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1775 - ansPriestly "discovers" oxygen Bert - ansFather of pressure physiology 1906 - ansHaldane - staged decompression tables 1937 - ansBenke - O2 tolerance limits 1932 - ansBehnke - lethal air embolism from shallow ascent 1960 - ansCompression therapy for sever altitude dives 1967 - ansUMS 1986 - ansUHMS 1889 - ansCompression therapy for caisson workers 1841 - ansM Triger 1st caisson used in France for coal mining M Triger - ansDescribes pain /paralysis and relief from recompression Brooklyn bridge - ans110 dcs/2 fatal 1878 - ansP Bert - caissons disease Bubble theory of dcs Oxygen toxicity Hudson river - ans1st recompression chamber in USA 1690 - ans1st diving bell E Hadley 1825 - ansW James - 1st SCUBA 1662 - ansN Henshaw - domicilum P Bert - ansHigh altitude hypoxia dcs Oxygen toxicity 1928 - ansH Timkin - hyperbaric hotel Churchill-Davidson - ansAcrylic port for radiation therapy Boyle's Law - ansPV=PV Charles' Law - ansV/T=V/T Gay-Lussac's Law - ansP/T=P/T General Gas Law - ansPV/T=PV/T Henry's Law - ansas pressure increases, the gas in liquids increases, and as temperature increases, the gas in liquids decreases 1960 - ansBoerema - life without blood removed blood cells from pigs Rapture of the Deep - ansNitrogen Narcosis Nitrogen Narcosis - ansBreathing in an increases partial pressure of nitrogen above 2000mmHg Central nervous system oxygen toxicity - ansSeizure caused by breathing an increased partial pressure of oxygen Dalton's Law - ansin a mixture of non-reacting gasses, the total pressure exerted is equal to the sum of the partial pressures of the individual gases. Pascal's Law - anspressure exerted anywhere in a confined incompressible fluid is transmitted equally in all directions throughout the fluid such that the pressure variations (initial differences) remain the same Graham's Law - ansthe rate of effusion or of diffusion of a gas is inversely proportional to the square root of its molecular weight. Inspired pO2 - ans=pTotal x fiO Alveolar pO2 - ans[(pTotal-pH2O) x fiO2]-pCO
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pH2O - ans47mmHg (water vapor produced in lung) pCO2 - ans50mmHg produced by lung breathing air 40mmHg produced by lung breathing oxygen barotrauma - anstissue damage resulting from a pressure inequality between the environment and a gas-filled space within the body otic barotrauma - ansreddened tympanic membrane fluid in middle ear space otosclerosis - ansimmobilization of stapes bone behind tympanic membrane optic barotrauma - ansmask squeeze most common barotrauma in hyperbarics - ansmiddle ear barotrauma methods for equalizing middle ear - anstoynbee frenzel swallowing valsalva toynbee maneuver - anspinching nostrils shut while swallowing frenzel maneuver - anspinch nostrils shut and raise back 1/3 of tongue and cause the adams apple to elevate (throat piston) middle ear barotrauma - anspain in the ear during pressure change fullness or difficulty hearing tympanic membrane rupture eustachian tube - ansanatomical apparatus through which middle ear equalizes complaint of ear pain during pressurization - ansstop compressing the chamber cleft palate - ans(unable to equalize) cannot form a seal in nasopharynx endotracheal tube - ansunable to equalize) cannot close glottis agressisve valsalva - ansround window rupture round window rupture - ansperilymph fistula inner ear barotrauma alternobaric vertigo - ansunable to equalize one ear pressure differences as low as 20mmHg transient dizziness, disorientation,nausea, vomiting myringotomy - anssmall surgical opening in tympanic membrane reverse block - anspain on ascent, often from decongestant wearing off ear sinus or tooth sinus barotrauma - ansfrontal and maxillary most common can mask as tooth pain sea level to 10 FSW - ansmost likely point of barotauma borodontalgia - anstooth barotrauma tooth squeeze pulmonary barotrauma - ansbreath holding on ascent - 4FSW most dangerous form pneumothorax arterial gas embolism hyperbarics scuba diving trauma
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Mechanical compression of bubbles during HBO - ansforce nitrogen back into solution diminishes blood flow blockage heavy exercise while at increased pressure - ansincreases DCS risk 12 hours 1 minute (more than 12 hours) - ansRNT to reach zero dives not repetitive hyperbaric oxygen - ans100% oxygen intermittently
1ATA normal arterial pO2 - ans80-100mmHg red blood cells - anscarry O2 and CO Stage 1: Inflammatory Stage [Substrate, lag, or exudates phase] - ans-from injury to 4-6 days
- vasoconstriction to stop bleeding then vasiodilation to allow clean-up crew cells into the area
Stage 2: Fibroplasia [Reparative, migratory, and prolifearative phase] - ans-from day 3-5 to day 14- 28
- restores mechanical integrity to the wound Stage 3: Maturation Phase [Remodeling phase] - ans-from day 25 to 6 months to 2 years
- overlaps with stage 2 around day 15
- prolonged period of metabolic activity where randomly oriented collagen fibers become more organized Primary Intention Healing - ans-wound edges held together mechanically
- 10 - 14 days Secondary Intention Healing - ans-wound closes by natural biologic process Delayed Primary / Tertiary Closure - ans-allowed to heal on it's own for a period then closed mechanically Healed wounds will gain what percent of tensile strength - ans80% compared with non- injured skin Split Thickness Skin Graft (STSG) - ansUsually viable in 3-5 days. May be meshed for drainage. Full Thickness Skin Graft (FTSG) - ansUsually viable in 5-7 days, harvested from hypothenar eminence, medial arm, or groin. You should avoid direct modalities over skin grafts for how many days - ans7-10 days. You can generally expose to water at 4-5 days. Skin Flaps - ansUsed for wounds with limited blood supply, or gliding structures are exposed. Local Flap - random pedicle flap - ansOriginate from tissue adjacent to the wound and are vascularized from the subdermal layer. eg z-plasty, Moberg Advancement Flap Pedicle Flap - ansRequire anastamosis to blood supply, has sensory organs attached. Will be removed later. Immobilize for 3 weeks. Free Tissue Transfer Flap - ansRequires anastomosis to blood supply. Can begin early mobilization. Random Flap receives blood supply from... - ans...subdermal or subcutaneous supply Axial Flap receives blood supply... - ans...from a single blood vessel. A scab presents... - ans...a mechanical barrier to epitheliazation, but also a biologic dressing for superficial wounds.
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According the the US Institute of Surgical Research, what level of contamination constitutes sepsis? - ansBacterial growth exceeding 10 to the 5th organisms per gram of tissue. Marion Laboratories described the three color concept which includes. - ansRed (beefy red granulation tissue, uninfected, definite borders), Yellow (creamy ivory to canary yellow with draining, purulent exudates that are either thick or thin), and Black (covered by thick, black necrotic tissue or eschar) Enzymatic Dressings - ansCollagenase, Santyl, Elase, Accuzyme Hydrocolloid Dressings - ansBiofilm, Comfeel, Duoderm, Granuflex Semi-permeable hydrogel dressings - ansNuGel, Vigilon, Elasto-Gel Geliperm, Intrasite Semi-permeable foam dressings - ansAllevyn, Nu-derm, Flexzan Semi-permeable film dressing - ansOpsite, Polyskin, Tegaderm Permeable to bacteria - ansSemi-permeable hydrogel dressings (NuGel, Vigilon, Elasto-Gel Geliperm, Intrasite The safety of a patient receiving HBO therapy is the responsibility of: a. The physician b. The registered nurse c. The technician. d. All of the above - ansd. All of the above Even though our patients breathe oxygen while undergoing an HBO treatment, attendants in a multiplace chamber breathe air. Which of the following is a risk for the attendant? a. Decompression sickness. b. barotrauma c. Nitrogen narcosis. d. All of the above - ansd. All of the above. You are involved in treating a patient for an air embolism in your multiplace chamber. The patient is on a ventilator. In the first few minutes of treatment, the patient is getting worse. The physician locks into the chamber to assess the patient and orders an excursion to 6 ATA. As the chamber descends beyond 140 FSW, it is noted that the patient does not appear to be adequately ventilated. What is the appropriate way to address the problem? a. Send another person into the chamber to manage the patients airway. b. The physician inside the chamber should decide how to adjust the ventilator settings. c. The respiratory therapist outside the chamber determines the proper ventilator setting. - ansc. Due to Nitrogen narcosis, someone outside the chamber should be making the medical decisions at greater than 3 ATA. You are the inside attendant taking care of a 54 year old female with a history of osteomylitis of the tibia who is receiving HBO treatments. She has just been to surgery for incision and debridement and comes to you immediately post-op. She has two IV's infusing into her central line. As the treatment begins and pressure starts to build in the chamber, you notice that the air/fluid level of the drip chamber of both IV's appears to be filling with fluid (the air space is becoming smaller). You know that this is: a. Unusual and ask the chamber operator to stop compressing the chamber. b. Unusual and ask the patient if she feels okay. c. Normal. d. Normal but notify the physician for further instructions - ansc. Normal, Boyles law.
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d. Subcutaneous injection. - ansa. IV (intravenous) and PO (by mouth) routes are the most reliable methods for delivery of medications. The treatment does not cause any unusual side effects for either of these routes. IM (intramuscular), dermal patches, and subcutaneous routes may be affected we know that the treatment causes vasoconstriction and this may affect the way medicine is absorbed and then distributed. Which of the following drugs produced a very high (87%) mortality rate in rats when combined with HBO? a. Doxorubicin. (Adriamycin) b. Bleomycin.. c. Disulfiram. (Antabuse) d. Cis-Platinum. - ansa. Doxorubicin (Adriamycin). This side effect is presumed to be due to cardiac toxicity. As far as I know, there aren't any human studies to support this, but it would not be smart to treat a patient in HBO who is taking doxorubicin. (Think ricin kills, doxoRubICIN) Administration of which of the following drugs used to be considered a relative contraindication to HBO therapy because it was thought to cause pulmonary fibrosis? a. Doxorubicin. (Adriamycin) b. Bleomycin c. Disulfiram. (Antabuse) d. Cis-Platinum. - ansb. Bleomycin. It was previously surmised that any history of receiving bleomycin would put a patient at risk for pulmonary oxygen toxicity if they were exposed to oxygen-enriched breathing gas. Which of the following drugs was found in animal research to block the production of superoxide dismutase, which is the body's major protection against central nervous system oxygen toxicity? a. Doxorubician (Adriamycin) b. Bleomycin c. Disulfiram (Antabuse) d. Cis-Platinum. - ansc. Disulfiram (Antabuse) is given to humans to deter the drinking of alcohol. Can treat with HBO, this is not a containdication. Which of the following drugs was found to actually decrease wound breaking strength in mice? a. Doxorubicin. (Adriamycin) b. Bleomycin c. Disulfiram. (Antabuse) d. Cis-Platinum. - ansd. Cis-Platinum. no human studies, but not wise to give to patients in HBO If you had a patient that was cuurently taking Doxorubicin (Adriamycin), what precautionary measures should you take before initiating HBO therapy? a. Decrease the dose of doxorubicin. b. Decrease the total pressure in the chamber. c. Wait 3 days for the drug to clear the body. d. Any history of taking this drug makes it difficult to treat this patient. - ansc. Wait 3 days for the drug to clear the body.
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If you had a patient that was currently taking Disulfiram (Antabuse), what precautionary measures should you take before initiating HBO therapy? a. Administer steroids to reduce the inflammatory response. b. No special precautionary measures are required. c. Wait 14 days for the drug to clear the body. d. Any history of taking this drug makes it difficult to treat this patient. - ansb. No special precautions. No ill effects from combining HBO and Antabuse. If you had a patient that was currently taking cis-platinum, what precautionary measures should you take before initiating HBO therapy? a. Decrease the dose of cis-platinum. b. It would depend on the reason the patient needed HBO. c. Wait 2-3 days for the drug to clear the body. d. Any history of taking this drug makes it difficult to treat this patient. - ansb. Depends on reason for treatment. CO poisoning or AGE no adjustment needed. If a wound was involved, wound breaking strength should be considered in decision to treat. The use of mafenide acetate (Sulfamylon) is not recommended while a patient is receiving HBO. The alternative is to: a. Use triple antibiotic ointment (Neosporin) instead. b. Use silver nitrate instead. c. Use silver sulfadiazine (Silvadene) instead. d. Use any moisturizing lotion instead. - ansc. Silver sulfadiazine (Silvadene) is a good substitute for mafenide acetate (Sulfamylon) in the burn patient who is receiving HBO. The other three have have petroleum in the ointment and should not be used in hyperbaric oxygen environment. The one condition considered to be absolute contraindication to receiving HBO therapy is: a. Pregnancy. b. An implanted pacemaker. c. An untreated pneumothorax - ansc. Untreated pneumothorax. Pregnancy is usually a reason to keep someone out of the chamber. If the pregnant female is exposed to CO poisoning, it is a reason to treat. The following are considered relative contraindications to receiving HBO therapy EXCEPT: a. Upper respiratory infection. b. Emphysema with CO2 retention. c. High fever d. Breast implants. - ansd. Breast implants. The patient most at risk for a spontaneous pneumothorax is: a. Fat, short, and female. b. Lean, tall, and female. c. Fat, short, and male. d. Lean, tall and male. - ansd. Highest risk group History of a spontaneous pneumothorax is an absolute contraindication to scuba diving and receiving HBO therapy. TRUE or FALSE - ansFalse. It is a contraindication for diving but not HBO therapy
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assistance with the ambu bag and supplemental oxygen. In the middle of a series of chest compression, you hear a cracking noise and feel what you think is a rib breaking. What is your next action? a. Keep going with the chest compressions. b. Stop doing chest compression because you might puncture a lung. c. Continue the chest compressions but don't push as hard. d. Let someone else do the compressions. - ansa. Keep going with the chest compressions. What is the risk of doing a forceful Valsalva maneuver? a. Round or oval window blowout. b. Sinus squeeze. c. Reverse block. d. Otitis media. - ansa. Round window or oval window blow out. Extremely rare. What are the sign/symptoms of a round or oval window blowout? a. Bloody discharge from the ear, severe pain, vertigo. b. Severe pain in the forehead, deafness, fecal incontinence. c. Deafness in the affected ear, tinnitus, vertigo. d. A sensation of water in the ear, unusual sounds, severe headache. - ansc. Deafness in the affected ear, tinnitus,vertigo. What is the most common barotrauma in patients undergoing HBO treatments? a. Inner ear barotrauma. b. Pulmonary barotrauma. c. Sinus barotrauma. d. Middle ear barotrauma. - ansd. Middle ear barotrauma An ocular side effect of receiving HBO treatments is: a. A worsening of myopia. b. An improvement of presbyopia. c. The formation of cataracts. d. Both "a" and "b" - ansd. Both "a" and "b", Myopia is difficulty in focusing on distant objects. Presbyopia is an age related difficulty focusing on close objects. Cataracts were commonly believed to be worsened by HBO but not Caused by HBO. However that has been refuted. Risk factors that increase the likelihood of an oxygen toxicity seizure are all of the following EXCEPT: a. High fevers. b. Alpha tocopheral. c. Steroids. d. History of seizure activity. - ansb. Alpha tocopheral. Another name is vitamin E. It appears to provide a protective mechanism against pulmonary oxygen toxicity and to raise the seizure threshold. All of the following will decrease the likelihood of oxygen toxicity seizure EXCEPT: a. Phenobarbital b. Diazepam (Valium) c. Hypothermia. d. Levothyroxine (Synthroid) - ansd. Levothyroxine (Synthroid) An oxygen toxicity seizure is easily confused with:
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a. Pulmonary toxicity. b. A heart attack. c. A hypoglycemic reaction d. Dancing the funky chicken - ansc. A hypoglycemic reaction. Your patient is a 63 year old man with a medical history of atherosclerosis, diabetes, gout, rheumatoid arthritis, hypercholesterolemia, and hypertension. He is being treated in the multiplace HBO chamber on a daily basis for aplantar foot wound that he has had for more than 8 months. He has completed 15 treatments. Today, he is running late for his treatment because his dog was sick this morning and had to be taken to the vet. You attempt to speak to him and he is not responsive. You touch his shoulder and he starts to shake uncontrollably. What is the first action you take? a. Notify the chamber operator to reduce the chamber pressure. b. Notify the doctor that you have a problem. c. Remove the patient's oxygen delivery system. d. Start CPR. - ansc. This is classic seizure scenario. Regardless of why he is seizing, remove his oxygen supply. To determine if it is hypoglycemic reaction you need to take his blood suger. Of course you notify the HBO physician. In the previous scenario, which answer would you avoid? a. Notify the chamber operator to reduce the chamber pressure. b. Notify the doctor that you have a problem. c. Remove the patients oxygen delivery system. d. Start CPR. - ansa. Notify the chamber operator to reduce the chamber pressure. under no circumstances do you reduce pressure while the patient is actively seizing. Reducing the pressure while the patient is not breathing could cause a pulmonary barotrauma (pneumothorax). For the patient who has diabetes and takes medications to control blood sugar, it is imperative that. a. We get a hemoglobin A1C before each day's treatment. b. We instruct on foot care. c. We get a diabetes consult to help the patient manage their diet/blood sugar. d. We monitor blood glucose before each day's treatment. - ansd. We monitor blood glucose before each day's treatment. answer "a", you only check Hemoglobin A1C every 3 months. On average, a person taking anti-hyperglycemics will drop their blood sugar. a. 20 mg/dl per treatment. b. 50 mg/dl per treatment. c. 75 mg/dl per treatment. d. 100 mg/dl per treatment - ansb. 50 mg/dl per treatment. This is only an average. Each patient will be different. and each patient will vary day to day. The treatment for hypoglycemic reaction is. a. Hold all diabetes meds for 24 hours. b. Feed the patient if he/she is conscious. c. Teach the patient and family how to administer insulin properly. d. Withhold all food until blood glucose is stable. - ansb. Feed the patient if he/she is conscious. Feed them a simple carbohydrate, like juice or some quick acting suger/gel
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You tried to treat a new patient yesterday but were unable to get him to treatment pressure due to difficulty equalizing his left ear. He was sent to an ear, nose, and throat specialist for evaluation and placement of pressure equalization tubes. He comes back to you today with tubes in both tympanic membranes (TM's). Can you treat him today? a. Yes, there is no need to wait. b. Yes, but I must complete his first compression very, very slowly to allow the tubes to "set" properly. c. No, it is imperative to wait 2 days. - ansa. Yes, he is good to go. However watch for problems - the tubes could be blocked with blood or fluid You are preparing to treat a patient with CO poisoning who is currently in the ER. She was found unconscious at the scene. She has been showing signs of awakening but she cannot communicate with you at this time. Her treatment needs to be started. What would be the quickest method of getting her to pressure without rupturing her tympanic membranes? a. Consult an ENT to put in pressure equalization tubes. b. Have a qualified ER physician perform a myringotomy. c. Just pressurize quickly and the TM's won't rupture. d. None of the above. - ansb. A myringotomy is fast and will solve the problem. ENT is OK, just takes time. A myringotomy is : a. The removal of the Tympanic membrane, commonly performed by ENT's. b. The insertion of pressure equalization tubes for the purpose of ventilating the middle ear space. c. A small incision made in the tympanic membrane that allows the pressure in the middle ear space to equalize. - ansc. A myringotomy is nothing but a small slit made with a scalpel in the tympanic membrane. You have just received a call from the ER that they will be sending a CO poisoning patient to you for treatment. The patient is a 43 year-old male who was found unconscious in a car with the motor running in his garage. He is still unconscious, intubated and on a ventilator. His pulse oximeter is showing 99%. Vital signs are stable. He has a foley catheter with 100cc of clear yellow urine. IV fluid is NS (normal saline) at 50 cc/hour to the left AC fossa ( the front part of the elbow commonly used for IV insertion) COHgb has been drawn but the results are not back yet other labs are all WNL's (Within normal limits). EKG shows normal sinus rhythm. Since the ER docs are familiar with your department. they have done a myringotomy. What procedure should you perform before you can start compressing this patient in the HBO chamber? a. Empty the foley bag. b. Change the IV fluid to D5W ( IV flid of 5% dextrose and water) c. - ansd. It is customary to remove the air from the ET cuff and replace it with saline due to the effects of Boyle' s lam on the cuff. You are treating a patient with hyperbaric oxygen and he starts to seize 45 minutes into his HBO treatment. Your new chamber operator starts to reduce the pressure in the chamber so he can get the patient out as quickly as possible. What do you do? a. Help him reduce pressure more quickly by opening the manual vent. b. Pick up the phone and call "code blue". c. Get the crash cart.
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d. Stop the the decompression and hold the chamber at the current depth. - ansd. NEVER decompress a chamber while a patient is actively seizing. You have completed a treatment for a patient who was complaining of an upper respiratory infection and you are ready to reduce the chamber pressure. the compression was long and difficult due to trouble equalizing the patient's right ear. Two minutes into the decompression, the patient starts to complain of right ear pain again. What is the likely cause of the problem? a. The upper respiratory infection caused the eustachian tube to swell which is what caused the compression difficulty. All the work equalizing caused more swelling to occur and now the eustachian tube is not venting out the compressed gas, which is growing due to Boyle's law. - ansa. Your 73 year-old patient in today for his 33rd HBO treatment. You overhear him telling another patient that he loves coming here because he has found his vision has improved over the last month and now he can read without his glasses. What is an appropriate response for you to interject into the conversation? a. "A lot of our patients are treated for vision problems" b. "This is unusual occurrence. We need to stop your treatments" c. " This is a common occurrence in people who receive in excess of 20 treatments. Most people return to pre-treatment levels within a couple of months. Don't get a new prescription for at least 2 months." - ansc. "This is common for people with more than 20 treatments. Don't get a new prescription for 2 months. It is common practice to have a patient take a decongestant tablet before an HBO treatment. One thing to take into consideration regarding taking a decongestant before an HBO treatment is: a. It will lower the patients blood pressure to unsafe levels. b. It will make the patient less able to hold urine during the 2 hour treatment. c. If taken too early, it could wear off before the 2 hour treatment ends, increasing the likelihood of a reverse block. d. Decongestants are contraindicated for patient's going to pressure greater than 2.4 ATA - ansc. Don't take to early. answer a. is wrong because decongestants actually increase blood pressure, answer b is false decongestants cause urinary retention. Decompressing the chamber while the patient is in the tonic phase of a seizure. a. Can cause a pulmonary barotrauma. b. Allows you to care for the patient appropriately. c. Should be done as quickly as possible. d. None of the above. - ansa. Never decompress the chamber if the patient is actively seizing or in the tonic phase of a seizure. Who is considered the "Father of pressure physiology"? a. Bert b. Haldane c. Behnke d. Boerema - ansa. Paul Bert did a lot of stuff in the 1800's if you don't know the answer guess "Paul Bert" Paul Bert is known for studies in all the following EXCEPT: a. High altitude hypoxia
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Fire rules change use of O2 in chambers? - ans When were the USNavy dive tables 5 & 6 published? DM 7 - ans First Cardiovascular surgery performed in a chamber? - ans UPTD defined by ______? HI 47 - ans1972 by Mr. Wright. Convert: Degrees Fahrenheit to Degrees Rankine. DM 14 - ansR = F + 460 Haldane Theory of Safe Decompression? DM 30 - ansBubble formation and DCS could be avoided if no tissue were ever allowed to exceed twice the absolute pressure. Explain the: Paul Bert Effect. DM 3 - ansOxygen is toxic when breathed under pressure for any length of time. Greater than 33 ft. has been termed "Paul Bert Effect" Explain: Lorraine Smith Effect. DM - ansPulmonary oxygen toxicity is a direct time/dose relationship on the lungs caused by a direct effect of O2 on the lungs, blockage of airways, increased CO2, pulmonary surfactant changes, enzyme interference and an inert as effect. Convert: Fahrenheit = Celsius - ansC = (F - 32)/ 1. 100F - 32= 68 68/ 1.8= 38c Convert: Celsius into Fahrenheit - ansF = (C x 1.8) + 32 Quick way to convert Celsius into Fahrenheit - ansDouble degrees C then add 32 Age? Why? DM 41 - ansIncreases susceptibility. Due to vacuum phenomenon at joints Colds? Why? DM 37 - ansIncreases susceptibility. Blocks terminal bronchiole, cause rupture and micro-air embolism. Exercising "PRIOR" to diving? Why? DM 38 - ansIncreases susceptibility. Causes tribonucleation. Exercising (working) "AT DEPTH"? Why? DM 38 - ansIncreases susceptibility. Accelerates inert gas uptake. Exercising "AFTER" decompression? DM 40 - ansIncreases susceptibility. Causes tribonucleation. Hypothermia during decompression? Why? DM 40 - ansIncreases susceptibility.
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Reduces gas uptake. Obesity? Why? DM 41 - ansIncreases susceptibility. Due to nitrogen solubility in fat deposits. 9 x that of skinny person. Women who are not in top shape vs. men. DM 157 - ansIncreases susceptibility. Higher fat deposits. Adaption (frequent exposure with in 10 days)? Why? DM 38 - ansDecreases susceptibility. Exercise (light) "DURING" decompression. DM 40 - ansDecreases susceptibility. It warms a diver who then off gases more nitrogen. Fetus vs. Mother? DM 159 - ansFetus is at less risk for DCS than mother. Due to xxxxxxxxxx Hypothermia at depth? DM 40 - ansDecreases susceptibility. Cold reduces nitrogen absorption. How many Cubic feet of O2 do we consume in 1 hour? HI 71 - ans1 cubic foot of O2 consumed in 1 hour. How many cubic feet of CO2 do we produce in 1 hour? HI 71 - ansWe produce 1 cubic foot of CO2 in one hour. Dr. Haldane considered longest body tissue half-time N2 uptake, ____(time). DM 4 - ans60 minute longest body tissue half-time Nitrogen uptake. USN has 120 minute. Table 5 recompression dive time. DM 228 - ans2 hours 15 minutes. for Table 5 recompression. Depth 60 feet USNavy standard air-compression table based on ____ time, assumes N2 saturation DM 4 - ans12 hours considered ???? USNavy Exceptional exposure tables based on total body saturation. time of ____ hours. DM 4 - ans24 hrs USNavy Exceptional exposure table At what point is the human body completely saturated? Decompression time no different for days or weeks on water. DM 6 - ans>24 hrs Myopia may develop after ___-____ (time) of daily hyperbaric oxygen treatments. DM 85 - ans2-4 weeks of daily hyperbaric treatments may cause Myopia.
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DM 206 - ans90 mm of mercury (mmHg) differential change. What depth change causes 90 mm of mercury (mmHg) differential change? DM 206 - ans3.9 ft. of depth At what mm of mercury (mmHg) does the ears tympanic membrane rupture? DM 206 - ans100 mm to 500 mm of mercury differential change How much water vapor is produced in the lung? Exam book pg. 26 - ans47 mmHg How much CO2 is produced in the lung while breathing air? Exam book pg. 26 - ans50 mmHg How much CO2 is produced in the lung while breathing oxygen? Exam book pg. 26 - ans40 mmHg What is the mechanism where Nitrogen causes narcotic effect ( narcosis) on the body? DM 72 - ansThe site of the action is at the synapses or nerve junctions. The raised pressure of Nitrogen at depth, interferes with electricochemical mechanisms necessary for the transfer of the electrical potential across the synaptic gap of the central synapses. What detmines the RATE of development of Oxygen toxicity? DM 82 - ansThe rate of development of toxic effects is determined by the oxygen partial pressure (pO2) rather the oxygen percentage of the inspired gas. How does Oxygen toxicity actually kill someone? DM 82 - ansOxygen toxicity is caused by the productIon of free radical intermediates such as: superoxide anions, hydrogen peroxide, hydroperoxy and singlet oxygen. What does UPTD stand for? HI 49 - ansUnit Pulmonary Toxicity Dose What does UPTD measure? HI 49 - ansConservative method to compare the Net effect of various combinations of O2, pressure and time. Why do hyperbaric attendants go on and off oxygen? DM 86 - ansThe most effective and practical means for extension of oxygen tolerance in humans is the systematic alternation of oxygen exposure intervals with relatively brief normoxic intervals. Why is Hyperbarics used for Carbon Monoxide poisoning patients? DM 88 - ansHyperbaric Oxygen use HASTENS DISSOCIATION beyond a rate achievable by breathing pure O2 at sea level. Especially anyone who has lost consciousness,which is an indicator that they may develop neurological sequelae. What does hyperventilation do for the body? DM 64 - ansHyperventilation slightly increases the level of alveolar and arterial pO2, but this does not appreciably increase the blood O2 content. Why does hyperventilation not appreciably increase blood O2 content. DM 64 - ansBecause the hemoglobin saturation in the arterial blood is almost 100% during normal ventilation. What is the basic mechanism that causes "Shallow water Black Out"? DM 105 - ansHyperventilation reduces the partial pressure of arterial carbon dioxide(PaCO2) such that the breath hold break point is prolonged sufficiently for hypoxemia to occur before the individual is forced to breath. The hypoxemia in turn causes the person to lose consciousness.
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What are the 5 different ways that a diver may pass out. (Shallow water Black Out). HI - ans1) Going to deep for too long, using up fuel (O2)
- Ascending, and dropping the partial pressure of what O2 in the respiratory center after allowing it to get too low at depth.
- Reaching the surface with high arterial Carbon Dioxide tension, taking a breath, dropping the PCO2 quickly can cause the blood pressure to drop and the diver to pass out.
- Shifting the body from inverted position to the upright position will take blood and O from an already Hypoxic brain and cause black out.
- Hyperventilating before breath hold diving. How is a fetus affected during recompression? DM 155 - 158 - ansLess risk of DCS than mother. Studies on pregnant hamsters using Navy dive table 6 showed no increase rate of birth defects in the offspring. What are "Niggles"? DM 177 - ansDivers with DCS report much less sensations of fleeting aches and odd feelings prior to the development of the classic type DCS pain. What is DCS type 1? - ans... What is DCS type 2? - ans... What is the order of "slow" tissue half times to "fast" tissue half times? DM 172 - ansSLOW> Adipose tissue, Spinal Cord, Cerebrum, Skin, Striated muscle, Kidney <FAST Why are divers with CNS DCS not cured by recompression and then able to regain use of legs? DM 181 - ansSpinal cord bubble formation takes place in a lake versus stream of arterial flow. Even though a bubble may be reduced in size during recompression, it might not flow out of the "lake" and there is less venous flow through the "lake area" to flush it out. Why do you hear about the "Bends" in joints and spinal cord but not in the brain? Give 3 reasons. DM 223 - ans1) DCS of the brain tissue does occur but is harder to diagnose and is often over shadowed by DCS where the spinal cord paraplegia is involved.
- Brain injury presents itself as a stroke. Many divers who die of "AGE" (Arterial Gas Embolism) are given a coroner's diagnosis of drowning.
- Also joint pain presents itself where nitrogen bubbles in the brain are not as constricted and do not cause a specific pain. When do you use Table 5 vs. Table 6 for recompression treatment? DM 228 - ansSubjective. Table 5 has a higher recurrence of symptoms. USN Diving Manual says that Table 5 is to be used for "pain only" DCS if symptoms resolve in 10 minutes at 60 ft. If they persist after that time extend to Table 6. How does the recompression to 45 ft and breathing 100% O2 the preferred method for "wound Care Patients"? HI 40 - ansEnough pressure to saturate the blood with O2 and rapidly deliver it to tissues which are deprived of adequate blood flow. Does not have the worries of Oxygen Toxicity of a deeper profile and can be done for a longer time. Why should you not talk unnecessarily to tender at 1.9 ATA? HI 41 - ansIt causes the Tender to skip breath, which accelerates arterial carbon dioxide buildup.
