The influence of continuous veno-venous hemofiltration on cardiac output value monitored by transpulmonary thermodilution technique in critical patients

Abstract

To investigate the influence of continuous veno-venous hemofiltration (CVVH) on cardiac output (CO) value and parameters of hemodynamics monitored by transpulmonary thermodilution technique in critical patients. A prospective cohort study was conduced. Sixty-two critical patients admitted to intensive care unit (ICU) of Zunyi Medical College Affiliated Hospital from January 2011 to October 2015 were enrolled. All of the patients received CVVH through femoral vein puncture catheter. The CO value was monitored before CVVH operation, immediately after CVVH operation (8?centigrade normal saline was injected immediately after the output of blood from the arterial end), 5 minutes after operation, the time at the sudden interruption (press pause key after 10 minutes of operation) and resumed immediately, 15 minutes and 30 minutes after operation by pulse-indicated continuous cardiac output (PiCCO) with transpulmonary thermodilution method. The changes in heart rate (HR), mean arterial pressure (MAP), central venous pressure (CVP), and blood temperature were observed at all time points. From CVVH before start to 5 minutes thereafter, CO values were not significantly changed in patients, fluctuating in 6.96 (7.33, 8.67)-6.98 (6.43, 7.45) L/min. When CVVH was suddenly interrupted, CO value was immediately increased to the peak 8.04 (7.36, 8.77) L/min, which showed statistically significant difference as compared with other time points (all P < 0.01). Immediately after the CVVH recovery from interruption, the CO value dropped to 4.71 (4.14, 7.26) L/min, and it was significantly lower than those at other time points (all P < 0.01). With the CVVH recovery, the patients' CO value was gradually restored to the stable operation ahead of interruption [4.71 (4.14, 7.26)-6.85 (6.08, 7.26) L/min]. During CO monitoring, HR, MAP, CVP and blood temperature of the patients were at the same level, and no significant changes were founded. CVVH interruption of immediate PiCCO monitoring CO value were significantly increased, immediately after the CVVH recovery the CO value were significantly reduced, and the normal operation of CVVH did not affect the CO value monitoring. Hemodynamics and blood temperature of all patients were stable during CVVH.