Perioperative Fluid Management in ERPs Robert H. Thiele, M.D. Assistant Professor University of Virginia First Do No Harm Intravenous fluids should be considered a pharmacotherapeutic agent Just like all pharmacotherapeutic agents, they can be both beneficial, and harmful Brandstrup et al. Ann Surg 238: 641, 2003 1
First Do No Harm Hypoperfusion Edema Bellamy MC. BJA 97: 755, 2006 What Doesn t Work? Mean Arterial Pressure There is NO meaningful correlation between MAP and DO 2 Why would you expect an arbitrary MAP to impact clinical outcomes in the perioperative environment? 2
What Doesn t Work? Asfar P. NEJM 370: 1583, 2014 What Doesn t Work? Central Venous Pressure Marik P. Chest 134: 172, 2008 3
What Doesn t Work? Urine Output Alpert RA et al. Surgery 95: 707, 1984 Why Is This So Hard? Chappell D et al. Anesthesiology 109: 723, 2008 4
Why Is This So Hard? Research suffers from a lack of standardization Investigators have normally named their traditional regimen the standard group and compared it with their own restrictive ideas A restrictive regimen in one study is often designated as liberal in another setup This shortcoming prevents even promising results from impacting daily clinical routine and makes any pooling of the data impossible Chappell D et al. Anesthesiology 109: 723, 2008 Why Is This So Hard? Hypoperfusion Edema Brandstrup ( Liberal [6.2L]) Brandstrup ( Restricted [3.8L]) Gan (Control [4.6L]) Gan (GDT [5.3L]) GanTJ. Anesthesiology 97: 820, 2002; Brandstrup et al. Ann Surg 238: 641, 2003 5
Why Is This So Hard? How much fluid administered may be less important than when it is given New focus: will intravenous fluid improve DO 2? Intraoperative Fluid Management Paradigm shift Will intravenous fluid improve cardiac output? How do we know this? 1) Measure fluid responsiveness 2) Measure cardiac output continuously Thiele RH et al. Canadian Journal of Anesthesia 62: 169, 2015 6
Timing is Important! Studies utilizing fluid responsiveness demonstrate no consistent impact on total fluid administration Buettner (systolic pressure variation): No difference in fluid administration or outcome Benes (stroke volume variation): More fluid in the goal-directed therapy (GDT) group Fewer complications and lower lactate in the GDT group Forget (PVI): 500 ml less fluid in the GDT group Lower lactate at all time points Buettner M et al. BJA 101: 194, 2008; Benes J et al. Crit Care 14: R118, 2010; Forget P et al. Anesth Analg 111: 910, 2010 Fluid Optimization (SV) Premise Maintaining patients at the peak of the Frank-Starling curve will maximize delivery of oxygen without requiring initiation of vasoactive pharmacologic agents Process: Give a small amount of fluid Measure the change in stroke volume When stroke volume no longer responds, the intravascular volume is optimized Disadvantages Requires accurate measure of stroke volume (e.g. esophageal Doppler monitoring [EDM]) 7
4/28/17 Fluid Optimization (Resp. Var.) Premise Optimizing recruitable stroke volume based on respiratory variation Arterial lines common (16% of patients) Masimo PVI relatively inexpensive and non-invasive (can be used on almost any patient) Disadvantages Does not actually measure change in SV Meaning confounded in patients with elevated PVR or RV failure Only useful in mechanically ventilated patients Does not have the evidence base enjoyed by EDM (yet) Esophageal Doppler continuously monitors cardiac output and the response to volume administration Pleth Variability Index monitors fluid responsiveness continuously based on the pulse oximeter waveform Thiele RH et al. Canadian Journal of Anesthesia 62: 169, 2015 8
Thiele RH et al. Perioperative Medicine 5:24, 2016 EDM and Hospital Stay (RCTs) RANDOMIZED CONTROLLED TRIALS Nine RCTs including 945 Subjects, weighted average 3.2 day reduction in LOS Year Author Patients n Outcome 1997 Sinclair Orthopedic surgery 40 Reduced mean stay 9 days 2002 Gan Major elective surgery 100 Reduced mean stay 2 days 2002 Venn Orthopedic 90 Reduced mean stay 6 days 2005 Wakening Colorectal 128 Decreased hospital stay 1.5 days 2006 Noblett Colorectal 108 Reduced mean stay 2 days 2007 Chytra Trauma 162 Reduced mean stay 5 days 2011 Pillai Radical Cystectomy 66 Reduced mean stay 4 days* (*NS) 2013 Jones Liver Resection 91 Reduced mean stay 3 days 2013 Li Liver Resection 160 Reduced mean stay 1.1 days 9
4/28/17 Schematic of Enhanced Recovery After Surgery (Source: NHS Enhanced Recovery Partnership) Do You Need Want A Device? 150 patients undergoing elective colorectal surgery were randomized to receive fluid therapy after either the goal of near- maximal SV guided by ED or the goal of zero balance and normal BW 10
Do You Need Want A Device? Not known whether GDFT is of value within an ER protocol incorporating fluid restriction elective colectomy 85 patients were randomized Srinivasa BJS 100:66, 2013 Do You Need Want A Device? Is GDT superior to a restrictive or zero balance approach? GDT (EDM) v. zero balance (B, S) or restrictive (P) Randomized trials of colorectal surgical patients Results (335 patients in 3 studies) No differences in complications No difference in length of stay Brandstrup BJA 109: 191, 2012; Srinivasa BJS 100:66, 2013; Phan TD Anaesth Int Care 42: 752, 2014 11
Do You Need Want A Device? Which group would you choose to be in? Pearse RM et al. JAMA 311: 2181, 2014 Do You Need Want A Device? Pearse RM et al. JAMA 311: 2181, 2014 12
Do You Need Want A Device? Many individuals have demonstrated reduced LOS without advanced monitoring However, the data on GDT (prospective RCTs) is more compelling than the ERAS data Advanced monitoring allows you to comfortably adopt a fluid restrictive strategy with a margin of safety You are more likely to detect the rare patient who is profoundly fluid responsive This will not be detected in a 100 patient case-control study Conclusions Intravenous fluid can cause harm Traditional ( static ) fluid management strategies are based on flawed logic and not supported by meaningful outcomes data Advanced hemodynamic monitoring ( dynamic indicators of volume) have been shown to improve outcomes in GDT studies Whether or not this holds true in the context of ERAS studies is somewhat controversial Fluid responsiveness monitors will allow you to detect hypovolemia and provide a margin of safety Ultimately the decision about how to manage intraoperative fluids is based on an individualized cost-benefit ratio 13
Conclusions Thiele RH et al. Perioperative Medicine 5:24, 2016 14