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Neil B Hampson

Publications and source records attributed to Neil B Hampson.

18 recordsLinked to original sources
PubMed2006

Carboxyhemoglobin measurement by hospitals: implications for the diagnosis of carbon monoxide poisoning.

Most case definitions for carbon monoxide (CO) poisoning include demonstration of an elevated blood carboxyhemoglobin (COHb) concentration. Further, it is generally believed that treatment of CO poisoning is more effective when performed as soon as possible after the exposure. This suggests that a hospital's inability to measure blood COHb could lead to delayed or missed diagnosis or treatment. This study evaluated the ability of hospitals in the Pacific Northwest to measure COHb levels. The clinical laboratory of every acute care hospital in Washington, Idaho, Montana, and Alaska was surveyed regarding the ability to measure COHb levels, the method utilized and the time required. If they could not measure COHb, they were asked whether samples are sent elsewhere, the location of the referral laboratory, and time required. Results were then compared to the list of hospitals referring CO-poisoned patients to a regional center for hyperbaric oxygen therapy from 2003-2004. In the four states, only 44% of acute care hospitals have the capability to measure COHb. The remaining 56% send blood samples to other laboratories. The average time to get a result is 10 +/- 10 min in hospitals with co-oximetry and 904 +/- 1360 min in those without, a difference of 15 h (p < 0.0001). When samples are sent out, the average distance is 121 miles, often bypassing a hospital with CO-oximetry capability. Over 90% of CO-poisoned patients referred for hyperbaric treatment came from hospitals able to measure COHb. Fewer than one-half of acute care hospitals in a four-state region have the capability to measure COHb levels. This has the potential to significantly impact diagnosis or treatment of patients with acute CO poisoning.

Alaska↗
PubMed2006

Hyperbaric oxygen therapy for radiation induced proctopathy in men treated for prostate cancer.

PURPOSE: Radiation proctitis is a common complication following external beam radiation therapy and brachytherapy for prostate cancer. While 95% percent of radiation induced proctitis is temporary and self-limiting, up to 5% of patients experience toxicities that are refractory to conservative management. Hyperbaric oxygen has a well-defined role in treating chronic wounds, osteomyelitis, hemorrhagic cystitis and necrotizing fasciitis. We reviewed our experience with hyperbaric oxygen therapy for radiation induced proctitis in patients undergoing radiation treatment for prostate cancer. MATERIALS AND METHODS: From October 1998 to December 2003, 27 patients with radiation induced proctitis secondary to brachytherapy (4), external beam radiation therapy (16) or combined modality (7) for prostate cancer were treated with hyperbaric oxygen therapy at Virginia Mason Medical Center in Seattle, Washington. In all patients primary medical or endoscopic management had failed. Patients received 100% oxygen in a multiplace hyperbaric chamber at a pressure of 2.4 atmospheres absolute for 90 minutes 5 to 7 days weekly for an average of 36 sessions (range 29 to 60). Data were collected from a retrospective review of medical records following approval by the Institutional Review Board at Virginia Mason Medical Center. RESULTS: All 27 men completed the planned course of therapy. Of patients with bleeding 48% showed complete resolution after therapy, while 28% reported significantly fewer bleeding episodes. Of patients 50% noted complete resolution of fecal urgency. Six of the 8 patients (75%) with pain noticed some improvement after therapy, although no patients reported complete resolution of rectal pain. Of patients with rectal ulceration 21% showed complete resolution of the ulcer on posttreatment endoscopy, while 29% showed evidence of improvement. Six patients (43%) had no change or worsening of rectal ulcers. Overall 67% of patients had a partial to good response, while 33% showed no response or disease progression. CONCLUSIONS: This series of patients showed a good overall response rate to hyperbaric oxygen for radiation induced proctopathy after other attempts at management had failed. Hyperbaric oxygen is generally well tolerated and it remains an important treatment option for managing this common and difficult disease.

Aged↗
PubMed2006

Use of a noninvasive pulse CO-oximeter to measure blood carboxyhemoglobin levels in bingo players.

BACKGROUND: Though smokers are known to have elevated blood carboxyhemoglobin (COHb), due to inhalation of carbon monoxide (CO) in cigarette smoke, limited data exist regarding COHb levels in nonsmokers exposed to secondhand smoke. METHODS: COHb was measured using a new noninvasive pulse CO-oximeter (Rad-57, Masimo, Irvine, California) in 38 subjects entering a bingo hall where smoking was allowed, then again as they exited 3 hours later. RESULTS: The mean +/- SD baseline COHb for the entire group was 3.3 +/- 1.8%, for the 23 nonsmokers it was 2.2 +/- 0.7%, and for the 15 smokers it was 4.9 +/- 1.9%. The nonsmokers' mean COHb was unchanged, at 2.2 +/- 0.8%, whereas the smokers' mean COHb fell to 3.2 +/- 1.9%. CONCLUSIONS: The nonsmokers were not significantly exposed to CO from secondhand smoke in the setting we tested. The smokers probably consumed fewer cigarettes while playing bingo than they did prior to arrival. The Rad-57 pulse CO-oximeter is easy to use in the ambulatory setting.

Blood Gas Monitoring, Transcutaneous↗
PubMed2005

Trends in the incidence of carbon monoxide poisoning in the United States.

PURPOSE: Recent data demonstrate that the mortality rate from carbon monoxide poisoning has declined over the past 2 decades. It is not known whether this decrease in mortality is reflective of the total burden of carbon monoxide poisoning. This study sought to examine trends in other potential indicators of the incidence of carbon monoxide poisoning in the United States. BASIC PROCEDURES: Published data from US poison control centers (PCCs) were used to calculate annual rates of calls regarding carbon monoxide exposures. Data on numbers of carbon monoxide-poisoned patients treated with hyperbaric oxygen (HBO) were used to calculate annual treatment rates. Trends in rates of carbon monoxide-related mortality, calls to PCCs, and HBO treatment were then compared. MAIN FINDINGS: Contrary to the decline in carbon monoxide-related mortality from 1968 to 1998, rates of calls to PCCs significantly increased over the same period. Neither rates of PCC calls nor HBO treatment changed significantly from 1992 to 2002. The latter 2 measures were strongly correlated. PRINCIPAL CONCLUSIONS: Although deaths from carbon monoxide poisoning have clearly decreased in the United States, other indicators of the incidence of the condition suggest that the total burden (fatal and nonfatal) may not have significantly changed. Efforts to prevent carbon monoxide poisoning should not be relaxed.

Carbon Monoxide Poisoning↗
PubMed2005

Carbon monoxide poisoning from portable electric generators.

BACKGROUND: While the overall death rate from unintentional carbon monoxide (CO) poisoning has decreased in the United States due to improved automobile emissions controls and a decline in CO poisonings from motor vehicles, exposures have not changed from some sources of CO. One of these is the operation of portable electrical generators in poorly ventilated spaces. This study sought to describe the population poisoned from CO produced by portable electric generators, and to determine the reasons that generators are operated in a hazardous fashion. METHODS: Cases of CO poisoning referred for treatment with hyperbaric oxygen at Virginia Mason Medical Center in Seattle from November 1978 to March 2004 were reviewed. Those cases that resulted from portable generator use were selected for analysis. RESULTS: Sixty-three patients aged 2 to 85 years were treated for CO poisoning from portable electric generators. They included 34 males and 29 females who were poisoned in 37 separate incidents. Thirty-four lost consciousness with the exposure. Of the 63 total patients, 60 spoke English. Generators were typically used when normal electrical service was disrupted by a storm or in remote locations. In 29 of 37 incidents, the generator was operated in the home environment, most commonly in the garage. Lack of awareness of the dangers of CO poisoning or lack of knowledge of ventilation requirements were the most commonly identified reasons. CONCLUSIONS: CO poisoning from portable electric generators occurs in a characteristic population, in a few typical locations and for a limited number of reasons. This information may help target prevention efforts for this form of poisoning, such as warning labels or educational programs.

Accidents, Home↗
PubMed2005

Early hyperbaric oxygen therapy improves outcome for radiation-induced hemorrhagic cystitis.

OBJECTIVES: To assess the clinical factors that affect the efficacy of hyperbaric oxygen (HBO2) therapy in treating radiation-induced hemorrhagic cystitis. HBO2 therapy is an effective treatment for radiation-induced hemorrhagic cystitis, with reported response rates ranging from 76% to 100%. METHODS: The data from patients with radiation-induced hemorrhagic cystitis treated at our institution between May 1988 and December 2001 were reviewed retrospectively. All patients received HBO2 therapy at 2.36 atm absolute pressure, with 90 minutes of 100% oxygen breathing per treatment. The outcome was assessed after at least 12 months of follow-up. We evaluated patient demographics, types of pelvic malignancy and radiotherapy, total radiation dose, onset and severity of hematuria, and prior intravesical management. Clinical improvement was defined as the absence of, or reduction in, macroscopic hematuria. RESULTS: A total of 60 patients (55 men and 5 women), mean age 70 years, received an average of 33 HBO2 treatments (range 9 to 63). Of the 60 patients, 48 (80%) had either total or partial resolution of hematuria. When treated within 6 months of hematuria onset, 96% (27 of 28) had complete or partial symptomatic resolution (P = 0.003). All 11 patients with previous clot retention had clinical improvement if treated within 6 months of hematuria onset (P = 0.007). Prior intravesical chemical instillation did not affect the clinical outcome. Patients who had undergone primary, adjuvant, or salvage external beam pelvic radiotherapy showed response rates of 81%, 83%, and 78%, respectively (P = 0.950). CONCLUSIONS: Our results show that delivery of HBO2 therapy within 6 months of hematuria onset is associated with a greater therapeutic response rate. Treatment efficacy was independent of prior intravesical therapy and the timing of radiotherapy.

Adolescent↗
PubMed2005

Partial seizure provoked by hyperbaric oxygen therapy: possible mechanisms and implications.

Hyperbaric oxygen treatment (HBO2) is used commonly for treatment of bone and soft-tissue radiation necrosis. It may be a potential therapy for radiation necrosis seen after brain irradiation. HBO2 risks include generalized tonic-clonic convulsions. We report a patient after resection of anaplastic astrocytoma and 5,580 cGy of total external-beam radiation treatments with brain radiation necrosis who underwent HBO2 therapy and developed a partial seizure during treatment. Mechanisms and implications are discussed.

Astrocytoma↗
PubMed2004

Hyperbaric oxygen does not accelerate latent in vivo prostate cancer: implications for the treatment of radiation-induced haemorrhagic cystitis.

OBJECTIVE: To assess the effects of hyperbaric oxygen (HBO2; often used to treat haemorrhagic cystitis, a known side-effect after radiation therapy for prostate cancer and with the potential to induce tumour angiogenesis and stimulate latent recurrence) on indolent in vivo prostate cancer in a murine model. MATERIALS AND METHODS: Human prostate LNCaP cells were injected into 60 severe combined-immunodeficient mice; of these 24 (40%) did not develop palpable tumours after 6 weeks. They were randomized to undergo 20 sessions of either HBO2 or normobaric air in standardized conditions, and observed for another 4 weeks before the histological assessment of any palpable tumours that developed. Analysis of developed LNCaP tumours included tumour volume, microvessel density, MIB-1, p53, p27 and racemase staining intensity. RESULTS: HBO2 was associated with less prostate tumour progression than normobaric air (P = 0.26). During HBO2 therapy, 10 mice remained free of palpable tumours, compared with seven controls (P = 0.30). On evaluation during the 4 weeks after therapy, six mice treated with HBO2 remained free of palpable tumours, vs eight of the controls (P = 0.17). There was tumour invasion and necrosis in a two of six and four of the HBO2 group during and after therapy, respectively, vs five and seven of the controls. Tumour microvessel density, proliferative index, differentiation and apoptosis markers were similar in both groups. CONCLUSIONS: HBO2 does not accelerate the growth of indolent prostate cancer in a murine model, suggesting that it does not increase the risk of residual prostate cancer reactivation when it is used to manage radiation-induced haemorrhagic cystitis in patients treated by pelvic radiotherapy for prostate cancer.

Animals↗
PubMed2003

Treatment of radiation induced hemorrhagic cystitis with hyperbaric oxygen.

PURPOSE: Hemorrhagic cystitis can occur 6 months to 10 years after pelvic radiation therapy with moderate to severe persistent rates of hematuria as 3% to 5% after radiotherapy for pelvic malignancies. Current treatment modalities for hemorrhagic cystitis include oral and intravenous agents, intravesical therapy and selective embolization of the hypogastric arteries. Hyperbaric oxygen therapy is now a widely accepted treatment option for radiation induced hemorrhagic cystitis. We assess the efficacy of hyperbaric oxygen for treatment of hemorrhagic cystitis. MATERIAL AND METHODS: From May 1988 through March 2001, 62 patients with radiation induced hemorrhagic cystitis were treated with hyperbaric oxygen at our institution. Followup ranged from 10 to 120 months. The primary pathological conditions were prostate cancer (81%) and bladder cancer (10%). Mean patient age was 70 years (range 15 to 88). Mean time between completion of radiation therapy and onset of hematuria was 48 months (range 0 to 355). Patients received an average of 33 hyperbaric oxygen treatments (range 9 to 68). RESULTS: Of the 62 patients treated information on 57 was available for analysis. Of the 57 patients (86%) 49 experienced complete resolution or marked improvement of hematuria following hyperbaric oxygen treatment. Of the 8 patients who did not improve 4 received fewer than 40 hyperbaric oxygen treatments and 7 prematurely terminated treatment (medical co-morbidities 4, claustrophobia 2, temporary resolution of symptoms 1). CONCLUSIONS: Hyperbaric oxygen therapy for radiation induced hemorrhagic cystitis is an efficacious treatment modality for patients in whom other forms of management have failed.

Adolescent↗
PubMed2002

Characteristics of headache associated with acute carbon monoxide poisoning.

OBJECTIVE: To evaluate systematically the characteristics of headache due to acute exposure to carbon monoxide. BACKGROUND: Headache is the most commonly reported symptom in acute carbon monoxide poisoning. While it is often described as throbbing and diffuse, a systematic characterization of carbon monoxide-associated headache has never been published. METHODS: Patients referred for hyperbaric oxygen treatment of acute carbon monoxide poisoning were asked whether headache was part of their symptom complex. When present, specific details about the nature of the headache were collected from 100 consecutive patients through use of a standardized questionnaire. RESULTS: Information on carbon monoxide-associated headache was collected from 34 female and 66 male patients with a mean carboxyhemoglobin level of 21.3%+/- 9.3%. The most common location for pain was frontal (66%), although more than one location was involved in 58% of patients. Nature of the pain at any time during its course was dull in 72% of patients and sharp in 36%. Headache was throbbing in 41%, continuous in 74%, and intermittent in 16% of those evaluated. Peak intensity of pain did not correlate with the carboxyhemoglobin level. Headache improved prior to hyperbaric oxygen treatment in 72%, resolving entirely in 21%. Of those with residual headache, pain improved with hyperbaric oxygen in 97%, resolving entirely in 44%. CONCLUSION: The headache accompanying acute carbon monoxide poisoning is extremely variable in nature. "Classic" throbbing, diffuse headaches were rarely described by patients. There are no patterns which can be considered characteristic to aid in the diagnosis of carbon monoxide-induced headache. Similarly, no trait was identified which might allow elimination of carbon monoxide poisoning from the differential diagnosis of headache.

Adolescent↗
PubMed2002

Effects of hyperbaric exposure on the integrity of the internal components of commercially available cochlear implant systems.

HYPOTHESIS: This study investigated whether pressure changes common to scuba diving and to hyperbaric oxygen therapy would not cause crush damage or leakage from critical seals in commercially available cochlear implants. BACKGROUND: The implanted packages of cochlear implants are susceptible to electrical failure caused by leakage from critical seals and to crush injury when exposed to changing barometric pressures encountered in recreational diving and in hyperbaric oxygen therapy. METHODS: Six Clarion 1.2, eight MED-EL Combi-40+, six Nucleus CI22M, and six Nucleus CI24M cochlear implants underwent three exposures at 165 feet of seawater (FSW) (6 ata abs), 99 FSW (4 ata abs), and 60 FSW (2.8 ata abs), simulating rates in accordance with U.S. Navy dive tables for nondecompression dives. Dives to 45 FSW (2.4 ata abs) simulated wound therapy. Before each dive began, after each dive, and after completion of the dive protocol, each device underwent telemetry and electrical integrity checks. All implants were returned to their respective factories for final electrical and quality control testing. RESULTS: All 26 devices completed the dive protocol. One Nucleus CI24M implant had a fault recorded at electrode lead 18 on predive and final product testing, which was absent during interval dive measurements. All 26 devices passed final electrical and quality control testing. In addition, the six Clarion units passed repeat helium leak testing. CONCLUSION: The implanted components of the Clarion 1.2, MED-EL Combi-40+, and Nucleus CI22M and CI24M were safely subjected to repeated pressure changes up to 6 atm abs, equivalent to 165 feet of seawater, without electrical failure from leakage at critical seals or crush damage.

Cochlear Implants↗