Pediatr Cardiol 13:30-32, 1992 Pediatric Cardiology 9 Springer-Verlag New York Inc. 1992 Hemodynamic Effects of Peritoneal Dialysis in Three Children Following Open Heart Surgery C. Anthony Ryan, Orlando Hung, and Christian M. Soder Departments of Pediatrics and Anesthesia, Intensive Care Unit, IWK Hospital for Children and Dalhousie University, Halifax, Nova Scotia SUMMARY. We studied the hemodynamic responses of peritoneal dialysis (PD) in three children following open heart surgery. Hemodynamic measurements were made prior to a dialysis run, following the instillation of dialysis solution (20 ml/kg), and immediately prior to and 5 min after drainage of the peritoneal cavity. The same protocol was repeated 48 h later. There was a significant increase in right atrial pressure (RAP) and mean pulmonary artery pressure upon instillation of the dialysate into the peritoneal cavity (p < 0.01). However, cardiac index, mean arterial blood pressure (MAP), systemic (SVRI) and pulmonary vascular resistances (PVRI), left atrial pressure (LAP), and oxygen saturation did not change signifi- cantly. There were no significant differences between responses in the initial study and that performed 48 h later. PD is associated with modest right-sided hemodynamic changes which, in this small group of patients, did not compromise patient care. KEY WORDS: Peritoneal dialysis--Acute renal failure Acute renal failure (ARF) occurs in 2 [4] to 8% [1, 3, 5] of children undergoing open heart surgery. Poor preoperative renal function combined with dis- turbed renal blood flow during cardiopulmonary by- pass and cardiogenic shock are important factors in the pathogenesis of this serious complication [4]. The mortality rate among those who developed ARF following heart surgery is double the overall mortality rate varying from 65-89% [1, 4, 5]. Some authors have reported improved survival and recovery of renal function by using very early peritoneal dialysis (PD) [2, 8], although this is con- troversial [5]. Nevertheless, PD remains a useful method of controlling fluid and electrolyte im- balances in children with ARF secondary to a low cardiac output state. We recently had the opportu- nity to examine the hemodynamic effects of PD in three children following open heart surgery. Materials and Methods Three patients undergoing PD following open heart surgery for complex lesions were studied. Two children were catheterized Address offprint requests to: Dr. C. Anthony Ryan, Department of Pediatrics, 2C.300 WMHCS, 8440-112 Street, Edmonton, Al- berta T6G 2B7, Canada. transvenously with thermistor-tipped, four-lumen catheters (5F, SPS105H, Gould CritiCath, Oxnard, CA, USA), whereas one infant had a thermodilution probe (94-030-2.5F, EDSLAB, Ir- vine, CA, USA) inserted by the transthoracic route into the pul- monary artery (PA) during surgery. The decision to pass PA catheters was not related in any way to the present study. Cor- rect positioning of the PA catheter was judged by the typical changes of the pressure tracing when the balloon was inflated and the catheter was in the wedged position. Thermistor and catheter positions were confirmed by standard portable chest x- rays. The catheter was connected to a calibrated pressure trans- ducer which was leveled to the mid-axillary line and referenced to atmospheric pressure. Residual intracardiac shunting was ex- cluded by echocardiography. Cardiac output was determined in triplicate by the thermo- dilution technique using the Gould hemodynamic profile com- puter (No. sp1445, Gould Inc., Cardiovascular Production Divi- sion, Oxnard, CA, USA). Three to 5 ml of 5% dextrose/water solution, at room temperature, was injected by hand at end- expiration, and the average of the three readings (within 10% of each other) was recorded. Mean arterial pressure (MAP) was measured by an indwelling radial artery catheter. Left atrial pres- sure (LAP), right atrial pressure (RAP), mean pulmonary artery pressure (MPAP), heart rate, and electrocardiogram (ECG) were also measured and continuously displayed on a bedside cardiac monitor (OM model, Honeywell Inc., Pleasantville, NY, USA). All measurements were read at end-exhalation. From these hemodynamic measurements a cardiopulmo- nary profile (CPP) was formed which included these variables and other hemodynamic parameters, derived using standard for-