J Endocrinol Metab

Journal of Endocrinology and Metabolism, ISSN 1923-2861 print, 1923-287X online, Open Access

Article copyright, the authors; Journal compilation copyright, J Endocrinol Metab and Elmer Press Inc

Journal website https://www.jofem.org

Original Article

Volume 11, Number 5, October 2021, pages 108-114

Total Calcium and Ionized Calcium (pH = 7.4) Tests Are Equal When Screening Patients for Hypercalcemia at Admission in the Emergency Department: A Retrospective Descriptive Study

Figure 1. Distribution of CaI and CaT in 17,838 admissions. Unbroken lines represent reference limits for CaT and CaI. Dotted lines represent the limits for hypercalcemia. CaT: total calcium; CaI: ionized calcium (pH = 7.4).

**Table 1.** Admissions According to Levels of CaT and CaI in mmol/L
	CaT	CaI
^aMismatches. ^bDiscrepancies. CaT: total calcium; CaI: ionized calcium (pH = 7.4).
CaI
≥ 1.45	0^a	17^a	99	82	198
1.33 - 1.44	1^b	1,490^b	523	15	2,029
1.18 - 1.32	751	12,935	239^b	3^a	13,928
< 1.18	832	850	1^b	0^a	1,683
CaT
Total	1,584	15,292	862	100	17,838

Table 1. Admissions According to Levels of CaT and CaI in mmol/L

CaT

CaI

< 2.15

2.15 - 2.51

2.52 - 2.76

≥ 2.77

Total

^aMismatches. ^bDiscrepancies. CaT: total calcium; CaI: ionized calcium (pH = 7.4).

CaI

≥ 1.45

0^a

17^a

198

1.33 - 1.44

1^b

1,490^b

523

2,029

1.18 - 1.32

751

12,935

239^b

3^a

13,928

< 1.18

832

850

1^b

0^a

1,683

CaT

Total

1,584

15,292

862

100

17,838

**Table 2.** Mismatches
Patient no.	Gender	Age (years)	CaT (mmol/L)	CaI (mmol/L)	Albumin (g/L)	Creatinine (µmol/L)/eGFR (mL/min/1.73 m²)	Course for admission	Prior relevant comorbidity	Reason for hypercalcemia	Clinical relevance
^aResults outside reference limits. CaT: total calcium; CaI: ionized calcium (pH = 7.4); eGFR: estimated glomerular filtration rate; PHPT: primary hyperparathyroidism; COPD: chronic obstructive pulmonary disease; FHH: familial hypocalciuric hypercalcemia; GEJ: gastroesophageal junction; CKD: chronic kidney disease; NET: neuroendocrine tumor.
1	F	90.9	2.41	1.50^a	26^a	61/77	Urine retention	PHPT	PHPT	No
2	M	50.7	2.48	1.46^a	41	81/> 90	Abdominal pain	One kidney	PHPT	Yes
3	M	92.7	2.46	1.48^a	32^a	64/81	Thorax pain	None	PHPT	Yes
4	F	70.7	2.47	1.46^a	25^a	53/> 90	Pneumonia	Disseminated breast cancer (bone metastasis)	Malignancy/bone metastasis	No
5	F	89	2.51	1.48^a	33^a	72/64	Pneumonia	Osteoporosis	Unknown	No
6	F	57.5	2.51	1.48^a	40	58/> 90	Chest pain/paresthesia in hands	None	Unknown	No
7	F	93.2	2.36	1.52^a	25^a	117/35^a	Impaired general condition, fall	Multiple myeloma, terminal	Multiple myeloma, CKD	No
			2.48	1.59^a	26^a	120/34^a
8	F	74.6	2.5	1.50^a	34	54/90	COPD	FHH, osteoporosis	FHH	No
9	F	53.6	2.5	1.45^a	40	47/> 90	Impaired general condition	Disseminated GEJ cancer (no known bone metastasis)	Malignancy/bone metastasis	No
10	M	72.2	2.49	1.54^a	30^a	101/64	Fever	PHPT	PHPT	No
11	F	67	2.49	1.46^a	39	87/60	Pneumonia	PHPT	PHPT	No
12	F	81.8	2.46	1.49^a	22^a	48/88	Impaired general condition, pneumonia	Osteoporosis	Unknown	No
13	F	57.4	2.44	1.46^a	28^a	225/20^a	Erysipelas	CKD, thyrotoxicosis	CKD	No
14	F	90	2.51	1.52^a	27^a	78/59	Impaired general condition, erysipelas	None	Calcium supplement + dehydration	No
15	F	79.8	2.43	1.45^a	26^a	36/> 90	Urine tract infection	None	Calcium supplement + dehydration	No
16	F	53.9	2.44	1.45^a	41	54/> 90	Abdominal pain, operation showed NET	None	Unknown	Uncertain
17	F	57	2.99^a	1.32	43	252/18^a	Dehydration	None	Dehydration	No
18	M	68.2	2.9^a	1.27	44	103/64	Perforated ulcer	Hypercalcemia, unknown reason	Calcium metabolic disease?	No
19	M	66.2	2.78^a	1.27	47	935/5^a	Inguinal pain	Terminal CKD, dialysis	CKD	No

Table 2. Mismatches

Patient no.

Gender

Age (years)

CaT (mmol/L)

CaI (mmol/L)

Albumin (g/L)

Creatinine (µmol/L)/eGFR (mL/min/1.73 m²)

Course for admission

Prior relevant comorbidity

Reason for hypercalcemia

Clinical relevance

^aResults outside reference limits. CaT: total calcium; CaI: ionized calcium (pH = 7.4); eGFR: estimated glomerular filtration rate; PHPT: primary hyperparathyroidism; COPD: chronic obstructive pulmonary disease; FHH: familial hypocalciuric hypercalcemia; GEJ: gastroesophageal junction; CKD: chronic kidney disease; NET: neuroendocrine tumor.

90.9

2.41

1.50^a

26^a

61/77

Urine retention

PHPT

50.7

2.48

1.46^a

81/> 90

Abdominal pain

One kidney

PHPT

Yes

92.7

2.46

1.48^a

32^a

64/81

Thorax pain

None

PHPT

Yes

70.7

2.47

1.46^a

25^a

53/> 90

Pneumonia

Disseminated breast cancer (bone metastasis)

Malignancy/bone metastasis

2.51

1.48^a

33^a

72/64

Pneumonia

Osteoporosis

Unknown

57.5

2.51

1.48^a

58/> 90

Chest pain/paresthesia in hands

None

Unknown

93.2

2.36

1.52^a

25^a

117/35^a

Impaired general condition, fall

Multiple myeloma, terminal

Multiple myeloma, CKD

2.48

1.59^a

26^a

120/34^a

74.6

2.5

1.50^a

54/90

COPD

FHH, osteoporosis

FHH

53.6

2.5

1.45^a

47/> 90

Impaired general condition

Disseminated GEJ cancer (no known bone metastasis)

Malignancy/bone metastasis

72.2

2.49

1.54^a

30^a

101/64

Fever

PHPT

2.49

1.46^a

87/60

Pneumonia

PHPT

81.8

2.46

1.49^a

22^a

48/88

Impaired general condition, pneumonia

Osteoporosis

Unknown

57.4

2.44

1.46^a

28^a

225/20^a

Erysipelas

CKD, thyrotoxicosis

CKD

2.51

1.52^a

27^a

78/59

Impaired general condition, erysipelas

None

Calcium supplement + dehydration

79.8

2.43

1.45^a

26^a

36/> 90

Urine tract infection

None

Calcium supplement + dehydration

53.9

2.44

1.45^a

54/> 90

Abdominal pain, operation showed NET

None

Unknown

Uncertain

2.99^a

1.32

252/18^a

Dehydration

None

Dehydration

68.2

2.9^a

1.27

103/64

Perforated ulcer

Hypercalcemia, unknown reason

Calcium metabolic disease?

66.2

2.78^a

1.27

935/5^a

Inguinal pain

Terminal CKD, dialysis

CKD