Scubadoc’s Ten Foot Stop

June 11, 2010

Abstracts from Undersea and Hyperbaric Medicine Journal

Filed under: Article, Publication — admin @ 1:16 pm

Following are some abstracts from the March-April 2010 issue of the Journal of the Undersea and Hyperbaric Medical Society. These are copied from the public source, Medline.

Triage and emergency evacuation of recreational divers: a case series analysis.

Zeindler PR, Freiberger JJ.

Undersea Hyperb Med. 2010 Mar-Apr;37(2):133-9.PMID: 20462146 [PubMed - indexed for MEDLINE]Related citations

2.

Treating necrotizing fasciitis with or without hyperbaric oxygen therapy.

Hassan Z, Mullins RF, Friedman BC, Shaver JR, Brandigi C, Alam B, Mian MA.

Undersea Hyperb Med. 2010 Mar-Apr;37(2):115-23.PMID: 20462144 [PubMed - indexed for MEDLINE]Related citations

3.

Effects of hyperbaric oxygen therapy on the treatment of severe cases of periodontitis.

Nogueira-Filho GR, Rosa BT, David-Neto JR.

Undersea Hyperb Med. 2010 Mar-Apr;37(2):107-14.PMID: 20462143 [PubMed - indexed for MEDLINE]Related citations

4.

Hyperbaric oxygen therapy and age-related macular degeneration.

Weiss JN.

Undersea Hyperb Med. 2010 Mar-Apr;37(2):101-5.PMID: 20462142 [PubMed - indexed for MEDLINE]Related citations

5.

Conservative surgical management of necrotic tissues following meningococcal sepsis: case report of a child treated with hyperbaric oxygen.

Takac I, Kvolik S, Divkovic D, Kalajdzic-Candrlic J, Puseljic S, Izakovic S.

Undersea Hyperb Med. 2010 Mar-Apr;37(2):95-9.PMID: 20462141 [PubMed - indexed for MEDLINE]Related citations

6.

Intracerebral hemorrhage related to systemic gas embolism during hysteroscopy.

Guillard E, Nancy B, Floch H, Henckes A, Cochard G, Arvieux J, Arvieux CC.

Undersea Hyperb Med. 2010 Mar-Apr;37(2):89-93.PMID: 20462140 [PubMed - indexed for MEDLINE]Related citations

7.

Effects of cigarette smoking on tissue gas exchange during hyperbaric exposures.

Hart GB, Strauss MB.

Undersea Hyperb Med. 2010 Mar-Apr;37(2):73-87.PMID: 20462139 [PubMed - indexed for MEDLINE]Related citations

11.

The safe treatment, monitoring and management of severe traumatic brain injury patients in a monoplace chamber.

Gossett WA, Rockswold GL, Rockswold SB, Adkinson CD, Bergman TA, Quickel RR.

Undersea Hyperb Med. 2010 Jan-Feb;37(1):35-48.PMID: 20369651 [PubMed - indexed for MEDLINE]Related citations

12.

Hyperbaric oxygen ameliorates delayed neuropsychiatric syndrome of carbon monoxide poisoning.

Chang DC, Lee JT, Lo CP, Fan YM, Huang KL, Kang BH, Hsieh HL, Chen SY.

Undersea Hyperb Med. 2010 Jan-Feb;37(1):23-33.PMID: 20369650 [PubMed - indexed for MEDLINE]Related citations

13.

Left ventricle changes early after breath-holding in deep water in elite apnea divers.

Pingitore A, Gemignani A, Menicucci D, Passera M, Frassi F, Marabotti C, Piarulli A, Benassi A, L’Abbate A, Bedini R.

Undersea Hyperb Med. 2010 Jan-Feb;37(1):13-21.PMID: 20369649 [PubMed - indexed for MEDLINE]Related citations

14.

Repetitive breath-hold diving causes serious brain injury.

Tamaki H, Kohshi K, Sajima S, Takeyama J, Nakamura T, Ando H, Ishitake T.

Undersea Hyperb Med. 2010 Jan-Feb;37(1):7-11.PMID: 20369648 [PubMed - indexed for MEDLINE]Related citations

June 10, 2010

Image of cutis marmorata from the New England Journal of Medicine.

Filed under: Article, Publication — admin @ 10:23 am

Image of cutis marmorata from the New England Journal of Medicine.

Images in Clinical Medicine Kalentzos 362 (23): e67, Figure 1     June 10, 2010

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Figure 1
A 38-year-old man was transferred to the Diving and Hyperbaric Medicine Unit with decompression sickness 9 hours after a deep scuba dive to 54 m (177 ft). During the ascent, he had omitted decompression stops. On physical examination, there was evidence of paraparesis, hypoesthesia, and urinary retention associated with spinal cord involvement, as well as a characteristic rash (cutis marmorata) on the thighs and torso. Cutis marmorata is a dermal manifestation of decompression sickness. Initially, there is erythema accompanied by pruritus, and then the rash spreads irregularly and deepens in color. It develops a mottled appearance, with areas of pallor surrounded by cyanotic patches. During recompression, the rash resolves. Although cutis marmorata is not directly associated with complications, it commonly accompanies or precedes more severe illness involving the central nervous system or cardiovascular system and should be identified early in a troubled diver. The patient was treated with recompression in a hyperbaric-oxygen chamber. He was discharged 20 days later with resolution of the rash and full recovery of motor function. On follow-up 6 months after discharge, he remained free of symptoms.

November 13, 2009

Fitness to Dive, Age, Chapter 7

Filed under: Article, Publication — admin @ 4:56 pm

Problem — The Older Diver
To my knowledge there is no specified age limit to sport diving.

Diving Concerns

  • Condition Related


Most elderly divers are not capable of sustaining the work load required by all but the least physically demanding dives. The majority of elderly divers do not exercise regularly or adequately.

  • Treatment Related

Physical training can definitely minimize the decline in physical capacity in older divers.

  • Diver Related

Chronological age and physiological age can differ markedly; and each individual ticks to his own genetic clock.

Risk Assessment

  • Risk from the Condition

General health, agility and stregth decrease with age. Maximum heart rate, oxygen uptake and lung compliance decrease with age. [Parker, 'The Sport Diving Medical']
Good screening is necessary. Older divers have a higher incidence of chronic diseases; i.e., cardiovascular disease and chronic lung disease. Appropriate screening evaluations of the heart and coronary arteries with exercise testing is useful in older divers before instituting a diving program.
Osteoporosis (men and women) increases with age and increased incidence of fractures becomes a factor.

  • Risks from treatment

The older diver is more prone to be taking multiple drugs and medicines, some of which have effects that are adverse to diving. These should be listed and evaluated prior to allowing diving. See web page at http://scuba-doc.com/drugsdiv.htm .

  • Risks to the Diver

–Atherosclerosis affects the blood flow to the brain, heart, kidneys and limb muscles and therefore the function of these organs.
–Inability to self rescue due to decreased strength from muscle atrophy would be an important consideration.
–The older diver is more prone to hypothermia due to decreased tissue perfusion, decreased fat stores and decreased metabolism.
–Decompression sickness increases with age. [Edmonds] This may be due to decreased tissue perfusion and arthritic changes in the joints.

Advising the Diver

Most very old divers arrange for a personal dive guide to assist them in suiting up, donning gear, managing their entrances and exits from the water and accompanying them during the dive. The problem comes in getting the elderly to recognize when the time comes to ask for help! It’s hard to get an old diver out of the water!

  • Potential for injury from future diving

Myocardial infarction, heart failure account for a high percentage of deaths while diving. [Caruso]
Increased risk of pulmonary edema [additive effects of pulmonary edema of diving with borderline heart failure from intrinsic heart disease.
Increased risk of fractures [hip]

Increased risk of decompression sickness
Inability to self rescue or manage unexpected water movements [current, surges, wave action].

  • Modifiers

Regular Checkups.
Good physical conditioning
Absence of cardiovascular-pulmonary disease
Mentally alert
Diving Experience
Alteration of diving profiles with shallower, shorter diving, longer and deeper safety stops and longer surface intervals

  • Dive or not dive


If an older diver is in good physical condition and is mentally alert enough to do adequate problem solving at depth, then I would personally have no qualms in certifying him to dive.
The older diver is more likely to take fewer chances and to obey the rules. There are few 70 year-old ‘Buccaneers’!

Genetic clocks

To my knowledge there is no specified age limit to sport diving. Chronological age and physiological age can differ markedly; and each individual ticks to his own genetic clock. This having been said, most elderly divers are not capable of sustaining the work load required by all but the least physically demanding dives. The majority of elderly divers do not exercise regularly or adequately. Physical training can definitely minimize the decline in physical capacity in older divers.

Good screening necessary

Older divers have a higher incidence of chronic diseases; i.e., cardiovascular disease and chronic lung disease. Atherosclerosis affects the blood flow to the brain, heart, kidneys and limb muscles and therefore the function of these organs. Appropriate screening evaluations of the heart and coronary arteries with exercise testing is useful in older divers before instituting a diving program.

“I’m gonna live (dive) forever!”

If a 90 year old is in good physical condition, able to perform self and buddy rescue and is mentally alert enough to do adequate problem solving at depth, then I would personally have no qualms in certifying him to dive.

Ask for Help

Most very old divers arrange for a personal dive guide to assist them in suiting up, donning gear, managing their entrances and exits from the water and accompanying them during the dive. The problem comes in getting us old GCFD’s (“geezer-codger-fogy- duffers”) to recognize when the time comes to ask for help! It’s darned hard to get an old surgeon out of the O.R. – but doubly hard to get an old diver out of the water!

Older-Safer!

The obverse may also be operative; the older diver is more likely to take fewer chances and to obey the rules. There are few 70 year-old ‘Buccaneers’!
======================================================================

Diving Teens

Problem — Teen Age Divers
Sport diving imposes no legal limits on age, but most diver training organizations require candidates to be 15 years old for full certification. Training is provided to younger candidates who receive conditional certification until age 15. Ordinarily, the minimum age is 12; below this age seems to be quite young to us.

Diving Concerns

Condition Related

Variable rate of growth

The rate of development, growth and maturity of teens varies greatly and the age which they can take up sport diving is not uniform because of the psychological, intellectual and physical factors.

Maturity

Traits that are important - good judgment, responsibility, attention to detail and respect for rules are traits that may be slow to develop in some teens.

They should be physically able to manage the gear and carry out self and buddy rescue.
They must be able to understand the physics and biology involved with an ability to understand the dangers without being frightened.

Diver Related

Generally, the ages 14-16 are the times to start–gifted and mature teens may possess the above abilities sooner. Of course, there is always the exception to the rule, and many 11, 12 and 13 year olds who are physically and mentally capable of handling the heavy equipment and the training can be taught to dive.

Fitness considerations for young divers should be directed towards emotional maturity, ability to learn and understand the requisite physiologic, physical and environmental data needed for safe diving, and towards strength requirements necessary for handling diving equipment.

Risk Assessment

Risk from the Condition

Growth plates Young divers should use dive profiles which minimize risk for decompression sickness to eliminate concern for injury to growing tissues, such as the growth plates of bones. There are no good studies that indicate that the growth plates (epiphyseal plates) are a particular problem — but supposition that an area of increased vascularity “might” be more susceptible to bubbles. Since the damage that can be done to bone is in direct proportion to the length of time at depth, it would appear that these factors should be restricted in the growing teen-ager who has a life-time of diving ahead. Arbitrary depths and times have to be chosen to maintain low levels of onboard nitrogen; carefully monitored ascent rates with safety deco stops are definitely suggested.

Patent foramen ovale

It is known that the rate of closure of a patent foramen ovale is highly variable and a certain percentage of children will not have closed their defect by age 10. Because of this late closure in some individuals, it is possible that the percentage of children with PFO and right to left shunt could be even higher than the known rate of 25% in the general population. Programs allowing compressed surface-supplied air (SSA) to be provided to children as young as 5 would seem to be conducive to venous gas accessing the arterial circulation with disastrous central nervous system manifestations.

Risks from treatment
[Not apropos]

Risks to the Diver

In addition, the child should be physically, mentally and emotionally mature enough to rescue a ‘buddy’ in distress. This final caveat may be the ‘kicker’ that would prevent a 10 year old from becoming certified.

Physically, the young diver should be near 45 kg. (108 lb.) and 150 cm. tall (60 inches). He/she should be able to handle the bulky diving equipment and should be able to enter and exit the water without difficulty. Cold stress and buoyancy control pose special problems for the person of smaller statue, particularly on the surface in a suit. Gear size can be reduced and smaller tanks utilized.

Advising the Diver
Potential for injury from future diving
Possible injury from damaged growth plates
Possible increased risk for decompression illness from incomplete closure of PFO
Possible bone and joint injury from heavy equipment
Possible injury from trauma from entry and exit
Possible inury from cold stress
Possible injury from difficult buoyancy control due to size and poorly fitting thermal gear

Modifiers

Good physical conditioning, large size for age
Absence of cardiovascular disease [PFO]
Mentally alert and ability to understand the physics/physiology of diving
Alteration of diving profiles with shallower, shorter diving, longer and deeper safety stops and longer surface intervals
Motivation

Dive or not dive

Teen Classes

I strongly recommend that children take lessons with other teens-not in a mixed class with adults; and, that the instructor be knowledgeable about teens, and have a supportive style without the “macho” attitude that some instructors exhibit, often humiliating members of the classes.

Should not be ‘dragooned’ by a parent or sibling

Finally, there is nothing worse than being “dragooned” into diving. For those who are too small to use diving equipment comfortably, or who are too young intellectually there are alternatives to diving which will prepare them for diving later, ie., swimming in waves and currents, underwater swimming, swimming with fins or kickboard and snorkeling offers a great transition to diving for youngsters.


Links

DOWNLOAD Teen Age Diving
by Maida Taylor, MD

Scuba Board Thread About Children Divers
[Contains Undercurrent Article by DocVikingo]

Why I Do Not Train Kids
by Larry “Harris” Taylor, PhD

References

http://www.scuba-doc.com/download/Teendive.zip
This is a downloadable article by Dr. Maida Taylor

Bar-Or-O: Pediatric Sports
Medicine for the Practitioner from Physiologic Principles to Clinical Applications, NY, Springer Verlag, 1983

Bar-Or-O: Climate and the Exercising Child-a review: Int J Sports Med 1980, 1:53

Branta C, Haubenstricker J, and Seefeldt V: Age changes in motor skills during childhood and adolescence. Exerc Sport Sci Rev 1984,12:467

Dembert ML, Keith JF; Evaluating the Potential pediatric scuba diver. Am J Dis Child 1986; 140:1135-1141




Narrative:
Sport diving imposes no legal limits on age, but most diver training organizations require candidates to be 15 years old for full certification. Training is provided to younger candidates who receive conditional certification until age 15. Ordinarily, the minimum age is 12; the age of ten seems to be quite young to us.

Variable rate of growth

The rate of development, growth and maturity of teens varies greatly and the age which they can take up sport diving is not uniform because of the psychological, intellectual and physical factors.

Maturity

Traits that are important -good judgment, responsibility, attention to detail and respect for rules are traits that may be slow to develop in some teens.

Intellectual maturity

They must be able to understand the physics and biology involved with an ability to understand the dangers without being frightened.

Scuba training should be a completely inappropriate activity for a young person unless the interest in diving comes from a strong personal interest.


Generally, the ages 14-16 are the times to start–gifted and mature teens may possess the above abilities sooner. Of course, there is always the exception to the rule, and many 11, 12 and 13 year olds who are physically and mentally capable of handling the heavy equipment and the training can be taught to dive.

Fitness considerations for young divers should be directed towards emotional maturity, ability to learn and understand the requisite physiologic, physical and environmental data needed for safe diving, and towards strength requirements necessary for handling diving equipment.

Physically, the young diver should be near 45 kg. (108 lb.) and 150 cm. tall (60 inches). He/she should be able to handle the bulky diving equipment and should be able to enter and exit the water without difficulty. Cold stress and buoyancy control pose special problems for the person of smaller statue, particularly on the surface in a suit. Gear size can be reduced and smaller tanks utilized.


Growth plates

Children divers should use dive profiles which minimize risk for decompression sickness to eliminate concern for injury to growing tissues, such as the growth plates of bones. There are no good studies that indicate that the growth plates (epiphyseal plates) are a particular problem — just supposition that an area of increased vascularity “might” be more susceptible to bubbles. Since the damage that can be done to bone is in direct proportion to the length of time at depth, it would appear that these factors should be restricted in the growing teen-ager who has a life-time of diving ahead. Arbitrary depths and times have to be chosen to maintain low levels of onboard nitrogen; carefully monitored ascent rates with safety deco stops are definitely suggested.

Patent foramen ovale

It is known that the rate of closure of a patent foramen ovale is
highly variable and a certain percentage of children will not have closed their defect by age 10. Because of this late closure in some individuals, it is possible that the percentage of children with PFO and right to left shunt could be even higher than the known rate of 25% in the general population. Programs allowing surface-supplied air (SSA) to be provided to children as young as 5 would seem to be conducive to bubbles accessing the arterial circulation with disastrous central nervous system manifestations.

‘Buddy’ responsibility

In addition, the child should be physically, mentally and emotionally mature enough to rescue a ‘buddy’ in distress. This final caveat may be the ‘kicker’ that would prevent a 10 year
old from becoming certified.

Teen Classes

I strongly recommend that children take lessons with other teens-not in a mixed class with adults; and, that the instructor be knowledgeable about teens, and have a supportive style without the “macho” attitude that some instructors exhibit, often humiliating members of the class.


Should not be ‘dragooned’ by a parent or sibling

Finally, there is nothing worse than being “dragooned” into diving. For those who are too small to use diving equipment comfortably, or who are too young intellectually there are alternatives to diving which will prepare them for diving later, ie., swimming in waves and currents, underwater swimming, swimming with fins or kickboard and snorkeling offers a great transition to diving for youngsters.

October 24, 2009

Diving and ED Medications?

Filed under: Article — admin @ 9:51 am

Some thoughts on scuba diving while taking erectile dysfunction drugs.
‘Viagra, Levitra, and Cialis all belong to a class of drugs called phosphodiesterase (PDE) inhibitors. Taken an hour before sexual activity, these drugs work by enhancing the effects of nitric oxide, a chemical that relaxes smooth muscles in the penis during sexual stimulation and allows increased blood flow.

While oral medicines improve the response to sexual stimulation, they do not trigger an automatic erection as injections do. The recommended dose for Viagra is 50 mg, and the physician may adjust this dose to 100 mg or 25 mg, depending on the patient. The recommended dose for either Levitra or Cialis is 10 mg, and the physician may adjust this dose to 20 mg if 10 mg is insufficient. A lower dose of 5 mg is available for patients who take other medicines or have conditions that may decrease the body’s ability to use the drug. Levitra is also available in a 2.5 mg dose.

None of these PDE inhibitors should be used more than once a day. Men who take nitrate-based drugs such as nitroglycerin for heart problems should not use either drug because the combination can cause a sudden drop in blood pressure. Also, tell your doctor if you take any drugs called alpha-blockers, which are used to treat prostate enlargement or high blood pressure. Your doctor may need to adjust your ED prescription. Taking a PDE inhibitor and an alpha-blocker at the same time (within 4 hours) can cause a sudden drop in blood pressure.’

Side effects include a bluish tinge to the vision in some  – which should not have any untoward effect on divers. Also, reported possible more serious eye problems and increased stroke haven’t panned out in large studies. If your doctor finds you healthy enough to dive, then you should not have any qualms about using the medications before, during and after your diving trip.

An interesting recent finding is that increased levels of nitric oxide seem to reduce the incidence of bubbling during and after a dive. Thus, it would seem that taking daily doses of Cialis would decrease your chances of getting bubble related diving illnesses. See the abstract of a study printed below.

1: Med Sci Sports Exerc. 2006 Aug;38(8):1432-5.

Exogenous nitric oxide and bubble formation in divers.

Departments of Physiology, University of Split School of Medicine, Split, Croatia. zdujic@bsb.mefst.hr

PURPOSE: Prevention of bubble formation is a central goal in standard decompression procedures. Previously we have shown that exercise 20-24 h prior to a dive reduces bubble formation and increases survival in rats exposed to a simulated dive. Furthermore, we have demonstrated that nitric oxide (NO) may be involved in this protection; blocking the production of NO increases bubble formation while giving rats a long-lasting NO donor 20 h and immediately prior to a dive reduces bubble formation. This study determined whether a short-lasting NO donor, nitroglycerine, reduced bubble formation after standard dives and decompression in man. METHODS: A total of 16 experienced divers were randomly assigned into two groups. One group performed two dives to 30 m of seawater (msw) for 30 min breathing air, and performed exercise at an intensity corresponding to 30% of maximal oxygen uptake during the bottom time. The second group performed two simulated dives to 18 msw for 80 min breathing air in a hyperbaric chamber, and remained sedentary during the bottom period. The first dive for each diver served as the control dive, whereas the divers received 0.4 mg of nitroglycerine by oral spray 30 min before the second dive. Following the dive, gas bubbles in the pulmonary artery were recorded using ultrasound. RESULTS: The open-water dive resulted in significantly more gas bubbles than the dry dive (0.87 +/- 1.3 vs 0.12 +/- 0.23 bubbles per square centimeter). Nitroglycerine reduced bubble formation significantly in both dives from 0.87 +/- 1.3 to 0.32 +/- 0.7 in the in-water dive and from 0.12 +/- 0.23 to 0.03 +/- 0.03 bubbles per square centimeter in the chamber dive. CONCLUSION: The present study demonstrates that intake of a short-lasting NO donor reduces bubble formation following decompression after different dives.

So – my take on all this is that it really won’t cause any problems, but would possibly be beneficial in addition to it’s wanted sexual activity.

October 19, 2009

Diving Medicine – A Review and Update

Filed under: Article — admin @ 12:59 pm

Your attention is directed to an article in the American Journal of Family Practice, printed in full and free. This is written by James Lynch and Fred Bove and provides the latest in thinking about management of Diving problems. There is an excellent reference listing and numerous links in the article. The article is located at http://www.jabfm.org/cgi/content/full/22/4/399#SEC13 .

September 29, 2009

Helium Speech – An Astronaut Calls the President

Filed under: Article — admin @ 1:45 pm

Helium Speech – An Astronaut Calls the President of the United States

Jolie Bookspan, M.Ed, PhD, FAWM

When you take a breath from a helium balloon and speak, your voice rises humorously. What happens when an astronaut does the equivalent and calls the President of the United States?

In 1965, Sealab II replaced Sealab I, 62 meters (200 feet) down on the ocean floor (photo at left). Sealab II was sometimes called the “Tiltin’ Hilton” because of the slope of the site. Teams of “aquanauts” lived and slept inside, dry, breathing air pressurized to that depth. The Sealab project was under command of Dr. George Bond, Captain, U.S. Navy Medical Corps, affectionately called “Papa Topside.”

NASA Astronaut Scott Carpenter (photo right) spent a record 30 days in Sealab II. After spending that much time at that depth, specific protocols of changing the breathing mixture and the pressure are needed to avoid problems from the dissolved gas that was absorbed while breathing the air at SeaLab pressure. Commander Carpenter did that inside a special decompression chamber, while breathing an air mixture containing helium. Yesterday’s post How To Stay Underwater For A Month explains.

Helium changes heat transfer both inside and outside your body, and changes how fast sound can travel. Sound travels faster through helium than through air. That is the “Donald Duck” effect. People who inhale helium from a balloon and speak on the exhale have a distinctive humorous voice change. Funny voice is temporary, lasting only as long as helium is passing the vocal apparatus. (Helium can’t support life. Don’t continuously breathe balloon or other helium source to get a few laughs talking funny.)

I had heard from my Navy friends that an old recording existed of Commander Carpenter trying to phone President Johnson for a formality of congratulations while still inside the recovery chamber breathing the helium mix.

Recently, my colleague Dr. Derrick Pitts, Director of the Fels Planetarium at the Franklin Institute in Philadelphia, and I were talking about space and underwater habitats. He told me that the recording of Commander Carpenter had been found, restored, and was available through NPR National Public Radio.

Click LBJ & the Helium Filled Astronaut to read the short story and listen with RealAudio in 14.4, 28.8, or G2 SureStream. (If link is not clickable, try http://www.npr.org/programs/lnfsound/stories/991015.stories.html).

The description lists the event as 1964, but I think it would have been 1965. It doesn’t matter. Enjoy the recording.

Over this summer, I hope to write you some interesting stories about decompression, scuba, space research, cool people involved, and my work living under the sea. Until then, here are related stories:

September 17, 2009

Diving in Polluted Waters

Filed under: Article — admin @ 10:50 am
Diving in Polluted Waters

The Problem
Over the past ten to fifteen years the diving population has become sensitized to the potentially hazardous presence of pollution in the sea.  The ocean has been a traditional dumping ground for many types and degrees of pollutants.  Several years ago a Los Angeles Times article indicated that 2000 U.S. beaches were closed due to sewage spills.(1993).  California, as usual a leader, had 745 closures with 588 occurring in Southern California.  Consistent and regular monitoring would have probably  fond many more contaminated beaches needing closure.  There is a definite lack of any standardized program for monitoring our waterways; particular areas of concern are harbors and similar areas which do not “flush” well, rivers, especially those with high levels of industry on the shores, sewage outfalls which go out to sea but are often overloaded and areas which have the deposits of soft, silty materials dropped as the currents reduce their velocities in dispersal areas.  It has been estimated that there are on the order of 15,000 chemical spills that enter our water areas each year in the U.S. alone.  The contaminated areas are growing and now include many recreational diving areas as well as scientific study sites and search and rescue operations.

The health consequences of the water pollution have not been quantified by careful study but many local health professionals are concerned with infectious and carcinogenic disease potential for patients who are ocean swimmers, lifeguards and divers. Until adequate epidemiologic data is available the recourse would appear to be logically focused upon conservative practices in selecting dive sites and conditions.

This increase in areas of pollution is a worldwide problem and has affected many diving operations. Diving in polluted water requires that certain precautions be taken, and, in some instances, the use of sophisticated equipment and procedures.  Avoiding diving in areas with high potential for pollution, particularly after heavy rains is fundamental in urban or industrialized areas.


The main problem centers around the fact that bacterial, viral and chemical hazards can affect the human body by skin contact and entry through orifices.   The following list was produced in the NOAA Manual and the details were obtained from the medical literature.

Vibrio – 34 species of this family of bacteria are known and cholera and El Tor vibriones are among those known to be pathogenic to man.  Cholera vibriones have recently been found in Santa Monica Bay in California and have raised concerns although it is not known to have produced any disease. Other vibriones may be anaerobic and produce disease states such as purulent otitis, mastoiditis, and pulmonary gangrene.  V. Proteus found in human fecal material is a common cause of diarrheal disease.  V. Vulnificus is found in sea water.

Enterobacteria
Escherichia – found widely in nature, occasionally pathogenic to man, produces carotenoid pigments and can often be recognized by the orangish pus.  E. Coli,. which has some pathogenic strains is often found in fecal material: and can produce urinary tract infection and epidemic diarrheal disease.

Shigella – produces dysentery

Salmonella – 1000 serotypes, ingestion can produce gastroenteritis including food poisoning, typhoid and paratyphoid.

Klebsiella – can produce pneumonia, rhinitis, respiratory infection.

Legionella- causes Legionnaires disease and Potomac fever.  Perhaps inhibited in salt water.

Actinomycetes – causes a “ray fungus” actinomycosis, an infectious disease in man which inflames lymph nodes, develops abscesses, can drain into the mouth causing damage to the peritoneum, liver and lungs.

Pseudomonas- pathogenic to man, “blue pus” formed by some pseudomonas infections. This can lead to a wide variety of infections including wound sepsis, endocarditis, pneumonia and meningitis. It is known to flourish in dark, warm, damp places, i.e., inside hoses, bladder compartments and similar places that are not cleansed after being infiltrated by contaminants.

Viruses – infectious agents which can result in fevers (frequently severe), mononucleosis, and a wide range of disease states.

Parasites – many types with all manner of effects, all bad, can are found in polluted water.

Chemicals -  There are over 15,000 chemical spills in the U.S. waterways each year and many of these are releasing chemicals that are incompatible with man and the equipment that is worn.


Prevention
As detailed information becomes available on this issue divers will become sensitized to the need for preventive measures before, during and after diving.  At present the scientific and public safety diving communities are developing techniques for isolating the diver from the potential problems and decontaminating all exposed elements of the diving equipment.  It appears eminent that the recreational community will feel the need to exert greater care in the future.

It is becoming increasingly important to develop an understanding of the variations in the local conditions to which individuals expose themselves.  Some areas become particularly hazardous following heavy rains, hot weather and windstorms.  Local health authorities can usually be called for advice regarding any tests that have been performed and the results.  They should also be able to identify areas of high concentrations of pollutants that should be avoided.

When diving in areas where pollution is suspected or expected the following issues are worthy of evaluation.

1. The individual diver should consider the need for appropriate vaccinations and inoculations.  Many of the diseases can be avoided if the individual has taken the appropriate “shots”.  A few that appear worthy of consideration:
Hepatitis A and B
Cholera
Polio
Tetanus
Typhoid, Smallpox and Diphtheria

2. Pollution and filth are often associated. If the water contains obvious trash and garbage it is quite probably an unhealthful diving environment and another location should be selected.  If the water looks nasty it probably is nasty!!

3. Many diseases have an incubation period before they exhibit symptoms.  Medical advice is as close as the phone and early diagnosis and treatment can sometimes be improved if the Doctor understands that an individual may.have been submerged in polluted water.

4. Information on chemical spills can be obtained from the Chemical Transportation Emergency Center (1 800 424 9300 US).

5. “When in doubt- Check about”

A basic procedure if one feels they must dive in high risk water involves reducing the exposure of the diver.  NOAA has pioneered a sophisticated SOS (suit over suit) system that will virtually isolate the diver from any contact with the water.  This system is somewhat complex inasmuch as it requires complete system integrity from the times the diver dresses out until the system has been decontaminated following the dive.  Strict procedures are followed to ensure that the divers body does not contact the fluid in which it is immersed.

Previously, many public safety divers wore a  single dry suit and a full face mask during their dives. However, Stephen Barsky now states that Full-face masks only provide minimal protection and should only be used in environments where the pollutants are known, and do not pose a threat of death or permanent disability. In environments where the pollutants are not known, or where they lead to death or permanent disability, a helmet should be worn connected to a mating dry suit with mating dry gloves. This is considered the standard today.” (See Reference below)

If good seals are involved and the diver is effectively rinsed, scrubbed down and rinsed again prior to breaking any existing seals, the probability of exposure to the pollutants can be minimized.  Special care must be taken to clear hoses and fittings that interface with the life support system.  A failure to rinse bladders and hoses which may later be linked to the divers mouth or lungs could provide a path to the host days after the dive.  The use of snorkels, alternate air sources, oral inflation devices and hose connections should all be given careful attention since the can carry contaminants directly into the mouth.  Positive pressure, “self bailing” breathing systems have definite advantages in that they resist flooding.

Recreational divers maybe well advised to place their regulator in their mouth and their mask over their nose before entering suspect water and keeping it there until they have safely exited the water where they can remove the regulator without needing to replace it.

Polluted water is a fact of our lives.  The degree of pollution can only be mitigated through education and the “upstream” elimination of the sources of the contaminants.  The attitude that careful rinsing of diving gear is a waste of time “cuz its just going to get wet again next time it is used” should probably be replaced with the attitude that one should begin every dive with clean gear.


LINKS To Pollutant Testing

Utah Bureau of Environmental Chemistry and Toxicology
http://hlunix.hl.state.ut.us/els/chemistry/

Adapted from Glen Egstrom, Ph.D
Medical Seminars, Inc. 1992

Other References:
Colwell, et.al. Microbial Hazards Of
Diving In Polluted Waters, Maryland Sea Grant
Publication UM-SG-TS-82-01.

Diving in High-Risk Environments, 3rd Edition
by Steven M. Barsky
Amazon.com
Paperback – 197 pages 3rd edition (December 15, 1999)
Hammerhead Press; ISBN: 0967430518


September 1, 2009

Diving After Bleomycin Treatment

Filed under: Article, Publication — admin @ 10:26 am

We have received a question from a diver who is a survivor of cancer treatment using bleomycin.

“I am a 32 year old Ovarian (Dysgerminoma) Survivor.  Prior to my diagnosis I was active and enjoyed scuba diving.  I did sustain some damage to my lungs (from Bleomycin).  I have bleomycin induced lung injury.

I want to dive, my pulmonologist is not sure what to tell me.  There are no studies out there for this situation.  Is it safe?  How can I find out?”

Answer:

There are some published articles in the medical literature about this problem – although there are not any ’studies’. There is a very good summary that outlines the risks involved in diving after bleomycin treatment in a summary of the effects of bleomycin on the surgical patient and on the scuba diver in the form of a letter to the editor by R.M. White.

Since you have unfortunately developed pulmonary fibrosis, you would be at risk for pulmonary barotrauma and oxygen toxicity from elevated pressures of diving and from hyperbaric oxygen treatment should that become necessary.

Because of these increased risks, it would be wise for your doctor to disallow diving. Your best bet for enjoyment of this wonderful sport would be to become the world’s best snorkeler – visiting shallow reefs that are always present in good diving locations. Visibility is better, it’s easier to access and best of all it’s less expensive.

Hyperbaric Oxygenation Article on Medscape.

Filed under: Article, Publication — admin @ 9:45 am

I would like to call your attention to a very good article on the Web about Hyperbaric Oxygen Treatment. This is located on the eMedicine page of Medscape, is well written and documented and would be well worth your while to read, download or copy and use in your Hyperbaric practice.

The article contains history, actions, contraindications and indications for the use of the modality.

Click here for access.

June 27, 2009

Problems With Moving Water

Filed under: Article — admin @ 10:47 am
Problems With Moving Water


Avoid this Disaster

Accidents caused by divers being carried away by currents have been reported since the early days of diving in the 1950’s. Most of us have heard about the horror story of the five Japanese divers, who came up after a very beautiful and enjoyable current dive off Peleliu, only to find that they had not only missed their boat but had missed the end of the island. All of these divers died after a prolonged float in what must have been a strong current. The current was not at fault, however, but poorly qualified dive operators and faulty equipment, an uncertified diving guide, a small faulty single engine vessel without a radio and novice divers –all pointed toward this disaster. See Guidelines for the Abandoned Diver

Diving in currents is easily one of the most enjoyable – but can be one of the most dangerous dives that a diver encounters. It is a low energy high speed trip that allows you to see much more of the rapidly passing reef. The flip side of this is that you miss a lot of small life, and the hazards of loss of control and any efforts to work against the currents are high energy and stress producing. Recognizing that a problem exists is the first thing a diver has to face. Divemasters usually are on top of the problem and brief you appropriately.


Signs of A Current

Each diver can detect signs of current, such as:

1). fast moving surface water;

2). which way the boat is facing (depending on whichever is the stronger, the current or the wind);

3). movement of floating material on the water or in the water;

4). movement of divers away from the boat rapidly on entry;

5). bubbles moving away from a diver at an angle underwater;

6). if the plant life and soft coral underwater are laying down.

The contour of the ocean bottom will change currents, often dramatically. A diver can adjust his speed by moving to the bottom, slowing behind coral heads and outcroppings or holding on to permanent objects, all the time presenting the smallest frontal surface area to the current. Because of a “boundary layer” condition, water molecules that are closest to a surface move the slowest due to their nearness to the surface. Other areas of calmness are areas behind obstacles and the sides of walls. Getting close to the bottom and using your finger or dive knife to stabilize you is usually all you need to hold your position.

As the diver moves through the water column he encounters resistance-and this increases by the square of the velocity of the current as it passes over the body. As a diver works against the current along the bottom, a good indication of the amount of work being performed is by monitoring the respiratory rate, this rising exponentially as exertion increases. “Bottom crawling” is a technique that may have to be used when the swimming exertion level rises. This is easily done in rocky areas but can be a real challenge in sandy bottoms-where a good dive knife comes in handy as an anchor.

If conditions exist so that exertion levels continue to rise, it’s better to surface, inflate and wait. Here is where a safety sausage comes in handy. This is an inflatable, long red plastic tube that juts above the water 6-7 ‘ and can be easily seen as much as a half a mile or more. Shining a flashlight in the bottom of the sausage at night provides a long red light that can be seen at a great distance.

Surface floats are other techniques used in diving in currents. A line attached to a float and to a diver give two advantages; the dive group is marked for the boat operator and any tired or nervous divers can hang onto the line and rest. When drifting free without a line, the boat operator relies on visualizing the diver’s bubbles for location; a surface chop can make it difficult for the boat operator to see the divers bubbles,

Strong currents can rip away a mask or snorkel when turning sideways or looking up. Snorkels do better stored in the BC or under a leg strap underwater so as to reduce drag on the mask. Place a little extra tension on mask straps if strong currents are expected.

The dive group should have a clear understanding of exiting and entering the water in conditions of current. Divers should try to let the current work for them by initiating dives into the current on the first part of the dive and planning the return with the current. Float lines are essential for an orderly entry for the divers to hold position for descent and ascent, otherwise divers will be strung out too far apart for a safe dive. Entries should be timed so that there will be no stragglers and the descent be made under control. Exits are also planned so that the float line can be used to pull against the current rather than having to swim against it.

Currents are usually generated by wind and tides or a combination of the two. Predicting what you will encounter generally depends on using information from the local weather service combined with tide information from local dive operators. In certain areas, such as “The Great White Wall” in Fiji and “Blue Corner” in Palau, the currents are almost always due to tidal action and are fairly predictable. One should always go with local experience in making decisions regarding diving into currents.


Surges

Underwater motions occur in areas where swells are forced against a barrier of some sort, such as a beach, wall, rock, or wreck. A surge is a to-and-fro action complicated by indentations such as caves, rocks or large holes in wrecks. Surges can be used to aid in your movement, carrying you forward in one direction where you can stabilize yourself as the surge retreats, and move forward again with the next surge. They are also dangerous since they create huge forces that can carry you into places that you don’t want to go. Divers should remain distant from diver-size holes in wrecks and caves and learn to use surges as a method of aid in movement, either upward to get back into the boat or to move onto a ledge.

WRECKS

Wrecks create special problems with currents. Frequently the boat will anchor on the wreck, playing out enough scope so that divers can easily descend on the line. A tag line is helpful placed between the anchor line and the stern of the boat, facilitating the descent from the dive platform. Divers who lose contact with the line run the risk of being swept away from the wreck and the diveboat, sometimes requiring rescue after coming up predictably exhausted from fighting the current.

Adapted from Glen Egstrom, Ph.D.
Medical Seminars, Inc
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