Clinical Pathology Flashcards
What is blood pressure?
blood pressure is defined as the amount of pressure exerted on the walls of the arteries as the blood moves through them
How is blood pressure measured?
systolic pressure
- blood pressure exerted when the heart beats and forces blood around the body
diastolic pressure
- blood pressure when the heart is at rest between beats.
What is the method for taking blood pressure?
standardise the environment when measuring blood pressure
- environment should be relaxed, quiet and warm
- the patient should be seated with their arm outstretched and supported
- patient should be seated and not talking for five minutes before taking the blood pressure
discard the initial value if there is a large (>10mmHg) difference between the first and subsequent readings and make further measurements.
How should the blood pressure of a person suspected of having postural hypotension be taken? How should the blood pressure of a person suspected of having hypertension be taken?
postural hypotension
- when blood pressure drops upon standing after sitting or standing for a period of time
- should measure blood pressure while the patient s standing
hypertension
- should take 2 additional readings at monthly intervals
When should treatment for hypertension be started?
treatment should only be initiated if ambulatory monitoring confirms hypertension
What is at risk of hypertension?
age
- hypertension os more prevalent as you age
ethnic group
- black people have higher prevalence and incidence of hypertension than white people
gender
- men are more likely to develop hypertension at an earlier age
- as age increases hypertension is more prevalent in women
What are the normal measurements of blood pressure?
systole and diastole
systolic = 90-120 mmHg
- optimal is less than 120 mmHg
- normal is less than 130 mmHg
diastolic = 60-80 mmHg
- optimal is less than 80 mmHg
- normal is less than 85 mmHg
What is diabetes mellitus?
Diabetes Mellitus is a chronic, progressive, lifelong condition
- characterised by chronic hyperglycaemia (high blood glucose levels) with disturbances of carbohydrate, fat and protein metabolism
What are the types of diabetes?
Type 1 diabetes (T1DM)
- results from destruction of the insulin producing pancreatic beta cells (in the islets of langerhans)
- generally affects younger non-obese people
Type 2 diabetes (T2DM)
- is caused by a combination of insulin resistance and defective beta cell function
- more prevalent as you age
How can diabetes be diagnosed?
diagnosis is made by checking blood glucose levels when fasting and at random
fasting (no calorie intake for last 8 hours)
- plasma glucose ≥ 7.0 mmol/L
random (without regard to time since last meal)
- plasma glucose ≥ 11.1 mmol/L
What is the method for testing for diabetes?
random pin-prick blood test
a person with a test result ≥ 11.1 mmol/l
- should be referred to their GP practice at the earliest opportunity for further tests
if levels are between 5.6 and 11.0 mmol/l
- a re-test should be offered using a fasting sample
- this is probably best done by the GP
a random test result of < 5.6 mmol/l
- indicates a low probability of diabetes.
What is high cholesterol a risk factor of?
atherosclerotic cardiovascular disease (CVD)
- plaque builds up inside your arteries
stroke
What transports cholesterol around the body? What are the different forms?
lipoproteins transport cholesterol around the body
low-density lipoprotein (LDL) - carries cholesterol from the liver to cells
high-density lipoprotein (HDL) – carries cholesterol from cells to the liver where it is broken down or excreted as waste.
When do problems arise with cholesterol?
when the body makes too much low density lipoproteins
- carries too much cholesterol to cells and it builds up
when intake of cholesterol exceeds the body’s ability to excrete/remove it
What are the normal and optimal levels of cholesterol within the body?
total cholesterol
LDL cholesterol
HDL cholesterol
total cholesterol
- optimal is less than 4 mmol/L
- minimum standard is less than 5 mmo/L
LDL cholesterol
- optimal is less than 2 mmol/L
- minimum standard is less than 3 mmo/L
HDL cholesterol
preferred value for men is more than 1 mmol/L
preferred value for men is more than 1.2 mmol/L
What is the method for taking a cholesterol test?
two or more cholesterol measurements need to be performed to establish a diagnosis of high blood cholesterol
to ensure a good blood sample you should follow a protocol that reduces contamination by fats from cosmetics, soaps, etc
What is the main class of drug used to treat high cholesterol levels?
statins
- atorvastatin
What is obesity? What are health consequences of obesity?
is defined as a body mass index (BMI) of 30Kg/m2 or more
- where a person’s BMI is defined as their weight in kilograms divided by the square of their height in metres
health consequences of obesity
- type 2 diabetes, high blood pressure, asthma, high cholesterol, atherosclerotic cardiovascular disease
What classifies as healthy weight, overweight and obese?
healthy weight = 18.5 - 24.9
overweight = 25 - 29.9
obese = 30+
What makes up the blood?
Blood is
Plasma (55%) = water, electrolytes, protein
Cells (45%) = erythrocytes, thrombocytes, leukocytes
What causes anaemia?
Insufficient Haemoglobin
- blood can’t carry enough oxygen from the lungs to the tissues to meet tissue needs
Inadequate iron absorption
- malabsorption or inadequate iron intake
Increased physiological demand
Blood loss
How can red blood cells indices/anaemia be tested for?
haemoglobin - Hb
- check the total amount of Hb in the blood
- anaemic should be less than 132g/L for M and less than 117 g/L for F
haematocrit - Hct
- check the volume of RBCs in the blood
- anaemic should be less than 40% for M and less than 36% for F
mean corpuscular haemoglobin concentration - MHC
- check the average Hb concentration in a RBC
- microcytic (smaller than normal so iron deficiency), normocytic, macrocytic (bigger than normal, vitamin B12 and folate deficient)
mean corpuscular volume - MCV
- check the average volume of a single RBC
mean corpuscular haemoglobin - MCH
- check the average mass/weight of each Hb per RBC
How can iron indices/anaemia be tested for?
serum ferritin = body’s storage of iron
- low Ferritin – iron deficiency
- increased serum ferritin – iron overload, alcoholism, inflammatory diseases
transferrin = protein that transports iron
- measured by TIBC (total iron binding capacity)
serum iron
- amount of iron bound to transferrin
transferrin saturation
- percentage of serum iron to TIBC
- 20-50%
What are indicators of anaemia?
microcytic
- decrease MCV = small red cells, MCV < 80 fl)
hypochromic
- reflects a decreased Hb content within the RBC
- is associated with decreased MCH and MCHC producing a hypochromic appearance on blood film)
serum iron decreased
serum ferritin decreased
TIBC increased
Transferrin saturation decreased
What are the symptoms of anaemia?
fatigue and faintness dyspnoea on exertion = breathlessness tachycardia = palpitation, fast heart rate headache confusion decreased mental acuity skin pallor
What are iron rich foods? What is the treatment for anaemia?
iron-rich food
- red meat, fish, eggs, baked beans, pulses (kidney beans and lentils and dried apricots)
oral administration of ferrous sulphate 200mg tds (three times a day)
- haemoglobin level should rise by about 20g/L every 3 weeks
- once the Hb level is within the normal range, iron replacement should continue for a further 3 months to replace the body’s iron stores
What are other causes of anaemia other than iron deficiency and Hb deficiency?
Folate and Vitamin B12 deficiency
- they cause macrocytic anaemia
Anaemia associated with chronic diseases – e.g. Renal failure, chronic infections, etc -normocytic
How can cholesterol be treated?
- while waiting for more tests and preventative measures
cardioprotective diet
- healthy diet high in fibre, fruit and vegetables and oily fish
- nuts, seeds, and legumes daily
- avoid frying = try to grill, steam, poach or bake instead.
Limit red and processed meat
Limit alcohol and added sugar intake
Limit full fat dairy products
