Ask the Clinical Instructor: A Q&A Column for Those New to the Cath Lab

We recently were performing a right heart catheterization on a patient. Our policy is that all patients get oxygen during their procedure. We had a debate about whether we should do this for the right heart cath portion. – Orlando, Florida Cath Lab Team Member I have seen where “prophylactic” administration of oxygen during catheterization procedures occurs. This varies from facility to facility across the country. The usage of oxygen in this manner is completely up to the facility, and there is really nothing evidenced-based that is for or against this practice. It can be part of planning and being prepared. However, oxygen should NEVER be withheld from a patient that needs it. When performing certain right heart catheterization procedures, the use of oxygen CAN cause erroneous data. For a simple right heart catheterization, when only pressures are being monitored, the use of oxygen is inconsequential. It’s when procedures involving oxygen saturations are being performed that oxygen administration can skew results. Obtaining saturations for the Fick Method of cardiac output calculation or analysis of shunts can be erroneous if supplemental oxygen is administered. For proper use of the Fick Method, the patient must be breathing room air during blood sample collection.¹ Supplemental oxygen therapy should be discontinued at least 10 to 15 minutes before determination of the cardiac output by the Fick Method. If oxygen cannot be discontinued safely, an alternative to the Fick Method should be used.² More importantly, to reduce chances of error, a steady state (where cardiac output and oxygen consumption are constant during drawing of samples) should be present.³ This means that the patient should be kept calm and relaxed during the procedure. Over-sedation that results in less than optimal respirations/ventilations would also affect the oximetry results. With that being said, the decision for administration of oxygen during the procedure comes from the clinical judgment of the physician, and again, never withhold oxygen from a patient that needs it. Email your question to Todd Ginapp at tginapp@rcisreview.com

References

1. Libby P, Bonow RO, Mann DL, Zipes DP. Braunwald’s Heart Disease: A Textbook of Cardiovascular Medicine. 8th Edition. Philadelphia: Elsevier Science; 2007. 2. Kern MJ. The Cardiac Catheterization Handbook. 4th ed. Philadelphia, Penn.: Mosby; 2003. 3. Baim DS, ed. Grossman’s Cardiac Catheterization, Angiography, and Intervention. 7th ed. New York, NY: Lippincott Williams & Wilkins; 2006.

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