Haematology And Vascular Conditions Flashcards
What is anaemia
Low level of haemoglobin in the blood
What is haemoglobin
A protein found in red blood cells that is responsible for picking up oxygen in the lungs and transporting to to the the cells of the body
How is anaemia subdivided into three categories
Anaemia is initially subdivided into three main categories based on the size of the red blood cell (the MCV). These have different underlying causes:
- Microcytic anaemia (low MCV indicating small RBCs)
- Normocytic anaemia (normal MCV indicating normal sized RBCs)
- Macrocytic anaemia (large MCV indicating large RBCs)
What are the microcytic anaemia causes
T – Thalassaemia A – Anaemia of chronic disease I – Iron deficiency anaemia L – Lead poisoning S – Sideroblastic anaemia
What are the normocytic anaemia causes
A – Acute blood loss A – Anaemia of Chronic Disease A – Aplastic Anaemia H – Haemolytic Anaemia H – Hypothyroidism
What are the macrocytic anaemia causes
Macrocytic anaemia can be megaloblastic or normoblastic. Megaloblastic anaemia is the result of impaired DNA synthesis preventing the cell from dividing normally. Rather than dividing it keeps growing into a larger, abnormal cell. This is caused by a vitamin deficiency
Megaloblastic anaemia is caused by:
- B12 deficiency
- Folate deficiency
Normoblastic macrocytic anaemia is caused by:
- Alcohol
- Reticulocytosis (usually from haemolytic anaemia or blood loss)
- Hypothyroidism
- Liver disease
- Drugs such as azathioprine
What are the signs and symptoms of anaemia
There are many generic symptoms of anaemia:
- Tiredness
- Shortness of breath
- Headaches
- Dizziness
- Palpitations
- Worsening of other conditions such as angina, heart failure or peripheral vascular disease
There are symptoms specific to iron deficiency anaemia:
- Pica: describes dietary cravings for abnormal things such as dirt and can signify iron deficiency
- Hair loss: can indicate iron deficiency anaemia
Generic signs of anaemia:
- Pale skin
- Conjunctival pallor
- Tachycardia
- Raised respiratory rate
Signs of specific causes of anaemia:
- Koilonychia is spoon shaped nails and can indicate iron deficiency
- Angular chelitis can indicate iron deficiency
- Atrophic glossitis is a smooth tongue due to atrophy of the papillae and can indicate iron deficiency
- Brittle hair and nails can indicate iron deficiency
- Jaundice occurs in haemolytic anaemia
- Bone deformities occur in thalassaemia
- Oedema, hypertension and excoriations on the skin can indicate chronic kidney disease
How is anaemia investigated
Initial Investigations:
- Haemoglobin
- Mean Cell Volume (MCV)
- B12
- Folate
- Ferritin
- Blood film
Further Investigations:
- Oesophago-gastroduodenoscopy (OGD) and colonoscopy to investigate for a gastrointestinal cause of unexplained iron deficiency anaemia. This is done on an urgent cancer referral for suspected gastrointestinal cancer.
- Bone marrow biopsy may be required if the cause is unclear
What are the causes of iron deficient anaemia
Insufficient dietary iron
Iron requirements increase (for example in pregnancy)
Iron is being lost (for example slow bleeding from a colon cancer)
Inadequate iron absorption
How is iron deficient anaemia managed
Management involves treating the underlying cause and correcting the anaemia. The anaemia can be treated depending on the severity and symptoms with three methods, that range from fastest to slowest and most invasive to least invasive:
Blood transfusion. This will immediately correct the anaemia but not the underlying iron deficiency and also carries risks.
Iron infusion e.g. “cosmofer”. There is a very small risk of anaphylaxis but it quickly corrects the iron deficiency. It should be avoided during sepsis as iron “feeds” bacteria.
Oral iron e.g. ferrous sulfate 200mg three times daily. This slowly corrects the iron deficiency. Oral iron causes constipation and black coloured stools. It is unsuitable where malabsorption is the cause of the anaemia.
When correcting iron deficiency anaemia with iron you can expect the haemoglobin to rise by around 10 grams/litre per week.
What is an abdominal aortic aneurysm
AKA AAA
Refers to dilation of the abdominal aorta with a diameter of more than 3cm
Often patients first become aware of an aneurysm is when it ruptures, causing life-threatening bleeding into the abdominal cavity
Mortality of a ruptured AAA is ~80%
What are the risk factors for a AAA
Men are affected significantly more often and at a younger age than women Increased age Smoking Hypertension Family history Existing cardiovascular disease
What is the screening process for AAA
All men in England are offered a screening ultrasound scan at age 65 to detect asymptomatic AAA. Early detection of an AAA means preventative measures can stop it from expanding further or rupturing.
Women are not routinely offered screening, as they are at much lower risk. The NICE guidelines (2020) say a routine ultrasound can be considered in women aged over 70 with risk factors such as existing cardiovascular disease, COPD, family history, hypertension, hyperlipidaemia or smoking.
Patients with an aorta diameter above 3cm are referred to a vascular team (urgently if more than 5.5cm).
How do patients with an AAA present
Most patients are asymptomatic and often discovered on routine screening or when it ruptures
Other ways it can present include:
-Non-specific abdominal pain
-Pulsatile and expansile mass in the abdomen when palpated with both hands
-As an incidental finding on an abdominal x-ray, ultrasound or CT scan
How is a AAA diagnosed
Ultrasound: is the usual investigation for establishing the diagnosis
CT angiogram: gives a more detailed picture of the aneurysm and helps guide elective surgery to repair the aneurysm
How is a AAA classified
The severity of the aortic aneurysm depends on the size:
- Normal: less than 3cm
- Small aneurysm: 3 – 4.4cm
- Medium aneurysm: 4.5 – 5.4cm
- Large aneurysm: above 5.5cm
How is a AAA managed
Risk of progression of a AAA can be reduced by treating reversible risk factors:
- smoking cessation
- healthy diet and exercise
- optimising the management of hypertension, diabetes and hyperlipidaemia
Elective surgery:
- involves inserting an artificial graft into the section of the aorta affected by the aneurysm by:
- open repair via laparotomy
- end-vascular aneurysm repair (EVAR) using a stent inserted via the femoral arteries
How does a ruptured AAA present
Severe abdominal pain that may radiate to the back or groin
Haemodynamic instability (hypotension and tachycardia)
Pulsatile and expansile mass in the abdomen
Collapse
Loss of consciousness
How is a ruptured AAA managed
Surgical emergency requiring immediate involvement of experience seniors
Permissive hypotension refers to the strategy of aiming for a lower than normal blood pressure when performing fluid resuscitation because of the theory that increasing the blood pressure may increase blood loss
Haemodynamically unstable patients with a suspected AAA should be transferred directly to theatre. Surgical repair should not be delayed by getting imaging to confirm the diagnosis.
CT angiogram can be used to diagnose or exclude ruptured AAA in haemodynamically stable patients.
In patients with co-morbidities that make the prognosis with surgery very poor, a discussion needs to be had with senior doctors, the patient and their family about palliative care.
What are varicose veins
Distended superficial veins measuring more than 3mm in diameter, usually affecting the legs
What are reticular veins
Dilated blood vessels in the skin measuring less than 1-3mm in diameter
What is telangiectasia
Refers to dilated blood vessels in the skin measuring less than 1mm in diameter
Also known as spider veins or thread veins
How do varicose veins develop
Veins contain valves that only allow blood to flow in one direction, towards the heart. In the legs, as the muscles contract, they squeeze blood upwards against gravity. The valves prevent gravity from pulling the blood back into the feet. When the valves become incompetent, the blood is drawn downwards by gravity and pools in the veins and feet.
The deep and superficial veins are connected by vessels called the perforating veins (or perforators), which allow blood to flow from the superficial veins to the deep veins. When the valves are incompetent in these perforators, blood flows from the deep veins back into the superficial veins and overloads them. This leads to dilatation and engorgement of the superficial veins, forming varicose veins.
What are the risk factors for varicose veins
Increasing age
Family history
Female
Pregnancy
Obesity
Prolonged standing (e.g., occupations involving standing for long periods)
Deep vein thrombosis (causing damage to the valves)
