Proposal of Manifold Variation for Use During Cardiac Catheterization

Roughly 5 million diagnostic cardiac catheterization procedures are performed in North America and Europe, with associated major complications at around 0.1%.¹ The introduction of air bubbles into the coronary circulation is a rare complication of cardiac catheterization, ranging in incidence from 0.1 to 0.3%, and is almost always iatrogenic.^2,3 Air bubbles within the arterial system behave in a similar way to solid emboli and can cause occlusion of end arteries, leading to tissue infarction and increased patient morbidity and mortality.^2,3 There are several potential causes of an air embolization during coronary angiography. It most frequently occurs as a result of improper flushing or aspiration of catheters used for vascular procedures and the removal of the injection syringe attached to manifold for intracoronary medication administration.

Intracoronary nitroglycerin is commonly administered during a diagnostic cardiac catheterization. Reasons for its use include better visualization of the vessel, and elimination of potential presence of a coronary spasm. In order to decrease the rate of systemic or coronary air embolization during intracoronary medication delivery, our cardiac catheterization laboratory has modified a 3-line manifold (Figure 1) by inserting a stopcock pigtail attached to a 5 mL drug (nitroglycerin 100mcl in 1ml) syringe (Figure 2) on to the heparin flush line (Figure 3).

This modified construct (Figure 4) allows the operator to inject medication through the heparin flush line into the arterial circulation without manifold injection syringe exchange.

Proper management of the construct includes insuring all connections are tightened, and the system is prepped appropriately and airless before the start of the procedure. When needed, the stopcock is turned off to the flush bag; and the medication dosage is pushed into the manifold syringe. The stopcock is then turned off to the drug syringe and flush solution is aspirated into the manifold syringe. The manifold is always held in the upright position and visually inspected before any injection. Aspiration of blood back before injection of the drug into the coronary circulation ensures no air is present in the line. All medications and syringes on the field are labeled as appropriate.    

The benefit of this design is to keep the entire system closed during angiography in order to reduce the risk of air embolization associated with the manifold injection syringe exchange for intracoronary medication administration. Over the last three years, we have performed around 1500 diagnostic cardiac catheterizations using this construct and have found it safe, very easy and convenient to use. 

Bernetta Howard, BSN, CCRN, RN-BC, can be contacted at: bernetta.howard@va.gov.

References

1. Tavakol M, Ashraf S, Brener SJ. Risks and complications of coronary angiography: a comprehensive review. Glob J Health Sci. 2012 Jan 1;4(1):
2. 65-93. doi: 10.5539/gjhs.v4n1p65.
3. Khan M, Schmidt DM, Baiwa T, Shaley Y. Coronary air embolism: incidence severity and suggested approach to treatment. Cathet Cardiovasc Diagn. 1995; 36(4): 313-318.
4. Dib J, Boyle AJ, Chan M, Resar JR. Coronary air embolism: a case report and review of the literature. Catheter Cardiovasc Interv. 2006 Dec; 68(6): 897-900.