Patient monitoring

A method of monitoring a subject during a period or periods of hemodynamic instability, the method comprising:

• (a) continuously analysing and processing at least one of a blood pressure, arterial volume, or a plethysmographic signal obtained from the subject using a processor comprising software arranged to derive a plurality of complementary parameters throughout the monitoring of the subject;
• and
• (b) displaying images on a display based on an interaction between the display and the processor, the images representing a derived plurality of complementary parameters, wherein the images comprise:
• at least one image representing graphically at least one stress related hemodynamic parameter plotted against time to provide an early or immediate indication of a change in the hemodynamic status, thereby indicating a requirement for an intervention, wherein the at least one stress related hemodynamic parameter is selected from mean arterial pressure, systolic pressure, diastolic pressure, heart rate, stroke volume, cardiac output, systemic vascular resistance and any of these parameters indexed to take account of the body surface area of the subject;
• and
• at least one image representing graphically at least one fluid responsiveness parameter plotted against time to provide an indication of the hydration level and associated ventricular pre-load status of the subject to determine whether an intervention is required, wherein the intervention comprises modulating hydration level or modulating other therapeutic administered to influence the hydration or hemodynamic status of the subject, wherein the at least one fluid responsiveness parameter is selected from stroke volume variation (SVV), pulse pressure variation (PPV), systolic pressure variation (SPV), and pulse oximetry plethysmographic waveform amplitude;
• wherein the method comprises deriving the percentage variation around a rolling mean value for stroke volume (SV) or pulse pressure (PP) on a continuous beat-to-beat basis,
• wherein the at least one image representing graphically at least one stress related hemodynamic parameter is displayed in the form of at least one image representing current changes in the stress related hemodynamic parameter plotted against time in combination with at least one image representing longer term changes in the stress related hemodynamic parameter plotted against time, wherein the at least one image displaying current changes in the stress related hemodynamic parameter comprises an expanded view of a portion of the image representing longer term changes in the stress related hemodynamic parameter thus facilitating monitoring of current changes in the stress related hemodynamic parameter whilst simultaneously allowing monitoring of longer term changes in the stress related hemodynamic parameter, the at least one image displaying current changes in the stress related hemodynamic parameter and the at least one image representing longer term changes being simultaneously displayed in a spatially separate manner to ensure they can be viewed simultaneously without requiring input of a user,
• the method further comprises displaying at least one image representing the percentage variation around the rolling mean value for stroke volume (SV) or pulse pressure (PP) plotted against time on a continuous beat-to-beat basis to indicate current changes in the at least one fluid responsiveness parameter, and
• wherein the at least one image representing graphically the at least one fluid responsiveness parameter is displayed in the form of at least one image representing longer term changes in the fluid responsiveness parameter plotted against time, thus facilitating monitoring of current changes in the at least one fluid responsiveness parameter whilst simultaneously allowing monitoring of longer term changes in the at least one fluid responsiveness parameter, the at least one image representing the percentage variation and the at least one image representing longer term changes in the fluid responsiveness parameter being simultaneously displayed in a spatially separate manner to ensure they can be viewed simultaneously without requiring input of a user.