by Kevin Denlay, IT#54
Guadalcanal, just the name stirs emotion. Guadalcanal, the site of the first American amphibious counter-offensive against the Japanese in the Second World War. Guadalcanal, the then unheard of island where the Americans (along with the Australians at Kokoda in Papua New Guinea) destroyed the myth of Japanese invincibility in the Pacific. Guadalcanal, where the advancing Japanese war machine ground to a screeching halt! Of 36,000 Japanese troops to go ashore on what they came to call "Shih Shima" or "Death Island" only 13,000 were eventually evacuated. After Guadalcanal the Japanese made no more advances in the Pacific, period! Although the American Navy suffered what is considered to be their greatest ever 'blue water defeat' in the campaign for Guadalcanal, (in the Battle of Savo Island) they constantly thwarted the Japanese efforts to destroy Henderson Field (the airfield taken from the Japanese at the beginning of the campaign and the key to overall supremacy in the South Pacific) and re-supply their increasingly isolated troops fighting the US First Marine Division on that then god forsaken island. As Napoleon once remarked, "Between a battle lost and a battle won, the distance is immense, and there stand empires." While the US victory at Midway may have shut the door on the Japanese, it was the eventual American supremacy at Guadalcanal that firmly locked it. No matter which way you look at it, Guadalcanal was no less than a major tuning point in World War Two!
The conflict started started off with a classic case of 'losing' a crucial naval battle (the Battle of Savo Island, August 1942), but at the same time winning a decisive strategic victory by protecting the vital invasion transports lying off Guadalcanal and Tulagi. Overall there were seven major fleet battles (between the USN and the IJN) in less than four months that made up the greater naval campaign for Guadalcanal. In chronological order they were; The Battle of Savo Island, The Battle of the Eastern Solomon's, The Battle of Cape Esperance, the Battle of Santa Cruz, The First (naval) Battle of Guadalcanal, The Second (naval) Battle of Guadalcanal and the Battle of Tassafaronga. Overall these battles contributed to an incredible loss of life and ships on both sides!
On the night of 12th/13th November 1942, (in what was to become known as the First Battle of Guadalcanal) the USS Atlanta was heading a cruiser column behind a van of destroyers patrolling off Guadalcanal over what was soon to become known as 'Iron Bottom Sound'. At about 2am the Atlanta fired what is believed to have been the very first shots at the advancing Japanese column. Under the command of Vice Admiral Hiroake Abe aboard the battleship Hiei, the column had just made an high speed run towards Guadalcanal from an earlier fleet rendezvous off the northern Shortland Islands near Bouganville. The USS Atlanta was also the flagship of Rear Admiral Norman Scott, and as the two antagonists met she was caught in the glare of Japanese searchlights, to which she promptly replied with a salvo of five inch shells from her main guns. This was immediately returned by a withering hail of fire from Japanese gunners.
The Atlanta's bridge was decimated by one or more salvos, killing Rear Admiral Scott and many of his officers. Then a spread of the fearsome Japanese "Long Lance" torpedoes found there mark as 'the Lucky A's' luck finally ran out! With her engine rooms struck by at least one of these deadly torpedoes, her 6000 ton hull heaved in a mortal explosion. She then stumbled into the USS San Francisco's (another American cruiser) line of fire and hits from San Francisco's eight inch armor piecing projectiles just added to the carnage aboard the Atlanta (friendly fire proved not so friendly after all). The Atlanta was now a doomed ship. It had taken only ten short minutes of action for her engines to be dead, her hull holed by a Long Lance torpedo, her superstructure shattered by as many as fifty medium caliber hits and seven of her eight main five inch gun turrets put out of action. But she still had some fight left in her and later that day she managed to fend off an attack by a marauding Japanese 'Betty' bomber. When it was obvious that she could not be saved and with the expected return of the Japanese that night she was scuttled where she stood between Lunga Point and Point Cruz, Guadalcanal. It was Friday the 13th, November, 1942.
Fifty three years and seventeen days later, on 30th November 1995, against the advice of some "experts" who said it was 'too dangerous' and 'not possible' given the conditions (poor visibility and strong tidal currents) two technical trained open circuit scuba divers dived her for the very first time. The dive team consisted of two lead divers, Terrence Tysall from the USA (co-owner of the Orlando Dive Center, IANTD IT, and Director of the Cambrian Foundation) and the author, with Miria Denlay as shallow support diver, John Carr (Island Dive Services) as deep support diver and Lyndon Tohe (Island Dive Services) as surface support personnel. The good ship RV Venus was supplied by David Sinnamon who was absent at the time.
We used a trimix breathing mixture consisting of 11% oxygen, 54% helium, balance nitrogen (11%O2, 54%He, 35%N2) and at a depth of 110msw/360fsw (with an Equivalent Air Depth of 43msw/140fsw and a PPO2 of 1.32ATA ) placed a plaque and three flags belonging to the Solomon Islands, the USA and Australia, in honour of the heroes that died that tragic night. Ours were the first living hands to have touched this sleeping giant, lying in 120msw/400fsw since that fateful day in '42.
Conditions on the day of the dive were perfect and a shot line that had been dropped on the wreck the afternoon before was used as a down line. On arrival over the wreck a large manta ray circled the support boat, which was taken as an sign of good will. Glassy conditions, no current and what turned out to be exceptional visibility on the bottom of at least 25m/80ft awaited the divers. Carrying bottom mix in back mounted doubles, the divers also carried a 90cf cylinder of air under one arm, and EAN50 and EAN80 in 55cf cylinders under the other. On the support boat were more back-up cylinders of all the necessary deco gas, that the surface support divers could bring down if necessary (redundancy, redundancy), and surface supplied oxygen was available if needed at 6msw/20ft. A complete In-water recompression kit consisting of an AGA full face mask, dual umbilical hoses with non return valves capable of supplying both 02 and air to the AGA, a knotted and measured (every foot) ten metre down line connected to a comfortable seat harness for the 'patient' to rest in and the necessary Australian Method in-water recompression tables were also on hand. More than eight cubic metres (280cf) of extra oxygen was on board.
We used a decompression table 'cut' from Pro Planner, with a 15% safety factor added in and still spent an extra 15 minutes on oxygen at 3msw/10ft after we had cleared our actual run time tables. Initially we dropped on air to 55msw/180ft where we switched to bottom mix. Less than four minutes after we had left the surface we were on the wreck. Huge 'jacks' swam along the hull and schools of small fish encircled the hulk. Far from being a dead zone we found this site was teaming with life. After planting the flags and tying off the plaque we made a short excursion and then it was time to leave. (The plaque read: We come to honour and pay our respects, not to disturb and desecrate. We are privileged to visit and touch your grave with the utmost reverence, asking those that follow to preserve this spirit. May we all learn from your struggle. May your battles never be forgotten. This is why we visit.) At 65msw/215fsw we started switching back to air using a back switching technique that minimizes the narcosis jolt, taught to Terrence by the late Sheck Exley. Then by using a 'deep stop procedure' our first deco stop breathing air was at 55msw/180ft. This procedure shortened or decompression time considerably. The rest of the stops were running like clock work and the guardian of the wreck, 'the Atlanta manta', even came back to keep us company on deco. Then at the 12msw/40fsw stop things took a turn for the worse. Unbeknown to us a strong wind (the first in the last two weeks) and resulting waves had sprung up necessitating constantly turning the free drifting support boat into the wind to avoid taking on water. This played havoc with the divers on the deco lines and both Terrence and myself were to later comment that it was the worst deco we had ever had to perform. About two hours after entering the water we surfaced to a choppy sea and the warm smiles of our support crew. It was as if we had stirred the 'Ghosts of Iron Bottom Sound" and this was their way of acknowledging our rather insignificant presence.
Now while most of the doomed naval combatants in the Campaign For Guadalcanal lay way too deep to dive (unless that is you are sporting a one atmosphere Newtsuit), more wrecks still abound off the shores of Guadalcanal itself, Tulagi and elsewhere in the Solomon Islands. All of this kind of diving usually requires going beyond the accepted sport diving limits as many wrecks do not start until about 40msw/130fsw or so and are therefore really only for technical or extended range divers. The focus of our teams visit up until now had been towards diving the USS Atlanta, with a few 'warm up' dives on the deeper wrecks off Guadalcanal. We now spent the next week with Australian underwater photographer Kevin Deacon and his wife Cherie Vasas on the magnificent liveaboard MV Solomon Sea, diving primarily off Tulagi on a recently discovered destroyer, the USS Aaron Ward. She was originally located by Ewan Stevenson, a New Zealander with a keen interest in the Solomon Naval Campaign and first dived in September 1994 by Brian Bailey, so very few people have yet to dive this fighting man of war.
Sunk by aerial attack on 7th April 1943, she now sits upright and almost completely intact with her stern resting in 73msw/240fsw not far from Tulagi, and island some 30kms/20mls across Ironbottom Sound from Guadalcanal. As a matter of interest, just ten days after the Aaron Wards sinking, on 18th April 1943 American P38's operating out of Henderson Field (which was the true prize of the Guadalcanal Campaign and the key to strategic dominance in the Solomon's) with the aid of top secret ultra communications intercepts, shot down a Japanese 'Betty' bomber over Bouganville which was carrying Admiral Isuruko Yamamoto. Another chapter in the war had closed as they had just killed the Imperial Japanese Navy's supreme commander and master architect of the raid on Pearl Harbour!
The USS Aaron Ward is approx. 108m/350ft long and is bristling with armament, four five inch guns, seven 20mm Oerlikons, two dual 40mm Bofors and a brace of five 21" torpedo tubes (with one warhead laying on the deck and another poking out of a tube) while a large search-light sits on a tall pedestal behind the rear funnel. An awesome dive that has to be seen to be believed! She is a deep dive by most standards, as the top of the bridge is at about 50msw/165fsw, her fore-deck is at about 60msw/200fsw, with amidships and towards the stern gradually sloping off to about 67msw/220fsw or so on the deck behind the aft 5" gun. There the stern with its depth charge racks bends radically up at an almost seventy degree angle, from impacting the bottom on sinking. The huge rudder and one high speed propeller are still attached to the bent up stern while the other prop, still connected to its long shaft rests almost buried in the sand below. She is remarkably intact seeing as she was sunk as a result of aerial bombardment (one direct hit, four very near misses that sprung her seems) and a small puncture in the deck is still visibly where the only bomb to actual hit her, penetrated before exploding in the engine room. The rear of her bridge is starting to collapse and her tall mast now lays askew to starboard and where her first funnel was (now lying beside the starboard side of the ship) is a mangled mess. This damage has taken place since her sinking, as mother nature runs its course, as the official action report does not mention any hits near the bridge.
Awesome penetrations abound, with a swim through the officers wardroom at 64msw/210fsw and down a corridor with cabins leading off an unforgettable experience! (No doubt about it, 'cave technique' comes in very handy in there!) In all the wreck dives I have done in the Solomon's, this was the first time I had the feeling of being an intruder. Couches, tables, cupboards, chairs and even a ceiling fan remain in place, but it really felt as if I was violating someone's home. Eerie! On a couple of the deeper exploratory dives we used a light Trimix, mainly to reduce the PO2 but also to reduce the narcosis and 'clarify' the layout in the limited time we had. Bottom times were kept to a maximum of thirty minutes and with the use of accelerated decompression procedures involving gas switches, decompression times where kept to within a manageable time frame.
Sadly enough some locals have taken to looting her and while we were there a departing expat diver was caught by the Solomons authorities trying to smuggle out the aft binnacle stand!
Nearby lies the USS Kanawha, a heavily armed fleet oiler sitting upright in 60msw/200fsw, sunk on the same day as the Aaron Ward. Her stern sports two five inch guns and three AA turrets and is a sight to behold. In one AA turret the spent shell casings of her last ditch effort at survival (she was also sunk by an aerial attack) lie scattered about and amongst them lies the helmet of the gunner! A huge hole blown clean through the hull just forward of the stern (not from a bomb but from an early salvage operation) now allows for a very interesting if somewhat precarious penetration (because of the hanging cables, etc.) and a swim through to the other side of the ship. Dark and at around 55msw/180fsw, this should be only attempted by divers well versed in the art of wreck penetration.
She is a massive ship that one cannot really appreciate in one dive, so many dives can be spent just exploring the deck areas and gun mounts, etc. The main deck lies on an average at about 45msw/150fsw with the bow a little shallower and the stern a touch deeper. The bridge while still somewhat intact shows signs of the massive fire and bomb damage that spelt the end of the Kanawha. While dived more often than the deeper wrecks she is still fantastic dive with much to be seen, although the visibility here can often be down because of where she lies at the mouth of Tulagi Harbour. She is still a 'must see' though.
Off nearby Gavutu and Tanambongo islands, scene of extremely fierce fighting between US Marines and the Japanese, lies at least one if not more Japanese Kawanishi flying boats in about 42msw/140fsw. Inside Tulagi Harbour the New Zealand corvette Moa, instrumental in sinking the Japanese submarine I-1, lies in 42msw/140fsw and was also sunk on the same day as the Aaron Ward. Rarely dived this is still an interesting site but the visibility here is usually poor. Also lying dumped in Tulagi Harbour in about 18msw/60fsw is the huge bow of the battle cruiser Minneapolis, which was almost shot off by a Japanese 'Long Lance' torpedo in the Battle of Tassafaronga on 30th Nov. 1942. (This awesome torpedo was oxygen powered and had the incredible range of 44,000 yards, yes forty four thousand yards or approximately forty seven kilometres, at 36 knots!) The battle off Tassafaronga would be the last time that major naval task forces of opposing sides would meet in the Campaign for Guadalcanal, although the Japanese were not yet prepared to 'throw in the towel' altogether. (As witnessed by more 'Tokyo Express' runs along with other sporadic clashes and air raids through out late 1942 and early 1943). The last starving remnants of what was once thought of by the Japanese to be an invincible army were evacuated from Guadalcanal, with their tail well between their legs, by destroyer pick up on the night of 7/8th February, 1943. Guadalcanal finally 'belonged' to the Americans and their push up the Solomon chain and on to Japan was set to begin.
Now returning to the shores of Guadalcanal island itself we find numerous Japanese transports from Rear Admiral Tanakas' audacious 'Tokyo Express' raids. Off Tassafaronga point lies the huge transport Asumassan Maru, sitting upright with her bow reached at 42msw/140fsw and her stern in 88msw/290fsw. Although she quickly drops away to depths to deep for air diving she is still a must see with huge kingposts towering over the foredeck. The bridge lies between 60msw/200fsw and 70msw/230fsw, and while relatively intact on our last visit in 1994, has now collapsed in on itself considerably. A little further along the same coastline but more to the east lies the Sasaku Maru, on her side and not reached until 58msw/190fsw with her stern in about 83msw/270fsw. While sometimes dived by divers using air she is only reached at the limits of what is considered prudent for air diving and to see her properly one needs to use mixed gas. She then starts to open up her secrets. The remains of a large Japanese submarine, the I-1, lies much further to the west around Cape Esperance and although badly broken up from an early salvage attempt, is in only 30msw/100fsw and still worth a visit.
Other Japanese transports lie beached, one with her bow almost out of the water while the stern rests in 58msw/190fsw, and these are the ones regularly dived by visiting divers. Then to the east of Lunga Point off Red Beach lies an American transport ship, the USS John Penn, on her side in 60msw/200fsw, which is another fantastic dive. A popular dive with locals and visitors alike who like deeper dives, she is reached at about 34msw/110fsw and is often teeming with schools of pelagic fish enjoying the sometimes stiff current. Penetrations abound as her stern is blown completely off leaving easy access to her innards. Much further to the east along the coast lies the armed fleet tug Seminole, also only a fairly recent discovery she is rarely dived, (found and first dived by Ewan Stevenson) but she also is well worth a look.
More ships still await discovery, the most likely contenders being another American destroyer? and the US transport ship George F Elliot, along with possibly another Japanese submarine, all reported to be sunk in deep but diveable depths. We shall see as only time and searching will tell!
Oh, and by the way, the water averages a warm 30º Centigrade/85º Fahrenheit and anywhere from 10m/30ft to 30m/100ft or more of visibility is common on most sites. Smooth surface conditions are encountered much of the year (although there is both a rainy and a windy season) with a topside temperature that is, well, tropical! But don't just take my word for it, go check it out yourself. As you'll never never know if you never never go!
Footnote. The Australian authorities (where the helium is bottled), in all their wisdom have decided to add 3% oxygen (or there about) to all diving grade helium purchased in Australia, "for safety sake". I know I know, but you try telling them that. All it does is make it impossible to get a true reading of the gas content of a mix from an oxygen analyzer and even more difficult when topping up a partly used mix to figure out what the final mix is. (Though it does let you get some 'nice' mixes that pure helium would not give.) We used a mixing program developed and supplied by Egil Österholm of IANTD Finland that took into account this 'Heliox' supply mix, and his program was especially helpful when 'topping up' partly used Trimix's. A special thanks to John Carr of Island Dive Services for his assistance in the USS Atlanta mission. Solomon Airlines were also very helpful whenever possible and is the airline of choice when travelling to the Solomon Islands. Given certain time constraints of team members we had only a short window of opportunity to dive the USS Atlanta. As it was we dived her on the last possible day available in that window. I feel privileged to have had the expertise of Terrence Tysall along on this expedition, the surface support of Island Dive Services and the back up of my wife Miria and Alternate Diving Services. Without all of this support, and other people too numerous to mention, and you know who you are, this mission could not have been completed as successfully as it was. Although this account portrays a smooth running operation, getting there involved a 'little' more work. I humbly thank all concerned.
Note well:. It is considered early days in the Solomons as far as 'technical diving' is concerned so divers who are interested in diving the deeper wrecks should take as much of their own equipment with them as possible and check with their chosen operator well in advance just what is available for rent and if that operator has the ability to access the wrecks you want to dive. Most operators will also require proof of some form of 'technical diver certification' before they will take you to the deeper wrecks that lay outside the spot diving realm. Nitrox is available from Island Dive Services for both diving and decompression use but proof of the various levels of EANx certification is required, depending on its (Nitrox) intended use. And also note well: Wartime wrecks in the Solomon Islands are still US Navy property and are protected under Solomon law as well. Our motto is the well worn "take only photos, leave only bubbles"! We fully support this protection and abhor the looting of wrecks for personal gain. Divers caught looting wrecks or trying to export looted material from the Solomons will find themselves being prosecuted by the relevant authorities. Important note! May I please suggest that the next time a disgruntled diver gets on the internet (as happened earlier this year) with his tale of woe and berating a local Solomon operator, (or any one for that matter) that before believing what is said as "gospel" and taking sides and going on the attack, to check out the "real" story. It never ceases to amaze me that people who would normally be more discerning believe everything that is said on the net! Some folks are obviously a lot more gullible than they appear.
HIGHLY RECOMMENDED READING:
- The Lost Ships of Guadalcanal by Dr. Robert Ballard.
- Derailing the Tokyo Express by Jack Coombe.
- Guadalcanal, the Definitive Account of the Landmark Battle by Richard Frank.
- Disaster In The Pacific by Dennis and Peggy Warner with Sadao Seno.
- The Shame of Savo by Bruce Luxton.
By Bruce V. Voss, M.D.
In the book, Stress and Performance in Diving, Drs. Bachrach and Egstrom list four major predisposing conditions for panic' The state of the diver, coupled with stressors (i.e. cold) lead to impaired functioning. When you add the fourth condition, unforeseen events, you then have a recipe for panic. Within the realm of "state of diver" are listed entities such as physical condition, disease, fatigue, drugs, emotional level, and training.
This article deals with the singular issue of drugs and the diver. Drugs can be defined as "...any substance, synthetic or extracted from plant or animal tissue ... which is used as a mendicant to prevent or cure disease (Butterworth Medical Dictionary)"'. A handy schema to use in referring to drugs is to consider them either prescription or non-prescription medications. The latter can be further divided into illicit or legal medications. I would venture to say that most physical conditions that are being treated by a physician are managed with prescription medications versus non-prescription. The former include those medications for chronic condition, i.e. high blood pressure, heart rhythm problems, respiratory problems such as asthma, chronic obstructive pulmonary disease, bronchitis, etc. The non-prescription medications include the legal (or non-controlled) meds, i.e. alcohol, sinus medications, car/sea sickness pills, headache prescriptions, pain pills, etc. In the illicit category would be the hallucinogens, stimulants like cocaine and amphetamines, euphorics like marijuana, etc., which stimulate the nervous system.
An important distinction needs to be made here. That is, that the autonomic nervous system or the part of the nervous system that responds automatically to the environment (internal or external) can be subdivided into two components. The sympathetic nervous system is the "flight or fight" system and is opposed by the parasympathetic system. These two control body functions and are involuntary and don't require conscious input. The sympathetic nervous system involves increases in sweating, heart rate, blood sugar, and temperature in response to stimuli. The parasympathetic nervous system acts in the opposite direction and opposes a sympathetic nervous system input. Although one exception is the increase in gastrointestinal secretion in response to parasympathetic input. Activation of the sympathetic system is by way of epinephrine (adrenaline) and norepinephrine (noradrenaline). Drugs that activate the sympathetic system can do so because they are chemically similar to epinephrine/norepinephrine, i.e. ephedrine, pseudoephedrine, phenylephrine, phenylpropanolamine, or they can cause a release of those two mediators, i.e. cocaine, amphetamines, etc. Another mechanism for activation would be to give a drug that blocks the parasympathetic system (i.e. anticholinergic agent) and so have unopposed sympathetic activity (adrenergic). In essence, the balance between parasympathetic and sympathetic stimulation dictates the physiologic response that the patient shows, i.e. sympathetic or parasympathetic response.
In terms of legitimate, prescription medications used by physicians, an anatomic schema might serve us well. To start with, many people take meds to control mood, to enhance their sense of well being, and to enhance some personal experience, etc. While the schizophrenics and manic-depressives probably aren't highly represented in the technical diving community, I would guess that there are some divers out there who do take their daily "Valium or Prozac" or even amphetamine. (Remember the hyperactive child in your neighborhood? Well he was diagnosed as having "attention deficit disorder and has in fact grown up and is being treated with amphetamines.) Beyond the obvious problems of diving at depth and being on meds that alter mood and/or perception, the real unknown is the effect of depth on the medications' physiological effect. In the case of drugs known as psychotropics, one medication that has been used at depth (in the hyperbaric chamber) is Diazepam, i.e. Valium. That also is in a controlled environment and one that lends itself to intervention easier than at say 200 fsw (60 msw) in open water. In fact, the late Jefferson Davis, M.D. in his "Medical Examination of Sports Scuba Divers" categorically excluded candidates for diving if they are on psychotropics or the nonprescription legitimate drugs that are used for mood altering or enhancing effects, alcohol is probably at the top of the list. We are all aware that alcohol intoxicates and decreases performance, but there are some other effects that this "drug" has associated with it. First, it dilates or opens up the blood vessels, which allows more blood to be brought to the skin and, therefore, more heat lost. It is associated with increased risk of vomiting and, therefore, aspiration (or inhaling stomach acid, contents, etc., into the lungs.) It, like tea and coffee, is a diuretic, which means it causes you to urinate more, which means your circulating blood volume decreases (less free water is available to dilute the blood volume). This predisposes divers to decompression sickness (DCS). Also, it will act in a manner that is more than additive (that is, 1 + 1 is greater than 2) when you couple it with nitrogen narcosis. Not to be excluded, caffeine (that is, coffee, tea and colas) has come under attack in the last few years. There is data to show that coffee will raise blood pressure, which, in the right individuals and diving at depth could give an unwanted hypertensive response. Also it can cause ectopy (extra beats) in the heart. This could lead to a fatal dysrrhythmia (malignant and erratic heart beat). While on the topic of caffeine and mood altering drugs, some of us do use caffeine preparations to combat fatigue. Getting "wired" from a caffeine-type agent and then diving, while it may enhance your attentiveness, it will also increase your heart rate, metabolic rate, respiratory rate and oxygen consumption rate, which in, and of itself is a recipe for disaster. The next area of concern is the respiratory tract. While we probably won't see the "Blue Bloaters" and "Pink Puffers" (chronic bronchitis and emphysematous patients respectively); we probably will see the diver who enjoys his/her cigarettes after their dive, or the diver who says he/she gets a little tight in the chest during a certain season or climate change. And what of the diver who has a yearly bout of bronchitis, lays off the cigarettes, and gets antibiotics for 10 days? Does that diver have an increased risk for barotrauma? Many would say yes. But with cyclical changes and a paucity of findings, these individuals will continue to dive. There are a variety of medications that can be prescribed with respect to the respiratory tract. The majority of patients with respiratory meds in all likelihood will probably be using, bronchodialators, i.e. Ventolin, Proventil, or a theophylline mixture, i.e. Theodur. While the drugs themselves don't have a track record of causing problems at depth, the underlying condition that would cause one to use these meds do. If the pulmonary condition is bad enough to require bronchodilators, then few would disagree that the patient shouldn't be diving. Also, some patients with respiratory problems may be using, a prescription antihistamine. Usually these have the side affect of sedation. Needless to say, sedation and diving is a bad combination. There are a class of nonprescription "cold" meds, like the ephedrine or pseudoephedrine (Sudafed, Actifed) based meds that will cause an increase in heart rate, blood pressure, and will make you rather jittery or nervous. These affects come about because the drug is being used systemically, that is, in an oral form that circulates in the whole body. If the diver instead uses a locally applied, i.e. topical, agent like neosynephrine nose drops, the systemic effect will be less. Neosynephrine is an agent that acts as a vaso constrictor. It makes blood vessels, especially in the mucus membranes, shrink in size temporarily. This gives relief from the feeling of "congestion" in the sinuses/nose.
Lumping the gastrointestinal and genito-urinary systems together, there are a few meds that while they are used in these areas, there are effects elsewhere. Patients with spastic colitis or irritable bowel syndrome may be taking anti-cholinergic agents. These slow down the natural "parasympathetic nervous system". The end result can be decreased sweating, light insensitivity, blurring of the vision, dry mouth, etc. Also, the heart rate may increase. The decreased sweating can increase the risk of heat stroke in hot climates, etc. Also, some divers have been taking medications for ulcers, acid reflux or a hiatal hernia. A popular class of agents for these mild maladies is the histamine type two (H-2) blockers or antagonists. Cimetidine (Tagamet) or Ranitidine (Zantac) are in vogue. These may cause sedation/drowsiness or headaches, with Zantac causing less side effects than Tagamet. Some patients may also use a drug called Reglan (metoclopramide) for acid reflux. This drug is capable of producing sedation and "extra pyramidal reactions". In essence, musculo-skeletal reactions like spasms or contractions, etc. For those patients suffering Montezuma's revenge and taking Lomotil, there is also a word of caution. Lomotil is a combination of atropine (an anti-cholinergic) and diphenoxylate, a relative of meperidine (Demerol). Demerol is a narcotic and as such can and does cause sedation and respiratory depression, whose affects could be additive or synergistic when coupled with nitrogen narcosis. As an aside, antibiotics by themselves, seem to be OK, but the havoc they can cause in the GI tract can be unpleasant. First of all, they can cause nausea and vomiting. Also, many of them can cause a "colitis" picture with a resultant diarrhea that can not only be profuse, but can cause an acid base imbalance in the blood. The logical question would be, "Why would anyone with diarrhea want to dive?" Well, after paying a sizable amount of money for a dive trip and equipment, and while being selfmedicated from the local drugstore, it is really a question of not what's probable, but what's possible. And as far as human nature goes, anything is possible. A quick word about nausea and vomiting, since there are a wide variety of agents for nausea, ranging from pills to patches. Most of these meds like Atarax, Antivert, Benadryl, Compazine, Phenergan, Thorazine, and Tigan, can cause sedation and when combined with nitrogen narcosis or DCS, the results may be very unpredictable. Some of these agents have as side-effects neurological ramifications besides just sedation. Those neurological effects can range from muscle spasms and seizures to coma and death. Obviously, a diver exhibiting those effects will be a liability to himself/ herself as well as to others.
Similar to antibiotics are the anti-viral agents. Most of these are injected, but there are a couple that are used in pill form and may be around in the diving population. It is not likely that an HIV positive patient under active anti-viral therapy would be diving, but it is likely that a patient with a history of herpes (genital/oral or shingles) may be. Since as a professor in medical school once said, "...The difference between love and herpes is that herpes is forever." Therefore, a drug that may be used long term in a diving individual is acyclivir (Zovirax). This agent does have a history of causing nausea, vomiting, and headaches. Divers using this agent should be aware of those side effects. Another agent used to decrease the symptoms of a viral complaint, that is, the common cold, is a drug called amantidine (Symetrel). You should know that this agent can also cause nausea, dizziness, and insomnia.
Moving on to the urinary tract, a major class of medications used here are the antispasmotics (the anti-cholinergic class) which, as stated before, can cause a dry mouth, blurred vision, increased heart rate, and sensitivity of the eyes to light. Also, decreased sweating can occur. Some of the agents in this class are Cystospaz, Ditarpan, Luvsin, Urised. Some of these agents if used in excess (or possibly coupled with DCS, nitrogen narcosis, etc.) have the propensity to proceed to a full-blown cholinergic crisis (Hypercholinergic State). That would entail restlessness, irritability, tremors, convulsions, and respiratory failure. There is another class of drugs that are used for stimulation of the male urinary tract, specifically for male sexual dysfunction (objective dysfunction, not just a feeling of inadequacy). This class is an adrenergic antagonist or blocker, specifically alpha '-. Daytohimbin is one of those drugs (yohimbine is the generic name) and it allows unopposed stimulation of the cholinergic system. The patient can exhibit decreased urine output, agitation/ irritability, increased blood pressure/heart rate, tremors, nervousness, headache and dizziness. Obviously, this is not a good thing to have happen while diving. In some patients, the physician may prescribe the drug Benemid (probenecid) to increase blood levels of penicillin and other antibiotics. What has also been found, though, is that this drug may increase the blood levels of lorazepam (a Valium type of drug), oral sulfonylureas (pills used to decrease blood sugar in diabetics) and the anti-inflammatory drugs like Tylenol, Ibuprofen (Motrin, Advil), etc.
The next area of medical management that is disproportionately represented in most people, and probably in more than a few divers, is the cardiovascular system. The intervention in this area runs the gamut from management of high blood pressure and heart rate control, to control of angina (chest pain). There is a multitude of agents used in cardiovascular conditions, but the most popular classes are the beta and calcium channel Mockers, alpha Mockers, ACE (Angiotension Converting Enzyme) inhibitors, diuretics, anti arrhythmics, vasodilators and vasopressors. Taken as a whole, any patient taking these medications should think seriously about not diving while under the influence of them. Their collective side effects can range from low blood pressure and fast heart rate to bronchoconstriction (narrowing of the breathing passages) and severe, even fatal, aberrant heart rhythms. We also must keep in mind that we, as individuals, use medications and drugs that are not only not prescribed, but also in some cases outlawed by current federal regulations. Marijuana, cocaine, and alcohol are popular agents that affect the cardiovascular system as well as other systems. While used primarily for their euphoric and stimulating properties, these three alone can be unpredictable but in combination can be lethal. If you then add a hyperbaric situation, you have gone from an unpredictable situation to a potentially lethal combination of events that also threatens the other divers present. In an interesting recent medical report, it was found that while both alcohol and cocaine individually can cause cardiac damage, together their effect was more than 1) plus I greater than 2) additive'. Needless to say, with the complexity of the individual drugs and their interactions with each other, any diver undertaking their use while diving would be well served in seeking professional advice. The potential scenario of the respective drug and its unknown contribution to a hyperbaric scenario, cannot be underestimated nor predicted accurately.
References:
By Bruce V. Voss, M.D.
Another area of medical intervention that seems to be popular is the muscular/skeletal area. It seems that the drug companies aren't satisfied with battling each other over physician recognition and keeping that conflict in the office/hospital realm. Now they have resorted to recruiting the lay public in their fight. So, what you may see in the local daily newspapers in this country is company "X" advertising their prescription drugs in favor of their competitor's drug. Is this healthy? I doubt that having- the patient act as an agent of the company and be-inning to doctor "shop" until they find an M.D. who will give them the drug they think they want is healthy. It seems that a lot of money is spent on curing the muscle aches and pains we all are subject to. Unfortunately for the drug companies, the OTC (over-the-counter, i.e., non-prescription) crowd has empowered competitors to mass produce the popular non-steroidal anti-inflammatory drugs (NSAIDS) lbuprofen and all of its pharmacological look a-likes. When you add to the NSAIDS the other available analgesics, you end up with quite a laundry list of drugs. These medications are given for general aches and pains, spasms, strains, sprains and almost any other muscular malady. Contained in the list are the aspirin and acetaminophen (Tylenol) type of agents, with and without codeine, the whole series of NSAIDS, i.e. ibuprofen, naproxen, ketrolac, etc., the narcotics (synthetic) and narcotics in combination with salicylates (aspirin), the non narcotic and anxiolytic (anxiety relief) agents, i.e. Darvocet, Fiorinal (barbiturate-based), and Parafon Forte. To this list, you also need to add muscle relaxants like Robaxin, Flexoril, and Soma. Not uncommonly, some patients will also receive a benzodiazepine (anxiolytic), like Valium, to help with their muscle spasms and anxiety. Not to be neglected, a very potent class of medications called steroids is sometimes prescribed. These can be in combination with many of the above listed agents or they can be used alone. Again, because this list is so extensive and the combinations so varied, almost any type of side effect and reaction can be found. You need to check with your physician or pharmacist about the wisdom of diving with the above mentioned drugs. In particular, the class of drugs called steroids can have some nasty side effects, to include fluid retention, electrolyte loss, and avascular necrosis of the femoral head (cellular death of the head of the upper leg where it joins the hip socket). Some studies showed rates of dysparic osteonecrosis (avascular necrosis) from 2.7% to 80%. The higher rates were with saturation divers, deep helium (greater than 500 fsw/150 msw) dives, and divers with numerous DCS events. Steroids can also lead to increased susceptibility to hyperbaric oxygen toxicity and infections.
Another large area of medical management that may impact on divers are the endocrine/metabolic systems. This runs the gamut from diabetes to thyroid dysfunction. This can also encompass fertility agents, cholesterol lowering agents, hormonal manipulation, i.e. antibiotic steroids, oral contraceptives, and thyroid preparations. Out of this laundry list of conditions, nothing has probably prompted more debate and research than diabetes. The issue really is should a person who has to artificially control his/her blood sugar be diving? In that vein, should that person be sport diving or partaking in technical diving if not fully aware of the ramifications of low blood sugar (hypoglycemia) or high sugar (hyperglycemia). The stress response and its effect on blood sugar and the implications for the diver's partners/friends is paramount. To start with, DAN (Divers Alert Network) recently launched a research project to delve into the problem of diabetes mellitus (DM) and the sport diver'. In the Alert Diver magazine (DAN), the Undersea and Hyperbaric Medicine Society (UHMS) is quoted as being supportive of divers with diabetes mellitus. The exceptions they make are: (1) no history of severe hypoglycemia in the last 12 months (loss of consciousness, seizures or requiring assistance of others), (2) patients with advanced secondary complications (i.e., disease of the eyes, nervous system or heart disease), (3) patients who are unaware of hypoglycemia (lacking stress symptoms), and (4) patients who do not have adequate control of their diabetes or do not understand the relationship between exercise and diabetes. Clearly, there are divers who dive regularly with diabetes and have enjoyable dives. Should they be diving deep, that is greater than I 10- 1 30 fsw/33-39 msw? Since we as individuals still have the free-will to risk our lives pursuing our dreams and adventures, there will undoubtedly be someone who says he/she can dive with diabetes. Well, I don't necessarily disagree, but does that same diver also have the right to put you or I at risk? That is a difficult question to answer. I would say that if I knew my diving buddy had diabetes and I chose to dive with him, then I also assume the risks and can't complain. Anyway, if you want to participate in the DAN study or have questions about diving and diabetes, call DAN at Duke University (919-684-2948). With respect to the cholesterol lowering drugs, one side effect they may have is neurologic. This can present itself as dizziness, fatigue, even numbness in the extremities can occur. This is not unlike thyroid dysfunction and, in fact, with thyroid replacement, if the patient receives too much, he/she can become hypermetabolic. That is not the way to have an enjoyable dive at 200 fsw/60 msw. But admittedly in the past, some physicians have prescribed thyroid replacement hormone to increase the metabolic rate and help the patients to lose weight. So if the hormone isn't being used for actual hormonal replacement, it might be advisable to dive when not under the influence or effects of the exogenous (supplemental) hormone. If it is for replacement, then the prudent diver would check with his/her physician about the actual drug levels (which should be done on a regular basis) and then the scenario of superimposing a hyperbaric situation on top of that. It has been shown that oxygen toxicity is enhanced with increased thyroid hormone and when that causes the patient to be hypermetabolic, this scenario could spell disaster. In terms of oral contraceptives, these should cause some concern since, theoretically at least, they can cause an increase in blood coagulation (clotting) in the veins and if combined with smoking, they greatly enhance the risk of heart attack in women who are over 35 years of age. But as far as the hypercoagulation ability goes, its effect would also manifest as an increased risk of decompression sickness. Though this has not yet been supported by well designed clinical trials.
The above listed agents and drugs should not be construed as an all inclusive or all encompassing list'. There are some that are not mentioned for obvious reasons, i.e. anti seizure medications. Some aren't listed also because of the data being so minuscule or the disease itself being a contraindication to diving, i.e. ophthalmologic agents for glaucoma, etc. Also, areas I haven't touched on at all are the medications/drugs that you can buy at the health food store. Massive doses of certain vitamins, i.e. vitamin A, can mimic some pathologic states and large doses of certain amino acids have in the past caused syndromes of muscle aches and sleep disorders, as well as severe metabolic disorders and acid base imbalances. So, health food supplements can cause a lot of problems if taken in an unwise/uninformed fashion. In essence, the bottom line rule is that you as the diver should understand the effects of the medications you are taking and have an appreciation for those effects at depth as well as the risk you not only assume but also impose on others. Therefore, you are obligated to be informed about the drugs you are taking and that can be done through your prescribing physician or a knowledgeable pharmacist. Remember, God protects fools and drunks, and once I've been informed, I am no longer a fool, that is, devoid of knowledge.
References - (For both Part 1and Part 2)
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