SAN DIEGO – Patients who have minor elevations in serum creatinine after noncardiac surgery may be more likely to require a longer postoperative hospital stay and face a twofold increased risk of dying during that stay, preliminary data from a German study have shown.
"This is a big problem, because minor kidney dysfunction may not be noticed postoperatively," Dr. Felix Kork said in an interview during a poster session at Kidney Week 2012 "About 2% of people in general have a small increase in serum creatinine. They are at a greater risk of dying and staying longer in the hospital. Therapeutic options are needed to prevent this minor kidney dysfunction perioperatively."
Dr. Felix Kork
Dr. Kork of the department of anesthesiology and intensive care medicine at Charité Hospital in Berlin and his associates retrospectively studied the records of 27,616 patients who underwent noncardiac surgery at Charité between 2006 and 2012. The researchers evaluated perioperative renal function by serum creatinine level.
After doing a multivariate analysis that adjusted for age, comorbidities, renal function, high-risk surgery, and postoperative admission to the ICU, the researchers observed that minor elevations in serum creatinine (defined as a range from 0.25 to 0.50 mg/dL) were independently associated with a prolonged hospital length of stay (HR for early discharge, 0.81) and a twofold increased risk of death during the postoperative hospital stay (OR, 1.99) compared with patients without an increase in serum creatinine level. Both findings were statistically significant.
"While adjusting for covariates, we also found that having received radio contrast agent before surgery is independently associated with a greater risk of mortality and hospital length of stay, whether there was kidney dysfunction after the radio contrast agent or not," Dr. Kork added. "We’re still looking into that [association]. It could be that those patients were sicker."
He acknowledged that the study’s retrospective design is a limitation. Because of this "we can only show the association between the serum creatinine increase and the outcome," he said. "We are planning a prospective study right now." Dr. Kork explained that the current study has been submitted for publication in an undisclosed journal, which will contain more detail about these findings.
Dr. Kork said that he had no relevant financial conflicts to disclose.