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Anthony N Nicholson

Publications and source records attributed to Anthony N Nicholson.

10 recordsLinked to original sources
PubMed2006

Sleep and intercontinental flights.

At present there are no 'high-tech' solutions to the problems that may beset intercontinental travellers. Indications for the use of drugs are limited, and their use must accord with Good Clinical Practice. Essentially, travellers must look after their sleep, as far as possible, during and after the flight. The most useful time for sleep during the flight must be anticipated, caution exercised in the use of hypnotics in-flight as reduced mobility is a potential risk factor for venous thrombosis, and a strategy adopted, whether flying east or west, to adapt as quickly as possible to the working hours of the new locality. After an eastward flight a hypnotic may be useful, but this strategy is seldom necessary after a westward flight unless the journey has involved crossing more than 5 or 6 time zones. The claim that melatonin accelerates the shift of the sleep-wakefulness cycle to a new time zone is controversial, and its recommended use may prejudice alertness during working hours. Exposure to artificial light and avoidance of ambient light at certain times of the day could prove to be of help-possibly in conjunction with drugs. However, effective and practical alterations in the light environment must be devised before such strategies can be considered with confidence.

Aircraft↗
PubMed2006

Sedation and memory: studies with a histamine H-1 receptor antagonist.

The influence of sedation on the effect of an H-1 receptor antagonist on various cognitive functions, including memory, were evaluated. Diphenhydramine (50, 75 and 100 mg) and lorazepam (0.5 and 1.5 mg) were given on single occasions to 12 healthy volunteers (six males, six females) aged 20-33 (mean 23.4) years. Subjective assessments of sedation, sleep latencies, digit symbol substitution, choice reaction time, sustained attention and memory recall were studied 1.0 h before and 0.5, 2.0 and 3.5 h after drug ingestion. The study was double blind, placebo controlled and with a crossover design. With all doses of diphenhydramine there was subjective sedation, reduced sleep latencies and impairments in performance on the digit symbol substitution, choice reaction time and sustained attention tasks. No effects were observed with 0.5 mg lorazepam. With 1.5 mg lorazepam there was subjective sedation, fewer digit symbol substitutions, slowed choice reaction time, impaired attention and memory, but no effect on sleep latencies. Contrast analysis of data measured at all time points showed that although there was no difference in the effect of diphenhydramine (100 mg) and lorazepam (1.5 mg) on those tasks without a memory component, response times were slower with lorazepam on those tasks with a memory component. However, both 100 mg diphenhydramine and 1.5 mg lorazepam impaired prompted recall measured at 2 h post-ingestion only. It is considered that impaired memory is not necessarily associated with sedation, and that impairment of memory with drugs that lead to sedation may be effected through neuronal systems independent of those that affect arousal.

Adult↗
PubMed2006

Aircrew and type 1 diabetes mellitus.

The most stringent clinical criteria cannot guarantee that individuals with Type 1 diabetes mellitus (DM) will preserve awareness of an impending hypoglycemic episode or that a hypoglycemic episode can be prevented. Further, cognition may be impaired for a considerable period of time beyond the correction of any episode. These observations and their implications to operational aircrew with Type 1 DM are discussed.

Aerospace Medicine↗
PubMed2005

Anti-diuretic for operational aircrew: effects of desmopressin on urine flow, cognition, and sleepiness.

INTRODUCTION: Air operations may demand missions of many hours, and aircrew may experience significant discomfort due to bladder distension. Attention has been given to the use of in-flight urination devices, but an alternative strategy could be reduction of urine flow by an anti-diuretic. In this event it would be important to establish an effective dose range free of adverse effects. METHODS: The effects of desmopressin (0.05, 0.10, 0.15, and 0.20 mg) on cognitive performance and sleepiness (multiple sleep latency test) from 1 to 11 h, and on urine flow up to 24 h after drug ingestion at 09:00, were studied in 20 healthy young volunteers. The study was double blind, placebo controlled, and with a randomized five-way crossover design. RESULTS: There was no evidence of impaired performance with desmopressin at or below 0.15 mg. All doses reduced urine flow up to 12 h after drug ingestion (p < 0.001), and the reduction appeared to be maximal at 0.10 mg. The dose range was free of adverse effects, except for the possibility of headaches, but they are unlikely to be of operational significance. DISCUSSION: Desmopressin could prove to be a significant advance in the management of urinary flow in operational aircrew. The dose could be as low as 0.05 mg with the option to use 0.10 mg in those less sensitive to the drug. Individual experience of the effect of the drug would be appropriate before use in flight, and guidelines concerning fluid intake would be needed. Further information may be required for use of the drug overnight.

Adult↗
PubMed2004

Effect of Delta-9-tetrahydrocannabinol and cannabidiol on nocturnal sleep and early-morning behavior in young adults.

The effects of cannabis extracts on nocturnal sleep, early-morning performance, memory, and sleepiness were studied in 8 healthy volunteers (4 males, 4 females; 21 to 34 years). The study was double-blind and placebo-controlled with a 4-way crossover design. The 4 treatments were placebo, 15 mg Delta-9-tetrahydrocannabinol (THC), 5 mg THC combined with 5 mg cannabidiol (CBD), and 15 mg THC combined with 15 mg CBD. These were formulated in 50:50 ethanol to propylene glycol and administered using an oromucosal spray during a 30-minute period from 10 pm. The electroencephalogram was recorded during the sleep period (11 pm to 7 am). Performance, sleep latency, and subjective assessments of sleepiness and mood were measured from 8:30 am (10 hours after drug administration). There were no effects of 15 mg THC on nocturnal sleep. With the concomitant administration of the drugs (5 mg THC and 5 mg CBD to 15 mg THC and 15 mg CBD), there was a decrease in stage 3 sleep, and with the higher dose combination, wakefulness was increased. The next day, with 15 mg THC, memory was impaired, sleep latency was reduced, and the subjects reported increased sleepiness and changes in mood. With the lower dose combination, reaction time was faster on the digit recall task, and with the higher dose combination, subjects reported increased sleepiness and changes in mood. Fifteen milligrams THC would appear to be sedative, while 15 mg CBD appears to have alerting properties as it increased awake activity during sleep and counteracted the residual sedative activity of 15 mg THC.

Adult↗
PubMed2003

Studies on performance and sleepiness with the H1-antihistamine, desloratadine.

INTRODUCTION: The purpose of this study was to establish whether the H1-antihistamine desloratadine (5 mg), the active metabolite of loratadine, is free of effects on performance and sleepiness. METHOD: Effects of desloratadine (5 mg) on psychomotor performance, daytime sleep latencies, subjective sleepiness, and memory were studied in nine healthy volunteers (four men, five women) between the ages of 20 and 39 yr (mean 28.2). Assessments were made 1.0 h pre-ingestion and from 0.5 to 8.0 h post-ingestion. The study was placebo-controlled and double blind with a crossover design, using promethazine (25 mg) as an active control. RESULTS: Promethazine impaired tracking (3.5-5.5 h), choice reaction time (3.5-5.5 h), digit symbol substitution (3.5-5.5 h), and attention (2.0-5.5 h). There was increased objective and subjective sleepiness (2.0-5.5 h) and subjective fatigue (3.5-8.0 h). There were no changes in any of these measures with desloratadine (5 mg). With promethazine, memory was impaired from 2.0-5.0 h. Analysis failed to establish a consistent effect on memory with desloratadine, as there was a change in only one (digit memory recall reaction time) of the twelve memory test measures at only one time point (5.5 h). The change was significant with respect to placebo, but not with respect to the pre-ingestion value. CONCLUSIONS: Desloratadine (5 mg) appears to be free of adverse effects on psychomotor performance, daytime sleep latencies, and subjective sleepiness, and could prove suitable for those involved in skilled activity and transportation.

Adult↗
PubMed2002

Central effects of cinnarizine: restricted use in aircrew.

HYPOTHESIS: Our aim was to establish the effects of cinnarizine, a drug used for the treatment of motion sickness, on daytime sleepiness and performance. METHODS: The effects of cinnarizine (15, 30, and 45 mg) were assessed on digit symbol substitution, tracking, vigilance, and on subjective and objective (daytime sleep latencies) sleepiness in six healthy volunteers between the ages of 20 and 34 yr (mean 27 yr) from 1.0 h prior to ingestion to 8.0 h after ingestion. The study was placebo-controlled and double-blind in a six-way, cross-over design. Promethazine (10 mg) was used as an active control. RESULTS: No effects of 15 mg cinnarizine were observed on performance. Sleep latencies were reduced at 3.5 and 5.0 h after ingestion, and the subjects as a group reported increased sleepiness at 5.0 and 6.5 h after ingestion. With 30 mg cinnarizine there was evidence of impaired performance at 5.0, 6.5, and 8.0 h after ingestion. Sleep latencies were not reduced, but the subjects as a group reported increased sleepiness 5.0 h after ingestion. With 45 mg cinnarizine there was evidence of impaired performance 5.0 h after ingestion. Sleep latencies were reduced at 5.0 and 6.5 h after ingestion, and the subjects as a group reported increased sleepiness 6.5 h after ingestion. Promethazine (10 mg) shortened sleep latencies from 2.5 to 5.0 h after ingestion, and the subjects as a group reported increased sleepiness overthis period. CONCLUSION: Cinnarizine is not free of central activity over the usual therapeutic dose range of 15 to 30 mg. It is contraindicated for motion sickness in aircrew involved in the control of aircraft. Caution should be exercised in the use of the drug by other aircrew who may be involved in tasks which demand continued attention.

Adult↗
PubMedDate not supplied

Confidential reporting: from aviation to clinical medicine.

The spectacular nature of accidents involving aircraft has obliged the aviation industry to introduce a process of confidential reporting to identify situations that may lead to poor work or even an accident. The information so gathered can then be used to reduce the likelihood of such problems occurring. Confidential reporting allows an individual to bring information relevant to safety to the attention of a body that is completely independent of management. They can be assured that their identity will remain confidential to that body. It is, as far as the individual is concerned, a confidential but not an anonymous procedure, which will be subjected to careful scrutiny. Confidentiality and independence from management are the essential features. The introduction of such a programme into the NHS would materially enhance its safety profile.

Accidents, Aviation↗
PubMedDate not supplied

Limitations of risk analysis in the determination of medical factors in road vehicle accidents.

The purpose of risk analysis in the determination of medical factors in road vehicle accidents is to evaluate the risks that are associated with different strategies for accident reduction, so that the subsequent decision making process can be based on a best assessment of the likely benefits. However, it is vital to appreciate the limitations of such an approach, especially where the conclusions depend heavily on the accuracy of the assumptions made. In this paper the assumptions used in some recent analyses concerned with incapacitation, epilepsy, hypoglycaemia and psycho-active medication are explored, and the additional information required to reduce the uncertainty in the estimation of risk indicated. The conclusions from this analysis do not invalidate the use of risk assessment, but draw attention to its limitations and show how a sensitivity analysis can help to identify those areas where more precise information is needed before such an approach can be used confidently in a policy setting.

Accidents, Traffic↗