270 likes | 291 Views
NON INVASIVE MONITORS. Pulse oximetry. An inexpensive and noninvasive method to measure arterial blood hemoglobin saturations Measures SpO2 Oxygenation in capillary blood. Pulse oximetry. Indications Monitor adequacy of arterial Oxyhemoglobin Quantify response to therapeutic procedures
E N D
Pulse oximetry • An inexpensive and noninvasive method to measure arterial blood hemoglobin saturations • Measures SpO2 • Oxygenation in capillary blood
Pulse oximetry • Indications • Monitor adequacy of arterial Oxyhemoglobin • Quantify response to therapeutic procedures • Comply with mandated regulations • Contraindications • The need for ongoing actual measurement of Ph, PCO2, PaO2 • Abnormal hemoglobin
Pulse oximetry • Precautions/complications • False readings • Tissue injury • Assessment of need • Direct measurement not readily available • Continuous and prolonged measurements • When acid-base status not needed • Assessment of outcome • SpO2 should reflect condition • Documentation of results and intervention
Pulse oximetry • Frequency • Determined by clinical status of patient
Pulse oximetry • Instrumentation • Uses photoplesmography • Light detects volume changes in pulsatile blood flow • Uses red and infrared light • Transmitter – two sided • LED’s transmit light through tissue • Intensity of light measured through photodetector on other side
Pulse oximetry • Output signal is filtered and amplified • Processed and displayed
Pulse ox • Components of absorption • Baseline • Pulsatile
Pulse ox • Accuracy • Falls within ± 3-5% of ABG’s • As SpO2 falls, the accuracy will also fall • Not accurate with saturations below 70%
Pulse ox • Procedure • Follow manufactures protocol • Never mix components • Sensor must be right size, fit • Confirm good signal, allow time • Set low SpO2 88-92% • Validate baseline with ABG • Clean and disinfect between patients • Inspect probe site frequently • Never act on SpO2 readings alone • Careful with readings
Pulse ox • Documentation • Date and time • Patients position, location of probe, activity • FiO2 or O2 flow at time of reading • Model of pulse ox • Comparison of SpO2 to ABG • Stability of readings • Patients clinical appearance • Document HR on pulse ox to manual palpitation of HR
Pulse ox • Factors effecting efficiency • COHb • MetHb • Fetal Hb • Anemia • Vascular dyes • Billirubin • Dark skin pigmentation • Poor perfusion • Motion artifact • Nail polish • Ambient light
Pulse ox • ALWAYS TREAT THE PATIENT. NOT THE NUMBER
End Tidal CO2 • Capnometry • The measurement of CO2 in respiratory gases • Capnometer • Instrument that measures end tidal CO2 • Capnography • The graphic display of CO2 concentrations versus time • Shows changes with every breath
ETCO2 • Indications • Evaluate CO2 in mechanically ventilated patients • Monitoring severity of pulmonary disease and response to treatment • Determine tracheal vs. esophageal intubation • Monitor integrity of vent circuit, artificial airway, and ventilator • Reflect CO2 elimination • Monitor inhaled CO2 during therapeutic CO2 administration
ETCO2 • Contraindications • None, remember that your treating the patient, not the number • Precautions • Misunderstanding the numbers • Weighing down the vent circuit • Assessment of need • Standard of care in OR • Assessment of outcome • Results should reflect patients appearance • Monitoring • Vent params • Hemodynamics
ETCO2 • Instrumentation • Infrared absorption • Most common • Raman scattering • Mass spectroscopy • Photoacustic technology
ETCO2 • Sampling ports are either sidestream or mainstream
ETCO2 • Mainstream • In line analyzer chamber placed between the patients airway and the vent circuit • Advantages • Sensor at airway • Fast response • No sample flow • Disadvantages • Secretions and humidity block sensor window • Frequent calibration • Bulky and heavy • Non disposable • Intubated patients only
ETCO2 • Sidestream • Sampling tube placed between patient and circuit, air pumped into measuring chamber
ETCO2 • Advantages • No bulky sensor • Measures N2O • Disposable sample line • Use with non intubated patients • Disadvantages • Secretions block sample tube • Trap needed to remove excess water • Frequent calibration • Slow response • Sample flow may decrease tidal volume
ETCO2 • Waveform interpretation • I • CO2 zero. Origination of exhalation, deadspace • II • Steep upward slope, mixed deadspace gas and alveolar gas • III • Plateau, alveoli empty, end of plateau is PetCO2 • IV • Rapid decrease in CO2, patient inhalation
ETCO2 • In healthy individuals, the PetCO2 averages 1-5mmHg lower than ABG’s (5-6%)
ETCO2 abnormal waveforms • Hypoventilation • Hyperventilation • Leak
ETCO2 abnormal waveforms • Disconnect
Transcutaneous monitors • Provides continuous noninvasive estimated PO2 and PCO2 • Heats blood to arterialize it • Dependant on age and perfusion status • CO2 more reliable • Used mostly in the NICU