Near infrared optical monitoring of cat skeletal muscle during hypercapnia.
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Animals↗
Biomedical subjects
N B Hampson
Publications and source records attributed to N B Hampson.
Selection criteria utilized for hyperbaric oxygen treatment of carbon monoxide poisoning.
Medical directors of North American hyperbaric oxygen (HBO) facilities were surveyed to assess selection criteria applied for treatment of acute carbon monoxide (CO) poisoning within the hyperbaric medicine community. Responses were received from 85% of the 208 facilities in the United States and Canada. Among responders, 89 monoplace and 58 multiplace chamber facilities treat acute CO poisoning, managing a total of 2,636 patients in 1992. A significant majority of facilities treat CO-exposed patients with coma (98%), transient loss of consciousness (LOC) (77%), ischemic changes on electrocardiogram (91%), focal neurologic deficits (94%), or abnormal psychometric testing (91%), regardless of carboxyhemoglobin (COHb) level. Although 92% would use HBO for a patient presenting with headache, nausea, and COHb 40%, only 62% of facilities utilize a specified minimum COHb level as the sole criterion for HBO therapy of an asymptomatic patient. When COHb is used as an independent criterion to determine HBO treatment, the level utilized varies widely between institutions. Half of responding facilities place limits on the delay to treatment for patients with only transient LOC. Time limits are applied less often in cases with persistent neurologic deficits. While variability exists, majority opinions can be derived for many patient selection criteria regarding the use of HBO in acute CO poisoning.
Carbon Monoxide Poisoning↗
Epidemic carbon monoxide poisoning following a winter storm.
Hospital emergency departments were surveyed to estimate the number of patients treated for carbon monoxide (CO) poisoning after a severe winter storm disrupted electrical service in western Washington State. At least 81 persons were treated. The two main sources of CO were charcoal briquettes (54% of cases) and gasoline-powered electrical generators (40% of cases). Of the 44 persons affected by CO from burning charcoal, 40 (91%) were members of ethnic minority groups; 27 did not speak English. All persons affected by CO from generators were non-Hispanic Whites. This was the largest epidemic of storm-related CO poisoning reported in the United States. This epidemic demonstrated the need to anticipate CO poisoning as a possible consequence of winter storms in cold climates and to make preventive messages understandable to the entire population at risk, including those persons who do not understand written or spoken English.
Adolescent↗
Emergency department visits for carbon monoxide poisoning in the Pacific Northwest.
This study was conducted to determine the annual number of emergency department (ED) visits and rate of hyperbaric oxygen (HBO2) treatment for carbon monoxide (CO) poisoning in Washington, Idaho, and Montana. All hospital emergency departments and hyperbaric treatment facilities in the region were surveyed by mail and telephone regarding their patient treatment experience for calendar year 1994. Results demonstrated that there were approximately 2.51 million total ED visits in 1994 in the three states studied. Among these, an estimated 1,325 individuals were seen with carbon monoxide poisoning (52.9 CO cases per 100,000 ED visits; 18.1 CO cases per 100,000 population). A total of 91 patients were treated with HBO2, yielding an HBO2 treatment rate of 6.9% of those evaluated in EDs. Extrapolating these figures to the US population suggests that the number of individuals seeking emergency medical care for CO poisoning is much greater than is commonly quoted. Even after correcting for the known increased rate of CO poisoning in the Pacific Northwest, the incidence of nonfatal poisoning appears to be significantly higher than may be appreciated from previous reports.
Carbon Monoxide Poisoning↗
Incidence of severe unintentional carbon monoxide poisoning differs across racial/ethnic categories.
OBJECTIVE: This study was conducted to test the hypothesis that the incidence of severe, acute, unintentional carbon monoxide (CO) poisoning differs across racial/ethnic categories. METHODS: The authors retrospectively reviewed medical records of all Washington State residents treated with hyperbaric oxygen for severe, acute, unintentional CO poisoning from December 1, 1987, through February 28, 1997. RESULTS: Among 586 Washington State residents treated with hyperbaric oxygen for severe, acute, unintentional CO poisoning, racial/ethnic designations could be determined from record review for 530 (90%). The black and Hispanic white populations of Washington State had higher relative risks for severe, acute, unintentional CO poisoning than the non-Hispanic white population. The most common sources of CO poisoning differed by racial/ethnic category. CONCLUSIONS: Members of certain groups in Washington State are at higher risk for severe, unintentional CO poisoning. Public education programs regarding CO exposure should be targeted to populations at risk.
Adolescent↗
Carbon monoxide poisoning in children riding in the back of pickup trucks.
OBJECTIVE - To describe the case characteristics of a series of children poisoned with carbon monoxide while traveling in the back of pickup trucks. DESIGN - Pediatric cases referred for treatment of carbon monoxide poisoning with hyperbaric oxygen between 1986 and 1991 were reviewed. Those cases that occurred during travel in the back of pickup trucks were selected. Clinical follow-up by telephone interview ranged from 2 to 55 months. SETTING - A private, urban, tertiary care center in Seattle, Wash. PATIENTS - Twenty children ranging from 4 to 16 years of age. INTERVENTION - All patients were treated with hyperbaric oxygen. MAIN OUTCOME MEASURES - Characteristics of the poisoning incident and clinical patient outcome. RESULTS - Of 68 pediatric patients treated for accidental carbon monoxide poisoning, 20 cases occurred as children rode in the back of pickup trucks. In 17 of these, the children were riding under a rigid closed canopy on the rear of the truck, while three episodes occurred as children rode beneath a tarpaulin. Average carboxyhemoglobin level on emergency department presentation was 18.2% +/- 2.4% (mean +/- SEM; range, 1.6% to 37.0%). Loss of consciousness occurred in 15 of the 20 children. One child died of cerebral edema, one had permanent neurologic deficits, and 18 had no recognizable sequelae related to the episode. In all cases, the truck exhaust system had a previously known leak or a tail pipe that exited at the rear rather than at the side of the pickup truck. CONCLUSIONS - Carbon monoxide poisoning is a significant hazard for children who ride in the back of pickup trucks. If possible, this practice should be avoided.
Adolescent↗
Hyperbaric treatment of patients with carbon monoxide poisoning in the United States.
INTRODUCTION: Hyperbaric oxygen (HBO2) is effective therapy for carbon monoxide (CO) poisoning. In recent years, many hyperbaric physicians in the US have felt that numbers of patients referred for treatment of CO poisoning have decreased. Further, since the 2002 Weaver et al study (5), there has been discussion regarding the best treatment protocol. This study was conducted to determine numbers of patients treated with HBO2 annually over the past decade in the US and whether there is a consensus about the number of treatments per patient. MATERIALS AND METHODS: A survey was mailed to all US facilities listed in the 2001 UHMS Chamber Directory. Two subsequent mailings were sent to survey nonresponders, followed by telephone contacts. RESULTS: Of the 320 facilities listed in the directory, 10 were nonresponders, 26 had closed since publication and 80 do not treat CO poisoning, leaving 204 facilities. From 1992-2002, a total of 16,367 patients were treated with HBO2 for CO poisoning, an average of 1,488 +/- 121 patients/year (mean < or = SD). While the total number of patients treated annually did not decrease during the period studied, the number treated per facility did decline as a result of an increase in number of treating facilities. Only 46 facilities (23%) automatically give more than 1 hyperbaric treatment per CO-poisoned patient. Among those that do, 20 facilities (10%) give 3 treatments per patient. Conversely, 136 (67%) sometimes give more than one treatment and 12 facilities (8%) never retreat. CONCLUSIONS: Approximately 1,500 CO-poisoned patients are treated with HBO2 in the US annually, a number that has remained relatively constant since 1992. The majority of facilities does not routinely give more than one hyperbaric treatment, but will give repetitive treatment in certain situations.
Carbon Monoxide Poisoning↗
A prospective, randomized clinical trial comparing two hyperbaric treatment protocols for carbon monoxide poisoning.
INTRODUCTION: The optimal hyperbaric oxygen (HBO2) treatment protocol for acute carbon monoxide (CO) poisoning is unknown. This is indicated by one study that found 18 different protocols to treat CO poisoning by North American multiplace hyperbaric facilities. A pilot study was conducted to evaluate the feasibility of randomizing patients to different protocols and to determine whether any large differences in clinical outcome were present between the two most common protocols. METHODS: Adult patients with accidental CO poisoning resulting in transient loss of consciousness, presentation to the emergency department within 12 hours, primary language English, high school education, and residence within 100 miles of the hyperbaric facility were recruited. Enrolled patients were randomized to one HBO2 treatment at 2.4 atmospheres absolute (atm abs) pressure with 90 minutes of 100% oxygen breathing vs. treatment by the US Air Force CO protocol (3.0 atm abs maximum pressure). A neurocognitive screening test was performed immediately after hyperbaric treatment and repeated 14-21 days later. RESULTS: From 1995 to 2002, 30 patients age 21 to 88 years were randomized, 18 to treatment at 2.4 atm abs and 12 to 3.0 atm abs. Average carboxyhemoglobin level for the population was 24.8 +/- 8.8% (mean +/- SD). Delay to hyperbaric treatment averaged 313 +/- 129 minutes. Neither variable was different between treatment groups. Six patients had abnormal neurocognitive testing immediately following hyperbaric treatment, 4 in the 2.4 atm abs group (22%) and 2 in the 3.0 atm abs group (17%) (P=0.71). One patient in each group demonstrated abnormality on delayed testing (p=0.75). One in each group did not return for follow-up. CONCLUSIONS: It is feasible to randomize CO-poisoned patients to different hyperbaric treatment protocols. Determination of differences in efficacy between treatment protocols will require a large multicenter trial with the use of detailed neurocognitive testing.
Adult↗
Storm-related carbon monoxide poisoning: lessons learned from recent epidemics.
Over the past 15 years, a number of epidemics of carbon monoxide (CO) poisoning related to various storms have been reported. While the geographical location of these outbreaks and the types of storms involved has been diverse, review of the events reveals a number of common factors and themes. This paper summarizes the details of 9 published reports describing CO poisoning associated with 11 different storms. When common patterns were examined, five "lessons to be learned" from the experience were derived. They are (1) loss of electrical power can lead indirectly to carbon monoxide poisoning, (2) campaigns to educate the public about risks for CO exposure should be timed regionally to coincide with the peak risk for typical storms, (3) significant opportunities exist for prevention of generator-related CO poisoning, (4) there is a window of time for effective communications regarding the dangers of CO poisoning even after a storm strikes, and (5) the major sources of CO responsible for poisonings can be related to the type of storm and are predictable. It is hoped that each of these lessons are used to develop public programs designed to prevent storm-associated CO poisoning in the future.
Carbon Monoxide Poisoning↗
Carbon monoxide poisoning among recreational boaters.
OBJECTIVE: To describe the case characteristics of a series of patients poisoned with carbon monoxide (CO) while boating for recreation. DESIGN: Cases of patients referred for treatment of CO poisoning with hyperbaric oxygen were reviewed. Those cases that occurred during recreational boating were selected for analysis. SETTING: A private, urban, tertiary care center studied from July 1984 to June 1994. PATIENTS: Thirty-nine patients ranging in age from 6 months to 69 years who were poisoned in 27 separate incidents. MAIN OUTCOME MEASURES: Characteristics of the poisoning incidents were assessed at initial patient presentation, immediately following treatment, and with follow-up telephone interviews. RESULTS: Of 512 patients treated for acute unintentional CO poisoning, 39 cases (8%) occurred in 27 incidents related to recreational boating activities. Individuals typically lost consciousness as a result of the poisoning. Most cases occurred aboard a boat that was older than 10 years, had an enclosable cabin, was longer than 22 feet, was powered by a gasoline engine, and was without a CO detector on board. CONCLUSIONS: Carbon monoxide poisoning is a serious hazard associated with recreational boating. The installation of CO detectors aboard boat types typically associated with this syndrome should be strongly encouraged.
Adolescent↗