CT Contrast Flashcards
Where is contrast used
SBRT - small volume delineation
NSQH standard 4
- process for documentating patient history of medicine allergies and adverse drug reactions
- process for documentating adverse drug reactions experienced by patients during an episode of care
- Process for reporting adverse drug reactions experienced by patients to the therapeutic goods administration
What should happen in emergency situations
Check for early warning signs
Recognise problem and trigger response
Initiate action (communicate, CPR, address danger) and call for help
Assist when help arrives
IV contrast usefulness
Assists in tumour localisation
Specially in the abdomen as it also enhances soft tissue visualisation
Phases of contrast enhancement
Depends on pathology of interest
Some lesions can be hypovascular or hyper vascular compared to normal tissue
Peripheral IV injection - travels to right side of the heart, pulmonary circulation and left heart before reaching the central arterial system which travels to the rest of the organs .
Timing of arterial phase
35-40sec
Arteries will show optimal enhancement
Timing of hepatic or portal phase
70-80sec
Enhancement of portal and hepatic veins
Hepatic phase
Liver tissue is highlighted
Contrast flow rate
Depends on volume of contrast
Patient weight
Rate of flow of the volume fo the contrast
SI unit is ml/sec
Large volume administered = faster flow rate
Patient ineligibility criteria
Known allergy to contrast
Abnormal renal function
Diabetes managed with metformin
Types of adverse reactions
Anaphylactic, chemotoxic (organ specific), Vasovagal
Anaphylactoid
Mild - nasal congestion, sneezing, pruritis
Moderate - wheezing, dyspnoea, hypertension
Severe - arrhythmia, cardiac arrest, anaphylaxis
Chemotoxic
Nephrotoxicity, neurotoxicity, cariotoxicity
Patient risk factors
Congestive heart failure
Nephrotic syndrome
Dehydration
Multiple myeloma
Asthma
Hyperthyroidism
Pregnancy
Extremely anxious
Extravasating
Leakage of an intravenous drug from the vein into surrounding tissue
Very rare - small risk of injury is extravasating are greater than 100ml
Can cause swelling, tenderness.
Severe compartment syndrome, necrosis
What to do in case of extravasation
Immediate treatment
Remove cannula
Stop infusion
Elevate affected extremity
Apply hot pack with towel
Useful sites for contrast use
Lung
Oesophagus
Mediastinal nodes
Liver
Pancreas
Metastatic brain lesions
Types of contrast in CT
Iodine based non-ionic chemical
Pre-loaded syringes 100-125mL
Kept it in 37 degrees to maintain viscosity
Intravenous administration
Type - Omnipaque
Where does contrast excrete through
Renal route
Radiation oncologist role
Discuss CT planning site with planner
Contrast enhancement phases requested
Discuss cannualtion site with planner
Attach tubing to cannula
Start pressure injector
Monitor patient
Disconnect tubing from cannula
Flush line
RANZCR training guidelines
- trained in the recognition of contrast media reactions and procedures for treating these reactions and resuscitation procedures
Role of RNs
Remind patient about H2O
Renal function test complete
Resuscitation equipment
Patient education
Remove cannula 20min post contrast
CT simulation protocol
1st scan is planning data set
2nd scan is contrast data set
Mild, Moderate and Severe Contrast Reactions
Mild:
* flushing, nausea, pruritus, vomiting, headache and mild urticaria
* usually self-limited and resolve without specific treatment
Moderate:
* severe vomiting, marked urticaria, bronchospasm or other respiratory symptoms
Severe:
* hypovolaemic shock, respiratory arrest, cardiac arrest and convulsions
* very rare
