PiCCO
PiCCO, an acronym for pulse contour continuous cardiac output, is a monitor used to monitor cardiac output and other haemodynamic parametres in patients with shock in the intensive care unit. It requres a central venous catheter and a special arterial cannula (PiCCO catheter) which is inserted into the femoral artery. Using a technique called transpulmonary thermodilution and pulse contour analysis, the monitor can estimate many different haemodynamic parametres which can help guide management, especially when there is a complex haemodynamic failure, such as when there is a combination of multiple different types of shock. It can help tell whether fluids, inotropes, vasoconstrictors, or vasodilators is more helpful to the patients.
An alternative to PiCCO is pulmonary catheters like Swan-Ganz.
Haemodynamic parametres measured
- Indicators of cardiovascular status
- Cardiac output (CO)
- Indicators of filling pressures
- Indicators of cardiac preload
- Global End-Diastolic volume (GEDV)
- Intrathoracic blood volume index (ITBVI)
- Indicators of fluid responsiveness
- Stroke volume variation (SVV)
- Pulse pressure variation (PPV)
- Indicators of afterload
- Indicators of cardiac contractility
- Global ejection fraction (GEF)
- Pressure velocity increase (dPmx)
- Cardiac function index (CFI)
- Indicators of pulmonary oedema
- Extravascular lung water index (EVLWI) – “how much water is in the lungs?”
- Pulmonary vascular permeability (PVP) – “why is there pulmonary oedema?”
For example, if the systemic vascular resistance is low, a vasoconstrictor like noradrenaline may improve the peripheral perfusion of the patient. If it is high, that means that the afterload of the heart is high, which can reduce the cardiac output. A vasodilator like nitroprusside or glyceryl trinitrate may improve the cardiac output.
An elevated SVV and PPV indicate that the patient may respond positively to fluid therapy.