W. J. West4, L. Ladehoff4, K. M. Labib4, C. R. Fiedler4, W. N. Doyle4, A. O. Dumitriu Carcoana4, J. C. Marek4, J. A. Malavet4, C. C. Moodie1, J. R. Garrett1, J. R. Tew1, J. J. Baldonado1,2,3, J. P. Fontaine1,2,3, E. M. Toloza1,2,3 1Moffitt Cancer Center And Research Institute, Thoracic Oncology, Tampa, FL, USA 2University Of South Florida College Of Medicine, Surgery, Tampa, FL, USA 3University Of South Florida College Of Medicine, Oncologic Sciences, Tampa, FL, USA 4University Of South Florida College Of Medicine, Medical Education, Tampa, FL, USA
Introduction: Magnesium is a regulator of vascular tone, thrombosis, and heart rhythm. Low and high postoperative magnesium levels have been tied to increased rates for adverse events and postoperative atrial fibrillation, respectively, following cardiac procedures. We investigated the relationship between postoperative magnesium levels and outcomes following robotic-assisted pulmonary lobectomy (RAPL).
Methods: We retrospectively analyzed consecutive patients who underwent RAPL from September 2010 to March 2022 by one surgeon. We collected and analyzed perioperative magnesium levels at five timepoints: post-anesthesia care unit (PACU), postoperative day one (POD1), lowest postoperative, highest postoperative, and discharge (last recorded value). Serum magnesium levels were classified as low, normal, or high based on a reference range from 1.8 to 2.3 mg/dL. One-way analysis of variance (ANOVA), Kruskal-Wallis H Test, Chi-squared test of independence, and Fisher’s exact test were used to examine relationships between serum magnesium level and preoperative patient characteristics, intraoperative occurrences, and postoperative outcomes, with p≤0.05 as significant.
Results: After examining 722 patients who underwent RAPL, highest postoperative magnesium level was the timepoint associated with the greatest number of postoperative outcomes. Patients whose highest postoperative magnesium level was above the normal range were more likely to develop postoperative arrhythmia, atrial fibrillation, anemia, hypotension, respiratory failure, prolonged air leak >7 days, pneumonia, and any postoperative complication. They also had greater mortality during their hospital stay and within 30 days. Lowest postoperative magnesium level was also tied to numerous postoperative complications. Patients whose lowest postoperative magnesium level was lower than normal range were more likely to develop postoperative shock and multi-organ system failure, prolonged air leak >7 days, pneumonia, and any postoperative complication. Patients also had greater mortality during their hospital stay.
Conclusions: Our results support prior work in cardiac procedures that showed low and high magnesium levels were associated with increased risk for surgical complications. Surgeons should be aware of the relationship between extremely low and high magnesium levels and postoperative complications and mortality following RAPL. Serum magnesium abnormalities should be corrected as needed during management of patients before and after operations with an emphasis on supplementation for low levels that does not lead to excessively elevated levels.
