scubadoc Ten Foot Stop

October 31, 2008

Dehydration and Diving

Filed under: Articlescubadoc @ 12:13 pm

Dehydration and Diving



Dehydration Defined

Dehydration means your body does not have as much water and fluids as it should. Dehydration can be caused by losing too much fluid, not drinking enough water or fluids, or both. Vomiting and diarrhea are common causes. Pressurized airplane cabins, scuba air, alcoholic and other diuretic drinks, diuretic medications and certain medical conditions such as diabetes can cause dehydration.

Children divers are more susceptible to dehydration than adults because of their smaller body weights and higher turnover of water and electrolytes. The elderly and those with illnesses are also at higher risk.

Dehydration is classified as mild, moderate, or severe based on how much of the body’s fluid is lost or not replenished. When severe, dehydration is a life-threatening emergency. It is a known hazard to divers by increasing the risk for decompression illness.

Some of the smptoms of dehydration include:

* Dry or sticky mouth
* Low or no urine output; concentrated urine appears dark yellow
* Not producing tears
* Sunken eyes
* Lethargic or comatose (with severe dehydration)

Signs and tests indicating dehydration include:

A physical examination may also show signs of:

* Low blood pressure
* Blood pressure that drops when you go from lying down to standing
* Rapid heart rate
* Poor skin turgor — the skin may lack its normal elasticity and sag back into position slowly when pinched up into a fold by the doctor; normally, skin springs right back into position
* Delayed capillary refill
* Shock

Tests include:

* Blood chemistries (to check electrolytes, especially sodium, potassium, and bicarbonate levels)
* Urine specific gravity (a high specific gravity indicates significant dehydration)
* BUN (blood urea nitrogen — may be elevated with dehydration)
* Creatinine (may be elevated with dehydration)
* Complete Blood Count (CBC) to look for signs of concentrated blood

Other tests may be done to determine the specific cause of the dehydration (for example, a blood sugar to check for diabetes).


Diuretics Diuretics add to the dehydration that occurs with exercise from  sweating, insensible and respiratory water loss; the diver also has to take into consideration some additional concerns for fluid loss and replacement.

 1. Scuba tanks have extremely dry air inside. As this air is taken into the lungs and saturated–nearly twice the normal amount of water is lost from the body.

 2. Negative pressure breathing causes divers to lose about 350 cc/hour from their circulating blood volume, a phenomenon called immersion diuresis and seen also in snorkelers and swimmers.

3. Cold inhibits anti diuretic hormone, causes peripheral vasoconstriction, driving fluid back into the core and stimulating diuresis resulting in losses of plasma volume.

4. The hypercarbia (high blood carbon dioxide) associated with diving decreases anti diuretic hormone, promoting fluid loss from the plasma volume.

5. Diuretics such as alcohol, coffee, tea also contribute to fluid losses, contributing to predive dehydration.

6. Khosla in 1979 found that there is a 4% hemodilution in early immersion from ECF (extracellular fluid) shift into the bloodstream, resulting in an increase in central blood volume. This alters stimulation of pressure and volume receptors, leading to further inhibition of ADH (anti-diuretic hormone) and fluid loss.

7. In addition to the above, the state of chronic hypovolemia (low fluid vloume) and hypokalemia (low serum potassium) caused by oral diuretics is dangerous to divers by increasing their susceptibility to decompression illness and cardiac arrhythmias, respectively.

     A good start in reading about this problem would be in “Diving Medicine”, Bove and Davis, Philadelphia, WB Saunders, 1990, ed 2.

Also try Edmonds C., Lowry C, Pennefather J.:Diving and Subaquatic Medicine.
Oxford, Butterworth-Heinemann, 1992,ed 3., and  Bennett and Elliott (Eds): The Physiology and Medicine of Diving. London, WB Saunders, 1993, ed 4.

   The importance of entering a dive well-hydrated cannot be over-stated. Prehydration of divers should include regular ingestion of fluids several hours before, 15-20 minutes before and between dives, particularly if multiple dives are to be made each day. The urine should be “clear and copious”, the urine test for divers proposed by Dr. Jeff Davis.

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October 29, 2008

Hyperventilation and Diving

Filed under: Articlescubadoc @ 4:25 pm

Compiled by Ernest S Campbell, MD


What is Hyperventilation

Hyperventilation is the breathing response kicked off by chemical changes in the blood such as high CO2 or low oxygen level. It can also be set off by an acute panic attack or anxiety attack. It occurs mainly in out of shape, inexperienced divers or in divers with malfunctioning regulators. It can be managed simply by assisting the diver to the surface in a controlled fashion from behind, holding the regulator in the divers mouth. Since the diver is breathing, there’s little need to worry about pulmonary over pressure accidents from breath-holding. The diver blows off excessive quantities of CO2 thus lowering the serum calcium level, which can result in ‘tetany’ - a condition in which the muscles go into involuntary spasm. On the surface, the condition is managed quite well by rebreathing into a paper bag - thus elevating the CO2 level, the calcium level with a resultant return to normal of the neuromuscular activity.



What Causes Hyperventilation?Hyperventilation is an unreasoning rapid breathing associated with psychological shortness of breath or feeling of smothering and is one of the symptom complex of a panic attack. It feeds on itself by producing a marked lowering of the pCO2 (carbon dioxide levels) with an associated drop of blood calcium levels resulting in tetany (spastic loss of muscle function). This results in a vicious cycle — pushing the diver into a peripheral narrowing and locked into panic driven behavior. Rapid breathing can also be caused by faulty equipment, causing a retention of CO2.



Peripheral NarrowingDr. Glen Egstrom, in “Stress and Scuba Diving”, states that peripheral narrowing causes such panic driven behavior by the diver with ineffective problem- solving, even in the highly trained individual.



What to Do?The physical effects of hyperventilation can be solved nicely on the surface by rebreathing CO2 in a paper bag or other distensible sack. This is impossible at depth and hyperventilation becomes an emergency requiring a controlled assisted ascent, with the strong possibility that rescue will be needed on the surface, due to the ineffectual, inappropriate behavior caused by the focused peripheral narrowing of the panic attack.



Should the Diver Continue to Dive?The diver should have an independent skilled technician check out his scuba gear, paying close attention to his regulator. If this is not a problem, the diver should ask himself:

  • Am I prepared to dive anymore? Scuba is fun, not a contest.
  • Are there any physical reasons which might have caused my over breathing? Did I have a cold, gastroenteritis, fatigue, hangover or was I terribly out of shape for the type of diving that I was doing?
  • Am I a “Dragooned” diver as Dr. Jeff Davis called the diver that was diving to please a friend or spouse? Is my training adequate for this type of diving or has it been a long time between diving trips?
  • Is the environment difficult, with high current, rough seas, cold water or bad weather?

All of these things can cause anxiety to start and, as has been noted, it can feed on itself and rapidly grow unmanageable. One should freely admit to pre-dive insecurity and get the dive guides to stay near you in order to assist if needed.

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October 28, 2008

Immersion Pulmonary Edema

Filed under: Uncategorizedscubadoc @ 1:17 pm

We have a request from Duke University Medical Student Dionne Peacher for information regarding divers with a history of pulmonary edema of diving.
Dear Dr. Campbell,

I work with Dr. Richard Moon at the Duke Center for Hyperbaric Medicine and Environmental Physiology in Durham, North Carolina. We are currently recruiting subjects for a study about immersion pulmonary edema (pulmonary edema of diving). In particular, we’re looking for folks who have had immersion pulmonary edema. Since it is a relatively rare (or rarely recognized) event, we’re recruiting from all over the country.

I was wondering if you would know of any divers who have had immersion pulmonary edema to whom you could pass along our info.

Also, I wondered if you would be willing to post our blurb or ad on your scubadoc.com website or your blog.

If this sounds like something you might be able to help us with, I’m happy to send you more information about the project and submit a blurb/ad.

Thanks so much.

Best,
Dionne
———————–
Dionne Peacher
Duke University School of Medicine, MS3
919.668.0001
dionne.peacher@duke.edu

We have the following information about this in our web site:

What is pulmonary edema?

Pulmonary edema is the sudden filling of the lungs with fluid, generally thought of as being caused by a failure of the left side of the heart to pump properly.

What is the cause?

Pulmonary edema, characterized by cough, shortness of breath, and hemoptysis,  has been observed in both divers and surface swimmers.  This is a relatively rare condition whose etiology is uncertain, but would appear to be related to immersion.  Divers may dive for many years before first experiencing symptoms; thereafter, they may experience recurring episodes interspersed with periods of normal diving.

Characterization of
an attack!

Symptoms may begin on the bottom, during ascent, or shortly after ascent -chest pain  being notable in it’s absence, which helps to eliminate chokes as a diagnostic possibility.  Chest examination reveals rales, and chest radiographs show the classic pattern of pulmonary edema.  Significant decrease in arterial O2 may be present.  Symptoms and signs usually resolve spontaneously over 24 hours.

Precipitating causes

Episodes appear to be precipitated by factors that increase cardiac preload and afterload, including immersion in water (particularly cold water), heavy exercise, negative pressure breathing, and predive fluid overload.

What To Do

Get the diver out of the water
Elevate the head in the sitting position
Provide 100 % oxygen, mask if possible
Rotate tourniquets, if a qualified person is available.
Get the diver to an emergency facility as soon as possible.

Return to diving?

If a medical workup fails to reveal any intrinsic heart or lung disease - the problem may not reoccur with future diving. Examine the risk factors noted above and act accordingly.

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October 27, 2008

Anchor line Dermatitis

Filed under: Articlescubadoc @ 10:52 am
Here are images from a diver that ascended a fixed anchor line without gloves. This is a bullous eruption one week after diving on the Great Barrier Reef. This is thought to be due to reaction to hydroid growth on the line (nematocytes and coral scrapes).

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October 22, 2008

Man Overboard!

Filed under: Articlescubadoc @ 11:00 am

Water Related Personal Survival



With the many hundreds of boats actively moving about the waters of shores and bays there is always the possibility of accidentally falling into the water, capsizing or becoming the victim of foul weather.

Seven Steps To Survival
Survival at sea depends on the recognition that you are in danger of losing your life. There are commonly described “seven steps” to survival that may make a difference in the outcome of some rather terrible situations. Even an accident fairly close inshore in cold water can quickly lead to hypothermia and drowning. The seven steps to survival are: recognition, inventory, shelter, water, food, signals and play. Of course, flotation is a prerequisite for any survival after only a short time in the water. Other factors come into play, the most important of which is unmeasurable, “the will to live”.

The seven steps to survival include recognizing that you are in peril and realizing that what you are wearing constitutes a form of shelter. Water is kept in life rafts and you have keys, a mirror or plastic containers that might come in handy. Check to see what food might be floating around you and retrieve it if possible. Use signals in the form of mirrors, flares, colored objects or waving arms, suits or objects about to attract attention. Finally, “play” comes into action as you have memories, fantasies, prayer, tell jokes and get rid of your anger.

Capsizing is the number one cause of overboard situations and is the number two cause of fatalities in boating accidents. Other causes of overboard situations are heavy seas due to foul weather, urinating or vomiting over the side, sea sickness, alcohol or drugs, sitting on the outside of the deck (gunwales), moving about the vessel without holding on, boat making high speed or tight turns without warning, being knocked over by the sail boom and slipping on wet surfaces.

Personal Flotation Devices
It is hard to swim normal distances in an emergency situation. There is a rapid heat loss and incapacitation which causes inappropriate behaviors, such as, taking off clothes and shoes. A personal flotation device should be worn on the water at all times. Have you ever wondered why the Coast Guard always have their PFD’s on?

The floatation devices (PFD’s) that were previously mentioned keep your head up and out of the water and afloat even when you are unconscious. It’s best not to swim or exercise vigorously as this will increase the loss of heat. Position yourself 45 degrees toward the oncoming waves to avoid “surface drowning”. Gather together in a group if there are more than one person.

Prevention of falling overboard should always be uppermost in your mind. The PFD should always be worn when on deck. Hang on–”one hand for the boat and one for me” when working on a rocking boat. Don’t sit or lean on lifelines, stand on the bight of a line or sleep topside. Don’t sit on rails or gunwales without a lifeline or go on deck at night, in a fog or during heavy weather without a lifeline and tell someone else when you do. Don’t urinate or vomit over the side without a line. Walk and work in pairs on deck and wear proper footwear.

Finally, one must realize that the sea is an alien environment and even though we may think we are invincible, immortal and can even swim a little bit — when in the water out of sight of land we need to use all of our intelligence just to survive.
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October 18, 2008

Interesting Factoids from scubasworld.com

Filed under: Uncategorizedscubadoc @ 11:08 am


That over 100,000 cubic miles of seawater evaporates into the 
atmosphere each year. 



That the open circuit, compress air system (SCUBA) was coinvented by captain, Jacques Yves Cousteau, and french engineer Emile Gagnam in June 1943. 



That the oceans cover 70.8% of the earth. That’s about 140 million square miles (40 times the the size of the United States). 



That Lake Titicaca sits higher above sea level than any other lake, that’s 16,500 ft. 



That the Sperm Whale is the deepest diving mammal (8,000 ft). 



That Cetaceans longer than 20 feet are considered whales. 



That all toothed whales (Odontoceti) have only on blow hole, and the baleen whales (Mysticeti) have two blow holes. 



That blue Whales: average about 12 miles per hour; can hold up to 1000 tons of water and food in their mouths, and chest; and newborns can weigh up to 2 tons and measure 25 ft long. 



That the Sperm Whale is the largest brained creature in the world, 19.5 lbs. 



That Humpback Whales have the longest flukes of all whales, up to 14 ft long. 



That the Sai Whales are the fastest of all whales, reaching speeds of 35 knots. 



That most corals don’t live in depths below 200 ft, except for the black coral, which has been found in depths of 1,320 feet. 



That the Giant Squid has the largest eye in the animal kingdom, up to 12 inches in diameter. 



That Electric eels can produce up to 600 volts per shock, and about 2.5 shocks per min. 



That there are 7 different species of sea turtles: Leatherback, Loggerhead, Kemp’s Ridley, Hawksbill, and green seaturtle. 



That the Leatherback turtle is the largest and the deepest diving of all sea turtles. They can weigh up to 2,500 lbs and dive to 3,280 feet for up to 41 minutes. 



That the Seahorse has no stomach, no teeth, no ribs, and no scales. 



That the Right whale, and the Beluga whale have no dorsal fin. 



The Great Barrier Reef is the largest reef in the planet stretching for more than 1,200 miles. 



That all groupers begin life as females and after functioning as females, transform into males. So all large groupers are males. 



That Seaslugs only live about 8 months. 



That sharks have lived on earth for 400 million years. 



That female sharks’ skin is two to three times thicker than males, to endure the love bites during mating. 



That sharks can sense one part blood in 10 million parts water. 



That juvenile female blue sharks can store sperm from mating encounters for nearly two years until sexually mature enough to fertilize eggs. 



That sharks can turn their stomachs inside out and push it through their mouth to remove indigestible objects, then put it back into place. 



That the octopus’ brain is the largest and best developed of all invertebrates. 



That kelp beds can grow up to two feet per day, and attain lengths of 200

October 16, 2008

X-RAY MAG ISSUE #26 IS OUT!

Filed under: Uncategorizedscubadoc @ 10:48 am

Read it before your neighbour

X-RAY MAG issue #26 is out!

Did you know that reef fish are flourencent and that CO2 makes oceans noisier?

Did you ever wonder how the jellyfish got its sting, or What went through Pascal Bernabé’s mind when he dived to 330 meters?

Do you want to know how to pick Ocean-Friendly Sushi? Have you heard that explorers just found hundreds of undescribed species on Australian reefs, and that over 100 new species of sharks and rays have just been described?

Find out in the latest issue of X-RAY MAG.

 Hightlights in issue 26:

  • The Carribbean. Steve Jones visits Dominica, St Lucia and St Vincent.
  • GirlDiver. GirlDiver takes a look at the XScooter Dive Propulsion Vehicle (DPV) from a gentler perspective. Serious DPV diving for a girl? Is it too big? Too powerful? Too much of a “boy’s toy”? Check it out.
  • Bangaram Island. Charles Stirling tries out diving in India.
  • Diving to 330m. Pascal Bernabé reflects on his 330m World Record Dive. Conclusion: “Don’t do this at home, kids.”
  • Thetis Island, British Columbia. Barb Roy explores British Columbia’s Salish Sea.

Other stuff: Cedric Verdier dives HMS Victoria off Lebanon. Kurt Amsler talks about Night Photography. Fiona Ayerst reports on ‘Slide Finning’. Arnold Weisz visits the TAMAR Sea Turtle Project in Brazil. Portfolio: Artist and diver, Stéphane Braud, shares his art works of luminous blue underwater scenes painted under the waves!

New features on our website

  • Daily news. Stay updated with the goings-on in the dive world.
  • Widgets and feeds. Get X-RAY MAG issues and articles posted directly to your own website. By special request, we have created a number of feeds and widgets for our fans. Visit www.xray-mag.com/Feeds
  • Facebook. Join our group on Facebook
  • X-RAY MAG is also on LinkedIn
    This is a group designed for scuba divers at all levels, with any interests, which are seeking information and new perspectives on matters related to the underwater environment.

Our friends from DivePhotoGuide asked us to mention:
There are 1 or 2 spots left for their special trip to Socorro.
They also just relaunched UnderwaterCompetition.com. Check it out

Stay tuned for our live reports from DEMA:

Don’t miss out on the biggest event of the year. X-RAY MAG will be there, providing real time coverage with video broadcasts and still image galleries posted directly from the show floor daily!

www.xray-mag.com/DEMA2008

If you are going, please visit us at our booths, 1501-1503.

October 7, 2008

UNDERCURRENT ONLINE UPDATE FOR SUBSCRIBERS

Filed under: News, Publicationscubadoc @ 11:47 am

Undercurrent — Consumer Reporting for
the Scuba Diving Community since 1975
www.undercurrent.org

Dive News

October 7, 2008

You have received this message because you have signed up on our website to receive this email or you are a former subscriber or Online Member of Undercurrent . Removal instructions are below.

Serious Potential Danger with Apeks TX, ATX and XTX Second Stage Regulator Recall: 25,000 of these regulators, distributed by Aqualung USA, have been recalled by the Consumer Product Safety Commission (September 17). The manufacture forgot to include the diaphragm cover, a black, silver or yellow ring of plastic that sits on the main diaphragm. The diaphragm could get dislodged and lead to a diver sucking in water instead of air. The recall includes all second stages and octopuses purchased before July 2008 that have not had the authorized annual service. Take yours to an Apeks dealer for a visual inspection. You can remove the front cover to ensure the diaphragm cover is there and in its proper place. For details, contact Apeks at info@apeks.co.uk

Global Credit Crunch Affecting the Dive Industry: The first evidence coming our way that dive travel is severely affected by the financial crisis comes from Sunsea Cruises in Townsville, Australia. Next weekend they end their scuba/snorkel day cruises to the Great Barrier Reef. General manager Darin McDonald says the trips are no longer viable due to soaring fuel costs and global economic instability. “We’ve looked at other options of how we can save this business …but realistically we can’t see any other option but to close the doors.”

Best Value Dive Vacation: Read our review of CocoView, Honduras, where you can get unlimited diving and a good price. Of course our reviewer paid his own way and traveled anonymously. Click here.

Here’s a New Diver Hazard: Divers are told to avoid overhead environments for safety purposes, but now they are falling on us. As the U.S. highway infrastructure crumbles, so do its bridges. The east side of Blue Heron Bridge in Riviera Beach, Florida is a popular dive site., but it’s now a dangerous one due to large chunks of concrete falling from the bridge. Mark Kosarin, a dive instructor at the Force-E dive shop told WPTV, “I’ve heard it from more than one diver that pieces of the bridge are actually coming down.”

Holiday Gift for that Kid or Grandkid: Get them interested in diving and the undersea world with Underseas Encounters, a series of ten books from Scholastic, photographed by David Hall with text by children’s book expert Mary Jo Rhodes. Each book is an in-depth chapter on marine life, from crabs to dolphins to sea predators to sea horses They’re for ages 9-12 but younger kids can easily follow along. Paperback, 9 x 8 inches, $6.95 each. Order them or any other book at Undercurrent and not only will you get Amazon.com prices, but our profit will go directly to saving coral reefs.

Reserve Your Copy: The all new 2009 edition of The Travelin’ Diver’s Chapbook goes to press next week. Sign up now for an Undercurrent subscription and we’ll send you a free issue of the 488-page Chapbook, with more than 1,000 resort and liveaboard reviews and details about water temperature, best times to dive, whether there really is unlimited diving, if the food is palatable….everything you need to know. FOR FREE. You’ll get ten issues of Undercurrent, beginning with the October, 2008 issue, as well as online access to back issues and current travel reports from scores of destinations. Go to Undercurrent and sign up on the bottom right-hand side of the home page. Never seen a copy of Undercurrent? You can read a past issue for free from a link on our homepage (see “Read a Sample Issue“). Undercurrent is a 501 (c) (3) nonprofit organization.

North Carolina Dive Pioneer Dies: If you’ve dived North Carolina wrecks, there’s a good chance you went out with George Purifoy, owner of the Olympus Dive Center in Morehead City. Sadly, George, 63, died on September 14, collapsing on board his boat during a dive at the Queen Anne’s Revenge shipwreck site, where he was taking state archeologists to collect artifacts. His son Robert will continue running the dive center.

The World’s Biggest Shark Fight: Dubai is opening the world’s biggest aquarium in its Burj Dubai shopping mall on October 30, but it’s having problems with its sharks fighting and killing each other. That’s not surprising since there’s 400 sharks and rays swimming together in a 165-foot tank, but more than ten percent of their sharks have been killed by sand tiger sharks. Mall shoppers walk along a 270-degree see-through tunnel through the tank - at this rate, they’ll get ringside seats unless the aquarium takes action.

A New Wreck Dive in the Caymans: The Cayman Islands government plans to sink the decommissioned U.S. Navy ship Kittiwake as an artificial reef. Built in 1945, the 2,290-ton submarine rescue ship has been anchored for years among the rusting “Ghost Fleet” in St. Eustis, Virginia. The Kittiwake will head south as early as November, but no announcement yet on where its final resting place will be.

IN THE OCTOBER ISSUE:

* Pirates Point, Little Cayman, about as good as it gets;
* Yoga and Diving;
* Dive operator review; good spots in the Bahamas, BVI, boo on Buddy in Bonaire;
* New research on packing Rebreathers Canisters;
* Operators that refuse to go out when there aren’t enough divers, no matter how much you paid for the week;

* Avoiding Diver’s Vertigo;
* How the US falls short in Dive Death Investigations;
* How that morning hangover affects your diving;
* A Serious Rescue Device: GPS for Divers and which liveaboards provide them;
* Price Battle at Fiji’s Garden Island Hotel;
* Tidbits and tales of environmental degradation affecting diving;
* and much much more

Ben Davison, editor/publisher
Contact Ben

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October 4, 2008

Scan Detects Oxygen Levels in Tumors

Filed under: Article, News, Publicationscubadoc @ 11:05 am

Scan Detects Oxygen Levels in Tumors

April 23 (HealthDay News) — New research suggests that scientists are close to developing a simple way to measure oxygen levels in tumors, giving doctors a heads-up about what kind of treatment is best for individual patients.

The findings fit into an emerging trend of individualized treatment for patients with cancer instead of treating people the same way, said Dr. Mark Dewhirst, a professor of radiation oncology at Duke University Medical Center.

“If successful, [the trend] will revolutionize the way that we treat cancer,” said Dewhirst, who co-wrote a commentary accompanying the new study, published April 22 in the Journal of Clinical Investigation.

Scientists began realizing the important role of oxygen in tumors about 50 years ago, said study co-author James Mitchell, branch chief of radiation biology at the U.S. National Cancer Institute’s Center for Cancer Research. The scientists discovered that tumors with higher concentrations of oxygen were more susceptible to radiation, he said.

“Radiation damages cells by causing damage to DNA, and one particular type of damage renders the DNA molecule non-reparable,” Mitchell said. But less oxygen in the tumor allows tumor cells to survive more easily by making the DNA destruction process more difficult, he said.

According to Dewhirst, the same is true for chemotherapy drugs, which also don’t work as well when tumors have less oxygen.

Lower levels of oxygen create other problems, Dewhirst. “One would think at first that lack of oxygen would make tumors unhealthy and easy to kill,” he said. “But actually, the opposite happens — tumor cells that lack oxygen become more aggressive and more difficult to kill.”

Tumors with lower oxygen levels even spread more easily through the body, he said.

Doctors can check oxygen levels in patients by inserting a needle. But doctors can’t insert needles into some patients, and. in others, it’s difficult to insert the needle deep enough, Mitchell said.

In the new study, the researchers tested a scanning technique called pulsed electron paramagnetic resonance imaging and used it in tandem with magnetic resonance imaging. The study authors said they were able to successfully measure oxygen levels in tumors in mice by using the non-invasive technology.

“The imaging that is described in this study provides all of the information necessary to evaluate oxygen levels in tumors as well as to examine underlying causes for the lack of oxygen,” Dewhirst said. “The fact that all of the imaging is completely non-invasive provides the ability to perform this measurement more than once, (meaning) this could be used to monitor the effectiveness of cancer therapy.”

There are caveats, however. The research hasn’t reached the human testing level yet, and it may not work in people. “Scaling up the method to make it suitable for use in humans will be a significant challenge, but not impossible,” Dewhirst said.

For now, the plan is to launch more studies with animals to see if the technique works as a way to test cancer drugs.


SOURCES: Mark W. Dewhirst, DVM, Ph.D., Gustavo S. Montana professor of radiation oncology and professor of pathology and biomedical engineering, Duke University Medical Center, Durham, N.C.; James Mitchell, Ph.D., branch chief, radiation biology, Center for Cancer Research, U.S. National Cancer Institute, Bethesda, Md.; April 22, 2008, Journal of Clinical Investigation

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