Reliability of Pulse Contour Cardiac Output Analysis in a Piglet Model of Multi-step Intra-abdominal Hypertension.

Abstract Background Pulse contour cardiac output (PCCO) analysis is a minimally invasive technique for continuous cardiac output (CO) measurement monitoring. PCCO requires calibration by transpulmonary thermodilution (TPTD). Studies showed good agreement between PCCO, TPTD CO and CO measured by pulmonary artery thermodilution (PATD) during stable hemodynamics. However, data are limited in patients with intra-abdominal hypertension (IAH). The objective is to compare the agreement between PCCO, TPTD CO, and PATD CO in a piglet model of multi-step IAH. Materials and methods Ten female domestic piglets were enrolled in this study. IAH was induced by stepwise carbon dioxide inflation into peritoneal cavity in anesthetized piglets. Following baseline registrations, intra-abdominal pressure (IAP) was increased and maintained at each IAP plateau of 10, 20, 30, and 40 mmHg for 15 min before CO measurements. CO was measured by PATD and simultaneously by 2 femoral artery PCCO catheters. One PCCO catheter was recalibrated by TPTD at each IAP plateau while the other was only calibrated at baseline. Results In pooled data of different IAP stages, TPTD CO and recalibrated PCCO (R-PCCO) showed excellent correlation (r2 = 0.94 and 0.93) and small bias (−0.09 and −0.09 L/min), respectively, compared with PATD CO. However, PCCO without recalibration (NR-PCCO) were not accurate during IAH (r2 = 0.58, bias: +0.32 L/min). When IAP increased to 30 mmHg, NR-PCCO failed to agree with PATD CO (r2 = 0.47, bias: +0.52 L/min). On the contrary, a clinically accepted agreement between TPTD CO, R-PCCO, and PATD CO was observed at different IAP stages. Conclusions TPTD CO and R-PCCO agreed with PATD CO in this piglet model of multi-step IAH. On the contrary, NR-PCCO failed to agree with PATD CO when IAP increased to 30 mmHg or more. PCCO analysis needs recalibration in this condition.