Predicting full-thickness necrosis in adult acute corrosive ingestion injuries in a sub-Saharan African setting

Table 1 Classification systems for endoscopic and computed tomography grading of acute corrosive injuries

Modified Zargar endoscopic grading[1]
Grade 0	Normal
Grade I	Oedema and hyperaemia of mucosa
Grade IIA	Superficial localised ulcerations, friability and blisters
Grade IIB	Circumferential and deep ulcerations
Grade IIIA	Multiple and deep ulcerations and small, scattered areas of necrosis
Grade IIIB	Extensive necrosis
Grade IV	Perforation
CT grading[2]
Grade 1	Normal appearance
Grade 2	Wall and soft tissue oedema, increased wall enhancement
Grade 3	Transmural necrosis with absent wall enhancement (with or without perforation)

Table 2 Baseline demographics and details of the corrosive ingestion incident

Baseline demographics (n = 100)	n	%
Gender
Female	35	35.0
Male	65	65.0
Comorbidities
No	67	67.0
Yes	33	33.0
Specified comorbidities
Known psychiatric history	15	15.0
HIV positive	12	12.0
Hypertension	2	2.0
Obesity	3	3.0
Diabetes mellitus	1	1.0
Other comorbidity	7	7.0
Substance use
No	59	59.0
Yes	41	41.0
Substance use specified
Smoking	31	31.0
Alcohol - regular use	21	21.0
Marijuana	10	10.0
Methamphetamine	8	8.0
Methaqualone	7	7.0
Opioids	1	1.0
Prior corrosive ingestion/suicide attempt
Yes	11	11.0
No	89	89.0
Corrosive ingestion incident (n = 100)
Intentional/accidental
Intentional (suicidal)	73	73.0
Accidental	20	20.0
Forced ingestion (assault)	5	5.0
Unknown	2	2.0
Substance ingested
Acid	32	32.0
Sulphuric acid	22
Hydrochloric acid	3
Other acid	7
Alkali	58	58.0
Sodium hypochlorite (bleach)	30
Sodium hydroxide	27
Other alkali	3
Other corrosive substance	10	10.0
Unknown corrosive substance	5	5.0

HIV: Human immunodeficiency virus.

Table 3 Imaging and endoscopy investigations performed on admission

Imaging/endoscopy during acute admission (n = 100)	n	%	n	%	n	%
Endoscopy	95	95.0
Chest X-ray	82	82.0
Lateral neck X-ray	31	31.0
CT	17	17.0
Contrast swallow	1	1.0
None	1	1.0
Endoscopy findings (n = 95)	n	%	n	%	n	%
	Oesophagus		Stomach		Duodenum
Not entered	1	1.1	3	3.2	32	33.7
Zargar 0	23	24.2	14	14.7	42	44.2
Zargar I	11	11.6	25	26.3	9	9.5
Zargar IIA	20	21.1	14	14.7	7	7.4
Zargar IIB	26	27.4	8	8.4	1	1.1
Zargar IIIA	6	6.3	16	16.8	1	1.1
Zargar IIIB	8	8.4	14	14.7	3	3.2
Zargar IV	0	0.0	1	1.1	0	0.0
CT findings (n = 17)	n	%	n	%
	Oesophagus		Stomach
Grade 1 - normal	2	11.8	5	29.4
Grade 2 - oedematous only	11	64.7	8	47.1
Grade 3 - lack of contrast enhancement
Without perforation	3	17.6	2	11.8
With perforation	1	5.9	2	11.8

CT: Computed tomography.

Table 4 Overview of acute management

Management
Median (IQR) time from ingestion to first healthcare assessment	6 (2-13) hours
Emergency resuscitation	n	%
Required emergency resuscitation	23	23.0
Specified
Endotracheal intubation	19	19.0
Chest compressions	1	1.0
Inotropes	3	3.0
Other1	2	2.0
Other management initiated in the emergency department
Proton pump inhibitor therapy	35	35.0
Prophylactic antibiotics	7	7.0
Therapeutic antibiotics	4	4.0
Nasogastric tube insertion (for drainage, not feeding)	4	4.0
Activated charcoal administration	4	4.0
Steroids	1	1.0
Neutralizing agent	0	0.0
Surgery
Required acute surgery	20	20.0
Decision for needing surgery (n = 20)
Based on endoscopy findings	13	65.0
Based on CT findings	5	25.0
Based on clinical findings only	2	10.0
Type of surgery (n = 20)
Emergency resection performed	11	55.0
Oesophagectomy only	1
Oesophagogastrectomy	5
Gastrectomy only	5
Extended resections2	2
Exploration only - decision for palliation	6	30.0
Feeding jejunostomy (only)	1	5.0
Gastrojejunostomy & gastrostomy	1	5.0
Negative laparotomy	1	5.0

¹Other emergency resuscitation: Atropine with methylene blue administration for bradycardia & methaemoglobinaemia and recurrent emergency potassium shifting for refractory hyperkalaemia.

²Extended resections: Oesophagogastrectomy/total gastrectomy with additional pancreas-preserving duodenectomy and proximal jejunal resection in two patients. CT: Computed tomography.

Table 5 Outcomes for 30-days post corrosive ingestion. Acute admission outcomes

Outcomes (n = 100)	n	%
30-day mortality	14	14.0
30-day morbidity	27	27.0
Required ICU management	26	26.0
Median (IQR) ICU stay	2.5 (2-3.25) days
Median (IQR) length of hospital stay	6 (2-15.5) days
Acute morbidities specified (n = 39)
Pneumonia (nosocomial)	7	17.9
Acute kidney injury	5	12.8
Cardiac arrest (unexpected)	4	10.3
Refeeding syndrome	3	7.7
Systemic sepsis	2	5.1
Unplanned extubation	2	5.1
Surgical site infection	2	5.1
Other	14	35.9

ICU: Intensive care unit.

Table 6 Multivariate analysis of numerous admission variables in predicting full thickness necrosis and short-term mortality, n (%)

Variables			Predicting full thickness necrosis						Predicting acute mortality
		Total, n	No FT necrosis		FT necrosis		P value	ROC AUC	No mortality		Mortality		P value	ROC AUC
Gender	Female	35	31	88.6	4	11.4	0.279		28	80.0	7	20.0	0.207
	Male	65	52	80	13	20			58	89.2	7	10.8
At least one comorbidity	No	67	58	86.6	9	13.4	0.178		56	83.6	11	16.4	0.323
	Yes	33	25	75.8	8	24.2			30	90.9	3	9.1
Known psychiatric history	No	85	71	83.5	14	16.5	0.739		72	84.7	13	15.3	0.377
	Yes	15	12	80	3	20			14	93.3	1	6.7
Known HIV positive	No	88	75	85.2	13	14.8	0.11		74	84.1	14	15.9	0.138
	Yes	12	8	66.7	4	33.3			12	100.0	0	0.0
Prior corrosive/suicide attempt	No	89	75	84.3	14	15.7	0.339		77	86.5	12	13.5	0.673
	Yes	11	8	72.7	3	27.3			9	81.8	2	18.2
Needing endotracheal intubation	No	82	71	86.6	11	13.4	0.043	0.604	69	84.1	13	15.9	0.257
	Yes	18	12	66.7	6	33.3			17	94.4	1	5.6
Needing chest compressions	No	99	83	83.8	16	16.2	0.027	0.529	85	85.9	14	14.1	0.687
	Yes	1	0	0	1	100			1	100.0	0	0.0
Needing inotropes/vasopressors	No	97	81	83.5	16	16.5	0.447		83	85.6	14	14.4	0.480
	Yes	3	2	66.7	1	33.3			3	100.0	0	0.0
≥ Zargar IIIB endoscopic findings	No	79	75	94.9	4	5.1	< 0.001	0.85	74	93.7	5	6.3	< 0.001	0.759
	Yes	16	4	25	12	75			8	50.0	8	50.0
Grade 3 CT Findings	No	12	10	83.3	2	16.7	0.016	0.788	11	91.7	1	8.3	0.026	0.798
	Yes	5	1	20	4	80			2	40.0	3	60.0
Age (years)		100	31 (24-38)		39 (30-50)		0.015	0.687	32 (24-40)		31 (25-40)		0.917
Systolic BP (mmHg)		48	134 (114-143)		129 (113-149)		0.926		130 (113-144)		134 (120-137)		0.919
Diastolic BP (mmHg)		48	80 (73-90)		83 (75-97)		0.309		82 (73-90)		79 (64-91)		0.520
Heart rate (beats per minute)		48	94 (79-109)		86 (72-105)		0.405		93 (76-110)		94 (82-107)		0.965
Urea (mmol/L)		79	4.6 (3.3-5.9)		5.1 (2.7-7.1)		0.686		4.7 (3.2-6.5)		3.9 (3.4-5.4)		0.432
Creatinine (umol/L)		88	70 (57-81)		84 (68-102)		0.038	0.666	72 (58-85)		72 (66-84)		0.892
WCC (× 109/L)		85	14.07 (9.58-18.31)		13.80 (9.76-19.16)		0.695		13.79 (9.59-18.31)		15.75 (10.63-20.50)		0.605
Platelets (× 109/L)		81	253 (210-326)		206 (171-266)		0.045	0.666	245 (194-308)		263 (232-375)		0.142
Calcium (mmol/L)		12	2.21 (2.00-2.35)		1.99 (199-1.99)		0.31		2.15 (1.99-2.35)		2.21 (2.21-2.21)		0.885
pH		41	7.37 (7.31-7.42)		7.13 (7.07-7.35)		0.003	0.823	7.35 (7.17-7.40)		7.36 (7.27-7.43)		0.593
Base excess (mEq/L)		40	-0.50 (-5.50-2.10)		-14.20 (-17.00 to -4.60)		0.004	0.819	-3.2 (-12.1-0.65)		2.45 (-0.58-5.38)		0.020	0.199
Lactate (mmol/L)		40	1.80 (1.20-3.30)		3.20 (2.60-4.45)		0.026	0.746	2.45 (1.20-3.55)		1.55 (1.18-3.48)		0.677
Ingestion to first assessment (hours)		94	6.0 (2.5-14.5)		4.0 (2.0-8.5)		0.209		6.0 (3.0-15.5)		3.0 (1.5-6.5)		0.052

All numerical values expressed as median (inter-quartile range).

FT necrosis: Full thickness necrosis; ROC AUC: Receiver operator characteristic curve area under the curve; HIV: Human immunodefiency virus; CT: Computed tomography; BP: Blood pressure; WCC: White cell count.

Table 7 Admission endoscopy, computed tomography and blood gas performance in predicting full thickness necrosis

	Total	FT necrosis	Not FT necrosis	Sensitivity, %	Specificity, %	PPV, %	NPV, %	P value	ROC AUC
Endoscopy performance (n = 95)
Zargar IIIB	16	12	4	75.0	94.9	75.0	94.5	< 0.001	0.850
CT performance (n = 17)
CT grade 3	5	4	1	66.7	90.9	80.0	83.3	0.026	0.788
Blood gas performance (n = 40)
pH < 7.35	20	7	13	77.8	58.1	35.0	90.0	0.062	0.679
BE < -2 mEq/L	18	7	11	77.8	64.5	38.9	90.9	0.027	0.711
Lactate > 2.0 mmol/L	21	8	13	88.9	58.1	38.1	94.7	0.014	0.735
Blood gas performance (Patients with concomitant toxin ingestion removed) (n = 35)
pH < 7.35	19	7	12	77.8	58.1	35.0	100.0	0.007	0.786
BE < -2 mEq/L	17	7	10	77.8	58.1	35.0	100.0	0.003	0.821
Lactate > 2.0 mmol/L	18	6	12	77.8	58.1	35.0	94.1	0.046	0.714

FT necrosis: Full thickness necrosis; PPV: Positive predictive value; NPV: Negative predictive value; ROC AUC: Receiver operator characteristic area under the curve; CT: Computed tomography.