By Susan Jett Lawson RCP, RRT-NPS RC Educational Consulting Services, Inc. 16781 Van Buren Blvd, Suite B, Riverside, CA 92504-5798 (800) 441-LUNG / (877) 367-NURS www.rcecs.com
COURSE DESCRIPTION This course, which is designed primarily for Emergency Department medical personnel and those working with pulmonary medicine, focuses on the indications, rationale and application of heliox therapy. We will review the physical properties of helium, which is the basis for the effectiveness of heliox in the treatment of airway obstruction. Suggested procedures will be described to assist the Emergency Departments and Respiratory Care Departments in formulating specific guidelines for the administration of heliox. BEHAVIORAL OBJECTIVES UPON COMPLETION OF THE READING MATERIAL, THE PRACTITIONER WILL BE ABLE TO: 1. State the reasons that the use of heliox is on the increase. 2. List ten common uses for heliox. 3. Describe the physical properties of helium and heliox that provide the beneficial effects for our patients. 4. List five factors that determine, or affect, the behavior of gases flowing through an orifice and relate these to resistance in the airway and administration of heliox. 5. Describe the appropriate equipment required to administer heliox therapy. 6. Outline the required patient assessment parameters during the administration of heliox. 7. Outline the general heliox administration procedures. COPYRIGHT 2001 BY RC EDUCATIONAL CONSULTING SERVICES, INC. TX 5-360-009 AUTHORED (2001) BY SUSAN JETT LAWSON RCP, RRT-NPS REVISED (2004) BY SUSAN JETT LAWSON RCP, RRT-NPS REVISED (2007) BY MICHAEL R. CARR, BA, RRT, RCP ALL RIGHTS RESERVED This course is for reference and education only. Every effort is made to ensure that the clinical principles, procedures and practices are based on current knowledge and state of the art information from acknowledged authorities, texts and journals. This information is not intended as a substitution for a diagnosis or treatment given in consultation with a qualified health care professional. This material is copyrighted by RC Educational Consulting Services, Inc. Unauthorized duplication is prohibited by law. 2
TABLE OF CONTENTS HISTORY... 4 INDICATIONS AND RATIONALE FOR HELIOX THERAPY... 4 VARIOUS APPLICATIONS OF HELIOX AND RESEARCH UPDATE... 4 SUMMARY OF SPECIFICALLY STATED CLINICAL BENEFITS AND MEASUREMENT OF OUTCOME... 6 PHYSICAL PROPERTIES OF HELIUM AND HELIOX... 7 EQUIPMENT REQUIRED TO PROVIDE HELIOX THERAPY... 8 PROCEDURE / COMPETENCY... 12 SUMMARY... 15 SUGGESTED READING AND REFERENCES... 16 This material is copyrighted by RC Educational Consulting Services, Inc. Unauthorized duplication is prohibited by law. 3
HISTORY I n the 1930 s an American physician, Alvan Barach, not only developed methods of oxygen delivery such as CPAP/PEEP, but in 1934 established the value of low-density gas therapy. At that time heliox played a notable but limited role in medicine. Doctor Barach developed this helium-oxygen mixture and related methods as an approach to treating asthma and obstructions of the larger airways. When sympathomimetics became the acceptable treatment for bronchospasm the use of heliox lost its popularity. Bronchodilators, antihistamines, corticosteroids can fail in the treatment of some patients with bronchospasm. Practitioners must be willing to reintroduce the use of heliox as an alternative for those asthmatics with respiratory acidosis who do not respond to conventional treatment. Heliox is considered a cost effective way in which to treat airway obstruction. INDICATIONS AND RATIONALE FOR HELIOX THERAPY The most common clinical application is to increase oxygenation, in conjunction with sympathomimetic administration to decrease bronchospasm. Mixing helium with oxygen results in improved gas flow through the larger airways. This is a cause of the low gas density of helium. The breathing of a low-density gas requires less driving pressure for that gas to flow in the large airways, which results in decreased resistance and inspiratory effort from the patient. The work of breathing by the patient is then lowered. In conjunction with mechanical ventilation, studies have shown a decrease in peak inspiratory pressures for required tidal volumes. Unfortunately, these outcomes do not happen in all patients and it cannot be predicted which patients will have the best end results. VARIOUS APPLICATIONS OF HELIOX AND RESEARCH UPDATE Used with anesthesia to reduce pressures when small diameter endotracheal tubes are used. Pressures decrease by half with an 80%/20% heliox mixture. Used for short-term therapy when there is major airway obstructions (such as laryngeal or tracheal tumors). It s providing palliative therapy until definitive treatment can be accomplished. Some literature states this concentration must be > 50% Helium. The most common use of heliox to-date, which is discovered in most of the literature, is to reduce upper airway resistance in cases such as, postextubation stridor. One pediatric study indicated that children with post extubation stridor had reduced respiratory distress when breathing a heliox mixture rather than an enriched oxygen source. The latest National Institutes of Health investigation into using heliox mixtures for the acute asthmatic came to the conclusion that there is no evidence to support the This material is copyrighted by RC Educational Consulting Services, Inc. Unauthorized duplication is prohibited by law. 4
administration of heliox mixtures to treat the acute asthmatic in the emergency department, whether it is an adult or a child. As you know, clinical practice and evidence of patient improvement does not always agree with the scientific evidence. The use of a 65/35 % or 70/30 % mixture of helium to oxygen respectively is used in a heliox protocol for the acute asthmatic refractory to the conventional bronchodilator protocol at the Jewish Heart and Lung Institute. The director of the cardiopulmonary department reveals various studies to support this therapeutic modality. Exacerbation of COPD (emphysema/chronic bronchitis) to reduce airway resistance thereby decreasing functional residual capacity and improving CO 2 removal. The latest research indicates that there is insufficient evidence to support the use of helium-oxygen mixtures in the treatment of COPD exacerbations whether in conjunction with mechanical ventilation or other therapeutic modalities. In studies that involve spontaneously breathing asthmatics, breathing heliox decreases pulsus paradoxus, decreases PaCO 2 and increases peak flow. Heliox is also used in the treatment of acute respiratory failure in patients with asthma. Used in conjunction with hyperbaric oxygen treatments. At high barometric pressures because of the toxic effects of oxygen, alternative gas mixtures such as heliox are breathed. Some patients show improvement when receiving heliox via mechanical ventilation. Taking into consideration that mechanical ventilation can cause barotrauma by forcing volume/pressure into airways that are inflamed or in spasm and congested, it is recognized that using heliox instead of the conventional gas mixture (increased oxygen with room air) lowers the peak airway pressures. In addition, the for mentioned pathological factors lead to air trapping which can further compromise the patient s ventilatory status. With heliox mixtures, the flow of gas is improved during inspiration and expiration; therefore an additional positive aspect of heliox is the ability to decrease air trapping, with a resulting decrease PaCO 2. Increased resistance equals increased pressures and the sequel can be air leaks such as pneumothorax. The clinician may conclude that using a heliox mixture during mechanical ventilation decreases the work of breathing. Heliox breathing via a ventilator post operatively in a cardiac surgery patient has been reported to increase oxygenation and dynamic compliance. Many adult ventilators are being tested, the hope is that outcomes prove positive, and a ventilator is found that will deliver ventilation accurately with heliox. Neonatal ventilators such as the Drager Babylog 8000plus can provide IMV with heliox, but it cannot detect neonatal triggering efforts with the hot wire flow sensor it has. One new adult critical care ventilator produced by VIASYS Critical Care, the AvEA, has the capability of delivering heliox accurately. The flow regulation and blending This material is copyrighted by RC Educational Consulting Services, Inc. Unauthorized duplication is prohibited by law. 5
of gases is regulated by software designed to specifically accommodate heliumoxygen mixtures. Now that there is finally a ventilator able to provide the modality, maybe researchers can concentrate on studying the clinical outcomes of the therapy instead of just how to deliver heliox. The AvEA is also capable of providing noninvasive positive pressure ventilation. It does have leak compensation. Therefore, the application of heliox during NIPPV may be researched as well. A study was published in 2001 that aligned the use of noninvasive positive pressure ventilation with the administration of 80% helium/20% oxygen mixture. The ventilators used for the study were not compensated for heliox flow, therefore the ventilators functioned erratically and clinical outcomes could not be studied. Low concentrations (<5%) are used in pulmonary function testing. In higher concentrations (>50%) it is used medically for its low-density properties in palliative treatment of large airway obstruction. There are study models that report facilitating resolution of pneumothoraces with the delivery of heliox. Commercially, helium is used a nuclear reactor coolant, in cryogenic research as a shield ion arc welding, in silicon and germanium crystal-growing atmosphere in lighter-than-air craft and for breathing mixtures in deep-water diving. Used in the treatment of bronchopulmonary dysplasia (BPD). Used in the treatment of bronchiolitis. SUMMARY OF SPECIFICALLY STATED CLINICAL BENEFITS AND MEASUREMENT OF OUTCOME Decreased work of breathing in patients with asthma (plethysmography and esophageal balloon measurements) Decreased work of breathing in patients with fixed airway obstruction (dyspnea index) Improved ventilation (decreased PaCO 2 in ABG) Decreased barotraumas (reduced peak and plateau airway pressures) Increased tidal volumes (spirometric measurement) This material is copyrighted by RC Educational Consulting Services, Inc. Unauthorized duplication is prohibited by law. 6
Reduced I:E ratios (timed measurement) Improved homogeneity of gas distribution (by creating a more laminar flow) Movement of the equal-pressure point of the airways upstream PHYSICAL PROPERTIES OF HELIUM Natural gas containing up to 2% helium is found in wells in the southern United States. Other wells are located in Canada and the Black Sea. It is refined through a process of liquefaction and purification, resulting in a product that is 99.9% pure. Helium can also be obtained from the atmosphere by fractionation. Helium is the second lightest element in the atmosphere. It is chemically inert, nontoxic, tasteless and nonflammable. It is a rare gas, having a concentration of only 5 ppm. The symbol for helium is He. Viscosity is 194.1 X 10 (-6) Specific gravity 0.138 Boiling point 268.9C Critical temperature 267.9 C Critical pressure 731.4 psia No triple point a situation in which a given substance may exist in solid, liquid and vapor forms at the same time. Helium s relative molecular mass is 4.0 and its density is 0.165kg/mm3. Oxygen has a relative molecular mass of 31.99 and a density of 1.32kg mm3. This difference in relative molecular mass and density between oxygen and helium tells us that helium atoms are smaller and lighter than oxygen atoms. Helium is nonreactive with body tissues. This material is copyrighted by RC Educational Consulting Services, Inc. Unauthorized duplication is prohibited by law. 7
Helium is relatively insoluble in body fluids. EQUIPMENT REQUIRED TO PROVIDE HELIOX THERAPY Heliox can be delivered via well-fitted simple O 2 mask, demand valve, blender with wellfitting non-rebreathing mask, CPAP circuit or ventilator. Nasal cannulas are ineffective and infant hoods are suboptimal. Ventilator (invasive or noninvasive). An example of a volume ventilator that incorporates the option of ventilation with Heliox is the AVEA volume ventilator. The Critical Care Division of VIASYS Healthcare Inc, Palm Springs, Calif, has received FDA approval for its heliox delivery system. This feature is now available from the AVEA Ventilator System, the first critical care ventilator designed to deliver heliox gas. Practitioners can deliver any desired concentration of heliox with ease and accuracy to aid in the treatment of patients with airway obstruction or severe bronchospasm. AVEA uses a patented Smart connector to accept an 80/20-heliox supply. All volumes (numeric and graphic) are automatically compensated for accurate display, eliminating cumbersome bedside calculations. Helium/oxygen cylinder (He/O 2 ) Color-code: brown and green 80% helium and 20% oxygen mixture 70% helium and 30% oxygen mixture AvEA Comprehensive Ventilator Compliments of Viasys Critical Care This material is copyrighted by RC Educational Consulting Services, Inc. Unauthorized duplication is prohibited by law. 8
Heliox regulator Heliox Regulator E cylinder The helium/oxygen mixture will have pins in the 2 and 4 locations according to the pin index safety system (PISS). Oxygen flowmeter Adjustments are required due to the behavior of gases flowing through the orifice of an oxygen flowmeter. Flow Dynamics 22 : In order to calculate the actual flow: 80%/20% mixture: Multiply the observed flow by 1.8 to get the actual flow. The concentration is mainly used for normoxic patients. 70%/30% mixture: Multiply the observed flow by 1.6 to get the actual flow. This concentration is used for the hypoxic patient. There are factors that determine, or effect, the behavior of gases flowing through an orifice: Law of continuity: The product of the cross-sectional area of a system and the velocity for a given flow rate is constant Velocity versus flow: Velocity is the speed with which movement between two points occurs. This material is copyrighted by RC Educational Consulting Services, Inc. Unauthorized duplication is prohibited by law. 9
Resistance to gas flow: In general, resistance is defined as the force (pressure) necessary to maintain a specific flow in a particular system. Series and parallel resistances: Series resistance are resistance elements arranged sequentially in the direction of flow Conductance: Conductance is the capability of a system to maintain flow Types of flow: Laminar flow is smooth, even, non-tumbling flow. Turbulent flow is a rough, tumbling, uneven flow pattern. Tracheobronchial flow is a combination of areas of laminar and turbulent flow. Reynold s number: Reynold s number is a dimensionless number that indicates whether flow through a system is laminar or turbulent Poiseuille s law: Defines the factors that affect the pressure required to maintain laminar flow. Bernoulli effect: As a gas moves through a free-flowing system, transmural pressure is inversely related to velocity of the gas. Jet mixing: The use of a constant flow of gas (jet) to entrain a second gas. Driving pressure: The pressure necessary to maintain flow between point A and B in a gas flow system. An important factor is that flowmeters used at significantly different altitudes may require correction. The most significant factor regarding helium-oxygen mixtures is that flow through an orifice is proportional to the inverse of the square root of the density of the gas. If pressure and the diameter are constant, flow increases with lower-density gases and vice versa. This relationship involving density is important to consider if clinicians administer gases of different densities when using oxygen flow devices. Calculations are needed if a specific helium/oxygen flowmeter is not available and accurate flows are needed. You can also bleed in more oxygen from another source, but it changes the density of your gas mixture. This material is copyrighted by RC Educational Consulting Services, Inc. Unauthorized duplication is prohibited by law. 10
Another, less common concentration is 60%/40%. Note that accurate flows are not required when administering heliox via nonrebreathing mask because the flow is set to meet or exceed the patient s peak inspiratory flow or demand. It is also not required via ventilator as the mixture is given via H-cylinder at 50 PSI with a previously mixed cylinder of 60% He and 40% O2 or 70% He and 30% O2. Non-rebreathing masks should be set to keep the reservoir bag nearly full at all times. Remember to always fill the reservoir bag prior to placing the mask on the patient s face. The precise flow is not ordered, but the flow is adjusted to meet the patient s breathing demands. If the patient complains of shortness of breath (SOB) consider increasing the flow. An investigative group from Hines, Illinois, studies aerosol delivery of an albuterol and normal saline mixture. They concluded that when using a large volume nebulizer, HeO 2 introduced as a secondary gas source improved the efficiency of the nebulizer delivery system. The concentration of the heliox mixture was 70% helium, 30% oxygen. The oxygen as the primary gas source was ran at 13 LPM, the heliox at 22 LPM. Clinical correlation of outcome was not revealed. Heliox mixtures can affect nebulizer function. Smaller particle size, decreased nebulizer output and increased length of aerosol delivery have been reported. The use of heliox mixtures to improve aerosol deposition of beta agonists was discussed in the March, 2003 issue of Respiratory Care. All factors being optimal, the outcome of the discussion was that the heliox did provide better aerosol deposition, but that the beneficial effects of the heliox itself lasted only as long as the patient was receiving this therapeutic gas. An example of a nebulizer that can be used to deliver aerosol medications while using heliox as a source gas is the Hope nebulizer. This material is copyrighted by RC Educational Consulting Services, Inc. Unauthorized duplication is prohibited by law. 11
Hope Nebulizer Compliments of: B & B Medical Signs of increased work of breathing (WOB) include: Agitation Increased use of accessory muscles of breathing Diaphoresis Increased respiratory rate Increased heart rate Increased blood pressure All connections must be tight A humidifier may be used if appropriate for the set up. An aerosol may also be used, but if an air-entrainment type nebulizer is used, make sure the port is set to deliver 100% source gas. PROCEDURE / COMPETENCY 1. Check physician orders. Orders must only contain Heliox treatment and the indication for the treatment. Review the orders for appropriateness. Note indication for specific Heliox This material is copyrighted by RC Educational Consulting Services, Inc. Unauthorized duplication is prohibited by law. 12
treatment. Review chart if applicable. 2. If patient is hypoxic, use the 70% He 30% O 2 mixture. Studies reveal that a minimum time of twenty (20) minutes of breathing the heliox mixture is required to observe its full effect. Several studies documented patient s breathing adjunctive heliox therapy for up to 48 hours while definitive treatment was in process. 3. Wash your hands. 4. Gather equipment: Heliox cylinders with appropriate regulator and flowmeter. Humidifier (if higher flows are required, this must be eliminated) Non-rebreathing mask. 5. Assemble and check for proper function the equipment. 6. Identify and verify the correct patient. 7. Explain the procedure to the patient. Be brief, but explain the benefits of heliox in terms the patient can understand so they will cooperate. 8. Turn on Heliox flow to the non-rebreathing mask until the reservoir is full. 9. Apply non-rebreathing mask to patient. Adjust the device as best you can to an acceptable level of comfort to the patient. 10. Adjust the flow rate to keep the non-breathing reservoir from collapsing more than 2/3 of full during the patient s peak demand. 11. Monitor patient for the following: Breath sounds pre and post. Heart rate pre, during and post. Respiratory rate pre, during and post. Coughing. Level of respiratory distress, both objective and subjective. Assessment of pulsus paradoxus (if present). This material is copyrighted by RC Educational Consulting Services, Inc. Unauthorized duplication is prohibited by law. 13
Assessment of electrocardiogram for arrhythmias. SpO 2 (pulse oximetry). 12. When treatment is complete, clean up your equipment. 13. Ensure patient s comfort and safety. 14. Wash your hands. 15. Document the procedure, monitoring parameters, any adverse reactions and outcome. 16. If using continuous bronchodilator therapy (CBT) in conjunction with heliox delivery, the facility s procedure and guidelines for CBT administration must also be used. The following set-up is suggested to deliver heliox with bronchodilator therapy. Attach a Y to the valved oxygen mask. One side of the Y is to have the nonrebreathing reservoir bag with the one-way valve attached. The other side of the Y is to the nebulizer. The oxygen tubing from the nonrebreather is attached to a heliox mixture, as is the tubing from the nebulizer. Of course, additional oxygen may be provided via nasal cannula. Nebulized Medication with Heliox Set-up Nebulized Medication with Heliox Set-up When using heliox during mechanical ventilation, other indicators of success may be measured in addition to those mentioned earlier for treatment of airway obstruction. They not only include ABG with a decreased PaCO 2, but also decreased peak and plateau pressures and decreased auto- PEEP (intrinsic end-expiratory pressure). This material is copyrighted by RC Educational Consulting Services, Inc. Unauthorized duplication is prohibited by law. 14
SUMMARY Ahelium-oxygen mixture (heliox) has been clinically shown to increase oxygenation, decrease bronchospasm and decrease ventilating pressures and air trapping. The mixture is most commonly delivered via non-rebreathing mask, sometimes with an in-line nebulizer. Many studies have been conducted to establish, with certainty, that heliox is a valuable treatment especially in the management of patients with acute bronchospasm. Helium is inert and nonreactive with body tissues. A heliox mixture is lighter than an oxygen/nitrogen mixture and is thought to carry oxygen and nebulized medications past airway obstructions. Concentrations of heliox mixtures less than 60% helium and 40% oxygen are thought to be ineffective in accomplishing this goal and are not advised. Research is continuing in the use of heliox. Many of us will continue to use or begin to use heliox therapy based on the studies that exist today and our clinical observations. Many will continue to adapt ventilators and other equipment to deliver heliox in the most effective manner we know. Unlike the past, though, now studies may be conducted with a ventilator that may be used invasively or noninvasively to deliver heliox mixtures reliably. This material is copyrighted by RC Educational Consulting Services, Inc. Unauthorized duplication is prohibited by law. 15
SUGGESTED READING AND REFERENCES 1. All-Net Pediatric Critical Care Textbook (7/5/99). Status Asthmaticus/Heliox (heliumoxygen 60:40 or 80:20). 2. American Health Consultants (1995). Asthma: Disease State Management Resource. Atlanta, GA. 3. Branson, R., Hess, D., Chatburn, R. (1999). Respiratory Care Equipment. (2 nd ed). Philadelphia: Lippincott, Williams and Wilkins. 4. Brown, M. Bench Test of the Drager Babylog 8000plus Neonatal Ventilator with Heliox Mixtures, 2002. 5. Burton, G., Hodgkin, Ward, J. (1997). Respiratory Care, A Guide to Clinical Practice (4 th ed). Philadelphia: Lippincott. 6. Chatmongkolchart, S., Kacmarek, R., Hess, D. Heliox Delivery with Noninvasive Positive Pressure Ventilation: A Laboratory Study. Respiratory Care, March 2001. 7. Chest 1995 Mar; 107(3): 757-60. Heliox therapy in acute severe asthma. 8. Fink, J. Helium-oxygen: An Old Therapy Creates New Interest, The Journal for Respiratory Care Practitioners. April/May 1999. 9. Heart Lung 1996 Mar-Apr; 25(2): 155-7. Heliox inhalation in status asthmaticus and respiratory academia: a brief report. 10. J. Pediatr 1997 Feb; 130(2): 217-24. Inhaled helium-oxygen revisited-effect of inhaled helium-oxygen during the treatment of status asthmaticus in children. 11. MacIntyre, N., Branson, R. Mechanical Ventilation. W.B. Saunders Co., Philadelphia. 2001. 12. Phelps, H. Heliox Therapy in severe acute asthma. Cardiopulmonary Newsletter, Fall 2001. 13. Pollack, R., Rowe, R., Walters, E.H. Heliox for treatment of exacerbations of chronic obstructive pulmonary disease (Cochrane Review), The Cochrane Library, Issue 1, 2003. 14. Respiratory Care Nov. 1997. Heliox in the treatment of airflow obstruction: a critical review of the literature. 15. Respiratory Care Current Trends in Neonatal and Pediatric Respiratory Care. March 2003. Vol. 48 No. 3. 16. Ritchie, J., Hagel, C.L. Asthma: A new look at helium therapy. Asthma: The Disease State This material is copyrighted by RC Educational Consulting Services, Inc. Unauthorized duplication is prohibited by law. 16
Management Resource, RN Magazine, September 1994. 17. Rodrigo, G., Rodrigo, C., Pollack, C., Travers, A. Helium-oxygen mixture for nonintubated acute asthma patients. Ncbi.nlm.nih.gov Cochrane Database. 18. Scanlan, C. L., Wilkins, R., Stoller, J. (1999). Egan s Fundamentals of Respiratory Care. (7 th ed). St. Louis: Mosby. 19. Sill, J. (1995). Respiratory Care Registry Guide. St. Louis: Mosby. 20. The Journal for Respiratory Care Practitioners Oct/Nov, 1998. Helium-oxygen mixtures and status asthmaticus. 21. The Journal for Respiratory Care Practitioners Apr/May, 1999. Helium-Oxygen: An old therapy creates new interest. 22. Kacmarek, R. M. The Essentials of Respiratory Care 4 th Edition 2005. Elsevier Mosby This material is copyrighted by RC Educational Consulting Services, Inc. Unauthorized duplication is prohibited by law. 17
POST TEST DIRECTIONS: IF COURSE WAS MAILED TO YOU, CIRCLE THE MOST CORRECT ANSWERS ON THE ANSWER SHEET PROVIDED AND RETURN TO: RCECS, 16781 VAN BUREN BLVD, SUITE B, RIVERSIDE, CA 92504-5798 OR FAX TO: (951) 789-8861. IF YOU ELECTED ONLINE DELIVERY, COMPLETE THE TEST ONLINE PLEASE DO NOT MAIL OR FAX BACK. 1. The clinical benefit(s) of helium mixture(s) is(are): I. increase I:E ratios (timed measurement) II. decrease work of breathing in patients with asthma III. improve ventilation IV. it can be combined with carbogen a. I only b. II and IV c. II and III d. II, III and IV 2. Which of the following may be the reason heliox therapy has increased: a. the limitations of bronchodilators, ventilators and steroids have been realized b. patients are becoming less responsive to sympathomimetics c. it is less expensive to deliver than a nebulized medication d. some patients prefer heliox therapy to oxygen therapy 3. Heliox therapy is used in exacerbation of emphysema and chronic bronchitis primarily to: a. provide oxygen to restricted airways b. reduce airway resistance, thereby decreasing FRC and improving CO 2 removal c. decrease the patient s use of corticosteriods d. treat the large fixed airway obstruction This material is copyrighted by RC Educational Consulting Services, Inc. Unauthorized duplication is prohibited by law. 18
4. Heliox is delivered most effectively via: I. mechanical ventilation II. non-rebreathing mask III. ventimask IV. nasal cannula V. aerosol mask a. I & V b. II & IV c. All of the above d. I & II 5. Signs of increased work of breathing include, but are not limited to: I. increased respiratory rate II. increased heart rate III. increased blood pressure IV. decreased body temperature V. diaphoresis a. I, II, III, V b. I, II, III, IV c. II, III, IV d. III, IV, V 6. During heliox therapy, the patient must be monitored for the following: I. pre and post breath sounds II. clubbing of finger tips III. pre and post heart rate IV. pre and post respiratory rate V. level of respiratory distress a. I, II, III, IV b. II, III, IV, V c. I, III, IV, V d. III, & IV only 7. Low density gas therapy, such as heliox: a. has only been used in the last 10 years b. should only be used with extreme caution due to its side-effects c. was developed in the 1930 s d. should never be used in conjunction with bronchodilator therapy This material is copyrighted by RC Educational Consulting Services, Inc. Unauthorized duplication is prohibited by law. 19
8. The most beneficial effect of using heliox during mechanical ventilation is: a. prevention of barotrauma b. delivery of a bronchodilating agent c. increased oxygenation of the patient d. as an alternative gas source to prevent oxygen toxicity 9. The most common applications of heliox therapy are: I. during hyperbaric treatment II. to increase oxygenation III. to decrease bronchospasm in conjunction with sympathomimetics IV. to decrease pressures and air trapping in conjunction with mechanical ventilation a. I, II, III b. All of the above c. III & IV only d. II, III, IV 10. The recommended heliox mixture for the hypoxic patient is: a. 80% He, 20% O 2 b. 90% He, 10% O 2 c. 60% He, 40% O 2 d. 70% He, 30% O 2 11. When using heliox during mechanical ventilation, the primary indicators of success with this therapy may be measured by: I. Decreased PaCO 2 measurement II. Decreased peak pressures III. Decreased plateau pressures IV. Decreased intrinsic en-expiratory pressure a. I & II b. II & III c. I, II & IV d. All of the above 12. Specifically revealed clinical benefits of heliox include: a. Increased tidal volume measurements b. Decreased PaCO 2 c. Decreased work of breathing d. All of the above This material is copyrighted by RC Educational Consulting Services, Inc. Unauthorized duplication is prohibited by law. 20
13. Nebulizer function is affected by heliox mixtures because: a. The output of medication and diluent may decrease. b. It may deliver a smaller particle size. c. It may take longer for the aerosol mixture to nebulize. d. All of the above 14. Heliox breathing via a ventilator post cardiac surgery has been reported to: a. Increase oxygenation b. Increase dynamic compliance c. Increase the incidence of cardiac arrhythmia d. A & B e. B & C 15. Delivery of heliox has been noted to resolve pneumothoraces. a. True b. False SL: Test Version C This material is copyrighted by RC Educational Consulting Services, Inc. Unauthorized duplication is prohibited by law. 21
ANSWER SHEET NAME STATE LIC # ADDRESS AARC# (if applic.) DIRECTIONS: (REFER TO THE TEXT IF NECESSARY PASSING SCORE FOR CE CREDIT IS 70%). IF COURSE WAS MAILED TO YOU, CIRCLE THE MOST CORRECT ANSWERS AND RETURN TO: RCECS, 16781 VAN BUREN BLVD, SUITE B, RIVERSIDE, CA 92504-5798 OR FAX TO: (951) 789-8861. IF YOU ELECTED ONLINE DELIVERY, COMPLETE THE TEST ONLINE PLEASE DO NOT MAIL OR FAX BACK. 1. a b c d 2. a b c d 3. a b c d 4. a b c d 5. a b c d 6. a b c d 7. a b c d 8. a b c d 9. a b c d 10. a b c d 11. a b c d 12. a b c d 13. a b c d 14. a b c d e 15. a b SL: Test Version C This material is copyrighted by RC Educational Consulting Services, Inc. Unauthorized duplication is prohibited by law. 22
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