Clinical Toxicology (2014), 52, 44–47 Copyright © 2014 Informa Healthcare USA, Inc. ISSN: 1556-3650 print / 1556-9519 online DOI: 10.3109/15563650.2013.863327
CRITICAL CARE
Life-threatening methemoglobinemia after unintentional ingestion of antifreeze admixtures containing sodium nitrite in the construction sites C. H. SOHN, D. W. SEO, S. M. RYOO, J. H. LEE, W. Y. KIM, K. S. LIM, and B. J. OH Department of Emergency Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea
Context. Construction workers are exposed to a wide variety of health hazards such as poisoning at the construction sites. Various forms of poisoning incidents in construction workers have been reported. However, studies on methemoglobinemia caused by unintentional ingestion of antifreeze admixtures containing sodium nitrite at the construction sites have not been reported yet. Objective. The aim of this study was to evaluate life-threatening methemoglobinemia after unintentional ingestion of antifreeze admixtures containing sodium nitrite at the construction sites and describe similar incidents involving ingestion of antifreeze admixtures in Korea. Materials and methods. Retrospective observational case series study on patients with methemoglobinemia after unintentional ingestion of antifreeze admixtures containing sodium nitrite admitted to the emergency department (ED) from January 1, 2010 to December 31, 2012 and cases reported to the Korea Occupational Safety and Health Agency (KOSHA) was performed. Results. Six victims were admitted to our ED. They had methemoglobin levels ranging from 32.4% to 71.5% and all of them recovered after receiving one (2 mg/kg) or two doses infusion of methylene blue. From the data of the KOSHA, six incidents that caused 27 victims were identified. Of 27 victims, five were included in the ED cases. For all incidents, antifreeze admixtures were not contained in their original containers and all new containers did not have a new label. All workers mistook antifreeze admixtures for water. Among the 28 victims included in this study, four died. Conclusion. Unintentional ingestion of antifreeze admixtures containing sodium nitrite at the construction sites can cause life-threatening methemoglobinemia. There is a need to store and label potentially hazardous materials properly to avoid unintentional ingestion at the construction sites. Keywords Methemoglobinemia; Sodium nitrite; Antifreeze admixtures; Construction sites
Introduction
sodium nitrite at the construction sites have not been reported yet. Recently in South Korea, workers at the construction sites died after eating the instant cup noodle using boiled antifreeze admixtures mistaken for water.13 The aim of this study was to evaluate the clinical characteristics and outcomes of patients who were diagnosed with methemoglobinemia after unintentional ingestion of antifreeze admixtures containing sodium nitrite at the construction sites and describe similar incidents involving ingestion of antifreeze admixtures in Korea.
Methemoglobinemia occurs when hemoglobin is oxidized to form methemoglobin (MetHb), in which the iron in the heme group is in the Fe3⫹ (ferric) state, not the Fe2⫹ (ferrous) of normal hemoglobin, rendering it incapable of oxygen transport and leading to tissue hypoxia in severe cases.1 The most common cause of methemoglobinemia is ingestion of an oxidizing agent such as nitrites.2 Sodium nitrites are common antifreeze compounds used for cold weather concreting.3 Because antifreeze admixtures containing sodium nitrite are colorless and odorless, these substances can be mistaken for water. Many cases of methemoglobinemia caused by sodium nitrites in a variety of situations have been reported.4–12 However, to date, studies on methemoglobinemia caused by unintentional ingestion of antifreeze admixtures containing
Methods This retrospective observational case series study was performed at the emergency department (ED) of Asan Medical Center, a tertiary care university-affiliated hospital in Seoul, Korea. The study patients were initially identified via a hospital computer database system using a hospital discharge diagnosis with methemoglobinemia from January 1, 2010 to December 31, 2012. Finally, patients with methemoglobinemia associated with incidents involving unintentional ingestion of antifreeze admixtures were included. This study was approved by the ethics committee of our institution.
Received 7 May 2013; accepted 3 November 2013. Address correspondence to Dong Woo Seo, MD, Department of Emergency Medicine, University of Ulsan College of Medicine, Asan Medical Center, Asanbyeongwon-gil 86, Sonpa-gu, Seoul 138-736, Republic of Korea. Tel: ⫹ 82-2-3010-3350. Fax: ⫹ 82-2-3010-3360. E-mail: [email protected]
44
Methemoglobinemia due to antifreeze admixtures 45 And to enhance the knowledge of this pattern of poisoning occurring at the construction sites, the authors identified further incidents in Korea by using the keyword ‘antifreeze in Korean) on the website of the admixture’ ( Korea Occupational Safety and Health Agency (KOSHA).13 All antifreeze admixtures-related accidents searched from January 1, 2005 to December 31, 2012 were included in this study. The information about the accidents provided by the KOSHA came from the claimed cases for workers’ compensation. The KOSHA has investigated the claimed cases for occupational accidents and diseases requested by the Korea Labor Welfare Corporation, which is responsible for workers’ compensation. The information about the claimed cases included the injured person, the nature and degree of the injuries, the workplace, the circumstances of the accident or the dangerous occurrence, mortality, etc. Medical records of patients admitted to our ED and the data of the KOSHA were reviewed. The diagnosis of methemoglobinemia was based on clinical symptoms and MetHb level, measured by the CO-Oximeter test.
Results Clinical summary of ED cases A total of six patients presented to the ED and were reviewed. Clinical summary of patients with methemoglobinemia after unintentional ingestion of antifreeze admixtures containing sodium nitrite at the construction sites is presented in Table 1. In six victims admitted, three incidents involving unintentional ingestion of antifreeze admixtures containing sodium nitrite at the construction sites were identified. All patients were male workers with ages ranging from 48 to 67 years. Two patients cooked ramen noodles using boiled antifreeze admixtures in the kettle and ate them with other 5 workers
(Incident 1 presented in Table 2). Three patients cooked the instant cup noodles using boiled antifreeze admixtures in the water bottle and ate them with other 5 workers (Incident 2 presented in Table 2). One patient drank one mouthful of antifreeze admixtures contained in the water bottle. After unintentional ingestion of antifreeze admixtures, all patients had symptoms and signs of methemoglobinemia. COOximeter test was performed at about 131–245 min after ingestion of antifreeze admixtures and initial MetHb levels ranged from 32.4% to 71.5%. Two patients were intubated because of altered mentality and severe respiratory distress. All patients received infusions of methylene blue for methemoglobinemia and recovered without sequelae. Clinical summary of cases reported to the KOSHA From the data of the KOSHA, six incidents that involved 27 victims were identified (Table 2). Of 27 victims, five were included in the ED cases. For the first three incidents, 24 victims ate the cup noodles using water including antifreeze admixtures. For the latter three incidents, three victims drank antifreeze admixtures that were contained in the wine bottle or water bottle. For all incidents, antifreeze admixtures were not contained in their original containers and all new containers did not have a new label. All victims mistook antifreeze admixtures for water; four of them died but there is not sufficient information to determine if they had adequate medical treatment.
Discussion We identified that unintentional ingestion of antifreeze admixtures containing sodium nitrite due to the lack of awareness at the construction sites can cause life-threatening methemoglobinemia. Also the present study highlights
Table 1. Clinical summary of emergency department patients with methemoglobinemia after unintentional ingestion of antifreeze admixtures containing sodium nitrite at the construction sites. Interval* Initial MetHb (minute) (%)
Incident
Sex
Age
1
Male
67
182
32.4
1
Male
60
210
71.4
2
Male
66
131
45.4
2
Male
48
191
71.5
2
Male
51
215
68.3
3
Male
66
245
36.0
Clinical features
Intubation
Antidote treatment (Methylene blue)
Outcome
Alert, cyanotic, shortness of breath, headache, dizziness, nausea and vomiting Drowsy, cyanotic, shortness of breath, headache, dizziness, nausea and vomiting Alert, cyanotic, shortness of breath, headache, dizziness, nausea and vomiting Alert, cyanotic, shortness of breath, headache, dizziness, nausea and vomiting Alert, cyanotic, shortness of breath, headache, dizziness, nausea and vomiting Drowsy, cyanotic, shortness of breath, headache, dizziness, nausea and vomiting
No
Single dose (2 mg/kg) infusion
Alive
Yes
Two doses (2 mg/kg ⫹ 2 mg/kg) infusion
Alive
No
Single dose (2 mg/kg) infusion
Alive
No
Single dose (2 mg/kg) infusion
Alive
No
Single dose (2 mg/kg) infusion
Alive
Yes
Two doses (2 mg/kg ⫹ 2 mg/kg) infusion
Alive
MetHb; methemoglobin. *Interval means time from ingestion to measurement of initial serum methemoglobin level by CO-Oximeter test. Copyright © Informa Healthcare USA, Inc. 2014
46
C. H. Sohn et al.
Table 2. Summary of recent incidents involving unintentional ingestion of antifreeze admixtures containing sodium nitrite at the construction sites from the Korea Occupational Safety and Health Agency (KOSHA).* Incident
Date
Incident description
1
December 23, 2012
2
November 29, 2012
3
January 8, 2012
4
December 19, 2007
5
December 20, 2006
6
January 1, 2005
Seven workers developed shortness of breath, LOC after eating the cup noodle using water including antifreeze admixtures at the construction site. Of these workers, two were included in our ED cases. Seven workers developed shortness of breath, LOC after eating the cup noodle and drinking coffee using water including antifreeze admixtures at the construction site. Of these workers, three were included in our ED cases. Ten workers developed shortness of breath, LOC after eating the cup noodle using water including antifreeze admixtures at the construction site. Of these workers, a 60-year-old male worker died during treatment in the hospital. A 60-year-old male worker died during treatment in the hospital after drinking antifreeze admixtures that were contained in the wine bottle, mistaken for wine at the construction site. A 57-year-old female worker drank antifreeze admixtures contained in the water bottle at the construction site and died during treatment in the hospital. A 48-year-old male worker died during treatment in the hospital after drinking antifreeze admixtures mistaken for a beverage at the construction site.
LOC; loss of consciousness, ED; Emergency Department. *Incident 3 listed in Table 1 is not included here.
the need to store and label potentially hazardous materials properly to avoid unintentional ingestion at the construction sites. Acquired methemoglobinemia is most commonly caused by ingestion of an oxidizing agent such as nitrites.2 We identified the active ingredient contained in antifreeze admixtures from two manufacturers. The active ingredient of antifreeze admixtures that patients had ingested was sodium nitrite and there were no other active ingredients. About 20–50% of sodium nitrite was contained in antifreeze admixtures. Thus, we concluded that methemoglobinemia was caused by sodium nitrite contained in antifreeze admixtures. Generally, symptoms of methemoglobinemia correlate with MetHb level in healthy patients. In our cases, MetHb level ranged from 32.4% to 71.5%. All patients had shortness of breath, headache, dizziness, nausea, vomiting, and cyanosis. Two patients deteriorated to drowsy mentality and had severe respiratory distress requiring intubation for airway protection and adequate ventilation. The mainstay of the treatment of acquired methemoglobinemia is identification and withdrawal of the offending agent.14 Methylene blue is the treatment of choice in severe cases of methemoglobinemia.15 All of patients recovered from methemoglobinemia after receiving one (2 mg/kg) or two doses infusion of methylene blue. To drastically improve workplace safety and minimize the severity of those that might occur, hazardous chemicals should be stored in their original labeled containers. Also for hazardous chemicals transferred to new containers, each new container must be labeled with the full chemical name, a warning describing the material’s main hazardous property.16 In Korea, antifreeze admixtures stored in their original container are instructed to be added to the concrete with the mixing water as a last component of the concrete mix. However, antifreeze admixtures are often premixed in water for the efficiency of work. Because antifreeze admixtures are colorless and odorless, they may be mistaken for water. For all incidents discussed in the present study, antifreeze admixtures were not contained in their original
containers and all new containers did not have a new label. Furthermore, because antifreeze admixtures were contained in a kettle, a beverage bottle, or a water bottle, workers mistook antifreeze admixtures for water. These findings suggest that almost all accidents taking antifreeze admixtures at the construction sites can be prevented through storing and labeling potentially hazardous materials properly. According to our data and the data of the KOSHA, at least seven incidents involving unintentional ingestion of antifreeze admixtures containing sodium nitrite at the construction sites have occurred recently in Korea. Among these incidents, a total of 28 victims were involved and four of them died. Our study has several limitations. First, this study was limited by its retrospective design, with all of the potential errors inherent to this type of study. Second, we did not confirm the sodium nitrite through a qualitative or a quantitative toxicologic analysis because these analyses are unavailable in our institution. However, there were many literature reports on sodium nitrite-induced methemoglobinemia and we identified that the main component of antifreeze admixtures ingested by the victims was 20–40% sodium nitrite. Thus the diagnosis of methemoglobinemia caused by sodium nitrite contained in antifreeze admixtures is considered appropriate. Third, we analyzed only patients who presented to our ED and cases from the KOSHA. Thus, it would be difficult to apply our results to all patients with methemoglobinemia caused by antifreeze admixtures. Fourth, we didn’t have data on the annual incidence of work-related methemoglobinemia among the construction workers in Korea.
Conclusions Unintentional ingestion of antifreeze admixtures containing sodium nitrite due to the lack of awareness at the construction sites can cause life-threatening methemoglobinemia. There is a need to store and label potentially hazardous materials properly to avoid unintentional ingestion at the construction sites. Clinical Toxicology vol. 52 no. 1 2014
Methemoglobinemia due to antifreeze admixtures 47
Declaration of interest The authors report no declarations of interest. The authors alone are responsible for the content and writing of the paper.
References 1. Mansouri A, Lurie AA. Concise review: methemoglobinemia. Am J Hematol 1993; 42:7–12. 2. Wright RO, Lewander WJ, Woolf AD. Methemoglobinemia: etiology, pharmacology, and clinical management. Ann Emerg Med 1999; 34:646–656. 3. Charles J, Korhonen ERC. Antifreeze admixtures for cold weather concreting. Concr Int 1991; 13:38–41. 4. Ellis M, Hiss Y, Shenkman L. Fatal methemoglobinemia caused by inadvertent contamination of a laxative solution with sodium nitrite. Isr J Med Sci 1992; 28:289–291. 5. Bradberry SM, Gazzard B, Vale JA. Methemoglobinemia caused by the accidental contamination of drinking water with sodium nitrite. J Toxicol Clin Toxicol 1994; 32:173–178. 6. Freeman L, Wolford RW. Methemoglobinemia secondary to cleaning solution ingestion. The J Emerg Med 1996; 14:599–601.
Copyright © Informa Healthcare USA, Inc. 2014
7. Saito T, Takeichi S, Yukawa N, Osawa M. Fatal methemoglobinemia caused by liniment solutions containing sodium nitrite. J Forensic Sci 1996; 41:169–171. 8. Centers for Disease Control and Prevention. Methemoglobinemia following unintentional ingestion of sodium nitrite – New York, 2002. Morb Mortal Wkly Rep 2002; 51:639–642. 9. Su YF, Lu LH, Hsu TH, Chang SL, Lin RT. Successful treatment of methemoglobinemia in an elderly couple with severe cyanosis: two case reports. J Med Case Rep 2012; 6:290. 10. Rozenfeld IH. Methemoglobinemia resulting from the absorption of sodium nitrite; report of a case. JAMA 1953; 152:706. 11. Singley TL III. Secondary methemoglobinemia due to the adulteration of fish with sodium nitrite. Ann Intern Med 1962; 57:800–803. 12. Schindler D. Severe methemoglobinemia of a nurse after poisoning with the corrosion preventing agent sodium nitrite used in the disinfection of instruments. Med Welt 1968; 9:447–448. 13. Korea Occupational Safety and Health Agency. http://www.english koshaorkr/english/maindo. Accessed on 23 February 2013. 14. Skold A, Cosco DL, Klein R. Methemoglobinemia: pathogenesis, diagnosis, and management. South Med J 2011; 104:757–761. 15. Groeper K, Katcher K, Tobias JD. Anesthetic management of a patient with methemoglobinemia. South Med J 2003; 96:504–509. 16. University of Arizona. Risk Mangement Services – Chemical Management Best Practices. http://www.riskarizonaedu/healthandsafety/ chemicalmgmtbestpractices/indexshtml. Accessed on 4 March 2013.
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CRITICAL CARE
Life-threatening methemoglobinemia after unintentional ingestion of antifreeze admixtures containing sodium nitrite in the construction sites C. H. SOHN, D. W. SEO, S. M. RYOO, J. H. LEE, W. Y. KIM, K. S. LIM, and B. J. OH Department of Emergency Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea
Context. Construction workers are exposed to a wide variety of health hazards such as poisoning at the construction sites. Various forms of poisoning incidents in construction workers have been reported. However, studies on methemoglobinemia caused by unintentional ingestion of antifreeze admixtures containing sodium nitrite at the construction sites have not been reported yet. Objective. The aim of this study was to evaluate life-threatening methemoglobinemia after unintentional ingestion of antifreeze admixtures containing sodium nitrite at the construction sites and describe similar incidents involving ingestion of antifreeze admixtures in Korea. Materials and methods. Retrospective observational case series study on patients with methemoglobinemia after unintentional ingestion of antifreeze admixtures containing sodium nitrite admitted to the emergency department (ED) from January 1, 2010 to December 31, 2012 and cases reported to the Korea Occupational Safety and Health Agency (KOSHA) was performed. Results. Six victims were admitted to our ED. They had methemoglobin levels ranging from 32.4% to 71.5% and all of them recovered after receiving one (2 mg/kg) or two doses infusion of methylene blue. From the data of the KOSHA, six incidents that caused 27 victims were identified. Of 27 victims, five were included in the ED cases. For all incidents, antifreeze admixtures were not contained in their original containers and all new containers did not have a new label. All workers mistook antifreeze admixtures for water. Among the 28 victims included in this study, four died. Conclusion. Unintentional ingestion of antifreeze admixtures containing sodium nitrite at the construction sites can cause life-threatening methemoglobinemia. There is a need to store and label potentially hazardous materials properly to avoid unintentional ingestion at the construction sites. Keywords Methemoglobinemia; Sodium nitrite; Antifreeze admixtures; Construction sites
Introduction
sodium nitrite at the construction sites have not been reported yet. Recently in South Korea, workers at the construction sites died after eating the instant cup noodle using boiled antifreeze admixtures mistaken for water.13 The aim of this study was to evaluate the clinical characteristics and outcomes of patients who were diagnosed with methemoglobinemia after unintentional ingestion of antifreeze admixtures containing sodium nitrite at the construction sites and describe similar incidents involving ingestion of antifreeze admixtures in Korea.
Methemoglobinemia occurs when hemoglobin is oxidized to form methemoglobin (MetHb), in which the iron in the heme group is in the Fe3⫹ (ferric) state, not the Fe2⫹ (ferrous) of normal hemoglobin, rendering it incapable of oxygen transport and leading to tissue hypoxia in severe cases.1 The most common cause of methemoglobinemia is ingestion of an oxidizing agent such as nitrites.2 Sodium nitrites are common antifreeze compounds used for cold weather concreting.3 Because antifreeze admixtures containing sodium nitrite are colorless and odorless, these substances can be mistaken for water. Many cases of methemoglobinemia caused by sodium nitrites in a variety of situations have been reported.4–12 However, to date, studies on methemoglobinemia caused by unintentional ingestion of antifreeze admixtures containing
Methods This retrospective observational case series study was performed at the emergency department (ED) of Asan Medical Center, a tertiary care university-affiliated hospital in Seoul, Korea. The study patients were initially identified via a hospital computer database system using a hospital discharge diagnosis with methemoglobinemia from January 1, 2010 to December 31, 2012. Finally, patients with methemoglobinemia associated with incidents involving unintentional ingestion of antifreeze admixtures were included. This study was approved by the ethics committee of our institution.
Received 7 May 2013; accepted 3 November 2013. Address correspondence to Dong Woo Seo, MD, Department of Emergency Medicine, University of Ulsan College of Medicine, Asan Medical Center, Asanbyeongwon-gil 86, Sonpa-gu, Seoul 138-736, Republic of Korea. Tel: ⫹ 82-2-3010-3350. Fax: ⫹ 82-2-3010-3360. E-mail: [email protected]
44
Methemoglobinemia due to antifreeze admixtures 45 And to enhance the knowledge of this pattern of poisoning occurring at the construction sites, the authors identified further incidents in Korea by using the keyword ‘antifreeze in Korean) on the website of the admixture’ ( Korea Occupational Safety and Health Agency (KOSHA).13 All antifreeze admixtures-related accidents searched from January 1, 2005 to December 31, 2012 were included in this study. The information about the accidents provided by the KOSHA came from the claimed cases for workers’ compensation. The KOSHA has investigated the claimed cases for occupational accidents and diseases requested by the Korea Labor Welfare Corporation, which is responsible for workers’ compensation. The information about the claimed cases included the injured person, the nature and degree of the injuries, the workplace, the circumstances of the accident or the dangerous occurrence, mortality, etc. Medical records of patients admitted to our ED and the data of the KOSHA were reviewed. The diagnosis of methemoglobinemia was based on clinical symptoms and MetHb level, measured by the CO-Oximeter test.
Results Clinical summary of ED cases A total of six patients presented to the ED and were reviewed. Clinical summary of patients with methemoglobinemia after unintentional ingestion of antifreeze admixtures containing sodium nitrite at the construction sites is presented in Table 1. In six victims admitted, three incidents involving unintentional ingestion of antifreeze admixtures containing sodium nitrite at the construction sites were identified. All patients were male workers with ages ranging from 48 to 67 years. Two patients cooked ramen noodles using boiled antifreeze admixtures in the kettle and ate them with other 5 workers
(Incident 1 presented in Table 2). Three patients cooked the instant cup noodles using boiled antifreeze admixtures in the water bottle and ate them with other 5 workers (Incident 2 presented in Table 2). One patient drank one mouthful of antifreeze admixtures contained in the water bottle. After unintentional ingestion of antifreeze admixtures, all patients had symptoms and signs of methemoglobinemia. COOximeter test was performed at about 131–245 min after ingestion of antifreeze admixtures and initial MetHb levels ranged from 32.4% to 71.5%. Two patients were intubated because of altered mentality and severe respiratory distress. All patients received infusions of methylene blue for methemoglobinemia and recovered without sequelae. Clinical summary of cases reported to the KOSHA From the data of the KOSHA, six incidents that involved 27 victims were identified (Table 2). Of 27 victims, five were included in the ED cases. For the first three incidents, 24 victims ate the cup noodles using water including antifreeze admixtures. For the latter three incidents, three victims drank antifreeze admixtures that were contained in the wine bottle or water bottle. For all incidents, antifreeze admixtures were not contained in their original containers and all new containers did not have a new label. All victims mistook antifreeze admixtures for water; four of them died but there is not sufficient information to determine if they had adequate medical treatment.
Discussion We identified that unintentional ingestion of antifreeze admixtures containing sodium nitrite due to the lack of awareness at the construction sites can cause life-threatening methemoglobinemia. Also the present study highlights
Table 1. Clinical summary of emergency department patients with methemoglobinemia after unintentional ingestion of antifreeze admixtures containing sodium nitrite at the construction sites. Interval* Initial MetHb (minute) (%)
Incident
Sex
Age
1
Male
67
182
32.4
1
Male
60
210
71.4
2
Male
66
131
45.4
2
Male
48
191
71.5
2
Male
51
215
68.3
3
Male
66
245
36.0
Clinical features
Intubation
Antidote treatment (Methylene blue)
Outcome
Alert, cyanotic, shortness of breath, headache, dizziness, nausea and vomiting Drowsy, cyanotic, shortness of breath, headache, dizziness, nausea and vomiting Alert, cyanotic, shortness of breath, headache, dizziness, nausea and vomiting Alert, cyanotic, shortness of breath, headache, dizziness, nausea and vomiting Alert, cyanotic, shortness of breath, headache, dizziness, nausea and vomiting Drowsy, cyanotic, shortness of breath, headache, dizziness, nausea and vomiting
No
Single dose (2 mg/kg) infusion
Alive
Yes
Two doses (2 mg/kg ⫹ 2 mg/kg) infusion
Alive
No
Single dose (2 mg/kg) infusion
Alive
No
Single dose (2 mg/kg) infusion
Alive
No
Single dose (2 mg/kg) infusion
Alive
Yes
Two doses (2 mg/kg ⫹ 2 mg/kg) infusion
Alive
MetHb; methemoglobin. *Interval means time from ingestion to measurement of initial serum methemoglobin level by CO-Oximeter test. Copyright © Informa Healthcare USA, Inc. 2014
46
C. H. Sohn et al.
Table 2. Summary of recent incidents involving unintentional ingestion of antifreeze admixtures containing sodium nitrite at the construction sites from the Korea Occupational Safety and Health Agency (KOSHA).* Incident
Date
Incident description
1
December 23, 2012
2
November 29, 2012
3
January 8, 2012
4
December 19, 2007
5
December 20, 2006
6
January 1, 2005
Seven workers developed shortness of breath, LOC after eating the cup noodle using water including antifreeze admixtures at the construction site. Of these workers, two were included in our ED cases. Seven workers developed shortness of breath, LOC after eating the cup noodle and drinking coffee using water including antifreeze admixtures at the construction site. Of these workers, three were included in our ED cases. Ten workers developed shortness of breath, LOC after eating the cup noodle using water including antifreeze admixtures at the construction site. Of these workers, a 60-year-old male worker died during treatment in the hospital. A 60-year-old male worker died during treatment in the hospital after drinking antifreeze admixtures that were contained in the wine bottle, mistaken for wine at the construction site. A 57-year-old female worker drank antifreeze admixtures contained in the water bottle at the construction site and died during treatment in the hospital. A 48-year-old male worker died during treatment in the hospital after drinking antifreeze admixtures mistaken for a beverage at the construction site.
LOC; loss of consciousness, ED; Emergency Department. *Incident 3 listed in Table 1 is not included here.
the need to store and label potentially hazardous materials properly to avoid unintentional ingestion at the construction sites. Acquired methemoglobinemia is most commonly caused by ingestion of an oxidizing agent such as nitrites.2 We identified the active ingredient contained in antifreeze admixtures from two manufacturers. The active ingredient of antifreeze admixtures that patients had ingested was sodium nitrite and there were no other active ingredients. About 20–50% of sodium nitrite was contained in antifreeze admixtures. Thus, we concluded that methemoglobinemia was caused by sodium nitrite contained in antifreeze admixtures. Generally, symptoms of methemoglobinemia correlate with MetHb level in healthy patients. In our cases, MetHb level ranged from 32.4% to 71.5%. All patients had shortness of breath, headache, dizziness, nausea, vomiting, and cyanosis. Two patients deteriorated to drowsy mentality and had severe respiratory distress requiring intubation for airway protection and adequate ventilation. The mainstay of the treatment of acquired methemoglobinemia is identification and withdrawal of the offending agent.14 Methylene blue is the treatment of choice in severe cases of methemoglobinemia.15 All of patients recovered from methemoglobinemia after receiving one (2 mg/kg) or two doses infusion of methylene blue. To drastically improve workplace safety and minimize the severity of those that might occur, hazardous chemicals should be stored in their original labeled containers. Also for hazardous chemicals transferred to new containers, each new container must be labeled with the full chemical name, a warning describing the material’s main hazardous property.16 In Korea, antifreeze admixtures stored in their original container are instructed to be added to the concrete with the mixing water as a last component of the concrete mix. However, antifreeze admixtures are often premixed in water for the efficiency of work. Because antifreeze admixtures are colorless and odorless, they may be mistaken for water. For all incidents discussed in the present study, antifreeze admixtures were not contained in their original
containers and all new containers did not have a new label. Furthermore, because antifreeze admixtures were contained in a kettle, a beverage bottle, or a water bottle, workers mistook antifreeze admixtures for water. These findings suggest that almost all accidents taking antifreeze admixtures at the construction sites can be prevented through storing and labeling potentially hazardous materials properly. According to our data and the data of the KOSHA, at least seven incidents involving unintentional ingestion of antifreeze admixtures containing sodium nitrite at the construction sites have occurred recently in Korea. Among these incidents, a total of 28 victims were involved and four of them died. Our study has several limitations. First, this study was limited by its retrospective design, with all of the potential errors inherent to this type of study. Second, we did not confirm the sodium nitrite through a qualitative or a quantitative toxicologic analysis because these analyses are unavailable in our institution. However, there were many literature reports on sodium nitrite-induced methemoglobinemia and we identified that the main component of antifreeze admixtures ingested by the victims was 20–40% sodium nitrite. Thus the diagnosis of methemoglobinemia caused by sodium nitrite contained in antifreeze admixtures is considered appropriate. Third, we analyzed only patients who presented to our ED and cases from the KOSHA. Thus, it would be difficult to apply our results to all patients with methemoglobinemia caused by antifreeze admixtures. Fourth, we didn’t have data on the annual incidence of work-related methemoglobinemia among the construction workers in Korea.
Conclusions Unintentional ingestion of antifreeze admixtures containing sodium nitrite due to the lack of awareness at the construction sites can cause life-threatening methemoglobinemia. There is a need to store and label potentially hazardous materials properly to avoid unintentional ingestion at the construction sites. Clinical Toxicology vol. 52 no. 1 2014
Methemoglobinemia due to antifreeze admixtures 47
Declaration of interest The authors report no declarations of interest. The authors alone are responsible for the content and writing of the paper.
References 1. Mansouri A, Lurie AA. Concise review: methemoglobinemia. Am J Hematol 1993; 42:7–12. 2. Wright RO, Lewander WJ, Woolf AD. Methemoglobinemia: etiology, pharmacology, and clinical management. Ann Emerg Med 1999; 34:646–656. 3. Charles J, Korhonen ERC. Antifreeze admixtures for cold weather concreting. Concr Int 1991; 13:38–41. 4. Ellis M, Hiss Y, Shenkman L. Fatal methemoglobinemia caused by inadvertent contamination of a laxative solution with sodium nitrite. Isr J Med Sci 1992; 28:289–291. 5. Bradberry SM, Gazzard B, Vale JA. Methemoglobinemia caused by the accidental contamination of drinking water with sodium nitrite. J Toxicol Clin Toxicol 1994; 32:173–178. 6. Freeman L, Wolford RW. Methemoglobinemia secondary to cleaning solution ingestion. The J Emerg Med 1996; 14:599–601.
Copyright © Informa Healthcare USA, Inc. 2014
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