Toxicological findings in fatally injured pilots of 979 amateur-built aircraft accidents.

BACKGROUND: Specimens from aviation accident pilot fatalities are submitted to the Civil Aerospace Medical Institute (CAMI) for toxicological analyses. Trends of fatal amateur-built aircraft accidents and toxicological findings in the associated pilot fatalities have not been examined. METHODS: Fatal amateur-built aircraft accidents that occurred during 1990-2009 were evaluated by retrieving information from the CAMI toxicology database. Probable cause/factor in the amateur-built aircraft mishaps were obtained from the National Transportation Safety Board's (NTSB's) aviation accident database. RESULTS: Of 6309 fatal aviation accidents from which CAMI received postmortem samples, 979 (16%) were related to amateur-built aircraft. There was a decreasing trend in non-amateur-built aircraft accidents, but an increasing trend in amateur-built aircraft accidents. In the 979 accidents, 392 pilots (40%) were positive for ethanol and/or drugs. In these 392 accidents also, the review showed a decreasing trend with non-amateur-built aircraft and an increasing trend with amateur-built aircraft. Percentages of pilots with prescription drugs were 26% for amateur-built aircraft, 16% for non-amateur-built aircraft, and 18% for all aircraft. Ethanol/drug use and medical condition were determined to be a cause/factor in 42 (11%) of the 385 ethanol/ drug-positive amateur-built aircraft accidents investigated by the NTSB. DISCUSSION: Drugs found in the pilots were consistent with commonly used medications in the general population. The contributory role of mechanical malfunction of home-built aircraft cannot be ruled out in the observed increasing trends in their accidents, with or without ethanol and/or drugs. Regardless, the increasing trends of such accidents are of significant concern.

The results of real-time brachytherapy for the management of low- and intermediate-risk prostate cancer in patients with prostate volumes up to 100 mL.

OBJECTIVES: • To report the results of real-time brachytherapy in the management of low-risk and intermediate-risk prostate cancer in patients with prostate volumes up to 100 mL, over a 6-year period. • To prospectively determine whether prostate volume influences the ability to achieve a quality implant and therefore impact upon prostate-specific antigen (PSA) relapse-free survival, and urinary and rectal toxicity. SUBJECTS AND METHODS: • In all, 216 men with localized prostate cancer were treated with real-time prostate brachytherapy using (125) I implants between November 2003 and December 2009. • Patient selection was based upon functional parameters; International Prostate Symptom Score (IPSS) and flowmetry. • Patients had computed tomography imaging at 1 month to assess post-implant dosimetry. PSA, IPSS and Radiation Therapy Oncology Group rectal toxicity scores were recorded prospectively over the follow-up period. • Patients with prostate volumes ≤50 mL and those with volumes >50 mL were compared. RESULTS: • Overall PSA relapse-free survival was 98.8%; 97.0% for intermediate-risk patients and 100.0% for low-risk patients. By volume, 98.5% of men with standard prostates were free from PSA relapse compared with 100.0% of men with large prostates. • The mean post-implant D90 was 177.0 Gy; 175.5 Gy in standard prostates and 183.5 Gy in large prostates. • The overall acute urinary retention rate was 1.9%; 1.7% in standard prostates and 2.4% in large prostates. There were three urethral strictures, all in the standard prostate group. The mean IPSS increased to 11 and 14 at 3 months for the standard and large prostate groups, respectively, before settling to 2 above baseline for both groups at 12 months. • There were no rectovesical fistulae. Persistent rectal bleeding was reported by one (0.5%) patient in the standard prostate group. CONCLUSIONS: • Prostate brachytherapy is effective in the treatment of low-risk and intermediate-risk prostate cancer. • It is technically possible to deliver a quality implant in a large prostate using real-time brachytherapy. • The treatment itself is well tolerated. Prostate volumes up to 100 mL should not exclude patients from brachytherapy providing either flow rate ≥14 mL/s or symptom score (IPSS) ≤ 10.

The FAA's postmortem forensic toxicology self-evaluated proficiency test program: the second seven years.

During toxicological evaluations of samples from fatally injured pilots involved in civil aviation accidents, a high degree of quality control/quality assurance (QC/QA) is maintained. Under this philosophy, the Federal Aviation Administration (FAA) started a forensic toxicology proficiency-testing (PT) program in July 1991. In continuation of the first seven years of the PT findings reported earlier, PT findings of the next seven years are summarized herein. Twenty-eight survey samples (12 urine, 9 blood, and 7 tissue homogenate) with/without alcohols/volatiles, drugs, and/or putrefactive amine(s) were submitted to an average of 31 laboratories, of which an average of 25 participants returned their results. Analytes in survey samples were correctly identified and quantitated by a large number of participants, but some false positives of concern were reported. It is anticipated that the FAA's PT program will continue to serve the forensic toxicology community through this important part of the QC/QA for laboratory accreditations.

Changing Practice Evaluation-Stage 1 Seminoma: Outcomes With Adjuvant Treatment Versus Surveillance: Risk Factors for Recurrence and Optimizing Follow-up Protocols-Experience From a Supraregional Center.

BACKGROUND: Stage 1 seminoma is frequently cured by radical orchiectomy; however, the management strategies after this diagnosis vary in terms of the use of adjuvant treatment and the nature of the follow-up protocols. We analyzed stage 1 seminomas treated in the Thames Valley Cancer Network for outcomes to determine whether any factors are predictive of recurrence. We also studied relapses to determine the optimal follow-up schedule and protocol. MATERIALS AND METHODS: Data were obtained from centers within the Thames Valley Cancer Network for a 12-year period from 2004 to 2016. We identified 501 patients with stage 1 seminoma. RESULTS: Relapses occurred in 6.2% of the patients receiving adjuvant treatment and 6.1% of those who did not. The only statistically significant predictive factor identified for relapse was rete testis invasion, and the risk was greater when only stromal rete invasion was included, rather than pagetoid as well. A trend was seen toward an increased risk with increased tumor size, but the difference was not statistically significant. Recurrences developed within the first 2 years after surgery in nearly 75% of cases and were identified through surveillance computed tomography scans in 54.8% of the patients. All relapses were treated curatively. CONCLUSION: Active surveillance leads to excellent outcomes for stage 1 seminoma; however, adjuvant treatment should be reserved for those with high-risk disease. Follow-up schedules should include computed tomography imaging during the first 3 years, long-term measurement of tumor markers, and mechanisms for patients to be seen promptly should symptoms of tumor recurrence occur.

Ethanol and Drugs Found in Civil Aviation Accident Pilot Fatalities, 1989-2013.

BACKGROUND: Biological specimens from pilots fatally injured in civil aviation accidents are analyzed for ethanol and drugs at the Civil Aerospace Medical Institute (CAMI). Prevalence of these substances in the pilots has been evaluated at 5-yr intervals since 1989. In continuation, a fifth 5-yr study (2009-2013) was conducted. METHODS: The CAMI toxicology/medical certification and National Transportation Safety Board (NTSB) aviation accident databases were searched. RESULTS: During 2009-2013, samples from 1169 pilots were analyzed. Aircraft involved in the accidents were primarily operating under general aviation. Most airmen were private pilots and held third-class medical certificates. In relation to the first 5-yr (1989-1993) period, the pilot fatality cases decreased by 37% and the presence of ethanol and/or drugs in the pilots increased by 239% in the fifth 5-yr period. The ethanol usage was unchanged, but increases were 267% and 583% with illicit and prescription drugs, respectively. The use of ethanol and/or drugs by aviators, along with underlying medical conditions, was determined by the NTSB to be cause/factors in 5% of the accidents. CONCLUSION: The observed decrease in the fatality cases does not necessarily suggest the decrease in aviation accidents, as active airmen numbers also declined. The increase in the drug positive cases is primarily attributed to the continuous rise in the use of prescription drugs. Although prevalence of ethanol and drugs has been evaluated in fatally injured aviators, such evaluation has not been performed in active pilots not involved in accidents. This type of comparative study would be crucial in assessing aviation safety.

The +Gz recovery of consciousness curve.

BACKGROUND: The limiting physiological envelope to extreme gravitational stress is defined by neurologic symptoms and signs that result from exceeding neurologic tolerance. The edge of the limiting envelope is defined by the complete incapacitation associated with acceleration (+Gz) induced loss of consciousness. Should + Gz-induced loss of consciousness occur in-flight, brisk recovery of conscious function is essential for aircraft recovery. If recovery does not occur, accident investigation aimed at preventing such accidents is enhanced by understanding the temporal aspects of the resulting incapacitation. The mechanistic basis of neurological reintegration leading to consciousness recovery is of broad medical and scientific interest. METHODS: Recovery of consciousness episodes from a prospectively developed +Gz-induced loss of consciousness repository of healthy individuals was analyzed to define variables influencing recovery of consciousness. The time from loss to recovery of consciousness as measured by observable signs, is defined as the absolute incapacitation period. The absolute incapacitation period from 760 episodes of loss and recovery of consciousness in healthy humans was analyzed to define +Gz-profile variables that determine the duration of functional neurologic compromise. RESULTS: Mean time from loss to return of consciousness for 760 episodes of consciousness recovery was 10.4 ± 5.1 s; minimum 1 s; maximum 38 s. Offset rate for the +Gz-exposure deceleration profiles varied from a minimum of 0.17 Gs(-1) to a maximum of 7.93 Gs(-1).The curve produced by plotting +Gz-offset rate (Gs(-1); y) versus absolute incapacitation period (s; x) described a hyperbolic relationship. The hyperbolic relationship indicates there is a minimum time (mean 8.29 ± 3.84 s) required for recovery of consciousness when complete loss of consciousness occurs. CONCLUSIONS: Mean recovery time from +Gz-induced unconsciousness is dependent on the deceleration profile's offset rate from the point of loss of consciousness. This relationship is described by a curve plotting offset rate and time for recovery of consciousness. This curve predicts when conscious function should return following exposure to +Gz stress sufficient to cause unconsciousness. The maximum +Gz level of the recovery exposure profile was found to be inadequate for predicting variations in the time for recovery of consciousness.

Increased cannabinoids concentrations found in specimens from fatal aviation accidents between 1997 and 2006.

The National Institute on Drug Abuse (NIDA) and the Office of National Drug Control Policy (ONDCP) reported a 1.5-fold increase in the delta-9-tetrahydrocannabinol (THC) content of street cannabis seizures from 1997 to 2001 versus 2002 to 2006. This study was conducted to compare the changes, over those years, in blood and urine cannabinoid concentrations with the potency of THC reported in the cannabis plant. Cannabinoids were screened using radioimmunoassay (RIA) for blood and fluorescence polarization immunoassay (FPIA) for urine and confirmed using GC/MS. A total of 95 individuals were found to be using cannabis from a total number of 2769 (3.4%) individuals tested over the period 1997 through 2006. Other impairing drugs were found in 38% of the cannabinoids-positive individuals. The mean concentration of THC in blood for 1997-2001 was 2.7 ng/mL; for 2002-2006, it was 7.2 ng/mL, a 2.7-fold increase in the mean THC concentration of specimens from aviation fatalities, compared to a 1.5-fold increase in cannabis potency reported by the NIDA and ONDCP. The mean age for cannabis users was 40 years (range 18-72) for aviation fatalities. For all blood and urine specimens testing negative for cannabinoids from aviation fatalities, the mean age of the individuals was 50 years (range 14-92). More than half of the fatalities tested were 50 years or older, whereas, 80% of the positive cannabis users were under 50. As indicated by these findings, members of the transportation industry, government regulators, and the general public should be made aware of the increased potential for impairment from the use of high-potency cannabis currently available and being used.