Oxygen Therapy Part 1&2 powerpoint – Flashcards

Gas therapy

medical treatment

drugs

assess need for therapy, recommend & administer dosage, determine goals of therapy, monitor response, alter therapy accordingly, & record their data in the pt record (chart)

< normal Oxygen levels at the tissue level

< normal Oxygen levels in the blood

1.Correcting and Relieve Hypoxemia 2.Decreasing Symptoms of Hypoxemia 3.Decrease the Work of Breathing (WOB)

by raising alveolar and blood levels of oxygen. (easiest to attain and measure)

1.peripheral vasodilatation ( pt feels warm) 2. pulmonary vasoconstriction (shunting in lung, increased pulmonary vascular resistance) 3. tachycardia (primary indication of hypoxemia)

the heart. (tachycardia)

1. decrease the work of breathing (asthma, COPD-more secretions) 2. decrease the work of the heart (myocardial infarction, pulmonary edema)

supplemental oxygen ( lessens dyspnea and WOB, improves mental function)

Supplemental O2 can relieve hypoxemia & relieve pulmonary vasoconstriction & hypertension, reducing right ventricular workload

1. Increasing ventilation to get more O2 in the lungs & to the Blood (Increased WOB), 2. Increasing Cardiac Output to get more oxygenated blood to tissues (Hard on the heart, especially if diseased) 3. Hypoxia causes Pulmonary Vasoconstriction & Pulmonary Hypertension- These cause an increased workload on the right side of heart (Over time the right heart will become more muscular & then eventually fail (Cor Pulmonale))

stroke volume x heart rate

tidal volume x respiratory rate

Cerebral hypoxia causes the patient to be: Confused, Lethargic, Agitated, Disoriented. With oxygen therapy and relief of tissue hypoxia, the therapist can expect a clearer sensorium or a more alert patient.

positive expiratory-end pressure

1. Tachycardia 2. Dyspnea 3. Cyanosis(unlessanemiaispresent) 4. Impairment of special senses 5. Headache 6. Mental disturbance 7. Slight hyperventilation (tachypnea)

absorption atelectasis, reduced mucocilliary activity, fire hazard, neonatal retinopathy of prematurity, oxygen induced hypoventilation, oxygen toxicity

high oxygen concentrations in the lung can wash out nitrogen in the lung and reduce production of surfactant, which may lead to atelectasis. rapid changes in FiO2 will cause atelectasis to form, therefore, change FiO2 gradually in 5-10 percent increments. maintain FiO2 below 0.60

the beating of the cilia in the mucocilliary blanket is not as active when high FiO2s are used. maintain FiO2 below 0.60

oxygen supports combustion causing a fire to burn hotter and more rapidly

blindness occurring in premature infants and newborns as a result of high PaO2, not high FiO2. It is more common in premature infants, maintain PaO2 below 80 mmhg. normal levels of PaO2 in infants is 50-70 mmhg.

Respiratory depression is a complication of oxygen therapy in the patient who breathes on a hypoxic drive (COPD) Signs: a) Decreased respiratory rate (RR) and tidal volume (VT) b) ↑ PaO2, ↑ PaCO2, ↓ pH c) Patient sensorium - lethargic, sleepy, confused 2. Treatment: a) Decrease level of inspired oxygen b) Maintain PaO2 between 50 and 65 mm Hg for these patients c) Do not place on ventilator because of hypercarbia

High O2 concentrations result in increased O2 free radicals and therefore lung tissue toxicity, This may lead to adult respiratory distress syndrome (ARDS). Patients at risk when they receive high FIO2 (> 60%) for periods of 12 - 24 hours. Maintain FIO2 below 0.60. Signs and Symptoms: a) Nausea and vomiting b) Substernal chest pain and tightness c) Refractory hypoxemia d) Tachypnea e) Decreased surfactant production f) Decreased compliance g) Pulmonary edema. Remember that oxygen is a drug and should never be used indiscriminately.

1. Hypoxemic hypoxia 2. Anemic hypoxia 3.Stagnant(circulatory)hypoxia 4. Histotoxic hypoxia

hypoxemic hypoxia (pneumonia)

high oxygen concentrations result in high oxygen free radicals

A. Caused by a lack of O2 in the blood as a result of: 1. Inadequate O2 in the inspired air (Administering O2 is beneficial) 2.Alveolar hypoventilation (Administering O2 alone may not be beneficial) 3.Diffusion defects (pulmonary edema, atelectasis, and pulmonary fibrosis) (Administering O2 alone may not be beneficial ) 4. A ventilation/perfusion mismatch (Administering O2 may be beneficial) 5. An anatomic right to left shunt (Administering O2 is not beneficial) B. If a normal PaO2 level cannot be maintained with a 60% O2 mask, a large shunt is probable and should not be treated with higher O2 concentrations. Continuous positive airway pressure (CPAP) should be administered provided that the PaCO2 is at normal or below normal levels. If the PaCO2 level is elevated in a patient with hypoxemia, mechanical ventilation should be initiated.

The blood's capacity to carry O2 is reduced as a result of: 1) A decreased hemoglobin (Hb) level-- a) Normal Hb level is 12 to 16 g/dL of blood. b) The PaO2 level may be normal, but because of the blood's reduced capacity to carry O2, the tissues may be deprived of O2. The Hb value must be determined to assess the patient's oxygenation status. c) The Hb content may be increased by administering packed red blood cells (RBCs). 2) Carbon monoxide (CO) poisoning: a) CO affinity for Hb is 200 to 250 times faster than O2 and therefore occupies the iron-binding sites on Hb before O2 can. This causes tissue hypoxia. b) Because Hb releases the CO more readily when levels of PaO2 are high, the patient should immediately be given 100% oxygen, usually via a non-rebreathing mask, which delivers high O2 concentrations. c) Elevating the PaO2 even higher to further increase the dissociation of Hb from CO may be achieved with hyperbaric O2 therapy. d) Patients who have been involved in fires or who have been breathing care fumes must be treated immediately for CO poisoning. e) PaO2 and Hb saturation (SaO2) readings may be within a normal range even though the patient has severe hypoxia. f) The level of CO bound to Hb (carboxyhemoglobin) may be determined with CO oximetry or hemoximeter. g) The patient usually presents with a normal PaO2 level and a low or normal PaCO2 level. The pH level is usually low as a result of lactic acidosis (metabolic acidosis), caused by severe hypoxia. Lactic acid is produced as the body goes into anaerobic metabolism trying to provide more oxygen to the tissues. 3) Excessive blood loss also may result in anemic hypoxia. Administering blood (RBCs) is the appropriate treatment. 4) Methemoglobin may cause anemic hypoxia and is most commonly a result of nitrite poisoning. Treat by administering ascorbic acid or methylene blue, which removes the chemical (nitrite) from the system. 5) Iron deficiency leads to anemia and is treated by increasing iron intake and administering blood.

The O2 content and carrying capacity is normal but capillary perfusion is diminished as a result of: 1) Decreased heart rate. 2) Decreased cardiac output. 3) Shock. 4) Embolism. May be seen as a localized problem, such as peripheral cyanosis resulting from exposure to cold weather.

The oxidative enzyme mechanism of the cell is impaired as a result of: 1) Cyanide poisoning 2) Alcohol poisoning. Rarely accompanied by hypoxemia but is accompanied by increased venous PO2 levels.

Delivered v. Inspired

3 basic ways: 1. Laboratory measures - invasive or noninvasive 2. Clinical Problem or condition 3. Symptoms of hypoxemia

invasive or noninvasive : 1. PO2 - partial pressure of oxygen. PAO2 - Partial Pressure of Oxygen in Alveoli. PaO2 - Partial pressure of Oxygen in arterial blood. 2. Hgb Saturation. SaO2 - Arterial Saturation of Oxyhemoglobin. SpO2 - Pulse Oximetry of Oxyhemoglobin Saturation

Specific clinical problems or conditions that where hypoxemia is common: Post op, COPD, PE, Etc.

Respiratory, Cardiovascular, & Neurological: Tachycardia,Tachypnea,hypertension,cyanosis,dyspnea, disorientation, clubbing, etc.

Low = 60%

Dependent on provided flow & Pt demand: Fixed- FIO2 does not vary. Variable- FIO2 varies when pt changes

Flow does not meet Inspiratory demand. O2 is diluted with air on inspiration: Nasal Cannula, Nasal Catheter, Transtracheal Catheter, Reservoir Cannulas - Mustache, Pendant

High flow systems supply the patient's entire inspired volume. Low flow systems will only supply part of the patient's inspired volume

1) Tidal volume: 300 - 700 ml 2) Respiratory rate: < 25 breaths/min. 3) Regular ventilatory pattern

1. Physician order 2. Oxygen humidifier 3. No Smoking Sign 4. Oxygen source and flowmeter 5. Item not needed is an oxygen analyzer

1-6 L/m, > 4L requires Humidity. Can cause irritation, dryness, bleeding, etc., Rule of thumb Nasal: ( With normal rate/depth ) • To estimateFIO2: FIO2 increases by 4 % for every 1 L/min. [4 X (L/M)] + 20 = ~FiO2. Delivered FIO2: 0.24 - 0.44 Most appropriate initial oxygen device for COPD patients with stable respiratory rate and tidal volumes.

Visualize placement or blind to depth = to length of nose to tragus. Replace Q8hrs. Affects secretion, irritation, etc. Good for short procedures •(bronchoscopy)

Surgically inserted in trachea. Uses trachea/upper airway as reservoir. Requires very low flows to meet needs

FiO2 varies with amount of air dilution, pt dependent. Must assess response to therapy. Rule of thumb Nasal Cannula: With normal rate/depth • [4 X (L/M)] + 20 = ~FiO2

Obstruction, Displacement, Irritation

Builds O2 supply in reservoir between breaths. Reduces air dilution. Reduces O2 use, increased utilization - Provides higher FIO2 @ lower flows

Frequent replacement. No humidification. Requires nasal exhalation: At low flows, to reopen reservoir. 1. Nasal- Stores ~20ml, Aesthetically displeasing. 2. Pendant- Better aesthetically, Extra weight can irritate ears/face

Simple Mask, Non-Rebreather, Partial Non-Rebreather, Non-rebreathing reservoir circuit

Gas gathers in mask. 100-200ml. Exhalation ports. Air entrained thru ports & around mask. Flow: 6-10 L/M. Delivered FIO2: 0.40 - 0.55. Flow must be at least 6 L/min. to flush out exhaled CO2.

Utilizes 1L reservoir bag & mask. Has no one-way flap valves. 1st third (dead space) is breathed into reservoir bag & rebreathed. Air entrainment from ports & around mask. Adequate flow as long as reservoir bag does not collapse on inspiration (Flow: 6 - 10 L/min) - Delivered FIO2: 0.60 - 0.65

Utilizes one-way flap valves • between reservoir & mask, on one exhalation port. Leak free will provide 100% • >~70% FIO2 is rare. Hard to provide leak free system. Used to deliver 100% O2 in an emergency such as Pneumothorax, CO Poisoning, CHF, Burns, MI, etc. Used for mixed gas therapy (He/O2 mixtures, CO2/O2 mixtures)

Flow rates must be sufficient to keep the bag from collapsing. If bag collapses, increase the flow. If patient inhales and bag does not slightly contract: - Mask is not tight, seal mask, Nonrebreathing valve is stuck, replace mask

Principal Same as mask system Reservoir. Can be piece of blue tubing or res bag - Can be used with T piece on Trach/ETT, Aerosol Mask. Utilizes fail safe inlet valve

Irritation, Obstruction, Dislodgement (needs to be monitored)

The pts breathing pattern and blood gas values.

exceeds

Supplies given FIO2 @ flows higher than inspiratory demand. Uses entrainment or blenders

3 X Minute Ventilation

f x VT (how many breaths in a minute)

20 L/m is at the upper end

60 L/m

Amount of air entrained varies directly with port size & velocity.

Higher flow, Lower FIO2

Air to Oxygen ratio (amount of air entrained). Downstream resistance (back pressure). Increased resistance: decreases entrainment, Decreases total flow, Increased FIO2

insufficient flow for inspiratory demand

nominal effect on FIO2. Ratio remains true at varying input flows - changes total flow

Air Entrainment Mask (AEM)/(Venti-Mask), Air Entrainment (AE) Nebulizer (Large Volume Nebulizer) -cool/heated aerosol

Adjustable air entrainment ports & jets to precisely control FIO2 & flow. Higher the flow, lower the FIO2- (inverse relationship) vice versa. For precise FIO2's, total flow must be > Inspiratory Demand (peak Inspiratory flow) (3 X minute ventilation)

Allows connection of a humidified gas to the entrainment port

Delivers precise FIO2 concentrations - Ideal for patient with COPD. Ideal for patients with irregular tidal volumes, respiratory rates and breathing patterns. Patient may use nasal cannula during meals

1.The FIO2 remains the same with increases or decreases in the flow through the oxygen inlet. 2.The FIO2 will increase: a) As the internal diameter of the gas injector increases b) With increased resistance or obstruction downstream. 3.The FIO2 decreases as the size of the air entrainment ports are increased. 4.Total flow increases as the size of the air entrainment ports are increased.

Flowmeter setting x Factor

1) Air/O2 entrainment ratio is 10:1 for 28%. 2) The total flow factor is 11 (10 + 1 = 11). 3) The total flow from the nebulizer is equal to the flowmeter setting times the flow factor(O2 Flow x Factor = Total Flow) 5 LPM x 11 = 55 L/min total flow

Same as mask except: Additional Temp & Humidity control, Allows for administration of particulate water (sterile) to airway:: Great for trach's (heated), Airway edema (cool), Have fixed jets, port is only variable » Limits O2 flow to 12-15 l/m. Provide fixed FIO2 only when total flow exceeds Insp Demand » Face tents provide less consistent FIO2.

Visual inspection, Aerosol Mist is seen exiting tubing on Insp & flow is constant, Pt Vt compared to nebulizer flow.

Delivered FIO2: 0.21 - 1.0, and depends upon the aerosol source. Reservoir tubing should be utilized to maintain the appropriate FIO2. If reservoir is removed, FIO2 will decrease due to entrained room air. Should see aerosol from reservoir tubing during inspiration

1) Increase the flow. 2) Add more reservoir tubing. 3) Set up a device to provide more flow (blender, tandem set-up, change flowmeter, etc.)

Delivered FIO2: 0.21 - 1.0, and depends upon the aerosol source and nebulizer. Room air will not enter device's exhalation ports as long as the device's flow exceeds the patient's inspiratory flow (>40 L/min)

Affected by downstream resistance, Water in tubing, Obstruction

@100% a large volume nebulizer (LVN) can only provide 12-15L/M. To be a true High Flow device it must ensure constant FIO2 by providing full inspiratory demand.

Add reservoir tubing if intubated or trached. Closed reservoir - 3-5L anesthesia bag with emergency inlet valve. Shotgun- Dual LVN's Most common, Lower entrainment- decrease FIO2, increase flow, Add supplemental O2 to mask

Downs Flow» 30-100% O2. Up to 100 L/M. Does not utilize humidity

Downstream Pressure from the entrainment port, Increases Back Pressure, Decreases entrainment - Increases FIO2- Decreases Flow, Results in variably delivered FIO2 - Not enough flow to meet inspiratory demand

Enclosures: - Tents - Hoods - Incubators. Others: - Bag-valve-mask (BVM) - Pulse Dose Cannula - Concentrators

Rare. Provides: Humidity, Temperature, FIO2, & Filtering - Frequent opening & constant leakage. Make FIO2 variable. Analyze FIO2 @ patient head level (layering) - Primarily for pediatric aerosol therapy for Croup or CF

Best method to deliver controlled O2 to infants - Covers only head. Ideal to allow nursing access - 7-10 L/m minimum flow to prevent CO2 buildup. To flush adequately - Flows above 10-15 L/M are contraindicated. Generate damaging noises, cold, & dry. Cold stress can increase O2 consumption & apnea - Analyze FIO2 @ pt head level (layering). Must heat & humidify incoming gas. Do not direct at patient face. Maintain Neutral Thermal Environment. Age & weight appropriate

Plexiglas enclosure. Servo controlled convex heating with supplemental O2. Frequent opening & dilution makes it hard to deliver high O2. Hoods are used in incubators to provide supplemental O2

Used when entrainment cannot provide high enough FIO2 @ High flows. Need frequent analyzing for safety. Methods: Manual mixers, Blenders

1. Mixing gas manually - Individual Air & O2 flow meters combined for a desired FIO2 & Flow. 2. Oxygen Blenders - Air & O2 inlets, P regulated, Precision blended for FIO2 & flow, Alarms for O2 delivery outside of set range - Prone to inaccuracy & failure