Cardiorespiratory haemodynamics in haemorrhage and sepsis: a comparative study.

The standard wigger's method was used to induce haemorrhagic shock (HS) in anaesthetised dogs by bleeding to a mean arterial pressure (MAP) of 50mmHg for 2 hours and then to 30mmHg for 1 hour followed by reinfusion of the shed blood. Concurrent with this, endotoxin shock (ES) was also induced by intravenous infusion of Escherichia coli endotoxin in anaesthetised dogs. Cardiorespiratory function parameters in both experiments were recorded throughout the experiment on a multichannel poligraph monitor. The experimental protocol was designed to compare the effect of haemorrhage and sepsis on cardiopulmonary haemodynamics. Indices for cardiac performance, that is cardiac output (CO) and maximum dp/dt of left ventricular pressure (max dp/dt of LVP) were observed to deteriorate at a faster rate with sepsis than with haemorrhage while indices for pulmonary function, that is, pulmonary arterial pressure (PAP) and pulmonary vascular resistance (PVR) were shown to deteriorate much earlier and faster with sepsis than with haemorrhage. These experiments indicated that, cardiorespiratory disturbance is more severe with sepsis than with haemorrhage.