
- Malignant hyperpyrexia (or malignant hyperthermia) is a potentially fatal reaction to certain anaesthetic agents including ALL the anaesthetic vapours and the depolarising muscle relaxant suxamethonium. (1 mark)
- The condition results from a massive increase in muscle metabolism stimulated by the anaesthetic agents (often likened to a “metabolic storm.”) and produces high temperatures, high oxygen consumption, metabolic acidosis, hyperkalaemia, high plasma creatinine kinase and myoglobinuria. (1 mark)
In a patient with nasopharyngeal colonisation due to streptococcus pneumoniae, list 4 host components which initially defend against invasiveinfection. (4 marks)
- Secretory IgA
- Natural IgM
- Ciliae
- Defensins
- Collectins (include MBL)
- Epithelial cell tight junctions etc
- Complement-(less important)
List 2 bacterial factors which might allow attachment or penetration of the epithelial barrier. (2 marks)
- Ig or complement binding proteins
* Internalisation via fibronectin binding proteins
List 2 bacterial factors which might allow the streptococcus pneumoniaeto evade the immune response in the lung. (2 marks)
- Peptidoglycan cell wall
- Capsule
- Complement binding
- Ig binding
Which host factors might allow variation in the response? (2 marks)
(Sepsis section)
- MBL
- TNF
- HLA
- Prior exposure/level of antibody/vaccination
Outline 4 options for managing a patient who has lost the use of his own kidneys. (4 marks)
Which of the above options is associated with the best life expectancy and quality of life? (1 mark)
- Symptomatic / conservative management
- Peritoneal dialysis
- Haemodialysis
- Renal transplantation
Part 2: Renal transplantation
Identify 3 symptoms a patient with chronic renal failure may complain of. (3 marks)
- Shortness of breath
- Ankle swelling
- Itching
- Anorexia
- Nausea and vomiting
- Lethargy/tiredness
Identify 4 of the commonest causes of chronic renal failure in the UK. (2 marks)
- Diabetes mellitus
- Hypertension/renovascular disease
- Polycystic kidney disease
- Pyelonephritis
- Glomerulonephritis
During moderate intensity exercise, is PaCO2(partial pressure of carbon dioxide in arterial blood), reduced, increased or unchanged from rest? Briefly explain your choice. (2 marks)
Unchanged – alveolar ventilation increases in precise proportion to carbon dioxide production (VCO2) so that blood gas levels are maintained constant
During very heavy exercise, is PaCO2reduced, increased or unchanged from rest? Briefly explain your choice. (2 marks)
Reduced – above the AT, the increased lactic acid is initially buffered so that isocapnia is maintained. As the exercise intensity continues to increase to heavier levels, the buffering of lactic acid can’t keep pace with the increased lactic acid resulting in an accelerated ventilatory response (‘respiratory compensation’) without an associated acceleration of VCO2. Thus PaCO2 is driven down.
Explain the difference between ‘hyperventilation’ and the ‘hyperpnoea’ of exercise. (2 marks)
- Exercise hyperpnoea is an increase in ventilation that is appropriate for the metabolic demand (blood gases maintained) – accompanied by increase in VCO2.
- Hyperventilation is an increase in ventilation that exceeds metabolic demand – and is not associated with an increased VCO2 resulting in reduced PaCO2
What is the source of CO2during aerobic and anaerobic metabolism? (2 marks)
- Aerobic = oxidation of glycogen and fatty acids.
* Anaerobic metabolism – buffering of lactic acid
Describe (briefly) a graphical method for determining the anaerobic threshold during incremental exercise. (2 marks)
• Plot of VCO2 (y-axis) versus VO2 (x-axis) (v-slope method). AT is taken as the point at which the VCO2 starts to increase faster than the VO2 causing slope of plot to exceed 1.
Or
• Plot of Ve/VO2 against workload (ventilatory equivalent for oxygen). AT is taken as the upward inflection of this plot. (Take off 1 mark if VE versus VCO2 is mentioned instead of VE verses VO2)
• Other plots they may mention include PETO2 versus time or VCO2 and VO2 against time (not easy to get it from these so give them 1 mark only)
Staphylococcus aureus – what kind of gram staining? [1]
Positive
Toxic shock syndrome host receptors [2]
MHC2 on monocytes + T-cell receptor
2 common diseases caused by bacteria. [2]
Pneumonia, cellulitis, septicaemia
Clostridium difficile – what kind of gram staining? [1]
Positive
Virulence factors for C. difficile. [2]
tcdb and tcda (Toxin A and B)
2 diseases that C. difficile causes. [2]
Pseudomembranous colitis and sepsis
What is volatile and non volatile acid? (2)
Volatile = CO2 Non-volatile = lactic acid
a) How much volatile/non volatile produced in a day (mmol)? (2)
b) pKa value (1)
c) Normal pH value (1)
Volatile = 13-15000 mmol/day Non-volatile = 1500mmol/day
b) 6.1
c) 7.4
What is ratio of HCO3 to CO2 (1)
20:1
Define base excess or deficit (2)
Base excess: Amount of strong acid that has to be added to produce normal pH 7.4 in sample
Base excess > + 2 mmol/l: metabolic alkalosis
Base deficit: Amount of strong base to be added to produce normal pH 7.4 in sample
Base deficit more negative than - 2 mmol/l: metabolic acidosis
What are factors contributing to adverse drug reactions (3)
- Abnormal pharmokinetics due to genetic factors
- Abnormal pharmokinetics due to comorbid states
- Polypharmacy – multiple medications
What scheme is in place to report ADR? (1)
Yellow card scheme
What is the regulatory body for this? (1)
To report ADR
Medicine and Healthcare products Regulatory Committee
What does a black upside down triangle mean? (1)
Newly licensed drug less than two years
What is ADR of Amiodarone, Ciclosporin?, and another one beginning with C? possible answers: Pulmonary fibrosis, Cardiac arrhythmias, Tendonitis (3)
- Amiodarone inhibits CYP450, therefore cyclosporine more abundant and less metabolized, leading to toxicity.
- Amiodarone = photosensitivity and pulmonary fibrosis
- Cyclosporine = nephrotoxicity and pancreatitis
What is normal BP? (1)
120/80mmHg
WELL DONE ehehehe (I totally knew this :P)
How do you calculate MAP and Pulse Pressure from this? (1)
- MAP = CO x Total Peripheral Resistance
- MAP = DP + 1/3PP
- Pulse Pressure = SP – DP
I KNEW THIS TOO
What happens to SBP/DBP in dynamic exercise and static exercise? (2 +2)
- BP increases more in static exercise and less in dynamic exercise.
- BP = TPR x CO
- TPR decreases, CO increases relatively more, therefore BP increases.
- TPR decreases because vasodilation of arterioles providing oxygen to skeletal muscle.
- CO increases to deliver oxygen to muscle to meet their demand.
- In dynamic exercise; SBP increases but DBP stays constant.
- In static, both increase.
From this, why should pts with Ischaemic Heart Disease not to static exercise? (3)
- IHD = lack of o2 delivery to the heart due to coronary artery disease or atherosclerosis.
- Static exercise increases both Systolic and diastolic pressures.
- Increase in BP would increase resistance, therefore, further impairing oxygen delivery leading to an MI.
What is the class of agents used to enhance performance by having effects on staying awake? (1)
Stimulant e.g. caffeine
Renal failure-mechanism for met acidosis with and without raised anion gap? (2)
- Normal anion gap: HCO3- loss (from gut or kidney)
- Anion gap > 18: added acid anion, commonly
- Lactate
- Ketoacids
What happens during starvation to glucose/protein/fat/energy expenditure-decrease/increase/normal? (2)
- BMR decreases.
- Glucose decreases
- Protein decreases but lesser extent than fat, only used where necessary, tried to be protected
- Fat decreases.
What 2 questions do you ask for assessing nutritional risk? (2)
- Have you lost weight recently?
- Has the amount you eat changed?
- GI symptoms? Vomiting? Diarrhoea?
What are the 4 most common diseases associated with obesity? (4)
- T2DM
- Cancer
- Arthritis
- Stroke
- Hypertension
- Coronary Artery Disease
Which two hormones are affected in Chronic Renal Failure? (3 marks)
Vitamin D (calcitriol) and erythropoietin
At which GFR does the patient start to become symptomatic? Give units. (2 marks)
80ml/min
What is value which oliguria? Give units. (2 marks)
Less than 300-500 ml/day
List three dietary restrictions for a patient with renal failure. (3 marks)
Low protein, low potassium and low phosphate
Give an example of a nephrotoxic agent. (1 mark)
Gentamicin, ACE inhibitors, e.g. enalapril
Which is obese? Give 3 reasons. (4 marks)
- High BMI > 30kg/m2
- Lowest VO2 max
- Low anaerobic threshold
- Lowest work peak
Which is the athlete? Give 3 reasons. (4 marks)
- High Vo2 max
- High anaerobic threshold
- High work peak
a) Which subject lacks the glycolytic enzyme? Justify. (2 marks)
- Anaerobic threshold would be lowest
* Because glycolytic enzyme not present, therefore must constantly respire anaerobically
Streptococcus pneumoniae.
Which gram stain is this bacteria? (1 mark)
Gram positive
Streptococcus pneumoniae.
List two infections that it causes. (2 marks)
Pneumonia
meningitis
a) Give two host factors that stimulate opsonophagocytosis by binding to the pathogen? (2 marks)
- Complement (C3b) deposition on bacterial surface
- Antibody (IgG) against pneumococcal polysaccharide
- Mannose binding lectin deposition
List four conditions, excluding cardiac conditions, renal disease and age, where the host would be immunocompromised. (4 marks)
- HIV
- Chemotherapy
- Pregnancy
- Transplant
- Cancer
- Rheumatoid arthritis
- Systemic Lupus Erythematosus
- Malnourished
- Infection
- Iatrogenic (post-transplant)
- Trauma
- Alcoholism
- Radiotherapy
- Leukaemia
- Hyposplenism (asplenism)
- Burns
(Goodness me he’s overachieving)
A patient has been given Ramipril and Spironolactone. Which biochemical abnormalities might you see with these two drugs? (2 marks)
Hyperkalaemia, acidosis, hyponatraemia
Guy with Diabetes. Name 5 classes of anti-hypertensives that have been proven to be effective in clinical trials. (4 marks)
ACEI, ARB, CCB’s, Renin antagonists, aldosterone antagonists, diuretics, e.g. thiazides, alpha blockers
Give the name of one trial. (1 mark)
Double-blind placebo control
Name the mechanism of Simvastatin and give two biochemical abnormalities you would see. (3 marks)
HMG CoA reductase inhibitor
Liver enzyme derangements – high alkaline phosphatase, hyperkalaemia, metabolic acidosis, high CK.
Give two factors that would lead to Sarcopenia? (2 marks)
- Ageing
- Sedentary lifestyle
- Malnutrition (protein deficiency)
- Immobility
- Low GH/testosterone/IGF
- Low protein synthesis