@2024 Afarand., IRAN

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ISSN: 1027-1457    Scientific Journal of Forensic Medicine 2019;25(3):151-156

Background
… [1]. After alcohol and some medications, carbon monoxide poisoning is probably the most common type of poisoning that a forensic pathologist typically deals with [2].
Previous Studies
According to the Iranian Legal Medicine Statistical Yearbook, 836 cases of gas poisoning deaths in 2016 (about 1.5% of total deaths and approximately 2.3% of abnormal deaths) have been referred to Legal medical centers through Iran [3]. According to Iranian civil law, derived from the Islam, it is necessary to determine the time of death of each death with relative to his / her kinship and the priority and delay in occurrence in mass events to determine heirs and inheritance and inheritance share, so, legal inquiries will be made from legal medicine. ... [4]. There have been few studies on poisoning in Iran, but the majority has been limited to examining the overall frequency and demographic components of the poisoning, and none has approached the death of victims in terms of the order of deaths
Aim(s)
The purpose of this study was to determine the order of deaths and its diagnostic criteria in victims of carbon monoxide poisoning.
Research type
This research was a cross-sectional and retrospective descriptive study.
Research society, place and time
In this study, all records of deaths due to carbon monoxide poisoning, referred to legal medicine centers of Tehran province during 2012-2016 were assessed.
Sampling method and number
Among the existing documents, death records related to the events with more than one victim were collected and their information, including variables included in the checklist were recorded.
Used devices&materials
The checklist was designed to address the various medical, forensic and legal aspects that influence the determination of the order of deaths in victims of carbon monoxide poisoning. The studied variables included type, cause, location and time of the accident, the number and gender of the victims and their transfer to the treatment center, the existence of kinship between the victims of the accident and the kinship category (according to Iranian civil law), complaints about the death of the victims of the accident, how to examine the corpses and perform laboratory sampling, request for a lawsuit, the presence legal medicine experts at the scene, existence of inquiry for determining the time of death (the first and the last) and the related respond. The diagnostic criteria were the request for a medical commission and other judicial inquiries regarding the death of each of the victims (other than the order of deaths) that were obtained from the victims’ documents available in the Legal medical centers in Tehran, including corpse examination and autopsy reports, reports of the toxicology and pathology laboratories, relatives' statement forms, hospital reports, photos of clinical and criminal records letters of judicial inquiry and responses. The collection of the records and the completion of the checklists were fully supervised by the researchers, so that all needed information was collected. Data were analyzed by SPSS 19 software.
Findings by Text
Of the 846 deaths due to carbon monoxide poisoning, in 674 cases referred to Legal Medicine Centers in Tehran during 2012-16, 131 cases (35.8%) had more than one victim that considering the population of Tehran at the time of the study, their prevalence was estimated approximately 0.2 per 100,000 person (2 per million). Of these, 120 cases (91.6%) were accidental and the reason for 11 cases was unknown. The main cause of accidents was carbon monoxide emissions due to incomplete combustion (93.1%), followed by fire (4.6%) and winter and autumn were the most frequent seasons with 58.1% and 23.7% rates, respectively.The male-to-female ratio was approximately 3: 2. In 8.4% of these incidents, the victims had been transferred to a medical center and in 29.8% of the cases, the relatives had complained about the death of at least one victim in documents. In 49 cases (37.4%) other than carboxyhemoglobin examination, toxicological and pathological samples had been sent to the laboratory (67.3% and 14.3%, respectively). Except for 2 cases (1.5%), Legal Medicine experts were not present at the scene of the accident, and only 15 cases (11.5%) showed asking for lawsuit. Homes and workplaces were the most common places for accidents. The studied cases had a total of 303 victims and the majority of them (95 cases) were recorded with two victims. In 62.6% of the cases, all victims' bodies had been examined by visual examination and in 28.2% by autopsy. In 65.6% of the events, a kinship was found between all or some of the victims of the accident, and in 82.6% of the accidents among relatives, they were first-degree relatives based on the Article 862 of the Iranian Civil Law. In 23.3% of the accidents among relatives (15.3% of all accidents with more than one victim), the judicial authority inquired about the order of deaths, of which 70.0% was relative and 15.0% was definite. In response to the aforementioned judicial inquiries, the age factor of the victims (alone) was the commonest criterion for determining the order of deaths, followed by the physical conditions of the accident location (mainly the distance from where the body was located to the source of carbon monoxide production) (Table 1). In 10.0% of the cases, the request for a medical commission had reported by the judicial authority to determine the order of the victims' deaths, whereas in 3.1% of the cases, it had reported for other reasons than the order of deaths.
Main comparison to the similar studies
Of the 674 deaths due to carbon monoxide poisoning in Tehran province during the years 2012 to 2016, 131 cases (35.8%) had more than one victim (approximate male to female ratio of 3 to 2), of which 91.6% were incidental, occurring at home (72.6%) and in winter (58.1%). These results were in good agreement with those of other researchers [5–9]. Transferring the victims to the treatment center was reported in 8.4% of the incidents, which was in contrast to the results of Wilson et al. (probably due to the differences in factors associated with the studied population) [11] In the present study, 120 cases (91.6%) were accidental, of which 93.1% were caused by incomplete combustion and 4.6% were caused by fire. These results were not inconsistent with the findings of other studies [9, 11, 12], probably due to the differences in the structure of the studied communities.
Suggestions
Conducting studies on determining the criteria to detect the order of deaths and using appropriate methods to obtain it regarding mass accidents are suggested to promote the experts’ opinions on judicial inquiries.
Limitations
Examination of corpses by different physicians, different examination methods and recording their findings, and the lack of relevant and valid documentation in a document related to an event were some of the limitations of this study.
Conclusions
Forensic practitioners are needed to make inquiries about the order of victims' deaths in incidents, and also consider the role of individual and environmental factors and their impact on accelerating the process of death.
Acknowledgments
The authors are thankful to Dr. Qadipasha, the Director of Legal Medicine Organization of Tehran and Mr. Dr. Salari, the Chief of Performance Assessment and Complaints Division of Tehran Legal Medicine Organization.
Conflict of interest
None declared.
Ethical Permissions
The research protocol was approved by the Ethics Committee on Forensic Medicine of the Iranian Forensic Medicine Organization (Approval code: IR.LMO.REC.1396.46).
Funding Sources
This study was funded by the Medical Research Organization of Iran.

TABLES and CHARTS

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