Abstract
Background
Fire victims are at risk of inhaling potentially toxic gases contained within smoke. Carbon monoxide gas (CO) is the most significant and may contribute to morbidity and mortality of patients. Early detection of CO poisoning by measuring exhaled CO in correlation to the clinical parameters suggestive of CO poisoning in mild to moderate burn injuries among fire victims was our aim.
Methods
Case-control study involving 40 fire victims presenting with flame burn injuries within 24 h who were assessed for CO poisoning. Control group involved 40 healthy nonsmoker individuals. Exhaled CO level was measured using a CO Check Pro Device, which was correlated to clinical parameters suggestive of CO poisoning in addition to elevated lactate level.
Results
The median exhaled CO level was significantly higher in cases compared to controls (4.5 ppm vs. 1.5 ppm, p < 0.001). Among fire victims, 37.5 % had mild CO poisoning. Significant positive correlations were found between exhaled CO levels and lactate levels (r = 0.54, p < 0.001), duration of flame exposure (r = 0.59, p < 0.001), and crowding index (r = 0.49, p = 0.009).
Discussion
Exhaled carbon monoxide levels is a valuable diagnostic tool for the early detection of CO poisoning among fire victims with mild to moderate burn injuries. The correlation between elevated exhaled CO levels and clinical symptoms, alongside serum lactate level, supports their use as reliable indicator of CO exposure in fire victims, thereby optimizing emergency response strategies.
Keywords: Carbon monoxide poisoning, Fire victims, Exhaled carbon monoxide, Clinical parameters, Burn injuries
African relevance
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Fire victims are at risk of inhaling potentially toxic gases contained within the smoke. Little attention to theses toxic gases compared to the burn injury among the fire victims provoked the importance of highlighting this problem among African population who have higher proportion of fire related death and injuries.
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This study attempt to early detect carbon monoxide poisoning among fire victims using exhaled carbon monoxide levels and clinical parameters as valuable diagnostic tools specially when carboxyhemoglobin level is unavailable in some emergency hospitals in Africa.
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This study impact the patients by optimizing emergency response strategies in Africa through a more available diagnostic tools.
Introduction
A WHO report from 2018 states that every year, between 200,000 and 300,000 people die from burns caused by fire, with low- and middle-income African and Asian nations bearing a disproportionate share of these deaths [1]. Systemic inhalational toxicities, including Carbon monoxide (CO) being linked to early deaths especially in large-scale fires [2].
There are no distinct manifestations in CO poisoning patients making diagnosis difficult, although blood carboxyhemoglobin (COHB) levels are the gold standard in diagnosing patients with CO poisoning, the clinical presentation frequently does not correlate with the COHB level. There may be no symptoms in mild toxicity and clinical improvement in the patient's state does not always correlate with COHB clearance [3]. Symptoms that may be associated with mild toxicity may include fatigue, headache, anxiety or depression, malaise, nausea, and vomiting. Moderate toxicity might present as confusion, and convulsions. Severe toxicity can lead to ataxia, loss of consciousness, myocardial infarction, cerebral infarction, and even death [4].
Deliberate screening for probable CO inhalational poisoning in burn patients is desirable because CO is recognized as one of the most common causes of sudden deaths in fire accidents [2]. These diagnostic challenges cause substantial complications in patients during acute and chronic periods. When an early diagnosis is missed, CO can have delayed and chronic damage [5].
Clinical parameters, such as the Glasgow Coma Scale (GCS) and laboratory markers such as arterial blood gas (ABG) [6] and lactate level are prognostic tools for evaluating the severity and outcome of CO-related illness [7].
Although blood carboxyhemoglobin measurement is the gold standard diagnostic test for CO poisoning, it is not readily available in abundance and/or in the required time for most hospitals [8]. Measuring exhaled CO concentration provides a non-invasive and rapid method for assessing CO exposure [9]. Exhaled CO is a biomarker that has been extensively studied for its diagnostic and prognostic value in various clinical settings [10].
For these reasons, this study aimed to assess features suggestive of CO inhalational poisoning among mild to moderate burn-injured fire victims compared to exhaled CO level for early detection of CO poisoning.
Methods
Study design and population
This case-control study included two groups. The first group involved 40 non-smoker fire victims, including adults and pediatric patients, who were able to conduct the exhaled carbon monoxide (eCO) test and arrived at the Emergency Department (ED) within 24 h of sustaining mild to moderate flame-burn injuries. Patients with mild to moderate burns lasting longer than 24 h, severe burns, burns around the lips, or any previous medical history were excluded. When subjects arrived at the ED, they were sampled and examined. The second group consisted of 40 healthy nonsmokers from the University Hospital who were matched to the cases based on age, gender, and BMI.
Data collection procedures
All participants provided detailed history, with an emphasis on burn circumstances, fire location (indoor or outdoor, confined or open area), flame exposure length, history of previous carbon monoxide poisoning, and related symptoms. For closed indoor areas, the crowding index was determined by dividing the number of people in the home by the number of rooms, with overcrowding defined as a score of two or higher [11]. The clinical examination included a thorough general assessment, vital signs, and systemic evaluation, with a particular emphasis on the neurological, pulmonary, and cardiac systems.
Burn sites were inspected to determine their degree and severity: first degree (redness and pain), second degree (blistering and edema), and third degree (full-thickness skin loss). Minor burns were defined as first- or second-degree burns that covered less than 15 % of an adult's or 10 % of a child's body. Moderate burns have been designated as second degree, covering more than these percentages, or third degree, covering less than 10 % of the body surface area (BSA). Major burns were third-degree and covered more than 10 % of BSA [12].
The investigations for the cases included arterial blood gases (ABG) for pH, partial pressure of oxygen (PO₂), partial pressure of carbon dioxide (PCO₂), bicarbonate (HCO₃), and lactate levels [13], as well as electrocardiograms (ECG). The CO Check Pro device (MD Diagnostics, UK) was used to monitor carbon monoxide levels in exhaled breath immediately after presenting to the ED and before oxygen therapy. Participants were instructed to hold their breath for 15 s before exhaling slowly and completely within 6 s, with CO measured from the alveolar region of the breath. If the procedure was not complete, it was repeated. The device monitors eCO in parts per million (ppm) with a maximum limit of 99 ppm and calculates equivalent carboxyhemoglobin (%COHb) at concentrations less than 90 ppm [14].
Carbon monoxide poisoning is graded based on COHb levels: mild (>10 %), moderate (>10 % but <20–25 %), and severe (>20–25 %) [15]. Non-smokers have levels above 2 % with symptoms or above 3 % without symptoms, which is diagnostic [16]. In this study, mild CO toxicity was classified as eCO between 13 and 60 ppm (≈2–10 % COHb), and moderate as eCO over 60 ppm (>10 % COHb). No patients exceeded 60 ppm. Mild CO poisoning was identified with eCO levels ≥13 ppm and <60 ppm [14,17], or with clinical symptoms such as headache, dizziness, nausea, drowsiness, tachypnea, dyspnea, palpitations, and diaphoresis, as well as increased lactate [18,19].
Ethical considerations
The study adhered to the Declaration of Helsinki. The Faculty of Medicine Research Ethics Committee (MS-550–2023) approved the study, and all participants provided written informed consent.
Statistical analysis
Based on previous study by Mackutwa et al. (2021) [2] the sample size is determined by the formula for estimation of proportions with finite population correction. The calculated sample size was 40 participants and 40 healthy nonsmoker controls.
Data management and analysis were performed using Statistical Package for Social Sciences (SPSS) vs. 27. In accordance with normality assessments, suitable parametric and non-parametric tests were used to examine the data. The optimal cutoff threshold for eCO in diagnosing CO poisoning was found using ROC curve analysis, P value ≤ 0.05 is considered significance.
Results
All participants were non-smokers and none of them had a history of allergy. All patients were exposed to direct flame and had no previous history of CO poisoning nor history of previous burn injury. GCS in most of the patients were 15, except for 2 patients who were agitated due to their burn pain with GSC of 14. All patients did not receive oxygen before hospital admission, had no clinical signs of dehydration or infection, with normal chest and cardiac examination, normal total leucocytic count and normal ECG findings.
All cases and controls have no previous medical or surgical history, also they were age, sex and BMI matched (p value 0.161, 0.232 & 0.130 respectively). Construction workers represent 27.5 % of the fire victims. Median exhaled CO level was higher among fire victims (4.5 ppm) compared to healthy controls (1.5 ppm). Table 1
Table 1.
Sociodemographic characteristics and Exhaled Carbon monoxide level of the fire victims compared to the control group.
| Control | Fire victims | ||
|---|---|---|---|
| Mean ± SD | Mean ±SD | p value | |
| Age (Years) | 26 ± 6 | 20 ± 13 | 0.161 |
| BMI (Kg/m2) | 23.6 ± 2.6 | 24.2 ± 2.5 | 0.130 |
| n = 40 (%) | n = 40 (%) | ||
| Sex | |||
| Female | 10 (25) | 16 (40) | 0.232 |
| Male | 30 (75) | 24 (60) | |
| Occupation | |||
| Student | 26 (65) | 8 (20) | <0.001 |
| Non workers | 0 (0) | 21 (52.5) | |
| Workers (construction or hospital) | 14 (35) | 11 (27.5) | |
| Median (range | Median (range | ||
| Exhaled CO level (PPM) | 1.5 (0–5) | 4.5 (0–20) | <0.001 |
BMI: Body mass index, CO: carbon monoxide, PPM: part per million.
NA: Not applicable, SD: Standard deviation.
Regarding some clinical characteristics and risk factors for CO poisoning among fire victims, median crowding index was 2 ranging from (1–3) indicating overcrowding, median duration of flame exposure was 8 min ranging from (3–15 min), median surface area of burn injury was 16.5 % ranging from (4–40) %. The median time for hospital arrival was 10 h, ranging from (2–20) hours. In most fire accidents there is more than one victim (62.5 %). The majority of burns were of mild degree (72.5 %), while 27.5 % were of moderate burn injury and about two thirds of cases were of first-degree burn (75 %), first to second degree burn were 7 (17.5 %), second degree burn were 3 (7.5 %). Most of the burn injuries were caused by insidious fire incidents (75 %), while the rest was induced by fire due to gas cylinder expulsion (25 %). The majority of fires occurred in closed spaces (77.5 %) either at home 27 (67.5 %) or work environment 13 (32.5 %).
Greater than half of fire victims have clinical manifestation suggestive of CO toxicity (52.5 %). 37.5 % of patients have mild CO poisoning based on measured exhaled CO level of 13pmm and more, or lactate level more than 1 in addition to clinical manifestations suggestive of CO poisoning. Median serum lactate level was 1.7 ranging from (0.6–7). Median exhaled CO level was 4.5 ranging from (0–20). Non of the patients had moderate or severe CO poisoning based on their eCO level. Table 2
Table 2.
Clinical and laboratory parameters of fire victims.
| n = 40 (%) | ||
|---|---|---|
| Severity of CO poisoning | Mild poisoning | 15 (37.5) |
| No poisoning | 25 (62.5) | |
| Manifestations relevant to CO toxicity | Yes | 21 (52.5) |
| No | 19 (47.5) | |
| Any CNS manifestations | 18 (45) | |
| Dizziness | 10 (25) | |
| Headache | 7 (17.5) | |
| Nausea | 5 (12.5) | |
| Drowsiness | 2 (5) | |
| Level of consciousness (Alert) | 38 (95) | |
| Any respiratory manifestation | 14 (35) | |
| Dyspnea | 10 (25) | |
| Tachypnea | 8 (20) | |
| Any cardiovascular manifestations | 7 (17.5) | |
| Palpitations | 5 (12.5) | |
| Diaphoretic | 4 (10) | |
| Any burn signs | 13 (32.5) | |
| Oropharyngeal hyperemia | 8 (20) | |
| Soot | 6 (15) | |
| Mean ± SD | ||
| Systolic blood pressure | 113 ± 15 | |
| Diastolic blood pressure | 73 ± 8 | |
| Heart rate | 82 ± 10 | |
| Respiratory rate | 15 ± 2 | |
| pH | 7.4 ± 0.04 | |
| PCO2 | 40 ± 2 | |
| HCO3 | 25 ± 2.9 | |
| PO2 | 80 ± 10 | |
| Median (range) | ||
| Oxygen saturation (%) | 97 (95–99) | |
| Lactate | 1.7 (0.6–7) | |
| Exhaled carbon monoxide level (PPM) | 4.5 (0–20) | |
CO: Carbon monoxide, CNS: Central nervous system, PCO2: partial pressure of carbon dioxide, HCO3: bicarbonate, PO2: partial pressure of oxygen, PPM: part per million, SD: Standard deviation.
Classifying fire victims into patients with or without CO poisoning, there was no statistically significant difference between the two groups regarding (age, sex, BMI and occupation). Crowding index, duration of flame exposure, surface area of burn injury and time to hospital arrival were significantly higher in fire victims with CO poisoning compared to patients without.The majority of patients with moderate burn have mild CO poisoning (81.8 %). Table 3
Table 3.
Clinical characteristics and risk factors for CO poisoning among fire victims (with and without CO poisoning).
| Severity of CO | ||||
|---|---|---|---|---|
| No poisoning (n=25) | Mild poisoning (n=15) | |||
| Mean ±SD | Mean ±SD | p value | ||
| Age (Years) | 19 ± 13 | 23 ± 15 | 0.381 | |
| BMI (Kg/m2) | 24.5 ± 2.6 | 23.8 ± 2.4 | 0.366 | |
| N (%) | N (%) | p value | ||
| Sex | Female | 9 (56.3) | 7 (43.8) | 0.740 |
| Male | 16 (66.7) | 8 (33.3) | ||
| Occupation | Student | 7 (87.5) | 1 (12.5) | 0.193 |
| Non workers | 13 (61.9) | 8 (38.1) | ||
| Workers | 5 (45.5) | 6 (54.5) | ||
| Median (range) | Median (range) | p value | ||
| Crowding index (number of people at home/number of rooms) | 2 (1–3) | 3 (2–3) | 0.034 | |
| Duration of flame exposure (mins) | 5 (3–10) | 10 (5–15) | <0.001 | |
| Surface area of burn injury (%) | 15 (4–30) | 25 (10–40) | <0.001 | |
| Time interval to hospital (hours) | 6 (2–20) | 10 (2–16) | 0.046 | |
| N (%) | N (%) | p value | ||
| Number of victims in the accident | One | 9 (60) | 6 (40) | 0.800 |
| More than one | 16 (64) | 9 (36) | ||
| Severity of burn | Mild | 23 (79.3) | 6 (20.7) | <0.001 |
| Moderate | 2 (18.2) | 9 (81.8) | ||
| Burn degree | First | 23 (76.7) | 7 (23.3) | NA |
| First to second | 2 (28.6) | 5 (71.4) | ||
| Second | 0 (0) | 3 (100) | ||
| Source of flame | Insidious fire | 22 (73.3) | 8 (26.7) | 0.024 |
| Gas cylinder expulsion | 3 (30) | 7 (70) | ||
| Site of fire | Home | 16 (59.3) | 11 (40.7) | 0.069 |
| Outdoor | 8 (88.9) | 1 (11.1) | ||
| Work | 1 (25) | 3 (75) | ||
| Site space | Closed | 17 (54.8) | 14 (45.2) | 0.117 |
| Open | 8 (88.9) | 1 (11.1) | ||
BMI: Body mass index, NA: not applicable, P value <0.05 is considered significant.
Lactate and exhaled CO level were significantly higher among patients with mild CO poisoning compared to patients without (p value <0.001). Mild CO poisoning based on measured exhaled CO level of 13pmm and more, or lactate level more than 1mmol/L in addition to clinical manifestations suggestive of CO poisoning previously mentioned. Table 4
Table 4.
Vital signs, blood gases, lactate and carbon monoxide level of fire victims (with and without CO poisoning).
| Severity of CO | |||
|---|---|---|---|
| No poisoning | Mild poisoning | ||
| Mean ± SD | Mean ± SD | p value | |
| Systolic blood pressure | 114 ± 15 | 112 ± 15 | 0.623 |
| Diastolic blood pressure | 74 ± 7 | 73 ± 8 | 0.714 |
| Heart rate | 81 ± 9 | 83 ± 12 | 0.505 |
| Respiratory rate | 15 ± 2 | 15 ± 2 | 0.913 |
| pH | 7.42 ± 0.03 | 7.42 ± 0.05 | 0.666 |
| PO2 | 82 ± 8 | 78 ± 12 | 0.189 |
| PCO2 | 40 ± 2 | 40 ± 2 | 0.773 |
| HCO3 | 25.4 ± 2.9 | 24.4 ± 3 | 0.314 |
| Median (range) | Median (range) | ||
| O2 saturation | 97 (96–99) | 97 (95–98) | 0.251 |
| Lactate | 1.2 (0.6–3.8) | 3 (1.5–7) | <0.001 |
| Exhaled CO level (PPM) | 3 (0–8) | 13 (4–20) | <0.001 |
CO: Carbon monoxide, PCO2: partial pressure of carbon dioxide, HCO3: bicarbonate, PO2: partial pressure of oxygen, PPM: part per million, SD: Standard deviation, P value <0.05 is considered significant.
Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for lactate level (88 %, 94 %, 78 % & 97 % respectively) to detect CO poisoning, with cut-off point more than 2.9. AUC was 0.93, 95 % CI for AUC (0.80–0.99), (p < 0.001).
Regarding the accuracy of clinical manifestations and lactate levels in detecting CO poisoning. When either any clinical manifestation or an elevated lactate level is present, the sensitivity is 100 %. However, the specificity is low at 23 %. The PPV is 25 %, while the NPV is 100 %, resulting in an overall accuracy of 38.5 %. The combination of any clinical manifestation and an elevated lactate level yields a sensitivity of 75 % and a specificity of 56 %. The PPV for this combination is 30 %, and the NPV is 90 %, with an overall accuracy of 60 %.
Correlating exhaled CO to different parameters elaborated a significant positive correlation between exhaled CO level and (lactate level, duration of flame exposure & crowding index). However, there is a significant negative correlation between exhaled CO level and PCO2 (r=−0.3, p value 0.043), despite non-significant correlation for HCO3. Table 5
Table 5.
Correlation between carbon monoxide level with different clinical and laboratory parameters.
| Carbon monoxide level (PPM) | |||
|---|---|---|---|
| Factors | r | p value | Interpretation |
| Lactate level | 0.54 | <0.001 | Significant good positive correlation |
| Duration of flame exposure | 0.59 | <0.001 | Significant good positive correlation |
| Crowding index | 0.49 | 0.009 | Significant fair positive correlation |
| PCO2 | −0.3 | 0.043 | Significant fair negative correlation |
| Age | 0.02 | 0.898 | Non significant correlation |
| Body mass index | 0.1 | 0.362 | Non significant correlation |
| Surface area of burn | 0.3 | 0.059 | Non significant correlation |
| Time to hospital arrival | 0.1 | 0.664 | Non significant correlation |
| Glasgow coma scale | −0.3 | 0.09 | Non significant correlation |
| Systolic blood pressure | 0.1 | 0.691 | Non significant correlation |
| Diastolic blood pressure | 0.01 | 0.935 | Non significant correlation |
| Heart rate | 0.2 | 0.331 | Non significant correlation |
| Respiratory rate | 0.01 | 0.981 | Non significant correlation |
| pH | 0.12 | 0.461 | Non significant correlation |
| PO2 | −0.2 | 0.336 | Non significant correlation |
| Oxygen saturation | −0.2 | 0.232 | Non significant correlation |
| HCO3 | −0.14 | 0.368 | Non significant correlation |
PCO2: partial pressure of carbon dioxide, HCO3: bicarbonate, PO2: partial pressure of oxygen, PPM: part per million, r is the correlation coefficient & it ranges from −1 to +1, p value <0.05 is considered significant.
Discussion
Carbon monoxide (CO) poisoning remains a significant under-recognized threat, despite advancements in medical diagnostics [20]. In emergency settings, the rapid identification and treatment of CO poisoning are critical. Since traditional techniques, like measuring carboxyhemoglobin, require lab analysis and blood samples, which may not always be available, alternative quick alternatives are required [21].
Exhaled CO is a non-invasive, portable way to measure CO exposure, and emerging research supports its utility in monitoring firefighters and screening smokers, although its usage in fire victims has received less attention [17]. This requires a precise and particular diagnostic approach since it is difficult to differentiate the subtle effects of CO poisoning from the anguish caused by the burns itself [22].
To our knowledge, this study is one of the few to investigate the association between lactate level in addition to the clinical features suggestive of CO poisoning and exhaled CO levels as immediate, non-invasive biomarkers for diagnosing CO poisoning in a clinical setting.
A case-control study at a University Hospital ED included 40 fire victims (40 % female, 60 % male) with mild to moderate burns and 40 healthy, age/sex/BMI-matched non-smokers. The majority of burns were mild (72.5 %), first-degree (75 %), caused by insidious fires (75 %), and occurred indoors (67.5 %) or in enclosed places (77.5 %). All had GCS 15, with the exception of two patients (GCS 14) who were agitated owing to burn pain. The median exhaled CO in fire victims was higher than in controls (4.5 vs. 1.5). Mild CO poisoning affected 37.5 %.
To reduce confounding bias and assure reliable eCO level comparisons, the fire victims group is matched to a healthy non-smoker control group based on age, gender, and BMI. Quite similarly, a prospective descriptive investigation at a Kenyan National Hospital examined the clinical evidence of CO poisoning in 80 fire victims with acute flame burn injury. Unlike us, they measured carboxyhemoglobin (SpCO) levels directly with the Masimo SET Radical-57 pulse CO-oximeter. Females accounted for 43.7 % of the cases, while males made up 56.3 %. The bulk (68 %) were between the ages of 18 and 35. The mean %TBSA was 30.9 %, with an average SpCO level of 5.48 %. The most prevalent symptoms were disorientation (28.7 %) and headache (26 %). Only 9 % of the flame burned patients were found to have CO toxicity [2].
CO poisoning is more common in men and the elderly [23,24]. Males may have more exposure through outdoor or high-risk work. Comorbidities among the elderly, particularly cardiovascular disease, increase the risk of mortality even at low exposure [20]. Cultural, occupational, and environmental factors all have an impact on the likelihood of burns and CO injuries, such as males more involved in activities such as working in industries prone to fires, cooking with open flames, or other high-risk occupations [25].
In the current study, The median crowding index among victims was 2 (range 1–3), with flame exposure lasting 8 h (3–15), burn area 16.5 % (4–40 %), and time to hospital arrival 10 h (2–20). Multiple victims were involved in 62.5 % of accidents. The median serum lactate was 1.7 (0.6–7), while the median exhaled CO was 4.5 (0–20). Clinically, 37.5 % had mild CO poisoning, 52.5 % had CO toxicity signs, 45 % had CNS manifestations, 25 % reported dizziness, and 95 % had altered consciousness. CO poisoning patients showed increased crowding indexes, flame exposure, burn area, and hospital arrival times.
Common symptoms of mild-to-moderate CO poisoning include headache, nausea, dizziness, disorientation, exhaustion, chest discomfort, and dyspnea, however, there is a poor association between symptoms and COHb levels [26]. Burn risk is increased by overcrowded dwellings, inadequate fire prevention, and a lack of knowledge [27].
There was a considerable increase in lactate and exhaled CO in mild cases of CO poisoning (p < 0.001). According to previous lactate–COHb correlation studies, both indicators linked with CO exposure and may improve diagnostic accuracy. This dual-marker approach could be particularly beneficial in emergency departments [28].
In the current study, lactate sensitivity was 88 %, specificity 94 %, PPV 78 %, and NPV 97 %, making it more useful for screening and ruling out CO poisoning. Exhaled CO was preferable for confirmation [29]. To prevent confounders (sepsis, dehydration), only mild-moderate burns <24 h were considered. All patients were vitally stable with no clinical or laboratory signs of dehydration or infection.
The current findings revealed that any clinical manifestation or elevated lactate resulted in 100 % sensitivity and NPV, but only 23 % specificity and 25 % PPV. Combining both increased specificity (56 %) and accuracy (60 %) but decreasing sensitivity (75 %) and NPV (90 %). CO levels correlated positively with lactate, flame exposure, and crowding index, but negatively with PCO₂ (r = −0.3, p = 0.043). PO₂ may be normal/increased in CO poisoning as it measures dissolved oxygen, not COHb, but PCO₂ may decrease due to hypoxia-driven hyperventilation or metabolic acidosis compensatory [6]. These findings are consistent with other studies that have noted the difficulties of identifying CO poisoning based solely on symptoms and lactate level [3,5].
Generalizability of the study is limited by the small sample size and non-smoking restrictions. The majority of the victims were male, although the controls were sex-matched. Due to unavailability of blood COHb confirmation, the diagnosis was made based on exhaled CO, clinical characteristics, and lactate, potentially creating bias. The device's top limit of 99 ppm may miss serious poisoning (more than 20–25 % COHb). Larger studies with a broader burn severity representation and validated COHb measurement are required.
Conclusions
The study conclusively demonstrates that exhaled CO levels is a valuable diagnostic tool for the early detection of CO poisoning in patients with mild to moderate burn injuries. The correlation between elevated exhaled CO levels and clinical symptoms, alongside serum lactate level, further supports their use as reliable indicator of CO exposure in fire victims.
Dissemination of results
Results from this research study was shared with staff members of the Emergency Department through thesis presentation discussion.
Author contributions: credit
AK: Data curation, Formal analysis, Investigation, Writing – review & editing. AA: Conceptualization, supervision, data curation, Writing – review & editing. MG: Supervision, data curation, Writing – review & editing. AI: Data curation, Writing – review & editing. AS: Writing – review & editing. MF: Conceptualization, supervision, data curation, writing -original draft, Investigation, formal analysis.
All authors approved the version to be published and agreed to be accountable for all aspects of the work.
Declaration of competing Interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
Acknowledgements
The authors would like to acknowledge the participating patients for their patience and cooperation. The authors express their gratitude to Princess Nourah bint Abdulrahman University Researchers Supporting Project number (PNURSP2025R811), Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabia in supporting this study, and Cairo University for funding the thesis investigations.
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