Daniel Dante Yeh1, Nalin Chokengarmwong2, Yuchiao Chang3, Liyang Yu3, Colleen Arsenault4, Joseph Rudolf5, Elizabeth Lee-Lewandrowski5, Kent Lewandrowski5. 1. Massachusetts General Hospital, Department of Surgery, Division of Trauma, Emergency Surgery, and Surgical Critical Care, United States. Electronic address: dxy154@miami.edu. 2. Massachusetts General Hospital, Department of Surgery, Division of Trauma, Emergency Surgery, and Surgical Critical Care, United States. 3. Massachusetts General Hospital, Department of Medicine, United States. 4. Massachusetts General Hospital, Surgical Intensive Care Unit, United States. 5. Massachusetts General Hospital, Department of Pathology, United States.
Abstract
PURPOSE: Ionized fraction (iMg) is the physiologically active form of magnesium (Mg); total Mg may not accurately reflect iMg status. Erroneously "low" Mg levels may result in unnecessary repetitive testing. MATERIALS AND METHODS: From 11/2015 to 01/2016, patients ordered for Mg from a pilot ICU also had iMg tested. Weighted kappa statistic was used to assess agreement between Mg categories (low, normal, high). Predictors of unnecessary repeated Mg testing and repletion using data were explored through logistic regression models using GEE techniques to account for repeated measurements in both bivariate and multivariable analyses. RESULTS: There were 470Mg/iMg paired measurements from 173 patients. The weighted kappa statistic was 0.35 (95%CI 0.27-0.43) indicating poor agreement in assessment of magnesium status. Of the 34Mg samples reported as "low", only 6 (18%) were considered "low" using concurrent iMg testing. In the multivariable models, history of atrial fibrillation (aOR=1.61, 95%CI 1.16-2.21, p=0.004) and concomitant metoclopramide (aOR=1.71, 95%CI 1.03-2.81, p=0.036) were significant predictors of unnecessary repeat Mg testing. CONCLUSIONS: In the surgical ICU, categorical agreement (low, normal, high) was poor between Mg and iMg. Over 80% of "low" total Mg values are erroneous and may result in unnecessary additional measurements and repletion.
PURPOSE:Ionized fraction (iMg) is the physiologically active form of magnesium (Mg); total Mg may not accurately reflect iMg status. Erroneously "low" Mg levels may result in unnecessary repetitive testing. MATERIALS AND METHODS: From 11/2015 to 01/2016, patients ordered for Mg from a pilot ICU also had iMg tested. Weighted kappa statistic was used to assess agreement between Mg categories (low, normal, high). Predictors of unnecessary repeated Mg testing and repletion using data were explored through logistic regression models using GEE techniques to account for repeated measurements in both bivariate and multivariable analyses. RESULTS: There were 470Mg/iMg paired measurements from 173 patients. The weighted kappa statistic was 0.35 (95%CI 0.27-0.43) indicating poor agreement in assessment of magnesium status. Of the 34Mg samples reported as "low", only 6 (18%) were considered "low" using concurrent iMg testing. In the multivariable models, history of atrial fibrillation (aOR=1.61, 95%CI 1.16-2.21, p=0.004) and concomitant metoclopramide (aOR=1.71, 95%CI 1.03-2.81, p=0.036) were significant predictors of unnecessary repeat Mg testing. CONCLUSIONS: In the surgical ICU, categorical agreement (low, normal, high) was poor between Mg and iMg. Over 80% of "low" total Mg values are erroneous and may result in unnecessary additional measurements and repletion.
Authors: Jiada Zhan; Taylor C Wallace; Sarah J Butts; Sisi Cao; Velarie Ansu; Lisa A Spence; Connie M Weaver; Nana Gletsu-Miller Journal: Nutrients Date: 2020-04-28 Impact factor: 5.717
Authors: Mary R Rooney; Kyle D Rudser; Alvaro Alonso; Lisa Harnack; Amy K Saenger; Pamela L Lutsey Journal: Nutrients Date: 2020-01-20 Impact factor: 5.717