RT 3111 Respiratory Care Exam 1 Study guide

As previously discussed, infectious agents can be transmitted by a variety of means, including contact, vehicle, airborne, and vector routes. Identify the most probable means of transmission for the following infectious particles: • Pseudomonas aeruginosa organisms • HIV • Mycobacterium tuberculosis organisms • Rickettsiae sp.

(1) Pseudomonas aeruginosa is a highly motile, gram-negative bacillus found in the human gastrointestinal tract. It is a contaminant in many aqueous solutions (vehicle route). (2) Human immunodeficiency virus is transmitted through the exchange of body fluids (e.g., sexual contact) with an HIV-infected individual. (3) Tuberculosis is a chronic bacterial infection that is almost exclusively transmitted within aerosol droplets produced by the coughing or sneezing of an individual with active tuberculosis. (4) Rickettsiae spp. are small pleomorphic coccobacilli. Rickettsia spp. are responsible for diseases that are transmitted by lice, fleas, ticks, and mites.

Given the oxygen flow, determine total flow delivered to a patient via an air entrainment mask.

***Think of the majik box*** (100% & 21%) in the example below the instructor used 20 instead of 21 given FiO2, find ratio & total flow Order to deliver 40% O2 Air / O2 = 100-FiO2 / FiO2 - 20 = 100-40 / 40-20 = 60/ 20 = 3 / 1 = 3 parts air /1 part O2 If O2 flowmeter is set at 5L/m, you are entraining 15L/m Air. Total flow = 20L/m

How much O2 attaches to 100 mL of Hgb?

***This info was found online How much oxygen is in the blood? The amount of oxygen in the blood is calculated using the formula: [1.34 x Hb x (SaO2/100)] + 0.003 x PO2 = 20.8ml Oxygen is carried in the blood in two forms: dissolved and bound to hemoglobin. Dissolved oxygen obeys Henry's law - the amount of oxygen dissolved is proportional to the partial pressure. For each mmHg of PO2 there is 0.003 ml O2/dl (100ml of blood). If this was the only source of oxygen, then with a normal cardiac output of 5L/min, oxygen delivery would only be 15 ml/min. Tissue O2 requirements at rest are somewhere in the region of 250ml/min, so this source, at normal atmospheric pressure, is inadequate. Hemoglobin is the main carrier of oxygen. Each gram of hemoglobin can carry 1.34ml of oxygen. This means that with a hemoglobin concentration of 15g/dl, the O2 content is approximately 20ml/100ml. With a normal cardiac output of 5l/min, the delivery of oxygen to the tissues at rest is approximately 1000 ml/min: a huge physiologic reserve. Hemoglobin has 4 binding sites for oxygen, and if all of these in each hemoglobin molecule were to be occupied, then the oxygen capacity would be filled or saturated. This is rarely the case: under normal conditions, the hemoglobin is 97% to 98% saturated. The amount of oxygen in the blood is thus related to the oxygen saturation of hemoglobin. Taking all of these factors into account, we can calculate the oxygen content of blood where the PO2 is 100mmHg, and the hemoglobin concentration is 15g/L: [1.34 x Hb x (saturation/100)] + 0.003 x PO2 = 20.8ml As one would expect, this figure changes mostly with the hemoglobin concentration: when the patient is anemic the oxygen content falls, when polycytemic, it rises. In either case the O2 saturation of hemoglobin may be 97 - 100%, but there may be a large discrepancy in content.

Know the filling pressures of oxygen cylinders (fiber-wrapped vs. aluminum/steel)

...2200 psi fiber wrapped can be filled to 3,000psi , but these tanks are very expensive and are not as common *for calculation purposes all tanks full have 2200psi.

How is the majority of oxygen transported throughout the body?

..2 methods: 1st oxygen dissolved in the blood plasma, 2nd oxygen bonds with hemoglobin( Hgb or Hb)

Three staff RTs are given three separate requests to set up O2. (1) Mark has an order to transport Ms. Patel to radiology with O2. (2) Carmen needs to set up a pneumatically powered ventilator with O2 in the ambulatory clinic (where there are no O2 outlets). (3) Monica has to set up O2 therapy with a jet nebulizer for a patient in the intensive care unit (ICU). What equipment should each RT select?

1 Because he has to transport a patient using O2, Mark should select an E cylinder with an adjustable regulator that includes a Bourdon gauge (unaffected by gravity) or an integrated O2 cylinder that includes an adjustable flow restrictor. 2 Because pneumatically powered ventilators require 50 psig and no central outlets are available, Carmen needs a preset (50 psig) reducing valve and a large G/H O2 cylinder. 3 Because all modern ICUs have central wall outlets for O2, Monica need only select a flowmeter with the appropriate quick connect. A compensated Thorpe tube is required for metering flow through high-resistance equipment such as jet nebulizers. (al 908) al, Kacmarek et. Egan's Fundamentals of Respiratory Care, 10th Edition. Mosby, 032012. <vbk:978-0-323-08203-7#outline(37.5.3.2.3.1.2)>.

describe the Bernoulli Principle

1. gas flow through a tube 2. As velocity of gas goes up, lateral pressure goes down since the total energy principle is constant.

Based on the discussion of compressed gases, name the appropriate gas for each of the following situations: 1.Use as a refrigerant. 2.For reducing the work of breathing in a patient with airway obstruction. 3.To treat hypoxemia in a patient with chronic obstructive pulmonary disease. 4.For reducing pulmonary vasoconstriction, such as occurs in PPHN.

1.Carbon dioxide (CO2) 2.Helium (He) 3.Oxygen (O) 4.Nitric Oxide (NO)

What is a shunt?

1.to redirect the flow of a body fluid from one cavity or vessel to another. 2.a tube or device implanted in the body to redirect a body fluid from one cavity or vessel to another. ( Mosby 1702-1703) Mosby. Mosby's Dictionary of Medicine, Nursing & Health Professions, 8th Edition. Mosby, 122008. <vbk:978-0-323-04937-5#outline(19)>.

Bulk liquid oxygen supplies should not be closer than _________ to public sidewalks. a. 2 feet b. 4 feet c. 7 feet d. 10 feet

10 feet

What is the duration of oxygen flow from an H cylinder containing 1200 psi of oxygen when the flow to a nasal cannula is 4 L/min? a. 9 hours, 42 minutes b. 12 hours, 15 minutes c. 15 hours, 42 minutes d. 16 hours, 10 minutes

15 hours, 42 minutes

The gas flow delivered to a patient receiving a 70% : 30% (helium : oxygen) mixture is indicated on the standard oxygen flowmeter as 10 L/min. What is the actual gas flow delivered to the patient? a. 5.6 L/min b. 6.25 L/min c. 16 L/min d. 18 L/min

16 L/min (Page 82 and 83)

You are asked to transport a patient who is receiving oxygen from a nasal cannula at 4 L/min. The pressure gauge on the cylinder reads 1800 psi. How long will the cylinder provide the appropriate oxygen flow?

1800 psi × (0.28) ÷ 4 L/min = 126 minutes, or about 2 hours (Pilbeam 39) Pilbeam, Cairo and. Mosby's Respiratory Care Equipment, 8th Edition. Mosby, 022009. <vbk:9780323051767#outline(2.4.1.9.1.1)>.

What is the approximate partial pressure of inspired oxygen of room air if the barometric pressure is raised to 2 atm? a. 150 mm Hg b. 300 mm Hg c. 200 mm Hg d. 1520 mm Hg

300 mm Hg (Page 79)

What is the air : oxygen entrainment ratio for delivering 40% oxygen through an air entrainment mask? a. 2 : 1 b. 1 : 2 c. 1 : 3 d. 3 : 1

3:1 (Page 75)

Oxygen concentrators that use semipermeable membranes usually can provide what percentage of oxygen at flows of 1 to 10 L/min? a. 24% b. 40% c. 60% d. 100%

40%

Calculate the duration of the liquid oxygen supply if the liquid supply weighs 30 pounds and the oxygen demand is 4 L/min. a. 10 hours b. 23 hours c. 35 hours d. 43 hours

43 hours

Large piston air compressors used in bulk supply systems typically can provide working pressures of: a. 50 psi b. 75 psi c. 100 psi d. 120 psi

50 psi

Studies have shown that mustache and pendant cannulas can reduce the cost of oxygen therapy by as much as: a. 10% b. 30% c. 50% d. 80%

50% (Page 72)

How much water can gas hold @ 370C?

@ 370C gas may hold 44 mg of H2O per L @ 760mmHg (1 atm), 47 mmHg is due to water vapor pressure

Following standard procedure, the RT attaches a pressure-reducing valve to an O2 cylinder. When the RT opens the cylinder valve, gas leaking at or near the connection can be heard.

A leak usually indicates that the connection between the pressure-reducing valve and the cylinder outlet is not tight. If the cylinder outlet is a standard ASSS threaded connector, the connection is either cross-threaded or not properly seated and tightened. To solve this problem, the RT closes the cylinder valve and removes and reattaches the pressure-reducing valve, taking care to thread the connection properly and to tighten with a wrench. If the cylinder outlet is a pin-indexed connector, the RT closes the cylinder valve and removes the pressure-reducing valve. The RT checks to ensure that the nylon washer is present, in good condition, and properly fitted. The RT then reattaches the pressure-reducing valve, taking care to seat the connection properly and to hand tighten. If the leak continues after these corrective actions, it is likely that the pressure-reducing valve is malfunctioning and should be replaced. (al 903) al, Kacmarek et. Egan's Fundamentals of Respiratory Care, 10th Edition. Mosby, 032012. <vbk:978-0-323-08203-7#outline(37.5.3.1.4.1.2)>.

What is the goal of heliox therapy? What is it used to treat?

Administered in the Treatment of Obstructive Airway Diseases Gas of Lesser Density Can More Easily Bypass the Obstruction Gas Mixtures Are Available in 20/80% and 30/70% Oxygen-to-Helium Mixtures

Hyperbaric oxygen therapy is indicated for: a. Air embolism b. Hypercapnia (>60 mm Hg) c. Carbon monoxide poisoning d. Sinusitis (1) I and III only (2) II and IV only (3) I, II, and III only (4) II, III, and IV only

Air embolism and carbon monoxide poisoning (Page 78)

Which of the following devices is/are considered high-flow (fixed performance) oxygen delivery system(s)? a. Nasal cannula b. Nasal catheter c. Air entrainment mask d. Partial rebreathing mask (1) I and II only (2) I, II, and III only (3) III only (4) I, II, III, and IV

Air entrainment mask (Page 74)

Describe the 6 types of hypoxia we discussed in class.

Altitude Hypoxia-low PaO2-think Mt Everest! Anemic Hypoxia-low iron-chronic bleeding disorders Anoxic Hypoxia-type resulting from inadequate oxygen in inspired air or interference with gaseous exchange in the lungs. Autoerotic Hypoxia-Cerebral oxygen deprivation that a person self-induces Cerebral Hypoxia-Lack of oxygen supply to the brain,-traumatic birth, cardiopulmonary arrest. Histotoxic Hypoxia-due to impaired use of oxygen by tissues.

Given FiO2, atmospheric pressure, and PACO2 (or ETCO2), calculate the PAO2 using the alveolar air equation.

Alveolar Air Equation: Determines alveolar partial P of O2 PAO2 = FIO2 x (PB - 47) - (PACO2/0.8)

How long would a liquid oxygen supply weighing 10 pounds last if a patient were receiving oxygen through a nasal cannula at 2 L/min?

Amount of gass(liters)=(10 pounds ÷ 2.5 Ib/L) ×860 Amount of gas = 3440 L Duration of supply(minutes)=Amount of gas ÷Flow (in liters)Duration of supply=3440 L ÷(2 L/min) Duration of supply = 1720 minutes or about 28 hours and 40 minutes (Pilbeam 42) Pilbeam, Cairo and. Mosby's Respiratory Care Equipment, 8th Edition. Mosby, 022009. <vbk:9780323051767#outline(2.4.2.2.1.1)>.

How much O2 dissolves in 100 mL of plasma per mm Hg?

Amount of oxygen dissolved in the plasma is a function of Henry'sLaw At normal body temperature- 0.003ml O2 dissolves in 100ml of blood for every 1mmHg of PO2.

Alternating supply systems for medical gases that are used in hospitals should include a reserve supply for oxygen in case the primary system fails. How much reserve oxygen should be available? a. An average 8-hour supply b. An average day's supply c. An average 3-day supply d. An average week's supply

An average day's supply

What is the normal PaO2 range in a healthy adult?

Arterial values should be between 85 and 100 mmHg, Venous values should be between 30 and 40 mmHg.

What is the relationship between temperature & pressure?

As temperature increases, the velocity of gas molecules increases, which in turn causes an increase in pressure.

Difference between a Bourdon gauge and a Thorpe tube...Which is better for transport?

Bourdon Gauge Hollow coiled metal tube w/ elliptical cross section Commonly found on medical gas cylinders Bourdon gauge + adjustable reducing valve Reads P, but indicates flow Accurate only @ ambient P Back pressure causes flow to appear > actual Can't tell if O2 is flowing by looking @ gauge!!! Lightweight & not gravity-dependent There are 2 types of Thorpe Tubes Uncompensated thorpe tube flowmeter & Compensated thorpe tube flowmeter. *Uncompensated thorpe tube flowmeter Needle valve is proximal to tube Not compensated for back P P downstream may cause flow to appear < delivered **Compensated thorpe tube flowmeter Needle valve is distal to Thorpe tube Back P has no effect Ball "jumps" when attached to gas source

Which of the following is classified as a nonflammable gas that does not support combustion? a. Oxygen b. Carbon dioxide c. Helium d. Nitric oxide

Carbon dioxide

Know the U.S. tanks colors for various gases (O2, CO2, N2O, air, He/O2, CO2/O2)

Color coding O2 green (or white) CO2 gray N2O light blue C3H6 orange (extremely reactive) He brown CO2 + O2 gray & green He + O2 brown & green Air yellow

Be able to use the combined gas law to solve for missing variables...remember, if a value is constant, you can take it out of the equation! (Don't forget to convert to Kelvin!)

Combined Gas Law (a.k.a. general gas law) Combines Boyle's, Charles', & Gay-Lussac's Formula: P1 V1 / T1 = P2 V2 / T2

What do the markings on an oxygen cylinder signify?

Cylinder markings -Date tested -Inspector's mark -Passed inspection (+) -Next inspection in 10yrs (*) -Construction material (DOT 3AA or DOT 3AL) -Approved fill P (up to 10% > working P) -Serial # -Owner's stamp

What is the difference between a ducted ejector & a Venturi tube?

Ejectors (Ducted): use nozzle, viscous shearing, & vorticity to increase total flow. Ducted Ejectors Similar to Venturi except: Tube diameter does not Δ Purpose is to maintain high velocity (not restore lateral pressure) Velocity remains high, P remains constant Advantage: increased Pressure downstream has less effect on entrainment Used in nebulizers

Be able to determine duration of oxygen flow based on the p.s.i. of E & H cylinders.

Estimating the Duration of a Medical Gas Cylinder Supply The amount of time it will take a cylinder filled with compressed gas to provide a set flow rate of gas can be calculated with the following formula: Cylinder presure(psi)×Cylinder factor*Flow rate of gas/ (L/min)=Dutation of flow in minutes* Volume-Pressure Conversion Factor E Cylinder 0.28L/psi or 0.29 L/psi H Cylinder 3.14L/psi Don't forget to subtract -500psi Example You are asked to transport a patient who is receiving oxygen from a nasal cannula at 4 L/min. The pressure gauge on the cylinder reads 1800 psi. How long will the cylinder provide the appropriate oxygen flow? 1800 psi × (0.28) ÷ 4 L/min = 126 minutes, or about 2 hours *The cylinder factor represents the relationship between the cylinder volume and the gauge pressure. For example, an E cylinder can hold 622 L of gas at a filling pressure of 2200 psi. The volume-pressure cylinder factor for E cylinders equals 622 L/2200 psi, or 0.28 L/psi. (Pilbeam 39) Pilbeam, Cairo and. Mosby's Respiratory Care Equipment, 8th Edition. Mosby, 022009. <vbk:9780323051767#outline(2.4.1.9.1)>.

A hospital uses a large air compressor system to supply air through its piped gas lines. This gas will be free of pollutants found in the local environment. True or false? Why?

False. The compressor will draw air in from the local environment and therefore will contain pollutants that may contaminate the local environment.

The hospital infection control committee notifies your department that the incidence of nosocomial pneumonia in the recovery room increases significantly during the month of December. It has been suggested that the source of the pneumonia could be reusable, large-volume jet nebulizers. How would you determine whether in-use, large-volume jet nebulizers are responsible for this outbreak of pneumonia? How could you monitor the effectiveness of the sterilization of these devices?

First, determine if the device is contaminated. Microbiological identification requires that the hospital's clinical laboratory staff work with the staff of the respiratory care department to determine if infectious organisms are in the devices in question. The clinical microbiologist can provide information about nosocomial infections from direct smears and stains, cultures, serological tests, and antibiotic susceptibility testing. Ongoing surveillance is required to ensure that an infection control program is adequately protecting patients and health care providers. Surveillance typically consists of the following: equipment processing quality control, routine sampling of in-use equipment, and microbiological identification. Equipment processing is monitored with chemical and biological indicators. Routine sampling of in-use equipment can be done with sterile cotton swabs, liquid broth, and aerosol impaction. Aerosol impaction is an effective method for sampling the particulate output of nebulizers.

Know to multiply FiO2 x 5 to estimate PaO2 in a healthy adult.

For "healthy" lungs, multiply FiO2 x 5 to approximate PaO2 If true PaO2 is much less, you have a problem If true PaO2 is close, it may be time to wean the FiO2

Describe the process of fractional distillation. How effective is it?

Fractional Distillation Air is liquefied & cooled Slowly heated N & trace gases have lower boiling point Result is 99.5% pure O2 Physical Separation (Concentrators) Molecular sieves Semi-permeable plastic membrane

Which of the following statements is true regarding back pressure-compensated flowmeters? a. The needle valve is positioned before the indicator tube. b. High-resistance devices attached to these flowmeters cause erroneously high flow readings. c. Faulty valve seats do not affect flow readings. d. Gas flow from these flowmeters stops if resistance creates a back pressure that exceeds the source gas pressure.

Gas flow from these flowmeters stops if resistance creates a back pressure that exceeds the source gas pressure (Page 61)

Which conditions may benefit from hyperbaric oxygen therapy?

Gas gangrene Radiation necrosis CO/Cyanide poison Ischemic tissue transplants Necrotizing soft tissue infections Decompression sickness Refractory osteomyelitis Refractory anaerobic infections Severe acute anemia/hemmorrhage Crush injury/trauma

What is the Kinetic Theory of gases

Gases are composed of discrete molecules 1.Molecules are in random motion 2.Molecular collisions are elastic 3.Molecular activity depends on temp. 4.No physical attraction b/t molecules

According to Graham's law, which diffuses more readily into the blood, CO2 or O2?

Graham's Law Rate of gas diffusion through liquid is proportional to gas solubility & inversely to gm. mol. wt. CO2 is 19x more diffusable in blood than O2 But...Graham assumes = partial P In reality, alveolar PO2 > PCO2

Medical gas cylinders are color coded for easy identification. E cylinders of carbon dioxide are painted: a. Yellow b. Green c. Black d. Gray

Gray

What does Henry's law tell us about the diffusion of a gas into a liquid?

Henry's Law Rate of gas diffusion into liquid is proportional to partial P of gas @ given T0 Example: opening a Coke (or beer.) CO2 diffuses out of liquid into atm, where partial P of CO2 is less

What is the difference between a high-flow and a low-flow system?

High-Flow Oxygen Delivery System Delivers all of the patient's inspiratory flow needs Low-Flow Oxygen Delivery Devices Provide part of a patient's inspiratory gas flow needs

Which of the following would be considered clinical manifestations of carbon dioxide toxicity? a. Hypertension b. Bounding pulse c. PaCO2 > 70 mm Hg d. Multiple premature ventricular contractions (1) I and II only (2) II and III only (3) I, II, and III only (4) I, II, III, and IV

Hypertension, bounding pulse, PaCO2 > 70 mm Hg and multiple premature ventricular contractions (Page 83)

How is hypoxemia defined in the acute care setting vs. the home care setting?

Hypoxemia is defined in the CPGs -as a PaO2 < 60 mmHg or an SaO2 < 90% for patients in the acute care setting -as a PaO2 < 55 mmHg or SaO2 < 88% in patients breathing room air in the sub-acute or home care settings -as a PaO2 of 56-59 mmHg or an SaO2 or SpO2 < 89% in a sub-acute or home care setting in association with cor pulmonale congestive heart failure erythro-cythemia with hematocrit > 56

What is the goal of nitric oxide therapy? What is it used to treat?

Inhaled nitric oxide therapy is used to treat persistent pulmonary hypertension in newborns. Nitric oxide is highly reactive and can combine with oxygen or water to form nitrogen dioxide (NO2) or nitric acid (HNO3), respectively. Nitric oxide is delivered via the I-NOvent.

Which of the following is an indication for nitric oxide therapy? a. It has been used successfully to treat persistent pulmonary hypertension of the newborn. b. It can be used as an adjunct to the treatment of congenital cardiac defects. c. It can be used to reverse pulmonary vasoconstriction associated with adult respiratory distress syndrome. d. It can be used to treat refractory croup. (1) I and III only (2) II and IV only (3) I, II, and III only (4) I, II, III, and IV

It has been used successfully to treat persistent pulmonary hypertension of the newborn; it can be used as an adjunct to the treatment of congential cardiac defects; and it can be used to reverse pulmonary vasoconstriction associated with adult respiratory distress syndrome (Page 81)

Be able to determine duration of oxygen flow based on the weight of a liquid container.

Label: Untitled highlighter 5 "Calculating the Duration of a Liquid Oxygen Supply 1. A liter of liquid oxygen weighs 2.5 pounds, therefore: Liquid weight ÷ 2.5 = Number of liters of liquid oxygen 2. Gaseous oxygen occupies a volume that is 860 times the volume of liquid oxygen, therefore: Liters of liquid×860=Liters of gas 3. Duration of supply (minutes) = Gas supply remaining (in liters) ÷ Flow (L/min). Example How long would a liquid oxygen supply weighing 10 pounds last if a patient were receiving oxygen through a nasal cannula at 2 L/min? Amount of gass(liters)=(10 pounds ÷ 2.5 Ib/L) ×860Amount of gass = 3440 L Duration of supply(minutes)=Amount of gas ÷Flow (in liters)Duration of supply=3440 L ÷(2 L/min)Duration of supply = 1720 minutes or about 28 hours and 40 minutes" (Pilbeam) Pilbeam, Cairo and. Mosby's Respiratory Care Equipment, 8th Edition. Mosby, 022009. <vbk:9780323051767#outline(2)>.

What is the difference between turbulent flow & laminar flow?

Laminar: smooth, uniform flow; requires less energy to sustain (<2,000) Turbulent: erratic, irregular flow; requires more energy (>2000)

What is the working pressure of most respiratory care equipment?

Large medical air compressors must provide high flow (at least 100 L/min) at the standard working pressure of 50 pounds per square inch gauge (psig) for all equipment in use. (al 889) al, Kacmarek et. Egan's Fundamentals of Respiratory Care, 10th Edition. Mosby, 032012. <vbk:978-0-323-08203-7#outline(37.3.2)>.

Administration of heliox can be an effective form of therapy in which of the following situations? a. Managing postextubation stridor in pediatric trauma patients b. Providing ventilatory support for patients with severe airway obstruction resulting from chronic bronchitis and emphysema c. Administering anesthetic gases to patients with small-diameter endotracheal tubes d. Delivering oxygen therapy to asthmatic children (1) I and II only (2) I and III only (3) I, II, and III only (4) I, II, III, and IV

Managing postextubation stridor in pediatric trauma patients; providing ventilator support for patients with severe airway obstruction resulting from chronic bronchitis and emphysema; administering anesthetic gases to patients with small-diameter endotracheal tubes; and delivering oxygen therapy to asthmatic children (Page 82)

What is the minimum flow rate needed for a simple mask?

Minimum Flow Rate = 5 LPM

What is the minimum flow rate needed for a non-rebreather?

Minimum flow of 10LPM

Personal protective respirators that are used in hospital infection control programs must be certified by the National Institute of Occupational Safety and Health (NIOSH) and the U.S. Food and Drug Administration (FDA). Each type of mask typically is identified with a letter and a number code. The letter specifies whether the mask is not resistant (N), somewhat resistant (R), or strongly resistant (P) to oil degradation; the number following the letter refers to its particulate filtering efficiency. For example, an N-95 mask is not oil resistant, and it filters out 95% of the particles that attempt to flow through it.

More information about personal protective respirators can be found at the NIOSH Personal Protective Technology Laboratory Web site: http://www.cdc.gov/niosh/npptl/default.html.

Which allows for greater flows & more even pressures: single stage or multi-stage reduction valve?

Multistage regulators can control gas pressures with more precision than single-stage regulators because the pressure is reduced gradually. Additionally, multistage regulators produce gas flow that is much smoother than that from single-stage regulators. Multistage regulators are more expensive and larger than single-stage regulators, therefore they usually are reserved for tasks requiring precise gas flow (e.g., research purposes). (Pilbeam 61) Pilbeam, Cairo and. Mosby's Respiratory Care Equipment, 8th Edition. Mosby, 022009. <vbk:9780323051767#outline(3.3.1.2)>.

A respiratory therapist is helping design a new hospital wing. Which of the following agencies should be contacted so that the piping system of oxygen and air is correctly installed? a. NFPA b. FDA c. HHS d. DOT

NFPA

Know the FiO2 range for the following delivery devices: -Nasal cannula -Simple mask -Non-rebreather -Venti mask

Nasal Cannula (up to 44%) Delivers 1 to 6 LPM into anatomic reservoir Anatomic reservoir approx. 50 ml 1st 50 ml @ 100%, then air entrainment FIO2 varies w/ Vt & RR "Rule of 4's" Start w/ 20% Add 4% for every 1L of O2 Simple Oxygen Mask (35-55%) Minimum Flow Rate = 5 LPM Adds reservoir space (fills during pause) FIO2 varies w/ Vt & RR 5-12 LPM Partial Rebreathing Mask a.k.a. reservoir mask Pt. Rebreathes some exhaled gas 1st 1/3 of expiration is anatomic dead space Additional O2 fills bag during pause Up to 70% O2 Reservoir should not collapse Non-Rebreathing Mask a.k.a. reservoir mask Minimum flow of 10LPM One-way valves: b/t bag & mask (prevents rebreathing) b/t mask & RA (reduces entrainment) Up to 100% O2 (depending on flow, RR, Vt)

Which of the following statements are true regarding nitric oxide therapy? a. Nitric oxide is a potent vasoconstrictor. b. Nitric oxide is supplied in compressed-gas cylinders constructed of steel. c. Nitrogen dioxide and nitric oxide are toxic if inhaled. d. The therapeutic dose of nitric oxide is 2 to 80 ppm. (1) I and II only (2) II and III only (3) III and IV only (4) I, III, and IV only

Nitrogen dioxide and nitirc oxide are toxic if inhaled and the therapeutic dose of nitric oxide is 2 to 80 ppm. (Page 81)

PPHN

Persistent pulmonary hypertension of the newborn (PPHN) is defined as the failure of the normal circulatory transition that occurs after birth. It is a syndrome characterized by marked pulmonary hypertension that causes hypoxemia and right-to-left extrapulmonary shunting of blood.

What does Poiseuille's law tell us about decreasing the diameter of a tube by ½?

Poiseuille's Law Describes resistance (R) when flow is laminar (ΔP)(π)(r4) / 8(L)(μ) Simply stated: "as the radius of a tube is halved, resistance to flow increases by a factor of 16."

Describe the difference between a compensated & an uncompensated Thorpe tube.

Pressure-compensated flowmeters provide accurate estimates of flow, regardless of the downstream pressure. (Note that pressure-compensated flowmeters indicate actual flow unless the source gas pressure varies, the flowmeter is set to deliver a higher flow than is actually available from its source gas supply, or the float in the tube is not set in a vertical position.1) With non-pressure-compensated flowmeters (Figure 3-6), the needle valve is located before the indicator tube. Restriction or high-resistance devices attached to the outlet of a non-pressure-compensated Thorpe tube flowmeter create back pressure, which is transmitted back to the needle valve. Because the needle valve is located proximal to the Thorpe tube, the back pressure causes the float to fall to a level that indicates a flow lower than the actual flow (Pilbeam 61) Pilbeam, Cairo and. Mosby's Respiratory Care Equipment, 8th Edition. Mosby, 022009. <vbk:9780323051767#outline(3.3.2.1.1)>.

When carbogen is administered, which of the following vital signs should be monitored? a. Pulse b. Blood pressure c. Respirations d. Mental status (1) I and II only (2) I and III only (3) I, III, and IV only (4) I, II, III, and IV

Pulse, blood pressure, respirations and mental status (Page 84)

What is a regulator?

Regulators (or reducing valves) are devices that reduce high-pressure gases from cylinders or bulk storage units to lower working pressures, usually to 50 psi. Flowmeters are devices that control and indicate the gas flow delivered to patients. (Pilbeam 60) Pilbeam, Cairo and. Mosby's Respiratory Care Equipment, 8th Edition. Mosby, 022009. <vbk:9780323051767#outline(3.3)>. device that controls both pressure and flow. (Chapter 37) (al 1361) al, Kacmarek et. Egan's Fundamentals of Respiratory Care, 10th Edition. Mosby, 032012. <vbk:978-0-323-08203-7>.

Given the velocity, density, diameter, & viscosity of a gas, calculate Reynold's number.

Reynolds' Number Determines if gas flow through a tube is laminar or turbulent... Laminar: smooth, uniform flow; requires less energy to sustain (<2,000) Turbulent: erratic, irregular flow; requires more energy (>2000) Formula: R = (velocity)(density)(diameter) / (viscosity)

The RT needs to estimate how long Mrs. Jones' portable liquid O2 container will last if it contains 3 lb of liquid O2 that supplies an O2 delivery device running at 2 L/min.

Solution Step 1: Determine the amount of O2 in the cylinder. Amount of gas in cylinder=Liquid O2 weight(lb)×860 / 2.5 lb/L=3×8602.5=1032 L Step 2: Calculate the duration of the gas in the container. Duration of gas=Amount of gas in the cylinder(L)/ Flow(L/min) =1032L/ 2=516 minutes / 60(min/hr)=8 hours 36 minutes (al 895) al, Kacmarek et. Egan's Fundamentals of Respiratory Care, 10th Edition. Mosby, 032012. <vbk:978-0-323-08203-7#outline(37.4.1.7.1.2)>.

The RT needs to determine how long a G cylinder of O2 with a gauge pressure of 800 psi set to deliver 8 L/min will last until empty.

Solution Step 1: Determine the cylinder factor for an O2 G cylinder (see Table 37-4), in this case 2.41. Step 2: Apply the duration of flow equation: Duration of flow(min)=Pressure(psig)×Cylinder factor/ Flow(L/min) Duration of flow(min)=800×2.41 / 8=241 minutes(approximately 4 hours) (al 894) al, Kacmarek et. Egan's Fundamentals of Respiratory Care, 10th Edition. Mosby, 032012. <vbk:978-0-323-08203-7#outline(37.4.1.6.1.2)>.

You are asked to set up a large-volume nebulizer for the treatment of a patient with an acute asthma exacerbation. The attending physician asks you to use an 80% : 20% heliox gas mixture as the driving gas for nebulizing the β2-bronchodilator. What is the actual flow of gas being administered to the patient if the set flow on the oxygen flowmeter used is 10 L/min?

The actual flow of gas being administered to the patient receiving an 80%:20% heliox gas mixture through an O2 flowmeter at 10 L/min as the driving gas for nebulizing the beta-2 bronchodilator is actually 18 L/min = (1.8 x liter flow).

The percentage of oxygen delivery provided by molecular sieve O2 concentrators depends on which of the following factors? a. The size of the concentrator b. The rate of gas flow c. The temperature of the refrigeration unit d. The age of the sieve beds (1) II only (2) I and IV only (3) I, II, and III only (4) I, II, and IV only

The age of the sieve beds

Laboratory examination of a sputum sample from a febrile patient with a productive cough (purulent, blood-streaked sputum) reveals the presence of gram-positive diplococci and many segmented neutrophils. Suggest a possible diagnosis based on these findings.

The clinical manifestations described point to a diagnosis of pneumonia. The laboratory findings suggest a bacterial pneumonia; Streptococcus pneumoniae sp. are most commonly associated with bacterial pneumonia.

Describe an easy method of determining the number of stages in a multistage regulator.

The easiest way to determine the number of stages in a regulator is to count the number of pressure-relief valves. Each chamber should have its own pressure-relief valve. (Page 60)

What happens if the oxygen tubing connected to a Bourdon gauge becomes obstructed?

The flow rate of gas can be measured because the Bourdon flowmeter gauge is calibrated in liters per minute. As long as the pressure distal to (i.e., downstream from) the orifice remains atmospheric, the indicated flow is accurate. As resistance to flow increases, the indicated flow reading becomes inaccurate (i.e., these devices are not back pressure compensated). Figure 3-8 shows how increasing resistance at the gas outlet affects the flow reading. Note that although the outlet becomes totally occluded, the flow reading remains constant. Figure 3-9 shows a commonly used Bourdon flowmeter. (Pilbeam 62) Pilbeam, Cairo and. Mosby's Respiratory Care Equipment, 8th Edition. Mosby, 022009. <vbk:9780323051767#outline(3.3.2.2)>.

A Simple Method for Estimating the Theoretical FIO2 A 50-pound, spontaneously breathing patient is receiving oxygen at the rate of 6 L/min through a nasal cannula. The patient's tidal volume is 500 mL, and the respiratory rate is 20 breaths per minute (inspiratory time = 1 second; expiratory time = 2 seconds). Estimate the theoretical FIO2.

The flow rate of oxygen is 6 L/min or 100 mL/sec (6000mL/60 sec). If the expired gas is exhaled in the first 1.5 sec of expiration, then 0.5 sec is available for filling the anatomic reservoir, which is approximately 50 mL for this patient. The anatomic reservoir includes the nose, nasopharynx, and oropharynx, which is about one third of the patient's deadspace, or 150 mL (1 mL for every pound is a good estimate of the amount of deadspace in a normal subject). The patient's inspiration lasts 1 sec, so he will inspire 100 mL of 100% oxygen. Therefore the anatomical reservoir and the inspiratory flow deliver 150 mL of 100% oxygen to the patient. The remaining 350 mL of tidal volume will be entrained room air, which has an FIO2 of about 0.20. This 350 mL of room air contains 70 mL of 100% oxygen (350 mL × 0.20 = 70 mL). The delivered FIO2 can now be estimated: 50 mL of 100% oxygen from the anatomical reservoir 100 mL of 100% oxygen (O2 flow = 100 mL/sec) 350 mL of 21% oxygen (350 mL × 0.20 = 70 mL) 220 mL of 100% oxygen/500 mL tidal volume Estimated delivered FIO2 = 0.44.

The pressure inside a cylinder increases dramatically when the cylinder is exposed to extremely high temperatures. What prevents cylinders with frangible disks from exploding when exposed to extremely high temperatures? a. The frangible disk ruptures from the increased pressure, allowing gas to escape from the cylinder. b. The cylinder stem blows off when the temperature reaches 200° F. c. The stem diaphragm ruptures, allowing gas to escape. d. The frangible disk melts when the temperature reaches 100° F.

The frangible disk ruptures from the increased pressure, allowing gas to escape from the cylinder.

Estimating Duration of Liquid Oxygen Cylinder Gas Flow

The only accurate method for determining the volume of gas in a liquid-filled cylinder is by weight. Because 1 L of liquid O2 weighs 2.5 lb and produces 860 L of O2 in its gaseous state, the amount of gas in a liquid O2 cylinder can be calculated with the following formula: Amount of gas in cylinder=Liquid O2 weight(lb)×860 / 2.5 lb/L After the amount of O2 remaining in the cylinder is determined, the duration of the gas in minutes can be calculated with the following formula: Duration of gas(min)=Amount of gas in cylinder(L) / Flow(L/min) As with gaseous O2 cylinders, a wide margin of safety is needed for estimation of cylinder duration. This margin of safety varies with the size of the portable O2 unit or large storage container. (al 894-895) al, Kacmarek et. Egan's Fundamentals of Respiratory Care, 10th Edition. Mosby, 032012. <vbk:978-0-323-08203-7#outline(37.4.1.7)>.

Define mild, moderate, & severe hypoxemia.

The oxygenation status is determined by examination of the PaO2, arterial O2 saturation (SaO2), and arterial O2 content (CaO2) The PaO2 represents the partial pressure of O2 in the plasma of the arterial blood and is the result of gas exchange between the lung and blood. The PaO2 is reduced in various settings but most often when lung disease is present. PaO2 of less than 40 mm Hg is called severe hypoxemia, PaO2 of 40 to 59 mm Hg is called moderate hypoxemia, PaO2 of 60 mm Hg to the predicted normal is called mild hypoxemia. (al 388) al, Kacmarek et. Egan's Fundamentals of Respiratory Care, 10th Edition. Mosby, 032012. <vbk:978-0-323-08203-7#outline(18.6.1.1.6)>. From the powerPt slides Zimmerman has Normal SpO2 ranges 95%-99% 40/50/60----70/80/90 Rule Mild hypoxemia = PaO2 of 60 - 79 mmHg Moderate hypoxemia = PaO2 of 40 - 59 mmHg Severe hypoxemia = PaO2 of 39 mmHg or less

A respiratory therapist is having trouble attaching a regulator to an E cylinder. One possible cause might be: a. The outlet threads of the cylinder do not match the threads of the regulator. b. The regulator diaphragm is jammed. c. The pin positions of the regulator are not the same as those on the cylinder. d. The cylinder has not been cracked.

The pin positions of the regulator are not the same as those on the cylinder.

A respiratory therapist is checking cylinder markings to determine whether any of the cylinders need to be tested. The labeling reads as follows: 9 83 + 6 94 + This information indicates: a. The cylinder is due for retesting. b. The time between the test dates shown exceeds recommendations. c. The cylinder is made of aluminum. d. The owner of the cylinder.

The time between the test dates shown exceeds recommendations.

A respiratory therapist "cracks" an H cylinder of oxygen and then attaches an oxygen regulator to the cylinder outlet. She slowly opens the valve stem and hears a sudden, loud hissing sound coming from the connection between the cylinder outlet and the regulator. What should she do?

There is an apparent leak at the connection. The valve stem should first be closed, then the connection between the cylinder outlet and the regulator tightened

A home care patient who requires continuous oxygen therapy is instructed to use a nasal cannula at a flow of 2 L/min. After a short period, the patient is admitted to the hospital with signs of hypoxemia. When asked if he had been using the prescribed oxygen, the patient explains that he used it only intermittently because it was uncomfortable, and furthermore he felt self-conscious about wearing the equipment in public. What would you suggest to help this patient overcome the problems he described?

These are common complaints of patients who use nasal cannulas for long-term oxygen therapy. You could suggest that he consider using a transtracheal oxygen (TTO) device. These devices are more comfortable for patients requiring long-term oxygen therapy and are generally well tolerated by patients. Just as important, they are cosmetically more pleasing to most patients than are nasal cannulas. If the patient agrees to try the TTO device, you must teach him how to properly care for it. Adequate education is an essential part of ensuring patient compliance with any type of long-term oxygen therapy device.

What 2 pressure relief devices are typically incorporated into cylinder valve construction?

These relief valves are of three basic designs: frangible disk, fusible plug, and spring-loaded. The frangible metal disk ruptures at a specific pressure. The fusible plug melts at a specific temperature. The spring-loaded valve opens and vents gas at a set high pressure. In each case, the activated valve vents gas from the cylinder and prevents pressure from becoming too high. Most small cylinders have a fusible plug relief valve. Most large cylinders have a spring-loaded relief valve. These safety relief valves are always located in the cylinder valve stems. (al 892) al, Kacmarek et. Egan's Fundamentals of Respiratory Care, 10th Edition. Mosby, 032012. <vbk:978-0-323-08203-7#outline(37.4.1.3)>.

Which of the following are advantages of using TTO therapy catheters? a. They do not require periodic replacement. b. The incidence of infection is considerably lower than with other low-flow oxygen devices. c. They require lower oxygen flows to achieve a given FIO2 than do standard nasal cannulas. d. They are less obtrusive (i.e., more cosmetically pleasing) than nasal cannulas. (1) I and III only (2) II and III only (3) III and IV only (4) II, III, and IV only

They require lower oxygen flow to achieve a given F1O2 than do standard nasal cannulas and they are less obtrusive than nasal cannulas (page 70)

Before using an H cylinder of oxygen, a respiratory therapist opens it, and gas at high pressure comes out of the cylinder outlet. Which of the following statements is true? a. This was an accident and should not be repeated. b. Allowing gas to escape from the cylinder lets the therapist smell the gas to ensure that it is oxygen. c. This action clears debris from the connector. d. This action should be performed after a regulator is attached to the cylinder outlet.

This action clears debris from the connector.

What are the physiologic effects of hyperbaric oxygen therapy?

Trapped Gas Bubbles, When Exposed to the Increased Pressure during Hyperbaric Treatment, Will Decrease in Size (Boyle's Law) Supersaturation of Plasma with Oxygen Up to 1500 mmHg Improved O2 transport Increased Elimination of Other Gases N, CO Increased Ability of White Blood Cells to Fight Infections Neovascularization to Poorly Perfused Tissues Lethal to anaerobic microorganism

A fire breaks out on the north wing of the fifth floor of the hospital where you work. How should you respond to this emergency?

Turn off the zone valve that controls oxygen flow from the main oxygen supply to the affected area (in this case, the fifth floor of the north wing). Call for assistance to provide E cylinders of oxygen for patients requiring oxygen therapy.

How do oxygen concentrators function? Which type is most effective?

Two types of concentrators are currently available: those using semipermeable plastic membranes and those using molecular sieves. Concentrators using semipermeable membranes to separate oxygen from room air are composed of plastic membranes containing pores that are 1 mm in diameter (1 mm = 1/25,000 in). Atmospheric gases diffuse through the membrane at different rates. The rate at which a gas diffuses depends on its diffusion constant and solubility for the plastic membrane and the pressure gradient for the gas across the membrane. A diaphragm compressor is used to provide a constant vacuum across the membrane. Oxygen and water vapor diffuse through these membranes faster than nitrogen. Generally, a constant flow of humidified 40% oxygen can be provided at a flow of 1 to 10 L/min.16 Figure 2-23 is a functional diagram of an oxygen concentrator that uses a semipermeable membrane. Figure 2-24 shows a typical oxygen concentrator that relies on molecular sieves to produce an enriched oxygen mixture. Such systems use a compressor to pump room air at pressures of 15 to 25 psig to one of two sets of sieves. Nitrogen is removed by passing room air through sodium-aluminum silicate (zeolite) pellets, producing an enriched oxygen mixture. It is important to mention that nitrogen and other gases absorbed by the zeolite pellets must be purged to ensure that the unit functions properly. In the pressure swing adsorption (PSA) method, intermittent pressurization of one of the sieve beds occurs while the other bed is purged to remove any absorbed gases and moisture. typical compact oxygen concentrator (Vision Aire) used for home care treatment of patients requiring long-term oxygen therapy. The NewLife oxygen concentrator (AirSep Corp., Buffalo, New York) shown is equipped with alarms that signal power failure, high and low pressure, and low oxygen concentration. At just 30 lbs and providing nearly silent operation at 40 decibels, the industry's most compact in-home oxygen concentrator is also the most power efficient at 290 watts. (Pilbeam 48) Pilbeam, Cairo and. Mosby's Respiratory Care Equipment, 8th Edition. Mosby, 022009. <vbk:9780323051767#outline(2.4.7)>.

Estimate the concentration of gas delivered to an adult patient via nasal cannula.

Use Formula (Cs x Vs) + (Cent x Vent) = (Cdel x Vdel) or use the one given below as an example. outcome is still the same using either step. Find O2 %, Air & O2 flow given What is the O2 % when mixing 6L of O2 & 6L of Air? O2% = (Air flow x 20) + (O2 flow x 100) / Total Flow = (6 x 20) + (6 x 100) / 12 = (120) + (600) / 12 =60%

What is the normal range of V/Q matching? (Hint: 0.8-1.2)

Ventilation/Perfusion ratio (0.8) ~4L/min ventilation ~5L/min perfusion

What are the principles of viscous shearing & vorticity?

Viscous shearing: a high-velocity jet injected into a quiescent (stationary) gas Vorticity: tendency of velocity of jet gas to decrease due to "swirling" mixture of 2 gases

You are the therapist on call when an asthmatic patient is admitted to the emergency department of the hospital. The attending physician requests that you administer heliox containing 30% oxygen to the patient. While you are administering the gas from a cylinder labeled 70% : 30% (helium : oxygen), the patient becomes progressively more dyspneic and cyanotic. What should you do?

You should remove the helium-oxygen mixture, switch the patient to 100% oxygen (i.e., non-rebreathing mask), and immediately notify the physician of the patient's condition. You should recheck the concentration of oxygen delivered from the cylinder. It is possible that the contents of the cylinder were "unmixed," and thus the FIO2 delivered to the patient was actually much less than expected.

What is alveolar deadspace?

alveoli that are ventilated but are not perfused. The condition may exist when pulmonary circulation is obstructed, as by a thromboembolus. (Chapter 10) (al 1341) al, Kacmarek et. Egan's Fundamentals of Respiratory Care, 10th Edition. Mosby, 032012. <vbk:978-0-323-08203-7>.

Define hypoxemia.

an abnormal deficiency in the concentration of oxygen in arterial blood. Symptoms of acute hypoxemia are cyanosis, restlessness, stupor, coma, Cheyne-Stokes respiration, apnea, increased blood pressure, tachycardia, and an initial increase in cardiac output that later falls, producing hypotension and ventricular fibrillation or asystole. Chronic hypoxemia stimulates red blood cell production by the bone marrow, leading to secondary polycythemia. Hypoxemia caused by decreased alveolar oxygen tension or underventilation improves with oxygen therapy. Hypoxemia resulting from shunting of blood from the right side of the heart to the left side without exchange of gases in the lungs is treated with bronchial hygiene and positive end-expiratory pressure. Also spelled hypoxaemia. ( Mosby 925) Mosby. Mosby's Dictionary of Medicine, Nursing & Health Professions, 8th Edition. Mosby, 122008. <vbk:978-0-323-04937-5#outline(8)>. (Zimmerman PPT Slide) Hypoxemia is defined in the CPGs as a PaO2 < 60 mmHg or an SaO2 < 90% for patients in the acute care setting as a PaO2 < 55 mmHg or SaO2 < 88% in patients breathing room air in the sub-acute or home care settings

What is the goal of hyperbaric oxygen therapy?

exposure of a patient or patients to a pressure greater than one atmosphere absolute while breathing 100% oxygen either continuously or intermittently

You are asked to administer a helium-oxygen mixture to an asthmatic patient who is admitted to the emergency department with acute respiratory distress. Which of the following devices is the most appropriate method of delivering this form of medical gas therapy? a. air entrainment mask b. partial rebreathing mask c. nasal cannula d. nonrebreathing mask

nonrebreathing mask (Page 83)

Oxygen

standard temperature, pressure, and dry (STPD), O2 has a density of 1.429 g/L, being slightly heavier than air (1.29 g/L). O2 is not very soluble in water. At room temperature and 1 atm pressure, only 3.3 ml of O2 dissolves in 100 ml of water. (al 888) al, Kacmarek et. Egan's Fundamentals of Respiratory Care, 10th Edition. Mosby, 032012. <vbk:978-0-323-08203-7#outline(37.3.1.1)>.