Two papers published in this month’s issue of Anesthesia & Analgesia, “The Effect of 6% Hydroxyethyl Starch 130/0.4 on Renal Function, Arterial Blood Pressure, and Vasoactive Hormones During Radical Prostatectomy: A Randomized Controlled Trial” and “Hydroxyethyl Starch and Acute Kidney Injury in Orthotopic Liver Transplantation: A Single-Center Retrospective Review” represent two different perspectives on the same question regarding fluid replacement with hydroxyethyl starch. The accompanying editorial asks the critical question: “But Is It Safe? Hydroxyethyl Starch in Perioperative Care.”
In the first manuscript, Dr. Anne Sophie Pinholt Kancir, University Clinic for Nephrology and Hypertension, Department of Medical Research and Medicine, and Department of Anesthesiology, Holstebro Hospital and University of Aarhus, Holstebro, Denmark, and colleagues report on a small prospective randomized trial of HES vs. normal isotonic saline 0.9% as intraoperative volume therapy for patients undergoing radical prostatectomy. Thirty-six patients completed the trial. The investigators found no difference in biochemical markers for acute kidney injury between the two groups. The HES group appeared to be slightly better resuscitated (lower vasopressin levels) while the normal isotonic saline 0.9% group showed a trend towards lower estimated blood loss. In the second manuscript, Dr. William R. Hand, Department of Anesthesia & Perioperative Medicine, Medical University of South Carolina, Charleston, South Carolina, and colleagues performed a complex retrospective analysis of 174 patients undergoing orthotopic liver transplantation, spanning a change in hospital availability from albumin to HES. Three groups (albumin only, HES only, and combined albumin and HES) were examined for evidence of acute kidney injury (AKI) postoperatively. Patients receiving HES alone were at 3 times the risk of developing AKI than those receiving albumin alone. Propensity analysis revealed a dose-dependent risk for AKI in patients receiving HES.
Interpretation of these mixed results should be guided by the thoughts of Dr. Steven Greenberg, Department of Anesthesia, NorthShore University HealthSystem, Evanston, Illinois, and Dr. Avery Tung, Department of Anesthesia and Critical Care, University of Chicago, Chicago, Illinois, the editorialists. They note that the populations studied were not equivalent in risk: only 2.5% of the prostate patients were transfused compared to >90% of the liver transplant group. In their opinion, the risk of HES is likely to be very small – unmeasurably so – in most low-risk populations, but care should be taken in those who have prior kidney disease or are at high risk for transfusion. Along with the authors of both studies, Drs. Greenberg and Tung argue for further prospective research focused specifically on the topic of perioperative volume replacement and appropriately controlled for “goal direction.” They note that many argue that starch should be used for resuscitation but not maintenance, a flaw of many protocolized studies. But if we can’t agree on what constitutes optimum volume status (and we can’t) then we can’t agree about when resuscitation ends and maintenance begins. That makes it harder to study the question.
Taken together, these three publications illustrate how much we still don’t know about optimal fluid resuscitation in the operating room.