Fig. 1
From: Iatrogenic hemodilution: a possible cause for avoidable blood transfusions?
Continuous hemoglobin (SpHb) and Pleth Variability Index (PVI) during hepatic (a) and spinal (b) surgery. a The gradual increase in the PVI to very excessive values (close to 40%) signifies the development of hypovolemia during the hepatic resection phase. Aggressive fluid rehydration at the end of the resection phase led to the immediate decrease of the PVI and a simultaneous significant decrease in SpHb denoting acute hemodilution, which in this case probably reveals true anemia. b The characteristic decrease in both SpHb and PVI following fluid administration denotes the development of iatrogenic hemodilution during spine surgery. SpHb and PVI traces obtained from the ROOT monitor, Masimo Inc., Irvine, CA, USA. Panel a reproduced with permission from Hospital Healthcare Europe (http://www.hospitalhealthcare.com/theatres/haemodilution-and-avoidable-blood-transfusions)