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Treatment of acute chlorine gas inhalation with nebulized sodium bicarbonate
The Journal of Emergency Medicine, Vol. 8, pp. 327329,
Printed in the USA
1990
. Copyright
0 1990 Pergamon Press plc
Toxkology
TREATMENT OF ACUTE CHLORINE GAS INHALATION WITH NEBULIZED SODIUM BICARBONATE Paul J. Vinsel, DO,cpt, MC Reprint address:
Emergency Paul J. Vinsel,
Medicine Residency, Darnall Army Community Hospital, Ft. Hood, Texas Department of Emergency Medicine, Darnall Army Community Hospital, Ft. Hood, TX 76544
DO,
vomiting, dyspnea, and a burning sensation in the throat and substemal region (7). Major exposure may lead to a severe pneumonitis, pulmonary edema, and respiratory compromise (3). Traditional management of acute chlorine gas inhalation is mainly supportive. Rest, humidified oxygen, and treatment of cough with codeine have been recommended in mild cases of exposure (7). Intermittent positive pressure breathing (IPPB) and corticosteroids may be considered in severe injury (4,7,8). In a 1976 review of toxic gas inhalation, Done suggested the use of a nebulized solution of 5% sodium bicarbonate for chlorine gas inhalation (6). This treatment is not generally recommended due to a lack of clinical trials (5,9, 10). In fact, no case reports of the treatment of acute chlorine gas inhalation with nebulized sodium bicarbonate exist. We present 3 patients who were exposed to chlorine gas in the same accident. All were successfully treated with nebulized sodium bicarbonate.
0 Abstract - Three male patients, 19 to 20 years old, were exposed to chlorine gas secondary to a leak in the chlorination system of an indoor pool. AU of the patients were symptomatic with cough, chest pain, and shortness of breath. Physical examinations, arterial blood gases, and chest radiographs were normal. AU patients were given a nebulixed solution of 3.75% sodium bicarbonate which resulted in prompt relief of their symptoms. None of the patients suffered from prolonged symptomatology. Thii therapy appears to be useful in treating chlorine gas inhalation; however, it cannot be routinely recommended without prospective clinical studies evahutting its efficacy and safety. i-J Keywords - inhalation injury; chlorine; sodium bicarbonate
INTRODUCTION Chlorine gas inhalation injury is often the result of an industrial accident which may lead to numerous simultaneous casualties (l-4). Smaller numbers of patients are injured from inhalation of chlorine used in the treatment of swimming pools (5) or when household bleach containing hypochlorite is mixed with strong acids, releasing chlorine gas (6). Chlorine gas acts as an irritant to mucous membranes, causing rhinorrhea, lacrimation, severe cough, nausea,
CASE REPORT Three male patients, ages 19 to 20, were exposed to chlorine gas due to a leak in the chlorination system of an indoor pool where they worked as lifeguards. Within minutes of exposure, all three developed a burning sensation in the throat and chest, severe cough, shortness of breath, and nausea. The patients presented to the emergency department 10 minutes after exposure. Vital signs on arrival were normal, except that all of
The opinions or assertions presented do not necessarily reflect those of the Department of the Army or the Department of Defense.
FQXEIVED: 20 September ACCEPTED: 22 September
1988; 1989
FINAL SUBMISSIONRECEIVED:20
327
August 1989
0736-4679&O $3.00 + .OO
Paul J. Vinsel the patients were tachypneic with respiratory rates ranging from 32 to 50. Each patient was experiencing severe paroxysms of cough. Physical examinations, including mucous membranes and lung fields, were normal except for one patient with mild erythema and edema of his nasal mucosa. Arterial blood gases were sampled on each patient and were normal without hypoxemia or hypocapnea, despite the patients being tachypneic with respiratory rates ranging from 30 to 50. PA and lateral chest radiographs were normal. Each patient was given 4 cc of a 3.75% sodium bicarbonate solution (made by diluting 2 cc of the standard 7 5% intravenous sodium bicarbonate solution with 2 cc of normal saline) inhaled using a hand-held mininebulizer. This resulted in complete cessation of the patients’ cough and shortness of breath. Vital signs after treatment were normal with the respiratory rates decreased to 20 to 22. The patients were discharged without further treatment and instructed to return if symptoms recurred. Six weeks later the patients were contacted by telephone. One had remained free of symptoms, and two had had a mild cough lasting 4 to 6 hours after exposure. DISCUSSION Inhaled chlorine gas acts as a mucous membrane irritant. The primary mechanism of injury is through the release of nascent oxygen when chlorine gas comes into contact with water on the mucous membranes of the patient (7,ll). The chemical equation for this reaction is: Cl, + HzG $2HCl + 0-. The oxygen free radicals as well as hydrochloric acid are all directly toxic to respiratory mucosa. The duration and severity of symptoms varies directly with the concentration of chlorine gas and the duration of exposure (2). The threshold limit of exposure to chlorine gas is one part per million, and this can usually be tolerated for up to 8 hours (7). Short exposure at 3 to 5 PPM is well tolerated; however, prolonged exposure at this level will produce symptoms. Severe exposure to chlorine gas may result in pulmonary edema and death. Postmortem findings reveal grossly congested and edematous lungs (11). Areas of normal lung parenchyma surrounded by areas of edema and pneumonic exudates are seen microscopically. In less severe exposure the patient may present with cough, chest pain, muscle weakness, headache, and a feeling of oropharyngeal dryness. Physical examination is usually normal, with decreased breath sounds being the most frequent finding (2). Bronchospasm is often present, but may be detectable only with early pulmonary function studies (7). ABGs may be normal, or may
reveal hypoxia or metabolic acidosis in severe cases (3,4). Initial chest x-ray may demonstrate signs of pulmonary edema in severe exposure but is usually normal (3). Pulmonary function studies have indicated both obstructive and restrictive disease following chlorine gas exposure (l-3,12). There is no conclusive evidence that these effects are long term. Patients may complain of exercise intolerance for several days following exposure, even if they are asymptomatic at rest (7). However, the patients in this report denied any decrease in their exercise tolerance following treatment. Treatment of acute chlorine gas exposure begins with removing the patient from the offending environment. Humidified oxygen and rest are advocated for the patient with mild exposure. Symptomatic relief of the cough may be accomplished with an antitussive containing codeine (7). Bronchoconstriction may be treated with inhaled B-agonists, subcutaneous epinephrine, or intravenous aminophylline (4,7). Patients with pulmonary edema require more aggressive therapy. IPPB may be useful in these patients (4,7,8). Corticosteroids may be of some benefit in the patient with pulmonary edema, but clinical studies evaluating their efficacy are lacking (7). In 1977 Chester et al. reported a case involving two sisters exposed to chlorine gas in the same accident. One was hospitalized and treated with corticosteroids while the other was discharged from the emergency department without corticosteroids. Both patients had abnormal pulmonary function studies following the exposure. Those of the patient treated with corticosteroids returned to normal within 24 months while the untreated sibling continued with abnormal pulmonary function 55 months after exposure. Done advocates the use of 5% sodium bicarbonate solution administered by nebulizer (6). This is thought to work by neutralizing the hydrochloric acid that develops when chlorine gas comes into contact with water. Goldfrank cautions against this treatment due to a possible exothermic reaction when bicarbonate mixes with hydrochloric acid (10). However, the dilute concentration of sodium bicarbonate delivered by this method may not produce this reaction (9). There have been no studies on the effect of nebulized sodium bicarbonate on lung tissue. The three patients in this report had a short duration of exposure to chlorine and presented to the emergency department with mild symptoms. Their physical examinations and ABGs were essentially normal. All patients had immediate improvement of their symptoms after the nebulized sodium bicarbonate treatment, were symptomfree within 24 hours, and had no residual exercise intolerance. Unfortunately, pulmonary spirometry to determine if there was objective evidence of improve-
329
Chlorine Gas Inhalation
ment was not performed on these patients. None of the patients presented with or developed more severe manifestations of toxicity such as pulmonary edema or respiratory compromise. It is unknown if nebulized sodium bicarbonate would be helpful in the treatment of severe toxicity. SUMMARY Chlorine gas is an irritant to mucous membranes. Upon inhalation, most patients will complain of cough, chest
pain, shortness of breath, and burning sensation of the throat. We report on the relief of these symptoms after sodium bicarbonate nebulized therapy. This therapy cannot be routinely recommended due to a lack of clinical studies relating to its efficacy and safety.
Acknowledgment - The author wishes to thank Dr. Daniel Dire for his assistance in proofreading
this manuscript.
REFERENCES 1. Charan NB, Lakshminarayan S, Myers GC, Smith DD. Effects of accidental chlorine inhalation on pulmonary function. West J Med. 1985;143:333-6. 2. Kowitz TA, Reba RC, Parker RT, Spicer WS. Effects of chlorine gas upon respiratory function. Arch Environ Health. 1967;14: 545-58. 3. Kaufman J, Burkons D. Clinical, roentgenologic, and physiologic effects of acute chlorine exposure. Arch Environ Health. 1971;23: 29-34. 4. Hedges JR, Morrissey WL. Acute chlorine gas exposure. J Amer Co11 Emerg Phys. 1979;8:59-63. 5. Wood BR, Colombo JR, Benson BE. Chlorine inhalation toxicity from vapors generated by swimming pool chlorinator tablets. Pediatrics. 1987;79:427-30. 6. Done AK. The toxic emergency, it’s a gas. Emerg Med. 1976: 305-14.
7. Kramer CG. Chlorine. J Occup Med. 1967;9:193-6. 8. Chester EH, Kaimal PJ, Payne CB, Kohn PM. Pulmonary injury following exposure to chlorine gas: possible beneficial effects of steroid treatment. Chest. 1977;72:247-50. 9. Done AK. Chlorine gas. Poisindexo Substance Identification, Micromedex, vol. 57. Micromedex Inc., Denver, CO; 1987. 10. Goldfrank LR, Bresnitz EA. Toxic inhalations. In: Goldfrank LR, ed. Goldfrank’s toxicologic emergencies. 3rd edition. East Norwalk, Connecticut. Prentice-Hall; 1986:651-61. 11. Adelson L, Kaufman J. Fatal chlorine poisoning: report of two cases with clinicopathologic correlation. Amer J Clin Path. 197 1;56: 430-42. 12. Ploysongsang Y, Beach BC, DiLisio RE. Pulmonary function changes after acute inhalation of chlorine gas. South Med J. 1982:75:236.
Printed in the USA
1990
. Copyright
0 1990 Pergamon Press plc
Toxkology
TREATMENT OF ACUTE CHLORINE GAS INHALATION WITH NEBULIZED SODIUM BICARBONATE Paul J. Vinsel, DO,cpt, MC Reprint address:
Emergency Paul J. Vinsel,
Medicine Residency, Darnall Army Community Hospital, Ft. Hood, Texas Department of Emergency Medicine, Darnall Army Community Hospital, Ft. Hood, TX 76544
DO,
vomiting, dyspnea, and a burning sensation in the throat and substemal region (7). Major exposure may lead to a severe pneumonitis, pulmonary edema, and respiratory compromise (3). Traditional management of acute chlorine gas inhalation is mainly supportive. Rest, humidified oxygen, and treatment of cough with codeine have been recommended in mild cases of exposure (7). Intermittent positive pressure breathing (IPPB) and corticosteroids may be considered in severe injury (4,7,8). In a 1976 review of toxic gas inhalation, Done suggested the use of a nebulized solution of 5% sodium bicarbonate for chlorine gas inhalation (6). This treatment is not generally recommended due to a lack of clinical trials (5,9, 10). In fact, no case reports of the treatment of acute chlorine gas inhalation with nebulized sodium bicarbonate exist. We present 3 patients who were exposed to chlorine gas in the same accident. All were successfully treated with nebulized sodium bicarbonate.
0 Abstract - Three male patients, 19 to 20 years old, were exposed to chlorine gas secondary to a leak in the chlorination system of an indoor pool. AU of the patients were symptomatic with cough, chest pain, and shortness of breath. Physical examinations, arterial blood gases, and chest radiographs were normal. AU patients were given a nebulixed solution of 3.75% sodium bicarbonate which resulted in prompt relief of their symptoms. None of the patients suffered from prolonged symptomatology. Thii therapy appears to be useful in treating chlorine gas inhalation; however, it cannot be routinely recommended without prospective clinical studies evahutting its efficacy and safety. i-J Keywords - inhalation injury; chlorine; sodium bicarbonate
INTRODUCTION Chlorine gas inhalation injury is often the result of an industrial accident which may lead to numerous simultaneous casualties (l-4). Smaller numbers of patients are injured from inhalation of chlorine used in the treatment of swimming pools (5) or when household bleach containing hypochlorite is mixed with strong acids, releasing chlorine gas (6). Chlorine gas acts as an irritant to mucous membranes, causing rhinorrhea, lacrimation, severe cough, nausea,
CASE REPORT Three male patients, ages 19 to 20, were exposed to chlorine gas due to a leak in the chlorination system of an indoor pool where they worked as lifeguards. Within minutes of exposure, all three developed a burning sensation in the throat and chest, severe cough, shortness of breath, and nausea. The patients presented to the emergency department 10 minutes after exposure. Vital signs on arrival were normal, except that all of
The opinions or assertions presented do not necessarily reflect those of the Department of the Army or the Department of Defense.
FQXEIVED: 20 September ACCEPTED: 22 September
1988; 1989
FINAL SUBMISSIONRECEIVED:20
327
August 1989
0736-4679&O $3.00 + .OO
Paul J. Vinsel the patients were tachypneic with respiratory rates ranging from 32 to 50. Each patient was experiencing severe paroxysms of cough. Physical examinations, including mucous membranes and lung fields, were normal except for one patient with mild erythema and edema of his nasal mucosa. Arterial blood gases were sampled on each patient and were normal without hypoxemia or hypocapnea, despite the patients being tachypneic with respiratory rates ranging from 30 to 50. PA and lateral chest radiographs were normal. Each patient was given 4 cc of a 3.75% sodium bicarbonate solution (made by diluting 2 cc of the standard 7 5% intravenous sodium bicarbonate solution with 2 cc of normal saline) inhaled using a hand-held mininebulizer. This resulted in complete cessation of the patients’ cough and shortness of breath. Vital signs after treatment were normal with the respiratory rates decreased to 20 to 22. The patients were discharged without further treatment and instructed to return if symptoms recurred. Six weeks later the patients were contacted by telephone. One had remained free of symptoms, and two had had a mild cough lasting 4 to 6 hours after exposure. DISCUSSION Inhaled chlorine gas acts as a mucous membrane irritant. The primary mechanism of injury is through the release of nascent oxygen when chlorine gas comes into contact with water on the mucous membranes of the patient (7,ll). The chemical equation for this reaction is: Cl, + HzG $2HCl + 0-. The oxygen free radicals as well as hydrochloric acid are all directly toxic to respiratory mucosa. The duration and severity of symptoms varies directly with the concentration of chlorine gas and the duration of exposure (2). The threshold limit of exposure to chlorine gas is one part per million, and this can usually be tolerated for up to 8 hours (7). Short exposure at 3 to 5 PPM is well tolerated; however, prolonged exposure at this level will produce symptoms. Severe exposure to chlorine gas may result in pulmonary edema and death. Postmortem findings reveal grossly congested and edematous lungs (11). Areas of normal lung parenchyma surrounded by areas of edema and pneumonic exudates are seen microscopically. In less severe exposure the patient may present with cough, chest pain, muscle weakness, headache, and a feeling of oropharyngeal dryness. Physical examination is usually normal, with decreased breath sounds being the most frequent finding (2). Bronchospasm is often present, but may be detectable only with early pulmonary function studies (7). ABGs may be normal, or may
reveal hypoxia or metabolic acidosis in severe cases (3,4). Initial chest x-ray may demonstrate signs of pulmonary edema in severe exposure but is usually normal (3). Pulmonary function studies have indicated both obstructive and restrictive disease following chlorine gas exposure (l-3,12). There is no conclusive evidence that these effects are long term. Patients may complain of exercise intolerance for several days following exposure, even if they are asymptomatic at rest (7). However, the patients in this report denied any decrease in their exercise tolerance following treatment. Treatment of acute chlorine gas exposure begins with removing the patient from the offending environment. Humidified oxygen and rest are advocated for the patient with mild exposure. Symptomatic relief of the cough may be accomplished with an antitussive containing codeine (7). Bronchoconstriction may be treated with inhaled B-agonists, subcutaneous epinephrine, or intravenous aminophylline (4,7). Patients with pulmonary edema require more aggressive therapy. IPPB may be useful in these patients (4,7,8). Corticosteroids may be of some benefit in the patient with pulmonary edema, but clinical studies evaluating their efficacy are lacking (7). In 1977 Chester et al. reported a case involving two sisters exposed to chlorine gas in the same accident. One was hospitalized and treated with corticosteroids while the other was discharged from the emergency department without corticosteroids. Both patients had abnormal pulmonary function studies following the exposure. Those of the patient treated with corticosteroids returned to normal within 24 months while the untreated sibling continued with abnormal pulmonary function 55 months after exposure. Done advocates the use of 5% sodium bicarbonate solution administered by nebulizer (6). This is thought to work by neutralizing the hydrochloric acid that develops when chlorine gas comes into contact with water. Goldfrank cautions against this treatment due to a possible exothermic reaction when bicarbonate mixes with hydrochloric acid (10). However, the dilute concentration of sodium bicarbonate delivered by this method may not produce this reaction (9). There have been no studies on the effect of nebulized sodium bicarbonate on lung tissue. The three patients in this report had a short duration of exposure to chlorine and presented to the emergency department with mild symptoms. Their physical examinations and ABGs were essentially normal. All patients had immediate improvement of their symptoms after the nebulized sodium bicarbonate treatment, were symptomfree within 24 hours, and had no residual exercise intolerance. Unfortunately, pulmonary spirometry to determine if there was objective evidence of improve-
329
Chlorine Gas Inhalation
ment was not performed on these patients. None of the patients presented with or developed more severe manifestations of toxicity such as pulmonary edema or respiratory compromise. It is unknown if nebulized sodium bicarbonate would be helpful in the treatment of severe toxicity. SUMMARY Chlorine gas is an irritant to mucous membranes. Upon inhalation, most patients will complain of cough, chest
pain, shortness of breath, and burning sensation of the throat. We report on the relief of these symptoms after sodium bicarbonate nebulized therapy. This therapy cannot be routinely recommended due to a lack of clinical studies relating to its efficacy and safety.
Acknowledgment - The author wishes to thank Dr. Daniel Dire for his assistance in proofreading
this manuscript.
REFERENCES 1. Charan NB, Lakshminarayan S, Myers GC, Smith DD. Effects of accidental chlorine inhalation on pulmonary function. West J Med. 1985;143:333-6. 2. Kowitz TA, Reba RC, Parker RT, Spicer WS. Effects of chlorine gas upon respiratory function. Arch Environ Health. 1967;14: 545-58. 3. Kaufman J, Burkons D. Clinical, roentgenologic, and physiologic effects of acute chlorine exposure. Arch Environ Health. 1971;23: 29-34. 4. Hedges JR, Morrissey WL. Acute chlorine gas exposure. J Amer Co11 Emerg Phys. 1979;8:59-63. 5. Wood BR, Colombo JR, Benson BE. Chlorine inhalation toxicity from vapors generated by swimming pool chlorinator tablets. Pediatrics. 1987;79:427-30. 6. Done AK. The toxic emergency, it’s a gas. Emerg Med. 1976: 305-14.
7. Kramer CG. Chlorine. J Occup Med. 1967;9:193-6. 8. Chester EH, Kaimal PJ, Payne CB, Kohn PM. Pulmonary injury following exposure to chlorine gas: possible beneficial effects of steroid treatment. Chest. 1977;72:247-50. 9. Done AK. Chlorine gas. Poisindexo Substance Identification, Micromedex, vol. 57. Micromedex Inc., Denver, CO; 1987. 10. Goldfrank LR, Bresnitz EA. Toxic inhalations. In: Goldfrank LR, ed. Goldfrank’s toxicologic emergencies. 3rd edition. East Norwalk, Connecticut. Prentice-Hall; 1986:651-61. 11. Adelson L, Kaufman J. Fatal chlorine poisoning: report of two cases with clinicopathologic correlation. Amer J Clin Path. 197 1;56: 430-42. 12. Ploysongsang Y, Beach BC, DiLisio RE. Pulmonary function changes after acute inhalation of chlorine gas. South Med J. 1982:75:236.