Section 2.pdf

Section 2 Medical Gas Therapy Equipment  Indications for Oxygen Therapy 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...

Section 2 Medical Gas Therapy Equipment  Indications for Oxygen Therapy 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 2 Indications for Oxygen Therapy (continued) – 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 3  High- and Low-Flow Oxygen Delivery Systems 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 4  Positive Pressure Grossly exceeds inspiratory demand Interface creates a seal FLOW High Flow Meets and exceeds inspiratory demand NO air entrainment at interface Low Flow Does not meet inspiratory demand Air entrainment at interface 5  Positive Pressure FiO2 is set Seal does not allow entrainment FLOW High Flow FiO2 is set* *If flow still exceeds pt demand, no entrainment = Low Flow guaranteed FiO2 at alveoli FiO2 is an estimation Higher MV -> More entrainment -> Lower FiO2 at alveoli 6  Positive Pressure Anesthesia bag Self inflating bag CPAP/BiPAP Ventilators FLOW High Flow Venturi Mask Low Flow Nasal Cannulas Simple mask Partial rebreather Nonrebreather HiOx 7 Low-Flow Oxygen Delivery Devices Nasal Cannula/Nasal Catheter Reservoir Cannula/Pendant Cannula Transtracheal Catheter Simple Oxygen Mask Partial Rebreathing/Non-Rebreathing Masks HiOx80 Disposable High FIO2 Oxygen Mask Vapotherm 2000i 8  Low-Flow Oxygen Delivery Devices 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 O 2 9 10 Nasal Cannula 11 Nasal Cannula 12  Low-Flow Oxygen Delivery Devices Nasal catheter – Similar to NC, but slightly more invasive – Passes through nose & turbinates to rest in oropharynx @ level of uvula 13 Nasal Catheter 14  Low-Flow Oxygen Delivery Devices Reservoir Cannula/Pendant Cannula – Goal: maintiain FIO2 @ lower flow – Provides a small reservoir (to be used in addition to anatomical) 15 Pendant Cannula 16 Reservoir Cannula 17  Low-Flow Oxygen Delivery Devices Transtracheal Catheter – Continuous, long-term O2 – Surgically inserted into trachea @ 2nd cartilage ring – Uses less flow than a NC (59% less) – Hazards: Infection subQ emphysema hemoptysis 18 Transtracheal Catheter 19 Transtracheal Catheter 20  Low-Flow Oxygen Delivery Devices Simple Oxygen Mask (35-55%) – Minimum Flow Rate = 5 LPM – Adds reservoir space (fills during pause) – FIO2 varies w/ Vt & RR – 5-12 LPM 21 Simple O2 Mask 22 Simple O2 Mask 23  Low-Flow Oxygen Delivery Devices 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 24  Low-Flow Oxygen Delivery Devices 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) 25 Partial Rebreathing Mask 26 Non-Rebreathing Mask 27  Low-Flow Oxygen Delivery Devices HiOx80 Disposable High FIO2 Oxygen Mask – Designed for FIO2 w/ less entrainment – No entrainment ports – Better seal – 750ml reservoir – Up to 80% O2 @ only 8 LPM 28 HiOx80 Disposable 29  High-Flow Nasal Cannulas High-flow nasal cannula (HFNC) systems – Can achieve high FIO2 levels – Washes out CO2 from the nasopharyngeal dead space – Generates gas flows that exceed the inspiratory flow needs of most patients. – Include a patient interface, a gas delivery device to control oxygen flow, and a humidifier. Increased flow means we need to humidify for our patients! 30  Vapotherm – 5 to 40 LPM @ up to 99% relative humidity – Vapor transfer cartridge (0.01 microns) – Rain-out is minimized – Up to 40 LPM via NC, 20 LPM via transtracheal catheter 31 Vapotherm Precision Flow 32 Vapotherm Cartridge 33 Fischer & Paykel AIRVO 2 34 Fischer & Paykel OptiFlow 35  High-Flow Oxygen Delivery Systems Venturi or HAFOE Mask 36  Venturi/HAFOE Mask Jet cleaves RA & uses viscous shearing to entrain Ratio of air entrainment to O2 flow: L of air entrained = 1.0-FIO2 L of O2 FIO2-0.21 (FIO2 = desired concentration) 37 38  Let’s Do the Math A patient is ordered a 40% venti mask. She is breathing @ a rate of 18 bpm w/ a minute volume of 8L & an I:E ratio of 1:2. Is the device providing adequate flow if the flowmeter is set @ 8LPM? 39  Entrainment Ratios Oxygen Percentage Air:O2 Ratio Total Parts 100 0:1 1 70 0.6:1 1.6 60 1:1 2 50 1.7:1 2.7 40 3:1 4 35 5:1 6 30 8:1 9 28 10:1 11 24 25:1 26 40 Cool Mist Aerosol w/ Venturi Helps reduce swelling by promoting vasoconstriction of blood vessels 41  High-Flow Oxygen Delivery Systems Anesthesia Bag-Mask Systems – a.k.a. “flow-inflating bag” (vs. self-inflating) – Drawbacks: Cannot bag sans gas source – Benefits: 100% FiO2 Can “feel” lung compliance 42 Flow Inflating Bag 43  Oxygen Enclosures or Environmental Devices Incubator Head Box or Oxyhood Mist Tents 44  Oxygen Enclosures or Environmental Devices Incubator – Controls infant environmental T0 & FIO2 – Frequent hands-on care reduces efficiency of O2 regulation 45 Incubator 46 Infant Temperature Regulation Brown Fat White Fat 47  Oxygen Enclosures or Environmental Devices Head Box or Oxyhood – Encloses infant’s head – Flow adjusted to prevent entrainment – Gas is premixed (blender), heated, humidified – Often used w/ incubator – Must analyze O2 near head! Variations in O2 concentration may occur Layering 48 49 Gas Densities O2: 1.429 g/L Air: 1.29 g/L CO2: 1.98 g/L He: 0.1785 g/L N2O: 1.98 g/L NO: 1.34 g/L What do gas densities tell us about the layering effect? O2 Analyzation 51 Head Box 52  Oxygen Enclosures or Environmental Devices Mist Tents – a.k.a. “croupettes” – Primarily used for aerosol therapy – FIO2 may be somewhat controlled Nursing care Difficult to seal 53 Croupette for infants 54  Hyperbaric Oxygen Therapy Definition – defined by the Undersea Hyperbaric Medical Society (UHMS) – exposure of a patient or patients to a pressure greater than one atmosphere absolute while breathing 100% oxygen either continuously or intermittently – https://www.youtube.com/watch?v=1wrLfZ4jI O0 55 Physiological 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 56  Conditions That May Benefit 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 57  Physiological Effects of Hyperbaric Oxygen Therapy (continued) Increased Ability of White Blood Cells to Fight Infections Neovascularization to Poorly Perfused Tissues Lethal to anaerobic microorganism 58 Equipment for Hyperbaric Oxygen Therapy Monoplace Chamber – 1 pt. @ a time – Typically pressurized w/ O2 Multiplace Chamber – More than 1 pt. @ a time – Pressurized w/ RA, O2 via NRB, etc. – Healthcare provider may accompany pt. 59 Monoplace Hyperbaric Chamber 60 Multiplace Chamber 61 Multiplace Chamber 62  He/O2 Therapy Helium–oxygen (heliox) Low density of gas improves ability of gas to move around obstruction. Clinical application – Exacerbation of asthma – Treatment of postextubation stridor – Treatment of refractory croup – Treatment of severe airway obstruction in chronic bronchitis and emphysema 63  Helium–Oxygen Therapy (Cont.) Available concentrations – 80% Helium and 20% oxygen – 70% Helium and 30% oxygen – 60% Helium and 40% oxygen 64  Helium–Oxygen Therapy (Cont.) Can be administered through an endotracheal tube or well-fitted nonrebreather. Actual flow: due to low density of gas oxygen flowmeters are not accurate. Correction factors used to determine actual flow rate of gas: – 80:20—1.8 × liter flow – 70:30—1.6 × liter flow – 60:40—1.4 × liter flow 65 66  Carbon Dioxide/Oxygen Therapy CO2/O2 therapy has been used for many years for the treatment of various disorders (ex: singultus). Gas mixtures are available in 5/95% and 7/93% carbon dioxide–to-oxygen mixtures. 67  Nitric Oxide (NO) Therapy 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. 68  Nitric Oxide (NO) Therapy Dangers: – NO2 – Rebound vasoconstriction (Don’t wean too fast!) Method of action: – Short-acting – Delivered directly to lung 69 I-Novent 70