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Pandemic [H1N1] 2009 RT Education Module 1. Ventilation. Outline. Indications for Ventilation Standard Modes of Ventilation Weaning Controlled modes to support modes Weaning protocol (RAH) Factors Associated with Difficulty Weaning Plugging (to be added) Speaking valves (to be added)
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Pandemic [H1N1] 2009RT EducationModule 1 Ventilation
Outline • Indications for Ventilation • Standard Modes of Ventilation • Weaning • Controlled modes to support modes • Weaning protocol (RAH) • Factors Associated with Difficulty Weaning • Plugging (to be added) • Speaking valves (to be added) • Non-Invasive Ventilation: An overview • The VISIONS Ventilator (to be added) • Ventilators and their Modes
To Ventilate or not to Ventilate • There are no rules, just guidelines: • Acute Respiratory Failure • Impending Respiratory Failure • Apnea • Hypoxic Respiratory Failure • [post-op care]
Standard Modes of Ventilation Full Support Partial Support Spontaneous Breathing
Which Mode to Choose? • What is the indication? • Does the patient have lung disease? • Is the respiratory centre functioning? • Lung Mechanics? • Compliance vs. Resistance • How much support does the patient need? • Is the patient making spontaneous efforts? • How hard is my patient working to maintain ventilation?
Full Support Volume Cycled Breaths versus Pressure Limited Breaths OR A little of BOTH
Set Parameters: Tidal volume (Vt) Respiratory Rate (RR) Inspiratory time (Ti) PEEP FiO2 If the patient wants additional breaths, they are delivered according to set parameters. Variable Parameters: Peak inspiratory pressure (PIP) will vary with changes in resistance and/or compliance (Cp). Resistance = PIP Cp = PIP Volume Ventilation: VC – CMV - A/C
Set Parameters: Pressure (PC) RR Ti PEEP FiO2 Patient is able to trigger additional breaths that will be delivered with the set parameters. Variable Parameters: Vt will vary with changes in lung mechanics. Resistance = Vt Cp = Vt Pressure Ventilation: PCV - PCV+Assist
Set Parameters: Vt RR Ti PEEP FiO2 If the patient wants additional breaths, they are delivered according to set parameters. Variable Parameters: PIP will vary with changes in resistance and/or compliance. Ventilator automatically adjust pressure needed to ensure tidal volume is delivered. Resistance/Cp = PIP Resistance/Cp = PIP Pressure Control with Volume Guarantee: PRVC – CMV (autoflow) – VC+
Partial Support Volume Cycled Breaths Pressure Limited Breaths
Set Parameters: RR Vt or PC for mandatory breaths Ti PEEP FiO2 PSV for any spontaneous breaths taken by the patient. Trigger window is established allowing patient to spontaneously breath on PSV, if no effort is made then a mandatory breath is delivered. Synchronized Intermittent Mandatory Ventilation (SIMV): SIMV (VC) + PSV - SIMV (PC) + PSV - SIMV (PRVC) + PSV
Set Parameters: PS level which provides an inspiratory ‘boost’ to augment the spontaneous tidal volume. PEEP FiO2 Variable Parameters: RR Vt will vary Changes in lung mechanics Patient effort Pressure Support: PSV
Proportional Assist Ventilation: PAV • Currently only available on the PB 840. • Patients must have an intact respiratory drive. • Support from the ventilator is proportional to the patients effort. • Patient effort is amplified by % support (set by operator). • Synchrony is assured since machine assistance is applied only when there is an effort from the patient.
Set Parameters: % support Amount of pressure that is used to augmentation to a patient effort. NO EFFORT = NO BREATH DELIVERY FiO2 Variable Parameters: RR Vt PIP Proportional Assist Ventilation: PAV
SPONTANEOUS BREATHING CPAP Weaning
Set Parameters: Pressure Variable Parameters: Everything else! Continuous Positive Airway Pressure: CPAP
Weaning • Weaning must be tailored to fit the needs of each individual patient. • Contributing Factors: • Surgeries • Complications • Length of time on the ventilator • Patient condition prior to intubation • Age • LOC [level of consciousness] • Co-morbities • Type of airway
Weaning • RAH Weaning Protocol: • Purpose: • To facilitate timely and eventual removal of ventilatory support as part of patient discharge from the ICU. • Special Considerations: • The weaning protocol will be initiated on patients who have been in AICU for at least 24 hours and/or have been assessed by the attending physician/chief resident with the appropriate order written. • Assessment for weaning will be based on the defined criteria. • Assessment during weaning will be based on the defined criteria. • Extubation will occur promptly following assessment of CXR.
Assessment for Weaning ASSESSMENT FOR WEANING TRIAL • Hemoglobin > 70 mg/dl • PaO2 ≥ 60 • FiO2 ≤ 45 • PEEP at : • Measured autoPEEP OR • PEEP of 5 cmH2O • RSBI ≤ 140 • Adequate cough • GCS ≥ 11 • No infusions of vasopressors or sedatives • Endotracheal tube cuff leak present [Evaluate in A/C and assess if there is a Ventilation Volume loss of 105 ml, with tidal volume being no less than 400ml NIF ≥ 20 cmH2O ( for patients ventilated greater than 48 hrs)]
Failure to Wean ASSESSMENT DURING WEANING TRIAL – FAILURE TO WEAN IS DEFINED BY: • SpO2 < 90% for 5 minutes • RR > 35 • HR 25% change from baseline for 10 min • BP < 90 mmHg or >200 mmHg • Abnormal paradox • Diaphoresis • Anxiety unresponsive to anti-anxiety measures • ↓ LOC • Deterioration of Chest X-Ray
Weaning • CPAP Trials: • Patient Population: Chrionic ventialted patients, difficult to wean or those with poor respiratory muscle strength. • Patient breathes on CPAP for short periods of time, progressively getting longer. • Patient rested on full ventilatory support mode.
Factors Associated with Difficulty Weaning • Cardiovascular collapse. • Poor muscle strength or atrophy. • Increased work of breathing. • Excessive secretions. • Patient not psychologically or physiologically ready. • Primary illness not resolved. • Improper weaning procedure or patient cannot be weaned (terminal illness). • Pulmonary complications (e.g. atelectasis, pulmonary infection, bronchospasm). • Poor nutrition. • Continued use of sedatives or analgesics. • Acid-base imbalance. • Electrolyte imbalance. • Abdominal distension. • Anemia. • Fluid overload. • Renal failure. • Malfunction of equipment.
VC PCV PRVC SIMV(VC) + PSV SIMV(PC) + PSV VS PS CPAP SERVO 300
VC PC PRVC SIMV(VC) + PSV SIMV(PC) + PSV SIMV(PRVC) + PSV VS PS CPAP Bi-Vent NIV SERVO-i
AC VC+ PCV SIMV PSV PAV CPAP Bi-Level NIV PB 840
CMV CMV (autoflow) PCV PCV +Assist APRV PSV CPAP NIV EVITA
CPAP S/T (BiPAP) PAV BiPAP Visions
Non-Invasive Ventilation • The application of positive pressure through a mask to the upper airway and lung fields. • The pressure applied aids in stabilization of the upper airway to allow for adequate movement of air into the lungs. • The mask can be applied to just the nose [nasal] or to both the nose and mouth [full face]. • Mask used will depend on amount of assistance required. • Pressure applied can be on a constant basis [CPAP)] or in two phases [BiPAP] that mimics inspiration and expiration. • Method of pressure delivery will be determined by the type of assistance required.
CPAP Continuous Positive Airway Pressure Splints airway open to allow for movement of air into the lungs. BiPAP Bi-level Positive Airway Pressure The inspiratory pressure provides a boost to inspiration which means a bigger breath with less effort by the individual. The expiratory pressure is to keep the airway open while exhaling. Modes of Non-invasive Ventilation
What is this ‘VISION’ you speak of? • What the manual says: “The VISION ventilator is a microprocessor-controlled positive pressure ventilatory assist system.”
What does that mean? • The VISION ventilator provides positive airway pressure and positive pressure ventilation in non-invasive situations. • It is indicated for assisted ventilation and is intended to augment a spontaneously breathing patient. • The VISION ventilator has the ability to provide total ventilatory support. • NOTE! At the RAH we will not be providing total ventilatory support with this machine!
How does it work? • Pressure regulation is achieved on the VISION ventilator through a series of algorithms. • By monitoring proximal airway pressure and adjusting flows generated by the machine, the ventilator is able to ensure that the proximal pressure is equal to the set pressure.
What can the VISION ventilator do for my patients? • Provides % oxygen-this is key! • Provides 3 modes of NIMV: • CPAP • BIPAP (S/T) • PAV/T (Proportional Assist Ventilation) • Leak compensated • Alarms for patient safety • Set up for adequate humidification • Circuit has a built in leak valve=CASTLE VALVE
Initializing • Designated VISION’s circuit • Pressure line adaptor • Heated Wide bore hose • Castle Valve • Square Green Filter • Humidifier and sterile water bag • Calibrated O2 Analyzer and analyzer t-in • Rubber adaptor • Temperature probe • Mask
Initializing Specialty Bits and Pieces • O2 module versus O2 t-in: • Bayonet style • RAH will be using the O2 module only • Controls the concentration from 21%-100% • A more stable and reliable method of oxygen delivery • Displays a % of O2. • Must use with an O2 analyzer. • Accurate within +3% FiO2 or • Accurate within +10% set FiO2
Initializing Specialty Bits and Pieces • Castle Valve • Clear plastic adjunct to the circuit • Should never be removed from the circuit • Continuous flow from the valve flushes exhaled gases from the circuit. • Occlusion of this port is potentially dangerous. • Necessary for the Exhalation Port test • Included in the disposable circuit package
Initializing • Performance Verification • CLEAN IT! • CIRCUIT IT! • CHECK IT!
Initializing • Exhalation Port Test • This must be done!! • During the test the system learns the intentional leak, stores it in its memory and uses it to perform leak calculations and provide an accurate display of patient leak, Vt and MV. • In turn, accurate Vt and MV will ensure the alarms are able to activate appropriately.
The Meat and Potatoes • Modes of Ventilation • CPAP • S/T (BIPAP) • Proportional Assist Ventilation (PAV/T)
CPAP • Same old, same old
ACTIVE EPAP (set) %O2 ACTIVELY INACTIVE Learn Base Flow Back up rate MEASURED EPAP Rate Vtexh MV PIP Leak Ti/Ttot INACTIVE IPAP Rise Time CPAP
APNEA Interval ALARMS Hi Pressure Limit (Hi P) Low Pressure Limit (Lo P) Low Pressure Alarm Delay (Lo P Delay) Low Minute Ventilation (Lo MinVent) High Rate (Hi Rate) Low Rate (Lo Rate) Those Crazy Alarms
S/T • “…the S/T mode of the VISION ventilator delivers pressure support with PEEP” • Fancy way of saying it provides IPAP and EPAP but displays the difference in pressure as “PS”. • Referenced as S/T=Spontaneously Timed • This means that the machine is capable of delivering timed breaths if the patient’s RR decreases to or below a set limit.
S/T • This mode is set up exactly like the BIPAP we know and love!
What is a Timed Breath? • A timed breath is a machine triggered, pressure-limited, time-cycled, pressure controlled breath at the set IPAP level. The Inspiratory Time control controls the length of the breath. • A machine controlled breath will be indicated on the volume waveform by a tiny little ‘V’ right on the wave form.
ACTIVE IPAP (set) EPAP (set) %O2 (set) Rise Time (IPAP) ACTIVELY INACTIVE Learn Base Flow MEASURED IPAP EPAP Rate Vtexh MV PIP Leak Ti/Ttot %Patient-Triggered breaths S/T
APNEA Interval (set) Rate (set) ALARMS Hi P Lo P Lo P Delay Lo Rate Lo MinVent Those Crazy Alarms
Say What? • PAV/T= Proportional Assist Ventilation/Timed • “…combines patient triggered breaths that can deliver pressure in proportion to effort (PAV) and a preset backup rate that activates machine-triggered, pressure limited, time-cycled breaths (Timed).”