When it comes to surgery for patients with hip fractures, earlier is better. A database analysis by a team of Cleveland Clinic researchers concluded that for every 10-hour increase in time from hospital admission to surgery, one-year mortality in these patients increased by 5%.
“There is considerable debate regarding the timing of surgery after hip fracture,” said Kamal Maheshwari, MD, MPH, director of the Center of Perioperative Intelligence, Anesthesia Institute, at the Cleveland Clinic. “And even though there’s been quite a bit of work published on the topic, the results are inconsistent. Furthermore, there are no guidelines—at least in the U.S.—with respect to when hip fracture surgery should be performed.
“With all these unanswered questions, we were struggling to figure out a time frame for surgery when creating our own care path for these individuals,” Dr. Maheshwari said. “So we decided to look at our own data, with a focus on long-term outcomes, to determine the best course of action.”
With that in mind, Dr. Maheshwari and his colleagues searched the Cleveland Clinic Perioperative Health Documentation System, identifying 720 patients (>65 years) who underwent hip fracture surgery at their institution between March 25, 2005, and Feb. 28, 2015. Patients were identified through International Classification of Diseases, Ninth Revision diagnosis and procedure codes, as well as Current Procedural Terminology codes. Multivariate logistic regression was used to adjust for baseline clinical status and surgical factors.
As Dr. Maheshwari reported at the 2016 annual meeting of the American Society of Anesthesiologists (abstract BOC06), the median time from hospital admission to the start of the operation was 30 hours. A total of 159 patients (22%) died within one year of their hip fracture repair procedure. Delaying surgery was significantly associated with increased one-year mortality after adjusting for a variety of potential confounders (Table); the estimated odds ratio was 1.05 (95% CI, 1.02-1.08) for each 10-hour increase in surgery time (P=0.001). Perhaps not surprisingly, the analysis also revealed a linear relationship between the time to surgery and one-year mortality.
“The analysis didn’t have power to really make a statement that one particular time frame was better or worse than another,” Dr. Maheshwari said. “Nevertheless, we did find we had a linear relationship between time to surgery and one-year mortality.
“Given the data and knowing the difficulty in performing a prospective trial in these patients, we think that hip fracture should be treated with the same urgency as other time-sensitive pathologies, and we should try to make protocols that reflect that urgency,” Dr. Maheshwari advised.
An audience member questioned whether the trial would have been more accurate had it used the time of fracture as time zero rather than hospital admission.
“That’s actually one of the primary limitations of this database study: We didn’t know exactly when the fracture occurred,” Dr. Maheshwari replied. “That said, in talking to clinicians in our orthopedic surgery group, it seems that patients who have hip fractures requiring surgery usually come to the hospital as soon as possible.”
Gilbert Blaise, MD, professor of anesthesiology at the University of Montreal, wondered why the time to surgery seems to have such a profound effect on one-year mortality. “Is it possibly due to thrombosis or thromboembolism?” Dr. Blaise asked.
“The pathophysiology of hip fracture is such that once you have a fracture, it sets off an inflammatory process that affects multiple organ systems,” Dr. Maheshwari answered. “Plus, these patients, most of whom are in the geriatric age group, have limited mobility after surgery. So if you take these two factors together, the chances of deep vein thrombosis or pulmonary embolism increases significantly.”