Bisacodyl: Are there differences in the quality of the pure substance and Dulcolax®?
Yes. It is known that the mode of action of a substance (e.g. Bisacodyl) can be modified and optimised by pharmaceutical technology. Even drugs with the same content of active ingredient, but processed differently when made into drugs (galenics), can show considerable differences in effect and impact. Dulcolax® is the original. The active ingredient Bisacodyl stems from research at Boehringer Ingelheim. Dulcolax® is designed in such a way that the active ingredient is transported unchanged through the stomach and small intestine (quod vide Intestine). It is protected by an active coating: the Comfort Coating. Neither the gastric acid nor the juices in the small intestine can damage the coating. Bisacodyl only takes effect in the large intestine, where the coating is dissolved.
Learn more about Bisacodyl and Dulcolax®
Further linksSodium Picosulphate Constipation Laxatives Stool softener Digestion Intestine Bowel movement Digestive disorder Digestion problem Stimulants Bisacodyl Constipation treatment
Tuesday, May 4, 2010
ATHLETIC PUBALGIA
ATHLETIC PUBALGIA
Athletic pubalgia, also called the sportman's hernia or sports hernia, Gilmore's groin or groin disruption, is a medical condition of the groin affecting athletes. Jerry Gilmore recognized the syndrome in 1980 and developed a surgical repair technique.
It is a syndrome characterized by chronic groin pain in athletes and a dilated superficial ring of the inguinal canal. Soccer and ice hockey players are affected most frequently, and both recreational and professional athletes may be affected. A hernia cannot be found on physical examination or medical imaging, and is not revealed during surgery. The term hernia thus is a misnomer, but has persisted, as surgical reconstructions similar to those performed for inguinal hernias are often effective for "sports hernias" as well.
PRESENTATION
Symptoms include pain during sports movements, particularly hip extension, and twisting and turning. This pain usually radiates to the adductor muscle region and even the testicles, although it is often difficult for the patient to pin-point the exact location.
Following sporting activity the person with athletic pubalgia will be stiff and sore. The day after a match, getting out of bed or a car will be difficult. Any exertion that increases intra-abdominal pressure, such as coughing, sneezing, or sporting activity can cause pain. In the early stages, the person may be able to continue playing their sport, but the problem usually gets progressively worse.
As pain in the groin and pelvis can be referred from a number of problems, including injuries to the lumbar spine, the hip joint, the sacro-iliac joint, the abdomen, and the genito-urinary system, diagnosis of athletic pubalgia requires skillful differentiation and pubic examination in certain cases where there is intense groin pain.
The diagnosis of Gilmore's groin is based on the patient's history and clinical signs. The most notable clinical sign is dilation of the superficial inguinal ring on the affected side, which can be palpated by the examining doctor when the scrotum is inverted with the little finger. Typically, there is specific pain on coughing and sneezing, as well as sitting up and squeezing the legs together.
The exact lesion may differ, but common pathologic findings at operation are:
1.torn external oblique aponeurosis
2.tear in the conjoint tendon
3.conjoint tendon torn from pubic tubercle
4.dehiscence between conjoined tendon and inguinal ligament
5.tear in the fascia transversalis
6.abnormal insertion of the rectus abdominis muscle
7.tear of the abdominal internal oblique muscle from the pubic tubercle
8.entrapment of the ilioinguinal nerve or genitofemoral nerve
Several of these lesions may occur simultaneously. Also, many athletes have concomitant weakness or tearing of the adductor muscles or labral tears of the hip. When the adductor muscles are tight post injury, that can be enough to trigger symptoms. The first conservative treatment option should be to restore normal motion after the adductor has begun to heal (usually 6-8 weeks post injury). Sleeping in a prone position with the hip on the affected side flexed and externally rotated can be a cure in some individuals.
The exact incidence of these entities is unknown: some believe it is the most common cause of chronic groin pain in athletes, while others argue that it is only rare. Conservative therapies (gentle stretching and a short period of rest) may temporarily alleviate the pain, but definitive treatment consists of surgical repair followed by a structured rehabilitation.
Athletic pubalgia, also called the sportman's hernia or sports hernia, Gilmore's groin or groin disruption, is a medical condition of the groin affecting athletes. Jerry Gilmore recognized the syndrome in 1980 and developed a surgical repair technique.
It is a syndrome characterized by chronic groin pain in athletes and a dilated superficial ring of the inguinal canal. Soccer and ice hockey players are affected most frequently, and both recreational and professional athletes may be affected. A hernia cannot be found on physical examination or medical imaging, and is not revealed during surgery. The term hernia thus is a misnomer, but has persisted, as surgical reconstructions similar to those performed for inguinal hernias are often effective for "sports hernias" as well.
PRESENTATION
Symptoms include pain during sports movements, particularly hip extension, and twisting and turning. This pain usually radiates to the adductor muscle region and even the testicles, although it is often difficult for the patient to pin-point the exact location.
Following sporting activity the person with athletic pubalgia will be stiff and sore. The day after a match, getting out of bed or a car will be difficult. Any exertion that increases intra-abdominal pressure, such as coughing, sneezing, or sporting activity can cause pain. In the early stages, the person may be able to continue playing their sport, but the problem usually gets progressively worse.
As pain in the groin and pelvis can be referred from a number of problems, including injuries to the lumbar spine, the hip joint, the sacro-iliac joint, the abdomen, and the genito-urinary system, diagnosis of athletic pubalgia requires skillful differentiation and pubic examination in certain cases where there is intense groin pain.
The diagnosis of Gilmore's groin is based on the patient's history and clinical signs. The most notable clinical sign is dilation of the superficial inguinal ring on the affected side, which can be palpated by the examining doctor when the scrotum is inverted with the little finger. Typically, there is specific pain on coughing and sneezing, as well as sitting up and squeezing the legs together.
The exact lesion may differ, but common pathologic findings at operation are:
1.torn external oblique aponeurosis
2.tear in the conjoint tendon
3.conjoint tendon torn from pubic tubercle
4.dehiscence between conjoined tendon and inguinal ligament
5.tear in the fascia transversalis
6.abnormal insertion of the rectus abdominis muscle
7.tear of the abdominal internal oblique muscle from the pubic tubercle
8.entrapment of the ilioinguinal nerve or genitofemoral nerve
Several of these lesions may occur simultaneously. Also, many athletes have concomitant weakness or tearing of the adductor muscles or labral tears of the hip. When the adductor muscles are tight post injury, that can be enough to trigger symptoms. The first conservative treatment option should be to restore normal motion after the adductor has begun to heal (usually 6-8 weeks post injury). Sleeping in a prone position with the hip on the affected side flexed and externally rotated can be a cure in some individuals.
The exact incidence of these entities is unknown: some believe it is the most common cause of chronic groin pain in athletes, while others argue that it is only rare. Conservative therapies (gentle stretching and a short period of rest) may temporarily alleviate the pain, but definitive treatment consists of surgical repair followed by a structured rehabilitation.
STUDY OF IMPLANT MESH
Characterization of heavyweight and lightweight polypropylene prosthetic mesh explants from a single patient
Although polypropylene has been used as a hernia repair material for nearly 50 years, very little science has been applied to studying the body's effect on this material. It is possible that oxidation of mesh occurs as a result of the chemical structure of polypropylene and the physiological conditions to which it is subjected; this leads to embrittlement of the material, impaired abdominal movement, and chronic pain. It is also possible that lightweight polypropylene meshes undergo less oxidation due to a reduced inflammatory reaction. The objective of this study was to characterize explanted hernia meshes using techniques such as scanning electron microscopy, differential scanning calorimetry, thermogravimetric analysis, and compliance testing to determine whether the mesh density of polypropylene affects the oxidative degradation of the material. The hypothesis was that heavyweight polypropylene would incite a more intense inflammatory response than lightweight polypropylene and thus undergo greater oxidative degradation. Overall, the results support this theory.
Although polypropylene has been used as a hernia repair material for nearly 50 years, very little science has been applied to studying the body's effect on this material. It is possible that oxidation of mesh occurs as a result of the chemical structure of polypropylene and the physiological conditions to which it is subjected; this leads to embrittlement of the material, impaired abdominal movement, and chronic pain. It is also possible that lightweight polypropylene meshes undergo less oxidation due to a reduced inflammatory reaction. The objective of this study was to characterize explanted hernia meshes using techniques such as scanning electron microscopy, differential scanning calorimetry, thermogravimetric analysis, and compliance testing to determine whether the mesh density of polypropylene affects the oxidative degradation of the material. The hypothesis was that heavyweight polypropylene would incite a more intense inflammatory response than lightweight polypropylene and thus undergo greater oxidative degradation. Overall, the results support this theory.
Sunday, May 2, 2010
MHD GENERATOR
The MHD (magnetohydrodynamic) generator or dynamo transforms thermal energy or kinetic energy directly into electricity. MHD generators are different from traditional electric generators in that they can operate at high temperatures without moving parts. MHD was developed because the exhaust of a plasma MHD generator is a flame, still able to heat the boilers of a steam power plant. So high-temperature MHD was developed as a topping cycle to increase the efficiency of electric generation, especially when burning coal or natural gas. It has also been applied to pump liquid metals and for quiet submarine engines.
The basic concept underlying the mechanical and fluid dynamos is the same. The fluid dynamo, however, uses the motion of fluid or plasma to generate the currents which generate the electrical energy. The mechanical dynamo, in contrast, uses the motion of mechanical devices to accomplish this. The functional difference between an MHD generator and an MHD dynamo is the path the charged particles follow.
MHD generators are now practical for fossil fuels, but have been overtaken by other, less expensive technologies, such as combined cycles in which a gas turbine's or molten carbonate fuel cell's exhaust heats steam for steam turbine. The unique value of MHD is that it permits an older single-cycle fossil-fuel power plant to be upgraded to high efficiency.
Natural MHD dynamos are an active area of research in plasma physics and are of great interest to the geophysics and astrophysics communities. From their perspective the earth is a global MHD dynamo and with the aid of the particles on the solar wind produces the aurora borealis. The differently charged electromagnetic layers produced by the dynamo effect on the earth's geomagnetic field enable the appearance of the aurora borealis. As power is extracted from the plasma of the solar wind, the particles slow and are drawn down along the field lines in a brilliant display over the poles.
The Lorentz Force Law describes the effects of a charged particle moving in a constant magnetic field. The simplest form of this law is given by the vector equation.
F= q.(vxB)
where
F is the force acting on the particle,
Q is charge of particle,
v is velocity of particle,
B is magnetic field.
The vector F is perpendicular to both v and B according to the Right hand rule.
Typically for a large scale power station to approach operational efficiency in computer models, steps must be taken to increase the electrical conductivity of the conductive substance. The heating of a gas to plasma or the addition of other easily ionizable substances like the salts of alkali metals accomplishes this increase in conductivity. In practice a number of issues must be considered in the implementation of a MHD generator: Generator efficiency, Economics, and Toxic byproducts. These issues are affected by the choice of one of the three MHD generator designs. These are the Faraday generator, the Hall generator, and the disc.
Faraday generator
The Faraday generator is named after the man who first looked for the effect in the Thames river (see history). A simple Faraday generator would consist of a wedge-shaped pipe or tube of some non-conductive material. When an electrically conductive fluid flows through the tube, in the presence of a significant perpendicular magnetic field, a charge is induced in the field, which can be drawn off as electrical power by placing the electrodes on the sides at 90 degree angles to the magnetic field.
There are limitations on the density and type of field used. The amount of power that can be extracted is proportional to the cross sectional area of the tube and the speed of the conductive flow. The conductive substance is also cooled and slowed by this process. MHD generators typically reduce the temperature of the conductive substance from plasma temperatures to just over 1000 °C.
The main practical problem of a Faraday generator is that differential voltages and currents in the fluid short through the electrodes on the sides of the duct. The most powerful waste is from the Hall effect current. This makes the Faraday duct very inefficient. Most further refinements of MHD generators have tried to solve this problem. The optimal magnetic field on duct-shaped MHD generators is a sort of saddle shape. To get this field, a large generator requires an extremely powerful magnet. Many research groups have tried to adapt superconducting magnets to this purpose, with varying success.
Hall generator
The most common answer is to use the Hall effect to create a current that flows with the fluid. The normal scheme is to place arrays of short, vertical electrodes on the sides of the duct. The first and last electrodes in the duct power the load. Each other electrode is shorted to an electrode on the opposite side of the duct. These shorts of the Faraday current induce a powerful magnetic field within the fluid, but in a chord of a circle at right angles to the Faraday current. This secondary, induced field makes current flow in a rainbow shape between the first and last electrodes.
Losses are less than a Faraday generator, and voltages are higher because there is less shorting of the final induced current. However, this design has problems because the speed of the material flow requires the middle electrodes to be offset to "catch" the Faraday currents. As the load varies, the fluid flow speed varies, misaligning the Faraday current with its intended electrodes, and making the generator's efficiency very sensitive to its load.
Disc generator
The third, currently most efficient answer is the Hall effect disc generator. This design currently holds the efficiency and energy density records for MHD generation. A disc generator has fluid flowing between the center of a disc, and a duct wrapped around the edge. The magnetic excitation field is made by a pair of circular Helmholtz coils above and below the disk. The Faraday currents flow in a perfect dead short around the periphery of the disk. The Hall effect currents flow between ring electrodes near the center and ring electrodes near the periphery.
Another significant advantage of this design is that the magnet is more efficient. First, it has simple parallel field lines. Second, because the fluid is processed in a disk, the magnet can be closer to the fluid, and magnetic field strengths increase as the 7th power of distance. Finally, the generator is compact for its power, so the magnet is also smaller. The resulting magnet uses a much smaller percentage of the generated power.
The basic concept underlying the mechanical and fluid dynamos is the same. The fluid dynamo, however, uses the motion of fluid or plasma to generate the currents which generate the electrical energy. The mechanical dynamo, in contrast, uses the motion of mechanical devices to accomplish this. The functional difference between an MHD generator and an MHD dynamo is the path the charged particles follow.
MHD generators are now practical for fossil fuels, but have been overtaken by other, less expensive technologies, such as combined cycles in which a gas turbine's or molten carbonate fuel cell's exhaust heats steam for steam turbine. The unique value of MHD is that it permits an older single-cycle fossil-fuel power plant to be upgraded to high efficiency.
Natural MHD dynamos are an active area of research in plasma physics and are of great interest to the geophysics and astrophysics communities. From their perspective the earth is a global MHD dynamo and with the aid of the particles on the solar wind produces the aurora borealis. The differently charged electromagnetic layers produced by the dynamo effect on the earth's geomagnetic field enable the appearance of the aurora borealis. As power is extracted from the plasma of the solar wind, the particles slow and are drawn down along the field lines in a brilliant display over the poles.
The Lorentz Force Law describes the effects of a charged particle moving in a constant magnetic field. The simplest form of this law is given by the vector equation.
F= q.(vxB)
where
F is the force acting on the particle,
Q is charge of particle,
v is velocity of particle,
B is magnetic field.
The vector F is perpendicular to both v and B according to the Right hand rule.
Typically for a large scale power station to approach operational efficiency in computer models, steps must be taken to increase the electrical conductivity of the conductive substance. The heating of a gas to plasma or the addition of other easily ionizable substances like the salts of alkali metals accomplishes this increase in conductivity. In practice a number of issues must be considered in the implementation of a MHD generator: Generator efficiency, Economics, and Toxic byproducts. These issues are affected by the choice of one of the three MHD generator designs. These are the Faraday generator, the Hall generator, and the disc.
Faraday generator
The Faraday generator is named after the man who first looked for the effect in the Thames river (see history). A simple Faraday generator would consist of a wedge-shaped pipe or tube of some non-conductive material. When an electrically conductive fluid flows through the tube, in the presence of a significant perpendicular magnetic field, a charge is induced in the field, which can be drawn off as electrical power by placing the electrodes on the sides at 90 degree angles to the magnetic field.
There are limitations on the density and type of field used. The amount of power that can be extracted is proportional to the cross sectional area of the tube and the speed of the conductive flow. The conductive substance is also cooled and slowed by this process. MHD generators typically reduce the temperature of the conductive substance from plasma temperatures to just over 1000 °C.
The main practical problem of a Faraday generator is that differential voltages and currents in the fluid short through the electrodes on the sides of the duct. The most powerful waste is from the Hall effect current. This makes the Faraday duct very inefficient. Most further refinements of MHD generators have tried to solve this problem. The optimal magnetic field on duct-shaped MHD generators is a sort of saddle shape. To get this field, a large generator requires an extremely powerful magnet. Many research groups have tried to adapt superconducting magnets to this purpose, with varying success.
Hall generator
The most common answer is to use the Hall effect to create a current that flows with the fluid. The normal scheme is to place arrays of short, vertical electrodes on the sides of the duct. The first and last electrodes in the duct power the load. Each other electrode is shorted to an electrode on the opposite side of the duct. These shorts of the Faraday current induce a powerful magnetic field within the fluid, but in a chord of a circle at right angles to the Faraday current. This secondary, induced field makes current flow in a rainbow shape between the first and last electrodes.
Losses are less than a Faraday generator, and voltages are higher because there is less shorting of the final induced current. However, this design has problems because the speed of the material flow requires the middle electrodes to be offset to "catch" the Faraday currents. As the load varies, the fluid flow speed varies, misaligning the Faraday current with its intended electrodes, and making the generator's efficiency very sensitive to its load.
Disc generator
The third, currently most efficient answer is the Hall effect disc generator. This design currently holds the efficiency and energy density records for MHD generation. A disc generator has fluid flowing between the center of a disc, and a duct wrapped around the edge. The magnetic excitation field is made by a pair of circular Helmholtz coils above and below the disk. The Faraday currents flow in a perfect dead short around the periphery of the disk. The Hall effect currents flow between ring electrodes near the center and ring electrodes near the periphery.
Another significant advantage of this design is that the magnet is more efficient. First, it has simple parallel field lines. Second, because the fluid is processed in a disk, the magnet can be closer to the fluid, and magnetic field strengths increase as the 7th power of distance. Finally, the generator is compact for its power, so the magnet is also smaller. The resulting magnet uses a much smaller percentage of the generated power.
UFO MEETING IN TOULOUSE
In English
It was an dinner focused on science and UFO in Toulouse (France). Fifty people had gathered for the occasion. The guest was Mathieu Ader, a member of the Association UFO-Science , and co-leader of the group OvniTech.
The presentation began with a statement of what has been done in ufology past three decades. First, a point of view of official institutions in charge of the case. There are lot of records of police available on the website GEIPAN representing the log of thousands of witnesses. But none of these log contain real scientific data.
The few documents that catch our attention are technical notes, following the investigations of some famous cases of modern ufology.
Then the point of view of the scientific community in general, where the UFO phenomenon is still a taboo. The main risk is the collapse of a large number of well-established dogma, a questioning of our current knowledge.
A few high-level work have been present: those of Professor Michael Bounias (chromatography) in the case of Trans-en-Provence in 1981, and those of Jean-Pierre Petit (Director of Research at CNRS) in laboratory experiments conducted in the 70s on Magnetohydrodynamics (MHD).
In Francais
Ce fut une soirée axée sur la science au Repas Ufologique toulousain. Une cinquantaine de personnes s’est réunie pour l’occasion. L’invité était Mathieu Ader, membre de l’association UFO-Science, et coresponsable du groupe OvniTech.
La présentation a commencée par un constat de ce qui a été fait en ufologie ces trois dernières décennies. D’abord, d’un point de vue des institutions officielles en charge du dossier. On dénombre une grande quantité de procès-verbaux de gendarmerie disponibles sur le site du GEIPAN, représentant l’audition de plusieurs milliers de témoins. Seulement, aucun de ces PV n’apportent de réelles données scientifiques.
Les quelques rares documents qui retiennent notre attention sont plutôt des notes techniques, faisant suite aux enquêtes de certains cas célèbres de l’ufologie moderne.
Vient ensuite le point de vue de la communauté scientifique en général, où le phénomène Ovni relève encore d’un tabou. Le risque majeur étant l’effondrement d’un grand nombre de dogme bien établis ; une remise en cause de nos connaissances actuelles.Quelques rares travaux de haut niveau ont été mis en avant : ceux du professeur Michel Bounias en chromatographie sur le cas de Trans-en-Provence en 1981, ainsi que ceux de Jean-Pierre Petit (directeur de recherche au CNRS) en ce qui concerne les expériences en laboratoire réalisées dans les années 70 sur la Magnétohydrodynamique (MHD).
Partant de ce constat, et du fait que l’étude du sujet Ovni implique une collaboration entre scientifiques de plusieurs disciplines, UFO-Science vit le jour début 2007. Cette structure indépendante, présidée par Jean-Pierre Petit, a pour but d’instruire le dossier en mettant en place des méthodes rationnelles et scientifiques.
It was an dinner focused on science and UFO in Toulouse (France). Fifty people had gathered for the occasion. The guest was Mathieu Ader, a member of the Association UFO-Science , and co-leader of the group OvniTech.
The presentation began with a statement of what has been done in ufology past three decades. First, a point of view of official institutions in charge of the case. There are lot of records of police available on the website GEIPAN representing the log of thousands of witnesses. But none of these log contain real scientific data.
The few documents that catch our attention are technical notes, following the investigations of some famous cases of modern ufology.
Then the point of view of the scientific community in general, where the UFO phenomenon is still a taboo. The main risk is the collapse of a large number of well-established dogma, a questioning of our current knowledge.
A few high-level work have been present: those of Professor Michael Bounias (chromatography) in the case of Trans-en-Provence in 1981, and those of Jean-Pierre Petit (Director of Research at CNRS) in laboratory experiments conducted in the 70s on Magnetohydrodynamics (MHD).
In Francais
Ce fut une soirée axée sur la science au Repas Ufologique toulousain. Une cinquantaine de personnes s’est réunie pour l’occasion. L’invité était Mathieu Ader, membre de l’association UFO-Science, et coresponsable du groupe OvniTech.
La présentation a commencée par un constat de ce qui a été fait en ufologie ces trois dernières décennies. D’abord, d’un point de vue des institutions officielles en charge du dossier. On dénombre une grande quantité de procès-verbaux de gendarmerie disponibles sur le site du GEIPAN, représentant l’audition de plusieurs milliers de témoins. Seulement, aucun de ces PV n’apportent de réelles données scientifiques.
Les quelques rares documents qui retiennent notre attention sont plutôt des notes techniques, faisant suite aux enquêtes de certains cas célèbres de l’ufologie moderne.
Vient ensuite le point de vue de la communauté scientifique en général, où le phénomène Ovni relève encore d’un tabou. Le risque majeur étant l’effondrement d’un grand nombre de dogme bien établis ; une remise en cause de nos connaissances actuelles.Quelques rares travaux de haut niveau ont été mis en avant : ceux du professeur Michel Bounias en chromatographie sur le cas de Trans-en-Provence en 1981, ainsi que ceux de Jean-Pierre Petit (directeur de recherche au CNRS) en ce qui concerne les expériences en laboratoire réalisées dans les années 70 sur la Magnétohydrodynamique (MHD).
Partant de ce constat, et du fait que l’étude du sujet Ovni implique une collaboration entre scientifiques de plusieurs disciplines, UFO-Science vit le jour début 2007. Cette structure indépendante, présidée par Jean-Pierre Petit, a pour but d’instruire le dossier en mettant en place des méthodes rationnelles et scientifiques.
HEISENBERG'S UNCERTAINTY PRINCIPLE
Heisenberg's uncertainty principle states that the speed (or momentum) and position of a particle at an instant cannot both be known exactly - the more precisely you measure one, the less you can find out about the other. Werner Heisenberg argued that the very act of observing a particle changes it, making precise knowledge impossible. So neither the past nor the future behaviour of any subatomic particle can be predicted with certainty. Determinism is dead.
In 1927, Heisenberg realized that quantum theory contained some strange predictons. It implied that experiments could never be done in complete isolation because the very act of measurement affected the outcome. He expressed this connection in his 'uncertainty principle'-you cannot simultaneously measure both the position and momentum of a subatomic particle (or equivalently its energy at an accurate time). If you know one then the other is always uncertain. You can measure both within certain bounds, but the more tightly these bounds are specified for one, the looser they become for the other. This uncertainty, he argued, was a deep consequence of quantum mechanics - it had nothing to do with a lack of skill or accuracy in measuring.
In 1927, Heisenberg realized that quantum theory contained some strange predictons. It implied that experiments could never be done in complete isolation because the very act of measurement affected the outcome. He expressed this connection in his 'uncertainty principle'-you cannot simultaneously measure both the position and momentum of a subatomic particle (or equivalently its energy at an accurate time). If you know one then the other is always uncertain. You can measure both within certain bounds, but the more tightly these bounds are specified for one, the looser they become for the other. This uncertainty, he argued, was a deep consequence of quantum mechanics - it had nothing to do with a lack of skill or accuracy in measuring.
BISPECTRAL INDEX MONITORING
Bispectral index monitoring to prevent awareness during anaesthesia: the B-Aware randomised controlled trial byMyles PS, Leslie K, McNeil J, Forbes A, Chan MT.Department of Anaesthesia and Pain Management,Alfred Hospital, Melbourne, Australia. p.myles@alfred.org.au. Lancet. 2004 May 29;363(9423):1757-63.
ABSTRACT
BACKGROUND: Awareness is an uncommon complication of anaesthesia, affecting 0.1-0.2% of all surgical patients. Bispectral index (BIS) monitoring measures the depth of anaesthesia and facilitates anaesthetic titration. In this trial we determined whether BIS-guided anaesthesia reduced the incidence of awareness during surgery in adults. METHODS: We did a prospective, randomised, double-blind, multicentre trial. Adult patients at high risk of awareness were randomly allocated to BIS-guided anaesthesia or routine care. Patients were assessed by a blinded observer for awareness at 2-6 h, 24-36 h, and 30 days after surgery. An independent committee, blinded to group identity, assessed every report of awareness. The primary outcome measure was confirmed awareness under anaesthesia at any time. FINDINGS: Of 2463 eligible and consenting patients, 1225 were assigned to the BIS group and 1238 to the routine care group. There were two reports of awareness in the BIS-guided group and 11 reports in the routine care group (p=0.022). BIS-guided anaesthesia reduced the risk of awareness by 82% (95% CI 17-98%). INTERPRETATION: BIS-guided anaesthesia reduces the risk of awareness in at-risk adult surgical patients undergoing relaxant general anaesthesia. With a cost of routine BIS monitoring at US16 dollars per use in Australia and a number needed to treat of 138, the cost of preventing one case of awareness in high-risk patients is about 2200 dollars.
Molecular mechanisms of anesthesia byUeda I. Anesthesia Service and Research,VA Salt Lake City Health Care System,University of Utah School of Medicine,Salt Lake City, UT, USA. issaku.ueda@m.cc.utah.edu Keio J Med. 2001 Mar;50(1):20-5
ABSTRACT
Anesthesia was a blessing to humankind. It is a miracle that simple molecules such as chloroform (CHCl3), diethyl ether (CH3.CH2.O.CH2.CH3), or nitrous oxide (N2O) induce a state of unconsciousness where patients can tolerate surgery. The diversity of the structures of these molecules indicates that there are no common receptors. The action of anesthetics is nonspecific and physical. After the demonstration by Meyer and Overton that anesthetic potencies correlate to their solubility into olive oil, the nonspecific lipid theories monopolized anesthesia theories for almost a century. The dominance of lipid theories invited repulsions against the nonspecificity idea. Protein theories that stress receptor bindings became the top mode. Nevertheless, the wide varieties of anesthetic molecules and the wide varieties of responding systems are difficult to reconcile with the specific interaction concept. This article discusses the recent progress and controversies on the molecular mechanisms of anesthesia. Anesthetics are unique drugs in pharmacology. They affect all macromolecules. The only comparable drugs are disinfectants. Both are nonspecific drugs. We use alcohols and phenols to wipe off the injection sites. We do not use penicillin or any other antibiotics for this purpose, because they are specific binders. Interestingly, these two nonspecific drugs opened the window for the modern medicine.
ABSTRACT
BACKGROUND: Awareness is an uncommon complication of anaesthesia, affecting 0.1-0.2% of all surgical patients. Bispectral index (BIS) monitoring measures the depth of anaesthesia and facilitates anaesthetic titration. In this trial we determined whether BIS-guided anaesthesia reduced the incidence of awareness during surgery in adults. METHODS: We did a prospective, randomised, double-blind, multicentre trial. Adult patients at high risk of awareness were randomly allocated to BIS-guided anaesthesia or routine care. Patients were assessed by a blinded observer for awareness at 2-6 h, 24-36 h, and 30 days after surgery. An independent committee, blinded to group identity, assessed every report of awareness. The primary outcome measure was confirmed awareness under anaesthesia at any time. FINDINGS: Of 2463 eligible and consenting patients, 1225 were assigned to the BIS group and 1238 to the routine care group. There were two reports of awareness in the BIS-guided group and 11 reports in the routine care group (p=0.022). BIS-guided anaesthesia reduced the risk of awareness by 82% (95% CI 17-98%). INTERPRETATION: BIS-guided anaesthesia reduces the risk of awareness in at-risk adult surgical patients undergoing relaxant general anaesthesia. With a cost of routine BIS monitoring at US16 dollars per use in Australia and a number needed to treat of 138, the cost of preventing one case of awareness in high-risk patients is about 2200 dollars.
Molecular mechanisms of anesthesia byUeda I. Anesthesia Service and Research,VA Salt Lake City Health Care System,University of Utah School of Medicine,Salt Lake City, UT, USA. issaku.ueda@m.cc.utah.edu Keio J Med. 2001 Mar;50(1):20-5
ABSTRACT
Anesthesia was a blessing to humankind. It is a miracle that simple molecules such as chloroform (CHCl3), diethyl ether (CH3.CH2.O.CH2.CH3), or nitrous oxide (N2O) induce a state of unconsciousness where patients can tolerate surgery. The diversity of the structures of these molecules indicates that there are no common receptors. The action of anesthetics is nonspecific and physical. After the demonstration by Meyer and Overton that anesthetic potencies correlate to their solubility into olive oil, the nonspecific lipid theories monopolized anesthesia theories for almost a century. The dominance of lipid theories invited repulsions against the nonspecificity idea. Protein theories that stress receptor bindings became the top mode. Nevertheless, the wide varieties of anesthetic molecules and the wide varieties of responding systems are difficult to reconcile with the specific interaction concept. This article discusses the recent progress and controversies on the molecular mechanisms of anesthesia. Anesthetics are unique drugs in pharmacology. They affect all macromolecules. The only comparable drugs are disinfectants. Both are nonspecific drugs. We use alcohols and phenols to wipe off the injection sites. We do not use penicillin or any other antibiotics for this purpose, because they are specific binders. Interestingly, these two nonspecific drugs opened the window for the modern medicine.
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