RxPG News : Anaethesia

Anaesthesia not harmful for babies during birth

Tue, 28 Jul 2009 13:08:33 PST

( from http://www.rxpgnews.com ) Babies exposed to anaesthesia during caesarean deliveries are not at any higher risk of developing learning disabilities than children delivered normally.

'We found that the incidence of learning disabilities was equal between children who were delivered vaginally and those who were delivered via C-section but with general anaesthesia,' says Juraj Sprung, Mayo Clinic anaesthesiologist who led the study.

'It's reassuring that the anaesthetics required for caesarean delivery do not appear to cause long-term brain problems,' Sprung adds.

The study was conducted with data from the Rochester Epidemiology Project. Researchers analysed the medical records of 5,320 children born between 1976 and 1982 to mothers living in Olmsted County.

They compared birth records with scholastic achievement and IQ tests administered to the children later in life as part of their schooling.

The study builds on a previous project, reported in March, which found that children exposed to a single dose of anaesthesia during the first three years of life had no increased risk for learning disabilities, but those exposed multiple times had an almost doubled risk of learning disabilities.

Prolonged exposure to anaesthetics has been shown to cause brain abnormalities in young animals, which was the impetus behind these two studies.

Not only did the researchers find that the use of anaesthesia during delivery was not harmful to the baby, they found that babies delivered by caesarean using an epidural anaesthetic - had a substantially reduced risk for learning disabilities later in life.

'The risk was reduced by about 40 percent compared to children delivered vaginally and those delivered via caesarean section but with general anaesthesia,' says Sprung, according to a Mayo Clinic release.

Study co-author and Mayo Clinic anaesthesiologist Randall Flick cautions that because

this study is preliminary, changes to medical practice should not be considered at this point. 'What we've found is an association between two things,' he says.

These findings are reported in the current issue of Anaesthesiology.

Increased suggestibility may help in pain-relieving effects of nitrous oxide

Sat, 10 Jan 2009 08:50:34 PST

( from http://www.rxpgnews.com ) The pain-relieving effects of nitrous oxide i.e. laughing gas, may be enhanced by suggestion or hypnosis, according to a new study by UCL (University College London). The study’s findings – that people are more suggestible under the gas – mean that dental patients may benefit from being coached to relax while undergoing sedation.
Nitrous oxide (laughing gas) is commonly used by dentists to sedate their patients before treatment, but some dentists believe their patients also become more suggestible while under the influence of the gas. A number of dentists have been trained in hypnosis and find that their patients respond well to being spoken to in a quiet, hypnotic manner – the new findings suggest that these effects could be further enhanced with laughing gas.
The UCL study set out to establish whether laughing gas does indeed boost imaginative suggestibility – a trait closely related to hypnotic suggestibility - and imagery vividness. Thirty participants took part in two sessions where they were given a mask from which they breathed in air or 25 per cent nitrous oxide. The volunteers were not told which type of gas they were being given, and the mask was scented to disguise the sweet smell of the laughing gas.
During each session, participants were given a series of mental imagery tests and were asked to rate their response according to a scale of 1-7, where 1 was ‘as clear and vivid as the real thing’ and 7 was ‘no image present at all’. For example, participants were asked to close their eyes and imagine tasting oranges or smelling roast beef, feeling linen or hearing the honk of a car horn.
Volunteers were also put through a series of ‘imaginative suggestibility’ tests based on suggestions given to them while under the gas. The suggestions were worded to invite the participant to experience hallucinated sensations. For example, they were told to imagine a sour taste in their mouth, and were told that after a while they would actually begin to experience a sour taste in their mouth, and that this would become stronger and stronger. Or they were told that a voice would come out of a (non-existent) speaker in the corner of the room, and that the voice would ask them a number of simple questions about themselves. If the participant responded well to the suggestion, he/she would answer some of the questions that the hallucinated voice had asked.
The study, published online in the journal Psychopharmacology, found that the nitrous oxide boosted imaginative suggestibility by approximately 10 per cent. This effect was unrelated to participants’ expectations regarding the effects of the drug.
Dr Matthew Whalley, Honorary Research Fellow at UCL, says: “Nitrous oxide is one of the most widely used yet least well understood anaesthetic gases and until recently, relatively little was known about how it worked inside the body. Recent research has shown that nitrous oxide, like ketamine, acts as an antagonist at glutamatergic N-methyld-aspartate (NMDA) receptors which are found throughout the brain. A brain-wide excitation of these receptors might be responsible for the laughing gas-induced increase in imagery vividness found in the study. Alternatively, the gas may have caused volunteers to partly withdraw from their reality of actively taking part in the tests, so that they felt less in control of their actions and felt that the suggested effects were happening by themselves.
“Many dentists use laughing gas to relieve discomfort in their patients, but our study suggests that combining the gas with instructions and suggestions to help them to relax and become absorbed in imagery, for example, might enhance the pain-relieving effect. Our findings are preliminary, however, so it would be helpful to do a larger scale study to confirm our results and explore the best ways in which to use and combine nitrous oxide and suggestion.
“Our study fixed the concentration of nitrous oxide at a relatively low 25 per cent, so it would be good to explore whether there is a dose-response relationship between drug administration and suggestibility. We already know that hypnosis enhances the effects of suggestion, so it would be helpful for clinicians to know whether combining laughing gas with hypnosis would increase suggestibility and enhance the analgesic (pain-killing) effects.
“A growing number of health professionals are trained in hypnosis but it is nothing to be alarmed about – people often think that hypnosis is about the hypnotist ‘taking control’ of the hypnotised person, but in reality the person undergoing hypnosis is an active participant and has to want to participate in order to experience a benefit. There is good evidence that although people can respond to suggestions under hypnosis, they can also choose to refuse any suggestion, and cannot be made to do things that they do not want to do.”
Emeritus Professor David Oakley, UCL Psychology, says: “It is estimated that between 250 and 500 dentists who have been trained in hypnosis in the UK are currently using hypnosis and suggestion to help their patients to deal with anxiety, discomfort and pain. This study provides further evidence that combining hypnotic suggestion with established procedures can be an effective way of making the experience of dentistry a more positive one for patients.”

FDA warning against droperidol unnecessary - Mayo Clinic study concludes

Fri, 28 Sep 2007 23:59:37 PST

( from http://www.rxpgnews.com ) A Mayo Clinic review of patients? responses to a drug used to control nausea and vomiting during anesthesia for general surgery questions a U.S. Food and Drug Administration (FDA) warning against the drug?s use. This study appears in the current issue of the journal Anesthesiology.

The FDA warning against droperidol was prompted in 2001 over concerns that the drug contributed to potentially fatal heart rhythm abnormalities. Mayo Clinic compared 139,932 patients? responses before the warning was issued (and droperidol was used) and found no proven cases of complications directly attributable to droperidol. In comparison, after the FDA warning, two of 151,256 patients had poor heart rhythm while receiving other, more expensive medication alternatives. The percentage of patients who received droperidol was 12 percent prior to the warning and 0 percent after placement of the warning.

Based on their findings, Mayo Clinic anesthesiologists conclude that the FDA warning against droperidol is unnecessary. They call for other investigators to study the topic to determine if further inquiry supports that conclusion.

?In our study, we obtained results that were just the opposite of what the FDA action would predict. We actually had fewer complications with droperidol,? explains Gregory Nuttall, M.D., the lead Mayo Clinic anesthesiologist on the study. ?In our experience, low-doses of droperidol used by a skilled team are the safer and more effective agent for controlling nausea and vomiting, which is why we are making plans to resume its low-dose use in select patients in the cardiac Intensive Care Unit.?

Study finds 'wake up and breathe' strategy allows patients to come off ventilator sooner

Tue, 22 May 2007 10:02:37 PST

( from http://www.rxpgnews.com ) A new study of intensive care unit patients who are breathing with the help of a mechanical ventilator has found that a two-step sedation and ventilator weaning protocol?called a ?wake up and breathe? strategy?helps patients come off the ventilator faster so that they can be discharged from the ICU and hospital more quickly. The study is being presented at the American Thoracic Society 2007 International Conference in San Francisco.

?On average, patients managed with the intervention spent four more days alive and out of the ICU and out of the hospital than those managed in the control group,? explained senior author Wes Ely, M.D., M.P.H., Professor of Medicine at Vanderbilt University and Associate Director of the Geriatric Research Education and Clinic Center.

In the first step of the protocol, the patient?s sedation is turned off, also known as a ?spontaneous awakening trial.? ?Almost all patients on a ventilator in the ICU receive sedating medications that keep them comfortable or even comatose,? says the study?s first author, Timothy Girard, M.D., M.S.C.I., also of the Vanderbilt University School of Medicine in Nashville. ?The spontaneous awakening trial (SAT) allows them to wake up, so we can find out if they are ready to proceed without sedation. If the patient is uncomfortable, we restart sedation, but a lot of patients are comfortable enough to proceed with the next step in the protocol.?

This second step involves allowing the patient to try breathing on their own without substantial help from the ventilator, called a ?spontaneous breathing trial.? If the patient shows signs they are unable to breathe on their own, they are immediately placed back on full mechanical ventilation.

The multicenter study included 335 critically ill patients in four hospitals who were receiving mechanical ventilation. Patients managed with the combined ?wake up and breathe? protocol (the SAT + SBT group) were compared with patients who were managed with daily spontaneous breathing trials and usual sedation practices (the SBT group). This group did not undergo formal awakening trials; their sedation was managed by their ICU doctors and nurses on a case-by-case basis.

The patients in the SAT+SBT group were able to breathe without the ventilator?s assistance an average of three days more and were discharged from the ICU and hospital an average of four days earlier than the SBT group. During the 28-day study, 47 patients in the SAT+SBT group died compared with 58 in the SBT group.

?Numbers on the monitor in the ICU aren?t very good at predicting if a patient is ready to come off a ventilator,? Dr. Girard says. ?In the past, the process of turning sedation drugs off has been done separately from turning off the ventilator. Our study proved our hypothesis that if we connect these two processes, it will safely allow patients to come off the ventilator earlier.?

Potential new pain killer drug developed by scientists at Leicester and Italy

Fri, 16 Mar 2007 05:14:56 PST

( from http://www.rxpgnews.com ) A potential new pain-killing drug developed by medical scientists at the University of Leicester and Ferrara in Italy is to be discussed at a public lecture on 20th March.

Professor David Lambert, who has been involved in the development the drug in collaboration with Dr Girolamo Calo in Ferrara Italy, believes the new drug called UFP-101 - avoids many of the side effects of morphine, currently the gold standard in pain reduction.

He said: "In a 2005 survey for the British Pain Society 975 people were questioned about pain. Twenty one percent experienced pain every day or most days equating to ~10million across the whole UK.

"Morphine produces its clinical effects by interaction with opioid receptors. In addition to acting as a pain killer this drug produces a number of unwanted side effects of importance from a clinical (e.g., depression of breathing, constipation and tolerance) and social (addiction) viewpoints.

"Clearly there is a place for new morphine like drugs without these side effects and the University of Leicester Anaesthesia Division has been at the forefront of such preclinical research."

Since appointment in 1991 as a lecturer Professor Lambert has been working on opioids and opioid receptors with particular emphasis on understanding receptor function and the design and evaluation of new drugs to target these receptors.

In collaboration with Dr Girolamo Calo his laboratory has characterised a prototype analgesic (pain killer), acting at a new opioid receptor, with a much reduced side effect profile.

In his inaugural lecture he will describe the current place of opioids in the clinic and development of UFP-101.

Near infrared laser device can measure brain oxygen levels

Tue, 25 Oct 2005 05:25:38 PST

( from http://www.rxpgnews.com ) A new device that uses near-infrared light to non-invasively monitor the oxygenation of the brain during surgery appears to be a promising alternative to the more invasive techniques currently in use, according to a new study by Duke University Medical Center anesthesiologists.

The researchers said their findings offer the potential for accurate and reliable monitoring of brain oxygenation during cardiac surgeries, to more effectively protect the brain against reduced oxygen levels, or anoxia, which is known to cause cognitive impairment in some surgical patients.

During some surgeries anesthesiologists measure venous oxygenation by periodically removing blood samples from catheters inserted in major blood vessels in the neck and then analyze the samples by co-oximetry. Also, anesthesiologists frequently use a pulse oximeter, attached to the patient's finger, to measure arterial blood oxygenation. However, since these measurements are taken on blood outside the brain, physicians can only estimate the level of cerebral oxygenation.

Designed by CAS Medical Systems, Inc., the monitor, called a cerebral oximeter, uses one or more sensors attached to the forehead that emit non-harmful, low-level laser light through the skin and skull into the brain. Since the near-infrared light absorption characteristics of the hemoglobin in red blood cells are known, the system can calculate the brain tissue oxygen saturation by measuring the differences in intensity of light as it passes through the brain. When combined with pulse oximetry, the cerebral oximeter may be used to estimate the cerebral venous oxygen saturation.

The basic principle of cerebral oximetry is based on optical spectroscopy techniques. The discovery that near-infrared light can pass through the scalp and skull to examine levels of hemoglobin and other light absorbing compounds of the brain was made at Duke by Frans Jobsis, Ph.D., in 1977.

"It has always been a challenge to directly measure the oxygen levels in the brain," said Duke anesthesiologist David MacLeod, M.D., who presented the results of the Duke study Oct. 22, 2005, at the annual scientific sessions of the American Society of Anesthesiologists in Atlanta. "The main issues with the invasive approach are that it does not provide specific information in real time, and it is of course invasive, which can carry some risk to the patient.

"This new technology, which is non-invasive and provides real-time information, appears to be an accurate means for measuring cerebral oxygenation and indirectly cerebral perfusion," MacLeod said. "As anesthesiologists, protecting the brain from potential harm is one of the main functions we perform during a surgical procedure."

For their study, the researchers enrolled 12 healthy volunteers. The volunteers were monitored using the different blood oxygenation measurement systems pulse oximetry, jugular and radial arterial co-oximetry, and the prototype cerebral oximeter. In a stepwise fashion, the researchers decreased and then increased the concentration of inhaled oxygen through a range of 70 to 100 percent arterial blood oxygen saturation. Frequent, concurrent measurements were made on all three systems throughout the process.

"We made a total of 171 readings and found a strong correlation between the reference co-oximetry measurements by the invasive methods to the non-invasive approaches," MacLeod said. "So it appears that we can use non-invasive approaches to estimate something we could in the past only measure with invasive sampling."

While pulse oximetry is used universally to measure arterial oxygen saturation for all patients undergoing surgery, interest in cerebral oxygenation levels have mainly been the domain of cardiac surgeons and anesthesiologists, according to MacLeod, given the rising concerns about potential cognitive impairments suffered by some patients undergoing open heart surgery.

Following this successful validation of the CAS cerebral oximeter, the Duke team is conducting a clinical trial to refine the optimal range of cerebral oxygenation in patients undergoing heart surgery. After surgery these patients will be periodically assessed to detect any correlation between cerebral oxygen levels during surgery and post-op changes in cognition.

Hospital characteristics play a role in use of do-not-resuscitate orders

Wed, 10 Aug 2005 13:12:38 PST

( from http://www.rxpgnews.com ) Hospital characteristics, including size, non-profit status and affiliation with a university, appear to be associated with use of do-not-resuscitate orders (DNR) in California, independent of the patient's characteristics, according to a study in the August 8/22 issue of the Archives of Internal Medicine, one of the JAMA/Archives journals.

Do-not-resuscitate orders are essential for guiding the care provided to hospitalized patients, according to background information in the article. Treatments like resuscitation may be inappropriate or may afford short-term benefits without achieving valued long-term goals. If DNR orders reflect patients' preferences and guide care that is consistent with these preferences, DNR orders can be considered indicators of the quality of health care at an institution, the authors suggest.

David S. Zingmond, M.D., Ph.D., and Neil S. Wenger, M.D., M.P.H., of The David Geffen School of Medicine at UCLA, Los Angeles, analyzed records from California hospitals to determine whether institutional factors were associated with the use of DNR orders. The researchers assessed the association between hospital characteristics, (size, profit status and academic status) and the use of a DNR order written within the first 24 hours of admission. The researchers also assessed whether there were regional differences in the use of DNR orders. Of approximately one and half million patients 50 or older admitted for acute care during 2000, the researchers included in their analysis 819,686 admissions at 386 California hospitals for 40 of the most common medical and surgical/procedural diagnoses-related groups (DRGs).

The researchers found that the percentage of DNR orders written within the first 24 hours of admission varied from two percent for patients aged 50-59 years to 17 percent for patients 80 years or older. The odds of having early DNR orders written were significantly lower in for-profit vs. private non-profit hospitals, were higher in the smallest vs. the largest hospitals, and were lower in academic vs. non-academic institutions. The rate of DNR order use varied by 10-fold depending on region with the highest rates in rural areas, the authors report.

"The initiation of end-of-life discussions and the implementation of DNR orders are important toward ensuring that patients receive care appropriate to their prognosis and preferences," the authors conclude. "Hospital characteristics appear to be associated with the use of DNR orders, even after accounting for differences in patient characteristics. This association reflects institutional culture, technological bent, and physician practice patterns."

Latest Data on Novel Short-acting Sedatives

Thu, 02 Jun 2005 10:30:38 PST

( from http://www.rxpgnews.com ) CeNeS Pharmaceuticals plc (AIM: CEN) (CeNeS or the Company) today announced that recent presentations at two anaesthesia congresses included new data on two of its product programmes: morphine-6-glucuronide (M6G) for postoperative pain and CeNeS short-acting sedative programme.

In a talk at the European Society for Intravenous Anaesthesia (EuroSIVA, Vienna, Austria 27th-28th May 2005 - www.eurosiva.org ) entitled New Drugs for Hypnosis and Sedation CeNeS Director of Drug Discovery, Dr Gavin Kilpatrick, gave the first public presentation of data on CeNeS novel short-acting sedatives.

The data supports the desired profile of a rapid onset and rapid offset of action and organ-independent metabolism. These compounds are being developed for use as sedatives for patients undergoing short diagnostic and surgical procedures. CeNeS lead short-acting sedative compound, CNS 7056X, is in pre-clinical development.

Immediately after the EuroSIVA meeting, the European Society for Anaesthesiology meeting (ESA, Vienna, Austria 28th-31st May 2005 - www.euroanesthesia.org ) included a symposium on morphine metabolites at which the distinguished academics, Professor Albert Dahan (Leiden, The Netherlands), Dr Magdi Hanna (London, UK) and Professor Lona Christrup (Copenhagen, Denmark) presented data on M6G.

The M6G presentations included new data from Professor Christrups unit at the Danish University of Pharmaceutical Services on the oral bioavailability of M6G and its potential use in the treatment of chronic pain. The conclusions presented by Professor Christrup were:

1. The constant and prolonged absorption of M6G after peroral administration might represent a physiological sustained release system, useful for the treatment of chronic pain.

2. Due to its hydrophilic properties and consequently the slow rate of entering into the CNS, M6G might have a low abuse potential compared to more lipophilic opioids.

3. The prolonged duration of analgesia, which is probably due to accumulation in brain extracellular fluid, makes M6G suited for treatment of chronic pain conditions.

4. M6G appears to give rise to lesser nausea/vomiting and respiratory depression than morphine.

5. Thus M6G might prove to be a therapeutic milestone in the treatment of chronic pain.

The symposium also discussed previously released data on the use of M6G as an analgesic for the treatment of post-operative pain and its reduced tendency to cause respiratory depression compared to morphine. Overall, the feedback from the attending anaesthetists was very positive regarding the potential clinical profile of M6G.

CeNeS is developing M6G as a new treatment for post-operative pain and continues to review M6Gs additional potential for the treatment of the chronic pain market. The compound is in Phase III clinical trials in postoperative pain.

Neil Clark, Chief Executive commented: These are two of the most prestigious annual events for anaesthetists in Europe. We are delighted to see that our programmes have achieved such a high profile and that M6G continues to gain support as a potentially significant new pain product.

About M6G

M6G (morphine-6-glucuronide) is a potent active metabolite of morphine. Morphine is one of the most effective opioid analgesics and is widely used for the management of moderate to severe pain, including the pain experienced by patients following a wide range of surgical operations. Over 130 million surgical procedures are carried out in the seven major pharmaceutical markets annually.

Morphine is acknowledged to be the gold standard treatment against which other parenteral analgesics are tested. Nonetheless, even after administration of morphine, various studies report that between 40-100% of patients continue to experience moderate to severe pain following surgery, indicating the clear need for new and effective treatments for postoperative pain. Morphine is also associated with a number of side effects including nausea, retching, vomiting and sedation. These side effects cause discomfort to the patient and add costs to their care by incurring the use of additional drugs to treat the side effects, as well as the costs of associated clinical and nursing care. Morphine is also associated with an increased risk of respiratory depression, a potentially fatal condition, at the higher doses required for management of severe pain.

Clinical studies have shown that M6G has an equivalent analgesic effect to morphine but also has an improved side effect profile, particularly a reduced tendency to cause nausea, vomiting, sedation and respiratory depression.

About CeNeS short-acting sedative programme

A series of short-acting sedatives were assigned to CeNeS from GlaxoSmithKline (GSK) in November 2003. Building on the experience gained with the short-acting opiate, remifentanil, these compounds were developed by GSK to improve upon the widely-used sedative, midazolam.

The lead compound, CNS 7056X, is an ester that is rapidly hydrolysed in the body by esterases to an inactive metabolite. An attractive potential advantage offered by this mechanism of deactivation is a more predictable onset and offset profile compared to that seen with midazolam. Pre-clinical studies reveal that CNS 7056X has a significantly shorter duration of action than midazolam. The lack of reliance on a cytochrome P450 system for metabolism also means less scope for drug-drug interactions than midazolam. CNS 7056X is currently in pre-clinical development.

Org 25969 - the First Selective Relaxant Binding Agent for Neuromuscular Block Reversal Enters Phase 3

Tue, 24 May 2005 10:05:38 PST

( from http://www.rxpgnews.com ) Organon and the US Food and Drug Administration (FDA) have reached agreement on the clinical development plan that will allow Org 25969 - the first selective relaxant binding agent to reverse neuromuscular block - to enter Phase 3 studies. The decision follows an End of Phase 2 meeting earlier this month, during which the FDA accepted the plans with only minor requests for additional data.

We are very pleased that the FDA has agreed with our plans for Phase 3 development. There is no doubt that Org 25969 - if successful in further development - will be one of the most significant advances in neuromuscular pharmacology in the last 20 years. Indications to date are positive commented Dr Willem de Laat, Executive Vice President, Development and Medical Affairs from Organon.

Reversal agents are administered after surgical procedures involving the use of muscle relaxants ( neuromuscular blocking agents or NMBAs ) to enable spontaneous breathing to recommence earlier. Current reversal agents can only be administered when muscle relaxation is starting to wear off naturally, delaying the possibility of reversing the blockage up to 30 minutes. They also have various side effects including cardiovascular effects.

Org 25969 - a selective relaxant binding agent ( SRBA ) - can achieve reversal following Esmeron® ( rocuronium bromide; one of the most widely used NMBAs ) administration within three minutes regardless of the depth of block and to date has shown less adverse effects than the currently available agents. ( Org 25969 is a modified cyclodextrin compound, which by itself does not have an appreciable activity in the body. )

The Phase 3 trials are expected to start in June and will involve approximately 1500 patients. They will assess reversal following administration of rocuronium and vecuronium. Results are expected in 2006 indicating that Org 25969 could be available as early as 2007.

Full data from three Phase 2 studies will be presented at the European Society of Anaesthesia Congress in Vienna, Austria later this month.

Dangerous reduction in Oxygen levels during Air Travel

Mon, 25 Apr 2005 19:35:38 PST

( from http://www.rxpgnews.com ) More than half of air travellers find that their oxygen saturation drops to a level at which many hospital patients would be prescribed extra oxygen, according to a paper in the May issue of Anaesthesia.

The study, by a team of Belfast researchers, found that oxygen levels fell by an average of four per cent when people reached cruising altitude.

84 passengers, aged from one to 78, had their oxygen saturation levels measured by qualified anaesthetists on the ground and at cruising altitude.

Ground levels averaged 97 per cent and these fell to an average of 93 per cent at altitude.

"We believe that these falling oxygen levels, together with factors such as dehydration, immobility and low humidity, could contribute to illness during and after flights" says Dr Susan Humphreys, Anaesthetic Specialist Registrar.

"This has become a greater problem in recent years as modern aeroplanes are able to cruise at much higher altitudes.

"The oxygen levels of 54 per cent of our subjects fell to less than 94 per cent at maximum altitude and an earlier study suggests that a third of physicians would put hospital patients with these levels on extra oxygen."

55 passengers were on long haul flights that lasted for more than two hours and the remaining 29 were on short haul flights. The measurements obtained from both groups were very similar. None of the subjects had severe cardio-respiratory problems and no-one required permission from their doctor to fly.

"The House of Lords and the Department of Transport have both acknowledged that more studies need to be carried out with respect to the effects of air travel on health, as there is little information on the physiological effects of flying on passengers currently available" adds Dr Rachel Deyermond, Consultant Anaesthetist.

"This is the first study to quantify the reduction of percentage oxygen saturation at high altitude during commercial air travel. It demonstrates that there is a significant fall in levels in all age groups during both short and long haul flights."