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A fatal case of septic tank gas poisoning: Critical care challenges

Journal of Anesthesia & Critical Care: Open Access
A Fatal Case of Septic Tank Gas Poisoning: Critical Care
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Septic tanks [1] are enclosed areas made for accumulation
of decomposed domestic wastes, sewerage and its resultant
gases. Sewer gases can be both toxic and non-toxic. Its major
component is Methane [2], which can be extremely toxic in high
concentrations. Sewer gas is a mixture of Hydrogen Sulphide,
Ammonia, Carbon-dioxide, Nitrogen dioxide, Sulphur dioxide
and sometimes, even carbon monoxide. The concentration of
these components differs with the time, sewage composition,
temperature and pH of the contents. Hydrogen sulphide [3] can
be poisonous even in small concentrations in the form of irritation
of the eyes, shortness of breath and incessant cough. Exposure to
higher concentrations can be rapidly fatal. We hereby present a
fatal case of septic tank gas poisoning in a young patient and the
critical care challenges faced.
Case Report
A 24 years old, ASA grade 1, male patient was brought to the
emergency in an unconscious state. There was history of the
patient jumping into a septic tank to save a child who accidentally
fell into the septic tank. As soon as he could evacuate out the child,
he became unconscious and was trapped inside the septic tank
out by neighbours. There was no past history of any illnesses or
allergies or hospitalizations. On examination, the patient was
comatose, hemodynamically stable, with an oxygen saturation of
80% which improved to 90% with supplemental oxygen. In view
of poor GCS (Glasgow Coma Scale) and oxygen desaturation, the
patient was intubated with an 8.5mm cuffed endotracheal tube
and put on assist controlled mode of mechanical ventilation.
       
improved and became 99% on an FiO2 of 80%. His bilateral pupils
were mid-dilated and sluggishly reacting to light. There was no
response to deep painful stimuli. Invasive monitoring with central
venous catheter and arterial line were instituted. Ryles tube
was inserted and nasogastric feeds were started to prevent gut
bacterial translocation. Patient was kept adequately warm and
hypothermia preventive measures were instituted. On the second
day in the intensive care unit, the patient developed decerebrate
posturing. His ABG (arterial blood gas analysis) showed moderate
compensated metabolic acidosis. There was a fall in his urine
output and he also demonstrated spikes of intermittent fever.
There was no improvement in the GCS. All standard supportive
therapies were instituted. Intensive monitoring was continued.
         
Surgical tracheostomy was done due to failure to wean and for
tracheobronchial toilet. His neuro logical condition further
worsened and the patient did not demonstrate any respiratory
efforts of his own. The computed tomographic (CT) scan of
the patient`s brain was suggestive of hypoxic damage. He
also developed hypotension requiring inotropic support and
further oxygen desaturation requiring 100% inspired oxygen
concentration on the fourth day. Finally, the patient succumbed to
septic tank gas poisoning and developed cardiorespiratory arrest
Septic tanks are quite common in residential and industrial
areas to cater to sewage wastes. Natural decomposition and
mixture of sewage leads to production of sewage gases. These
gases can be toxic if inhaled in high concentrations or for a
prolonged period of time. Septic tank gases contain methane,
hydrogen sulphide (H2S), carbon dioxide, sulphur dioxide,
ammonia, nitrogen dioxide and traces of carbon monoxide.
Hydrogen sulphide has a characteristic smell of rotten eggs,
Volume 6 Issue 3 - 2016
Assistant Professor, Anesthesia and Intensive care, Dr Ram
Manohar Lohia Hospital and PGIMER, India
*Corresponding author: Uma Hariharan, Fellowship
Oncoanesthesia, Assistant Professor, Department of
Anesthesiology and Intensive care, Dr. Ram Manohar Lohia
Hospital and Post Graduate Institute of Medical Education
and Research, Central Health Services, BH 41, East Shalimar
Bagh, Delhi 110088, New Delhi, India, Tel: +919811271093;
Received: October 17, 2016 | Published: November 30,
Case Report
J Anesth Crit Care Open Access 2016, 6(3): 00228
Deaths due to poisoning continue to haunt the medical practice. Poisoning
could be due to accidental, suicidal or homicidal reasons. Certain poisons do not
have antidotes and can be rapidly fatal. The victims generally succumb either
due to the deleterious effects of the toxic substance per-se or due to secondary
phenomenon or multi-organ failure. Septic tanks are dangerous as they contain
a variety of sewer gases which can be highly toxic when inhaled and result in
various complications, including death. We hereby report a fatal case of accidental
poisoning due to septic tank gases in a young patient and the associated critical
care challenges.
Keywords: Septic tank; Poisoning; Sewer gases; Toxic; Hydrogen Sulfide;
Methane; Fatal
Citation: Hariharan U, Bhasin N, Mittal V, Sood R (2016) A Fatal Case of Septic Tank Gas Poisoning: Critical Care Challenges. J Anesth Crit Care Open
Access 6(3): 00228. DOI: 10.15406/jaccoa.2016.06.00228
A Fatal Case of Septic Tank Gas Poisoning: Critical Care Challenges 2/2
©2016 Hariharan et al.
as a warning signal for sewer gas leakage. It is a colourless gas,
 
concentrations of hydrogen sulphide can cause irritation of the
eyes, sore throat, dyspnea and cough. Prolonged exposure can even
cause pulmonary edema, headache and dizziness [4]. Exposure to
levels > 100ppm (parts per million) can be dangerous as it causes
olfactory fatigue and the smell becomes undetectable. Exposure
to higher concentrations (>300 ppm), results in rapid loss of
consciousness and death. Even a single breath of a concentration
higher than 1000 ppm can cause immediate collapse (‘knock-
down”) and death. The toxicity of H2S is due to inhibition of
oxidative phosphorylation and cytochrome oxidase resulting in
reduction in cellular ATP (adenosine tri-phosphate). Inhalation
leads to a multitude of respiratory complications like organizing
pneumonia and adult respiratory distress syndrome (ARDS).
Exposure to high concentrations of methane can be dangerous as
it reduces percentage of oxygen in the air and causes hypoxia [5].
Methane gas inhalation can cause asphyxia, loss of consciousness
and pneumonitis.
Our patient had entered the septic tank to save a child
accidentally trapped inside it. After evacuating the child, the
patient became unconscious probably due to exposure to high
        
minutes, before he was evacuated by neighbours. He was
brought in a comatose state to the emergency where he was
managed according to standard protocol and given all supportive
treatments. The patient would have already suffered hypoxic
           
antidote to septic tank gas poisoning. Hypoxic injury to brain and
other organs is usually irreversible and hence the patient could
not be saved.
There is paucity of literature on the diagnosis and
management of septic tank gas poisoning. In several areas,
especially developing nations, there are no standard guidelines or
protocols for designing, construction, cleaning and maintenance
of septic tanks. Casualties [6] occurring due to septic tanks may
not even be reported, which may be responsible for the lack of
accurate statistical data on the health hazards caused by them. All
septic tanks should have a display board highlighting the dos and
don’ts as well as the possible hazards due to sewer gases. Only
authorized and trained personnel wearing personal protective
gear should be allowed inside the septic tanks. All necessary
precautions should be taken by the septic tank workers to
prevent themselves and others from getting trapped inside the
septic tanks. The government agencies should formulate special
rules and regulations for safe use and maintenance of septic
tanks. Measures for quick evacuation must be ensured in the
event of any accident. As health professionals, our aim must be
to provide adequate ventilation and oxygenation to the patient,
prevent secondary brain injury, maintain hemodynamic stability
and circumvent multi-organ damage. The general principles
of critical care management consist of administering 100%
oxygen, endotracheal intubation to protect the airway, adequate
ventilation to prevent hypercarbia, ensuring normothermia,
instituting invasive monitoring, regular GCS charting, maintaining
adequate mean arterial pressure and urine output. Hyperbaric
oxygen therapy [7] may be useful in some hemodynamically
       
supportive therapy, amyl nitrite and sodium nitrite inhalation
    
is evacuated early.
Septic tanks continue to be health hazards as they produce
sewer gases which can be toxic to human beings and also cause
greenhouse effect. Septic tank gas poisoning can be fatal if
inhaled in high concentrations or for prolonged periods. Proper
precautions should be taken before entering septic tanks and
all people must be educated about the health hazards of sewer
gases. Hypoxic damage to the vital body organs can be extremely
severe poisoning cases.
1. Whorton J (2001) “The insidious foe”– sewer gas”. West J Med
175(6): 427-428.
2. Jo JY, Kwon YS, Lee JW, Park JS, Rho BH, et al. (2013) Acute Respiratory
Distress due to Methane Inhalation. Tuberc Respir Dis (Seoul) 74(3):
3.     
adult male. Ann Saudi Med 30(1): 76-80.
4. 
to sewer gas exposure. Am J Emerg Med 26(4): 518.e5-7.
5. Terazawa K, Takatori T, Tomii S, Nakano K (1985) Methane asphyxia:
coal mine accident investigation of distribution of gas. Am J Forensic
Med Pathol 6(3): 211-214.
6. Knight LD, Presnell SE (2005) Death by sewer gas: Case report of a
double fatality and review of the literature. Am J Forensic Med Pathol
26(2): 181-185.
7. Belley R, Bernard N, Cote M, Paquet F, Poitras J (2005) Hyperbaric
oxygen therapy in the management of two cases of hydrogen
sulphide toxicity from liquid manure. CJEM 7(4): 257-261.
... Inhalation of gases: A combination of factors such as sealed tanks (no vent pipe), long de-sludging cycles, and use of chemicals for toilet cleaning lead to the accumulation of gases in the OSS. Studies have shown that 'the concentration of gases varies based on factors such as the frequency of de-sludging intervals, sludge composition, temperature and pH' (Hariharan et al., 2016). While a more thorough testing and evaluation is necessary, several newspaper reports seem to indicate that inhalation of gases could cause deatheither directly or indirectly (for examples of these newspaper reports, see Indiatimes 5 and NewsClick 6 ). ...
Full-text available
Safety of sanitation workers remains an often-ignored aspect in Fecal Sludge Management. While shifting workers from manual to mechanical means of de-sludging remains a priority, this paper highlights that there are a number of safety issues, including exposure to sludge, faced by sanitation workers, even in a mechanised context, where de-sludging trucks are utilised to provide de-sludging services. Based on a detailed analysis of observation of stakeholders and extensive process documentation (of de-sludging process), and expert interviews, the study identified three key safety concerns: inhalation of harmful gases, contact with sludge, and physical injury, and determined the underlying cause for the same, using a systems thinking approach. These causes are varied including behaviours and practices by households such as non-compliance of septic tank construction to design standards, irregular cleaning, improper disposal of inappropriate items in toilets; inappropriate or inadequate design of decanting stations, tools and equipment, and inadequate awareness and knowledge among all stakeholders. Using the hierarchy of controls framework, a set of measures are described to increase the safety of workers. These proposed interventions go beyond the provision of Personal Protective Equipment (PPE), and range from behaviour change campaigns, improvements in decanting stations, better access to appropriately designed tools. The study highlights the need to place emphasis on eliminating, substituting and controlling the hazards as necessary steps for PPE to be relevant. Finally, the paper places the issue of occupational safety within the larger context of the informal nature of de-sludging occupation and the overall vulnerability of workers. It posits that this makes safety more complicated to address as several factors need to be taken into account, and actions are required by multiple sets of actors.
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Hydrogen sulfide (H 2 S) is responsible for many incidents of occupational toxic exposure, especially in the petroleum industry. The clinical effects of H 2 S depend on its concentration and the duration of exposure. H 2 S is immediately fatal when concentrations are over 500-1000 parts per million (ppm) but exposure to lower concentrations, such as 10-500 ppm, can cause various respiratory symptoms that range from rhinitis to acute respiratory failure. H 2 S may also affect multiple organs, causing temporary or permanent derangements in the nervous, cardiovascular, renal, hepatic, and hematological systems. We present a case of occupational exposure to H 2 S leading to multi-organ involvement, acute respiratory failure, organizing pneumonia, and shock resembling acute sepsis. The patient also developed mild obstructive and restrictive pulmonary disease and peripheral neuropathy.
Full-text available
Inhalation of toxic gases can lead to pneumonitis. It has been known that methane gas intoxication causes loss of consciousness or asphyxia. There is, however, a paucity of information about acute pulmonary toxicity from methane gas inhalation. A 21-year-old man was presented with respiratory distress after an accidental exposure to methane gas for one minute. He came in with a drowsy mentality and hypoxemia. Mechanical ventilation was applied immediately. The patient's symptoms and chest radiographic findings were consistent with acute pneumonitis. He recovered spontaneously and was discharged after 5 days without other specific treatment. His pulmonary function test, 4 days after methane gas exposure, revealed a restrictive ventilatory defect. In conclusion, acute pulmonary injury can occur with a restrictive ventilator defect after a short exposure to methane gas. The lung injury was spontaneously resolved without any significant sequela.
Hydrogen sulfide (H(2)S) is responsible for many incidents of occupational toxic exposure, especially in the petroleum industry. The clinical effects of H(2)S depend on its concentration and the duration of exposure. H(2)S is immediately fatal when concentrations are over 500-1000 parts per million (ppm) but exposure to lower concentrations, such as 10-500 ppm, can cause various respiratory symptoms that range from rhinitis to acute respiratory failure. H(2)S may also affect multiple organs, causing temporary or permanent derangements in the nervous, cardiovascular, renal, hepatic, and hematological systems. We present a case of occupational exposure to H(2)S leading to multi-organ involvement, acute respiratory failure, organizing pneumonia, and shock resembling acute sepsis. The patient also developed mild obstructive and restrictive pulmonary disease and peripheral neuropathy.
Death from asphyxia due to substitution of air by methane gas may occur in coal mine by gas outburst. In such a case, it is required to determine methane gas contents from cadaveric blood and tissues for diagnosing cause of death and estimating conditions of the accident. The methane concentration in blood and tissue samples of 22 male victims by a gas outburst accident was measured by gas chromatography. The level of methane in the cardiac blood was in the range of 6.8-26.8 microliters/g. As a model of gas outburst in coal mine, rats were exposed experimentally to various concentrations of methane. Their course of death and methane distribution in the bodies were observed. From these findings, diagnostic criteria for asphyxia from substitution of air by methane are also discussed.
Hydrogen sulfide (H2S), the toxic gas associated with the smell of "rotten eggs," is an important cause of work-related sudden death. The gas is particularly insidious due to the unpredictability of its presence and concentration and its neurotoxicity at relatively low concentrations, causing olfactory nerve paralysis and loss of the warning odor. We report a double fatality involving 2 surveyors working near a man-hole, who fell into the sewer and died due to sudden exposure to hydrogen sulfide gas. Key historical, physical, and toxicologic findings are described. Additionally, we present a discussion of the clinical presentations and differential diagnosis, mechanism of injury, metabolism and toxicology, incidence, and scene and safety concerns in fatal hydrogen sulfide exposures.
Hydrogen sulfide is a potent lethal gas. Supportive care, nitrite therapy and hyperbaric oxygen are the treatment modalities reported in the literature in cases of hydrogen sulfide exposure. We describe an industrial exposure in which 6 workers inhaled high concentrations of hydrogen sulfide when they entered a closed spreader tank partially filled with liquid swine manure. Five of the 6 lost consciousness, and 2 were agitated and poorly responsive on arrival to the emergency department despite having already received high-flow oxygen for nearly 1 hour. These 2 patients received nitrite therapy followed by orotracheal intubation and hyperbaric oxygen. All patients were discharged home without sequelae after short stays in hospital. The emergency management of hydrogen sulfide exposure is briefly reviewed.
Hydrogen sulfide toxicity is a known risk for individuals working in the petroleum, sewer, maritime, and mining industries. Concern regarding exposure has led to the development of safety precautions and treatment guidelines. The US government imposes safety measures including self-contained breathing masks and exposure time limits to hydrogen sulfide gas. Current treatment methods, however, are not strongly supported by research. Acute exposure to hydrogen sulfide gas still poses a significant life threat. In this report, we discuss a case of a sewer worker exposed to deadly concentrations of hydrogen sulfide. Safety precautions and treatment options available to those exposed to high doses of hydrogen sulfide gas are explored.