Validation of a Spectrophotometric Method for Quantification of Carboxyhemoglobin

Universidade de São Paulo - LIM[40/HC-FM-USP]

A New Approach for the Carbon Monoxide (CO) Exposure Diagnosis: Measurement of Total CO in Human Blood Versus Carboxyhemoglobin (HbCO).

The aim of the study is to present the application of a headspace-gas chromatography-mass spectrometry (HS-GC-MS) method for the determination of the carbon monoxide (CO) blood concentration and to compare it with carboxyhemoglobin (HbCO) saturation. In postmortem cases, the HbCO measured by spectrophotometry frequently leads to inaccurate results due to inadequate samples or analyses. The true role of CO intoxication in the death of a person could be misclassified. The estimation of HbCO from HS-GC-MS CO measurements provides helpful information by determining the total CO levels (CO linked to hemoglobin (HbCO) and CO dissociated from hemoglobin). The CO concentrations were converted in HbCO saturation levels to define cutoff blood CO values. CO limits were defined as less than 1 μmol/mL for living persons, less than 1.5 μmol/mL for dead persons without CO exposure, and greater than 3 μmol/mL for dead persons with clear CO poisoning.

Non invasive transcutaneous blood carboxyhemoglobine level: reliability in victims of carbon monoxide poisoning

Introduction: Carbon monoxide (CO) poisoning is one of the mostcommon causes of fatal poisoning. Symptoms of CO poisoning arenonspecific and the documentation of elevated carboxyhemoglobin(HbCO) levels in arterial blood sample is the only standard ofconfirming suspected exposure. The treatment of CO poisoning requiresnormobaric or hyperbaric oxygen therapy, according to the symptomsand HbCO levels. A new device, the Rad-57 pulse CO-oximeter allowsnoninvasive transcutaneous measurement of blood carboxyhemoglobinlevel (SpCO) by measurement of light wavelength absorptions.Methods: Prospective cohort study with a sample of patients, admittedbetween October 2008 - March 2009 and October 2009 - March 2010,in the emergency services (ES) of a Swiss regional hospital and aSwiss university hospital (Burn Center). In case of suspected COpoisoning, three successive noninvasive measurements wereperformed, simultaneously with one arterial blood HbCO test. A controlgroup includes patients admitted in the ES for other complaints (cardiacinsufficiency, respiratory distress, acute renal failure), but necessitatingarterial blood testing. Informed consent was obtained from all patients.The primary endpoint was to assess the agreement of themeasurements made by the Rad-57 (SpCO) and the blood levels(HbCO).Results: 50 patients were enrolled, among whom 32 were admittedfor suspected CO poisoning. Baseline demographic and clinicalcharacteristics of patients are presented in table 1. The median age was37.7 ans ± 11.8, 56% being male. Median laboratory carboxyhemoglobinlevels (HbCO) were 4.25% (95% IC 0.6-28.5) for intoxicated patientsand 1.8% (95% IC 1.0-5.3) for control patients. Only five patientspresented with HbCO levels >= 15%. The results disclose relatively faircorrelations between the SpCO levels obtained by the Rad-57 and thestandard HbCO, without any false negative results. However, theRad-57 tend to under-estimate the value of SpCO for patientsintoxicated HbCO levels >10% (fig. 1).Conclusion: Noninvasive transcutaneous measurement of bloodcarboxyhemoglobin level is easy to use. The correlation seems to becorrect for low to moderate levels (<15%). For higher values, weobserve a trend of the Rad-57 to under-estimate the HbCO levels. Apartfrom this potential limitation and a few cases of false-negative resultsdescribed in the literature, the Rad-57 may be useful for initial triageand diagnosis of CO.

Three short perioperative infusions of n-3 PUFAs reduce systemic inflammation induced by cardiopulmonary bypass surgery: a randomized controlled trial.

BACKGROUND: Fish oil (FO) has antiinflammatory effects, which might reduce systemic inflammation induced by a cardiopulmonary bypass (CPB). OBJECTIVE: We tested whether perioperative infusions of FO modify the cell membrane composition, inflammatory responses, and clinical course of patients undergoing elective coronary artery bypass surgery. DESIGN: A prospective randomized controlled trial was conducted in cardiac surgery patients who received 3 infusions of 0.2 g/kg FO emulsion or saline (control) 12 and 2 h before and immediately after surgery. Blood samples (7 time points) and an atrial biopsy (during surgery) were obtained to assess the membrane incorporation of PUFAs. Hemodynamic data, catecholamine requirements, and core temperatures were recorded at 10-min intervals; blood triglycerides, nonesterified fatty acids, glucose, lactate, inflammatory cytokines, and carboxyhemoglobin concentrations were measured at selected time points. RESULTS: Twenty-eight patients, with a mean ± SD age of 65.5 ± 9.9 y, were enrolled with no baseline differences between groups. Significant increases in platelet EPA (+0.86%; P = 0.0001) and DHA (+0.87%; P = 0.019) were observed after FO consumption compared with at baseline. Atrial tissue EPA concentrations were higher after FO than after control treatments (+0.5%; P < 0.0001). FO did not significantly alter core temperature but decreased the postoperative rise in IL-6 (P = 0.018). Plasma triglycerides increased transiently after each FO infusion. Plasma concentrations of glucose, lactate, and blood carboxyhemoglobin were lower in the FO than in the control group on the day after surgery. Arrhythmia incidence was low with no significant difference between groups. No adverse effect of FO was detected. CONCLUSIONS: Perioperative FO infusions significantly increased PUFA concentrations in platelet and atrial tissue membranes within 12 h of the first FO administration and decreased biological and clinical signs of inflammation. These results suggest that perioperative FO may be beneficial in elective cardiac surgery with CPB. This trial was registered at clinicaltrials.gov as NCT00516178.

Ignition of a human body by a modest external source: a case report.

A case of sustained combustion of a human body that occurred in 2006 in Geneva, Switzerland, is presented. The body of a man was discovered at home and found to have been almost completely incinerated between the knees and the mid-chest, with less damage to the head, arms, lower legs and feet. His dog was also found dead just behind the house door. The external source of ignition was most likely a cigarette or a cigar. The chair in which the man had been sitting was largely consumed while other objects in the room exhibited only a brown oily or greasy coating and were virtually undamaged. Toxicological analyses carried out on the blood from the lower legs showed low levels of desalkylflurazepam. Alcohol concentration was 1.10 per thousand, carboxyhaemoglobin levels were 12% and cyanide concentration was 0.05 mg/L. Toxicological analyses carried out on the dog's blood showed carboxyhaemoglobin levels at 65%.

Tobacco experimental model to induce urinary bladder neoplasms

OBJECTIVE: to develop an experimental model of exposure to tobacco burning (cigarette) products to assess the effects of its chronic use in relation to cancers of the bladder. METHODS: the animals were chronically exposed to the burning tobacco products in a semi-open chamber to simulate smoking. Thirty young Wistar rats were divided into two groups: one with 20 animals simulating smoking for six months, and ten not exposed control animals for the same period. After exposure by inhalation of cigarette smoke, animals were euthanized and subjected to histopathological study of the bladder wall. RESULTS: no tumor was found but mild and non significant alterations. The studies of hemo-oximetry (carboxyhemoglobin and methemoglobin) and the concentration of carbon dioxide (CO2) confirm that the animals were exposed to high concentrations of tobacco smoke and its derivatives. CONCLUSION: no bladder mucosal neoplasia was found in the pathological study of animals. The developed experimental models were highly efficient, practical and easy to use and can be used in other similar studies to determine the harmful effects caused by smoking.

The caprine oxyhemoglobin dissociation curve

The caprine oxyhemoglobin dissociation curve has not been previously defined. Blood from 10 healthy goats was equilibrated in a tonometer with calibrated gas mixtures of oxygen at concentrations of 95%, 21%, 13%, 12%, 10%, 9%, 8%, 5%, 4% and 2.5%, 5% carbon dioxide, balance nitrogen. The pH, partial pressure of oxygen (PO2), partial pressure of carbon dioxide (PCO2), total hemoglobin, oxyhemoglobin saturation, carboxyhemoglobin, methemoglobin, and oxygen content were measured. The PO2/oxyhemoglobin and the PO2/oxygen content relationships were graphed with curve-fitting software and a formula for calculating oxyhemoglobin from PO2 was generated. The maximum oxygen content per gram of hemoglobin was 1.29 ml of oxygen per gram of hemoglobin. The PO2 at which hemoglobin was 50% saturated (P-50) from the PO2/oxyhemoglobin relationship was 28.6 +/- 1.5 mmHg and that from the PO2/oxygen content relationships was 29.1 +/- 1.6 mmHg. The Hill coefficient for the PO2/oxyhemoglobin data was 3.0 +/- 0.4. (c) 2005 Elsevier Ltd. All rights reserved.

Smoking is associated with remodeling of gap junction in the rat heart: Smoker's paradox explanation?

Background: In a previous study utilizing the rat model, exposure to tobacco smoke for 5 weeks increased survival after AMI, despite similar age and infarct size between the smokers and nonsmokers, and absence of reperfusion. Objective: Thus, this study aimed to analyze the effects of exposure to tobacco smoke on intensity, distribution or phosphorylation of connexin 43 in the rat heart. Methods: Wistar rats weighing 100 g were randomly allocated into 2 groups: 1) Control (n = 25); 2) Exposed to tobacco smoke (ETS), n = 23. After 5 weeks, left ventricular morphometric analysis, immunohisthochemistry and western blotting for connexin 43 (Cx43) were performed. Results: Collagen volume fraction, cross-sectional areas, and ventricular weight were not statistically different between control and ETS. ETS showed lower stain intensity of Cx43 at intercalated disks (Control: 2.32 ± 0.19; ETS: 1.73 ± 0.18; p = 0.04). The distribution of CX43 at intercalated disks did not differ between the groups (Control: 3.73 ± 0.12; ETS: 3.20 ± 0.17; p = 0.18). ETS rats showed higher levels of dephosphorylated form of Cx43 (Control: 0.45 ± 0.11; ETS: 0.90 ± 0.11; p = 0.03). On the other hand, total Cx43 did not differ between control and ETS groups (Control: 0.75 ± 0.19; ETS: 0.93 ± 0.27; p = 0.58). Conclusion: Exposure to tobacco smoke resulted in cardiac gap junction remodeling, characterized by alterations in the quantity and phosphorylation of the Cx43, in rats hearts. This finding could explain the smoker's paradox observed in some studies.

Transporte mucociliar em fumantes participantes de um programa de cessação do tabagismo

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Nasal and systemic inflammatory profile after short term smoking cessation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

GSR deposition along the bullet path in contact shots to composite models

In contact shots, all the materials emerging from the muzzle (combustion gases, soot, powder grains, and metals from the primer) will be driven into the depth of the entrance wound and the following sections of the bullet track. The so-called "pocket" ("powder cavity") under the skin containing soot and gunpowder particles is regarded as a significant indicator of a contact entrance wound since one would expect that the quantity of GSR deposited along the bullet's path rapidly declines towards the exit hole. Nevertheless, experience has shown that soot, powder particles, and carboxyhemoglobin may be found not only in the initial part of the wound channel, but also far away from the entrance and even at the exit. In order to investigate the propagation of GSRs under standardized conditions, contact test shots were fired against composite models of pig skin and 25-cm-long gelatin blocks using 9-mm Luger pistol cartridges with two different primers (Sinoxid® and Sintox®). Subsequently, 1-cm-thick layers of the gelatin blocks were examined as to their primer element contents (lead, barium, and antimony as discharge residues of Sinoxid® as well as zinc and titanium from Sintox®) by means of X-ray fluorescence spectroscopy. As expected, the highest element concentrations were found in the initial parts of the bullet tracks, but also the distal sections contained detectable amounts of the respective primer elements. The same was true for amorphous soot and unburned/partly burned powder particles, which could be demonstrated even at the exit site. With the help of a high-speed motion camera it was shown that for a short time the temporary cavitation extends from the entrance to the exit thus facilitating the unlimited spread of discharge residues along the whole bullet path.

Effect of smoke inhalation on viscoelastic properties and ventilation distribution in sheep

Smoke inhalation injuries are the leading cause of mortality from burn injury. Airway obstruction due to mucus plugging and bronchoconstriction can cause severe ventilation inhomogeneity and worsen hypoxia. Studies describing changes of viscoelastic characteristics of the lung after smoke inhalation are missing. We present results of a new smoke inhalation device in sheep and describe pathophysiological changes after smoke exposure. Fifteen female Merino ewes were anesthetized and intubated. Baseline data using electrical impedance tomography and multiple-breath inert-gas washout were obtained by measuring ventilation distribution, functional residual capacity, lung clearance index, dynamic compliance, and stress index. Ten sheep were exposed to standardized cotton smoke insufflations and five sheep to sham smoke insufflations. Measured carboxyhemoglobin before inhalation was 3.87 +/- 0.28% and 5 min after smoke was 61.5 +/- 2.1%, range 50-69.4% ( P < 0.001). Two hours after smoke functional residual capacity decreased from 1,773 +/- 226 to 1,006 +/- 129 ml and lung clearance index increased from 10.4 +/- 0.4 to 14.2 +/- 0.9. Dynamic compliance decreased from 56.6 +/- 5.5 to 32.8 +/- 3.2 ml/ cmH(2)O. Stress index increased from 0.994 +/- 0.009 to 1.081 +/- 0.011 ( P < 0.01) ( all means +/- SE, P < 0.05). Electrical impedance tomography showed a shift of ventilation from the dependent to the independent lung after smoke exposure. No significant change was seen in the sham group. Smoke inhalation caused immediate onset in pulmonary dysfunction and significant ventilation inhomogeneity. The smoke inhalation device as presented may be useful for interventional studies.

Exposición a monóxido de carbono en trabajadores de control vehicular-Cuenca: estudio exploratorio

El presente estudio exploratorio evalúa la exposición al monóxido de carbono (CO), expresado en porcentaje de carboxihemoglobina (%COHb), entre los trabajadores de los centros de control vehicular (CRV) DANTON-Cuenca. Todos los trabajadores (n=55) de los CRVs de Capulispamba y Mayancela participaron en este estudio. El %COHb se determinó a partir de muestras de sangre tomadas al inicio y final de un día laboral de febrero, abril y julio de 2013. Los resultados muestran que el %COHb se incrementó del inicio al final de la jornada laboral en ambos CRVs tanto en el grupo de trabajadores que fuman y no fumadores (P<0.001). Entre los no fumadores (N=42), el %COHb al final de la jornada sobrepasó el valor límite biológico (VLB) para COHb (3.5%) únicamente en el CRV de Mayancela (4.12%, P<0.05). Entre los fumadores (N=13), los promedios de %COHb al final de la jornada sobrepasaron los VLB en ambos CRVs. Se concluye, que los trabajadores de los CRVs de Mayancela y aquellos que fuman presentan %COHb mayores al VLB.