Predictive Value of Ionized Calcium for Prognosis of Sepsis in Very Low Birth Weight Infants

Figures & data

Figure 1 Flow chart of this study.

Table 1 Comparison of Clinical Data of Neonates in Different Prognostic Groups

Variables	Poor Prognosis Group (n=143)		Poor Prognosis Group (n=143)	Good Prognosis Group (Mild Complications or No Morbidity) (n=106)
	Death (n=55)	Severe Morbidity (n=88)
GA (weeks)	29.0(26.4, 30.2)	28.4(27.5, 30.0)	28.5(27.5, 30.0)	30.2(29.1, 30.2)^b
BW (kg)	1.05(0.83, 1.20)	1.09(0.98, 1.24)	1.05(0.95, 1.20)	1.27(1.14, 1.37)^b
Male, n (%)	25(45.5)	54(61.4)	89(62.2)	64(60.4)
Cesarean section, n (%)	27(49.1)	49(55.7)	76(53.1)	77 (72.6)
Temperature (°C)	37.37±0.78	37.49±0.61	37.45±0.68	37.17±0.58
Heart rate (bpm)	160.51±20.54	156.51±20.82	158.97±20.67	159.83±14.80
Laboratory indicators
WBC	4.80(2.85, 10.44)	4.63(3.41, 8.65)	4.70(3.41, 10.57)	5.93(3.83, 11.86)
N (%)	56.8(47.3, 74.6)	52.9(39.3, 64.9)	50.7(32.4, 64.1)	61.24(32.74, 72.30)
PLT(×109/L)	69.0 (49.0, 239.0)^a	212.0(132.3, 293.0)	189.0(64.0, 264.0)	192.5 (125.5, 265.5)^b
Hb(g/L)	117.0(101.5, 156.0)	116.5(92.0, 133.0)	118.5(97.0, 134.3)	118.0 (106.0, 139.0)
hsCRP(mg/L)	7.15(4.25, 23.90)	16.00(1.13, 38.50)	14.86(1.57, 34.44)	8.68 (2.08, 25.00)
PCT (ng/mL)	8.06 (0.87, 39.84)	4.10 (1.25, 20.27)	4.10 (1.20, 28.74)	4.58 (0.47, 13.35)
TP(g/L)	44.80(39.85, 48.80)	44.00(39.47, 47.50)	44.00(39.70, 47.80)	44.60(41.20, 48.00)
ALB(g/L)	25.8 (25.0, 31.3)^a	26.8 (24.6, 30.6)	26.1 (24.6, 30.7)	28.6 (26.5, 32.0)^b
TBIL (umol/L)	93.4 (44.6, 153.9)	85.7 (42.8, 107.9)	86.6 (44.2, 128.1)	78.0 (38.6, 116.7)
Na(mmol/L)	137(135, 143)	137(134, 141)	137(135, 141)	137(136, 139)
K(mmol/L)	4.80(4.65, 5.95)	4.38(3.90, 5.10)	4.55(4.20, 5.13)	4.20(3.80, 4.83)^b
iCa(mg/dL)	3.40(2.92, 4.56)^a	3.84(3.36, 5.24)	3.76(3.32, 5.24)	5.20(3.92, 5.68)^b
TCa(mmol/L)	2.33(2.09, 2.43)	2.20 (1.98, 2.32)	2.28 (2.00, 2.34)	2.31(2.24, 2.41)^b
PH	7.26(7.20, 7.37)	7.33(7.27, 7.41)	7.32(7.25, 7.40)	7.33(7.26, 7.39)
P(mmol/L)	2.05±0.78	1.99±0.63	2.02±0.71	1.82±0.46^b
Mg(mmol/L)	0.98±0.29	0.88±0.20	0.92±0.25	1.00±0.94
Maternal gestational factors
GDM	12(21.8)	19(21.6)	31(21.7)	24(22.6)
PROM, n (%)	13(23.6)	21(23.9)	34(23.8)	31(29.2)

Notes: All values are presented as the mean± SD or n (%) or as the median (interquartile range). ^aP < 0.05 for death vs severe morbidity. ^bP < 0.05 poor prognosis group vs good prognosis group.

Abbreviations: GA, gestational age; BW, birth weight; WBC, white blood cell; N, neutrophils; PLT, platelet; Hct, hematocrit; Hb, hemoglobin; hsCRP, high sensitivity C-reactive protein; PCT, procalcitonin; TP, total protein; ALB, albumin; TBIL, total bilirubin; Na, sodium; K, potassium; iCa, ionized calcium; TCa, total calcium; P, Phosphate; Mg, magnesium; PROM, premature rupture of membranes.

Figure 2 The levels of BW, GA, ALB, PLT, Total Ca, iCa, and K in the mild complications or no complications group, the severe complications group, and the death group. (A) Mild complications or no complications group; (B) severe complications group; (C) the death group.

Abbreviations: BW, birth weight; GA, gestational age; ALB, albumin; PLT, platelet; TCa, total calcium; iCa, ionized calcium; K, potassium.

Table 2 Clinical and Demographic Characteristics in the Hypocalcemia and Normal iCa Groups

	iCa≥4mg/dl (n=133)	iCa<4mg/dl (n=116)	P value
Male, n (%)	77(57.9)	66(56.9)	0.874
Laboratory indicators
HsCRP (mg/L)	14.87(0.90, 43.13)	5.27(0.61, 23.09)	0.051
PCT (ng/mL)	1.52(0.17, 17.92)	1.62(0.01, 17.11)	0.351
Comorbidities
Pulmonary hemorrhage, n (%)	9(6.8)	15(12.9)	0.100
BPD, n (%)	17(12.8)	64(55.2)	<0.001
NEC, n (%)	19(14.3)	20(17.2)	0.503
ROP, n (%)	26(19.7)	37(31.9)	0.028
Cerebral injury, n (%)	11(8.3)	24(20.9)	<0.001
Treatment outcomes
Death, n (%)	17(12.8)	38(32.8)	<0.001
Severe morbidity, n (%)	36(27.1)	52(44.8)	<0.001
Mild complications or no morbidity, n (%)	80(60.2)	26(22.4)	<0.001
Prism III	6.00(4.00, 9.00)	14.00(11.00, 18.00)	<0.001
Length of hospitalization(days)	50.00(38.75, 63.00)	56.00(37.25, 75.00)	0.220

Notes: All Values are presented as n (%) or as the median (interquartile range). Cerebral injury refers to grade 3 or 4 intraventricular hemorrhage and periventricular leukomalacia; ROP refers to grade 3 or higher retinopathy of prematurity; NEC refers to grade 3 necrotizing enterocolitis; BPD refers to severe bronchopulmonary dysplasia.

Table 3 Logistic Analysis Results of Predictors for Poor Outcomes in VLBWI with Sepsis

Variables	Univariate		Multivariate
	OR (95% CI)	p	OR (95% CI)	p
GA	0.641 (0.548–0.749)	<0.001	0.743 (0.005–0.208)	0.002
BW	0.012 (0.003–0.058)	<0.001	0.031 (0.614–0.899)	<0.001
PLT	0.999 (0.997–1.001)	0.049	1.000 (0.997–1.003)	0.917
ALB	0.946(0.897–0.997)	0.038	0.929 (0.869–0.994)	0.032
Blood potassium	1.546 (1.191–2.007)	0.001	1.235 (0.878–1.738)	0.226
Blood phosphorus	1.754(1.138–2.703)	0.011	1.422 (0.772–2.617)	0.258
TCa	0.283 (0.126–0.638)	0.002	2.008 (0.627–6.432)	0.240
iCa	0.461(0.355–0.600)	<0.001	0.558(0.406–0.768)	<0.001

Abbreviations: GA, gestational age; BW, birth weight; PLT, platelet; ALB, albumin; iCa, ionized calcium; TCa, total calcium.

Table 4 Results of Stepwise Logistic Regression Analysis of Predictors for Poor Outcomes in VLBWI with Sepsis

Variables	B	SE	Wald value	OR (95% CI)	P value
GA	−0.317	0.091	12.120	0.728(0.609–0.871)	<0.001
BW	−0.003	0.001	11.696	0.997(0.995–0.999)	0.001
ALB	−0.069	0.032	4.625	0.933(0.877–0.994)	0.032
iCa	−0.599	0.144	17.279	0.550(0.414–0.729)	<0.001

Abbreviations: GA, gestational age; BW, birth weight; ALB, albumin; iCa, ionized calcium; SE, standard error.

Table 5 Logistic Analysis Results of Predictors for Death in the Poor Prognosis Group

Variables	Univariate		Multivariate
	OR (95% CI)	p	OR (95% CI)	p
PLT	0.995 (0.992–0.998)	0.003	0.994(0.991–0.998)	0.001
ALB	0.912(0.849–0.981)	0.013	0.939(0.869–1.015)	0.114
Blood potassium	1.607 (1.182–2.183)	0.002	1.741(1.194–2.538)	0.004
iCa	0.569(0.395–0.818)	0.002	0.659(0.445–0.977)	0.038

Abbreviations: PLT, platelet; ALB, albumin; iCa, ionized calcium.

Figure 3 (A) ROC curve for iCa, ALB, BW, GA, PRISM III in predicting poor prognosis in VLBWI with sepsis; (B) ROC curve for iCa, K, PLT, PRISM III predicting death in the poor prognosis group.

Abbreviations: BW, birth weight; GA, gestational age; ALB, albumin; PLT, platelet; iCa, ionized calcium; K, potassium.

Figure 4 Correlation of iCa levels with PRISM III. (A) iCa levels in different PRISM III score groups; (B) scatter plot of correlation between iCa and PRISM III score.