RESUMEN
OBJECTIVE: To compare "central venous pressure" in pediatric patients in a clinical setting as measured from catheters in the infrahepatic inferior vena cava and the right atrium. DESIGN: Prospective, unblinded study. SETTING: Cardiothoracic intensive care unit of a tertiary care university hospital. PATIENTS: Thirty-three pediatric cardiac surgical patients, 2 days to 92 months of age (mean 24 +/- 4 months). INTERVENTIONS: All patients had intraoperative placement of an 8-cm, double-lumen, femoral venous catheter and a transthoracic right atrial catheter. Patients were studied for 0 to 2 days after surgery. MEASUREMENTS AND MAIN RESULTS: Measurements were obtained during mechanical and spontaneous ventilation. Although not statistically identical, measurements of "central" venous pressure in the inferior vena cava and right atrium correlated well (r2 = .87 for mechanical ventilation; r2 = .83 for spontaneous ventilation). Of 31 data pairs in mechanically ventilated patients, the absolute difference in pressures was as large as 3 mm Hg in three patients and <3 mm Hg in all the rest. In 15 spontaneously breathing patients, there were only three data measurements where the difference in pressure was 2 mm Hg and none of the differences was greater. In spontaneously breathing patients, the phasic changes due to respiratory variations in venous pressure were in phase in both the intrathoracic and intra-abdominal catheter positions. CONCLUSIONS: We conclude that while "central" venous pressures measured in the inferior vena cava and in the right atrium are not statistically identical, any differences are well within clinically important limits. Placement of central venous pressure catheters in the inferior vena cava by the femoral venous approach is a reliable alternative to cannulating the superior vena cava in pediatric patients without clinically important intra-abdominal pathology and with anatomic continuity of the inferior vena cava with the right atrium. Relatively short femoral vein catheters allow adequate measurement of central venous pressure without concern for exact catheter tip position and without the risk of right atrial perforation, intracardiac arrhythmias, and inadvertent puncture of carotid and intrathoracic structures. Unlike previously reported results in neonates, we found that the phasic changes of venous pressure with the respiratory cycle were similar in both intrathoracic and intra-abdominal recordings, making this an inappropriate clinical indicator of venous catheter tip position.
Asunto(s)
Función del Atrio Derecho , Procedimientos Quirúrgicos Cardíacos , Presión Venosa Central , Monitoreo Intraoperatorio , Vena Cava Inferior/fisiología , Cateterismo Cardíaco , Cateterismo Venoso Central/métodos , Niño , Preescolar , Humanos , Lactante , Recién Nacido , Presión , Estudios Prospectivos , Respiración Artificial , Presión VentricularRESUMEN
Recent laboratory investigations have shown significantly improved donor heart preservation and function when the University of Wisconsin solution (UW) is used for arrest and storage. These findings prompted us to compare UW to Stanford solution in a clinical trial. After giving informed consent, patients were blindly randomized to receive a heart arrested and stored in UW or a heart arrested in Stanford solution and stored in normal saline. Orthotopic transplants were performed in a routine manner. Fourteen patients with a mean age of 54 years were randomized to UW, and 15 patients with a mean age of 51 years were randomized to Stanford solution. Mean donor ages (UW 27 years, Stanford 24 years) and ischemic times (UW 150 minutes, Stanford 135 minutes) were similar. Several differences were observed intraoperatively. At end ischemia, mean adenosine triphosphate (UW 5.87 mmol/gm wet weight, Stanford 4.75 mmol/gm) and creatine phosphate (UW 9.26 mmol/gm, Stanford 4.75 mmol/gm) levels were higher in the UW hearts (p less than 0.05). Defibrillation requirements (UW 14% [2/14], Stanford 53% [8/15]) were significantly less in the UW group (p = 0.05). The number of patients requiring temporary intraoperative pacing also showed a significant difference with 7% (1/14) of UW patients versus 47% (7/15) of Stanford patients requiring pacing (p less than 0.05). Intraoperative requirement for inotropic support showed a trend in favor of the UW group. End-ischemic and postreperfusion histologic characteristics were similar between the two groups. No differences in hemodynamics or ejection fractions were noted postoperatively, but trends toward improved rhythm and decreased inotropic support were present in the UW group. Overall 6-month survival rates were similar (UW 86% [12/14], Stanford 93% [14/15]). No preservation-related deaths occurred. We conclude: (1) UW is a safe and effective preservation solution for human cardiac transplantation; (2) considering the improved end-ischemic adenosine triphosphate and creatine phosphate levels, decreased defibrillations, decreased intraoperative pacing, and trend toward decreased requirement for inotropic support in the UW group, UW appears to be superior to Stanford solution for donor heart preservation.