Trigger points and concerns

Trigger Points and Concerns

The decision tree was developed to be used in conjunction with flow measurements using the oesophageal Doppler monitor.

A good understanding of cardiovascular physiology is essential, including preload, afterload and contractility. Always ensure optimal focus of the Doppler probe is achieved before analysing the data.

NOTE – These trigger points and concerns:​

  • Should not be assessed in isolation
  • Are not the same as physiological targets
  • Are indicative and not absolute
  • Are not prioritised

Primary Clinical Indicators

  • Hypotension: e.g. Systolic < 100 mmHg, MAP < 60-70 mmHg, or a clinically significant drop in MAP e.g. 30-40 mmHg from assumed ‘normal’ or baseline
  • Tachycardia: e.g. > 90 bpm
  • Oliguria: < 0.5 mL/kg/hr
  • Low Cardiac Output State

Flow Indicators

  • Reduced FTc: < 330 ms, or considered low for clinical condition e.g. any high resistant state
  • Low Cardiac Output: significantly below ‘normal’ e.g. CO < 4-6 L, CI < 2.5 L/min/m​²
  • Low Stroke Volume: significantly below ‘normal’ e.g. SV < 50-70 mL, SVI < 30 mL

Supplementary Clinical Indicators

Exclusions