Clinical assessment of cardiac performance in infants and children following cardiac surgery

Abstract

Objective: To compare clinical assessment of cardiac performance with an invasive method of haemodynamic monitoring.

Design and setting: Prospective observational study in a 16-bed tertiary paediatric intensive care unit.

Patients and participants: Infants and children undergoing cardiopulmonary bypass and surgical repair of congenital heart lesions.

Interventions: Based on physical examination and routinely available haemodynamic monitoring in the paediatric intensive care unit, medical and nursing staff assessed cardiac index, systemic vascular resistance index and volume status. Clinical assessment was compared with cardiac index, systemic vascular resistance index and global end diastolic volume index, obtained by femoral artery thermodilution.

Measurements and results: A total of 76 clinical estimations of the three parameters were made in 16 infants and children undergoing biventricular repair of congenital heart lesions. Agreement was poor between clinical and invasive methods of determining all three studied parameters of cardiac performance. Cardiac index was significantly underestimated clinically; mean difference was 0.71 l min(-1) m(-2) (95% range of agreement +/-2.7). Clinical estimates of systemic vascular resistance (weighted kappa=0.15) and volume status (weighted kappa=0.04) showed poor levels of agreement with measured values and were overestimated clinically. There was one complication related to a femoral arterial catheter and one device failure.

Conclusions: Routine clinical assessment of parameters of cardiac performance agreed poorly with invasive determinations of these indices. Management decisions based on inaccurate clinical assessments may be detrimental to patients. Invasive haemodynamic monitoring using femoral artery thermodilution warrants cautious further evaluation as there is little agreement with clinical assessment which is presently standard accepted care in this patient population.