Comparative Analysis of arterial Gases and Acid-base status in Patients with Congenital and Acquired Heart Disease at Preoperative Period, During Extracorporeal Circulation, and Postoperative Period

Lee, Dong Seok; Lee, Bong Keun; Kim, Song Myung

Abstract

BACKGROUND: Patients with cardiac diseases who have structural defects in their heart bring about metabolic insult such as preoperative acid-base imbalance. Cardiac operation requires many nonphysiologic procedures such as extracorporeal circulation, hypothermia, and hemodilution. We studied the acid-base status of surgical heart diseases pre-operatively, during extracorporeal circulation, and post-operatively and researched the treatment indications of acid-base disturbances. MATERIAL AND METHOD: From January 1997 to May 1999, fifty two cases of open heart surgery were carried out under extracorporeal circulation, which divided into a set of pediatric and adult groups, congenital and acquired groups, non-cyanotic and cyanotic groups, The alpha-stat arterial blood gas analysis was done in each group during the preoperative period, during the operation with extracorporeal circulation, and during the postoperative period. RESULT: Before surgery, all patients present metabolic acidosis, PaO2 was low in adult group and acquired group and compensatory respiratory alkalosis was noted in cyanotic group. During extracorporeal circulation, adult group revealed alkalosis and normal in acquired group. Pediatric group presents low PaCO2, metabolic acidosis and respiratory alkalosis. Congenital group and non-cyanotic group showed non-compensatory alkalosis trend and non-compensatory respiratory acidosis were observed in cyanotic group during extracorporeal circulation. Postoperative acid-base status of adult group was recovered to normal and the standard bicarbonate was increased in the acquired group. All of the pediatric, congenital non-cyanotic, and cyanotic groups revealed the lack of buffer base.
CONCLUSION
In Preoperative period, correction of metabolic acidosis was required in pediatric, congenital and non-cyanotic groups, while treatment of metabolic acidosis and low PaCO2 were required in adult and acquired groups. In the cyanotic group, metabolic acidosis and respiratory alkalosis needed to be corrected preoperatively. Using the extracorporeal circulation, minimal correction was required except acquired group which showed normal acid-base balance. In postoperative period, restriction of bicarbonate was required for acquired group while increase of buffer base was required for pediatric, congenital, non-cyanotic, and cyanotic groups.