MIAMI BEACH — A soon-to-be-published Cochrane review is expected to indicate the superiority of intraoperative initiation of fluid management protocols and to quantify the link between perioperative complications and postoperative survival, according to one of the study's coauthors.
The review, “Perioperative Increases in Global Blood Flow to Explicit Defined Goals and Outcomes Following Surgery,” gives evidence-based guidance on these two controversial issues, gleaned from “very different” studies with a total of 4,546 patients, Dr. Mark Hamilton reported at a meeting on perioperative medicine sponsored by the University of Miami.
The 22 studies in the review included elective and emergency patients undergoing general, vascular, or cardiac surgery. Overall perioperative mortality was 10.6%.
Use of a fluid protocol was associated with 216 perioperative deaths. There were 265 deaths among patients treated without a protocol (odds ratio, 0.82). This statistically significant reduction in mortality was “quite clear” for the protocol groups vs. controls, Dr. Hamilton said.
The timing of the intervention is significantly more protective if flow-directed therapy is intraoperative vs. preoperative or postoperative, according to the review, although the final answer on the optimal management strategy remains elusive, said Dr. Hamilton, consultant and honorary senior lecturer in anesthesia and intensive care medicine at St. George's Hospital in London. He had no relevant financial disclosures.
Fundamental problems of perioperative fluid therapy include an inability to accurately evaluate blood volume, identify fluid overload, identify hypovolemia, or precisely evaluate tissue perfusion, Dr. Hamilton said.
Multiple organizations have developed guidelines to steer hospitalists, surgeons, and other perioperative clinicians regarding fluid management, but they are backed by varying levels of evidence, he said.
Dr. Hamilton recommended the British Consensus Guidelines on Intravenous Fluid Therapy for Adult Surgical Patients (www.ebpom.org
Another finding is that significant perioperative complications can have a long-term effect on surgery patients.
“This is where it gets more interesting,” Dr. Hamilton said. “This is the most consistent theme in the studies.” A lack of a standard definition for perioperative complications worldwide has impeded previous efforts to compile overall complication rates, he said.
In one study, any of 22 complications in the National Surgical Quality Improvement Program database within 30 days of surgery was the most important factor associated with decreased postoperative survival (Ann. Surg. 2005;242:326–41).
Postoperative complications were associated with a 69% reduction in median survival among 105,951 patients who had surgery between 1991 and 1999, and were more indicative of survival after major surgery than were preoperative or perioperative risk factors.