title: Calcium Disorders in the Emergency Department: Independent Risk Factors for Mortality.
abstract: BACKGROUND
  Calcium disorders are common in both intensive care units and in patients with chronic kidney disease and are associated with increased morbidity and mortality. It is unknown whether calcium abnormalities in unselected emergency department admissions have an impact on in-hospital mortality.
  
  
  METHODS
  This cross-sectional analysis included all admissions to the Emergency Department at the Inselspital Bern, Switzerland from 2010 to 2011. For hyper- and hypocalcaemic patients with a Mann-Whitney U-test, the differences between subgroups divided by age, length of hospital stay, creatinine, sodium, chloride, phosphate, potassium and magnesium were compared. Associations between calcium disorders and 28-day in-hospital mortality were assessed using the Cox proportional hazard regression model.
  
  
  RESULTS
  8,270 patients with calcium measurements were included in our study. Overall 264 (3.2%) patients died. 150 patients (6.13%) with hypocalcaemia and 7 patients with hypercalcaemia (6.19%) died, in contrast to 104 normocalcaemic patients (1.82%). In univariate analysis, calcium serum levels were associated with sex, mortality and pre-existing diuretic therapy (all p<0.05). In multivariate Cox regression analysis, hypocalcaemia and hypercalcaemia were independent risk factors for mortality (HR 2.00 and HR 1.88, respectively; both p<0.01).
  
  
  CONCLUSIONS
  Both hypocalcaemia and hypercalcaemia are associated with increased 28-day in-hospital mortality in unselected emergency department admissions.
authors.affiliation: Department of Emergency Medicine, Inselspital, University Hospital Bern, Freiburgstrasse, Bern, Switzerland.
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Sauter
authors.affiliation: Department of Emergency Medicine, Inselspital, University Hospital Bern, Freiburgstrasse, Bern, Switzerland.
authors.forename: Gregor
authors.initials: G
authors.lastname: Lindner
authors.affiliation: Department of Emergency Medicine, Inselspital, University Hospital Bern, Freiburgstrasse, Bern, Switzerland.
authors.forename: Sufian S
authors.initials: SS
authors.lastname: Ahmad
authors.affiliation: Centre of Laboratory Medicine, Inselspital, University Hospital Bern, Bern, Switzerland.
authors.forename: Alexander Benedikt
authors.initials: AB
authors.lastname: Leichtle
authors.affiliation: Centre of Laboratory Medicine, Inselspital, University Hospital Bern, Bern, Switzerland.
authors.forename: Georg-Martin
authors.initials: GM
authors.lastname: Fiedler
authors.affiliation: Department of Emergency Medicine, Inselspital, University Hospital Bern, Freiburgstrasse, Bern, Switzerland.
authors.forename: Aristomenis K
authors.initials: AK
authors.lastname: Exadaktylos
authors.affiliation: Department of Emergency Medicine, Inselspital, University Hospital Bern, Freiburgstrasse, Bern, Switzerland.
authors.forename: Dominik G
authors.initials: DG
authors.lastname: Haider
mesh_terms: D002118:Calcium / Q000378:metabolism*; D002712:Chlorides / Q000378:metabolism; D003404:Creatinine / Q000378:metabolism; D003430:Cross-Sectional Studies; D004636:Emergency Service, Hospital; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D006934:Hypercalcemia / Q000150:complications* / Q000378:metabolism; D006996:Hypocalcemia / Q000150:complications* / Q000378:metabolism; D007362:Intensive Care Units; D007902:Length of Stay; D008274:Magnesium / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D011188:Potassium / Q000378:metabolism; D016016:Proportional Hazards Models; D012307:Risk Factors; D012964:Sodium / Q000378:metabolism; D013557:Switzerland
chemical_list: D002712:Chlorides; D012964:Sodium; D003404:Creatinine; D008274:Magnesium; D011188:Potassium; D002118:Calcium