# (pneumatic sleeve or graduated compression stockings or mechanical thromboprophylaxis or sequential compression device).mp. or Intermittent Pneumatic Compression Devices/ (n=1479)
+
# (Passive leg raise or Pulse pressure variation or PPV or volume status or fluid challenge or fluid bolus or fluid responsive*).mp. or Hemodynamics/ or Cardiac Output/ or Fluid Therapy/ or Hypotension/ or Stroke Volume/ or Hypovolemia/ or Dehydration/ or Blood Pressure/ (n=587742)
+
# 1 and 2 (n=80)
+
# from 3 keep 2-3,5-6,8,10,12,16-17,21,23-24,30,32-33,35,37,42,44,48-50,52,56,58,62,69,73-75 (n=30)