cmecde 241

 Clinical Skills for OSCEs

22 Station 10 Chest pain history

Family history

• Parents, siblings, and children. Ask specifically about heart disease, hypertension, and other

heritable cardiovascular risk factors.

Social history

• Employment.

• Housing.

• Hobbies.

After taking the history

• Ask the patient if there is anything else that he might add that you have forgotten to ask. This is

an excellent question to ask in clinical practice, and an even better one to ask in exams.

• Thank the patient.

• Summarise your findings and offer a differential diagnosis.

• State that you would like to examine the patient and possibly order some investigations, in

particular:

• ECG to look for or help rule out ischaemic heart disease.

• Blood tests including

– troponins to look for or help rule out myocardial infarction

– D-dimers for suggestion of a DVT/pulmonary embolism (a negative result excludes the

diagnosis but a positive result does not confirm it)

– inflammatory markers such as white cell count and CRP for suggestion of pneumonia

• Chest X-ray for signs of pneumonia or pneumothorax.

• CTPA or V/Q scan if the history is suggestive of a pulmonary embolism.

Conditions most likely to come up in a chest pain history station

Angina:

• Heavy retrosternal pain which may radiate into the neck or left arm

• Brought on by effort or emotion and relieved by rest and nitrates

• Risk factors for ischaemic heart disease are likely

• A family history of ischaemic heart disease is likely

Myocardial infarction (MI):

• Pain typically comes on over a few minutes

• Pain is similar to that of angina but is typically severe, long-lasting (> 20 minutes), and

unresponsive to nitrates

• Often associated with sweating, nausea, and breathlessness

• Risk factors for ischaemic heart disease are likely

• A family history of ischaemic heart disease is likely

Cardiovascular and respiratory medicine

Station 10 Chest pain history 23

Pleuritic pain:

• Sharp, stabbing, ‘catching’ pain

• May radiate to the back or shoulder

• Typically aggravated by deep breathing and coughing

• Can be caused by pleurisy which can occur with pneumonia, pulmonary embolus, and

pneumothorax, or by pericarditis which can occur post-MI, in viral infections, and in autoimmune

diseases

• Pleural pain is localised to one side of the chest and is not position dependent

• Pericardial pain is central and positional, aggravated by lying down and alleviated by sitting up or

leaning forward

• Dressler’s syndrome (post-MI syndrome) is characterised by pleuritic chest pain from pericarditis

accompanied by a low-grade fever, and can occur up to three months following an MI

Pulmonary embolus:

• Sharp, stabbing pain that is of sudden onset

• May be associated with shortness of breath, haemoptysis, and/or pleurisy

• Typically aggravated by deep breathing and coughing

• May be a history of recent surgery, prolonged bed rest, or long-haul travel

Gastro-oesophageal reflux disease:

• Retrosternal burning

• Clear relationship with food and alcohol, but no relationship with effort

• May be associated with odynophagia and nocturnal asthma

• Aggravated by lying down and alleviated by sitting up and by antacids such as Gaviscon or milk

Musculoskeletal complaint e.g. costochondritis:

• May be associated with a history of physical injury or unusual exertion

• Pain is aggravated by movement, but is not reliably alleviated by rest

• The site of the pain is tender to touch

Panic attack:

• Rapid onset of severe anxiety lasting for about 20–30 minutes

• Associated with chest tightness and hyperventilation

Aortic dissection:

• Sudden onset, sharp, tearing pain that is maximal at the time of onset

• Radiates to the back

If you cannot differentiate angina from gastro-oesophageal reflux disease and there are

no signs of ischaemia on the ECG, advise an exercise ECG stress test. If this is negative,

consider a therapeutic trial of an antacid or a nitrate.

Clinical Skills for OSCEs

24 Station 11

Cardiovascular risk assessment

Cardiovascular risk factors can usefully be divided into fixed (non-modifiable) and modifiable risk

factors. Fixed risk factorsinclude older age, male gender, family history, and a South Asian background.

Modifiable risk factors include hypertension, hyperlipidaemia, diabetes, smoking, alcohol, exercise,

and stress. Having one or more of these risk factors does not mean that a person is going to develop

cardiovascular disease, but merely that he is at increased probability of developing it. Conversely,

having no risk factors is not a guarantee that a person is not going to develop cardiovascular disease.

Before starting

• Introduce yourself to the patient.

• Confirm his name and date of birth.

• Explain that you are going to ask him some questionsto assess hisrisk of cardiovascular disease

(coronary heart disease, cerebrovascular disease, vascular disease) and obtain consent.

Remember to be tactful in your questioning, and to respond sensitively to the patient’s

ideas, concerns and expectations (ICE).

The risk assessment

If this information has not already been provided or disclosed, find out the patient’s reason for

attending. Then note or enquire about:

Fixed risk factors

1. Age and sex.

2. Ethnic background. People from a South Asian background are at a notably higher risk of

cardiovascular disease.

3. Past cardiovascular events, e.g. MI or stroke. If the patient has a history of past cardiovascular

events, you are assessing him for secondary rather than primary prevention.

4. Family history. Ask about a family history of cardiovascular disease and risk factors for

cardiovascular disease such as hypertension, hyperlipidaemia and diabetes mellitus.

Modifiable risk factors

5. Hypertension. If hypertensive, ask about latest blood pressure measurement, time since first

diagnosis, and any medication being taken.

6. Hyperlipidaemia. If hyperlipidaemic, ask about latest serum cholesterol level, time since first

diagnosis, and any medication being taken.

7. Diabetes mellitus. If diabetic, ask about medication being taken, level of diabetes control

being achieved, time since first diagnosis, and presence of complications.

8. Cigarette smoking. If a smoker or ex-smoker, ask about number of years spent smoking and

average number of cigarettes smoked per day. Does the patient also smoke roll-ups and cannabis? Does he use illicit drugs such as cocaine?

9. Alcohol. Ask about the number of units of alcohol consumed in a day and typical week. Note

that depending on the amount and type that is drunk, alcohol can be either protective or a

risk factor.

10. Diet. In particular, ask about fried food and takeaways.

11. Lack of exercise. Ask about amount of exercise taken in a day or week. Does the patient walk

to work or walk to the shops?

12. Stress. Ask about occupational history and home life.

Cardiovascular and respiratory medicine

Station 11 Cardiovascular risk assessment 25

Table 2. Desirable lipid levels

Total cholesterol < 5.0 mmol/l

LDL ‘bad’ cholesterol (fasting)  3.0 mmol/l

HDL ‘good’ cholesterol  1.2 mmol/l

Total cholesterol/HDL cholesterol < 4.5

Tryglycerides (fasting) < 1.5 mmol/l

NB. Patients at high risk of cardiovascular disease should aim

for even better than these figures.

After the assessment

• If you have time, assess the extent of any cardiovascular disease.

• Ask the patient if there is anything he would like to add that you may have forgotten to ask

about.

• Give him feedback on his cardiovascular risk (e.g. low, medium, high), and, if appropriate,

indicate a further course of action (e.g. further investigations or further appointment to discuss

reducing modifiable risk factors).

• Address any remaining concerns.

• State to the examiner that appropriate investigations include:

– BMI (should be between 18.5kg/m2 and 24.9kg/m2

)

– waist circumference (should be less than 102cm for men and 89cm for women)

– blood pressure (should be under 140/90mmHg)

– fasting blood glucose levels (should be under 6.0mmol/L)

– fasting lipid levels (see Table 2)

• Suggest calculating the patient’s 10-year cardiovascular risk score using the Framingham risk

equation, which takes into account a number of risk factors including gender, age, total cholesterol, HDL cholesterol, smoking status, and blood pressure.

• Indicate that the management of cardiovascular risk factors includes lifestyle modification and,

if appropriate, medical intervention (see Table 3).

Table 3. Management of cardiovascular disease

Lifestyle modification Medical intervention

Advise patient to:

• Stop smoking.

• Reduce alcohol intake (to 3–4 units/day

in men and 2–3 in women, and avoid

binges).

• Lose weight.

• Adopt a healthy diet: reduce saturated

fatty acids, trans-fatty acids and

cholesterol; increase fibre and omega-3

fatty acids, e.g. from fish.

• Take 30–60 minutes of exercise per day.

• Consider statin for secondary prevention

or for primary prevention if 10-year risk is

>20%.

• Consider anti-platelet drugs e.g. aspirin.

• Consider anti-hypertensive agents.

• If necessary, seek to optimise blood sugar

control.

Clinical Skills for OSCEs

26 Station 12

Blood pressure measurement

Before starting

• Introduce yourself to the patient.

• Confirm his name and date of birth.

• Explain the procedure and obtain his consent.

• Tell him that he might feel some discomfort as the cuff is inflated, and that the blood pressure

measurement may have to be repeated.

Avoid white coat hypertension by putting the patient at ease. Briefly discuss a nonthreatening subject, such as the patient’s journey to the clinic, or the weather.

The procedure

• Select an appropriately sized cuff and attach it to the BP machine. This is usually a standard cuff

in all but children and the obese.

• Position the BP machine so that it is roughly at the level of the patient’s heart.

• Position the measurement column/dial so that it is at eye level (avoids parallax error).

• Position the patient’s right arm so that it is horizontal at the level of the mid-sternum and free

from obstructive clothing.

• Locate the brachial artery at about 2 cm above the antecubital fossa.

• Apply the cuff to the arm, ensuring that the arterial point/arrow is over the brachial artery.

• Inflate the cuff to 20–30 mmHg higher than the estimated systolic blood pressure. You can estimate the systolic blood pressure by palpating the brachial or radial artery pulse and inflating

the cuff until you can no longer feel it.

• Place the stethoscope over the brachial artery pulse, ensuring that it does not touch the cuff.

• Reduce the pressure in the cuff at a rate of 2–3 mmHg per second.

– the first consistent Korotkov sounds indicate the systolic blood pressure

– the muffling and disappearance of the Korotkov sounds indicate the diastolic blood pressure

• Record the blood pressure as the systolic reading over the diastolic reading. Do not attempt

to ‘round off’ your readings; to an examiner’s ear, 144/88 usually rings more true than 140/90.

• If the blood pressure is higher than 140/90, indicate that you need to take a second reading

after giving the patient a one minute rest.

• In some situations, it may be appropriate to record the blood pressure in both arms (to investigate coarctation or dissection of the aorta), and also with the patient lying and standing (to

investigate for postural hypotension: a drop in BP on standing of ≥20mmHg).

After the procedure

• Ensure that the patient is comfortable.

• Tell the patient his blood pressure and explain its significance. Hypertension can only be confirmed by several blood pressure measurements taken over an extended period of time.

• Thank the patient.

• Document the blood pressure recording in the patient’s notes.

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General skills

Station 8 Intravenous drug injection 17

After the procedure

• Ensure that the patient is comfortable and ask him to notify a member of the healthcare team

if he notices any adverse effects (it may be necessary to monitor the patient).

• Ask him if he has any questions or concerns.

• Thank him.

• Sign the prescription chart and record the date, time, drug, dose, and injection site of the intravenous injection in the medical records.

• Indicate that you would have your checking colleague countersign it.

Clinical Skills for OSCEs

18 Station 9

Examination of a superficial mass and of lymph

nodes

Before starting

• Introduce yourself to the patient.

• Confirm his name and date of birth.

• If allowed, take a brief history from him, for example, onset, course, effect on everyday life.

• Explain the examination and obtain consent.

• Consider the need for a chaperone.

• Ask the patient to expose the lump completely; for example, by undoing the top button of his shirt.

• Position him appropriately and ensure that he is comfortable.

The examination (IPPA: Inspection, Palpation, Percussion, Auscultation)

• Inspect the patient from the end of the bed, looking for other lumps and any other signs.

• Inspect the lump and note its site, colour, and any changes to the overlying skin such as

inflammation or tethering. Note also the presence or absence of a punctum.

• Ask the patient if the lump is painful before you palpate it. Is the pain only brought on by palpation or is it a more constant pain?

• Wash and warm your hands.

• Assess the temperature of the lump with the back of your hand.

• Palpate the lump with the pads of your fingers; if possible, from behind the patient. Consider:

– number: solitary or multiple

– size: estimate length, width, and height, or use a ruler or measuring tape

– shape: spherical, ovoid, irregular, other

– edge: well or poorly defined

– surface: smooth or irregular

– consistency: soft, firm, hard, rubbery

– fluctuance: rest two fingers of your left hand on either side of the lump and press on the lump with

the index finger of your right hand: if your left hand fingers are displaced, the lump is fluctuant

– pulsatility: rest a finger of each hand on either side of the lump: if your fingers are displaced,

the lump is pulsatile

– mobility or fixation: consider the mobility of the lump in relation both to the overlying skin

and the underlying muscle

– compressibility and reducibility: press firmly on the lump to see if it disappears; if it immediately

reappears, it is compressible; if it only reappears upon standing or coughing, it is reducible

• Percuss the lump for dullness or resonance.

• Auscultate the lump for bruits or bowel sounds.

• Transilluminate the lump by holding it between the fingers of one hand and shining a pen torch to it

with the other. A bright red glow indicates fluid whereas a dull or absent glow suggests a solid mass.

• Examine the draining lymph nodes (see below), or indicate that you would do so.

After examining the lump

• Ensure that the patient is comfortable.

• Ask him if he has any questions or concerns.

• Thank him.

• Wash your hands.

• Summarise your findings and offer a differential diagnosis.

• If appropriate, suggest further investigations, e.g. fine needle aspirate cytology (FNAc), biopsy,

ultrasound, CT.

General skills

Station 9 Examination of a superficial mass and of lymph nodes 19

Lymph node examination

Head and neck

The patient should be sitting up and examined from behind. With the fingers of both hands, palpate

the submental, submandibular, parotid, and pre- and post-auricular nodes. Next palpate the anterior

and posterior cervical nodes and the occipital nodes.

Submental

Anterior cervical

Submandibular

Parotid

Preauricular

Posterior

auricular

Occipital

Posterior

cervical

Figure 3. Lymph nodes in the head and neck.

Upper body

• Palpate the supraclavicular and infraclavicular nodes on either side of the clavicle.

• Expose the right axilla by lifting and abducting the arm and supporting it at the wrist with

your right hand.

• With your left hand, palpate the following lymph node groups:

– the apical

– the anterior

– the posterior

– the nodes of the medial aspect of the humerus

• Now expose the left axilla by lifting and abducting the left arm and supporting it at the wrist

with your left hand.

• With your right hand, palpate the lymph node groups, as listed above.

Clinical Skills for OSCEs

20 Station 9 Examination of a superficial mass and of lymph nodes

Anterior

group

Apical

group

Posterior

group

Supraclavicular

and infraclavicular

groups

Figure 4. Lymph nodes of the upper body.

Lower body

Palpate the superficial inguinal nodes (horizontal and vertical), which lie below the inguinal ligament

and near the great saphenous vein respectively, then the popliteal node in the popliteal fossa.

Conditions most likely to come up in a lump examination station

Epidermoid (sebaceous) cyst:

• Results from obstruction of sebaceous gland.

• May be red, hot, and tender.

• Spherical, smooth.

• Attached to the skin but not to the

underlying muscle.

• May have a punctum which may exude a

cottage cheese discharge.

Fibroma:

• Common and benign fibrous tissue tumour.

• Skin-coloured and painless.

• Can be sessile or pedunculated, ‘hard’ or

‘soft’.

• Situated in the skin and so unattached to

underlying structures.

Lipoma:

• Common and benign soft tissue tumour.

• Skin-coloured and painless.

• Spherical, soft and sometimes fluctuant.

• Not attached to the skin and therefore

mobile and ‘slippery’.

Skin abscess:

• Collection of pus in the skin.

• Very likely to be red, hot, and tender.

• May be indurated.

21Cardiovascular and respiratory medicine

Station 10

Chest pain history

Before starting

• Introduce yourself to the patient.

• Confirm his name and date of birth.

• Explain that you are going to ask him some questions to uncover the nature of his chest pain,

and obtain his consent.

• Ensure that he is comfortable.

The history

• Name, age, occupation, and ethnic origin.

Presenting complaint and history of presenting complaint

• Ask about the nature of the chest pain. Use open questions and give the patient the time to

tell his story. Also remember to be empathetic: chest pain can be a very frightening experience.

• Elicit the patient’s ideas, concerns and expectations (ICE).

• As with any pain history, the mnemonic SOCRATES can help develop your differential diagnosis:

– Site: where exactly is the pain?

– Onset and progression: when did the pain start and how has it changed or evolved?

– Character: what type of pain is it (e.g. dull, sharp, or crushing)?

– Radiation: does the pain move anywhere (e.g. into the jaw, arm, or back)?

– Associated symptoms and signs: ask specifically aboutsweating, nausea and vomiting,shortness of breath, cough, haemoptysis, dizziness, and palpitations

– Timing and duration: does the pain occur at particular times of the day? How long does each

episode last?

– Exacerbating and alleviating factors: does anything make the pain better or worse (e.g. exercise, movement, deep breathing, coughing, cold air, large or spicy meals, alcohol, rest, GTN,

sitting up in bed)?

– Severity: “How would you rate the pain on a scale of 1 to 10, with 1 being no pain at all and 10

being the worst pain you have ever experienced?”

– effect on everyday life: ask in particular about exercise tolerance and sleep

• Ask about any previous episodes of chest pain.

Past medical history

• Current, past, and childhood illnesses.

• In particular, ask about risk factors: coronary heart disease, myocardial infarction, stroke, pneumonia, pulmonary embolism, deep vein thrombosis, hypertension, hyperlipidaemia, diabetes,

smoking, alcohol use, and recent long-haul travel.

• Recent trauma or injury.

• Surgery.

Drug history

• Prescribed medication, including the oral contraceptive pill if female.

• Over-the-counter medication.

• Illicit drugs.

• Allergies.

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Clinical Skills for OSCEs

14 Station 7

Intramuscular, subcutaneous, and intradermal

drug injection

Specifications: A model or skin pad in lieu of a patient.

Before starting

• Introduce yourself to the patient.

• Confirm his name and date of birth.

• Discuss the procedure and obtain consent.

• Ask the patient if he has any allergies and what happens when he develops a reaction.

• Gather the appropriate equipment.

The equipment

• Patient’s drug chart • Non-sterile gloves

• British National Formulary (BNF) • Alcohol steret

• Drug • Cotton wool

• Diluent (usually sterile water or saline) • Plaster

• Appropriately sized syringe (e.g. 1 or 2 ml) • Sharps box

• 21G (green) needle and 23G (blue) or 25G (orange) needle*

*Note that the colour scheme for needles is not the same as that for cannulae (see Station 4)

The procedure

• Consult the prescription chart and check:

– the identity of the patient

– the prescription: validity, drug, dose, diluent (if appropriate), route of administration, date

and time of administration

– drug allergies, anticoagulation

• Consult the BNF and check the form of the drug, whether it needs reconstituting, the type and

volume of diluent required, and the speed of administration.

• Check the name, dose and expiry date of the drug on the vial, and ask another member of the

healthcare team to countercheck them.

• Wash your hands and don the gloves.

• Attach a 21G needle to the syringe and draw up the correct volume of the drug, making sure to

tap out and expel any air. For a powder, inject the appropriate type and volume of diluent into

the ampoule and shake until the powder has dissolved.

• Dispose of the needle and attach a new 23G needle to the syringe for IM/SC administration or

a 25G needle for ID administration.

• Ask the patient to expose his upper arm or leg and ensure that the target muscle is completely

relaxed.

• Identify landmarks in an attempt to avoid injuring nerves and vessels.

• Clean the exposed site with an alcohol steret and allow it to dry.

• Warn the patient to expect a ‘sharp scratch’.

Intramuscular (IM) injection technique

• For older children and adults, the densest portion of the deltoid muscle (above the armpit and

below the acromion) is the preferred IM injection site. The gluteal muscle is best avoided as the

General skills

Station 7 Intramuscular, subcutaneous, and intradermal drug injection 15

needle may not reach the muscle and there is a risk of damage to the sciatic nerve, not to mention

the general embarrassment of the thing. In infants and toddlers, the vastus lateralis muscle in the

anterolateral aspect of the middle or upper thigh is the preferred IM injection site.

• With your free hand, slightly stretch the skin at the site of injection.

• Introduce the needle at a 90 degree angle to the patient’s skin in a quick, firm motion.

• Pull on the syringe’s plunger to ensure that you have not entered a blood vessel. If you aspirate

blood, you need to start again with a new needle, and at a different site.

• Slowly inject the drug and quickly remove the needle.

Subcutaneous (SC) injection technique

• Bunch the skin between thumb and forefinger, thereby lifting the adipose tissue from the

underlying muscle (‘tenting’).

• Insert the needle, bevel uppermost, at a 45 degree angle in a quick, firm motion. You are aiming

for the tip of the needle to be in the ‘tent’.

• Release the skin.

• Pull on the syringe’s plunger to ensure that you have not entered a blood vessel.

• Slowly inject the drug.

Intradermal (ID) injection technique

• Stretch the skin taut between thumb and forefinger.

• Hold the needle so that the bevel is uppermost.

• Insert the needle at a 15 degree angle, almost parallel to the skin.

• Ensure that the needle is visible beneath the surface of the epidermis.

• Slowly inject the drug.

• A visible (and uncomfortable) bleb should form. If not, immediately withdraw the needle and

start again – you may have inserted the needle too deeply.

After the procedure

• Immediately dispose of the needle in the sharps box.

• Apply gentle pressure over the injection site with some cotton wool (the patient may assist

with this).

• Ensure that the patient is comfortable.

• Ask him if he has any questions or concerns.

• Thank him.

• Sign the prescription chart and record the date, time, drug, dose, and injection site of the injection in the medical records.

Figure 2. Intramuscular, subcutaneous, and intradermal injection techniques.

Intramuscular Subcutaneous Intradermal

Epidermis

Adipose tissue

Dermis

Muscle

90° 45° 15°

Clinical Skills for OSCEs

16 Station 8

Intravenous drug injection

Specifications: Anatomical arm in lieu of a patient. This station is likely to require you to demonstrate

and/or talk through the administration of an intravenous (IV) drug with a needle and syringe. There may

be a cannula in situ, enabling the drug to be administered through the cannula.

Before starting

• Introduce yourself to the patient.

• Confirm his name and date of birth.

• Discuss the procedure and obtain consent.

• Ask the patient whether he has any allergies and what happens when he develops a reaction.

• Gather the appropriate equipment.

The equipment

• Patient’s drug chart • Non-sterile gloves

• British National Formulary (BNF) • Tourniquet

• Drug • Alcohol sterets

• Diluent (usually sterile water) • Cotton wool

• Appropriately sized syringes • Sharps box

• 21G (green) needle (×2)

The procedure

• Consult the prescription chart and check:

– the identity of the patient

– the prescription: validity, drug, dose, diluent (if appropriate), route of administration, date

and time of administration

– drug allergies

• Consult the BNF and check the form of the drug, whether it needs reconstituting, the type and

volume of diluent required, and the speed of administration.

• Check the name, dose and expiry date of the drug on the vial and the name and expiry date of

the diluent. Ask another member of the healthcare team to countercheck them.

• Wash your hands and don the gloves.

• Attach a 21G (green) needle to a syringe and draw up the correct volume of the diluent.

• Reconstitute the drug by injecting the diluent into the ampoule and shaking it until it is completely dissolved.

• Draw up the reconstituted drug into the same syringe, making sure to tap out and expel any air.

• Remove the needle and attach a new 21G needle to the syringe.

• Apply a tourniquet to the model arm and select a suitable vein.

• Clean the venepuncture site with an alcohol steret.

• Retract the skin with your non-dominant hand to stabilise the vein, tell the patient to expect a

‘sharp scratch’, and insert the needle into the vein until a flashback is seen.

• Undo the tourniquet.

• Administer the drug at the correct speed (too fast may cause adverse reactions such as emesis).

• Withdraw the needle and immediately dispose of it in the sharps box.

• Apply gentle pressure over the injection site using a piece of cotton wool.

• Remove the gloves.

cmecde 2052

 

• Remove the protective cap from the other end of the giving set.

• Squeeze and release the collecting chamber of the giving set until it is about half full.

General skills

Station 4 Cannulation and setting up a drip 9

• Open the regulating clamp and run fluid through the giving set to expel any air/bubbles.

• Close the regulating clamp.

• If using an extension ‘octopus’ connector, open and flush with normal saline so that no air

remains.

• Wash your hands (see Station 1) and follow the cannulation procedure above.

• Rather than capping the cannula immediately after removing the needle, connect the giving

set directly and flush with fluid from the bag.

• Apply the adhesive plaster or transparent film dressing to secure the cannula.

• Adjust the drip-rate (1 drop per second is equivalent to about 1 litre per 6 hours).

• Check that there is no swelling of the subcutaneous tissue i.e. that the line has not ‘tissued’.

• Tape the tubing to the arm.

After the procedure

• Discard clinical waste appropriately.

• Ensure that the patient is comfortable and inform him of possible complications (e.g. pain,

erythema).

• Thank the patient.

• Sign the fluid chart and record the date and time.

Examiner’s questions: complications of cannula insertion

• Infiltration of the subcutaneous tissue. • Phlebitis.

• Nerve damage. • Thrombophlebitis.

• Haematoma. • Septic thrombophlebitis.

• Embolism. • Local infection.

Clinical Skills for OSCEs

10 Station 5

Blood cultures

Before starting

• Introduce yourself to the patient, and confirm his name and date of birth.

• Explain the procedure and obtain his consent.

• Ask him which arm he prefers to have blood taken from.

• Ask him to expose this arm.

• Wash your hands.

• Gather the equipment in a clean tray.

The equipment

In a clean tray, gather:

• Aerobic and anaerobic blood culture bottles

• Winged collection set (or 18g needle and 20ml syringe)

• Apron

• Non-sterile or sterile gloves

• Disposable tourniquet

• Alcohol sterets (x2)

• Chlorhexidine sponge

• Sterile gauze

• Sharps bin

• For the blood culture bottles, check types (aerobic and anaerobic) and expiry dates, and ensure

that the broth is clear. Do not remove the barcodes.

Every effort to use aseptic technique should be made. If blood is being collected for other

tests, the blood culture sample should be collected first. Do not use existing peripheral lines

to obtain blood cultures. The most common skin contaminants include Staphyloccus

epidermidis, Corynebacterium spp., Propionibacterium spp., and Bacillus spp.

The procedure

• Decontaminate your hands.

• Position the patient so that his arm is fully extended. Ensure that he is comfortable.

• Select a vein by palpation: the bigger and straighter the better. The vein selected is most commonly the median cubital vein in the antecubital fossa.

• Release the tourniquet.

• Decontaminate your hands.

• Clean the venepucture site with the chlorhexidine sponge.

• Decontaminate your hands.

• Remove the flip tops from the culture bottles and disinfect the rubber caps each with a fresh

alcohol steret.

• Decontaminate your hands and don the apron and gloves.

• Warn the patient to expect a ‘sharp scratch’.

• Retract the skin to stabilise the vein and insert the butterfly needle into the vein.

• Fill each bottle with at least 10ml of blood, as per the markings on the bottle (let the vacuum in

the bottles do the job for you). Fill the aerobic bottle first to minimise the amount of air in the

anaerobic sample. If using a needle and syringe, collect at least 20ml of blood into the syringe

General skills

Station 5 Blood cultures 11

so as to inject a minimum of 10ml of blood into each bottle. (It is advised not to change needles

between drawing blood and injecting into culture bottles since the risk of needlestick injury

outweighs that of contamination of the sample with skin flora.)

• Release the tourniquet.

• Withdraw the needle and apply pressure to the puncture site.

• Unscrew the adaptor and immediately dispose of the needle in the sharps bin.

After the procedure

• Ensure that the patient is comfortable.

• Thank him.

• Dispose of clinical waste in a clinical waste bin.

• Decontaminate your hands.

• Label the bottles, including clinically relevant information e.g. the puncture site and any

antibiotics that the patient has been taking (ideally, blood cultures should be taken before the

administration of antibiotics; if not, they should be taken immediately before the next dose,

with the exception of children).

• Fill in a blood request form.

• Convey the samples to the microbiology laboratory without delay (or else incubate the bottles).

• Document the procedure.

Clinical Skills for OSCEs

12 Station 6

Blood transfusion

Specifications: This station requires you either to cannulate an anatomical arm and set up a blood

transfusion, or, more likely, simply to set up a blood transfusion. You may be instructed to talk through

parts of the procedure.

Before starting

• Introduce yourself to the patient.

• Confirm his name and date of birth.

• Explain the requirement for a blood transfusion, explain the risks, and obtain his consent.

• Ensure that baseline observations have been recorded (pulse rate, blood pressure, and

temperature).

Cannulation

See Station 4.

Blood transfusion

1. Sample collection

• Re-confirm the patient’s name and date of birth and check his identity bracelet.

• Extract 10 ml of blood into a pink tube (some hospitals may require two tubes for new patients).

• Immediately label the tube and request form with the patient’s identifying data: name, date of

birth, and hospital number.

• Fill out a blood transfusion form, specifying the total number of units required.

• Ensure that the tube reaches the laboratory promptly.

2. Blood transfusion prescription

• Prescribe the number of units of blood required in the intravenous infusion section of the

patient’s prescription chart. Each unit of blood should be prescribed separately and be administered over a period of 4 hours.

• If the patient is elderly or has a history of heart failure, consider prescribing furosemide (loop

diuretic) with the second and fourth units of blood.

• Arrange for the blood bag to be delivered. The blood transfusion must start within 30 minutes

of the blood leaving the blood refrigerator.

3. Checking procedures

Ask a registered nurse or another doctor to go through the following checking procedures with you:

A. Positively identify the patient by asking him for his name, date of birth, and address.

B. Confirm the patient’s identifying data and ensure that they match those on his identity bracelet,

case notes, prescription chart, and blood compatibility report.

C. Record the blood group and serial number on the unit of blood and make sure that they match

the blood group and serial number on the blood compatibility report and the blood compatibility label attached to the blood unit.

D. Check the expiry date on the unit of blood.

E. Inspect the blood bag for leaks or blood clots or discoloration.

General skills

Station 6 Blood transfusion 13

4. Blood administration

• Attach one end of the transfusion giving set to the blood bag and run it through to ensure that

any air in the tubing has been expelled. Note that a transfusion giving set has an integral filter

and is not the same as a standard fluid giving set.

• Attach the other end of the giving set to the IV cannula which should be a grey (16G), wide-bore

cannula (minimum pink/20G, or larger for resuscitation situations).

• Adjust the drip rate so that the unit of blood is administered over 4 hours. Because one unit of

blood is 300 ml, and because 15 drops are equivalent to about 1 ml, this amounts to about 19

drops per minute.

• Sign the prescription chart and the blood compatibility report recording the date and time the

transfusion was started. The prescription chart and blood compatibility report should also be

signed by your checking colleague.

5. Patient monitoring

• Record the patient’s pulse rate, blood pressure, and temperature at 0, 15, and 30 minutes, and

then hourly thereafter.

• Ensure that the nursing staff observe the patient for signs of adverse transfusion reactions such

as fever, tachycardia, hypotension, urticaria, nausea, chest pain, and breathlessness.

• Make an entry in the patient’s notes, specifying the reason for the transfusion, the rate of the

transfusion, the total number of units given, and any adverse transfusion reactions.

Examiner’s questions: complications of blood transfusion

Immune • Acute haemolytic reaction, (usually due to ABO incompatibility).

•  Delayed haemolytic reaction, (usually due to Rhesus, Kell, Duffy,

etc., incompatibility).

•  Non-haemolytic reactions such as febrile reactions, urticarial

reactions, and anaphylaxis.

Infectious • Hepatitis.

• HIV/AIDS.

• Other viral agents.

• Bacteria.

• Parasites.

Cardiovascular • Left ventricular failure from volume overload.

Complications of massive

transfusion (>10 U)

• Hypothermia.

• Coagulopathy (from dilution of platelets and clotting factors).

• Acid–base disturbances.

• Hyperkalaemia.

• Citrate toxicity (from additive in bag of packed red blood cells).

• Iron overload.

Other • Air embolism.

• Thrombophlebitis.