A new perspective of the risk of caustic substance ingestion: the outcomes of 468 patients in one North Taiwan medical center within 20 years

Figures & data

Figure 1. Diagram of the study population enrollment. CGMH, Chang Gung Memorial Hospital; EGD, esophagogastroduodenoscopy.

Table 1. Demographic characteristics of the enrolled patients with caustic substance ingestion.

Variables	EGD grade
	0/1/2a (%) (n = 193)	2b/3a/3b (%) (n = 275)	p-Value
Elderly (age ≥ 65)	20 (10.4)	60 (21.8)	0.001
Female	92 (47.7)	161 (58.5)	0.020
Strong caustic substances (pH < 2 or > 12)	81 (42.0)	226 (82.2)	<0.001
Strong acids, pH <2	64 (33.2)	173 (62.9)	<0.001
Strong alkalis, pH >12	17 (8.8)	53 (19.3)	0.002
Ingested dose, mL			0.0496
1–99	97 (50.3)	113 (41.1)
≥100	96 (49.7)	162 (58.9)
Intentional ingestion	138 (71.5)	221 (80.4)	0.026
Previous suicide attempts	16 (8.3)	21 (7.6)	0.796
Psychiatric comorbidities	84 (43.5)	141 (51.3)	0.099
Depressive disorders	44 (22.8)	83 (30.2)	0.077
Acute stress disorder/adjustment disorder	20 (10.4)	35 (12.7)	0.434
Schizophrenia spectrum disorders	13 (6.7)	18 (6.5)	0.935
Bipolar disorders	8 (4.1)	9 (3.3)	0.620
Generalized anxiety disorder	3 (1.6)	12 (4.4)	0.089

EGD: esophagogastroduodenoscopy.

Table 2. Outcomes and clinical courses of the enrolled patients with caustic substance ingestion.

Variables	EGD grade		p-Value
	0/1/2a (%)	2b/3a/3b (%)
	(n = 193)	(n = 275)
Admission	75 (38.9)	232 (84.4)	<0.001
ICU admittance	9 (4.7)	50 (18.7)	<0.001
In-hospital mortality	0 (0)	17 (7.5)	0.016
Received surgical intervention	3 (1.6)	74 (26.9)	<0.001
Gastrointestinal complications
Perforation	0 (0)	13 (4.7)	0.002
Bleeding	21 (10.9)	49 (17.8)	0.038
Stricture	2 (1.0)	80 (29.1)	<0.001
Fistula	0 (0)	7 (2.5)	0.045
Systemic complications
Aspiration injury	17 (8.8)	51 (18.5)	0.003
Respiratory failure	8 (4.1)	34 (12.4)	0.002
Hepatic injury	4 (2.1)	22 (8.0)	0.006
Renal injury	6 (3.1)	23 (8.4)	0.020
DIC	0 (0)	10 (3.6)	0.007
Sepsis	0 (0)	14 (5.1)	0.001

DIC: disseminated intravascular coagulation; EGD: esophagogastroduodenoscopy; ICU: intensive care unit.

Figure 2. Caustic injury caused by substances with different doses and pH values.

Figure 3. Behavior-related etiology: strong acids/alkalis themselves, to some extent, limited the ingested dose.

Figure 4. Severity of caustic injury in the esophagus, stomach, and duodenum as assessed via esophagogastroduodenoscopy (EGD).

Table 3. Risk assessment of dose, pH, endoscopic findings, complications, and long-term survival outcomes.

	Incremental risk added by each factor
	Acids		Alkalis
Multi-faceted impacts	Strong (pH < 2)	Dose	Strong (pH > 12)	Dose
Urgent EGD grade
Esophagus ≥ 2b	4.4-fold	+1.4-fold/Δ100 mL^a	10.8-fold	n/a
Stomach ≥ 2b	10.9-fold	+1.3-fold/Δ100 mL^a	4.0-fold	n/a
Duodenum ≥ 2b	23.5-fold	+1.7-fold/Δ100 mL^a	n/a	n/a
Gastrointestinal complications
Perforation	n/a	+1.3-fold/Δ100 mL^a	10.7-fold	n/a
Bleeding	n/a	+1.2-fold/Δ100 mL^a	n/a	n/a
Stricture	20.9-fold	+1.3-fold/Δ100 mL^a	7.1-fold	n/a
Fistula	n/a	n/a	n/a	n/a
Systemic complications
Aspiration injury	n/a	+1.2-fold/Δ100 mL^a	n/a	n/a
Respiratory failure	n/a	n/a	n/a	n/a
Hepatic injury	0.3-fold^b	n/a	n/a	n/a
Renal injury	0.3-fold^b	n/a	n/a	n/a
DIC	n/a	n/a	12-fold	n/a
Sepsis	n/a	n/a	17.6-fold	n/a
Long-term overall survival outcomes	n/a	Dose-dependent	pH-dependent	n/a
		+1.3-fold/Δ100 mL^a	31.0-fold risk

The risk was assessed using either odds ratios (ORs) in multivariate logistic regression analyses or hazard ratios (HRs) in multivariate Cox proportional hazards models. For both acid and alkaline substances, “strong caustics (pH < 2 or pH > 12)” and “ingested dose” were used as covariates to obtain adjusted ORs and HRs. This table only presents the significantly increased/decreased risks with fold increases. Insignificant risks are indicated as “n/a”. DIC, disseminated intravascular coagulation; EGD, esophagogastroduodenoscopy; n/a, not statistically significant.

^a +X-fold/Δ100 mL denotes the risk association with each additional 100 mL of caustic substance ingestion.

^b No statistical difference in hepatic (p = 0.767) or renal (p = 0.343) complication risk was found in this study between acid and alkaline ingestion. However, in further analyses of acids, hepatic (OR = 0.258, p = 0.011) and renal (OR = 0.348, p = 0.027) complications were less frequently observed in cases of strong acid ingestion. Instead, the herbicides (pH 4.1–6.7 in this study) carried greater risks of hepatic and renal injuries.

Figure 5. Kaplan–Meier method: long-term survival outcomes were dose-dependent for acids and pH-dependent for alkalis.

Table 4. Multivariate Cox proportional hazards models of overall survival in patients with caustic substance ingestion.

Covariate	HR^a for death (95% CI)	p Value^a
Panel A. Acid substance ingestion (n = 300)
Dose (unit: 100 mL)	1.28 (1.10–1.49)	0.001
Substance pH value		0.566
Strong acids (pH < 2)	n/a (0.30–1.92)
Weak acids (pH ≥ 2)	reference
Panel B. Alkaline substance ingestion (n = 167)
Dose (unit: 100 mL)	n/a (0.86–2.86)	0.141
Substance pH value		0.013
Strong alkalis (pH > 12)	30.99 (2.07–463.30)
Weak alkalis (pH ≤ 12)	reference

Among the total 468 patients, one ingested neutral (neither acidic nor alkaline) laundry detergent (labeled as pH = 7.0 on the container), and thus, was excluded from survival analyses. CI, confidence interval; HR, hazard ratio.

^a HRs were calculated using multivariate Cox proportional hazards models. This table only presents the HRs significant at p < 0.05. Insignificant data are presented as “n/a (95% CI)”.