Carbon dioxide-angiography for patients with peripheral arterial disease at risk of contrast-induced nephropathy

Table 1 Risk factors for the development of contrast-induced nephropathy

Risk factors for contrast-induced nephropathy
Increased age
Intravascular volume depletion
High volume or high osmolarity of contrast medium
Pre-existing chronic kidney disease (CKD)
Diabetes with CKD
The use of medications, including: calcineurin inhibitors, aminoglycosides, non-steroidal anti-inflammatory drugs, diuretics, angiotensin-converting enzyme inhibitors

Table 2 Overcoming complications associated with the use of carbon dioxide angiography

CO2 associated complication	Preventive and / or therapeutic strategy
Gas embolism	Blood carries dissolved CO2 to the lungs, where the gas is expired in a single pass, eliminating the possibility of gas embolism[79]
Explosive gas delivery	Inject 3-5 mL of CO2 into the catheter to remove any fluid or blood, decreasing gas compression and explosive delivery[75]
	Administer intra-arterial lidocaine before CO2 injection to resolve patient’s pain and prevent involuntary movement[80]

Table 3 Contraindications for the use of carbon dioxide angiography

Contraindication	What the clinician should do
CO2 arteriography performed above the diaphragm may result in cerebral air embolism if the patient has a left-to-right cardiopulmonary shunt	Do not use CO2 arteriography in patients with cardiac septal defect, pulmonary arteriovenous malformation (AVM), or known left-to-right cardiopulmonary shunt. In cases of critical requirement for CO2 angiography, place the patient in the Trendelenburg position during imaging
CO2 can mix with nitrogen to reduce the solubility of CO2	Avoid the use of nitrous oxide sedation and anesthesia
CO2 should be avoided for use in the venous circulation of patients that have a right-to-left intracardiac shunt	Do not use CO2 venography in patients with a right-to-left intracardiac shunt, including tetralogy of Fallot. In cases of critical requirement for CO2 venography, place the patient in the left lateral decubitus position to allow CO2 to trap and dissolve in the right atrium
Delayed absorption of CO2 may occur in patients with chronic lung disease, such as chronic obstructive pulmonary disease (COPD), who have a high baseline CO2 level	Monitor and adjust the time interval between CO2 injections in patients with a high baseline CO2 level
CO2 increases pulmonary artery pressure and can exacerbate pulmonary hypertension	Check the pulmonary arteries for accumulation of CO2 gas dissipation within the initial 30-45 s following CO2 injection

CO₂: Carbon dioxide.