Original Article

Oxygenation of a Crystalloid Cardioplegic Solution

Extracorporeal Circulation Technology Department, College of Health Related Professions and Division of Cardiothoracic Surgery, Medical University of South Carolina, Charleston, SC

^* Direct communications to: William E. Hodges, Jr., ECT Program, Medical University of South Carolina, 171 Ashley Ave., Charleston, SC 29412

Abstract

The purpose of this study is to compare the effectiveness of an alternative method of oxygenating a crystalloid cardioplegic solution to the use of a bubble oxygenator. Five hundred milliliters of 100% oxygen was introduced, using sterile technique, into 100 ml bags of Ringer's solution at varying temperatures (20°, 10°, and 4°C). The contents of the bags were shaken for one minute by hand and then cooled to 4°C or maintained at that temperature using a Shiley CSD 103 Cardioplegia Delivery Set. This method of oxygenation was compared to constant bubbling of 100% oxygen into Ringer's solution in a Shiley S70 bubble oxygenator at 4°C.

Samples of oxygenated solution from the bubble oxygenator were collected over a 60 minute time period. After 30 minutes the values stabilized and the last 12 samples were used as the reference for the bubble oxygenator. Samples of the solutions cooled using the Shiley CSD 103 were taken when the temperature stabilized at 4°C. All 4°C samples were then analyzed for pO₂ using an IL 326 blood gas analyzer and the values compared for the various techniques. The results of this study showed the following pO₂ values:

The conclusion drawn from this study is that the use of Ringer's solution oxygenated and maintained at 4°C is a cost effective alternative to the use of a bubble oxygenator to increase the pO₂ in crystalloid cardioplegic solutions.