Risk factors and optimal predictive scoring system of mortality for children with acute paraquat poisoning

Table 1 Pediatric critical illness score

Parameter	Age < 1 yr	Age ≥ 1 yr	Scores
Heart rate (beats/min)	< 80 or > 180	< 60 or > 160	4
	80-100 or 160-180	60-80 or 140-160	6
	Others	Others	10
Blood pressure (systolic) [kPa (mmHg)]	< 7.5 (55) or > 17.3 (130)	< 8.7 (65) or > 20 (150)	4
	7.5-8.7 (55-65) or 13.3-17.3 (100-130)	8.7-10 (65-75) or 17.3-20 (130-150)	6
	Others	Others	10
Breathing rate (breaths/min)	< 20 or > 70 or irregular breathing	< 15 or > 60 or irregular breathing	4
	20-25 or 40-70	15-20 or 35-60	6
	Others	Others	10
PaO2 [kPa (mmHg)] (no oxygen inhalation)	< 6.7 (50)		4
	6.7-9.3 (50-70)		6
	Others		10
pH	< 7.25 or > 7.55		4
	7.25-7.30 or 7.50-7.55		6
	Others		10
Na+ (mmol/L)	< 120 or > 160		4
	120-130 or 150-160		6
	Others		10
K + (mmol/L)	< 3.0 or > 6.5		4
	3.0-3.5 or 5.5-6.5		6
	Others		10
Scr (μmol/L)	> 159		4
	106-159		6
	Others		10
BUN (mmol/L)	> 14.3		4
	7.1-14.3		6
	Others		10
Hb (g/L)	< 60		4
	60-90		6
	Others		10
Digestive system symptoms	Stress ulcer bleeding and intestinal paralysis		4
	Stress ulcer bleeding		6
	Others		10

pH: Pondus hydrogenii; Na⁺: Serum sodium; K⁺: Serum potassium; Scr: Serum creatinine; BUN: Blood urea nitrogen; Hb: Hemoglobin.

Table 2 The pediatric early warning score

	0	1	2	3
Behavior	Playing; alert; appropriate; at baseline	Sleeping; fussy but consolable	Irritable/inconsolable	Lethargic; confused; reduced response to pain
Cardiovascular status	Pink cap refill 1-2 s	Gray; cap refill 3 s	Gray; cap refill 4 s; tachycardia of 20 beats/min above the normal rate	Gray; mottled; cap refill 5 s; tachycardia of 30 beats/min above the normal rate; bradycardia
Respiratory status	Within normal parameters	Greater than 10 breaths/min above normal parameters; accessory muscle use; 30% FiO2; 3 liters/minute	Greater than 20 breaths/min above normal parameters; retractions; 40% FiO2; 6 liters/minute; tracheostomy- and ventilator- dependent	Below normal parameters with retractions; grunting; 50% FiO2; 8 liters/minute

FiO₂: Fraction of inspiration O₂.

Table 3 Comparison of clinical characteristics between survivors and non-survivors (n = 113)

Variable	Survivors	Non-survivors	P value
Age (yr), n (%)			0.003
≤ 3 yr	22 (25.6)	0 (0.0)
3-6 yr (not including 3 yr)	12 (13.4)	3 (11.1)
6-12 yr (not including 6 yr)	27 (31.2)	10 (37.0)
> 12 yr	25 (29.1)	14 (51.9)
Sex, n (%)			0.039
Female	41 (47.7)	19 (70.4)
Male	45 (52.3)	8 (29.6)
Cause of intoxication, n (%)			0.585
Accidental	68 (79.1)	20 (74.1)
Suicide	18 (20.9)	7 (25.9)
Time to blood purification, n (%)			0.185
< 6 h	3 (5.0)	2 (8.7)
6-12 h	12 (20.0)	7 (30.4)
12-24 h (not including 12 h)	13 (21.7)	5 (21.7)
> 24 h	32 (53.3)	9 (39.1)
Time to consultation, n (%)			0.191
< 6 h	28 (32.6)	11 (40.7)
6-24 h	22 (25.6)	6 (22.2)
> 24 h	36 (41.9)	10 (37.1)
Vomiting, n (%)	30 (34.9)	19 (70.4)	0.001
Abdominal pain, n (%)	14 (16.3)	9 (33.3)	0.055
Oral ulcer, n (%)	32 (37.2)	16 (66.7)	0.043
Gastrointestinal bleeding, n (%)	3 (3.5)	5 (18.5)	0.001
WBC count (× 109/L)	11.27 ± 4.57	15.45 ± 7.15	0.007
PLT count (× 109/L)	267.79 ± 102.52	222.48 ± 79.15	0.038
ALT [M (P25, P75)]	32.5 (25, 42)	99 (41, 494)	< 0.001
AST [M (P25, P75)]	28 (20, 40)	108 (38, 295)	< 0.001
Albumin (g/L)	44.34 ± 5.33	40.54 ± 6.23	0.002
Glucose (mmol/L)	6.60 ± 3.43	6.75 ± 1.31	0.805
Na+ (mmol/L)	137.04 ± 4.84	133.84 ± 6.49	0.024
K+ (mmol/L)	3.72 ± 0.58	3.70 ± 0.668	0.882
Scr (mmol/L)	74.17 ± 74.70	441.04 ± 267.86	< 0.001
BUN (mmol/L)	7.62 ± 6.65	23.06 ± 14.99	< 0.001
PEWS, n (%)			< 0.001
0	66 (78.6)	9 (33.3)
1	12 (14.0)	9 (33.3)
2	5 (5.8)	3 (11.1)
3	1 (1.1)	3 (11.1)
4	1 (1.1)	0 (0.0)
≥ 5	1 (1.1)	3 (11.1)
PCIS	95.57 ± 6.33	83.85 ± 7.74	< 0.001
≤ 70, n (%)	0 (0.0)	2 (7.4)
71-80, n (%)	6 (69.8)	9 (33.3)
> 80, n (%)	80 (93.0)	16 (59.3)

ALT: Alanine aminotransferase; AST: Aspartate aminotransferase; WBC: White blood cell; PLT: Platelet; Scr: Serum creatinine; BUN: Blood urea nitrogen; PCIS: Pediatric critical illness score; PEWS: Pediatric early warning score; Na⁺: Serum sodium; K⁺: Serum potassium.

Table 4 Analysis of mortality due to paraquat poisoning using multivariate logistic regression (n = 113)

Variables	β Coefficient	SE	Odds ratio (95%CI)	P value
ALT	0.024	0.010	1.024 (1.003-1.045)	0.022
PCIS	-0.151	0.046	0.860 (0.785-0.942)	0.001

ALT: Alanine aminotransferase; PCIS: Pediatric critical illness score; SE: Standard error; CI: Confidence interval.

Table 5 Predictive value of risk factors for mortality in children with acute paraquat poisoning (n = 113)

Predictive factors	Sensitivity (%)	Specificity (%)	AUROC (95%CI)	Youden index	P value
ALT	59.26	96.51	0.814 (0.730-0.881)	0.557	< 0.001
PCIS	92.30	82.21	0.905 (0.836-0.952)	0.774	< 0.001
ALT and PCIS	92.59	87.21	0.937 (0.875-0.974)	0.798	< 0.001

ALT: Alanine aminotransferase; PCIS: Pediatric critical illness score; AUROC: Area under the receiver operating characteristic; CI: Confidence interval.