Is compartment pressure related to plasma colloid osmotic pressure, in patients during and after cardiac surgery?

Abstract

Haemodilution is always considerable during cardiopulmonary bypass (CPB). If this extra fluid sits in the muscle compartments then a corresponding rise in the compartment pressure (CP) is to be expected. The aim of this study was to measure pressure changes in a body compartment with new equipment, the MTC (Microtransducer). Changes in plasma colloid osmotic pressure (COP) were also measured during and after CPB to find a connection, if any, between CP and plasma COP. Ten elective consecutive CPB patients were studied. A 3-French (3-F) catheter-size electronic MTC was inserted in an anterior tibial compartment before CPB. The CP was monitored for 48 h. Plasma COP was also measured before, during and after CPB. CP increased significantly during and after CPB in all patients (p=0.01). COP decreased significantly in all patients (p=0.005), but no correlation was found between changes in COP and CP values in this study. Most of the patients reached their highest CP just after weaning off bypass. The CP remained elevated for 48 h, even though it then tended to decrease again. None of the patients reached the starting value within 48 h. COP decreased rapidly after going on bypass, but returned towards its starting value approximately 6 h after bypass. It is concluded that CP increases considerably during and after CPB and stays increased for at least 2 days after CPB. COP decreases during CPB, but reaches normal values 6 h after the CPB. No correlation was found between changes in CP and COP The MTC is a safe and easy way to measure intracompartment pressure.

High colloid oncotic pressure priming of cardiopulmonary bypass in neonates and infants: implications on haemofiltration, weight gain and renal function

“…There were several trials on the influence of colloid oncotic pressure (COP) on CPB and renal function showing conflicting results [9][10][11][12][13]. Therefore, using human albumin to increase oncotic pressure is not practised regularly [1].…”

Changes in muscle compartment pressure after cardiopulmonary bypass

“…In a previous study, we found that the pressure in a closed muscle compartment rises significantly during and after cardiopulmonary bypass (CPB) and remains increased up to 48 h. 1 We assumed that the inflammatory response and edema causes the pressure changes in the compartment.…”