Carboxyhemoglobin Research Articles

Evaluation of a Portable Blood Gas Analyzer for Prehospital Triage in Carbon Monoxide Poisoning: Instrument Validation Study.

Carbon monoxide (CO) poisoning is an important cause of morbidity and mortality worldwide. Symptoms are mostly aspecific, making it hard to identify, and its diagnosis is usually made through blood gas analysis. However, the bulkiness of gas analyzers prevents them from being used at the scene of the incident, thereby leading to the unnecessary transport and admission of many patients. While multiple-wavelength pulse oximeters have been developed to discriminate carboxyhemoglobin (COHb) from oxyhemoglobin, their reliability is debatable, particularly in the hostile prehospital environment. The main objective of this pilot study was to assess whether the Avoximeter 4000, a transportable blood gas analyzer, could be considered for prehospital triage. This was a monocentric, prospective, pilot evaluation study. Blood samples were analyzed sequentially with 2 devices: the Avoximeter 4000 (experimental), which performs direct measurements on blood samples of about 50 µL by analyzing light absorption at 5 different wavelengths; and the ABL827 FLEX (control), which measures COHb levels through an optical system composed of a 128-wavelength spectrophotometer. The blood samples belonged to 2 different cohorts: the first (clinical cohort) was obtained in an emergency department and consisted of 68 samples drawn from patients admitted for reasons other than CO poisoning. These samples were used to determine whether the Avoximeter 4000 could properly exclude the diagnosis. The second (forensic) cohort was derived from the regional forensic center, which provided 12 samples from documented CO poisoning. The mean COHb level in the clinical cohort was 1.7% (SD 1.8%; median 1.2%, IQR 0.7%-1.9%) with the ABL827 FLEX versus 3.5% (SD 2.3%; median 3.1%, IQR 2.2%-4.1%) with the Avoximeter 4000. Therefore, the Avoximeter 4000 overestimated COHb levels by a mean difference of 1.8% (95% CI 1.5%-2.1%). The consistency of COHb readings by the Avoximeter 4000 was excellent, with an intraclass correlation coefficient of 0.97 (95% CI 0.93-0.99) when the same blood sample was analyzed repeatedly. Using prespecified cutoffs (5% in nonsmokers and 10% in smokers), 3 patients (4%) had high COHb levels according to the Avoximeter 4000, while their values were within the normal range according to the ABL827 FLEX. Therefore, the specificity of the Avoximeter 4000 in this cohort was 95.6% (95% CI 87%-98.6%), and the overtriage rate would have been 4.4% (95% CI 1.4%-13%). Regarding the forensic samples, 10 of 12 (83%) samples were positive with both devices, while the 2 remaining samples were negative with both devices. The limited difference in COHb level measurements between the Avoximeter 4000 and the control device, which erred on the side of safety, and the relatively low overtriage rate warrant further exploration of this device as a prehospital triage tool.

Carboxyhemoglobin and Methemoglobin Levels and Hemolysis in Children Undergoing Cardiac Surgery With Cardiopulmonary Bypass.

Hemolysis is a complication of cardiopulmonary bypass (CPB). Carboxyhemoglobin (COHb) and methemoglobin (MetHb) were suggested as potential hemolysis biomarkers. This retrospective study was based on a prospective registry aimed to determine the association of COHb and MetHb levels with hemolysis in pediatric patients <4 years old who underwent cardiac surgery with CPB. Plasma-free hemoglobin (PFH), COHb, and MetHb levels were measured before CPB; every 30 minutes during CPB; and on postoperative days 1, 2, and 3. Patients were classified into hemolysis and nonhemolysis groups based on the maximum PFH levels during CPB. A total of 193 patients were included. No significant difference was observed in the maximum COHb levels during CPB (COHb CPB ) between the hemolysis and nonhemolysis groups (1.2% [interquartile range {IQR} 0.9-1.4%] vs. 1.1% [IQR: 0.9-1.4%]; p = 0.17). The maximum MetHb levels during CPB (MetHb CPB ) were significantly higher in the hemolysis group than in the nonhemolysis group (1.3% [IQR: 1.1-1.5%] vs. 1.2% [IQR: 1.0-1.4%]; p = 0.007). Areas under the receiver operating curves of COHb CPB and MetHb CPB were 0.557 (95% confidence interval: 0.475-0.640) and 0.615 (95% confidence interval: 0.535-0.695), respectively. Therefore, the predictive ability of both hemolysis biomarkers during CPB is limited.

Is Carboxyhaemoglobin an Effective Bedside Prognostic Tool for Sepsis and Septic Shock Patients?

Proper management of sepsis poses a challenge even today, with early diagnosis and targeted treatment being the most important steps. Easy, cost-effective bedside tools are needed in order to pinpoint towards the outcome of sepsis or septic shock. This study aims to find a correlation between Sequential Organ Failure Assessment (SOFA), Acute Physiology and Chronic Health Evaluation II (APACHE II) and Simplified Acute Physiology Score II (SAPS II) severity scores, the Neutrophil-Lymphocytes Ratio (NLR) and carboxyhaemoglobin (COHb) levels in septic or septic shock patients with the scope of establishing a bed side cost-effective prognostic tool. A pilot, prospective, observational, and ongoing study was conducted on 61 patients admitted with sepsis or septic shock according to the SEPSIS 3 Consensus definition. We followed clinical and paraclinical parameters on day 1 (D1) and day 5 (D5) after meeting the inclusion criteria. On D1 we found a statistically significant positive correlation between each severity score (p <0.0001), r = 0.7287 for SOFA vs. APACHE II with CI: 0.5841-0.8285, r = 0.6862 for SOFA vs. SAPS II with CI: 0.5251-0.7998 and r = 0.8534 for APACHE II vs. SAPS II with CI: 0.7663 to 0.9097. On D5 we observed similar results: a significant positive correlation between each severity score (p <0.0001), with r = 0.7877 for SOFA vs. APACHE II with CI: 0.6283 to 0.8836, r = 0.8210 for SOFA vs. SAPS II with CI: 0.6822 to 0.9027 and r = 0.8880 for APACHE II vs. SAPS II., CI: 0.7952 to 0.9401. Nil correlation was found between the severity scores, NLR and COHb on D1 and D5. Cost-effective bedside tools to pinpoint towards the outcome of sepsis are yet to be found, however the positive correlation between the severity scores point out to a combination of such tools for prognosis prediction of septic or septic shock patients.

Association of carbon monoxide poisonings and carboxyhemoglobin levels with COVID-19 and clinical severity.

Coronavirus disease 2019 (COVID-19), which recently spread throughout the entire world, is still a significant health issue. Additionally, the most common cause of risky poisoning in emergency services is carbon monoxide (CO) poisoning. Both disorders seem to merit more research as they have an impact on all bodily systems via the lungs. To determine how arterial blood gas and carboxyhemoglobin (COHb) levels affect the clinical and prognostic results of individuals requiring emergency treatment who have both COVID-19 and CO poisoning. Between January 2018 and December 2021, 479 CO-poisoning patients participated in this single-center, retrospective study. Patients were primarily divided into two groups for analysis: Pre-pandemic and pandemic periods. Additionally, the pandemic era was divided into categories based on the presence of COVID-19 and, if present, the clinical severity of the infection. The hospital information system was used to extract patient demographic, clinical, arterial blood gas, COVID-19 polymerase chain reaction, and other laboratory data. The mean age of the 479 patients was 54.93 ± 11.51 years, and 187 (39%) were female. 226 (47%) patients were in the pandemic group and 143 (30%) of them had a history of COVID-19. While the mean potential of hydrogen (pH) in arterial blood gas of all patients was 7.28 ± 0.15, it was 7.35 ± 0.10 in the pre-pandemic group and 7.05 ± 0.16 in the severe group during the pandemic period (P < 0.001). COHb was 23.98 ± 4.19% in the outpatients and 45.26% ± 3.19% in the mortality group (P < 0.001). Partial arterial oxygen pressure (PaO2) was 89.63 ± 7.62 mmHg in the pre-pandemic group, and 79.50 ± 7.18 mmHg in the severe group during the pandemic period (P < 0.001). Despite the fact that mortality occurred in 35 (7%) of all cases, pandemic cases accounted for 30 of these deaths (85.7%) (P <0.001). The association between COHb, troponin, lactate, partial arterial pressure of carbon dioxide, HCO3, calcium, glucose, age, pH, PaO2, potassium, sodium, and base excess levels in the pre-pandemic and pandemic groups was statistically significant in univariate linear analysis. Air exchange barrier disruption caused by COVID-19 may have pulmonary consequences. In patients with a history of pandemic COVID-19, clinical results and survival are considerably unfavorable in cases of CO poisoning.

Effectiveness of the habit of using mask and not using mask on the carboxyhemoglobin (COHb) levels in public transportation workers in Bangkalan district

Introduction: Air pollution is increasing due to industrial and transportation activities in the community. This has an impact on health problems, one of which is respiratory problems. Carbon monoxide (CO) is one of the air pollutants resulting from incomplete combustion of transportation and can be harmful to the human body. The purpose of this study was to analyze the levels of carboxyhemoglobin (CoHb) and the effect of the habit of wearing a mask and not using a mask on COHb levels in public transportation workers in the Bangkalan district. Method: We used analytic observational with cross-sectional design. Respondents used in this study were public transportation workers who had the habit of wearing masks and not wearing masks in the Bangkalan district. COHb levels were checked using the Hinsberg Lang method by reading a UV-Vis spectrophotometer at a wavelength of 414.2 nm with normal values for COHb levels &lt; 3.5%. Results: There were 13% respondents who had the habit of using masks and smoking, 37% respondents were non-smokers and use masks. While respondents who did not have the habit of using masks and smoking were 27% and non-smokers were 23%. Respondents who smoked and used masks had an average COHb level of 8.56%, whereas those who did not smoke and used masks had an average COHb level of 6.50%. Respondents who smoked and did not use masks had an average COHb level of 9.36%, while those who did not smoke and did not use masks had average COHb levels of 8.08%. Bivariate analysis showed that COHb levels were higher in public transportation workers who did not use masks than those who used masks while working (p &lt; 0.05). Conclusion: We discovered a correlation between the habit of wearing a mask and the levels of COHb in those who work in public transport in the Bangkalan District. The analysis of respondents' COHb levels based on the type of mask used and consideration of underlying disease should be done in future studies.

Carbon Monoxide Poisoning: Comparison of Paediatric and Adult Patients

Background: Carbon monoxide (CO) gas is a tasteless, odorless and colorless gas and causes many poisonings every year. In this study, paediatric and adult CO poisoning cases admitted to our emergency department were reviewed retrospectively.&#x0D; Materials and Methods: Paediatric and adult patients who applied to the Emergency Department of Mardin Training and Research Hospital between 01 January 2021 and 31 December 2022 due to CO poisoning due to stove usage were included in the study. Patients were compared according to age, gender, month and time of admission to the emergency department, complaints at admission, laboratory test results and discharge status. &#x0D; Results: 90 patients admitted to the emergency department due to CO poisoning caused by stoves between 2021-2022 were included in the study. While the rate of female patients in the paediatric age group was 53.3%, the rate of female patients in the adult group was 48.9% (p=0.673). When compared according to the complaints of admission to the hospital, the most common complaint in the paediatric age group was nausea-vomiting with 42.2%, while the most common complaint in the adult group was shortness of breath with 26.7%. In both groups, it was determined that the most frequent application was in January with 48.9%. While 15.6% of children were hospitalized, this rate was 4.4% for adults. (p=0.065). While the carboxyhemoglobin (COHb) value at the time of first admission was 18.36±6.60 in the paediatric group, it was 22.03±10.24 in the adult group (p:0.047). In the control blood gas values taken at discharge, COHb level was 2.76±1.83 in children and 5.10±3.02 in adults (p

Carboxyhemoglobin as biomarker of late-onset sepsis in preterm infants

Carboxyhemoglobin (COHb) is considered a biomarker of oxidative stress and previous studies reported an increase in COHb levels in preterm infants who develop late-onset sepsis (LOS). Our aim was to assess the correlation between COHb levels and the risk for LOS development. We retrospectively studied 100 preterm infants, 50 in the LOS and 50 in the no LOS group. COHb levels were measured on the day of diagnosis of the first episode of LOS, 3, 2, and 1 days before and 1 and 4 days after the onset of LOS. Logistic regression analysis showed that a higher level of COHb 2 days before the diagnosis of LOS increases the risk for LOS development (OR 12.150, 95% Cl 1.311–12.605; P = 0.028). A COHb level of 1.55% measured 2 days before the diagnosis of LOS is the best predictive threshold for LOS with a sensitivity of 70% and a specificity of 70%. Conclusion: Increased levels of COHb may predict the diagnosis of LOS in very preterm infants with a good accuracy. If further studies confirm our findings, this easy-to-measure biomarker could provide neonatologists with another tool for monitoring and early diagnosis of sepsis in high-risk patients.What is Known:• Carboxyhemoglobin (COHb) is a biomarker of oxidative stress.• Previous studies reported an increase in COHb levels in preterm infants who develop late-onset sepsis (LOS).What is New:• COHb levels increased two days before the diagnosis of LOS and this increase was associated with the risk for developing LOS.• ROC curve analysis for COHb measured two days before the diagnosis of LOS showed that 1.55% is the best predictive threshold for LOS with a sensitivity of 70% and a specificity of 70%.

Carboxyhemoglobin (COHb): Unavoidable Bystander or Protective Player?

Carbon monoxide (CO) is a cytoprotective endogenous gas that is ubiquitously produced by the stress response enzyme heme-oxygenase. Being a gas, CO rapidly diffuses through tissues and binds to hemoglobin (Hb) increasing carboxyhemoglobin (COHb) levels. COHb can be formed in erythrocytes or in plasma from cell-free Hb. Herein, it is discussed as to whether endogenous COHb is an innocuous and inevitable metabolic waste product or not, and it is hypothesized that COHb has a biological role. In the present review, literature data are presented to support this hypothesis based on two main premises: (i) there is no direct correlation between COHb levels and CO toxicity, and (ii) COHb seems to have a direct cytoprotective and antioxidant role in erythrocytes and in hemorrhagic models in vivo. Moreover, CO is also an antioxidant by generating COHb, which protects against the pro-oxidant damaging effects of cell-free Hb. Up to now, COHb has been considered as a sink for both exogenous and endogenous CO generated during CO intoxication or heme metabolism, respectively. Hallmarking COHb as an important molecule with a biological (and eventually beneficial) role is a turning point in CO biology research, namely in CO intoxication and CO cytoprotection.

Accuracy of pulse CO-oximetry to evaluate blood carboxyhemoglobin level: a systematic review and meta-analysis of diagnostic test accuracy studies.

Carbon monoxide (CO) poisoning is one of the most common causes of poisoning death and its diagnosis requires an elevated carboxyhemoglobin (COHb) level. Noninvasive CO saturation by pulse oximetry (SpCO) has been available since 2005 and has the advantage of being portable and easy to use, but its accuracy in determining blood COHb level is controversial. To evaluate the accuracy of SpCO (index test) to estimate COHb (reference test). Systematic review and meta-analysis of diagnostic test accuracy (DTA) studies. Four electronic databases were searched (Medline, Embase, Cochrane Central Register of Controlled Trials, and OpenGrey) on 2 August 2022. All studies of all designs published since the 2000s evaluating the accuracy and reliability of SpCO measurement compared to blood COHb levels in human volunteers or ill patients, including children, were included. The primary outcome was to assess the diagnostic accuracy of SpCO for estimating COHb by blood sampling by modeling receiver operating characteristic (ROC) curves and calculating sensitivity and specificity (primary measures). The secondary measures were to calculate the limits of agreement (LOA) and the mean bias. This systematic review was conducted according to the Preferred Reporting Items for a Systematic Review and Meta-analysis-DTA 2018 guidelines and has been registered on International Prospective Register of Systematic Reviews (CRD42020177940). The risk of bias was evaluated using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. Twenty-one studies were eligible for the systematic review; 11 could be included for the quantitative analysis of the primary measures and 18 for the secondary measures. No publication bias was found. The area under the summary ROC curve was equal to 86%. The mean sensitivity and specificity were 0.77, 95% confidence interval (CI, 0.66-0.85) and 0.83, 95% CI (0.74-0.89), respectively (2089 subjects and 3381 observations). The mean bias was 0.75% and the LOA was -7.08% to 8.57%, 95% CI (-8.89 to 10.38) (2794 subjects and 4646 observations). Noninvasive measurement of COHb (SpCO) using current pulse CO oximeters do not seem to be highly accurate to estimate blood COHb (moderate sensitivity and specificity, large LOA). They should probably not be used to confirm (rule-in) or exclude (rule-out) CO poisoning with certainty.

Elevated methemoglobin levels in patients treated with high-dose hydroxocobalamin.

The aim of this study was to assess the impact of hydroxocobalamin (OHCbl) infusion on arterial blood gas and oximetry values in patients with vasoplegic syndrome. Blood samples collected from 95 patients receiving OHCbl infusion were assayed using the ABL90 FLEX Plus blood gas analyzer for the concentration of methemoglobin (MetHb), total hemoglobin (tHb), carboxyhemoglobin (COHb), arterial oxygen saturation (SaO2), arterial oxygen partial pressure (PaO2), and arterial carbon dioxide partial pressure (PaCO2). Interference of OHCbl on these variables was evaluated using the measured difference between the preinfusion and postinfusion samples. Blood MetHb (%) measured after the infusion of OHCbl (5g) were significantly higher than the baseline levels, with a median of 4.8 (IQR, 3.0-6.5) versus 1.0 (IQR, 1.0-1.2) (P < .001). Blood COHb (%) increased from a median of 1.3 (IQR, 1.0-1.8) to 1.7 (IQR, 1.3-2.2) (P < .001) following the OHCbl infusion. No differences were seen in median levels of tHb, PaO2, PaCO2, and SaO2 between pre- and post-OHCbl treatment. The presence of OHCbl in blood clearly interfered with the oximetry measurements of the hemoglobin component fractions by falsely increasing the levels of MetHb and COHb. Blood levels of MetHb and COHb cannot be reliably determined by the co-oximetry when OHCbl is known or suspected.

Thoracic cavity fluid as an alternative specimen for carboxyhaemoglobin measurement in post-mortem toxicology

Post-mortem blood is most frequently used for the measurement of carboxyhaemoglobin (COHb) in post-mortem forensic cases, when investigating suspected inhalation of carbon monoxide (CO). However, in many post-mortem cases (especially severe burns and charring deaths), adequate blood specimens are not always available for toxicological analyses. Here, the availability of an alternative specimen for COHb analysis is required. This study investigated the suitability of thoracic cavity fluid (TCF) as an alternative specimen for the measurement of COHb. TCF and comparative blood samples from fifteen potential CO toxicity cases were collected into green-top tubes (containing lithium heparin) and analysed immediately after collection using a validated method on the ABL825 FLEX Radiometer CO-oximeter. Pearson’s correlation coefficient indicated a strong positive relationship between the two specimens (r = 0.975, n = 10, p < 0.001). A statistical agreement between COHb concentrations from blood and TCF was demonstrated using the Bland-Altman plot, with a slight bias of 1.54 % when blood was taken as the standard. This study found that TCF would be a suitable alternative to blood for the measurement of COHb using the ABL825 FLEX blood gas analyser.

Race, hypoxaemia and oxidative stress in prematurely-born infants

BackgroundDisparities in neonatal respiratory outcomes in prematurely-born infants might be partially explained by racial differences and the relationship of hypoxia and oxidative stress. AimsTo determine if Black, preterm infants were exposed more frequently to hypoxaemia compared to White infants and had a higher level of oxidative damage. Study designSingle-centre retrospective cohort study at King's College Hospital, London, UK between 2018 and 2021. SubjectsInfants born before 32 completed weeks of gestational age. Outcome measuresThe median arterial oxygen saturation (SaO2) over the first seven days was measured. The maximum carboxyhaemoglobin (COHb) level for the first three days was also recorded as an index of oxidative stress. ResultsTwo thousand and sixty blood gases from 87 infants (38 Black) with a median (IQR) gestational age of 26.4 (24.6–28.3) weeks were analysed. The median (IQR) SaO2 was not significantly different in Black [96.1 (95.2–96.8) %] compared to White infants [96.7 (95.6–97.7) %, p = 0.24]. The median (IQR) COHb was not significantly different in Black infants [1.9 (1.7–2.4) %] compared to White infants [1.9 (1.7–2.3) %, p = 0.77]. The highest COHb was significantly related to the median SaO2 in all infants (r = −0.51, p < 0.001) and separately in Black (r = −0.50, p = 0.002) and White (r = −0.56, p < 0.001) infants. ConclusionsPreterm, Black infants were not exposed more frequently to hypoxaemia compared to White infants. Lower saturation levels were associated with higher maximum carboxyhaemoglobin levels indicating a higher risk of oxidative stress, irrespective of racial background.

Comparison of Carboxyhemoglobin (COHb) Levels in the Blood of Active and Passive Smokers in Bulupitu Bus Terminal Workers, Banyumas Regency

Carbon monoxide (CO) is a colorless, tasteless, and odorless gas, but in high concentrations in the blood, it can cause death. One of the CO2 can come from cigarette smoke. When cigarette smoke is inhaled, the affinity of CO with the blood is stronger than for oxygen, and this will increase the carboxyhemoglobin (HbCO) in the blood. Passive smokers who are often near active smokers will inhale cigarette smoke. This study aims to compare HbCO levels in the blood between active and passive smokers of Bulupitu terminal workers, Banyumas Regency. This was an analytical observational study with six active and six passive smokers who are terminal workers. All active and passive smokers samples had HbCO concentrations above the normal HbCO threshold of 3.5%. The measurement results showed the average HbCO level of smokers was 5.87%. Determining differences in HbCO levels in the blood of active and passive smokers was conducted using the Independent Test (p-value = 0.370). This value shows no significant difference in blood HbCO levels in active and passive smokers.

Clinical and Laboratory Characteristics Predicting the Severity of Carbon Monoxide Poisoning in Children: A Single-Center Retrospective Study.

Carbon monoxide poisoning (COP) is extremely common throughout the world. The purpose of this study was to assess the demographic, clinical, and laboratory characteristics predicting the severity COP in children. The study included 380 children diagnosed with COP between January 2017 and January 2021 and 380 healthy controls. Carbon monoxide poisoning was diagnosed based on the medical history and a carboxyhemoglobin (COHb) level of more than 5%. The patients were classified as mild (COHb 10%), moderate (COHb 10%-25%), or severely (COHb > 25%) poisoned. The mean age of the severe group was 8.60 ± 6.30, for the moderate group was 9.50 ± 5.81, for the mild group was 8.79 ± 5.94, and for the control group was 8.95 ± 5.98. The most common place of exposure was at home and all cases were affected accidentally. The coal stove was the most common source of exposure, followed by natural gas. The most common symptoms were nausea/vomiting, vertigo, and headache. Neurologic symptoms such as syncope, confusion, dyspnea, and seizures were more common in the severe group. A total of 91.3% of the children had hyperbaric oxygen therapy, 3.8% were intubated, and 3.8% were transferred to intensive care in the severe group, whereas no death or sequela was observed. Mean platelet volume and red cell distribution width had the highest area under the curve in the receiver operating characteristic analysis (0.659; 0.379). A positive and low statistically significant relationship was found between COHb levels and troponin and lactate levels in the severe group ( P < 0.05). Carbon monoxide poisoning progressed more severely in children presented with neurological symptoms and have elevated red cell distribution width and mean platelet volume. Even in severe COP cases, satisfactory results have been obtained with early and appropriate treatment.

Potential effects of carbon monoxide donor and its nanoparticles on experimentally induced gastric ulcer in rats

The prevalence of gastric ulcers is increasing worldwide, especially those brought on by non-steroidal anti-inflammatory drugs (NSAIDS), so prevention is extremely crucial. The protective potential of carbon monoxide (CO) in several inflammatory disorders has been clarified. The goal of the current study was to investigate the gastroprotective effect of CO produced by its pharmacological donor (CORM2) and its nanoparticles (NPs) against indomethacin (INDO)-induced ulcers. Investigations on CORM2's dose-dependent effects were also conducted. For induction of gastric ulcer, 100 mg kg−1 of INDO was given orally. Before ulcer induction, CORM2 (5, 10, and 15 mg kg−1), CORM2 nanoparticles (5 mg kg−1), or ranitidine (30 mg kg−1) were given intraperitoneally for 7 days. Ulcer score, gastric acidity, gastric contents of malondialdehyde (MDA), nitric oxide (NO), heme oxygenase-1 (HO-1), and carboxyhemoglobin (COHb) blood content were estimated. Additionally, gene expression of nuclear factor erythroid 2-related factor 2 (NRF2) and immunohistochemical staining of cyclooxygenase-1 (COX-1) as well as cyclooxygenase-2 (COX-2) were analyzed. Results demonstrated a substantial dose-dependent decrease in ulcer score, pro-inflammatory indicators, and oxidative stress markers with CORM2 and its NPs. Furthermore, CORM2 and its NPs markedly increased NRF2, COX-1, and HO-1, but CORM2 NPs outperformed CORM2 in this regard. In conclusion, the CO released by CORM2 can protect against INDO-induced gastric ulcers dose dependently, and the highest used dose had no effect on COHb concentration.

Analyses of physical factors that contribute to the blood carboxyhemoglobin saturation in autopsy cases of house fire fatalities

The authors analyzed data from forensic autopsies of 75 patients who died as a result of house fires to clarify the physical factors that affect blood carboxyhemoglobin (COHb) saturation. Blood COHb saturation levels were significantly lower in patients who survived in the hospital. No significant differences were found in the blood COHb saturation levels between patients who died immediately at the scene and those who were pronounced dead at the receiving hospital without heartbeat being restored. The COHb saturation levels were significantly different among the groups of patients classified by the amount of soot. Although age, coronary artery stenosis, and blood alcohol concentration did not significantly affect blood COHb saturation, on comparing patients who died in the same fire, lower COHb saturation was observed in two patients, one with severe coronary artery stenosis and other with severe alcohol intoxication. To accurately interpret blood COHb saturation during forensic autopsy, the heartbeat status (present or absent) at the time of the rescue and the amount of soot in the trachea must be determined. Low levels of COHb saturation may be observed in fatalities with severe coronary atherosclerosis or severe alcohol intoxication.

AN OVERVIEW OF CARBON MONOXIDE DEATHS IN KUWAIT BETWEEN YEARS 2013-2019 WITH FOUR RARE CASES PRESENTATION: A FORENSIC PRACTITIONER EXPERIENCE.

Background: Carbon monoxide (CO) is an odorless, colorless, non-irritating highly toxic gas produced after the incomplete combustion of hydrocarbons. CO forms carboxyhaemoglobin (COHb), which will lead to severe tissue hypoxia and death in some cases. Materials and Method: In the present study, we will discuss the commonest causes of deaths due to CO toxicity in Kuwait between the years 2013-2019 from the perspective of a forensic medicine practitioner in the Forensic Medicine Department in the General Administration for Criminal Evidence – Ministry of Interior- Kuwait. Additionally, we present a rare accidental death of four cases (2 male and female partners), which were handled in 2015 and 2016 in the Forensic Medicine Department. Each couple was found dead in a car parked in an open space and the lethal levels of COHb were detected in their bloods. Result and conclusion: Between the years 2013-2019, in every 100 cases of non-criminal deaths that occur yearly in Kuwait, there were 1-3 cases of CO accidental poisoning (1-2%). The ages ranged from 9 months until 81 years. The range of the COHb concentration in the blood sample was from 36.5% to 80%. The most common cause was smoke inhalation in fires (60%). Defective coal stove was less common which is believed to occur only during winter months (20%). Consequently, the presentation of four autopsies of cases found dead in closed cars in open spaces, after accidental lethal CO inhalation, was worth mentioning. After expert examination, both cars showed defective engines where the CO level increases inside the cabinet which led to death while the cars were in an open land. These cases are worthwhile reporting being rarely described in forensic toxicology.

Carboxyhemoglobin Levels in Preterm Neonatal Late-Onset Sepsis: to Predict or not to Predict.

In this study, we aimed to evaluate carboxyhemoglobin (COHb) levels in diagnosing late-onset sepsis (LOS) in preterm neonates. The records of culture-positive LOS in preterm neonates hospitalized in NICU from January 2017 to July 2022 were reviewed. COHb levels, C-reactive protein, procalcitonin, and neutrophil to lymphocyte ratio of septic preterm infants were compared to controls. In addition, serial COHb levels measured within six hours before or 24h after blood culture sampling, three to seven days prior, and three to five days after starting antimicrobial therapy were retrieved from patient records. The study included 77 blood-culture-positive preterm infants and 77 non-septic controls. During the LOS episode, the COHb values were found to be significantly increased (median: 1.8, IQR: 1.4-2.5) when compared to the control group (median: 1.2, IQR: 0.8-1.6) (p < 0.001). ROC analysis yielded an AUC of 0.714 for COHb (95% CI: 0.631-0.796, p<0.001). At an optimal cut-off of >1.5%, the test's sensitivity was 64.94%, the specificity was 72.73%, the positive predictive value was 70.42%, and the negative predictive value was 67.47%. LOS led to a dramatic rise followed by a decrease after the initiation of the antimicrobial therapy [1.8 (1.4-2.5)] vs. [1.45 (0.2-4)] p<0.001. COHb levels increased at the beginning of LOS, decreasing in response to antibiotics. When used in conjunction with other sepsis biomarkers, the variation of COHb can be important in evaluating late-onset sepsis episodes in preterm infants.

Predictive markers related to local and systemic inflammation in severe COVID-19-associated ARDS: a prospective single-center analysis

BackgroundAs the COVID-19 pandemic strains healthcare systems worldwide, finding predictive markers of severe courses remains urgent. Most research so far was limited to selective questions hindering general assumptions for short- and long-term outcome.MethodsIn this prospective single-center biomarker study, 47 blood- and 21 bronchoalveolar lavage (BAL) samples were collected from 47 COVID-19 intensive care unit (ICU) patients upon admission. Expression of inflammatory markers toll-like receptor 3 (TLR3), heme oxygenase-1 (HO-1), interleukin (IL)-6, IL-8, leukocyte counts, procalcitonin (PCT) and carboxyhemoglobin (CO-Hb) was compared to clinical course. Clinical assessment comprised acute local organ damage, acute systemic damage, mortality and outcome after 6 months.ResultsPCT correlated with acute systemic damage and was the best predictor for quality of life (QoL) after 6 months (r = − 0.4647, p = 0.0338). Systemic TLR3 negatively correlated with impaired lung function (ECMO/ECLS: r = − 0.3810, p = 0.0107) and neurological short- (RASS mean: r = 0.4474, p = 0.0023) and long-term outcome (mRS after 6 m: r = − 0.3184, p = 0.0352). Systemic IL-8 correlated with impaired lung function (ECMO/ECLS: r = 0.3784, p = 0.0161) and neurological involvement (RASS mean: r = − 0.5132, p = 0.0007). IL-6 in BAL correlated better to the clinical course than systemic IL-6. Using three multivariate regression models, we describe prediction models for local and systemic damage as well as QoL. CO-Hb mean and max were associated with higher mortality.ConclusionsOur predictive models using the combination of Charlson Comorbidity Index, sex, procalcitonin, systemic TLR3 expression and IL-6 and IL-8 in BAL were able to describe a broad range of clinically relevant outcomes in patients with severe COVID-19-associated ARDS. Using these models might proof useful in risk stratification and predicting disease course in the future.Trial registration The trial was registered with the German Clinical Trials Register (Trial-ID DRKS00021522, registered 22/04/2020).

ВЛИЯНИЕ КУРЕНИЯ НА ПОКАЗАТЕЛИ ОКИСИ УГЛЕРОДА И ОКСИДА АЗОТА В ВЫДЫХАЕМОМ ВОЗДУХЕ У ПАЦИЕНТОВ С ХРОНИЧЕСКОЙ ОБСТРУКТИВНОЙ БОЛЕЗНЬЮ ЛЕГКИХ

To date, points of view regarding the effect of smoking on the indicators of exhaled air are very contradictory, especially with regard to the examination of patients with chronic obstructive pulmonary disease (COPD) suffering from tobacco dependence. Basically, a comparative analysis is carried out by researchers solely on the fact of the presence of tobacco dependence, without taking into account the indicator of the smoking index (CI), as such, or the data obtained from the examination of smoking COPD patients and healthy volunteers are compared. Objective: to evaluate the change in the concentration of carbon monoxide (CO), nitric monoxide (NO) and carboxyhemoglobin (COHb) in the exhaled air of patients with COPD, depending on the status of smoking and CI. Material and research methods. 96 patients with COPD were examined, the average age of which was 54.6±5.9 years, the duration of the disease was 15±4.8 years. 70 patients (72.9%) who participated in the study suffered from tobacco dependence, while CI ≤10 pack-year was observed in 2.8% of them, 11-20 pack-year in 42.9%, 21-30 pack-year in 40.0% and &gt;30 pack-year in 14.3%. As part of a comprehensive examination, all patients underwent determination of CO (ppm) and COHb (%) in exhaled air using the MicroCO device (Micro medica, UK) and the level of NO was assessed using the Niox Mino analyzer (Aerocline, Sweden). The results of the study. During the analysis of the obtained data, we noted an increase in the average concentration of CO in the exhaled air in all smoking patients, while the increase in the indicator was directly proportional to the CI. A similar picture was observed with respect to the COHb level. The concentration of NO in the exhaled air, on the contrary, showed a tendency to decrease with increasing CI. A comparative analysis of the obtained data was carried out in three groups: I - non-smoking patients with COPD (n=26), II - patients with COPD with an IC of 11-20 pack-years (n=30) and III – patients with COPD with an IC of 21-30 pack-years (n=28). In terms of peripheral blood saturation, significant differences compared with the group of non-smokers were found in patients with IC 11-20 pack-years and with IC 21-30 pack-years, while there were no statistically significant differences between these groups of smoking patients. The CO level in smokers, regardless of CI, was significantly higher than in non-smokers, while in COPD patients with CI 21-30 pack-year it was also significantly higher than in patients with CI 11-20 pack-year. The COHb index in smokers with COPD was also significantly higher than in non-smokers, but when comparing data in the group with IC 11-20 pack-years and IC 21-30 pack/years, no statistically significant differences were found. In terms of NO in exhaled air, statistically significant differences were noted when comparing data in the group of non-smoking patients with COPD with the results obtained in groups of patients with IC 11-20 pack-years and with IC 21-30 pack-years, as well as when comparing data in these groups of smokers among themselves. Conclusions. The study revealed a statistically significant increase in the level of CO in the exhaled air, depending on the status of smoking and CI. It was determined that the smoking factor in COPD patients affects the level of NO in the exhaled air, causing its significant decrease in COPD patients with CI &gt;10 pack-year compared to non-smoking COPD patients.