LAUSR

OBJECTIVES To examine the influence of serum magnesium on 30-day mortality and cardiac and noncardiac morbidity. DESIGN Retrospective cross-sectional observational study of routinely collected prospective data. SETTING Single-center tertiary vascular center in the United Kingdom. PARTICIPANTS All patients undergoing arterial peripheral vascular surgery during an unplanned admission. INTERVENTIONS Observational, no interventions implemented. MEASUREMENTS AND MAIN RESULTS In the study, n = 197. One hundred thirty-eight were male (70.1%). Median age at procedure was 70.0 years (interquartile range 20.0). Of those with a documented history, 37.9% had diabetes, 81.7% had a smoking history, 63.7% had hypertension, and 26.5% had known ischemic heart disease or heart failure. There was a significant perioperative change in magnesium (p < 0.001), calcium (p < 0.001), and creatinine (p = 0.004), with no significant alteration in potassium (p = 0.096). Thirty-day mortality was 4.6%. Thirty-day cardiac morbidity was 4.1%. Thirty-day noncardiac morbidity was 32.3%. Postoperative magnesium was independently predictive for 30-day mortality (p = 0.02, odds ratio [OR] 0.96, 95% confidence interval [CI] 0.94-0.99) and cardiac morbidity (p = 0.03, OR 0.97, 95% CI 0.95-1.00). Only a previous smoking history was independently predictive of noncardiac morbidity (p = 0.03, OR 9.67, 95% CI 1.20-78.15). CONCLUSION Perioperative changes in serum magnesium may have an influence on short-term mortality and cardiac complications. This should be considered in the management of patients undergoing unplanned peripheral vascular surgery; however, further research is needed to examine the benefit of supplementation perioperatively and to explore the exact mechanisms.