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PubMed2005

Chest wall necrosis and death secondary to hydrochloric acid infusion for metabolic alkalosis.

Central line complications are common, and extravasation injuries related to infusion of caustic substances have been previously described. Although hydrochloric acid has been used for many years to treat metabolic alkalosis, there have been no reported fatal complications. We report the case of a 53-year-old female who received a fatal chemical burn due to extravasation from a subclavian central venous catheter of hydrochloric acid infused to correct severe metabolic alkalosis. This case illustrates the hazards of the infusion of caustic substances through central lines and underscores the importance of constant vigilance regarding line positioning and changes to the surrounding tissues when infusing these substances.

Alkalosis↗
PubMed2006

Computation of uniform wave forms using complex rays.

Complex rays and polynomial phase functions are used to numerically solve the Helmholtz equation in a realistic two-dimensional smoothly varying heterogeneous velocity model with multiple adjacent cusp caustics. Together these two methods allow the determination of global uniformly asymptotic solutions in the presence of arbitrarily many caustics. Two algorithms are introduced to this end: a two-point ray tracing algorithm for complex rays and a perturbation method for constructing polynomial phase functions. Model representation in complex space is performed via discrete cosine transform analysis. Geometrical and uniformly asymptotic solutions are computed for a linear layer test model as well as a velocity model from Yucca Mountain.

Journal Article↗
PubMed1997

Surgical results of 23 patients with tracheobronchial injuries.

The objective of this study was to evaluate the surgical results of tracheobronchial injuries. Between July 1988 and March 1996, tracheobronchial surgery was performed on 23 injured patients. According to the aetiology, the injuries were categorized as blunt injury (n = 13), cutting or penetrating injury (n = 5), and corrosive injury (n = 5). Blunt injuries included three complete laryngotracheal disruptions, one tracheal laceration, and eight bronchial ruptures. Cutting or penetration injuries included four laryngotracheal ruptures and one tracheal cutting wound. Corrosive injuries included one tracheal necrosis, one tracheal stenosis and three esophagorespiratory fistulae. Operative procedures that were performed on the tracheobronchus included tracheoplasty (n = 12), bronchoplasty (n = 7), sleeve resection of the trachea (n = 2) and bronchus (n = 2). Two hospital deaths were encountered, with a mortality rate of 8.7%. One patient with caustic injury died of bronchopleural fistula and empyema. The other patient died with multiple injuries from multiple organ failure which was unrelated to the bronchoplasty. One postoperative complication was restenosis of the trachea in a caustic injured patient, which was treated by a T-tube insertion. In conclusion, tracheobronchoplasty is an effective life-saving emergency procedure for the patients with tracheobronchial injuries.

Adult↗
PubMed1999

Endoscopic dilation of benign esophageal strictures: report on 1043 procedures.

OBJECTIVE: Endoscopic dilation is considered the best treatment for most cases of benign esophageal stricture, although the best dilation technique and the kind of stricture is the most amenable to treatment is still controversial. We report on our experience on a large series of patients treated by dilation without the aid of fluoroscopy and compare the results of this therapy among patients with strictures from different causes. METHODS: Between 1992 and 1997, we performed 1043 dilation sessions on 153 patients. Treatment was considered adequate if the esophageal lumen could be dilated up to the size of a 42F catheter. If the stricture recurred after initial successful treatment, the stricture was dilated again up to a 42F catheter. RESULTS: One hundred forty patients (96 men, 44 women; mean age, 54.1 yr) were followed-up for a mean of 20.5 months (4 to 62 months). Stricture's etiology was postsurgical in 80 patients, peptic in 37, caustic in 12, and from other causes in 11 patients. Adequate dilation was achieved in 93.5% of the patients (131 of 140). Patients with peptic strictures needed a median of three sessions to be adequately dilated during follow-up in comparison to five sessions among patients with postsurgical or caustic strictures (p = 0.07). There were four perforations, with one death (2.8% and 0.7% per patient and 0.4% and 0.1% per session, respectively). CONCLUSIONS: Endoscopic dilation without the aid of fluoroscopy is safe and effective in relieving dysphagia caused by benign strictures of different causes, although repeated sessions are necessary because of stricture recurrence.

Adolescent↗
PubMed1993

Internal stress wave measurements in solids subjected to lithotripter pulses.

Semiconductor strain gauges were used to measure the internal strain along the axes of spherical and disk plaster specimens when subjected to lithotripter shock pulses. The pulses were produced by one of two lithotripters. The first source generates spherically diverging shock waves of peak pressure approximately 1 MPa at the surface of the specimen. For this source, the incident and first reflected pressure (P) waves in both sphere and disk specimens were identified. In addition, waves reflected by the disk circumference were found to contribute significantly to the strain fields along the disk axis. Experimental results compared favorably to a ray theory analysis of a spherically diverging shock wave striking either concretion. For the sphere, pressure contours for the incident P wave and caustic lines were determined theoretically for an incident spherical shock wave. These caustic lines indicate the location of the highest stresses within the sphere and therefore the areas where damage may occur. Results were also presented for a second source that uses an ellipsoidal reflector to generate a 30-MPa focused shock wave, more closely approximating the wave fields of a clinical extracorporeal lithotripter.

Acoustics↗
PubMed1997

Finite difference predictions of P-SV wave propagation inside submerged solids. I. Liquid-solid interface conditions.

A finite difference scheme has been developed to analyze internal strains in submerged elastic solids of irregular geometry subjected to ultrasonic wave sources that simulate a clinical lithotripter. In part I of this paper, the finite difference formulation that accounts for arbitrary liquid-solid interfaces is presented and sample numerical results are discussed. Two different methods for discretizing the liquid-solid interface conditions are developed. The first treats the interface conditions explicitly. The second integrates the heterogeneous wave equations across the interface using the divergence theorem. Both schemes account for varying grid sizes and give similar results for a test problem consisting of a radially diverging source incident on the rectangular solid. The time sequence obtained numerically for strain at the center of a rectangular solid matches well with the experimental results [S. M. Gracewski et al., J. Acoust. Soc. Am. 94, 652-661 (1993)] in terms of the arrival times and the relative amplitudes of the peaks. In addition, strain contours are plotted to visualize the propagation of P (longitudinal) and S (shear vertical) waves inside a circular solid. The reflection from the concave back surface of the circular solid has a focusing effect with the subsequent formation of focal zones, known as caustics, where peak strains occur. In part II of this paper, the finite difference scheme is used to study the effects of geometry changes on the internal stresses and caustics predicted in model stones subjected to lithotripter pulses.

Acoustics↗
PubMed2006

Occupational risk factors for nasopharyngeal cancer among female textile workers in Shanghai, China.

AIMS: To investigate whether occupational exposure to dusts and chemicals in the Chinese textile industry are associated with risk of nasopharyngeal cancer. METHODS: Sixty seven nasopharyngeal carcinoma (NPC) cases identified during 1989-98 and a random sample (n = 3188) of women were included in a case cohort study nested in a cohort of 267,400 women textile workers in Shanghai, China. A complete occupational history of work in the textile industry was obtained for each woman. A job exposure matrix developed by experienced industrial hygienists was used to assess exposures to specific dusts and chemicals. RESULTS: Risk of NPC is associated with cumulative exposure to cotton dust. The hazard ratio for women cumulatively exposed to >143.4 mg/m3 x years of cotton dust was 3.6 (95% CI 1.8 to 7.2) compared with unexposed women. Trends of increasing risk were also found with increasing duration of exposure to acids and caustics (p = 0.05), and with years worked in dyeing processes (p = 0.06). Women who worked at least 10 years in dyeing processes had a 3.6-fold excess risk of NPC (95% CI 1.0 to 12.1). CONCLUSIONS: Occupational exposure to cotton dust, acids, and caustics, and work in dyeing and printing jobs in the textile industry may have increased risk of NPC in this cohort.

Adult↗
PubMedDate not supplied

Surgical management of strictures of the cervical esophagus.

Strictures of the esophagus are difficult and challenging problems. Whether a result of caustic ingestion, trauma, or surgery, or a congenital abnormality, the patient suffers a disruption of the fundamental act of swallowing. The seven cases of stricture of the cervical esophagus presented here were not alleviated by the usual methods of antegrade and retrograde dilation. Each patient underwent a two-stage reconstruction of the esophagus. The strictures in four patients were secondary to a caustic agent, two were congenital, and one was of unknown etiology. All patients no longer require dilation and are essentially cured. This procedure will add to the armamentarium of the surgeon who deals with "hopeless" strictures of the cervical esophagus and, in properly selected cases, should be successful.

Burns, Chemical↗
PubMedDate not supplied

Effects of N-acetylcysteine on experimentally induced esophageal lye injury.

The effects of N-acetylcysteine (NAC) in the treatment of caustic alkaline injury to the esophagus is examined. Caustic esophageal burns were produced in rats by irrigation with NaOH. Stricture formation was less frequent in animals concurrently treated with either steroids (48%) or NAC (48%) than in control animals that received only the alkaline injury (74%). In addition, the severity of stenosis was less in drug-treated rats. Thirty percent of strictures in control animals were severe (3 +) compared to 6% in the NAC group and 7% in the steroid group. Both NAC and steroids would seem to ameliorate the tissue reaction to chemical injury as well as temper the degree of stenosis formation. Possibility of synergistic effects warrants future investigation.

Acetylcysteine↗
PubMed2006

Testing a fast off-axis parabolic mirror by using tilted null screens.

We propose the design of tilted null screens for testing off-axis segments of conic surfaces. The tilt allows us to control the size of the screen and the sensitivity of the test. For positive tilt angles the sensitivity is increased while the size of the screen is reduced in the sagittal caustic region and vice versa in the tangential caustic region. Further analysis and preliminary experimental results are presented for a fast off-axis concave parabolic mirror with an elliptical aperture. An offset distance of X(C) = 25.4 mm yields radius of curvature at the vertex R = 20.4 mm; major axis of the mirror D(M) = 49.4 mm; and minor axis D(m) = 29.5 mm.

Journal Article↗
PubMed2000

Drug-induced oesophageal disorders: pathogenesis, incidence, prevention and management.

Drug-induced injury of the oesophagus is a common cause of oesophageal complaints. 'Pill-induced' oesophagitis is associated with the ingestion of certain drugs and accounts for many cases of erosive oesophagitis. To date, more than 70 drugs have been reported to induce oesophageal disorders. Antibacterials such as doxycycline, tetracycline and clindamycin are the offending agents in more than 50% of cases. Other commonly prescribed drugs that cause oesophageal injury include aspirin (acetylsalicylic acid), potassium chloride, ferrous sulfate, quinidine, alprenolol and various steroidal and nonsteroidal anti-inflammatory agents. However, many physicians and even more patients are not aware of this problem. Capsules or tablets are commonly delayed in their passage through the oesophagus. Highly caustic coatings, direct medication injury and poor oesophageal clearance of pills can lead to acute inflammation. Oesophageal damage occurs when the caustic contents of a drug remain in the oesophagus long enough to produce mucosal lesions. Taking medications at bedtime or without fluids is a common cause of oesophagitis. The possibility of drug-related damage should be suspected in all cases of oesophagitis, chest pain and dysphagia. History and gastrointestinal endoscopy will confirm the diagnosis. Treatment is supportive, although acid reduction is used frequently as an adjunct. This review reflects the current state of knowledge in this field.

Capsules↗
PubMed2006

Parameters governing permeate flux in an anaerobic membrane bioreactor treating low-strength municipal wastewaters: a literature review.

The objective of this review was to conduct a comprehensive literature survey to identify the parameters that govern the permeate flux in an anaerobic membrane bioreactor (AnMBR) treating municipal wastewater. Based on the survey, research to date indicates that the optimal membrane system for an AnMBR consists of an organic, hydrophilic, and negatively charged membrane with a pore size of approximately 0.1 microm. The use of both external and submerged membrane configurations shows promise. The operating parameters that affect permeate flux in an external membrane system are transmembrane pressure (TMP) and cross-flow velocity. The operating parameters that affect permeate flux in a submerged membrane system are TMP, sparging intensity, and duration of the relaxation period. Both cross-flow velocity and sparging intensity impart a significant amount of shear force on the biomass in an AnMBR. High shear forces can reduce the microbial activity in an AnMBR. In addition, high shear forces can reduce the size of the biosolids in the mixed liquor and increase the release of soluble microbial products. In this respect, external and submerged membrane systems are expected to perform differently because the magnitude of the shear forces to which the biomass is exposed in an external membrane system is significantly greater than that in a submerged system. The size of the biosolid particles and concentration of soluble microbial products in the mixed liquor affect permeate flux. Higher concentrations of soluble microbial products may be present in the mixed liquor when an AnMBR is operated at relatively low operating temperatures. Aerobic polishing following anaerobic treatment can potentially significantly reduce the concentration of some components of the soluble microbial products in the mixed liquor. It is not possible to remove the foulant layer on an organic membrane with caustic cleaning alone. Acidic cleaning or acidic cleaning followed by caustic cleaning is required to remove the foulant layer. This suggests that both biological/organic and inorganic material contribute to membrane fouling.

Anaerobiosis↗
PubMed2000

An overview of gastroesophageal reflux disease. Based on a presentation by M. Michael Wolfe, MD.

Gastroesophageal reflux disease (GERD) is a chronic acid-peptic disorder that is the combined result of several factors: 1) the lack of gastrointestinal motility coordination, 2) the failure of the lower esophageal sphincter to prevent reflux, and 3) the caustic nature of the gastric refluxate. Although GERD is very common, only a small fraction of sufferers consult a physician regarding their problem. This disease has a tremendous impact on both quality of life and overall health. If untreated, GERD can result in many serious complications, including erosive esophagitis, Barrett's esophagus, and esophageal adenocarcinoma. Because the caustic nature of the refluxate is a direct cause of esophageal damage, the cornerstone of GERD therapy is gastric acid suppression.

Gastroesophageal Reflux↗
PubMed2002

[Esophageal mucocele: report of 2 pediatric cases].

Two cases of esophageal mucocele in pediatric patients are reported: two children of 5 and 9 years respectively underwent surgical isolation of the esophagus and esophagocoloplasty for caustic stenosis related to accidental ingestion of caustic soda. Clinical pattern of mediastinal compression was proved with cervical fistulous tract in one case. In both cases, thoracic computed tomography was a sensitive imaging method to demonstrate the mucocele and its extension. Esophageal mucocele is rarely described in children, especially following esophageal corrosive stricture.

Burns, Chemical↗
PubMedDate not supplied

[ESOPHAGEAL STENOSIS IN CHILDREN: MEDICAL TREATMENT EXPERIENCE]

We present a retrospective evaluation of our experience in the period that goes from January 1992 to December 1998, clinical records of 58 patients ages from 2 months old to 15 years, male and female, who were treated at the GI service of Instituto de Salud del Ni o, were reviewed. All of them had esophageal stenosis and were included in the Esophageal Dilatation Program with Savary-Gilliard bougies. The causes of Esophageal Stenosis in the study were: Caustic agents 37.9%, gastro esophageal reflux (GER) 20.7%, surgery sequela 19.0%, related to esophageal esclerotherapy 12.1%, foreign body itself or maneuvers to retrieve them 8.6%, stomach adenocarcinoma invading the esophagus. Patients were classified in three groups: Group 1: stenosis due to caustic agents Group 2: stenosis due to GER Group 3: The remaining causes mentioned above., In each the following was calculated: the arithmetical media, the range of dilatations sessions and the total number of them. The higher figures took place in group 1. So we conclude that the number of sessions is directly related with the cause of the stenosis, requiring more number of dilatations to get a better response. Finally the response to treatment is evaluated considering a good response in 72.4%. A mild response in 15.5% and therapeutic failure in 12.1% of patients. The rate of complications was 10.3 per patient and 1.1 in relation to the total number of dilatation sessions. The main complications were: gastric perforation, duodenal perforation, pneumomediastinum, esophago-tracheal fistulae andi pseudodiverticulum formation, with resolution as seen in posterior controls. These complications occured after the proceeding took place. The treatment was installed according to each case. The patients with duodenal perforation died. We conclude that esophageal dilatations in infants with esophageal stenosis, of different ethiology, are secure and efficient.

Journal Article↗
PubMedDate not supplied

[INGESTION OF CORROSIVE SUBSTANCES]

Every patient that ingests any caustic substance still constitutes a medical and surgical. The severity and extension of the chemical damage will basically depend on the concentration and quantity of the caustic substance ingested. Likewise, when a highly concentrated alkali or acid substance is ingested, the esophagus and stomach will be damaged, and this lesion could also spread to the duodenum, and in some cases to the jejunum. Furthermore, it may compromise adjacent organs with a high morbimortality. The severity degree of the lesion can be determined with no risk by a flexible endoscopy, and correlates well with the intensity of tissue damage, enabling us to decide the manner in which this lesion is to be handled, with a prognosis value. A superficial grade (1 or 2a),will require no treatment and it will evolve without sequela. However, upon the determination of deep, ulcerated circumferential lesions, or with necrotic fundus by endoscopy (Grade 2b, and 3), patients shall be hospitalized and shall receive enteral or parenteral nutrition, as well as antibiotic protection. Careful attention should be given due to the risk of perforation or hemorrhage, and ocasionally, urgent surgical treatment will be necessary.The use of corticosteroids has proved to be innefective in preventing stenosis and is potentially dangerous. The most frequent late sequela is the developing of esophageal stenosis (developing in 50-70% of the 2b, and in all of the 3 who survive), and antral stenosis. The esophageal stenosis are tributaries of dilatations with bougies. An option to avoid stenosis, specially in children, is the placement of short plastic tubes, temporarily. In cases where there is no good response to the dilatations. or when the stenosis are long and multiple, surgery with interposition of colon or jejunum will be necessary. Usually, the development of gastric stenosis requires surgery. Motor alterations and gastroesophageal reflux as sequela may also be present, and belatedly, a greater risk to develoop squamous cancer.

Journal Article↗
PubMedDate not supplied

[Problems and difficulties in patients with esophageal reconstruction].

The esophageal reconstruction, independent of the manner and indication represents a major challenge for any surgical team. The goal of the present study is the retrospective analysis of cases together with the technical possibilities of surgical approach, viewed through the diagnostical and therapeutical point of view. We analysed retrospectively 154 patients (140 post-caustical stenosis and 14 neoplasms) who have took benefit of reconstructive esophageal surgery, operated in the last 21 years (1981-2001) in the clinic of surgery, of "Saint Mary" Hospital. Although the esophageal substitution has multiple indications (malignancy, benign stenosis, iatrogenic fistulas, reflux disease with peptic stenosis, etc.), in our clinic the technique was performed for neoplasic lesions and post-caustical corrosive stenosis. In the first period of the study (1981-1990) the most utilised method of surgical approach was the gastric tubulisation after the Gavriliu I or II procedures; in a second period (1990-2001) it is obvious that the tendency was to use the colon or the whole stomach as principal visceras for reconstructions. About the immediate results, the majority of post-operative complications where minors, the most frequent problem being of pleuro-pulmonary nature. We have registered two deceases of patients with corrosive pathology and no post-operative mortality in the first 30 days in neoplasic patients. We evaluated the post-operative functional results using an evaluation score. The anastomotic functionality was good or excellent in most cases (80%), especially in non-malignant reconstructions. For the selection of the most suitable reconstructive procedure, a variety of factors must be explored and evaluated. After a long period in which the use of the colon, in different technical manners, represented the "golden standard" in esophageal reconstruction, we have observed a reevaluation of this attitude and also the more and more frequent utilisation of the whole stomach as esophageal substitute, especially in malignancy.

Adolescent↗
PubMedDate not supplied

Childhood poisoning at the Obafemi Awolowo University Teaching Hospital, Ile-Ife, Nigeria.

A retrospective study of children admitted into the Children Emergency Room of the Obafemi Awolowo University Teaching Hospital, Ile-Ife, between 1989 and 1998 was undertaken. There were 127 cases constituting 0.52% of the total paediatric admissions over the study period. Poisoning was commoner among the lower socioeconomic classes and in males than females. 102 (80.3%) of the children involved were below the age of five years and poisoning was unintentional in 98.4%. Kerosene was the commonest agent accounting for 40.9% of all cases; followed by caustic soda (20.4%) and traditional mixtures (19.7%). Oral administration of palm oil is the commonest home remedy. Morbidity was commonest with caustic soda while traditional mixture was responsible for 80% of the mortality. Fifteen (11.9%) patients died constituting 0.84% of total childhood mortality during the study period. We conclude that childhood poisoning is still a significant cause of morbidity and mortality in children seen at the Obafemi Awolowo University Teaching Hospital. Improvement in the socioeconomic status of parents and health education on proper storage of household chemicals will help in reducing the incidence and mortality from poisoning.

Accidents, Home↗