Complications of Contrasts & Angiography

Angiography

“It is an imaging technique used to visualize the lumen of blood vessels and organs of the body by means of injecting a radio opaque agent into the blood vessels followed by images taken using x-ray based techniques”

ANGIOGRAPHY PERFORMED IN…..

Heart--( coronary angiography)

Brain --(cerebral angiography)

Lungs --(pulmonary angiography)

Kidneys --(renal angiography)

Arms or legs --(extremity angiography)

INDICATIONS

Congenital arterial anomalies

Aneurysms

Stenosis

Thrombosis

Arteritis

Trauma

Embolus

AV fistulas

Hemorrhage

Masses/tumors

The Angiography Procedure

A catheter is inserted through a small cut and into one of the arteries, usually in the groin . A radiologist then guides the catheter into the area that needs to be examined. The contrast medium is injected through the catheter and into the blood vessel. A series of X-rays is then taken.

Anesthesia

COMPLICATIONS OF CONTRASTS

Contrast Media

Contrast media is primarily divided into two categories:

high osmolar contrast media (HOCM)

low osmolar contrast media (LOCM)

• Most non-ionic agents are placed into the LOCM category while all ionic agents are in the HOCM category.

Mechanisms of Contrast Reactions

ANAPHYLACSIS

Anaphylactic reactions are the immediate type of hypersensitivity that result from interaction of antigens with specific antibodies bound to mast cells and basophils.

They involve the release of vasoactivebronchoconstrictive substances such as: Histamine, Leukotrienes

Occur within 30 minutes 60% within 5 minutes

94% within 20 minutes

Respiratory decompensation: 40% of deaths

Anaphylactic Reaction

Mechanism

CHEMOTOXICITY

Chemotoxic effects are related to does and chemical nature of agent (osmolality, viscosity, hydrophilicity, etc.)

More likely in debilitated or unstable patients

MAJOR RISK FACTORS

Allergy(asthma)extremes of age

Cardiovascular disease

Previous history

MINOR RISK FACTORS

DIABETES MELLITUS

DEHYDRATION

IMPAIRED RENAL FUNCTION

HAEMOGLOBINOPATHIES

B BLOCKERS

INTERLEUKIN 2 THERAPY

MILD REACTIONS

Sneezing

Mild urticaria

Nausea

Mild pallor

Sweating

Mild urticaria

Arm pain

Tachycardia/bradycardia

INTERMEDIATE REACTIONS

Widespread urticaria Bronchospasm Laryngospasm Angioneurotic edema Moderate hypotension Faintness Headache Severe vomiting Rigors Dysnoea Chest/abdominal pain

SEVERE REACTIONS

Cardiopulmonary collapse

Severe hypotension

Pulmonary edema

Edema of glottis

Bronchospasm

Laryngospasm

MI

Arrhythmias

Loss of consciousness

NEPHROTOXICITY

Oliguric renal failure(severe form)

Direct toxic effect

Vasoconstriction

Cast formation in tubules leading to obstruction

IODISM

Interference of free iodine present in contrast with iodine function tests of thyroid----hyperthyroidism

Management of Contrast Reactions

Reassurance

Emergency drugs

I/V fluid administration

Oxygen administration

Vagal reaction(hypotension +bradycardia)>epinephrine

Anaphylactoid reaction(hypotension +tachycardia)>atropine

COMPLICATIONS OF ANGIOGRAPHY

INFECTION

Improper sterilization techniques

ARTERIAL WALL DAMAGE

Directly by needle/catheter puncture.

Subintimal injection

THROMBOSIS

Trauma to arterial wall

Subintimal injection of contrast

Prolonged cathterization:3000 units of heparin(systemic heparinization)

ALLERGY

Urticaria

Sneezing

Coughing

Severe form: cardiopulmonary collapse

Severe reaction:dexamethsone10-20mg iv

Edema of glottis: epinephrine 0.5 mg, Subcut/ im

Antihistamine

HYPOTENSION

Release of chemical mediaters

Patient having atheromatous stenosis---high risk

Hemiplegia---carotid thrombosis

CATHETER CLOT EMBOLUS

Serves as a focus for thrombosis

Stripped off as catheter is withdrawn

Clot formation at the catheter tip

CHOLESTEROL EMBOLIZATION

Atheromatous disease

Cholesterol crystalsdislodged into circulation

AIR EMBOLUS:

When syringe points upward or horizontally.

HAEMATOMAS AND FALSE ANEURYSMS:

Application of firm pressure at the puncture site

Hypertensive's are highly susceptible.

Anticoagulant drugs must be stopped

NERVE DAMAGE

NERVE PALSIES:

Femoral nerve palsy

Brachial plexus damage during transaxillarycatheterization.

Caused by direct puncture or by hematoma compression

VITAL ORGAN DAMAGE

Cortical blindness—vertebral angiography

Paraplegia: Artery of Adamkewicz, supplies the cord from T8 downwards.

Tetraplegia: excess contrast in deep cervical artery

Ventricular fibrillation, MI.

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