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Correspondence  |   September 2012
We Are the Ones Who Impede Our Own Progress
Author Notes
  • Memorial Sloan–Kettering Cancer Center, Weill Cornell Medical College, New York, New York.
Article Information
Correspondence
Correspondence   |   September 2012
We Are the Ones Who Impede Our Own Progress
Anesthesiology 9 2012, Vol.117, 682. doi:10.1097/ALN.0b013e3182625828
Anesthesiology 9 2012, Vol.117, 682. doi:10.1097/ALN.0b013e3182625828
To the Editor: 
Recently, an updated Practice Advisory has been published regarding perioperative visual loss associated with spine surgery.1 I feel the need to highlight certain statements in the Advisory that are contradictory to the long-standing effort in the anesthesiology/critical care communities to place fluid management on a more rational basis. Starting decades ago, significant effort has been made to highlight the fact that central venous pressure (CVP) is unrepresentative of volume status.2,3 The fact that this is a difficult and ongoing issue is exemplified by the recent review of CVP physiology by Gelman, in which much the same principles are reinforced.4 It should be pointed out that many recent publications focus on goal-directed fluid management, yet not one of these studies uses the CVP as the parameter to be optimized.5 Despite this, the Practice Advisory makes the following statements:
“Management of Intraoperative Fluids: The literature is insufficient to assess the relationship between the monitoring of intravascular volume….,”“The consultants, SNACC, NANOS, and NASS members agree that intravascular volume should be monitored continually in high-risk patients.”
Both these statements are well written and the practitioner can be reassured in implementation of these recommendations. However, these statements are followed by one that does significant disservice to our profession: “Advisory for Management of Intraoperative Fluids: Central venous pressure monitoring should be considered…..” This statement sets us back to the 1970s by closely linking fluid management to CVP, and it does so in the setting of prone position during mechanical ventilation! It may be that CVP can be monitored (i.e.  , there is no reason not to record CVP pressures if a catheter is in place, to what purpose is unclear). However, a disservice is done by linking CVP in any fashion with the management of intraoperative fluids, as this Advisory does. In the Consultant surveys, questions regarding intravascular fluid management and CVP monitoring are asked separately, although unfortunately combined under the same heading of intraoperative fluids. The barely positive agree response for use of CVP monitoring of high risk patients (39%vs.  56% of equivocal or disagree responses) is then translated into a recommendation where CVP monitoring is linked to fluid management. This insidious ‘creep’ of interpretation demonstrates how deeply instilled the concept of CVP and intravascular volume status is in our collective psyches. High-profile publications such as this Advisory should do more to dispel these myths, rather than not so subtly perpetuating misconceptions that we are so diligently struggling to overcome.
References
Practice advisory for perioperative visual loss associated with spine surgery: An updated report by the American Society of Anesthesiologists Task Force on Perioperative Visual Loss. ANESTHESIOLOGY 2012; 116:274–85
Shoemaker WC, Society of Critical Care Medicine: Physiologic monitoring of the critically ill patient: Central venous pressure. Textbook of Critical Care, 2nd edition. Philadelphia, Saunders, 1989, p 150
Shippy CR, Appel PL, Shoemaker WC: Reliability of clinical monitoring to assess blood volume in critically ill patients. Crit Care Med 1984; 12:107–12
Gelman S: Venous function and central venous pressure: A physiologic story. ANESTHESIOLOGY 2008; 108:735–48
Rinehart J, Liu N, Alexander B, Cannesson M: Review article: Closed-loop systems in anesthesia: Is there a potential for closed-loop fluid management and hemodynamic optimization? Anesth Analg 2012; 114:130–43