Test 2 Flashcards
Oxygen Induced Hypo-ventilation
- Decreased PaO2 will stimulate the patient to breathe
- Satisfying oxygen demand may induce hypoventilation and can cause the patient to slow down their breathing.
- COPD patient Do Not need to fully correct hypoxemia
- PO2 60 torr
- SaO2 90%
- Maintain the “hypoxic drive” – attempt to meet most of the body’s requirement at LOW level energy expenditure
- Low flow oxygen (high FiO2) will aggravate the hypoventilation
- USE high flow (LOW FiO2) – ex. Venti Mask is best
Duration of use of Cylinders
Duration of flow (min) = Pressure (PSI) X Cylinder factor / Flow (LPM)
Minute Ventilation
VE= Tidal Volume X Respiratory Rate
Normal Tidal Volume is around 500 mL
Normal RR is around 12-14 breaths
Humidity Deficit
– Inspired air that is not fully saturated at body temperature
– Deficit is corrected by body’s own humidification system
– Humidity deficit = 44 mg/L – absolute humidity
• 44 mg/liter – 16.88 mg/liter = 27.12 mg/liter
Body Deficit
– Relative humidity at body temperature & is expressed as percentage
– Capacity of water at body temperature is 44mg/L
– Body humidity = absolute humidity/ 44mg/L x 100
Relative Humidity
– basically when a gas is not fully saturated, its water vapor content is called RH – Ratio between amount of water in given volume of gas & maximum amount it is capable of holding at that temperature– Expressed as percentage & is obtained with hygrometer
Relative humidity = absolute humidity/capacity x 100
Inspiratory Flow-rate
IF = (I:E) x VE Example: You are breathing I:E of 1:2 Your f = 12 Your Vt = 0.5L (1+2) x (12 x 0.5L) = (3) x (6 L) = 18 L/min
Total Flow
= (Air : O2) x O2 Flow Rate Air:O2 for 40% is 3:1 Recommended flow rate is 8 LPM Total flow = 4 x 8 LPM Total flow = 32 LPM
Oxygen Toxicity
A condition resulting from breathing high partial pressures of oxygen, characterized by visual and hearing abnormalities, unusual fatigue, muscular twitching, anxiety, confusion, incoordination, and convulsions.
Hyperoxemia
Higher than normal levels of oxygen in the blood.
Absorption Atelectasis
If a large volume of nitrogen in the lungs is replaced with oxygen, the oxygen may subsequently be absorbed into the blood, reducing the volume of the alveoli, resulting in a form of alveolar collapse.
Retinopathy
An abnormal ocular condition that occurs in some premature or low-birth- weight infants who receive O2. The risk of ROP in infants can be minimized by keeping the PO2 less than 80 mm HG.
Cor Pulmonale
is defined as an alteration in the structure and function of the right ventricle (RV) of the heart caused by a primary disorder of the respiratory system. Pulmonary hypertension is often the common link between lung dysfunction and the heart in cor pulmonale.
Congestive Heart Failure (CHF)
An abnormal condition that reflects impaired cardiac pumping; caused by myocardial infarction, ischemic heart disease, or cardiomyopathy that results in either pulmonary or systemic edema. (Left side and left ventricle is affected)
Co-oximetry
most current CO-oximeters will detect the relative levels of each hemoglobin fraction (oxyhemoglobin and dyshemoglobins) and likely the oxyhemoglobin saturation. For any system making these measurements it is critical that the device clearly distinguish between Oxygen Saturation’ and Fractional Oxyhemoglobin” .
Hypoxic Drive
A form of respiratory drive in which the body uses oxygen chemoreceptors instead of carbon dioxide receptors to regulate the respiratory cycle.
Venturi Mask: fixed FiO2 pulse oximetry 88-92%
Heliox
80:20 = 1.8
70:30 = 1.6
Multiply the factor by flow given.
PISS
Pin-indexed safety system. E cylinder
TISS
Thread index safety system
DISS
Diameter-Index Safety System
ASSS
American Standard Safety System. H or G Cylinders
National Fire Protection Agency (NFPA)
The NFPA sets the standards for storing medical gases- including liquid oxygen systems.
Food and Drug Administration (FDA)
The FDA determines purity standards & labeling for all medical gases
Compressed Gas Association (CGA)
Sets the safety standards by making recommendations to manufacturers & municipal authorities
Department of Transportation (DOT)
DOT is responsible for construction standards, transport standards, and testing standards of cylinders.
Hyperbaric Oxygen (HBO)
Oxygen utilized at higher than atmospheric pressures. Boyle’s law dictates that high pressure exerts a physical effect on air or nitrogen bubbles trapped in the blood or tissues, reducing their size, and minimizing potential harm.
Indications for Oxygen
Hypoxemia Increased WOB Excessive myocardial work Trauma Acute MI Short term therapy Surgical Intervention
Henry’s Law
GAS CAN DISSOLVE IN LIQUID•EXAMPLE: CARBONATED WATER & SODA (CO2) DISSOLVED IN (WATER) LIQUID
Gram’s Law
RATE OF DIFFUSION INVERSELY RELATED TO MOLECULAR WEIGHT
Fick’s Law
- BASICALLY GAS MOVES FROM A HIGHER PRESSURE TO A LOWER PRESSURE
- RATE OF DIFFUSION ACROSS A MEMBRANE IS DIRECTLY PROPORTIONAL TO THE SURFACE AREA OF THE MEMBRANE, DIRECTLY PROPORTIONAL TO THE PRESSURE GRADIENT, AND INVERSELY PROPORTIONAL TO THE MEMBRANE THICKNESS
Dalton’s Law
SUM OF THE INDIVIDUAL PARTIAL PRESSURES OF A GAS = TO PARTIAL PRESSURE OF THE GAS
Absolute Humidity
– Amount of water in given volume of gas
– common unit of measure is mg/L
AH = 33.76 mg/liter x 0.50 (the RH) = 16.88 mg/liter
Hypoxia
Reduced level of tissue oxygenation
Hypoxemia
Decrease in the partial pressure of oxygen in the blood
Hazard for aerosol therapy
Swelling of secretions
Increased airway resistance
Fluid overload
Cross contamination
Indications for humidity
The main indication for humidity is to Prevent a humidity deficit
Correct humidity deficit
Bland Aerosol
-Mist
Prevent humidity deficit
Humidifiers
- Water Vapor
- Heated
