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Clinical Procedures - Computed Tomography (CT)
Indications
• Indications are manifold and too numerous to list.
Contraindications
• The standard radiation protection precautions apply. See separate topic
• The patient must be able to lie flat and still for the duration of the scan
• Examinations of the chest usually require the patient to hold their breath.
Technology
• The CT scanner houses an x-ray tube and rows of detectors which spin at 2-3 revolutions per second, creating a force of up to 25g
• As the patient is moved through the machine, spiral data is acquired which is then converted to 'slices' by the software.
Procedure
This depends on the part of the body examined and the indications for the examination.
• If indicated, the patient may be given oral contrast an hour or more before the examination
• The patient lies (usually supine) on the scanner table:
• Head-first for head and neck; feet-first for almost everything else
• 'Scout' views are acquired which are brief swipes across the area of interest. The resultant images are then used by the radiographer to set the parameters for the scan
• Most examinations involve IV iodinated contrast being given:
• This is usually delivered via an IV cannula by an automatic pump-injection device, controlled remotely by the radiographer
• Contrast may be hand-injected immediately before some scans
• Depending on the part of the body examined, the patient may be asked to hold their breath via speakers in the machine. Microphones within the scanner allow the staff in the control room to hear the patient
• The scan itself lasts no more than a couple of minutes. Time taken to transfer the patient onto the scanner and set up the IV injections will vary.
Risks
• IV contrast reactions including anaphylaxis and nephrotoxicity. IV contrast should not be given to patients with renal impairment unless in special circumstances. Check local guidance
• Extravasation of IV contrast (pain, swelling, erythema).
Indications
• Indications are manifold and too numerous to list.
Contraindications
• The standard radiation protection precautions apply. See separate topic
• The patient must be able to lie flat and still for the duration of the scan
• Examinations of the chest usually require the patient to hold their breath.
Technology
• The CT scanner houses an x-ray tube and rows of detectors which spin at 2-3 revolutions per second, creating a force of up to 25g
• As the patient is moved through the machine, spiral data is acquired which is then converted to 'slices' by the software.
Procedure
This depends on the part of the body examined and the indications for the examination.
• If indicated, the patient may be given oral contrast an hour or more before the examination
• The patient lies (usually supine) on the scanner table:
• Head-first for head and neck; feet-first for almost everything else
• 'Scout' views are acquired which are brief swipes across the area of interest. The resultant images are then used by the radiographer to set the parameters for the scan
• Most examinations involve IV iodinated contrast being given:
• This is usually delivered via an IV cannula by an automatic pump-injection device, controlled remotely by the radiographer
• Contrast may be hand-injected immediately before some scans
• Depending on the part of the body examined, the patient may be asked to hold their breath via speakers in the machine. Microphones within the scanner allow the staff in the control room to hear the patient
• The scan itself lasts no more than a couple of minutes. Time taken to transfer the patient onto the scanner and set up the IV injections will vary.
Risks
• IV contrast reactions including anaphylaxis and nephrotoxicity. IV contrast should not be given to patients with renal impairment unless in special circumstances. Check local guidance
• Extravasation of IV contrast (pain, swelling, erythema).
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Clinical Procedures – Magnetic Resonance Imaging (MRI)
Indications
• Indications are manifold and too numerous to list.
Contraindications
• As there is no ionizing radiation, radiation precautions do not apply
• D All ferromagnetic materials will be strongly attracted to the scanner creating missiles which may prove extremely dangerous. MRI-safe trolleys, resuscitation equipment, and wheelchairs must be employed
• D Implanted ferromagnetic devices, aneurysm clips, and retained foreign bodies (e.g. shrapnel or metallic fragments in the eyes) will also move towards the scanner potentially causing major injury
• D Although electronic pacemakers are not made of ferromagnetic material, they may be reset' or stop altogether
• A strict questionnaire is employed before anyone (staff or patient) is allowed near the magnet. If in doubt, access is denied
• Magnetic tape and credit cards may be 'wiped by the magnet
• D Many brands of mascara contain ferromagnetic filaments which may heat and cause burns to the eyelids
• D Caution should also be taken with tattoos some contain iron
• The patient must be able to lie flat and still for the duration of the scan.
Most scanners are relatively tight, larger patients may not fit.
Technology
• The MRI scanner houses a very large electromagnet which is always on
• Radiowaves are produced by the machine, which interact with hydrogen atoms in the patient. Radiowaves are, in turn, produced by the interaction with the hydrogen atoms and are detected by the machine which converts the data into images. The scanner has no moving parts
• The suite houses a Faraday cage preventing radiowaves getting in or out.
Procedure
• This depends on indications and the part of the body examined
• The patient lies on the scanner table. 'Coils' may be placed over the body-part of interest
• Most examinations do not involve IV contrast being given. If this is given, contrast containing gadolinium (Gd) is usually used:
• This is usually hand-injected immediately before the scan
• Depending on the part of the body examined, the patient may be asked to hold their breath via speakers in the machine
• The scan itself can last up to 40-50 minutes for some body parts.
Risks
• Nephrogenic systemic fibrosis (NSF): linked to gadolinium exposure in 2006. Symptoms may begin up to 3 months from exposure and may include pain, swelling, erythema, fibrosis of internal organs, and death. Patients with renal impairment are at greatest risk (no cases
recorded in those with GFR >60) and at least 9 hours of haemodialysis is required to remove it from the bloodstream.
• Metallic artefacts: twisting or movement of artefacts within the body
• Biological effects: the magnetic fields employed may induce voltages within the body. The most common effect is 'magnetophosphenes' or visual flashes seen by the patient as the optic nerve is stimulated.
Stimulation of other nerves and muscles may occur
• Tissue burns may occur if conducting loops (e.g. ECG leads) are in contact with skin
• Temperature: the oscillating voltages create tissue heating. Overall body temperature may rise by 0.3°C
• Noise: may reach up to 95dB. Headphones or earplugs are usually
worn
• Claustrophobia: experienced in up to 10% of patients.
Indications
• Indications are manifold and too numerous to list.
Contraindications
• As there is no ionizing radiation, radiation precautions do not apply
• D All ferromagnetic materials will be strongly attracted to the scanner creating missiles which may prove extremely dangerous. MRI-safe trolleys, resuscitation equipment, and wheelchairs must be employed
• D Implanted ferromagnetic devices, aneurysm clips, and retained foreign bodies (e.g. shrapnel or metallic fragments in the eyes) will also move towards the scanner potentially causing major injury
• D Although electronic pacemakers are not made of ferromagnetic material, they may be reset' or stop altogether
• A strict questionnaire is employed before anyone (staff or patient) is allowed near the magnet. If in doubt, access is denied
• Magnetic tape and credit cards may be 'wiped by the magnet
• D Many brands of mascara contain ferromagnetic filaments which may heat and cause burns to the eyelids
• D Caution should also be taken with tattoos some contain iron
• The patient must be able to lie flat and still for the duration of the scan.
Most scanners are relatively tight, larger patients may not fit.
Technology
• The MRI scanner houses a very large electromagnet which is always on
• Radiowaves are produced by the machine, which interact with hydrogen atoms in the patient. Radiowaves are, in turn, produced by the interaction with the hydrogen atoms and are detected by the machine which converts the data into images. The scanner has no moving parts
• The suite houses a Faraday cage preventing radiowaves getting in or out.
Procedure
• This depends on indications and the part of the body examined
• The patient lies on the scanner table. 'Coils' may be placed over the body-part of interest
• Most examinations do not involve IV contrast being given. If this is given, contrast containing gadolinium (Gd) is usually used:
• This is usually hand-injected immediately before the scan
• Depending on the part of the body examined, the patient may be asked to hold their breath via speakers in the machine
• The scan itself can last up to 40-50 minutes for some body parts.
Risks
• Nephrogenic systemic fibrosis (NSF): linked to gadolinium exposure in 2006. Symptoms may begin up to 3 months from exposure and may include pain, swelling, erythema, fibrosis of internal organs, and death. Patients with renal impairment are at greatest risk (no cases
recorded in those with GFR >60) and at least 9 hours of haemodialysis is required to remove it from the bloodstream.
• Metallic artefacts: twisting or movement of artefacts within the body
• Biological effects: the magnetic fields employed may induce voltages within the body. The most common effect is 'magnetophosphenes' or visual flashes seen by the patient as the optic nerve is stimulated.
Stimulation of other nerves and muscles may occur
• Tissue burns may occur if conducting loops (e.g. ECG leads) are in contact with skin
• Temperature: the oscillating voltages create tissue heating. Overall body temperature may rise by 0.3°C
• Noise: may reach up to 95dB. Headphones or earplugs are usually
worn
• Claustrophobia: experienced in up to 10% of patients.
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Clinical Procedures - Ultrasound (USS)
Indications
• Indications are manifold and too numerous to list. See making best use of a department of clinical radiology via www.rcr.ac.uk.
Contraindications
• For some examinations, the patient must be able to cooperate with the operator and a degree of mobility is often required
• Ultrasound becomes increasingly less diagnostic at greater depths.
Images of deeper structures in large individuals are often unobtainable and this should be borne in mind when considering who to refer.
Technology
• The ultrasound probe houses a piezoelectric crystal which both projects and receives high-frequency sound waves. Much like radar, the
'echos' are converted to images by the machine's software
• Ultrasound cannot image through gas and requires a semi-liquid 'gel' between the probe and skin surface for optimum imaging.
Procedure
• This depends on the part of the body examined and the indications for the examination:
• As ultrasound is a dynamic examination, any part of the patient that can be reached by the probe may be examined
• Time taken will vary depending on part of body examined, patient co-operation and complexity of the findings. Most examinations last between 5-20 minutes.
Risks
• There is no published evidence that ultrasound has ever directly caused any harm to a patient:
• The acoustic output of modern machines, however, is much greater than previously used
• Heating: some equipment can produce temperature rises of 4°C in bone. Most equipment in clinical use is unlikely to increase tissue temperature more than the 1.5°C which is considered 'safe
• Non-thermal hazard: ultrasound has been demonstrated to produce tiny gas pockets and bubbles in animal models. Neonatal lung is considered vulnerable to this but there is no evidence that diagnostic ultrasound can cause harm to other tissues
• Machines have a 'mechanical index' (MI) displayed on screen which acts as a guide to the operator.
Patient Preparation
Depends on the indication and body part being examined.
• Abdomen: patients are usually asked to fast for 6 hours prior to the examination. This ensures distension of the gallbladder and prevents the epigastric structures being obscured by overlying bowel gas
• Renal tract/pelvis: a full bladder is usually required. A full bladder creates an 'acoustic window', effectively pushing small bowel aside so that deeper structures (e.g. ovaries) may be seen.
Indications
• Indications are manifold and too numerous to list. See making best use of a department of clinical radiology via www.rcr.ac.uk.
Contraindications
• For some examinations, the patient must be able to cooperate with the operator and a degree of mobility is often required
• Ultrasound becomes increasingly less diagnostic at greater depths.
Images of deeper structures in large individuals are often unobtainable and this should be borne in mind when considering who to refer.
Technology
• The ultrasound probe houses a piezoelectric crystal which both projects and receives high-frequency sound waves. Much like radar, the
'echos' are converted to images by the machine's software
• Ultrasound cannot image through gas and requires a semi-liquid 'gel' between the probe and skin surface for optimum imaging.
Procedure
• This depends on the part of the body examined and the indications for the examination:
• As ultrasound is a dynamic examination, any part of the patient that can be reached by the probe may be examined
• Time taken will vary depending on part of body examined, patient co-operation and complexity of the findings. Most examinations last between 5-20 minutes.
Risks
• There is no published evidence that ultrasound has ever directly caused any harm to a patient:
• The acoustic output of modern machines, however, is much greater than previously used
• Heating: some equipment can produce temperature rises of 4°C in bone. Most equipment in clinical use is unlikely to increase tissue temperature more than the 1.5°C which is considered 'safe
• Non-thermal hazard: ultrasound has been demonstrated to produce tiny gas pockets and bubbles in animal models. Neonatal lung is considered vulnerable to this but there is no evidence that diagnostic ultrasound can cause harm to other tissues
• Machines have a 'mechanical index' (MI) displayed on screen which acts as a guide to the operator.
Patient Preparation
Depends on the indication and body part being examined.
• Abdomen: patients are usually asked to fast for 6 hours prior to the examination. This ensures distension of the gallbladder and prevents the epigastric structures being obscured by overlying bowel gas
• Renal tract/pelvis: a full bladder is usually required. A full bladder creates an 'acoustic window', effectively pushing small bowel aside so that deeper structures (e.g. ovaries) may be seen.
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Clinical Procedures - Bronchoscopy
Indications
• Diagnostic: histology/cytology in suspected lung malignancy, sample mediastinal lymphadenopathy, alveolar lavage (e.g. TB), transbronchial biopsy (e.g. diffuse lung disease)
• Therapeutic: placement of guidewire for local radiotherapy, direct treatment (e.g. diathermy to strictures):
• Placement of endobronchial stents and the removal of foreign bodies are usually accomplished at rigid bronchoscopy under general anaesthetic.
Contraindications
• Absolute: cardiovascular instability, life-threatening arrhythmia, severe hypoxaemia, respiratory failure with hypercapnia (unless intubated/
ventilated):
•Rigid bronchoscopy contraindications: unstable neck, severely ankylosed cervical spine, severely restricted temporomandibular joints
• Relative: uncooperative patient, recent MI, tracheal obstruction, un-correctable coagulopathy:
• Transbronchial biopsy with caution in uraemia, SVCO, pulmonary hypertension (risk of bleeding).
Procedure
Bronchoscopy is an endoscopic examination of the bronchial tree.
• Patient sits on the couch, leaning back comfortably
• Sedation (e.g. midazolam) may be given with monitoring of oxygen saturation. Atropine may also be given to decrease secretions
• Pharynx is anesthetized with aerosolized lidocaine
• Lubricated bronchoscope (about 6mm wide and 60cm long) is passed nasally or orally with use of a bite-block
• Brushings, biopsy or lavage (50-100mL saline) may be performed
• Duration varies but averages at about 20-30 minutes.
Risks
• Bleeding from a biopsy site and transient fever (10-15%)
• Medication effects: respiratory depression, hypotension, arrhythmias
• Topical anaesthesia: laryngospasm, bronchospasm, seizures, arrhythmias
• Minor laryngeal edema or injury with hoarseness, hypoxaemia in patients with compromised gas exchange (1-10%
• Mortality is 1 to 4/10,000 patients
• Transbronchial biopsy: pneumothorax (2-5%), significant haemorrhage (1%); death (12 in 10,000).
Patient Preparation
• Anticoagulant and antiplatelet therapy: stop for 3 days. Clopidogrel should be stopped for 5 days
• Blood tests: check clotting and full blood count
• Spirometry: perform if underlying lung disease
• Fasting: nil by mouth 2 hours before the procedure, no solids
4-6 hours before procedure.
Post-procedure
• Oxygen: supplemental oxygen for up to 1 hour
• Eating/drinking: drink after 1 hour. If no problems, can eat
• Chest radiography: only if dyspnoea or chest pain following biopsy
(10% risk of pneumothorax)
• Driving: if had midazolam or similar, not to drive or operate heavy machinery for the rest of the day.
Indications
• Diagnostic: histology/cytology in suspected lung malignancy, sample mediastinal lymphadenopathy, alveolar lavage (e.g. TB), transbronchial biopsy (e.g. diffuse lung disease)
• Therapeutic: placement of guidewire for local radiotherapy, direct treatment (e.g. diathermy to strictures):
• Placement of endobronchial stents and the removal of foreign bodies are usually accomplished at rigid bronchoscopy under general anaesthetic.
Contraindications
• Absolute: cardiovascular instability, life-threatening arrhythmia, severe hypoxaemia, respiratory failure with hypercapnia (unless intubated/
ventilated):
•Rigid bronchoscopy contraindications: unstable neck, severely ankylosed cervical spine, severely restricted temporomandibular joints
• Relative: uncooperative patient, recent MI, tracheal obstruction, un-correctable coagulopathy:
• Transbronchial biopsy with caution in uraemia, SVCO, pulmonary hypertension (risk of bleeding).
Procedure
Bronchoscopy is an endoscopic examination of the bronchial tree.
• Patient sits on the couch, leaning back comfortably
• Sedation (e.g. midazolam) may be given with monitoring of oxygen saturation. Atropine may also be given to decrease secretions
• Pharynx is anesthetized with aerosolized lidocaine
• Lubricated bronchoscope (about 6mm wide and 60cm long) is passed nasally or orally with use of a bite-block
• Brushings, biopsy or lavage (50-100mL saline) may be performed
• Duration varies but averages at about 20-30 minutes.
Risks
• Bleeding from a biopsy site and transient fever (10-15%)
• Medication effects: respiratory depression, hypotension, arrhythmias
• Topical anaesthesia: laryngospasm, bronchospasm, seizures, arrhythmias
• Minor laryngeal edema or injury with hoarseness, hypoxaemia in patients with compromised gas exchange (1-10%
• Mortality is 1 to 4/10,000 patients
• Transbronchial biopsy: pneumothorax (2-5%), significant haemorrhage (1%); death (12 in 10,000).
Patient Preparation
• Anticoagulant and antiplatelet therapy: stop for 3 days. Clopidogrel should be stopped for 5 days
• Blood tests: check clotting and full blood count
• Spirometry: perform if underlying lung disease
• Fasting: nil by mouth 2 hours before the procedure, no solids
4-6 hours before procedure.
Post-procedure
• Oxygen: supplemental oxygen for up to 1 hour
• Eating/drinking: drink after 1 hour. If no problems, can eat
• Chest radiography: only if dyspnoea or chest pain following biopsy
(10% risk of pneumothorax)
• Driving: if had midazolam or similar, not to drive or operate heavy machinery for the rest of the day.
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Clinical Procedures – Endoscopic Retrograde Cholangiopancreatography ( ERCP)
Indications
• Diagnostic: largely superseded by safer modalities such as endoscopic ultrasound and MRI/MRCP. Diagnostic indications include sphincter of Oddi dysfunction and primary sclerosing cholangitis
• Therapeutic: endoscopic sphincterotomy (biliary and pancreatic), removal of stones, dilation of strictures (e.g. primary sclerosing cholangitis), stent placement.
Contraindications
• Lack of informed consent, uncooperative patient, recent attack of pancreatitis, recent Ml, history of contrast anaphylaxis, severe cardiopulmonary disease, futility (anticipated short-term survival with no features of sepsis).
Procedure
An ERCP involves the passage of an endoscope into the duodenum. The endoscopist injects contrast medium through the ampulla of Vater via a catheter. Real-time fluoroscopy is used to visualize the pancreas and biliary tree. Selected images are taken.
• Dentures (if present) are removed
• Patient is given anaesthetic throat spray (lidocaine) and sometimes IV sedation/analgesia (e.g. midazolam, pethidine)
• Patient lies on the couch in a modified left lateral ('swimmer's") position with the left arm adducted and the right abducted. The endoscope is inserted as for OGD
• Under x-ray guidance, a polyethylene catheter is inserted into the biliary tree and contrast instilled to outline the pancreatic duct as well as the common bile duct and its tributaries
• Procedure time varies from 30-90 minutes.
Risks
• Pancreatitis (2-9% of procedures of which 10% of cases are mild-moderate). Serum amylase is temporarily raised in 70%
• Infection (ascending cholangitis, acute cholecystitis, infected pancreatic pseudocyst, liver abscess, endocarditis
• Bleeding, perforation of the oesophagus, duodenum, bile ducts
• Failure of gallstone retrieval
• Prolonged pancreatic stenting associated with stent occlusion, pancreatic duct obstruction, pseudocyst formation
• Basket impaction around a large gallstone (may require surgery).
Patient Preparation
• Blood tests: liver enzymes, platelets and clotting are checked prior to the procedure.
• Nil by mouth: 4 hours except in the case of an emergency.
• Antibiotic prophylaxis: recommended for:
• Patients in whom biliary decompression is unlikely to be achieved at a single procedure (e.g. dilatation of dominant stricture in multifocal sclerosing cholangitis or hilar cholangiocarcinoma)
• Consider also in patients with severe neutropenia (<0.5 × 109/L) and/ or profound immunocompromise.
Other Information
• © I sedation and analgesia is usually administered and the back of the throat is sprayed with local anaesthetic
• Hilar biliary obstruction demonstrated on MR or CT imaging may be more successfully stented using percutaneous transhepatic cholangiography (PTC) than ERCP
• Equipment allowing direct cholangioscopy (with the potential for sampling lesions) is becoming more widely available.
Indications
• Diagnostic: largely superseded by safer modalities such as endoscopic ultrasound and MRI/MRCP. Diagnostic indications include sphincter of Oddi dysfunction and primary sclerosing cholangitis
• Therapeutic: endoscopic sphincterotomy (biliary and pancreatic), removal of stones, dilation of strictures (e.g. primary sclerosing cholangitis), stent placement.
Contraindications
• Lack of informed consent, uncooperative patient, recent attack of pancreatitis, recent Ml, history of contrast anaphylaxis, severe cardiopulmonary disease, futility (anticipated short-term survival with no features of sepsis).
Procedure
An ERCP involves the passage of an endoscope into the duodenum. The endoscopist injects contrast medium through the ampulla of Vater via a catheter. Real-time fluoroscopy is used to visualize the pancreas and biliary tree. Selected images are taken.
• Dentures (if present) are removed
• Patient is given anaesthetic throat spray (lidocaine) and sometimes IV sedation/analgesia (e.g. midazolam, pethidine)
• Patient lies on the couch in a modified left lateral ('swimmer's") position with the left arm adducted and the right abducted. The endoscope is inserted as for OGD
• Under x-ray guidance, a polyethylene catheter is inserted into the biliary tree and contrast instilled to outline the pancreatic duct as well as the common bile duct and its tributaries
• Procedure time varies from 30-90 minutes.
Risks
• Pancreatitis (2-9% of procedures of which 10% of cases are mild-moderate). Serum amylase is temporarily raised in 70%
• Infection (ascending cholangitis, acute cholecystitis, infected pancreatic pseudocyst, liver abscess, endocarditis
• Bleeding, perforation of the oesophagus, duodenum, bile ducts
• Failure of gallstone retrieval
• Prolonged pancreatic stenting associated with stent occlusion, pancreatic duct obstruction, pseudocyst formation
• Basket impaction around a large gallstone (may require surgery).
Patient Preparation
• Blood tests: liver enzymes, platelets and clotting are checked prior to the procedure.
• Nil by mouth: 4 hours except in the case of an emergency.
• Antibiotic prophylaxis: recommended for:
• Patients in whom biliary decompression is unlikely to be achieved at a single procedure (e.g. dilatation of dominant stricture in multifocal sclerosing cholangitis or hilar cholangiocarcinoma)
• Consider also in patients with severe neutropenia (<0.5 × 109/L) and/ or profound immunocompromise.
Other Information
• © I sedation and analgesia is usually administered and the back of the throat is sprayed with local anaesthetic
• Hilar biliary obstruction demonstrated on MR or CT imaging may be more successfully stented using percutaneous transhepatic cholangiography (PTC) than ERCP
• Equipment allowing direct cholangioscopy (with the potential for sampling lesions) is becoming more widely available.
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Clinical Procedures - Coronary Angiography/Angioplasty
Indications
• Diagnostic: unstable or refractory angina, acute coronary syndrome, positive or inconclusive stress testing
• Emergency therapeutic: where possible, patients presenting with acute ST-elevation myocardial infarction should have primary coronary intervention rather than thrombolysis
• Elective therapeutic: suitable 'target lesion' identified on diagnostic coronary angiogram.
Contraindications
• Absolute: refusal of patient consent
• Relative: acute renal failure, pulmonary edema, known radiographic contrast allergy, uncontrolled hypertension, active gastrointestinal haemorrhage, acute stroke, and untreated coagulopathy.
Procedure
• Percutaneous access via a guide needle into a peripheral artery (most commonly the radial artery)
• Guide catheter is introduced, the tip is placed at the coronary ostium, radio-opaque contrast is injected, and real-time x-ray is used to visualize the blood flow through the coronary
• The coronary guidewire is inserted through the catheter into the coronary artery using x-ray guidance
• The guidewire tip is passed across the site of stenosis
• The balloon catheter is passed over the guidewire until the deflated balloon lies across the target lesion
• The balloon is then inflated and compresses the plaque and stretches the artery wall. A stent (wire mesh tube) can be inserted using a similar technique and be left in place maintaining the arterial lumen
• The guidewire, catheter, and sheath are carefully removed
• The patient should remain supine for 4 hours following the procedure unless an arterial closure device has been used.
Risks
• Minor: contrast allergy, vasovagal reaction, hemorrhage and hematoma at puncture site, thrombosis formation, false aneurysm, AV fistulation, pulmonary edema, and renal failure due to contrast nephropathy
• Major: limb ischaemia, coronary artery dissection, aortic dissection, ventricular perforation, air or atheroma embolism, ventricular arrhythmias failure of procedure, and need to proceed to coronary artery bypass graft
• Death (<1 in 1000).
Patient Preparation
• Pre-procedure check list: written consent, group and save, ECG, check full blood count/clotting/U&Es.
Other Information for Junior Doctors
• Coronary angioplasty is associated with increased thrombus formation (balloon inflation disrupts the intima, revealing prothrombotic cores of plaques), therefore antiplatelet therapy is necessary
• Patients will need to have long-term antiplatelet therapy; usually lifelong aspirin 75mg once daily, but they will also need clopidogrel 75mg once daily (see local guidelines: usually 3 months for bare metal stents and 12 months for drug-eluting stents or angioplasty after acute coronary syndrome)
• Patients with renal failure should be carefully considered. lodinated contrast can be nephrotoxic and renal decompensation may occur following coronary angiography/plasty. The risk can be minimized by hydration before and after the procedure. Renal function should be carefully monitored. Check local guidelines.
Indications
• Diagnostic: unstable or refractory angina, acute coronary syndrome, positive or inconclusive stress testing
• Emergency therapeutic: where possible, patients presenting with acute ST-elevation myocardial infarction should have primary coronary intervention rather than thrombolysis
• Elective therapeutic: suitable 'target lesion' identified on diagnostic coronary angiogram.
Contraindications
• Absolute: refusal of patient consent
• Relative: acute renal failure, pulmonary edema, known radiographic contrast allergy, uncontrolled hypertension, active gastrointestinal haemorrhage, acute stroke, and untreated coagulopathy.
Procedure
• Percutaneous access via a guide needle into a peripheral artery (most commonly the radial artery)
• Guide catheter is introduced, the tip is placed at the coronary ostium, radio-opaque contrast is injected, and real-time x-ray is used to visualize the blood flow through the coronary
• The coronary guidewire is inserted through the catheter into the coronary artery using x-ray guidance
• The guidewire tip is passed across the site of stenosis
• The balloon catheter is passed over the guidewire until the deflated balloon lies across the target lesion
• The balloon is then inflated and compresses the plaque and stretches the artery wall. A stent (wire mesh tube) can be inserted using a similar technique and be left in place maintaining the arterial lumen
• The guidewire, catheter, and sheath are carefully removed
• The patient should remain supine for 4 hours following the procedure unless an arterial closure device has been used.
Risks
• Minor: contrast allergy, vasovagal reaction, hemorrhage and hematoma at puncture site, thrombosis formation, false aneurysm, AV fistulation, pulmonary edema, and renal failure due to contrast nephropathy
• Major: limb ischaemia, coronary artery dissection, aortic dissection, ventricular perforation, air or atheroma embolism, ventricular arrhythmias failure of procedure, and need to proceed to coronary artery bypass graft
• Death (<1 in 1000).
Patient Preparation
• Pre-procedure check list: written consent, group and save, ECG, check full blood count/clotting/U&Es.
Other Information for Junior Doctors
• Coronary angioplasty is associated with increased thrombus formation (balloon inflation disrupts the intima, revealing prothrombotic cores of plaques), therefore antiplatelet therapy is necessary
• Patients will need to have long-term antiplatelet therapy; usually lifelong aspirin 75mg once daily, but they will also need clopidogrel 75mg once daily (see local guidelines: usually 3 months for bare metal stents and 12 months for drug-eluting stents or angioplasty after acute coronary syndrome)
• Patients with renal failure should be carefully considered. lodinated contrast can be nephrotoxic and renal decompensation may occur following coronary angiography/plasty. The risk can be minimized by hydration before and after the procedure. Renal function should be carefully monitored. Check local guidelines.
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Clinical Procedures - Echocardiography
Indications
• Myocardial infarction: assess wall motion and left ventricular function
• Valvular heart disease: assess competency and examine prostheses
• Embolic stroke: to exclude a cardiac embolic source
• Infective endocarditis: look for valvular vegetations
• Cardiomyopathy: assess ventricular dilatation/hypertrophy and function
• Congenital heart disease
• Pericardial disease
• Pericardial effusion: distribution of fluid and suitability for drainage
• Aortic disease: severity and site of aneurysm, dissection, or coarctation.
Contraindications
• The only contraindication is lack of patient consent or if the patient is unable to cooperate.
Technology
• Echocardiography is an ultrasound examination and uses the same technology (and machines) as general ultrasound. See separate topic
• Ultrasound becomes increasingly less diagnostic at greater depths and cannot see through lung. Images in large individuals are often suboptimal and the heart may not be seen at all in patients with hyperinflated lungs.
Procedure
• Time taken will vary depending on examinations performed and complexity of the findings. Most examinations last between 20-25 minutes
• With the patient lying on their left side, the operator uses a hand-held probe coated with gel to examine the heart usually via the anterior chest and epigastrium.
Risks
•There is no published evidence that ultrasound has ever directly caused any harm to a patient
• Heating: some equipment can produce temperature rises of 4°C in bone. Most equipment in clinical use is unlikely to increase tissue temperature more than the 1.5°C which is considered 'safe
• Non-thermal hazard: ultrasound has been demonstrated to produce tiny gas pockets and bubbles in animal models but there is no evidence that diagnostic ultrasound can cause harm to tissues other than neonatal lung.
Patient Preparation
• No preparation is required.
Other Information: Type of Echocardiography
Along with 2-dimensional transthoracic echocardiography, the following methods exist:
• 3D: uses computer software to produce a 3-dimensional image. Useful in left-ventricular functional assessment especially post-infarction
• 4D: 3D imaging with real-time movement captured
• TOE: transoesophageal echo is an invasive procedure. It requires written consent and is performed under sedation with local anaesthetic spray to the upper pharynx. The probe is covered, lubricated, and passed into the esophagus behind the heart. It is used to visualize the posterior cardiac structures. The investigation of choice for infective endocarditis
• Stress echo: used to assess myocardial ischaemia at 'rest and during
'stress'. Stress is induced by exercise or (more commonly) by an IV infusion of dobutamine in a controlled environment
• Bubble studies: used to assess for intracardiac shunts such as atrial or ventricular septal defects or patent foramen ovale. Air bubbles are agitated in a syringe and injected into a peripheral vein. The Valsalva manoeuvre is performed and, if a shunt exists, bubbles will be seen moving from the right side of the heart to the left.
Indications
• Myocardial infarction: assess wall motion and left ventricular function
• Valvular heart disease: assess competency and examine prostheses
• Embolic stroke: to exclude a cardiac embolic source
• Infective endocarditis: look for valvular vegetations
• Cardiomyopathy: assess ventricular dilatation/hypertrophy and function
• Congenital heart disease
• Pericardial disease
• Pericardial effusion: distribution of fluid and suitability for drainage
• Aortic disease: severity and site of aneurysm, dissection, or coarctation.
Contraindications
• The only contraindication is lack of patient consent or if the patient is unable to cooperate.
Technology
• Echocardiography is an ultrasound examination and uses the same technology (and machines) as general ultrasound. See separate topic
• Ultrasound becomes increasingly less diagnostic at greater depths and cannot see through lung. Images in large individuals are often suboptimal and the heart may not be seen at all in patients with hyperinflated lungs.
Procedure
• Time taken will vary depending on examinations performed and complexity of the findings. Most examinations last between 20-25 minutes
• With the patient lying on their left side, the operator uses a hand-held probe coated with gel to examine the heart usually via the anterior chest and epigastrium.
Risks
•There is no published evidence that ultrasound has ever directly caused any harm to a patient
• Heating: some equipment can produce temperature rises of 4°C in bone. Most equipment in clinical use is unlikely to increase tissue temperature more than the 1.5°C which is considered 'safe
• Non-thermal hazard: ultrasound has been demonstrated to produce tiny gas pockets and bubbles in animal models but there is no evidence that diagnostic ultrasound can cause harm to tissues other than neonatal lung.
Patient Preparation
• No preparation is required.
Other Information: Type of Echocardiography
Along with 2-dimensional transthoracic echocardiography, the following methods exist:
• 3D: uses computer software to produce a 3-dimensional image. Useful in left-ventricular functional assessment especially post-infarction
• 4D: 3D imaging with real-time movement captured
• TOE: transoesophageal echo is an invasive procedure. It requires written consent and is performed under sedation with local anaesthetic spray to the upper pharynx. The probe is covered, lubricated, and passed into the esophagus behind the heart. It is used to visualize the posterior cardiac structures. The investigation of choice for infective endocarditis
• Stress echo: used to assess myocardial ischaemia at 'rest and during
'stress'. Stress is induced by exercise or (more commonly) by an IV infusion of dobutamine in a controlled environment
• Bubble studies: used to assess for intracardiac shunts such as atrial or ventricular septal defects or patent foramen ovale. Air bubbles are agitated in a syringe and injected into a peripheral vein. The Valsalva manoeuvre is performed and, if a shunt exists, bubbles will be seen moving from the right side of the heart to the left.
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Clinical Procedures - Exercise Tolerance Testing (ETT)
Indications
• Assessment of chest pain in those with known coronary artery disease (there is no longer a role for ETT in patients presenting with chest pain who do not have a history of coronary artery disease)
• Assessment of haemodynamic response in those with known valvular disease who are asymptomatic
• Diagnosis of exertionally induced arrhythmias or syncope.
Contraindications
• Any undiagnosed or previously unknown murmur (patient should undergo echocardiogram first)
• Severe aortic stenosis (risk of syncope)
• Hypertrophic cardiomyopathy with significant outflow obstruction (risk of syncope)
• Severe hyper- or hypotension
• Unstable angina (should undergo coronary angiography)
• Known severe left main stem disease
• Untreated congestive cardiac failure
• Complete heart block
• Aortic aneurysm
• Acute myocarditis or pericarditis
• Any recent pyrexial or 'flu-like' illness.
Procedure
• ECG electrodes are put on the patient's chest and a sphygmomanometer cuff on an arm
• The patient is asked to walk on a treadmill connected to the computer whilst their ECG, blood pressure, and heart rate are monitored. The speed and incline of the treadmill increase according to set protocols:
• Bruce protocol: for assessment of physically fit and stable patients with suspected coronary artery disease, 7 stages starting at a 10% gradient at 1.7mph and increasing to 22% gradient and 6mph
• Modified Bruce protocol: used in elderly patients or those who have been stabilized after a suspected episode of unstable angina.
Starts at 1.7mph and 0% gradient and increases the gradient slowly to 10%
• Termination of the test depends on the results seen (see box).
Risks
• Risks are those associated with exercise and include:
• Arrhythmia, cardiac ischaemia, myocardial infarction, syncope.
Patient Preparation
• No specific preparation is required. Patients are asked not to eat or drink for 3 hours prior to the test
• Comfortable clothing and shoes should be worn.
Indications for termination of procedure
• Patient requests to stop
• Symptoms: fatigue, angina, dizziness, significant breathlessness
• Signs: drop in oxygen saturations <94%, target heart rate achieved, hypotension during exercise (e.g. BP <100mmg), significant hypertension (e.g. BP >200mmHg)
• ECG: any atrial or ventricular arrhythmia, frequent ventricular ectopics, new AV or bundle branch block, ST segment shift >1mm.
Causes of false positive results or low specificity
• Often due to difficulty interpreting results as result of resting ST segment abnormalities:
•Wolf-Parkinson-White syndrome, left bundle branch block, atrial fibrillation, left ventricular hypertrophy, digoxin therapy, hyperventilation, biochemical electrolyte abnormalities (e.g. hypo- or hyperkalaemia), cardiomyopathies, left ventricular outflow obstruction
Beta-blocker therapy prevents the appropriate heart rate/blood
pressure response during testing.
Indications
• Assessment of chest pain in those with known coronary artery disease (there is no longer a role for ETT in patients presenting with chest pain who do not have a history of coronary artery disease)
• Assessment of haemodynamic response in those with known valvular disease who are asymptomatic
• Diagnosis of exertionally induced arrhythmias or syncope.
Contraindications
• Any undiagnosed or previously unknown murmur (patient should undergo echocardiogram first)
• Severe aortic stenosis (risk of syncope)
• Hypertrophic cardiomyopathy with significant outflow obstruction (risk of syncope)
• Severe hyper- or hypotension
• Unstable angina (should undergo coronary angiography)
• Known severe left main stem disease
• Untreated congestive cardiac failure
• Complete heart block
• Aortic aneurysm
• Acute myocarditis or pericarditis
• Any recent pyrexial or 'flu-like' illness.
Procedure
• ECG electrodes are put on the patient's chest and a sphygmomanometer cuff on an arm
• The patient is asked to walk on a treadmill connected to the computer whilst their ECG, blood pressure, and heart rate are monitored. The speed and incline of the treadmill increase according to set protocols:
• Bruce protocol: for assessment of physically fit and stable patients with suspected coronary artery disease, 7 stages starting at a 10% gradient at 1.7mph and increasing to 22% gradient and 6mph
• Modified Bruce protocol: used in elderly patients or those who have been stabilized after a suspected episode of unstable angina.
Starts at 1.7mph and 0% gradient and increases the gradient slowly to 10%
• Termination of the test depends on the results seen (see box).
Risks
• Risks are those associated with exercise and include:
• Arrhythmia, cardiac ischaemia, myocardial infarction, syncope.
Patient Preparation
• No specific preparation is required. Patients are asked not to eat or drink for 3 hours prior to the test
• Comfortable clothing and shoes should be worn.
Indications for termination of procedure
• Patient requests to stop
• Symptoms: fatigue, angina, dizziness, significant breathlessness
• Signs: drop in oxygen saturations <94%, target heart rate achieved, hypotension during exercise (e.g. BP <100mmg), significant hypertension (e.g. BP >200mmHg)
• ECG: any atrial or ventricular arrhythmia, frequent ventricular ectopics, new AV or bundle branch block, ST segment shift >1mm.
Causes of false positive results or low specificity
• Often due to difficulty interpreting results as result of resting ST segment abnormalities:
•Wolf-Parkinson-White syndrome, left bundle branch block, atrial fibrillation, left ventricular hypertrophy, digoxin therapy, hyperventilation, biochemical electrolyte abnormalities (e.g. hypo- or hyperkalaemia), cardiomyopathies, left ventricular outflow obstruction
Beta-blocker therapy prevents the appropriate heart rate/blood
pressure response during testing.
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Clinical Procedures - Transferring a Patient Using a Hoist
Limited input from patient. Use this technique to transfer patients who are unable to weight bear, sit up in the bed, or use a bedpan.
Equipment
• Hoist
• Sling: single-patient use (disposable).
Procedure
• D There should be at least 2 handlers. Agree who will give commands:
• Check care plan regarding patient's suitability for hoist usage
• Before getting equipment, ensure manoeuvre is explained to patient
• Select appropriate sling: small, medium, or large
• Ensure hoist and sling are compatible
• Check hoist is able to take patient's weight: most are able to take up to 25 stones (170kg)
• Ensure issues around patient's privacy and dignity are appropriately addressed
• Check bed is at waist height to prevent staff injuries
• Staff stand either side of bed facing each other
• © Check brakes on bed secure
• Patient should be rolled to one side of bed:
•Encourage patient to do so without staff assistance if capable
• Lay the hoist sling on the bed
• Roll the patient to other side of the bed:
• Sling should now be in a position from patient's head to thigh
• Place the loops at shoulder end of sling on arm of hoist
• Pass the thigh-end loops through each other, then place on arm of hoist:
• D Ensure the loops are correctly positioned before moving
. 1 handler should now manage the controls of the hoist.
• Second handler lowers patient's bed, then moves behind the patient/hoist, ready to guide them into the chair
• Move patient back with hoist
• Second handler gently guides patient into the chair whilst they are
lowered
• Once patient is in chair, disconnect loops from hoist
• Remove sling from beneath lower legs of patient.
Procedures Tips
• Ensure sufficient time available to safely complete the manoeuvre
• Check bed area for any furniture/equipment that could be moved (e.g.
trailing wires)
• Always check items such as IV fluids, catheters, and drains are safe and unlikely to be caught in hoist or pulled out during procedure
• Check with qualified staff/physiotherapists regarding any changes in the patient's condition prior to manoeuvre. Transfer may be inadvisable
• Staff should wear suitable (preferably low-heel) footwear and non-restrictive clothing
• Hoist should only be used to transfer patients short distances (bed-side manoeuvres only)
• Ensure hoist is fully charged before commencing manoeuvre
• Ensure the brakes of the hoist are off. This will allow the hoist to find its own centre of gravity.
Risks
• Potential injuries to patient or staff arising from trailing leads, drains, etc.
• Disconnection of equipment during manoeuvre:
• Watch out for IV pumps, syringe drivers, catheters.
Documentation
• All patients should have assessments carried out within 24 hours of admission
• Care plan should be maintained/consulted as appropriate
• If there are any issues with equipment or manoeuvre, advise nurse in charge, document in notes, and complete an appropriate incident form
Limited input from patient. Use this technique to transfer patients who are unable to weight bear, sit up in the bed, or use a bedpan.
Equipment
• Hoist
• Sling: single-patient use (disposable).
Procedure
• D There should be at least 2 handlers. Agree who will give commands:
• Check care plan regarding patient's suitability for hoist usage
• Before getting equipment, ensure manoeuvre is explained to patient
• Select appropriate sling: small, medium, or large
• Ensure hoist and sling are compatible
• Check hoist is able to take patient's weight: most are able to take up to 25 stones (170kg)
• Ensure issues around patient's privacy and dignity are appropriately addressed
• Check bed is at waist height to prevent staff injuries
• Staff stand either side of bed facing each other
• © Check brakes on bed secure
• Patient should be rolled to one side of bed:
•Encourage patient to do so without staff assistance if capable
• Lay the hoist sling on the bed
• Roll the patient to other side of the bed:
• Sling should now be in a position from patient's head to thigh
• Place the loops at shoulder end of sling on arm of hoist
• Pass the thigh-end loops through each other, then place on arm of hoist:
• D Ensure the loops are correctly positioned before moving
. 1 handler should now manage the controls of the hoist.
• Second handler lowers patient's bed, then moves behind the patient/hoist, ready to guide them into the chair
• Move patient back with hoist
• Second handler gently guides patient into the chair whilst they are
lowered
• Once patient is in chair, disconnect loops from hoist
• Remove sling from beneath lower legs of patient.
Procedures Tips
• Ensure sufficient time available to safely complete the manoeuvre
• Check bed area for any furniture/equipment that could be moved (e.g.
trailing wires)
• Always check items such as IV fluids, catheters, and drains are safe and unlikely to be caught in hoist or pulled out during procedure
• Check with qualified staff/physiotherapists regarding any changes in the patient's condition prior to manoeuvre. Transfer may be inadvisable
• Staff should wear suitable (preferably low-heel) footwear and non-restrictive clothing
• Hoist should only be used to transfer patients short distances (bed-side manoeuvres only)
• Ensure hoist is fully charged before commencing manoeuvre
• Ensure the brakes of the hoist are off. This will allow the hoist to find its own centre of gravity.
Risks
• Potential injuries to patient or staff arising from trailing leads, drains, etc.
• Disconnection of equipment during manoeuvre:
• Watch out for IV pumps, syringe drivers, catheters.
Documentation
• All patients should have assessments carried out within 24 hours of admission
• Care plan should be maintained/consulted as appropriate
• If there are any issues with equipment or manoeuvre, advise nurse in charge, document in notes, and complete an appropriate incident form
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Clinical Procedures - Transferring a Patient Laterally Using a Transfer Board
No input from patient. Use this technique to transfer patients who are unable to move themselves.
Equipment
• Patient transfer board or 'Patslide®
Procedure
• There should be at least 3 handlers. Agree who will give commands
• Open transfer board (if folded) and place on bed/trolley you plan to transfer patient to
• Explain the manoeuvre to the patient
• Place destination bed/trolley alongside origin bed/trolley:
• Ensure there is only a minimal gap between the beds/ trolley involved
• Check bed is at waist height to prevent staff injuries
• Staff stand either side of bed/trolley facing each other, 2 people on the 'destination' side and 1 on the other
• Check brakes on bed and trolley secure
• Staff at the patient's bedside to lean over patient and grip bed sheet as close to the patient's body as possible with both hands and roll the patient towards them
• Staff at the bed/trolley onto which patient is to be transferred, put transfer board onto patient's bed/trolley
• Staff at bed-side allow patient to roll back onto board (which should be under the bed sheet)
• On command of 'Ready, Steady, Move'
• Handlers push and pull patient gently across on transfer board, dependent upon their position:
• Staff should ensure their arms remain straight and they do not lean forward, bending at the waist
• Once patient is transferred, ensure sheets and blankets are comfortably in place
• Bed rails should be put into place as appropriate
Procedure Tips
• Do not rush. Ensure sufficient time is available to safely complete the
manoeuvre
• Ensure the patient and handlers are fully informed regarding steps of the manoeuvre
• Check bed area for any furniture/equipment that could be moved
• Always check IV fluids, catheters, drains, etc. are safe and unlikely to be caught or pulled out during procedure
• Move any attachments onto transferring bed/trolley prior to the move
• Check with qualified staff/physiotherapists regarding any changes in the patient's condition prior to manoeuvre
• Staff should wear suitable (preferably low-heel) footwear and non-restrictive clothing
• Check with ward staff that patient can be laid flat
• If nasogastrically-fed, ensure it is switched off to prevent patient aspirating
• Do not climb onto the bed/trolley. There is a high risk of injury to the handler
Ensure both surfaces are the same height, making the manoeuvre
both easier and more comfortable for the patient.
Risks
• Potential injuries to patient/staff arising from trailing leads and drains
• Disconnection of equipment during manoeuvre
• If the gap between the beds/trolley is too wide, patient may fall through!
Documentation
• All patients should have assessments carried out within 24 hours of admission. Care plan to be maintained/consulted as appropriate
• Any issues or problems with equipment or manoeuvre should be conveyed to the nurse in charge, documented in the notes, and an appropriate incident form completed.
No input from patient. Use this technique to transfer patients who are unable to move themselves.
Equipment
• Patient transfer board or 'Patslide®
Procedure
• There should be at least 3 handlers. Agree who will give commands
• Open transfer board (if folded) and place on bed/trolley you plan to transfer patient to
• Explain the manoeuvre to the patient
• Place destination bed/trolley alongside origin bed/trolley:
• Ensure there is only a minimal gap between the beds/ trolley involved
• Check bed is at waist height to prevent staff injuries
• Staff stand either side of bed/trolley facing each other, 2 people on the 'destination' side and 1 on the other
• Check brakes on bed and trolley secure
• Staff at the patient's bedside to lean over patient and grip bed sheet as close to the patient's body as possible with both hands and roll the patient towards them
• Staff at the bed/trolley onto which patient is to be transferred, put transfer board onto patient's bed/trolley
• Staff at bed-side allow patient to roll back onto board (which should be under the bed sheet)
• On command of 'Ready, Steady, Move'
• Handlers push and pull patient gently across on transfer board, dependent upon their position:
• Staff should ensure their arms remain straight and they do not lean forward, bending at the waist
• Once patient is transferred, ensure sheets and blankets are comfortably in place
• Bed rails should be put into place as appropriate
Procedure Tips
• Do not rush. Ensure sufficient time is available to safely complete the
manoeuvre
• Ensure the patient and handlers are fully informed regarding steps of the manoeuvre
• Check bed area for any furniture/equipment that could be moved
• Always check IV fluids, catheters, drains, etc. are safe and unlikely to be caught or pulled out during procedure
• Move any attachments onto transferring bed/trolley prior to the move
• Check with qualified staff/physiotherapists regarding any changes in the patient's condition prior to manoeuvre
• Staff should wear suitable (preferably low-heel) footwear and non-restrictive clothing
• Check with ward staff that patient can be laid flat
• If nasogastrically-fed, ensure it is switched off to prevent patient aspirating
• Do not climb onto the bed/trolley. There is a high risk of injury to the handler
Ensure both surfaces are the same height, making the manoeuvre
both easier and more comfortable for the patient.
Risks
• Potential injuries to patient/staff arising from trailing leads and drains
• Disconnection of equipment during manoeuvre
• If the gap between the beds/trolley is too wide, patient may fall through!
Documentation
• All patients should have assessments carried out within 24 hours of admission. Care plan to be maintained/consulted as appropriate
• Any issues or problems with equipment or manoeuvre should be conveyed to the nurse in charge, documented in the notes, and an appropriate incident form completed.
