Serum magnesium as a prognostic marker

1. JAPI
Volume 70
May,2022

2. INTRODUCTION
• Magnesium is essential for human health, and ionized magnesium
is involved in the interaction of more than 300 enzyme reactions
and is important for electrolyte homeostasis, membrane stability,
cell division, and generation of action potentials
• Magnesium dysregulation mainly impacts neuromuscular and
cardiovascular functions

3. • The incidence of hypomagnesemia varies from 20% to 65% in
intensive care unit (ICU) patients
• Hypomagnesemia may present as tetany, vertigo, reversible
psychiatric aberrations, seizures, cardiac arrhythmias, hypertension,
muscular weakness, acute cerebral ischemia and asthma
• The pathology of magnesium deficiencies is multifactorial including
gastrointestinal disorders, renal loss, renal diseases, drug-induced
loss, metabolic acidosis, and other causes

4. • In addition, critically ill patients have several potential risks of
magnesium dysregulation
• It was significantly associated with increased and prolonged need for
mechanical ventilation, difficulty to wean, prolonged ICU stay and
increased mortality in critically ill patients

5. • Hypermagnesemia is less common and mostly due to renal failure or
iatrogenic.
• Prevalence of hypermagnesemia was reported to be 7.3%.
• It can lead to severe muscle weakness, respiratory depression,
hypotension, cardiac arrhythmia and ultimately progress to cardiac
arrest.
• Many studies found that only hypomagnesemia , but not
hypermagnesemia is linked with increased mortality.

6. • However, reports of mortality due to magnesium dysregulation in the
critical care setting are controversial.
• Also, it is unknown whether comorbidities of the study population
has any effect on this association.
• Whether hypomagnesemia directly contributes to cellular alterations
leading to increased mortality, morbidity and poor patient outcome in
critically ill patients or it is just a marker of critical illness, is not clear.

7. • Hence, an attempt was made to study serum magnesium levels in
critically ill patients on admission in ICU and its correlation with
patient’s need and duration for ventilator support, duration of ICU
stay, incidence of cardiac arrhythmias and mortality.

8. OBJECTIVES
• To study serum magnesium levels in critically ill patients on admission
in intensive care unit (ICU) and its correlation with
Patient’s need and duration for ventilator support
Duration of ICU stay
Incidence of cardiac arrhythmias
Mortality

9. INCLUSION CRITERIA
• Two hundred forty six critically ill patients admitted in ICU with
APACHE II scores>10, and aged between 18 years and 80 years of
both genders were included
EXCLUSION CRITERIA
• Patients who received magnesium supplements, diuretics and
aminoglycosides or blood transfusions prior to ICU admission
• Chronic alcoholics
• Pregnant women with eclamptic-seizures

10. MATERIALS AND METHODS
• Two hundred forty six critically ill patients admitted in ICU with Acute
Physiology and Chronic Health Evaluation (APACHE) II scores>10, were
included for this prospective observational study
• Serum total magnesium level was measured at the time of admission
to ICU by methyl thymol blue method

11. • The patients were divided into three groups based on serum
magnesium levels:
• Group 1: The patients with Mg level with normal range 1.7-2.4 mg/dL
(normal magnesium level).
• Group 2: The patients with Mg level less than 1.7 mg/dL
(hypomagnesemia).
• Group 3 : The patients with Mg level more than 2.4mg/dL
(hypermagnesemia).

12. • Patients detected with hypomagnesemia/hypermagnesemia were
treated as per the standard guidelines .
• Primary outcome measure was ICU mortality
• Secondary outcome measures were patient’s need and duration for
ventilator support, duration of ICU stay, and incidence of cardiac
arrhythmias
• Categorical and continuous variables were tested using Chi-
square/Fisher’s exact test and analysis of variance respectively.
Multivariate logistic regression analysis was carried out to determine
association of serum magnesium levels with ICU mortality

13. RESULTS
• Incidence of ICU mortality was significantly higher in group of
patients with hypomagnesemia compared to those with normal
magnesium levels
• Hypomagnesemia was associated with need and longer duration of
ventilator support, longer duration of ICU stay, higher APACHE II
score, QTc prolongation, higher incidence of cardiac arrhythmias
compared to patients with normal magnesium levels
• Hypomagnesemia was an independent and statistically significant
determinant of ICU mortality

16. CONCLUSIONS
• Incidence of ICU mortality was significantly higher in group of patients
with hypomagnesemia compared to those with normal magnesium
levels
• Hypomagnesemia was associated with a need and longer duration of
ventilator support, longer duration of ICU stay, higher APACHE II
score, QTc prolongation, higher incidence of VPCs and VT compared
to patients with normal magnesium levels
• Hypomagnesemia was an independent and statistically significant
determinant of increase in ICU mortality

17. LIMITATIONS
• Apart from serum magnesium, confounding factors such as presence
of other electrolyte imbalance like serum sodium, potassium, calcium
and phosphorus, which are known to occur in critically ill patients can
impact prolonged ICU stay, need of mechanical ventilation, increased
days on ventilator, arrhythmias and mortality were not taken into
account in this study
• The effects of the changes in the magnesium levels during the course
of ICU stay on the outcome were also not studied

18. Conclusions Citation
Mg deficiency is common in critically ill patients,
may lead to secondary hypokalemia and
hypocalcemia, and severe neuromuscular and
cardiovascular clinical manifestations.
Hansen, BA., Bruserud, Ø. Hypomagnesemia in
critically ill patients. j intensive care 6, 21 (2018).
https://doi.org/10.1186/s40560-018-0291-y
Collectively, our data indicated that
hypomagnesemia appears associated with greater
risk of mortality, sepsis, mechanical ventilation, and
the length of ICU stay in patients admitted to ICU.
Jiang, Pan; Lv, Qiurong; Lai, Tianwen; Xu, Feng. Does
Hypomagnesemia Impact on the Outcome of
Patients Admitted to the Intensive Care Unit? A
Systematic Review and Meta-Analysis. SHOCK:
March 2017 - Volume 47 - Issue 3
Hypomagnesemia is associated with significant
increase in the risk of mechanical ventilation and
prolonged ICU stay.
Zeineldin, Khaled H.∗; Kandeel, Ahmed; Omar, Emad;
Sabry, Sherif. Effect of Hypomagnesaemia on
Critically Ill Patients: A Retrospective Study. The
Egyptian Journal of Critical Care Medicine: June
2022 - Volume 9 - Issue 2
Statistically significant association of
hypomagnesaemia was found with hypocalcaemia,
hypoalbuminaemia, septicaemia, diabetes and
chronic alcoholism. Higher APACHE II score is
associated with higher mortality and more length of
stay in ICU among the cases of hypomagnesaemia
International Journal of Advances in Medicine
Pannem RB et al. Int J Adv Med. 2018 Dec;5(6):1347-
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19. THANK YOU