5.2 Contrast Agents Part 2 Flashcards
a very small percentage less than ____ of the iodinated CM given to a mother will be excreted into breast milk and absorbed by the infant
1%
one of the most widely used and one of the safest of all medications
Iodinated contrast agents
are extremely rare in both HOCM and LOCM estimated at 0.9 per 100,000 (<0.001%)
Fatal reactions
Mechanisms of Adverse Reactions
- Contrast Reaction
- Subjective Effects
all undesired effects including the many subjective side effects experienced to some degree by most patients to whom contrast is administered
Contrast Reaction
feeling of heat, nausea and mild flushing
Subjective Effects
2 Categories of Reactions
- Chemotoxic Reactions
2. Idiosyncratic Reactions
result from the physiochemical properties of the contrast media, the dose, and speed of infection
Chemotoxic Reactions
all hemodynamic (blood circulation) disturbances and injuries to organs
Chemotoxic Reactions
Chemotoxic Reactions examples
Contrast-induced nephropathy
includes all other reactions
Idiosyncratic Reactions
largely unpredictable
Idiosyncratic Reactions
most often occur within 1 hour of CM administration and are not related to the dose
Idiosyncratic Reactions
symptoms resemble allergic (or anaphylactic) and are therefore, often called “allergic-like” or “anaphylactoid” reactions
Idiosyncratic Reactions
risk of recurrent reaction in a patient with a prior reaction:
HOCM - 16% to 35%
LOCM - 7%
Common side effects:
“Less common when LOCM is used”
- Nausea
- Vomiting
- Altered taste (often described as metallic)
- Perspiration
- Warmth
- Flushing
- Anxiety
Classifications of Idiosyncratic Reactions
- Mild
- Moderate
- Severe
short duration and self-limiting
Mild
monitor patient at least 20-30 mins (M-S)
Mild
- Cough
- Itching
- Pallor (pale)
- Rash (hives)
- Nasal stiffness
- Minimal swelling in the eyes and face
- Facial rash
Mild
not immediately life threatening
Moderate
- Respiratory difficulties (bronchospasm, dyspnea, wheezing, laryngeal edema)
- Pulse change
- Hypertension
- Hypotension (leg elevation)
Moderate
potentially/immediately life-threatening
Severe
- Substantial respiratory distress
- Unresponsiveness
- Convulsions
- Clinically-manifested arrhythmias
- Cardiopulmonary arrest
Severe
Treatment
ABC
Airway Assessment, Breathing and Circulation
Treatment is Followed by
ACLS
Advanced Cardiac Life Support Treatment
Majority of idiosyncratic adverse side effects are mild, non-life-threatening events that require only ____
observation, reassurance and support
HOCM percentage of side effects
5 to 12% (Mild-98% to 99%)
The Radiographer may assist in reducing anxiety in the following ways:
- Assessment of the patient’s understanding of the procedure
- Informing the patient in detail concerning how the examination will proceed
- Explanation of the expected side effects and assurance that these are not unusual
- Allowing the patient to express feelings of anxiety and obtaining patient feedback to ascertain his complete understanding of the procedure
Patient Assessment Prior to Administration of Contrast Medium (1)
- Patient’s age
- History of impaired hepatic function
- History of impaired renal function
- History of allergic or anaphylactic reactions
- History of thyroid disease
- Last menstrual period and possible pregnancy
- Nursing mother
- Sensitivity to aspirin
Patient Assessment Prior to Administration of Contrast Medium (2)
- History of diabetes mellitus
- History of sickle cell disease
- History of hypertension
- History of pheochromocytoma
- History of seizures
- Medication history
- History of previous reactions to medications or contrast agents
- Allergy to seafood
Incidence and Risk Factors for Idiosyncratic Reactions
- Previous contrast medium reaction
- Asthma
- Allergies
- Drugs
Prevention of Acute Idiosyncratic Reactions
- Use LOCM
- Role of premedication
- Documentation
- Renal anatomy and physiology
most important method of reducing the risk of idiosyncratic CM reaction
Use LOCM
pretreatment with steroids will reduce the rate of idiosyncratic CM
Role of premedication
adverse reaction to CM administration must be appropriately documented
Documentation
Elements that must be captured:
- Amount and type of contrast injected
- Signs and symptoms of the reaction
- Interventions or medications given during the reaction and patients response to treatment
- Final outcome (discharged or admitted)
paired organs that lie behind the parietal peritoneum
Renal anatomy and physiology
level of T12-L3
Renal anatomy and physiology
0.5% of total body weight, receives ____ of total arterial blood
20-25%
contains _____ nephrons per kidney
1-2M
the ability of the kidney to remove a substance from the blood
Clearance
volume of plasma that is cleared of a specific substance in a given time
Clearance
GFR
Glomerular Filtration Rate
Glomerular Filtration Rate (GFR)
60-120 mL/min (normal),
16-59 mL/min (kidney disease),
0-15 mL/min (kidney failure)
ERPF
Effective Renal Plasma Flow
Effective Renal Plasma Flow (ERPF)
500 mL/min
used for the estimation of GFR
Inulin
ideal filtration marker
Inulin
metabolically inert (not digested or absorbed in the stomach)
Inulin
cleared only by kidney
Inulin
demanding and time-consuming
Inulin
index of GFR
Serum Creatinine
a by-product of muscle protein metabolism generated by the body at a fairly steady rate and excreted entirely in the urine
Creatinine
Female Creatinine level
0.5 - 1.1
Male Creatinine level
0.6 - 1.0
Creatinine clearance test can be done using samples from _________ & _______
blood, urine
Methods to measure creatinine or kidney function
Effective Renal Plasma Flow,
Glomerular Filtration Rate
produces urine by filtering out from the blood small molecule and ions and then reclaiming the needed amount of useful materials
Nephron
