Difference between reducing valve and regulator, operation of flow restrictors, Bourdon gauges, and Thorpe tubes, effects of downstream pressure on meters, laboratory value that increases during hypoxia, clinical signs of mild/moderate and severe hypoxia,
Minimum criterion for checking O2 delivery system
Once per day, more frequent checks for susceptible systems
Precautions of oxygen therapy
Oxygen toxicity, Depression of ventilation, Retinopathy of prematurity, Absorption atelectasis
Downstream pressure effects on compensated Thorpe tubes
Prevents changes in downstream resistance from affecting meter accuracy
Flow resistance
Principle on which flow restrictor operates
Pressure compensated Thorpe tube
Thorpe tube calibrated at 50-psig to prevent downstream resistance affecting accuracy
Pressure uncompensated Thorpe tube
Thorpe tube calibrated in liters per minute at atmospheric pressure
Nasal cannula oxygen percentages
1L = 24%, 2L = 28%, 3L = 32%, 5L = 40%, 6L = 44%
Minimum flow to flush CO2 from a Hood
8 L/min
Measured laboratory value that increases during hypoxia
Carbon Dioxide (PaCO2)
Regulator
Combination of flow meter and reducing valve to control pressure and flow
Bourdon gauge
Fixed-orifice, variable-pressure flow meter used with adjustable pressure-reducing valve
Best method of providing controlled oxygen therapy to an infant
Hoods and Blender
Administering oxygen to adults, children, and infants
Hoods, Worm, NC, Incubator
Downstream pressure effects on uncompensated Thorpe tubes
Increase in downstream pressure causes tube to show lower flow than actually delivered
Downstream pressure effects on Bourdon gauge
Increase in downstream pressure decreases pressure difference across orifice and actual output flow
Complications of oxygen therapy
Infiltrates in lung parenchyma, Oxygen-induced hypercapnia, Retinal vasoconstriction and necrosis, Absorption atelectasis
AAP recommendation for minimizing risk of ROP
Maintain arterial PO2 less than 80 mmHg
Quantify gas flow
Measure gas flow through a tube
Partial mask oxygen therapy
Minimum flow is 10 L/min, keep at least 2/3 full
Administering heliox therapy
Non-rebreathing mask attached to heliox cylinder for upper airway obstruction, croup, laryngeal edema, severe asthma
Reducing valve
Reduces gas pressure in a system
Flow restrictor
Simplest and least expensive flow meter device with fixed orifice
COPD oxygen therapy
Start with 2L, increase later
Clinical signs of severe hypoxia
Tachypnea, Dyspnea, Cyanosis, Tachycardia, Eventual bradycardia, Arrhythmia, Hypertension, Eventual hypotension, Somnolence, Confusion, Distressed appearance, Blurred Vision, Tunnel Vision, Loss of Coordination, Impaired Judgement, Slow Reaction Time, Manic-depressive activity, Coma
Clinical signs of mild/moderate hypoxia
Tachypnea, Dyspnea, Paleness, Tachycardia, Mild hypertension, Peripheral vasoconstriction, Restlessness, Disorientation, Headaches, Lassitude
Thorpe tube
Variable-orifice, constant-pressure flow meter used to measure true flow