Analysis of Factors Contributing to the Occurrence of Systemic Toxicity in Patients with Hydrofluoric Acid Skin Exposure Injury: An Individual Participant Data Meta-Analysis of 125 Clinical Cases from 1979 to 2020.

The purpose of this study is to analyze the factors contributing to the occurrence of systemic toxicity in patients injured after skin exposure to hydrofluoric acid (HFA) and to present guidelines for active treatment intervention based on this analysis. Data were acquired from EMBASE, PubMed, and Cochrane library for individual participant data (IPD) meta-analysis. Key searching terms included calcium gluconate (CAG), hydrofluoric acid, and case. This research consisted of case studies published between 1979 and 2020. Systemic toxicity was set as the main outcome. Data sets from 50 case studies (N = 125 participants) were analyzed. Multivariate binary logistic regression analyses of IPD found significant association effect of the total body surface area (TBSA) burned, indicating systemic toxicity [Regression coefficient estimate, 0.82; SE, 0.41; Odds ratio, 2.28; [95% confidence interval, 1.03-5.06], and p = 0.0424]. The optimal cutoff point (sensitivity; specificity) of the receiver operating characteristic curve of the total body surface area (TBSA) burned for contributing occurrence of systemic toxicity was 2.38(0.875; 0.959). IPD meta-analysis indicates that existing evidence supports the positive proportional association of the TBSA burned for systemic toxicity. If the TBSA burned (%) in patients exposed to hydrofluoric acid is greater than 2.38, early aggressive treatment intervention, including decontamination and various CAG application, should be recommended as the guideline.

Spacecraft Maximum Allowable Concentrations for Hydrogen Fluoride.

BACKGROUND: Spacecraft maximum allowable concentrations (SMACs) provide guidance on allowable chemical exposures for nominal and emergency situations aboard spacecraft. SMACs are set to mitigate or preclude potential crew health effects and performance degradation. Hydrogen fluoride (HF) gas is highly irritating. Inhaled HF produces irritation primarily in the upper respiratory tract. HF is not routinely present in spacecraft atmospheres. However, it can be produced in spacecraft due to overheating or combustion events involving materials containing fluorinated organics.METHODS: Toxicological data relevant to SMAC development were collected from electronic databases using principles of systematic review, and from previous assessments and reviews of HF.RESULTS: The human inhalation data of Lund (short-term) and Largent (subchronic) showed that HF at approximately 3 ppm caused very mild respiratory irritation. NASA HF SMACs are based on these findings.DISCUSSION: The 1-h and 24-h SMACs are set at 3 ppm, a value consistent with NASA short-term SMAC criteria where crew may experience mild irritation. The 7-d, 30-d, 180-d, and 1000-d SMACs are set at 0.3 ppm to protect against any long-term crew health or performance effects that could be produced from HF exposures.Lam C-W, Ryder VE. Spacecraft maximum allowable concentrations for hydrogen fluoride. Aerosp Med Hum Perform. 2022; 93(10):746-748.

"Breaking heart" due to hydrofluoric acid burns in a case of homicide.

Homicide attacks in which hydrofluoric acid (HF) is used are very rare, and few studies have reported the pathological changes. Hypocalcemia is thought to be the cause of sudden death from HF; nevertheless, after neutralization of the blood concentration of calcium ions, HF-induced arrhythmia may still occur, suggesting that in addition to hypocalcemia, direct toxic effects of HF may play a pivotal role in myocardial damage. Here, we report a homicidal forensic autopsy case with pathological changes of the myocardium due to HF burns. Von Kossa staining and immunohistochemical staining were also performed. The cause of death was given as HF toxicity with direct toxic effects on myocardial damage as ischemic injury may occur prior to ventricular fibrillation in the present case. The present case shows that myocardial damage should be given more attention in the clinical treatment and forensic autopsy of HF burns.

[Research advances on the treatment of hydrofluoric acid burns].

Hydrofluoric acid is a highly dangerous and toxic inorganic acid, which is widely used in industrial fields and daily life. The risk of hydrofluoric acid burns is related to hydrofluoric acid mass fraction, duration of exposure to hydrofluoric acid, burn area, burn depth, and burn site, etc. Hydrofluoric acid has strong toxicity and tissue penetration ability. A small area of hydrofluoric acid burns can cause death in a short time. Therefore, improving the understanding of the mechanism of hydrofluoric acid burns and learning how to treat hydrofluoric acid burns in different sites can further improve the cure rate of hydrofluoric acid burns.

[Epidemiological characteristics and treatment outcome analysis of 229 patients with hydrofluoric acid burns in hands].

Objective: To explore the epidemiological characteristics and treatment outcomes of patients with hydrofluoric acid burns in hands. Methods: A retrospective observational study was conducted. The medical records of 229 patients with hydrofluoric acid burns in hands who were admitted to Zhejiang Quhua Hospital from January 2008 to December 2020 and met the inclusion criteria were collected. The following statistical data of patients were collected, including gender, age, type of affiliated enterprise, hydrofluoric acid mass fraction, injury site, total burn area, prehospital time, length of hospital stay, length of wound healing, whether hypocalcemia and hypomagnesemia occurred or not on admission, whether surgery intervention was performed or not, and whether scar sequelae occurred or not. Single factor and multivariate logistic regression analysis were used to screen out the risk factors impacting surgery intervention and scar sequelae of all the patients and patients whose hydrofluoric acid mass fraction was known. Single factor and multivariate linear regression analysis were used to screen out the risk factors impacting the length of wound healing of all the patients and patients whose hydrofluoric acid mass fraction was known. Results: The 229 patients included 206 males and 23 females, with the majority aged 30 to 50 years (139 patients). The type of affiliated enterprise of majority patients was non-fluorine chemical enterprise. The hydrofluoric acid mass fraction was known in only 91 patients, mainly medium. The majority injury site was in the middle and end of finger. The total burn area was below or equal to 1% total body surface area. The prehospital time was 19 (9, 29) h. The length of hospital stay was 2 (1, 7) d. The length of wound healing was 12 (8, 18) d. The proportions of hypocalcemia and hypomagnesemia were 0.9% (2/229) and 1.3% (3/229) on admission, respectively. Thirty-six patients had surgeries and 83 patients had scar sequelae. In 229 patients, single factor logistic regression analysis showed that both type of affiliated enterprise and prehospital time were the factors impacting surgery intervention (with odds ratio values of 7.86 and 51.35, respectively, 95% confidence intervals of 1.83-33.76 and 11.89-221.78, respectively, P<0.01) and scar sequelae of patients (with odds ratio values of 3.62 and 27.40, respectively, 95% confidence intervals of 1.76-7.43 and 13.25-56.68, respectively, P<0.01); multivariate logistic regression analysis showed that prehospital time was the independent risks factor impacting surgery intervention and scar sequelae of patients (with odds ratio values of 43.00 and 24.55, respectively, 95% confidence intervals of 9.89-187.03 and 11.78-51.16, respectively, P<0.01); single factor linear regression analysis showed that both type of affiliated enterprise and prehospital time were the factors impacting the length of wound healing of patients (with ß values of 6.16 and 12.83, respectively, 95% confidence intervals of 3.38-8.93 and 10.72-14.93, respectively, P<0.01); multivariate linear regression analysis showed that both type of affiliated enterprise and prehospital time were the independent risk factors impacting the length of wound healing of patients (with ß values of 2.81 and 12.16, respectively, 95% confidence intervals of 0.50-5.13 and 10.00-14.31, respectively, P<0.05 or P<0.01). In 91 patients whose hydrofluoric acid mass fraction was known, single factor logistic regression analysis showed that type of affiliated enterprise, hydrofluoric acid mass fraction (low and high), and prehospital time were all the factors impacting surgery intervention of patients (with odds ratio values of 9.10, 11.25, 10.69, and 0.04, respectively, 95% confidence intervals of 1.15-72.25, 1.39-90.93, 1.32-86.59, and 0.01-0.19, respectively, P<0.05 or P<0.01), type of affiliated enterprise, hydrofluoric acid mass fraction, and prehospital time were all the factors impacting scar sequelae of patients (with odds ratio values of 0.32, 0.21, and 36.80, respectively, 95% confidence intervals of 0.11-0.92, 0.06-0.73, and 11.03-122.79, respectively, P<0.05 or P<0.01); multivariate logistic regression analysis showed that both hydrofluoric acid mass fraction and prehospital time were the independent risk factors impacting surgery intervention of patients (with odds ratio values of 11.51 and 0.04, respectively, 95% confidence intervals of 1.22-108.26 and 0.01-0.25, respectively, P<0.05 or P<0.01), prehospital time was the independent risk factor impacting scar sequelae of patients (odds ratio=37.71, with 95% confidence interval of 9.97-142.69, P<0.01); single factor linear regression analysis showed that type of affiliated enterprise, hydrofluoric acid mass fraction (low and high), and prehospital time were all the factors impacting the length of wound healing of patients (with ß values of 7.12, -5.63, -9.74, and 13.50, respectively, 95% confidence intervals of 2.43-11.81, -10.59--0.68, -14.78--4.70, and 10.14-16.86, respectively, P<0.05 or P<0.01); multivariate linear regression analysis showed that both hydrofluoric acid mass fraction and prehospital time were the independent risk factors impacting the length of wound healing of patients (with ß values of -5.84 and 0.09, respectively, 95% confidence intervals of -10.59--1.08 and 0.05-0.12, respectively, P<0.05 or P<0.01). Conclusions: The majority of patients with hydrofluoric acid burns in hands are young and middle-aged males. Type of affiliated enterprise, hydrofluoric acid mass fraction and prehospital time are the risk factors that affect the treatment outcomes of patients with hydrofluoric acid burns in hands.

Comparative Analysis of Hydrogen Fluoride-Exposed Patients Based on Major Burn Criteria After the 2012 Gumi City Chemical Leak Disaster.

This study conducted to analyze and compare the epidemiological and clinical characteristics of hydrogen fluoride-exposed patients based on major burn criteria for the appropriate emergency department (ED) response to a mass casualty chemical spill. This retrospective cross-sectional study included the records of patients (n = 199) who visited the ED of Gumi City University Hospital from September 27, 2012, to October 20, 2012. Subjects were included in the major burn group (MBG) if they presented with wounds that required referral to a burn center according to the American Burn Association guidelines or in the nonmajor burn group (NMBG) if not. Males were predominant in both the MBG (n = 55, 48 males) and NMBG (n = 144, 84 males; P < .05). The most prevalent timeline for visiting the ED was the phase which included 9-32 hours post-leak of hydrogen fluoride, including 45 patients (81.8%) in the MBG and 122 patients (84.7%) in the NMBG (P < .001). The respiratory tract was the site of greatest damage in patients in both the MBG and NMBG (n = 47, 85.5% vs n = 142, 98.6%, P < .001). Regarding dispositions, all patients in the NMBG were discharged (n = 144, 100%); however, eight patients (14.5%) in the MBG underwent other dispositions (discharge against medical advice, five patients; admission, one patient; death, two patients, P < .05). Patient outcomes after major chemical contamination events should be characterized in future studies to maximize the quality of patient care.

Epidemiological characteristics and treatment outcome analysis of 229 patients with hydrofluoric acid burns in hands / 中华烧伤杂志

Objective: To explore the epidemiological characteristics and treatment outcomes of patients with hydrofluoric acid burns in hands. Methods: A retrospective observational study was conducted. The medical records of 229 patients with hydrofluoric acid burns in hands who were admitted to Zhejiang Quhua Hospital from January 2008 to December 2020 and met the inclusion criteria were collected. The following statistical data of patients were collected, including gender, age, type of affiliated enterprise, hydrofluoric acid mass fraction, injury site, total burn area, prehospital time, length of hospital stay, length of wound healing, whether hypocalcemia and hypomagnesemia occurred or not on admission, whether surgery intervention was performed or not, and whether scar sequelae occurred or not. Single factor and multivariate logistic regression analysis were used to screen out the risk factors impacting surgery intervention and scar sequelae of all the patients and patients whose hydrofluoric acid mass fraction was known. Single factor and multivariate linear regression analysis were used to screen out the risk factors impacting the length of wound healing of all the patients and patients whose hydrofluoric acid mass fraction was known. Results: The 229 patients included 206 males and 23 females, with the majority aged 30 to 50 years (139 patients). The type of affiliated enterprise of majority patients was non-fluorine chemical enterprise. The hydrofluoric acid mass fraction was known in only 91 patients, mainly medium. The majority injury site was in the middle and end of finger. The total burn area was below or equal to 1% total body surface area. The prehospital time was 19 (9, 29) h. The length of hospital stay was 2 (1, 7) d. The length of wound healing was 12 (8, 18) d. The proportions of hypocalcemia and hypomagnesemia were 0.9% (2/229) and 1.3% (3/229) on admission, respectively. Thirty-six patients had surgeries and 83 patients had scar sequelae. In 229 patients, single factor logistic regression analysis showed that both type of affiliated enterprise and prehospital time were the factors impacting surgery intervention (with odds ratio values of 7.86 and 51.35, respectively, 95% confidence intervals of 1.83-33.76 and 11.89-221.78, respectively, P<0.01) and scar sequelae of patients (with odds ratio values of 3.62 and 27.40, respectively, 95% confidence intervals of 1.76-7.43 and 13.25-56.68, respectively, P<0.01); multivariate logistic regression analysis showed that prehospital time was the independent risks factor impacting surgery intervention and scar sequelae of patients (with odds ratio values of 43.00 and 24.55, respectively, 95% confidence intervals of 9.89-187.03 and 11.78-51.16, respectively, P<0.01); single factor linear regression analysis showed that both type of affiliated enterprise and prehospital time were the factors impacting the length of wound healing of patients (with β values of 6.16 and 12.83, respectively, 95% confidence intervals of 3.38-8.93 and 10.72-14.93, respectively, P<0.01); multivariate linear regression analysis showed that both type of affiliated enterprise and prehospital time were the independent risk factors impacting the length of wound healing of patients (with β values of 2.81 and 12.16, respectively, 95% confidence intervals of 0.50-5.13 and 10.00-14.31, respectively, P<0.05 or P<0.01). In 91 patients whose hydrofluoric acid mass fraction was known, single factor logistic regression analysis showed that type of affiliated enterprise, hydrofluoric acid mass fraction (low and high), and prehospital time were all the factors impacting surgery intervention of patients (with odds ratio values of 9.10, 11.25, 10.69, and 0.04, respectively, 95% confidence intervals of 1.15-72.25, 1.39-90.93, 1.32-86.59, and 0.01-0.19, respectively, P<0.05 or P<0.01), type of affiliated enterprise, hydrofluoric acid mass fraction, and prehospital time were all the factors impacting scar sequelae of patients (with odds ratio values of 0.32, 0.21, and 36.80, respectively, 95% confidence intervals of 0.11-0.92, 0.06-0.73, and 11.03-122.79, respectively, P<0.05 or P<0.01); multivariate logistic regression analysis showed that both hydrofluoric acid mass fraction and prehospital time were the independent risk factors impacting surgery intervention of patients (with odds ratio values of 11.51 and 0.04, respectively, 95% confidence intervals of 1.22-108.26 and 0.01-0.25, respectively, P<0.05 or P<0.01), prehospital time was the independent risk factor impacting scar sequelae of patients (odds ratio=37.71, with 95% confidence interval of 9.97-142.69, P<0.01); single factor linear regression analysis showed that type of affiliated enterprise, hydrofluoric acid mass fraction (low and high), and prehospital time were all the factors impacting the length of wound healing of patients (with β values of 7.12, -5.63, -9.74, and 13.50, respectively, 95% confidence intervals of 2.43-11.81, -10.59--0.68, -14.78--4.70, and 10.14-16.86, respectively, P<0.05 or P<0.01); multivariate linear regression analysis showed that both hydrofluoric acid mass fraction and prehospital time were the independent risk factors impacting the length of wound healing of patients (with β values of -5.84 and 0.09, respectively, 95% confidence intervals of -10.59--1.08 and 0.05-0.12, respectively, P<0.05 or P<0.01). Conclusions: The majority of patients with hydrofluoric acid burns in hands are young and middle-aged males. Type of affiliated enterprise, hydrofluoric acid mass fraction and prehospital time are the risk factors that affect the treatment outcomes of patients with hydrofluoric acid burns in hands.

Critical care management of hydrofluoric acid burns with a negative outcome.

Hydrofluoric acid is a highly corrosive acid widely used in various industries. When in contact with skin it causes local and systemic reactions due to the generation of fluoride ions. Severe burns are associated with high mortality rates, approaching 100%. We present a 21-year-old man with 15% full thickness burns, severe metabolic acidosis, hypoxia and electrolyte disturbances. The burns were treated with topical and subcutaneous injections of calcium gluconate, and the patient was given intravenous fluid, calcium chloride, magnesium and insulin-glucose infusions. Continuous renal replacement therapy was initiated due to the severity of the systemic toxicity. Extracorporeal membrane oxygenation was considered as it plays a vital role when conventional therapies fail. Our patient suffered multiple cardiac arrests and cardiopulmonary resuscitation was conducted several times but despite extensive efforts, he did not survive.

Management of a Man With Hydrofluoric Acid Burns: A Case Report and Review.

A hydrofluoric acid (HFA) burn is a severe condition with the characteristics of acute onset, rapid progression, and high complication and mortality rates. Emergency and systemic treatments are especially important for major HFA burns. The author presents the case of a 46-year-old man burned by the spillage of HFA at a high concentration (45-50%). He suffered burns over 30% of his total body area (5% deep partial-thickness burns and 25% third-degree burns). Debridement, tangential excision, and electrolyte therapy were quickly performed for urgent treatment. Symptomatic treatment was sustained to address severe complications and recurrent injury. For successful management, the patient was stabilized, and he exhibited complete wound repair after 3 months. The author summarizes severe cases of HFA burns to emphasize the difficulty of treatment. The existing approved therapies and complications are discussed, and the significance of electrolyte disorders, especially hypocalcemia, is highlighted. The pathophysiology of HFA burns and recommendations for the treatment of HFA burns at different sites are presented to provide a relatively complete treatment guideline focused on electrolyte disorders.

Toxicidad por ácido fluorhídrico: reporte de casos / HYdrofluoric acid toxicity

Los accidentes con ácido fluorhídrico en Argentina son un motivo de consulta infrecuente, a pesar de ser utilizado en varias actividades laborales. Es uno de los pocos cáusticos con tratamiento específico que se debe tener en cuenta. Reportamos el caso de un paciente de 35 años que estuvo en contacto con esta sustancia con posterior compromiso de miembro superior, presentando placa eritematosa en región palmar derecha y lesión ampollar con descamación posterior y sangrado en lecho ungueal. Recibió tratamiento local con gluconato de calcio al 20% en toda la extensión de la zona afectada durante 48 hs con recuperación completa a los quince días. La sospecha clínica temprana y la administración adecuada de gluconato de calcio evitan lesiones de mayor grado y extensión

In Argentina, hydrofluoric acid accidents are a rare reason for consultation, despite being a commonly used substance in laboral activities. It is one of the few caustics with a specific treatment that must be taken into account. We report the case of a 35 year old patient affected by said substance, in which we observe an impairment of the upper limb, presenting on the right palmar region, an erythematous plaque with a blister lesion with posterior scaling and bleeding of the nail bed. The importance of the early clinical suspicion and the proper administration of calcium gluconate would avoid bigger and more extensive lesions

Clinical significance of urinary fluoride levels in patients with hydrofluoric acid burns.

OBJECTIVE: We investigated the urinary fluoride level in patients with hydrofluoric acid (HF) burns of different severities and explored the clinical significance of these levels in the diagnosis of acute HF burn. METHODS: Data from 260 patients with HF burns were collected from the Department of Burns, Zhejiang Quhua Hospital, between July 2006 and June 2016. According to burn severity, patients were divided into non-poisoning, mild poisoning, moderate poisoning, and severe poisoning groups. In addition, 25 healthy controls were recruited from fluorine chemical companies. The urinary fluoride level was measured using a fluoride-selective electrode and values were compared amongst groups. The urinary fluoride level was also measured periodically after exposure to investigate dynamic changes in the moderate and severe poisoning groups. RESULTS: Urinary fluoride levels were 0.32-520.0mg/L (n=260) on admission to the emergency department, and 182 patients had levels >1.7mg/L. The levels in controls and the non-poisoning group were lower than in the other two groups, and increased significantly with an increase in severity. Thirty-three patients were admitted 4h after injury; of these patients, fluoride levels were significantly higher in those with severe poisoning than in those with moderate poisoning. Levels peaked 4h after injury and then dropped and returned to normal 6days after injury. CONCLUSION: Urinary fluoride level can be used for the early diagnosis of HF burns and to determine the severity of fluoride poisoning, which is crucial for early treatment.

High Throughput SiRNA Screening for Chloropicrin and Hydrogen Fluoride-Induced Cornea Epithelial Cell Injury.

Toxicant-induced ocular injury is a true ocular emergency because chemicals have the potential to rapidly inflict significant tissue damage. Treatments for toxicant-induced corneal injury are generally supportive as no specific therapeutics exist to treat these injuries. In the efforts to develop treatments and therapeutics to care for exposure, it can be important to understand the molecular and cellular mechanisms of these injuries. We propose that utilization of high throughput small inhibitory RNA (siRNA) screening can be an important tool that could help to more rapidly elucidate the molecular mechanisms of chemical cornea epithelial injury. siRNA are double stranded RNA molecules that are 19-25 nucleotides long and utilize the post-transcriptional gene silencing pathway to degrade mRNA which have homology to the siRNA. The resulting reduction of expression of the specific gene can then be studied in toxicant exposed cells to ascertain the function of that gene in the cellular response to the toxicant. The development and validation of in vitro exposure models and methods for the high throughput screening (HTS) of hydrogen fluoride- (HF) and chloropicrin- (CP) induced ocular injury are presented in this article. Although we selected these two toxicants, our methods are applicable to the study of other toxicants with minor modifications to the toxicant exposure protocol. The SV40 large T antigen immortalized human corneal epithelial cell line SV40-HCEC was selected for study. Cell viability and IL-8 production were selected as endpoints in the screening protocol. Several challenges associated with the development of toxicant exposure and cell culture methods suitable for HTS studies are presented. The establishment of HTS models for these toxicants allows for further studies to better understand the mechanism of injury and to screen for potential therapeutics for chemical ocular injury.

[Analysis on clinical characteristics of 316 patients with hydrofluoric acid burns].

Objective: To investigate the clinical characteristics of patients with hydrofluoric acid (HF) burns. Methods: Clinical data of 316 patients with HF burns admitted to Zhejiang Quhua Hospital from January 2004 to December 2016 were retrospectively analyzed. Patients were divided into non and mild poisoning group (NMP, n=157), moderate poisoning group (MP, n=120), and severe and fatal poisoning group (SFP, n=39) based on the severity of poisoning. Occurrences of hypocalcemia, hypomagnesemia, hypokalemia, and hyperkalemia of patients within 24 hours after admission were recorded. Values of emergency urinary fluoride of patients on admission were recorded. Values of urinary fluoride of patients admitted to hospital in 4 hours post injury in groups MP and SFP at post injury hour 4, 12, and 24 and on post injury day 2, 3, 4, 5, 6, and 7 were also recorded. Electrocardiographic abnormalities of patients within 24 hours after admission were recorded. Data were processed with chi-square test, Kruskal-Wallis H test, and Mann-Whitney U test. Results: (1) Hypocalcemia, hypomagnesemia, and hypokalemia occurred in some patients in each of the three groups, but no patient had hyperkalemia. Taking serum calcium namely total serum calcium as reference, the incidence rate of hypocalcemia of patients in group NMP was close to that in group MP (χ(2)=0.05, P>0.05). The incidence rate of hypocalcemia of patients in group SFP was significantly higher than that in group NMP or group MP (χ(2)=10.53, 7.92, P<0.01). The incidence rates of hypokalemia in the three groups were close (χ(2)=0.63, P>0.05). Taking serum ionized calcium as reference, the incidence ratio of hypocalcemia of patients in group NMP was close to that in group MP (χ(2)=0.01, P>0.05), while there were statistically significant differences in incidence ratio of hypocalcemia of patients between group SFP and each of group NMP and group MP (χ(2)=4.66, 4.47, P<0.05). Taking serum calcium as reference, the incidence rate of hypocalcemia of patients was 7.3% (23/316). Taking serum ionized calcium as reference, the incidence rate of hypocalcemia of patients was 60.0% (42/70), which was significantly higher than that of taking serum calcium as reference (χ(2)=113.74, P<0.01). The incidence rates of hypomagnesemia of patients in groups MP and NMP were close (χ(2)=0.02, P>0.05). The incidence rate of hypomagnesemia of patients in group SFP was significantly higher than that in group NMP or group MP (χ(2)=14.69, 9.94, P<0.01). (2) The urinary fluoride levels were tested in 288 patients, with the value of emergency urinary fluoride of patients on admission 0.2-590.0 mg/L. The values of urinary fluoride of 202 patients were above the normal value. The values of emergency urinary fluoride of patients in groups NMP, MP, and SFP were 2.15 (1.11, 4.30), 5.89 (1.72, 14.25), and 36.0 (13.2, 103.2) mg/L, respectively. The values of emergency urinary fluoride of patients in groups MP and SFP were significantly higher than the value in group NMP (χ(2)=23.28, 66.03, P<0.01). The value of emergency urinary fluoride of patients in group SFP was significantly higher than that in group MP (χ(2)=39.23, P<0.01). The value of urinary fluoride of 33 patients admitted to hospital within 4 hours post injury in groups MP and SFP reached the top at 4 hours post injury and then gradually declined, which returned to normal on about 5 days post injury. The values of urinary fluoride of patients in group SFP at 4, 12, and 24 hours post injury and on 2, 3, 4, 5, 6, and 7 days post injury were significantly higher than those in group MP (Z=-4.28, -4.15, -3.81, -4.21, -2.48, -2.06, -2.31, -2.68, -3.03, P<0.05 or P<0.01). (3) Twenty-seven patients had electrocardiographic abnormality. There were 12 patients with T wave changes (the most common), 8 patients with ST-T changes, 6 patients with ventricular arrhythmias, 6 patients with conduction block, and 1 patient with broadened QRS waveform. There was no patient with prolonged Q-T interval. The ratios of patients with the above electrocardiographic abnormalities in group SFP were higher than those in group NMP and group MP. Conclusions: Clinical manifestations of patients with HF burn are hypocalcemia, hypomagnesemia, hypokalemia, and electrocardiographic abnormality. In addition to routine serum electrolyte and electrocardiogram monitoring, the levels of serum ionized calcium and urinary fluoride can be helpful to evaluate the severity of illness of the patients.

[Analysis on effects of modified dosage of calcium gluconate on patients with hydrofluoric acid burns not in hands or feet].

Objective: To retrospectively explore the effects of modified dosage of calcium gluconate (CG) on the patients with hydrofluoric acid burns not in hands or feet. Methods: One hundred and sixty patients with hydrofluoric acid burns not in hands or feet were hospitalized in our burn ward from January 2004 to December 2017. Based on the dosage of CG at different admission time, 76 patients hospitalized from January 2004 to December 2012 were included in traditional group, and 84 patients hospitalized from January 2013 to December 2017 were included in modified group. For patients in the two groups, subcutaneous injection of CG solution at one time was immediately conducted on admission in topical treatment. In traditional group, the injection was CG solution with mass concentration of 100 g/L. For wounds of superficial partial-thickness and above degree, CG solution was prescribed at the dosage of 50 mg/cm(2). Wounds of superficial-thickness or mass fraction of hydrofluoric acid less than 20.0% did not receive injection. In modified group, the mass concentration of CG solution for injection was diluted with normal saline to 25 g/L. For wounds of deep partial-thickness and above degree, CG solution was prescribed at the dosage of (50×mass fraction of hydrofluoric acid) mg/cm(2). For wounds of superficial partial-thickness, CG solution was prescribed at the dosage of (25×mass fraction of hydrofluoric acid) mg/cm(2). For wounds of superficial-thickness, CG solution was prescribed at the dosage of 2.5 mg/cm(2). For systemic treatment, the injection velocity of CG solution via venous access was adjusted according to the level of serum calcium namely total serum calcium of patients in traditional group. In modified group, serum ionized calcium was additionally detected through automatic blood gas analyzer by the bed to regulate the injection velocity of CG via venous access. The incidence rate of hypercalcemia and mortality of patients after treatment in the two groups, and the situation about treatment of survivors in the two groups were analyzed. Data were processed with chi-square test, Fisher's exact probability test, t test, and Mann-Whitney U test. Results: (1) After treatment, 9 patients (11.8%) had hypercalcemia, while the other 67 patients (88.2%) did not have hypercalcemia in traditional group. Two patients (2.4%) had hypercalcemia, while the other 82 patients (97.6%) did not have hypercalcemia in modified group. The incidence rate of hypercalcemia of patients in traditional group was significantly higher than that in modified group (χ(2)=5.579, P=0.02). (2) There were two deaths (2.6%) and 74 survivors (97.4%) in traditional group, while there were two deaths (2.4%) and 82 survivors (97.6%) in modified group. The mortalities of patients in the two groups were close (P>0.05). (3) The ratios of eschar excision and skin grafting and hyperplastic scar formation, wound healing time, and ratio of esophageal scar stenosis of survivors in the two groups were close (χ(2)=0.002, 0.054, Z=0.66, P>0.05). Conclusions: Hydrofluoric acid is highly dangerous. The early management of patients with hydrofluoric acid burns emphasizing specialized dosage of CG for treatment can be helpful to reduce incidence of complications and improve the safety of treatment.

Alternativas de tratamientos de superficie para adhesión de cerámica de disilicado de litio / Alternatives of surface treatments for adhesion of lithium disilicate ceramics

Introduction: the clinical success of a restoration is strongly associated with the quality and durability of the ceramic-cement resin interface. In order to obtain an adequate union between these materials of different nature surface treatments are used and achieve mechanical retention or chemical interaction. Objectives: to check if any method promotes a true chemical bond between lithium disilicate ceramics and resin cement. As well as determineif there is any treatment that reports bonding values comparable to hydrofluoric acid and silane (gold standard). Methods: a systematic literature review was developed based on the PRISMA strategy, where the databases were searched: Science Direct, Pubmed (MEDLINE), EMBASE, Springer Journal, SciELO with MeSH and free terms from 2005 to November 2016 for articles in English and Spanish on surface treatments for lithium disilicate. Results: from 58 publications selected a sample of 21 articles. Two articles reported high risk of bias. Conclusions: hydrofluoric acid and silane continue to be the method with the highest and most reliable adhesion values in the literature. Universal adhesives are an alternative to promote chemical adhesion additional to the silane. Diamond burs, Nd: YAG and Er: YAG laser are not recommended as surface treatments(AU)

Introducción: el éxito clínico de una restauración se asocia fuertemente a la calidad y duración de la interface cerámica-cemento resinoso. Para que exista una adecuada unión entre estos materiales de distinta naturaleza se emplean tratamientos de superficie para lograr una buena retención mecánica o interacción química. Objetivos: revisar si algún método promueve una verdadera adhesión química entre la cerámica de disilicato de litio y el cemento resinoso, así como determinar si existe algún tratamiento que reporte valores de unión comparables al ácido fluorhídrico y silano (patrón de oro). Métodos: se desarrolló una revisión sistemática de literatura basada en la estrategia PRISMA, donde se buscó en las bases de datos: Science Direct, Pubmed (MEDLINE), EMBASE, Springer Journal, SciELO con términos MeSH y libres desde el 2005 a noviembre de 2016 para artículos en inglés y español sobre tratamientos de superficie para disilicato de litio. Resultados: de 58 publicaciones, se seleccionó una muestra de 21 artículos. Dos artículos reportaron riesgo de sesgo alto. Conclusiones: el ácido fluorhídrico y silano continúan siendo el método con los valores de adhesión más altos y confiables de la literatura. Los adhesivos universales son una alternativa para promover adhesión química adicional al silano. Fresas diamantadas, laser Nd: YAG y Er:YAG no se recomienda como tratamientos de superficie(AU)

Alternativas de tratamientos de superficie para adhesión de cerámica de disilicado de litio / Alternatives of surface treatments for adhesion of lithium disilicate ceramics

Introduction: the clinical success of a restoration is strongly associated with the quality and durability of the ceramic-cement resin interface. In order to obtain an adequate union between these materials of different nature surface treatments are used and achieve mechanical retention or chemical interaction. Objectives: to check if any method promotes a true chemical bond between lithium disilicate ceramics and resin cement. As well as determineif there is any treatment that reports bonding values comparable to hydrofluoric acid and silane (gold standard). Methods: a systematic literature review was developed based on the PRISMA strategy, where the databases were searched: Science Direct, Pubmed (MEDLINE), EMBASE, Springer Journal, SciELO with MeSH and free terms from 2005 to November 2016 for articles in English and Spanish on surface treatments for lithium disilicate. Results: from 58 publications selected a sample of 21 articles. Two articles reported high risk of bias. Conclusions: hydrofluoric acid and silane continue to be the method with the highest and most reliable adhesion values in the literature. Universal adhesives are an alternative to promote chemical adhesion additional to the silane. Diamond burs, Nd: YAG and Er: YAG laser are not recommended as surface treatments(AU)

Introducción: el éxito clínico de una restauración se asocia fuertemente a la calidad y duración de la interface cerámica-cemento resinoso. Para que exista una adecuada unión entre estos materiales de distinta naturaleza se emplean tratamientos de superficie para lograr una buena retención mecánica o interacción química. Objetivos: revisar si algún método promueve una verdadera adhesión química entre la cerámica de disilicato de litio y el cemento resinoso, así como determinar si existe algún tratamiento que reporte valores de unión comparables al ácido fluorhídrico y silano (patrón de oro). Métodos: se desarrolló una revisión sistemática de literatura basada en la estrategia PRISMA, donde se buscó en las bases de datos: Science Direct, Pubmed (MEDLINE), EMBASE, Springer Journal, SciELO con términos MeSH y libres desde el 2005 a noviembre de 2016 para artículos en inglés y español sobre tratamientos de superficie para disilicato de litio. Resultados: de 58 publicaciones, se seleccionó una muestra de 21 artículos. Dos artículos reportaron riesgo de sesgo alto. Conclusiones: el ácido fluorhídrico y silano continúan siendo el método con los valores de adhesión más altos y confiables de la literatura. Los adhesivos universales son una alternativa para promover adhesión química adicional al silano. Fresas diamantadas, laser Nd: YAG y Er:YAG no se recomienda como tratamientos de superficie(AU)