Hyperbaric Oxygen and Mortality in Burns With Inhalation Injury: A Study of the National Burn Repository.

Mortality in burn injury is primarily influenced by three factors: age, percent burn (%TBSA), and presence of inhalation injury. Numerous modalities have been tried in an attempt to treat those patients with burns and inhalation injury, including the use of hyperbaric oxygen (HBO). The aim of our study was to find the national prevalence of HBO for burns with inhalation injury, and whether HBO influenced mortality in these often severely injured patients. This retrospective study used the National Burn Repository (NBR) to identify hospital admissions of patients with both cutaneous burn and inhalation injuries. After applying exclusion criteria, a total of 13,044 patients were identified. Variables included in the multivariate regression analysis included age, sex, race, payer, mechanism of burn injury, TBSA group, total procedure number, mechanical ventilator days, and treatment with HBO. The main outcome variable was mortality. Of the 13,044 patients, 67 had HBO therapy. The HBO patients were older (mean age 51.7 vs 42.8 years, P < .001), but had smaller burns and thus a similar Baux score (66.6 vs 65.2, P = .661). The HBO patients had a higher mortality (29.9% vs 17.5%, P = .01). On multivariate regression analysis, HBO was an independent predictor of mortality (odds ratio = 2.484, P = .004). Other significant predictors of mortality included age, black race, Medicaid or uninsured patients, and %TBSA. The use of HBO for patients with burns and inhalation injury is uncommon in this database. It is unclear whether that reflects low prevalence or if individual centers do not all impute HBO into the NBR. For those patients in this database, HBO is an independent predictor of mortality. It can be difficult to determine the severity of inhalation injury in the NBR, so those patients receiving HBO could theoretically have more severe inhalation injury.

Carbon monoxide poisoning in Denmark with focus on mortality and factors contributing to mortality.

INTRODUCTION: Carbon monoxide (CO) poisoning is frequent worldwide but knowledge regarding the epidemiology is insufficient. The aim of this study was to clarify the extent of this intoxication, its mortality and factors associated with mortality. MATERIALS AND METHODS: National databases from Statistics Denmark were used to identify individuals who suffered from CO-poisoning during 1995-2015, as well as information regarding co-morbidities, mortality and manner of death. RESULTS: During the period from 1995 to 2015, 22,930 patients suffered from CO-poisoning in Denmark, and 21,138 of these patients (92%) were hospitalized. A total of 2,102 patients died within the first 30 days after poisoning (9.2%). Among these, 1,792 (85% of 2,102) were declared dead at the scene and 310 (15% of 2,102) died during hospitalization. Deaths due to CO-poisoning from smoke were intentional in 6.3% of cases, whereas deaths due to CO containing gases were intentional in 98.0% of cases. Among patients who survived >30 days, there was no significant difference in survival when comparing hyperbaric oxygen therapy (HBO) treatment with no HBO treatment after adjustment for age and co-morbidities such as drug abuse, psychiatric disease, stroke, alcohol abuse, arterial embolism, chronic obstructive pulmonary disease, cerebrovascular disease and atrial fibrillation. Several co-morbidities predicted poorer outcomes for patients who survived the initial 30 days. CONCLUSIONS: Poisoning from smoke and/or CO is a frequent incident in Denmark accounting for numerous contacts with hospitals and deaths. Both intoxication and mortality are highly associated with co-morbidities interfering with cognitive and physical function. Treatment with HBO was not seen to have an effect on survival.

Characteristics and outcome of children with carbon monoxide poisoning with and without smoke exposure referred for hyperbaric oxygen therapy.

OBJECTIVES: To describe the clinical characteristics and outcome of children with carbon monoxide (CO) poisoning with and without smoke exposure referred for hyperbaric oxygen therapy (HBOT), and to determine the association between any of these characteristics and death. SETTING: Regional hyperbaric referral center. PATIENTS: The medical records of 150 children with CO poisoning (COP) who were treated with HBOT between August 92 and September 95 were reviewed. MEASUREMENTS/MAIN RESULTS: COP was defined as a history of probable exposure to CO, with either a carboxyhemoglobin level (COHb) > 25, or COHb < 25 with neurological, respiratory, or cardiac compromise. Major cutaneous burns were described as second degree burns over greater than 20% of the patient's total body surface area (TBSA), or third degree burns over greater than 10% of the patient's TBSA. Children extracted from a closed-space fire who had airway soot, singed facial hair/facial burns, or respiratory distress were defined as having smoke inhalation and carbon monoxide poisoning (CO/SI). CO/SI occurred in 40.1% of patients. Compared to children with COP alone, those with CO/SI were significantly more likely to have a depressed mental status upon arrival to an ED (76.3 % vs 13.6 %, P < 0.001), lower mean initial GCS (6.7 vs 14.7, P < 0.001), lower mean initial pH (7.2 vs 7.4, P < 0.001), respiratory arrest at the scene (68.5% vs 0%, P < 0.001), and cardiac arrest at the scene (25.9% vs 0%, P < 0.001). Children with CO/SI were significantly more likely to have a poor outcome (death) than children with COP alone (22.6% vs. 0%, P < 0.001). Comparing children with CO/SI who died versus survivors, there were significant differences in mean initial COHb (38.3 vs 24.3, P = 0.03), mean initial temperature upon arrival in an ED (94.9 degrees F vs 98.2 degrees, P < 0.006), respiratory arrest at the scene (92% vs 59.6%, P = 0.04), and cardiac arrest at the scene (66.7% vs 13.5%, P < 0.001). Sixty percent of children died who had a combination of risk factors of smoke inhalation, low temperature, high COHb level, and respiratory and cardiac arrest in the field. CONCLUSIONS: These preliminary data suggest that children with COP alone who are treated with HBOT are at low risk for dying regardless of initial COHb level. Children with CO/SI have a significantly higher risk of dying than those children with COP alone. A combination of smoke inhalation, low temperature, high COHb level, respiratory arrest, and cardiac arrest is highly associated with death. Prospective studies are needed to confirm and further define these associations.

Toxicological aspects of firesmoke: polymer pyrolysis and combustion.

Combustion toxicology is a complex field, and predicting the thermal breakdown products of natural and synthetic polymers is an inexact science. Practitioners of emergency medicine, occupational and environmental medicine, industrial hygiene, and toxicology must keep in mind a wide range of potential combustion and pyrolysis products when dealing with clinical and regulatory issues in fire safety.