General anesthesia is frequently associated with intraoperative hypotension. Generally speaking, decreased sympathetic outflow produces vasodilation and myocardial depression, redistributing blood to the periphery. Most anesthesia providers prevent or treat the resulting hypotension by administration of a fluid bolus, some of which is eliminated by the kidneys at the end of the procedure as the cardiovascular function returns to normal.
A growing body of evidence suggests that volume overload may have negative effects on outcome. For example, one study demonstrated that the use of esophageal Doppler to aid in fluid management resulted in less fluids being administered, fewer postoperative complications, and a shorter length of stay. [1
] On the other hand, hypovolemia may cause hypoperfusion and result in a greater risk of complications, as suggested by a recent study by Futier et al. In this study, patients who received a restrictive fluid regimen had a higher risk of anastomosis failure and sepsis.[2
] So, is it possible to reduce the risk of fluid overload while also reducing the amount of fluid we give during surgery?
In the March issue of Anesthesiology
, Kiefer et al. report the results of a prospective, randomized, controlled trial of peristaltic lower extremity compression.[3
] Seventy patients scheduled for minor otorhinolaryngology (ENT) surgery were randomly assigned to intermittent peristaltic compression of the lower extremities or placebo. Study patients wore 12-chamber cuffs on each lower extremity. The cuffs were designed to compress the lower extremity stepwise from the foot through the upper thigh. Both groups received fluids according to a regimen that included a baseline crystalloid infusion, 250 mL crystalloid boluses for hypovolemia as manifested by changes in vital signs, and a colloid bolus for blood loss greater than 250 mL. The total amount of fluid was capped at 2,500 mL. Interestingly, both groups experienced a similar drop in blood pressure immediately after induction of general anesthesia. The group receiving peristaltic compression, however, experienced fewer episodes of systemic arterial hypotension, received a significantly smaller amount of fluid, and had fewer events that triggered fluid administration. One surprising finding was the duration of the effect. The effect of placing a patient into the Trendelenburg position lasts for only a few minutes [4
] while lower extremity compression seemed to improve the patients’ hemodynamics for the entire procedure. The use of peristaltic lower extremity compression, combined with a protocol-driven fluid management strategy, improved hemodynamic stability in the study patients.
It is important to note that this study did not examine outcomes; only healthy patients undergoing minor ENT surgery participated. Moreover, the amount of fluid given was relatively small compared to that which would be given for many other kinds of procedures (e.g., an open intra-abdominal surgery). Still, pneumatic compression of the lower extremities is a relatively benign intervention in most cases, and this study suggests that using this technique may help to reduce the amount of fluid given during surgery. If, as some recent literature indicates, avoiding fluid overload may improve outcome, lower extremity compression is certainly warrants a closer examination. Of course, your comments
are welcome. You can also click on the comment link below.
1. Noblett SE, Snowden CP, Shenton BK, Horgan AF: Randomized clinical trial assessing the effect of Doppler-optimized fluid management on outcome after elective colorectal resection. Br J Surg 2006; 93: 1069-76
2. Futier E, Constantin JM, Petit A, Chanques G, Kwiatkowski F, Flamein R, Slim K, Sapin V, Jaber S, Bazin JE: Conservative vs restrictive individualized goal-directed fluid replacement strategy in major abdominal surgery: A prospective randomized trial. Arch Surg 2010; 145: 1193-200
3. Kiefer N, Theis J, Putensen-Himmer G, Hoeft A, Zenker S: Peristaltic Pneumatic Compression of the Legs Reduces Fluid Demand and Improves Hemodynamic Stability during Surgery: A Randomized, Prospective Study. Anesthesiology 2011; 114: 536-44
4. Gaffney FA, Bastian BC, Thal ER, Atkins JM, Blomqvist CG: Passive leg raising does not produce a significant or sustained autotransfusion effect. J Trauma 1982; 22: 190-3
Posted by Keith J Ruskin, M.D.