Abby Erickson, RRT Review of RT 110

 Performed by: Hand Machine  Available for: Short term Long term Acute care Extended home care

 S-shaped curve, relationship of plasma PO 2 and O 2 bound to Hb (SO 2 )  Flat portion: minor changes in PO 2 have little effect on SO 2 Strong Affinity!  Steep portion: small drop in PO 2 causes a large drop in SO 2 Weak Affinity!

 Normal: 4-5L/min  V A = Vt-V D  V A = (Vt-V D )x f  ↑ V A = ↓ PaCO 2, ↑ PaO 2 Hyperventilation  ↓ V A = ↑ PaCO 2, ↓ PaO 2 Hypoventilation  Alveolar air equation  As PaCO 2 ↑ by 1mmHg, PaO 2 ↓ by 1.25mmHg...

 Degree of compensation  Acid-base balance  Cause: respiratory, metabolic, mixed  Oxygenation – degree of hypoxemia  Must interpret in the context of the clinical picture!! Requires ventilation status History, signs, symptoms  Acute changes versus chronic

 P awo : zero*  P bs : zero*  P pl : -5cmH2O - 10cmH2O  P A : +1cmH2O - 1cmH2O *unless pressure applied

 Relative ease with which a structure distends opposite of elastance  Used to describe the elastic forces that oppose lung inflation   V/  P = L/cmH2O  ml/cmH2O normal  35/ ml/cmH2O intubated patient  Static Compliance  Dynamic Compliance

 Frictional forces associated with ventilation Anatomic structures Tissue viscous resistance  Ability of air to flow depends on Gas viscosity Gas density Length and diameter of the tube Flow rate of the gas through the tube  Raw = P TA /flow cmH2O/L/sec P TA ≈ PIP – Pplat Assumes constant flow  Normal cmH2O/L/sec  Intubated patients 5-7cmH2O/L/sec (and higher!)

 Attempts to mimic normal physiology  Types: Iron lung – tank ventilator Chest cuirass  Maintained without the need for ETT, tracheostomy, able to talk and eat  Cardiovascular concerns, access to patient

 Above normal ventilating rates with below normal ventilating volumes  HFPPV  HFJV  HFOV

 Requires airway interface  Applies pressure to create gradient between mouth and lung

ELECTRICALLY POWEREDPNEUMATICALLY POWERED  Relies on electricity  Wall outlet (AC), battery (DC)  Powers internal motors which provide gas flow to the patient  High pressure gas source  Usually 2 -50psi sources, air and oxygen  Built in reducing valves  Pneumatic  Fluidic

 Pneumatically powered – 50 psi gas sources Mixture of air and oxygen allow variable FiO2 Energy to deliver the breath  Electrically powered Controls the internal function May be controlled by a microprocessor (1980’s)

OPEN LOOPCLOSED LOOP  “unintelligent” systems  Does not respond to changes in patient condition  Does not measure variables or change them  “intelligent” systems  Compares the set variable to the measured variable

 Main inspiratory line  Adapter  Expiratory line  Expiratory valve  Adjuncts Device to warm/humidify air Thermometer Nebulizer Bacteria filters

 Muscle Pressure Action of the respiratory muscles  Ventilation Pressure Produced by the ventilator These pressures produce motion (flow) to deliver a volume of gas to the lung; the volume delivered depends on the lung’s characteristics

PRESSURE CONTROLLED BREATHING VOLUME CONTROLLED BREATHING  Maintains the pressure waveform in a specific pattern  Pressure waveform is unaffected by changes in lung characteristics  Volume and flow waveforms vary with changes in lung characteristics  Maintains the volume waveform in a specific pattern  Volume and flow waveforms remain unchanged  Pressure waveform varies with changes in lung characteristics

 Change from exhalation to inspiration  Inspiration  Change from inspiration to exhalation  exhalation

 Signal measured by the ventilator  Begins, sustains and ends each of the four phases of the breath Trigger variable Limit variable Cycle variable

MANDATORYSPONTANEOUS  Ventilator determines start time  Ventilator determines tidal volume  Ventilator determines both  Machine triggers and/or cycles the breath  Patient determines start of breath  Patient determines tidal volume delivery

 Does not require an endotracheal tube  Use of NPPV has the potential: to avoid complications of intubation decrease mortality rates decrease length of stay

 Achieve exhaled tidal volume 5-7ml/kg  Patient ventilator synchrony Rise time Inspiratory sensitivity Expiratory flow cycling EPAP to offset autoPEEP  Oximetry  Alleviating disease/disorder signs and symptoms

 Requires patient cooperation and tolerance  Selection of appropriate interface  Starting with low pressure initially  Allow the patient to hold the mask  Reassurance  Requires secure fit, leaks are acceptable

 Mask discomfort  Air pressures/Gas flows –gastric insufflation  Aspiration pneumonia  Pneumothorax  Hypotension  Hypoxemia, Mucus plugging  Respiratory arrest

 Reversal of the cause of respiratory failure  Stabilization of the patient's condition  Gradually decreasing the level of support (both ventilatory and oxygenation)  Gradually increase the amount of time off NPPV

 The rest of the book!  Stay on top of the reading, this term moves fast  Come and see me for questions, concerns and further review, I am here to help  Class time is limited so plan on additional time for independent study