SLE 5000 NEONATAL VENTILATOR, Dr Abid ali Rizvi, NICU Maternity Hospital kUWAIT
ARE YOU MAKING THE BESTUSE OF SLE 5000VENTILATOR
AIM•This presentation is nota substitute for readingthe user manualindividually, anddiscussing at bedsidewhat is not clear.•A human life is hangingat the other end of ourcompetence.•Work-up your ownopinion, but follow theconsultants preferencestrictly in setting up the WILL YOU BUY Aventilation of the baby. TICKET ON THIS AIRLINE’S FLIGHT?
CMV OR PTV CMV = IMV = [SIMV or PTV with trigger disabled] PTV = A/C (baby controls the ventilator rate). PSV = A/C but with Flow cycling (Baby controls the Ti also). SIMV + PSV = detailed in separate slide. HFO and HFO+CMV = presentation will become too lengthy.
CMV & IMV: by definition… Continuous Mandatory Ventilation: Used most often in the paralyzed or apneic patients. The ventilator rate is set faster than the patients own breathing rate. Intermittent Mandatory Ventilation: The ventilator rate is lower (less than 30 bpm), therefore the patient gets chance to breathe spontaneously between two controlled breaths. In both CMV and IMV, breaths are delivered regardless of the patients effort. Synchronization is not intended in either of these.
IMV-CMV FAN CLUBComplications due to lack of synchronized ventilation are well known.
Adjusting Trigger Sensitivity Default trigger sensitivity to detect the patients breath effort is 2L/min, which will not detect the breathing in any premature baby, and then PTV, SIMV or PSV- all will work as CMV. Make the trigger (flow sensor) work by decreasing the threshold to 0.4-0.6 in most cases. Orange lines should be visible in the real time graphs.
PTV becomes CMV when trigger is not adjustedbelow the peak inspiratory flow
Orange lines: depict the neonate’s breathing efforts in the first 0.2 seconds of the TiThis dipbeforeinspirationassurestruetriggering Ti
Using SIMV with PS Once again the heart of PS is the flow cycling of inspiration. Keep inspiration termination criteria at 5% of the peak insp. flow for neonates. Pressure support for the non-SIMV breaths should be set initially liberally (start with ~80% of PIP values), and then bring it down to 4-5 mbars above PEEP in 1-2 days if possible.
On selecting SIMV, PS setup is offered in the same window.
On selecting PS withSIMV, these 2parameter have to beadjusted. Only for the non-SIMV breaths (free ones, over the set rate), to counter the imposed work of breathing, reducing exhaustion, and the energy expenditure. 0 – 100% The mandatory cycles will follow the set PIP. Flow cycling applies only to the non-SIMV breaths that are now getting some extra help during inspiration. The mandatory cycles will follow the set Ti (time cycled).
I KNOW EVERY THING.YOUR GIMMICKS DON’T IMPRESS ME.
PSV with Volume Targeted Ventilation Its user friendly in SLEThis is theonly extradial onscreen.
Using TTV (Targeted Tidal Volume)• This option is available in all modes, best used with PTV for uniformity of delivered tidal volumes (c.f. with SIMV).• Press it ON,• Set the desired tidal volume in ml.• Set the automatic ET leak compensation to 20%• Let the baby get benefit of auto-weaning of PIP especially after Survanta administration, when compliance increases.• Contra-indication for TTV: ETT leaks > 20%.
Yourpneumothoraxprevention buttonForget me if youdon’t likesynchronization.ET leakcompensation,Pressurewave formsettings here. Flow cycling of inspiration in PSV mode
It’s the tidal volume that causes Pneumothorax not the pressure Set the desired tidal volume at 6 ml/kg, to get best results. Range is 4-6 ml/kg. When choosing in this range, consider: Work of breathing, pCO2, Hyperinflation, BPD, MAS. Pre-existing barotrauma, Dead space compartment due to prematurity, flow sensor (1 ml).
ET Leak Measured inspired vol minus measured expired vol. Automatic leak compensation means that ventilator software will display the expiratory tidal volume (Vte) inclusive of the amount that leaked out from the sides of trachea during expiration. In SLE 5000, there is Automatic Leak Compensation up to 20% if on TTV mode, and 50% in PTV, SIMV and PSV mode. We have to enable it from the “options” box after selecting the mode of ventilation. If ET leak is > 50% all the time, most authorities recommend to change ET to a bigger size.
Selecting pressure wave form:“RISE TIME”In brief:• Square wave: for stiff lungs.• Sinus wave: for healthier lungs.• We have to select the pressure wave pattern from “options” menu.• Default setting is towards the square wave in SLE 5000.
Shifting fromHFO toConventional.Do not press theconfirm buttonwithout correctingthe PEEP to 4 or 5cmH2O, otherwisethe PaW of HFO willbe delivered asPEEP in conventionventilation.Consequences maynot be pleasant.
Measured values on righthand column.TiBPM tot:TriggerVte (ml)Vmin (Liters)Leak%Resistance (cmH2O/l/sec)Compliance (ml/cmH2O)C20/C ratio (ratio)Mean (Airway) Pressure (mbar)HFO VTe (Vol. of Oscillation in ml)DCO2: Gas Transport Coefficient
MY LEARNINGCURVES OF OURVENTILATORMACHINES bear cub 750
Measured values: Tidal Volume Vte (ml)• Acceptable values: • FT neonate is 4-8 ml/kg • Preterm infant: 4 –6ml/kg.
Measured values: Minute volume Vmin (L)• Acceptable Minute Volume: • FT newborn is 200 - 400 ml/kg. • Preterm: 200- 300 ml/kg• Useful for guessing over or under ventilation before BGA is done.
BPM tot: (tot = total), in 1 minute.Trigger: No. of synchronized breaths in last 1 min. • These values, may not be same as the (back-up) rate you have set in PTV or SIMV. • In PTV mode, for pCO2 manipulation, look at the number of triggered breaths delivered before changing the ventilator rate. • If it is significantly less than the BPM tot, then increasing the trigger sensitivity will increase the no. of assisted breaths.
Using Standby mode or CPAP mode to evaluatepatients actual breathing effort without ET disconnectionwhen flow sensor is not used. • Pressing Standby button for 3 second will suspend ventilation for maximum of 90 sec, although it can restarted any time before 90 sec, by repressing it. • Ventilator maintains MAP during this period to avoid derecruitment. • Those on low settings, CPAP mode will be safer to manually assess the spontaneous breathing.
BPM measurement• The ventilator measures BPM in 2 different ways, with or without a flow sensor. • With flow sensor: All breaths are counted: Triggered, Spontaneous, and Mandatory. • Without flow sensor: Only triggered and mandatory breaths are counted by the pressure sensor located inside the machine.
Measured values: Resistance (cmH2O/L/sec)• Acceptable: • ET 2.5: 130 to150. • ET 3 - 3.5: 50-80.• Very high values (eg 300 or more) should never be neglected.• Common reasons: • Kinked or partially blocked ET, • ET impinging on carina, • Recent suvanta administration, • Thick secretions in the airway, • Severe BPD or MAS • Very high PIP & rate together, in 2.5 size ET (high turbulence).
Changing the neck position will solve the problem
Compliance (ml/cmH2O)Acceptable values:Normal FT, not on ventilator: 2-2.5Good for extubation: > 1
C20/C ratio for over-distension Beaking also denotes over- distensionRatio of compliance Total lung complianceduring the last 20% ofbreath cycle to thetotal compliance.If this calculated Compliancevalue is less than of the last 20% of breath0.8 (<1 accordingto some experts),the lungs areoverinflated,therefore PIPshould be reduced.
Mean (Airway) Pressure (mbar)• This parameter (along with the FiO2) is the summary of what you are doing to the baby.• Suggestion: MAP should be recorded in the BGA chart. Currently its not.
HFO VTe (Vol. of Oscillation) in ml• Volume of air moved in (and out) with each oscillator piston movement.• Delta P is an indirect representation of this volume.• Values of 2-2.5 ml/kg will give you normal pCO2. (This is the anatomical dead space volume in neonates).• Useful as an adjuvant to chest vibration.
DCO2: Gas Transport Coefficient• DCO2 = VT2 X F• Values around 80 per kg will result in normocarbia.• Useful when chest is not visible due to bandage; or when gross edema with tense ascites causes poor vibrations.