Chapter 9: Blood and nutrition Flashcards
What is sickle cell disease?
- Sickle cell disease is the name for a group of inherited health conditions that affect the red blood cells. The most serious type is called sickle cell anaemia.
- most common in those with african or caribbean background
- People with sickle cell disease produce unusually shaped red blood cells that can cause problems because they do not live as long as healthy blood cells and can block blood vessels.
What helps make new red blood cells in sickle cell disease?
- folate supplementation
What reduces the frequency of sickle cell crises?
Hydroxycarbamide
What is glucose-6-phosphate dehydrogenase deficiency?
- inborn error of carbohydrate metabolism
- genetic disorder that affects red blood cells, which carry oxygen from the lungs to tissues throughout the body. In affected individuals, a defect in an enzyme called glucose-6-phosphate dehydrogenase causes red blood cells to break down prematurely.
- predisposes to haemolytic anaemia (spontaneous destruction of rbcs)
- in response to certain drugs/food
Drugs with definite risk of glucose-6-phosphate dehydrogenase deficiency?
- dapsone and other sulphones
- sulphonamides
- nitrofurantoin
- quinolones
- rasbirucase
Symptoms of iron deficiency anaemia?
- tiredness
- pallor (unhealthy pale appearance)
- shortness of breath
- palpitations
When is Prophylaxis required for iron deficiency anaemia?
- malabsorption e.g. crohns
- gastrectomy
- menorrhagia
- chronic renal failure; haemodialysis
- pregnancy
- low birth weight infants
Iron supplements counselling?
- take with or after food (reduce gi side effects: constipation, diarrhoea)
- take with a glass of orange juice (vitamin C aids absorption of iron)
- continue for 3 months after blood levels return to normal
Compound iron preparations?
- folic acid and iron - for pregnant women only (at high risk of iron AND folic acid deficiency)
Parenteral iron preparations, when are they used?
- chronic renal failure with haemodialysis
- malabsorption syndromes
- chemotherapy-induced anaemia
MHRA advice for iron IV hypersensitivity?
MHRA: serious hypersensitivity reactions with IV iron
- take caution with every IV dose (test doses not recommended)
- monitor for 30 mins after each injection (used trained staff and resuscitation immediately available
- high risk in allergies, immune, inflammatory conditions, severe atopic allergies; asthma, eczema. Give if benefit outweighs risk
- avoid in pregnancy, especially 1st trimester
What is megaloblastic anaemia?
- vitamin b12 or folic acid deficiency
Symtpoms of megaloblastic anaemia?
- numbness, tingling of hands/feet, muscle weakness, depression
Vitamin b12 deficiency causes?
- dietary deficiency: –> oral hydroxocobalamin (b12)
- OR malabsorption: gastrectomy, crohns, pernicious anaemia (lack of GI instrinsic factor) –> IM hydroxocobalamin
In megaloblastic anaemia emergencies?
- give both folic acid and vitamin b12, if folic acid is given alone, neuropathy can occur
Folate deficiency causes?
- poor diet
- coeliacs disease: malabsorption
- pregnancy
- anti-epileptics, methotrexate etc
Folate deficiency treatment?
- folic acid daily for 4 months
- never give folic acid alone for megaloblastic anaemia or vitamin b12 deficiency as can lead to neuropathy of the spinal cord
Why should you take caution to avoid iron overload?
can be fatal in children
Treatment for iron poisoning?
DESFERRIOXAMINE
What is neutropenia?
Lower than normal neutrophils (type of white blood cell)
Neutropenia treatment?
FILGASTIM
- recombinant human granulocyte colony-stimulating factor (can reduce the duration of chemotherapy-induced neutropenia)
What are used in hypoplastic and haemolytic anaemia?
- anabolic syteroids, pyridoxine hydrochloride, antilymphocyte immunoglobulin, rituximab (unlicensed) and various corticosteroids
What is used to Mobilise haematopoietic stem cells to peripheral blood for collection and subsequent autologous transplantation in patients with lymphoma or multiple myeloma (specialist use only)?
PLERIXAFOR
What is Immune thrombocytopenic purpura?
Immune thrombocytopenic purpura (ITP) is a blood disorder characterized by a decrease in the number of platelets in the blood. Platelets are cells in the blood that help stop bleeding. A decrease in platelets can cause easy bruising, bleeding gums, and internal bleeding.
How is Immune thrombocytopenic purpura (ITP) treated?
- In adults, initial treatment is usually with a corticosteroid, such as prednisolone.
- Intravenous normal immunoglobulin, or intravenous anti-D (Rh0) immunoglobulin [unlicensed use] may be appropriate in patients with immune thrombocytopenic purpura who are bleeding or at high-risk of bleeding, who require a surgical procedure, or who are unresponsive to corticosteroids. Immunoglobulin preparations may also be considered where a temporary rapid rise in platelets is needed, for example in pregnancy.
- Treatment options for persistent or chronic immune thrombocytopenic purpura include thrombopoietin receptor agonists (avatrombopag, eltrombopag, and romiplostim), rituximab [unlicensed use], or fostamatinib.
Other therapies that have been tried in refractory immune thrombocytopenic purpura include: azathioprine, ciclosporin, cyclophosphamide, danazol, dapsone, mycophenolate mofetil, and vincristine sulfate.
What is the normal range value for Na+?
Normal value: 133-146mmol/L
Symptoms of hypernatraemia?
- convulsions
- hypovolaemia ( a state of low extracellular fluid volume)
- thirst
- dehydration
- oliguria (a urine output that is less than 1 mL/kg/h in infants, less than 0.5 mL/kg/h in children, and less than 400 mL daily in adults)
- postural hypotension
- tachycardia
Drug causes of hypernatraemia?
- oral contraceptives
- corticosteroids
- sodium bicarbonate
- sodium content in IV antibiotics
- lithium
Other causes of hypernatraemia?
- hypernatraemia caused by volume depletion e.g. diabetes insipidus IV GLUCOSE
Symptoms of hypOnatraemia?
- drowsiness
- confusion
- convulsions
- nausea
- vomiting
- headaches
- cramps
Drug causes of hyponatraemia?
- antidepressants
- loop and thiazide diuretics
- carbamazepine
- desmopressin
Treatment of hyponatraemia?
MILD-MODERATE HYPONATRAEMIA
- oral sodium chloride/sodium bicarbonate (add glucose if there is water depletion)
SEVERE HYPONATRAEMIA
- IV saline (isotonic: via peripheral vein OR concetrated: via central vein
- give slowly: risk of osmotic demyelination syndrome
What is given for electrolyte imbalance?
ORAL REHYDRATION THERAPY (K+, Na+, Glucose)
- given over 3-4 hours in diarrhoea
- over 12 hours in hypernatraemic dehydration e.g. diabetes insipidus
What is given to replace water deficit?
IV GLUCOSE
- should not be given alone unless there is no significant loss of electrolytes e.g, hypercalcaemia or diabetes insipidus
Normal level for Cl-?
Normal value: 103mmol/L
*high levels = metabolic acidosis
What is the normal calcium level?
2.10-2.58mmol/L
Hypercalcaemia vs hypercalciuria ?
Hypercalcaemia (too much calcium in the blood) and Hypercalciuria (too much calcium in urine)
What is given to treat hypercalaemia?
- biphosphonates or corticosteroids
What is used to treat hypercalcaemia of malignancy?
calcitonin
What is used to treat hypercalcaemia caused by hyperparathyroidism?
- cinacalcet reduces parathyroid hormone therefore calcium
- paracalcitol - in chronic renal failure
What is used to treat hypercalciruria?
BENDROFLUMETHIAZIDE
- increase fluid intake and reduce dietary calcium
What does hypocalcaemia cause?
Osteoporosis
Treatment of hypocalcaemia?
MILD-MODERATE
- vitamin D and calcium supplements
SEVERE ACUTE OR HYPOCALCAEMIC TETANY
- slow IV calcium gluconate (too rapid = arrhythmias)
Normal magnesium levels?
- normal range: 0.7-1.05mmol/L
When is hypomagnesaemia common?
- common in alcoholics
- hypomagnesaemia also leads to hypo ca2+, K+ and Na+
- IV/IM magnesium sulphate
Normal phosphate range?
0.85 - 1.45mmol/L
Hyperphosphataemia treatment?
Calcium-containing preparations (phosphate-binding agent)
Hypophosphataemia treatment?
Phosphate - given IV if mod-severe
Normal potassium level?
3.5 - 5.3mmol/L
Symptoms of hyperkalaemia?
- ventricular fibrillation
- cardiac arrest
Hyperkalaemia drug causes?
HADBEANS
- Heparin
- Ace inhibs/ARB
- Digoxin
- Beta blockers
- Eplerenone
- Amiloride
- NSAIDs
- Sprionolactone
Hyperkalaemia treatmemt of mild to moderate with no ecg changes?
- calcium resonium
Hyperkalaemia treatment for acute severe hyperkalaemia >6.5mmol/L?
Slow IV calcium gluconate
- IV insulin, glucose and salbutamol can be given in addition
- add sodium bicarbonate to correct compounding acidosis
- do not give via the same line; precipitation = thrombosis
Symptoms of hypokalaemia?
- muscle hypotonia
- arrhythmias
Hypokalaemia drug causes ? (Dare Insult Betty’s Tough Carpet)
- Diuretics
- Insulin
- B2 agonist
- Theophylline
- Corticosteroid
Mild hypokalaemia treatment?
ORAL SLOW POTASSIUM CHLORIDE
- nausea and vomiting causes poor compliance
- smaller doses in renal impairment
- if caused buy diuretic = potassium-sparing diuretic preferred
Severe hypokalaemia treatment?
IV POTASSIUM CHLORIDE
- do not add glucose for initial potassium replacement as glucose causes hypokalaemia
- KCl injection overdose is fatal = use ready-mixed solution or thoroughly mix concentrate
What is Acute Porphyrias?
Genetic defect in haem biosynthesis
- if certain drugs are taken haemolytic anaemia and acute porphyric crises can occur
Treatment of acute porphyric crises?
(Moderate, severe or unremitting crises)
- haem arginate
What is parenteral nutrition?
Parenteral nutrition contains amino acids, glucose, electrolytes and trace elements and vitamins via central or peripheral vein
What is SPN?
Supplementary parenteral nutrition:
- given in addition to oral/enteral feeds
What is TPN?
Total parenteral nutrition: sole source of nutrition
- glucose is given via a central vein to avoid thrombosis
- give enough phosphate to allow the phosphorylation of glucose
- fructose and sorbitol are added to avoid hyperosmolar hyperglycaemic nonketotic acidosis
- do not add additives to fat emulsions unless compatibilty known
When are special diets used ?
- unable to metabolise phenylalanine: restrict dietary proteins, coeliac disease (gluten intolerance): avoidance
Which vitamins are fat soluble?
ADEK
Which vitamins are water soluble?
B and C
What is vitamin A and what does deficiency in it cause/lead to?
RETINOL
- teratogenic
- deficiency = ocular effects; dry eyes and risk of infection
- benefits = night vision, immune system, healthy skin
- sources = liver pates, fish liver oil, raw eggs
What is vitamin C and what do deficiencies lead to?
ASCORBIC ACID
- deficiency = scurvy, gingival bleeding and petechiae
- aids absorption of iron
- claimed to improve the common cold
- benefits = protects cells, wound healing, collagen formation
- sources = oranges, peppers, tomatoes, blackcurrants
What is calciferol and what can deficiency lead to?
- VITAMIN D
- deficiency = rickets and osteomalacia
- d2 = ergocalciferol
- d3 = cholecalciferol
- give hydroxylated versions in severe renal impairment = alfacalcidol, calcitrol
- if nausea and vomiting occurs - check plasma concentration
- benefits = vitamin D is needed for dietary absorption of calcium. Maintain Ca and PO4 levels. Healthy bones and teeth
What is tocopherol and deficiencies?
- VITAMIN E
- inhibits platelet aggregation; increased risk of bleeding with warfarin
- benefits = powerful antioxidant which protects free radicals, healthy skin, eyes
- sources = plant oils e.g. olive oil, nuts and seeds, wheat germ
What is phytomenadione ?
- VITAMIN K = blood clotting
- phytomenadione = lipid soluble
- menadiol = water soluble used in liver impairment
- vitamin K given to all new born babies to prevent neonatal haemorrhage
- do not give vitamin K with warfarin; antagonising effect
- sources = green leafy vegetables
What is thiamine and when is it used?
- VITAMIN B1
- used in wernickes encaphalopathy.
- anaphylaxis with vitamin b1 injections
- benefits = b vitamins release energy from food, healthy CNS
- sources = fortified cereals, wholegrain
What is riboflavin?
- VITAMIN B2
- benefits = healthy skin, nerves and eyes
- sources = milk, eggs, fortified cereals, rice
What is Niacin?
- VITAMIN B3
- available as nicotinamide (preferred) and nicotinic acid (vasodilation side effect)
- benefits = healthy skin and eyes
- sources = meat, fish, wheat flour, eggs, milk
What is pyridoxine?
- VITAMIN B6
- prevents peripheral neuropathy; given with isoniazid/penicillamine
- risk of sensory neuropathy with prolonged use of high doses >200mg. Treats premenstrual syndrome
- benefits = helps make several neurotransmitters, haemoglobin
- sources = fortified cereals, chicken, veg
What is biotin?
- VITAMIN B7
- used to strengthen hair and nails
- benefits = essential for fat metabolism
- sources = range of foods; vegetables, whole cereals
What is cobalamin/hydroxocobalamin?
- VITAMIN B12
- treats megaloblastic anaemia.
- b12 deficiency is common in vegans
- benefits = healthy nervous system, makes RBCs, processing folic acid
- sources = meat, salmon, fortified cereals
What is taken by pregnant women to reduce the risk of neural tube defects e.g. spina bifida?
- folic acid 400mcg daily
- before conception and until week 12 of pregnancy
What is the dose of folic acid for women in high risk pregnancy groups?
- folic acid 5mg daily
- before conception and until week 12
High risk groups:
- anti-epileptic medication
- diabetes
- previous infant witj neural tube defect
- sickle cell disease: give throughout whole pregnancy
How long should pregnant women take folic acid?
- before conception and until week 12 of pregnancy
- *apart from sickle cell disease = take throughout whole pregnancy
