College Answer

• Physical examination [warm hands, urine output, mentation]
• Vital signs – heart rate, blood pressure, oxygenation Lactate
• Urine output

• Blood pressure response to passive leg raise or fluid challenge

• Invasive arterial monitoring [Vigileo/LiDCO (cardiac output, stroke volume variation, stroke volume)]

• Central venous pressure measurement, central venous oxygen saturation

• Invasive cardiac monitoring
  • PiCCO measurements [Intra thoracic blood volume, global end diastolic volume, cardiac output, stroke volume variation]
  • Pulmonary Artery Flotation Catheter [pulmonary artery occlusion pressure, cardiac output, mixed venous oxygenation]
• Echocardiogram [cardiac output, left ventricular ejection fraction, IVC collapsibility]

• Transcutaneous Doppler [cardiac output/stroke volume variation]

• Research tools
  • Techniques for measuring microvascular perfusion eg contrast US, SDF Techniques for measuring tissue oxygenation eg, gastric tonometry [D pCO2], sublingual tonometry, microdialysis
  • Impedance cardiography [cardiac output, stroke volume variation, stroke volume]

Discussion

This question is a "list" question, and thus one should resist the temptation to critically evaluate, or to compare and contrast. A list of techniques is reasonably easy to generate. Specifically, techniques to assess volume-responsiveness are extensively discussed in the section concerned with Fluid Resuscitation, Vasopressors and Inotropes. If one needed to generate a dumb noncomparative list for whatever reason, one should do so in a manner which follows a system of some sort.