Name: Doc Vikingo
Bio: Doc Vikingo has been scuba-certified for more than 35 years and has dived all over the world. He is a practicing doctor in the Washington D.C. area and has held positions at several major hospitals. With an interest in diving medicine, Doc serves as administrator for Scuba Clinic Online and was formerly the Medical moderator at ScubaBoard.com. Doc is a past columnist for Rodale's Scuba Diving and now writes for Undercurrent, Alert Diver and other dive publications.
Posts by DocV
Swallowing Air While Diving
July 9th, 2010
(Q) Hello DocVikingo,
I tend to swallow air while diving and get gas with cramping and belching upon ascent. This is very unpleasant. Anything I can do? Thanks. t-d-g.
(A) Hi t-d-g,
Swallowing air during a dive, called aerophagia, is not uncommon in newer divers. Also, divers who are overweight seem to have an increased frequency of such complaints.
As you’ve noticed, air in the stomach at the time of ascent will expand according to Boyle’s Law. Painful abdominal cramps, along with burping and flatulence, can ensue. More seriously, given sufficient trapped air and a rapid enough ascent, the stomach actually can rupture.
Prevention is the best management of the problem. To reduce the likelihood of swallowing air, or otherwise getting unwanted gas in the stomach: perform Valsalva maneuvers with the head up, not down; don’t drink carbonated beverages or eat heavy meals prior to diving; don’t chew gum or anything else while diving; make sure the second stage is properly tuned (too low a cracking pressure is the real worry here); and, concentrate on taking, smooth, long and regular inhalations and exhalations.
Regards,
DocVikingo
This is educational only and does not constitute or imply a doctor-patient relationship. It is not medical advice to you or any other individual and should not be construed as such. Consult with your physician before diving.
Diving & Post Traumatic Stress Syndrome
June 21st, 2010
May 18, 2010
“Dear Dr. Vikingo. I’m an already certified 600+ dive diver who after tours in Iraq and Afghanistan with the Military developed PTSD. For the last 2 years I have been in therapy and have done inpatient treatment. I’m now stable and have no side effects. I’d love to get back to diving but need to do it right I take depakote blood test are fine and citalopram. When would you suggest I talk to my Drs. about this? I have been through CBT therapy, Individual, and group therapies. Honestly the most peacefull times of my life have been while I was diving.”
(A) 05.20.10
“Hi DD,
Per the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision, (DSM-IV-TR), 17 possible symptoms that can develop following the experience of a traumatic event are divided into three clusters.
Re-Experiencing Symptoms
-Frequently having upsetting thoughts or memories about a traumatic event.
-Having recurrent nightmares.
-Acting or feeling as though the traumatic event were happening again, sometimes called a “flashback.”
-Having strong feelings of distress when reminded of the traumatic event.
-Being physically responsive, such as experiencing a surge in your heart rate or sweating, to reminders of the traumatic event.
Avoidance Symptoms
-Making an effort to avoid thoughts, feelings, or conversations about the traumatic event.
-Making an effort to avoid places or people that remind you of the traumatic event.
-Having a difficult time remembering important parts of the traumatic event.
-A loss of interest in important, once positive, activities.
-Feeling distant from others.
-Experiencing difficulties having positive feelings, such as happiness or love.
-Feeling as though your life may be cut short.
Hyperarousal Symptoms
-Having a difficult time falling or staying asleep.
-Feeling more irritable or having outbursts of anger.
-Having difficulty concentrating.
-Feeling constantly “on guard” or like danger is lurking around every corner.
-Being “jumpy” or easily startled.
Clearly many of these could pose a significant danger to diving.
All divers must show attention, concentration, decision making capacity, impulse control and behavioral modulation that are fully adequate to meet the demands of scuba. These faculties may be compromised in persons diagnosed with PTSD and treated with mood stabilizers such as the SSRI citalopram (Celexa) and the anti-convulsant divalproex sodium (Depakote).
Before returning to SCUBA, it would be prudent that: (a) mental status examination demonstrates the condition to be well controlled; (b) the diver who is taking medications has been on them for an extended period and side effects dangerous to scuba are neither reported nor observed upon careful examination; (c) there are no other contraindications, mental or physical, in the clinical picture; (d) the diver feels he is up to it and fully comprehends any additional risks; (e) the diver has been cleared for diving by his physician and makes full disclosure to the dive op (which likely will want to see written clearance) and to his/her dive buddy.
Best of luck and thanks for serving your country.
Regards,
DocVikingo
This is educational only and does not constitute or imply a doctor-patient relationship. It is not medical advice to you or any other individual and should not be construed as such. Consult with your physician before diving.”
Is there a disconnect between DAN’s Mission/Vision Statements and the content of Alert Diver magazine?
May 29th, 2010
The new quarterly Alert Diver, published by Stephen Frink and company, unarguably is a handsome magazine that makes its prior incarnation appear a bit of an ugly stepsister. Then again, it now appears to have a lot more money to play with. But, is it straying from DAN’s stated raison d’être?
The DAN Mission/Vision Statements can be read in full here, but I’ll highlight the most relevant content below (bold script mine): [View the issue online here, or perhaps first go here and choose the digital edition in upper right corner -- DSE, webmaster]
- “About DAN: Divers Alert Network (DAN) is a 501(c)(3) non-profit medical and research organization dedicated to the safety and health of recreational scuba divers and associated with Duke University Medical Center (DUMC).”
- “Founded in 1980, DAN has served as a lifeline for the scuba industry by operating diving’s only 24-hour emergency hotline, a lifesaving service for injured divers. Additionally, DAN operates a diving medical information line, conducts vital diving medical research, and develops and provides a number of educational programs for everyone from beginning divers to medical professionals.”
- “DAN’s Mission Statement: DAN helps divers in need with medical emergency assistance and promotes diving safety through research, education, products and services.”
- “DAN’s Vision Statement: Striving to make every dive, accident- and injury-free.”
In the above material I was unable to find any description of DAN’s/Diver Alert magazine’s role in advancing u/w photographic skills, travel location reviews, marine conservation, dive gear and the like. Yet, the current Spring 2010 edition, while admittedly including a number of diving safety and medicine pieces, is filled with such off-topic articles, several of them Feature pieces. For example:
Photography (the most egregious examples):
Pushing the Envelope (Three Advanced Photo Techniques Taught by Pros Who Perfected Them), pp 68-75
Imaging, pp 76-87
Travel:
Anacapa Island, California, pp 24-25
Alger Underwater Preserve, pp 26-27
Cayman Blue, pp 52-59
The Essentials of the Maldives, pp 60-67
Conservation:
Dive Slate, pp 12-14
Water Planet, pp 88-89
Gear:
Backplate Buoyancy Systems, pp 34-36
Now, I’m not saying that such pieces don’t make for an interesting, entertaining, flashy, and rather expensive publication, or that some folks don’t much enjoy it.
The issue is, “Are such articles consistent with the Mission and Vision Statements of DAN and a proper use of members’ dues?” “Are they the most appropriate use of limited DAN resources given how the organization represents itself to its members and the public?” “Does their primary purpose seem to be the advancement of medical services and research related ‘…to the safety and health of the recreational scuba diver’?”
Just askin’
DocVikingo
Fizzy drinks and DCS.
May 11th, 2010
Not all IDC students are created equal.
(Q) 04.11.10
Hey DocV,
During my girlfriend’s IDC, a candidate talked about the dangers of drinking fizzy drink (like coca cola) and then diving. He was specifically saying that the bubbles in the drink would increase the chances of a DCS hit.
For me, the bubbles are in the stomach which is enclosed and away from the blood stream so apart from the possible changes to metabolism due to the caffeine and sugars, it shouldn’t be a factor?
Any thoughts?
JB
(A) 04.12.10
Hi JB,
Yes, I think one of the IDC candidates in your g/f’s class still has some important concepts to master.
For openers, with the exception of a very small number of nitrogenated beers, mostly European, the bubbles in carbonated drinks, including all sodas, are composed of carbon dioxide (CO2), not nitrogen (N2). And of course it is the latter that’s the gaseous culprit in DCS in recreational divers.
And you are right –- gas bubbles cannot enter the circulatory system from the GI system under anything resembling normal circumstances. It is theoretically possible that bubbles could enter blood circulation as a result of gastric or intestinal barotrauma, but it would be an extraordinary situation where expanding bubbles would tear the GI wall rather than be expelled from one or the other ends of the alimentary tract (i.e., flatulence or belching).
Small amounts of gas from swallowed CO2 bubbles might pass into venous circulation in a dissolved state. However, if this occurred the gas would be rapidly dispersed in the blood coursing to the heart and off-gassed without issue. C02 readily binds to the hemoglobin in venous red blood cells and is then transported to the lungs where it is exhaled.
You also mention the caffeine common to carbonated cola drinks. While that chemical does mildly increase the excretion of urine, this is only in amounts much greater than contained in a can or bottle of normally caffeinated soda. Given sensible consumption, caffeine’s contribution to dehydration, and therefore possibly to DCS, is negligible.
As for the sugars in sweetened soft drinks, these may promote obseity, diabetes and tooth decay, but in anything remotely resembling sensible quantities make no meaningful contribution to dehydration.
Regards,
DocVikingo
Feel like you’re still on the boat after diving?
April 18th, 2010
(Q) Mar 11, 2010
“Hello Doc,
I got back from Mexico yesterday, was diving there for 3 days. Didn’t have any problems. After the 3 days of diving I felt like on a boat constantly and still feel like it. I have a light headache as well. Please tell me if I should go to the doctor. Is that normal? I noticed I have a high temperature as well (37.8 Celsius degrees) and feel like I have flu.”
(A) Mar 12, 2010
“Hi k–g,
The condition described could be what is called “reverse seasickness,” “land sickness” or “mal de debarquement,” although it typically takes more than just 3 days of land-based diving to trigger this unpleasant malady.
DAN has the following to say about land sickness: “And what about the reverse of sea sickness: sickness on land? It does happen. After you have finished that 10-day ‘trip of a lifetime’ aboard a liveaboard and have stepped onto solid ground, you may suddenly feel funny and maybe even sick. What happened? ‘Land sickness’ occurs when you return to dry land after becoming adapted to an environment in constant motion. Your brain has become accustomed to the new input from increased motion. Suddenly, the motion stops. The abrupt change will promptly produce the same symptoms as originally felt upon going to sea.”
Mal de debarquement, technically a more serious and longer lasting condition, is discussed here:
Mal de Debarquement, or “MDD,”
http://www.dizziness-and-balance.com/disorders/central/mdd.html
Alternatively, middle or inner ear barotruama or inner ear DCS also can manifest with a similar sensation, but typically involve other symptoms as well, such as decreased hearing, ear discomfort, vertigo or tinnitus.
Given a fever of 37.8C/100F and feelings of having the flu, my guess is that the sensation described is related to an infection of the inner ear, such as viral labyrinthitis, that results in feelings of disequilibrium.
It would be wise to consult an ENT if matters don’t improve in a day or two.
Regards,
DocVikingo
This is educational only and does not constitute or imply a doctor-patient relationship. It is not medical advice to you or any other individual, and should not be construed as such.
