Death from caustic ingestion:A case report

Rationale:Acute caustic ingestion from suicidal intent is not usual in emergency departments in developed countries.One of the substances commonly ingested by suicidal patients,phosphoric acid,tends to cause multi-system derangements.Patient’s Concern:A 41-year-old male patient presented with complaints of throat discomfort,severe generalized abdominal pain,and multiple episodes of hematemesis after ingesting a restroom cleaning solution.Diagnosis:Poisoning by acute caustic ingestion(containing<30%phosphoric acid and<4%ethylene glycol).Interventions:The patient was administered 50 mL of 8.4%sodium bicarbonate solution followed by an isotonic sodium bicarbonate solution running at 500 mL/h,a hyperkalemia kit,ceftriaxone,metronidazole,omeprazole,and atropine.The patient then underwent urgent hemodialysis.Outcomes:The patient suffered gastrointestinal bleeding as a result of local caustic injury.In addition,his course of illness was complicated by severe acidemia from high anion gap metabolic acidosis and deranged electrolytes(hyperphosphatemia,hyperkalemia,and hypocalcemia).He developed multi-organ failure and eventually demised.Lessons:The clinician needs to be mindful of the multi-system complications arising from such a caustic ingestion.These patients need to be monitored closely for deterioration,and have prompt management of the various arising complications,to reduce the high morbidity and mortality associated with this condition.

Accidental Ingestion of Nitric Acid in an Agricultural Company: A Case Study and Literature Review

Introduction: Though common in society, caustic accidental ingestion is rare in the agricultural industry. This study describes a case of ingestion of nitric acid used as an agricultural fertilizer by an ordinary worker at the Société de Cultures Légumières. Clinical Case: This is a 33-year-old unschooled woman who ingested a sip of nitric acid from an abandoned labelled acid canister near a farming plot of land. She showed a burn of the oral cavity with a bleeding tablecloth and an intense retrosternal pain. The duodenal oesophagus fibroscopy screening that was carried out 18 hours after the accident, revealed an esophagitis class 2b. The tests revealed no anomalies. Fifteen (15) days after the accident, the FOGD was normal. Following an 8-month-follow up, no signs of stenosis or degeneration were noted. Conclusion: The accidental ingestion of nitric acid is rare in adult. Its treatment is mainly symptomatic and aims at preserving vital functions without directly fighting the ingested substance off. The right actions must be integrated into the 15-minute Health and Safety awarenesssessions for optimum pre-hospital management. The hospital evaluation is mandatory and is carried out thanks to the digestive endoscopy, which is still relevant in this indication, but is completed by the thoraco-abdominal CT. The latter is very sensitive the transmural necrosis diagnosis.

Endoscopic Aspects of Caustic Injuries of the Upper Gastrointestinal Tract in Parakou, Benin Republic: A Multicenter Study

Objective: Caustic ingestion is a medico-surgical emergency. The objective of this study is to describe endoscopic lesions of the upper gastrointestinal tract secondary to caustic ingestion in Parakou, Benin Republic. Patients and Methods: This was a retrospective and descriptive cross-sectional study. The study was multicenter in the gastrointestinal endoscopy units of the Teaching Hospital Center of Borgou-Alibori and the Military Teaching Hospital of Parakou. It covered the period from July 2015 to October 2021. This included any patient who ingested a caustic substance and performed a gastroscopy in one of the two endoscopy units. The variables studied were: socio-demographic data, the nature of the caustic substance ingested, the time between the caustic ingestion and the performance of gastroscopy and injuries of the upper gastrointestinal tract. Results: Out of the 24 patients included, 19 were men, i.e. a sex ratio of 3.8. Their average age was 25.54 ± 12.04 years with extremes of 6 and 50 years. Five subjects (20.83%) were under the age of 18 and the ingestion was accidental in them. Among the 19 patients aged at least 18 years, caustic ingestion was voluntary in 14 (73.68%). The caustic substance ingested was either a base (sodium hydroxide or caustic soda) or an acid (sulfuric acid) in 14 cases (58.33%) and 10 cases (41.67%), respectively. The time between the caustic ingestion and the performance of gastroscopy varied from 1 to 1095 days. The endoscopic lesions objectified were: stenosis (37.5%), ulcerations (29.17%), necrosis (20.83%), or erythema (12.25%). Conclusion: In Parakou, caustic ingestion, usually bases, is often voluntary in adult men. Endoscopic lesions were often ulcerative but sometimes necrotic.

Changing trends in the minimally invasive surgery for corrosive esophagogastric stricture

Esophagogastric stricture is the troublesome long-term complication of corrosive ingestion with a significant adverse impact on the quality of life.Surgery remains the mainstay of therapy in patients where endoscopic treatment is not feasible or fails to dilate the stricture.Conventional surgical management of esophageal stricture is open esophageal bypass using gastric or colon conduit.Colon is the commonly used esophageal substitute,particularly in those with high pharyngoesophageal strictures and in patients with accompanying gastric strictures.Traditionally colon bypass is performed using an open technique that requires a long midline incision from the xiphisternum to the suprapubic area,with adverse cosmetic outcomes and long-term complications like an incisional hernia.As most of the affected patients are in the second or third decade of life minimally invasive approach is an attractive proposition.However,minimally invasive surgery for corrosive esophagogastric stricture is slow to evolve due to the complex nature of the surgical procedure.With advancements in laparoscopic skills and instrumentation,the feasibility and safety of minimally invasive surgery in corrosive esophagogastric stricture have been documented.Initial series have mainly used a laparoscopic-assisted approach,whereas more recent studies have shown the safety of a total laparoscopic approach.The changing trend from laparoscopic assisted procedure to a totally minimally invasive technique for corrosive esophagogastric stricture should be carefully disseminated to preclude adverse longterm outcomes.Also,well-designed trials with long-term follow-ups are required to document the superiority of minimally invasive surgery for corrosive esophagogastric stricture.The present review focuses on the challenges and changing trends in the minimally invasive treatment of corrosive esophagogastric stricture.

Accidental ingestion of foreign bodies/harmful materials in children from Bahrain:A retrospective cohort study

BACKGROUND Children like to discover their environment by putting substances in their mouths.This behavior puts them at risk of accidentally ingesting foreign bodies(FBs)or harmful materials,which can cause serious morbidities.AIM To study the clinical characteristics,diagnosis,complications,management,and outcomes of accidental ingestion of FBs,caustics,and medications in children.METHODS We conducted a retrospective cohort study of all children admitted for accidental ingestion to the Department of Pediatrics,Salmaniya Medical Complex,Bahrain,between 2011 and 2021.Demographic data,type of FB/harmful material ingested,and investigations used for diagnosis and management were recorded.The patients were divided into three groups based on the type of ingested material(FBs,caustics,and medications).The three groups were compared based on patient demographics,socioeconomic status(SES),symptoms,ingestion scenario,endoscopic and surgical complications,management,and outcomes.The FB anatomical location was categorized as the esophagus,stomach,and bowel and compared with respect to symptoms.The Fisher’s exact,Pearson’s χ^(2),Mann-Whitney U,and Kruskal-Wallis tests were used for comparison.RESULTS A total of 161 accidental ingestion episodes were documented in 153 children.Most children were boys(n=85,55.6%),with a median age of 2.8(interquartile range:1.8-4.4)years.Most participants ingested FBs(n=108,70.6%),31(20.3%)ingested caustics,and the remaining 14(9.2%)ingested medications.Patients with caustic ingestion were younger at the time of presentation(P<0.001)and were more symptomatic(n=26/31,89.7%)than those who ingested medications(n=8/14,57.1%)or FBs(n=52/108,48.6%)(P<0.001).The caustic group had more vomiting(P<0.001)and coughing(P=0.029)than the other groups.Most FB ingestions were asymptomatic(n=55/108,51.4%).In terms of FB location,most esophageal FBs were symptomatic(n=14/16,87.5%),whereas most gastric(n=34/56,60.7%)and intestinal FBs(n=19/32,59.4%)were asymptomatic(P=0.002).Battery ingestion was the most common(n=49,32%).Unsafe toys were the main source of batteries(n=22/43,51.2%).Most episodes occurred while playing(n=49/131,37.4%)or when they were unwitnessed(n=78,57.4%).FBs were ingested more while playing(P<0.001),caustic ingestion was mainly due to unsafe storage(P<0.001),and medication ingestion was mostly due to a missing object(P<0.001).Girls ingested more jewelry items than boys(P=0.006).The stomach was the common location of FB lodgment,both radiologically(n=54/123,43.9%)and endoscopically(n=31/91,34%).Of 107/108(99.1%)patients with FB ingestion,spontaneous passage was noted in 54(35.5%),endoscopic removal in 46(30.3%),laparotomy in 5(3.3%)after magnet ingestion,and direct laryngoscopy in 2(1.3%).Pharmacological therapy was required for 105(70.9%)patients;79/105(75.2%)in the FB group,22/29(75.9%)in the caustic group,and 4/14(28.8%)in the medication group(P=0.001).Omeprazole was the commonly used(n=58;37.9%)and was used more in the caustic group(n=19/28,67.9%)than in the other groups(P=0.001).Endoscopic and surgical complications were detected in 39/148(26.4%)patients.The caustic group had more complications than the other groups(P=0.036).Gastrointestinal perforation developed in the FB group only(n=5,3.4%)and was more with magnet ingestion(n=4)than with other FBs(P<0.001).In patients with FB ingestion,patients aged<1 year(P=0.042),those with middle or low SES(P=0.028),and those with more symptoms at presentation(P=0.027)had more complications.Patients with complications had longer hospital stays(P<0.001)than those without.CONCLUSION Accidental ingestion in children is a serious condition.Symptomatic infants from middle or low SES families have the highest morbidity.Prevention through parental education and government legislation is crucial.

Caustic injury of the upper gastrointestinal tract: A comprehensive review

Prevention has a paramount role in reducing the incidence of corrosive ingestion especially in children, yet this goal is far from being reached in developing countries, where such injuries are largely unreported and their true prevalence simply cannot be extrapolated from random articles or personal experience. The specific pathophysiologic mechanisms are becoming better understood and may have a role in the future management and prevention of long-term consequences, such as esophageal strictures. Whereas the mainstay of diagnosis is considered upper gastrointestinal endoscopy, computed tomography and ultrasound are gaining a more significant role, especially in addressing the need for emergency surgery, whose morbidity and mortality remains high even in the best hands. The need to perform emergency surgery has a persistent long-term negative impact both on survival and functional outcome. Medical or endoscopic prevention of stricture is debatable, yet esophageal stents, absorbable or not, show promising data. Dilatation is the first therapeutic option for strictures and bougies should be considered especially for long, multiple and tortuous narrowing. It is crucial to avoid malnutrition, especially in developingcountries where management strategies are influenced by malnutrition and poor clinical conditions. Late reconstructive surgery, mainly using colon transposition, offers the best results in referral centers, either in children or adults, but such a difficult surgical procedure is often unavailable in developing countries. Possible late development of esophageal cancer, though probably overemphasized, entails careful and long-term endoscopic screening.

Therapeutic upper gastrointestinal tract endoscopy in Paediatric Gastroenterology

Since the first report of use of endoscopy in children in the 1970 s, there has seen an exponential growthin published experience and innovation in the field. In this review article we focus on modern age therapeutic endoscopy practice, explaining use of traditional as well as new and innovative techniques, for diagnosis and treatment of diseases in the paediatric upper gastrointestinal tract.

Endoscopic management of esophageal stenosis in children:New and traditional treatments

Post-esophageal atresia anastomotic strictures and postcorrosive esophagitis are the most frequent types of cicatricial esophageal stricture. Congenital esophageal stenosis has been reported to be a rare but typical disease in children; other pediatric conditions are peptic, eosinophilic esophagitis and dystrophic recessive epidermolysis bullosa strictures. The conservative treatment of esophageal stenosis and strictures(ES) rather than surgery is a well-known strategy for children. Before planning esophageal dilation, the esophageal morphology should be assessed in detail for its length, aspect, number and level, and different conservative strategies should be chosen accordingly. Endoscopic dilators and techniques that involve different adjuvant treatment strategies have been reported and depend on the stricture's etiology, the availability of different tools and the operator's experience and preferences. Balloon and semirigid dilators are the most frequently used tools. No high-quality studies have reported on the differences in the efficacies and rates of complications associated with these two types of dilators. There is no consensus in the literature regarding the frequency of dilations or the diameter that should be achieved. The use of adjuvant treatments has been reported in cases of recalcitrant stenosis or strictures with evidence of dysphagic symptoms. Corticosteroids(either systemically or locally injected), the local application of mitomycin C, diathermy and laser ES sectioning have been reported. Some authors have suggested that stenting can reduce both the number of dilations and the treatment length. In many cases, this strategy is effective when either metallic or plastic stents are utilized. Treatment complications, such esophageal perforations, can be conservatively managed, considering surgery only in cases with severe pleural cavity involvement. In cases of stricture relapse,even if such relapses occur following the execution of well-conducted conservative strategies, surgical stricture resection and anastomosis or esophageal substitution are the only remaining options.

CAUSTIC DECOMPOSITION OF SCHEELITE AND SCHEELITE－WOLFRAMITE CONCENTRATES THROUGH MECHANICAL ACTIVATION

Based on physicochemical study of the reaction between scheelite and NaOH, a new decomposition process for scheelite and scheelitewolframite concentrate, i. e., mechenically activating caustic decomposition has been developed, and it has been successfu

Dynamic caustics test of blast load impact on neighboring different cross-section roadways

Using digital laser dynamic caustics experimental system and conducting simulation experiment researched the influence rule of blasting excavation of a new roadway on neighboring existed different cross-section roadways. The experimental results show that the influence of blast load on adjacent roadway has a good relationship with the cross-section of roadway. The expansion distance of precrack existed in circular, arch-wall, rectangular roadway is respectively 1.76, 1.61 and 0 cm under blast load.At the same time, the direct-blast side of rectangular roadway has more obvious damage compared with circular and arch-wall roadway. It explains that plane reflects more stress wave than arc, so that it exerts more tensile failure in the direct-blast side, which leads to less stress wave diffracting to the precrack in the back-blast side. When the precrack extends, higher value dynamic stress intensity factor in circular roadway works longer than that of arch-wall roadway. Indirectly, it explains that plane's weakening function on stress wave is significantly stronger than arc. Stress wave brings about self-evident influence on the upper and bottom endpoints of the rectangular roadway, and it respectively extends 1.03, 2.06 cm along the line link direction of the center of the blasthole and the upper and bottom endpoints on the right wall.

DETERMINATION OF THE DYNAMIC STRESS INTENSITY FACTORS,K_Ⅰ~d AND K_Ⅱ~d,FOR A MIXED-MODE PROPAGATING CRACK

In this paper,the dynamic propagation problem of a mixed-mode crack was studied by means of the experimental method of caustics.The initial curve and caustic equations were derived un- der the mixed-mode dynamic condition.A multi-point measurement method for determining the dy- namic stress intensity factors,K_Ⅰ~d and K_Ⅱ~d,and the position of the crack tip was developed.Several other methods were adopted to check this method,and showed that it has a good precision.Finally, the dynamic propagating process of a mixed-mode crack in a three-point bending beam specimen was investigated with our method.

INFLUENCE OF LOADING RATE ON DYNAMIC FRACTURE BEHAVIOR OF FIBER-REINFORCED COMPOSITES

The effect of loading rate on the dynamic fracture properties and the failure mechanisms of glass fiber-reinforced composite materials under mode I fracture is studied. Dynamic reflective caustic experiments are carried out for two loading rates. By measuring the characteristic dimensions of the shadow spots during the caustic experiments, the dynamic SIFs are calculated for different loading rates. The experimental results indicate that the dynamic fracture toughness Kid increases remarkably with increasing loading rate, and the crack grows faster under the high-velocity impact. Moreover, by examining the crack growth routes and the fracture surfaces, it is shown that the loading rate also greatly affects the failure mechanisms at micro-scale.

Role of endoscopy in caustic injury of the esophagus

Caustic injury of the esophagus is a problematic condition challenging endoscopists worldwide. Althoughthe caustic agents and motives are different among countries and age groups, endoscopy still plays an invaluable role in diagnosis and treatment. Endoscopy can determine the severity of caustic ingestion which is of great importance in choosing appropriate treatment. However, some aspects of endoscopy in diagnosis of caustic injury remain controversial. Whether or not all patients need endoscopy, when to perform endoscopy and how to assess the severity are just some examples of these controversies. Due to lack of randomized controlled trials, many findings and suggestions are inconclusive. Computerized tomography scan of the chest and abdomen gains popularity in assessing the severity of caustic injury and avoiding unnecessary surgery. If esophageal stricture eventually develops, endoscopic dilatation is a mainstay. Maneuvers such as steroid injection and esophageal stent may be used in a refractory stricture. Nevertheless, some patients have to undergo surgery in spite of vigorous attempts with esophageal dilatation. To date, caustic injury remains a difficult situation. This article reviews all aspects of caustic injury of the esophagus focusing on endoscopic role. Pre-endoscopic management, endoscopy and its technique in acute and late phase of caustic injury including the endoscopic management of refractory stricture, and the treatment outcomes following each endoscopic intervention are thoroughly discussed. Finally, the role of endoscopy in the long term follow-up of patients with esophageal caustic injury is addressed.

A NEW TECHNOLOGY FOR PRODUCTION O F HIGH PURITY PARATUNGSTATE AMMONIUM FROM LOW GRADE TUNGSTEN CONCENTRATE

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A decomposing technique for scheelite concentrate and low-grade scheelite concentrate

The effect of different decomposition conditions on tungsten recovery forscheelite concentrate has been examined. The results show that tungsten recovery can be more than98% under decomposing conditions as follows: the amount of caustic soda is 2.2 and 3.2 times oftheoretical respectively, ratio of water and ore is 0.7-0.8, temperature is 160℃, and preservationtime is 2.0 h for scheelite concentrate (63.21 % WO_3) and low grade scheelite concentrate (55.17%WO_3).

Management of esophageal caustic injury

Ingestion of caustic substances and its long-term effect on the gastrointestinal system maintain its place as an important public health issue in spite of the multiple efforts to educate the public and contain its growing number. This is due to the ready availability of caustic agents and the loose regulatory control on its production. Substances with extremes of pH are very corrosive and can create severe injury in the upper gastrointestinal tract. The severity of injury depends on several aspects: Concentration of the substance, amount ingested, length of time of tissue contact, and p H of the agent. Solid materials easily adhere to the mouth and pharynx, causing greatest damage to these regions while liquids pass through the mouth and pharynx more quickly consequently producing its maximum damage in the esophagus and stomach. Esophagogastroduodenoscopy is therefore a highly recommended diagnostic tool in the evaluation of caustic injury. It is considered the cornerstone not only in the diagnosis but also in the prognostication and guide to management of caustic ingestions. The degree of esophageal injury at endoscopy is a predictor of systemic complication and death with a 9-fold increase in morbidity and mortality for every increased injury grade. Because of this high rate of complication, prompt evaluation cannot be overemphasized in order to halt development and prevent progression of complications.

RAMAN SPECTRA OF SODIUM ALUMINATE SOLUTIONS WITH HIGH-CAUSTIC RATIO AND HIGH CONCENTRATION

The constitution of high-caustic ratio and highly concentrated sodium aluminate solutions has been investigated by Raman spectra method.By comparison with the Raman spectra of crystalline solids of Ca_3[Al(OH)_6]_2 and Ba_2[Al_2(OH)_(10)],it can be concluded that AI(OH)_6^(3-)ion and perhaps its polymers may be formed in these solutions.

UV-catalytic treatment of spent caustic from ethene plant with hydrogen peroxide and ozone oxidation

The performance of UV/H 2O 2, UV/O 3 and UV/H 2O 2/O 3 oxidation systems for treating spent caustic from an ethylene plant was investigated. In UV/H 2O 2 system, with the increase of H 2O 2 dosage, removal efficiencies of COD and the ratio of biochemical oxygen demand(BOD) to chemical oxygen demand(COD) of the effluent were increased and a better performance was obtained than the H 2O 2 system alone. In UV/H 2O 2 system, removal efficiency of COD reach 68% under the optimum condition, and BOD/COD ratio was significantly increased from 0 22 to 0 52. In UV/O 3 system, with the increase of O 3 dosage, removal efficiency of COD and BOD/COD ratio were increased, and a better performance was obtained than the O 3 system alone. Under the optimum condition, removal efficiency of COD was 54%, and BOD/COD ratio was significantly increased from 0 22 to 0 48. In UV/H 2O 2/O 3 system, COD removal efficiency was found to be 22.0% higher than UV/O 3 system.

Recycling water glass from wet reclamation sewage of waste sodium silicate-bonded sand

Wet reclamation of waste sodium silicate-bonded sand produces much alkaline sewage and causes pollution. Recycling water glass from wet reclamation sewage of the waste sodium silicate-bonded sand can solve pollution issues and generate economic benefits. In this work, the wet reclamation sewage was filtered, and the filtrate was causticized with a quicklime powder to produce a lye. The effects of causticization temperature, causticization time, and the amount of quicklime powder on the causticization rate were studied. The lye was used to dissolve the silica in the filtration residue to prepare a sodium silicate solution. The effects of the mass of filtration residue, dissolution temperature, and dissolution time on sodium silicate modulus were studied. Finally, the recycled water glass was obtained by concentrating the sodium silicate solution, and the bonding strength of the recycled water glass was tested. The results showed that the causticization rate could be improved by increasing the amount of quicklime powder, causticization temperature, and causticization time, and the highest causticization rate was above 92%. Amorphous silica in the filtration residue dissolved in the lye. Increasing the amount of the filtration residue, dissolution temperature, and dissolution time could improve the sodium silicate modulus. The bonding strength of the recycled water glass was close to that of commercial water glass. The recycled water glass could be used as a substitute for the commercial water glass.

Upgrading Paper-grade Softwood Kraft Pulp to Dissolving Pulp by Cold Caustic Extraction

Cold caustic extraction has potential applications in the production of dissolving-grade pulps due to its ability to selectively remove hemicellulose from lignocellulosic materials. In this study,we demonstrate the conversion of paper-grade kraft pulp into dissolving pulp by a single-stage cold caustic extraction. Under the extraction conditions of 12 wt% NaOH lye,11% pulp consistency,a temperature of 35℃,and 2 h,a paper-grade softwood kraft pulp was purified to high-grade dissolving pulp with 97. 1% α-cellulose content,1. 2% pentosane content,and narrowed molecular weight distribution. The resulting extraction filtrate was concentrated by nano-filtration to obtain the hemicellulose content of 59. 0 g / L,while the permeate was a clear Na OH solution with 10. 9 wt% concentration. A process configuration was also proposed,integrating this cold caustic extraction process with existing pulp and paper production and multi-purpose utilization of the extraction filtrate.