3 CentriMag System Components The CentriMag is the first disposable, extracorporeal short-term magnetically levitated blood pump. The components are a polycarbonate pump which sits in the motor and is driven by a console.Each of these components will be further described on following slides.Pump Motor Console
4 CentriMag Pump Disposable pump head Medical grade polycarbonate 31cc priming volume3/8” barbed inlet and outletNo bearing or sealsMax. pump speed rpmMax. flow lpmMax pressure mmHgThe CentriMag is a centrifugal pump with a magnetically levitated and driven impeller. There are two magnetic forces in play – a passive magnetic force raises the impeller and an active magnetic force which is created by electrical current in the motor centers and spins the impeller causing forward flow.Elimination of seals and bearings – elimination of friction and heat generation in the blood path reducing the risk for thrombus formation and hemolysis. Additionally, seals and bearings are the failure mode on other centrifugal pumps.The blood enters the pump from the 3/8 inch barbed inlet on the top of the pump, is propelled by the impeller in a circular motion and exits the pump on the side.The pump is single use and disposable. The motor is reusable.The priming volume is 31 cc.Maximum operating pressure is 600 mmHg which allows for the possibility of splicing an oxygenator into the circuit.Maximum speed is 5500 RPM and maximum flow is 9.9 LPM.
5 CentriMag Pump & MotorThe CentriMag pump sits in a reusable motor which applies both levitational and rotational magnetic force.The CentriMag motor employs a unique Bearingless magnetically levitated design
6 Magnetically Levitated CentriMag vs. Magnetically Driven Pump ImpellerPump HousingMagnetic couplingMagn. CouplingStatorSealStatorBearingRotorThe pump on the right is a typical magnetically driven short term pump which is different from a magnetically levitated pump like the CentriMag on the left. This dark line is the disposable portion of the pump. Magnetically driven pumps require a shaft and a bearing to keep the impeller from wobbling. Blood must be kept out of the bearing so there is a seal here. Seals and bearings are the Achilles heel of this type pump because eventually they will fail. But worse than that is probably the fact they have small grinding areas that cause haemolysis and thrombus.The CentriMag magnetically levitated pump eliminates the bearings and seals thus the small gaps and failure modes.Magnetically Levitated CentriMag-Contact-free chamber-No seals-No bearings-Wide blood pathMagnetically Driven Pump
7 The relationship between pressure and flow rate as a function of RPM The relationship between pressure and flow rate as a function of RPM. Graph from Primary Console IFU
8 CentriMag Flow Dynamics This video depicts flow through a magnetically levitated pump. The pump in the video is from Levitronix semiconductor business and is slightly different than the CentriMag design. The hole in the center and the washing effect are the same.Note the complete washing around all aspects of the impeller. The absence of a bearing or spindle allows for a hole in the middle of the impeller which further improves washing.
9 CentriMag SupportThis slide shows the system being used on a patient with a second console in close proximity as a back up. The blood pump is seated in the motor with the back up motor quite close. This particular patient has a HeartMate XVE on the left and a CentriMag to support the right side.(The white covering on the motor is an older heat shield which has since been determined to be unnecessary)Care is taken to insure that lines are not kinkedPrimary Console in use and second Console as back up system
10 CentriMag SupportThis slide shows the system being used on a patient with a second console in close proximity as a back up. The blood pump is seated in the motor with the back up motor quite close. This particular patient has a HeartMate XVE on the left and a CentriMag to support the right side.(The white covering on the motor is an older heat shield which has since been determined to be unnecessary)Care is taken to insure that lines are not kinkedPrimary Console in use and second Console as back up system
11 CentriMag Extracorporeal Blood Pump INDICATIONS FOR USEIndicated to pump blood through the extracorporeal bypass circuit for extracorporeal circulatory support for periods appropriate to cardiopulmonary bypass (up to 6 hours).The CentriMag RVAS is indicated to provide temporary circulatory support for up to 30 days for patients in cardiogenic shock due to acute right ventricular failure.*Read SlideCentriMag has the same FDA clearance as Biopump.*HDE approval
12 Worldwide Regulatory Approvals March k cleared for extracorporeal support up to 6 hoursOctober HDE approval for RVAD use up to 30 daysOctober Pivotal Trial underway to validate use of CentriMag for up to 30 daysApproved for 30 days in EuropeCleared for 6 hours in US, but clinical trials are ongoing to validate the device for longer duration of supportThe CentriMag received aCE certificate in 2002 and isApproved for use in EuropeFor 30 days of support
13 Thoratec CentriMag® Blood Pumping System INDICATIONS FOR USEIndicated to pump blood through the extracorporeal bypass circuit for extracorporeal circulatory support for periods appropriate to cardiopulmonary bypass (up to 6 hours).The CentriMag RVAS is indicated to provide temporary circulatory support for up to 30 days for patients in cardiogenic shock due to acute right ventricular failure.**HDE Approval* HDE approvalRead SlideCentriMag has the same FDA clearance as Biopump.
16 Primary Console Front Panel ROW 1ROW 2Row one has a digital read out of the revolutions per minute, the pump flow in liters per minute, a “fuel gauge” for the battery, and icons which are illuminated depending which power source is used. The Primary Console must be plugged into mains power, but does not need to be turned on when in storage.Row two has lines of text. The top line is your low flow and high flow alarm settings. In the middle would be any alarms or alerts if present. We will discuss alarms and alerts later.The third line describes each of the soft keys on Row three. These are described on the next slide.ROW 3
18 Primary Console Control Panel Alarm Acknowledge - Depressing will silence audio alarm. Message remains displayed. Alarm messages will be displayed in order of priority.Menu – Allows user to select system settings to view or modify – MINIMUM FLOW ALERT, MAXIMUM FLOW ALERT, FLOW LIMIT SENSITIVITY, PRESSURE DISPLAY, SELECT PRESSURE CALIBRATION, SPEED STEP RESOLUTION, LANGUAGE.Set Pump RPM – When ‘SET RPM’ is displayed depress for speed adjustment. If ‘EXIT’ is displayed depress to store value. RPM will remain at set rate.Decrease - Allows user to decrease selected parameter.Increase - Allows user to increase selected parameter.Emergency Stop – Depressing for 2 seconds will cause the pump to STOP.Read slide. Go back to Menu key and use the explanation below:Menu explained on page 21 of Operator’s Manual.MINIMUM FLOW ALERT – default is 0. Use DECREASE and INCREASE arrow keys.Probe can detect retrograde flow of ≥ 40 cc/min and displays retrograde flow as a series of dashes. A disconnected or malfunctioning probe will display blank spaces.MAXIMUM FLOW ALERT - use DECREASE and INCREASE keysFLOW LIMIT SENSITIVITY – Normal is factory default and Sensitive is other choice. Normal = average of last 10 flow data points taken over the last 0.4 seconds. Sensitive = no averaging. Every data flow point is compared to flow limit set by user.PRESSURE DISPLAY – The default setting is INACTIVE. If using console for ECMO, two pressure displays are available – P1 and P2. The range for P1 and P2 is -50 to +900 mmHg. If activated another menu is available (PRESSURE CAL), and the transducers are opened to atmosphere to calibrate then closed.SPEED STEP RESOLUTION – increases the RPMs in steps of 50 or 100.LANGUAGE – English, French, German, Spanish, Dutch and Italian. The language is stored in memory and recalled each time the console is powered up. (Pressing and holding Up Arrow key for 10 seconds during power up resets all parameters back to Factory Default.)
19 Primary Console Back Panel Thoratec CentriMagConsole LabelConsole SerialNumberDate ofManufactureEquipotentialBonding PostP1 PressureConnectorP2 PressureConnectorLabel – serial number – date of manufacture.Equipotential Bonding Post – Hospital Biomedical Engineer will use this for current leakage testing.Fuse CoverRS-232 Connector- for research purposesPower Entry Module – for Thoratec onlyAC power connector, flow probe connector, motor connector are the three ports you will be using when initiating support. The Console can be set up in less than 5 minutes.The Primary Console must be stored plugged in to main power to keep the battery charged.Pressure transducers and cables can be connected to the CentriMag Primary Console if desired. The console does not offer pressure alarms or auto control in response to pressure changes. Pressure transducer cables are available from Thoratec.MotorConnectorFlow ProbeConnectorAC PowerConnectorRS-232Connector(ThoratecUse Only)
20 Alerts and AlarmsMost common alert would be “flow below minimum”. This alert can be set by the clinician and should be set at approximately ½ liter below the desirable flow for your patient. The causes for “flow below minimum” could be:Hypovolemia from bleeding and/or fluid shiftsRight heart failure if only an LVAD implanted.Tamponade affecting the blood return to the heart or causing the inflow cannulae to be compromised.Other than that alert, the other alarms and alerts are rarely seen.[Review the laminated alarms and alerts at this point]Since several of the action steps include switching to a back up system, let’s review that now.
21 Flow Probe Reusable, non-patient contacting ultrasonic Flow Probe Can detect flows from LPMNot necessary to calibrate or zero the probeCan detect retrograde flow of >40 cc/min which is displayed as dashes “----“ instead of LPM on the consoleA disconnected or malfunctioning probe will display blank spaces “ “ instead of LPM on the consoleCompatible with 3/8” ID by 3/32” wall tubing¼” model also availableMolded clip-on designRead slide.Additional points: not necessary to use gels.is zeroed automatically each time the console is turned on. Not necessary to calibrate or zero the probe.
22 Inserting Blood Pump into Motor Once the pump is primed and ready to useinsert the pump into the motorRead slide.Incorrect pump mount can lead to hemolysis and thrombus formation.Match the groove on the Pump with one on the motor.Rotate counterclockwise until the Pump locks into place.Thread the retaining screw clockwise to secure in place.
23 Incorrectly Mounted Blood Pump Problem: Pump was not rotated counter-clockwise thus the retaining screw was advanced into the side of the pump.The screw should have been advanced into one of the four notches on the pump.If the pump is not correctly positioned and is not locked into the motor mount. The retaining screw has been advanced into the side of the pump, not into a retaining notch.The pump can come out of the mount if bumped and the pump is operating in an off-center position that is not safe.If this occurs you must reposition the pump You do not need to stop the pump to do this.To reposition the pump place hand firmly on the pump, loosen the retaining screw with 6 full turns of the screw, rotate the blood pump counter-clockwise 7º, to lock the pump into mount, and advance retaining screw to secure.Check that the retaining screw has advanced into one of the four notches on the side of the pump.It is not necessary to stop the pump to reposition it within the motor
24 CentriMag Back up Console Icons show which power source is being used, mains or battery.In the window:The top row includes info about set speed / actual speed and “Battery Time Remaining.”The second row contains information about alarm and alert status. On this example, “motor disconnected” is the first of two alarms. See page 51 for a list of alarms and alerts.If the alert condition persists for more than 60 seconds after the alert has been acknowledged, the audio alert tone reactivates and continues until acknowledgement except for ON BATTERY and LOW BATTERY (audio reactivates every 10 minutes for LOW BATTERY and every 15 minutes for ON BATTERY or until reconnected to AC power). The BATTERY BELOW MINIMUM message will activate with only 10 minutes of battery life left, and cannot be silenced until the battery is depleted or AC power is reattached to the Back-Up Console.No messages are displayed for POWER ON TEST FAIL or SYSTEM FAULT. The screen goes blank and the audiotone is activated.The five keypad buttons will be discussed on the next slide.Provides temporary basic life-support when a Primary Console is not availableThe Back-Up Console does not have flow and pressure sensing capability
26 Back-up Console Battery Module Read chemistry, available time, shelf life and rechargeable.Non-rechargeable – longer shelf life, lower cost, storage capacity,
27 CentriMag Back-Up Console Estimating Battery Time AvailableIf operating on AC power – Estimate is based on use at 3 LPM, 5500 RPM or the last condition while the system was operational on battery power.If operating on Battery power – Estimate is based on actual battery usage. Will vary with pump speed and changes in blood pressure and flow.Read first paragraph – on AC power the available battery time is an estimate.Read second paragraph – if using the battery then the available battery time is more accurate.Operating on AC PowerWhen the Back-Up Console is initially turned ON and is on Mains Power, an estimate of the remaining battery time is automatically displayed. The estimated time is representative of how long the system is capable of running on batteries under nominal operating conditions (5.5 lpm at 3,500 RPM). The displayed time will range from 10 to 299 minutes. The estimate will not vary while operating on Mains Power; it is only intended to serve as a means to guide the user regarding the typical length of battery time available should the system be operated under nominal conditions.If the system has been operating on batteries and is switched over to Mains power, the displayed time reflects the battery remaining time based on the last operating condition while the system was operated on batteries. This estimate is intended to provide a more precise prediction of battery remaining time relative to the most recent operating condition associated with supporting the patient.Operating ON Battery PowerIf the Motor speed is adjusted by the user when operating on batteries, sensors within the system detect the new operating condition via a change in Motor current which leads to an update of the estimated time remaining on batteries. When the speed is altered, the display informs the user that the unit is CALCULATING (“Calc”) the change in Battery Time Remaining. The calculation requires approximately one minute from the time the speed has been changed. Similarly, the system automatically detects a change in current when the physiologic conditions change, such as following a change in pressure, leading to an update in time remaining on batteries. This estimate is based on averaged data taken over 10 second intervals. As a result, the estimated time remaining on batteries will fluctuate dependent on the speed and change in physiologic conditions. Significant changes in speed will have a marked impact on remaining time on batteries. The rationale for informing the user that the system is calculating the remaining battery time is to urge the user to reexamine the displayed time after implementing a change and not to rely on the previous estimates.
28 Replacing Battery Module Insert one of the Battery Modules into the Battery Module compartment.Secure the Module by tightening the two retaining screws clockwise.Verify the Battery Module is fully seated by attempting to pull the module outward.Read Slide.(Do not attempt to replace the Battery Module when the Back-Up Console is powered with battery power. The Battery Module may only be replaced when the Back-Up Console is powered with AC power or when Console is OFF. If AC power is not available the Back-Up Console must be turned OFF, the circuit clamped to prevent retrograde flow, the battery replaced, the Back-Up Console turned back on, and flow resumed.)
29 Back-Up Console Battery Battery shelf life is not affected if a Battery Module is partially discharged and the Back-Up Console is returned back to storage awaiting next use.The reliability of the estimated battery life information that is displayed on the Back-Up Console does not change with removal and reinsertion of the battery module.The Backup Console Battery should be replaced when remaining battery life is less than one hour.WARNINGThe Back-Up Console battery is not rechargeable, and will deplete its charge if the Back-Up Console is not operated with AC power. Always check the remaining battery time available upon powering-up the Back-Up Console.Read the slide.Battery shelf life is not affected if a Battery Module is partially discharged and the Back-Up Console is returned back to storage awaiting next use.The reliability of the estimated battery life information that is displayed on the Back-Up Console does not change with removal and reinsertion of the battery module.The Backup Console Battery should be replaced when remaining battery life is less than one hour.
30 Back-up Console Battery Module ChemistryAlkaline ManganeseVoltage31.5 VoltsAvailable time2 hours at 5500 RPM, 3 LPMDimensionsHt: 8 cm , Width: 17 cm , Depth: 16 cmOperating temp-20°C to 54°C or -4°F to 130°FStorage temp-30°C to 35°C or -22°F to 95°FShelf life24 monthsRechargeableNo, Non-rechargeableDisposalReturn to Thoratec or dispose in compliance with local lawsRead chemistry, available time, shelf life and rechargeable.Non-rechargeable – longer shelf life, lower cost, storage capacity,
31 Inserting Battery Module Insert one of the Battery Modules into the Battery Module compartment.Secure the Module by tightening the two retaining screws clockwise.Verify the Battery Module is fully seated by attempting to pull the module outward.Read Slide.(Do not attempt to replace the Battery Module when the Back-Up Console is powered with battery power. The Battery Module may only be replaced when the Back-Up Console is powered with AC power or when Console is OFF. If AC power is not available the Back-Up Console must be turned OFF, the circuit clamped to prevent retrograde flow, the battery replaced, the Back-Up Console turned back on, and flow resumed.)
32 Back-Up Console Battery WARNINGThe Back-Up Console battery is not rechargeable, and will deplete its charge if the Back-Up Console is not operated with AC power. Always check the remaining battery time available upon powering-up the Back-Up Console.Read the slide.Battery shelf life is not affected if a Battery Module is partially discharged and the Back-Up Console is returned back to storage awaiting next use.The reliability of the estimated battery life information that is displayed on the Back-Up Console does not change with removal and reinsertion of the battery module.The Backup Console Battery should be replaced when remaining battery life is less than one hour.
34 Pump Circuit Flow Probe Drainage (Inflow) cannula Return (Outflow) CannulaVery simplified drawing of the completed VAD circuit. Refrain from including stop-cocks, ports, transducers in line because they can increase risk of air embolization and thrombus formation.
35 O.R. Equipment for Single Pump Implant Primary Console with MotorBack-up Console with MotorFlow Probe2 Complete systems (equipment and disposables) and 2 tubing clamp should always be available and in the direct vicinity of the patient during support.The spare console should be plugged in to maintain battery charge and powered ON ready for usePrimary Console may be substituted for a back-up console if desired.
36 O.R. Supplies - Single Pump Implant (1) Blood pump plus (1) spare(2) Tubing, 3/8 in ID x 3/32 in wall, 4 foot length(1) Inlet cannula(1) Outlet cannulae(2) Connectors, 3/8 in straightSterile tubing clamps and scissorsHeparin (10,000 u/L soln) and normal saline or pump primeBulb syringePledgets and sutures for atria or ventricle.Optional 8mm preclotted Dacron graft for return cannulationOne blood pump plus one spareTwo Medtronic Intersept® 3/8 X 3/32 inch 4’ sterile tubing sets (Model 3504)One inlet cannula – to be discussed on next slideOne outlet cannula – to be discussed on next slideTwo tubing interconnector (Medtronic Intersept® 3/8 X 3/8 inch (9.5 X 9.5 mm) Sterile Straight Barbed Connector without Luer Lock (Model 6023)Sterile tubing clamps and scissorsHeparin 10,000 u/L solution and normal saline or pump primeBulb syringe to fill connectors during mating of cannulae and tubingPledgets and sutures of choice for atria or ventriclePossibly an 8mm tubular Dacron graft
37 Recommended Cannulae Trans Thoracic Cannulae Venous Cannulae Edwards TFM032LSingle stage malleable venous cannula, 32 Fr. (10.7mm), 40 cm (16”)Edwards TFM036LSingle stage malleable venous cannula, 36 Fr. (12mm), 40 cm (16”)Arterial CannulaeMedtronic EOPA 77522EOPA Arterial cannula, blunt tip introducer without guidewire, 22 Fr, 30.5cmMeditronic EOPA 77722Same as but with dilator tip introducer and guidewireRead the slideThese cannulae are packaged with the clinical trial VAS kit and have proven flow characteristics. If you wish to use other cannulae, strive for cannulae with the same french size and similar characteristics. See next slide.
38 Ideal Cannulae Characteristics Cannulae SelectionIdeal Cannulae CharacteristicsWire reinforcedSingle stage lighthouse tip inflowLow resistance, versatile outflowMalleable inflow is desirableInflow circuit resistance should be much less than outflow circuit resistanceThe clinical trial cannulae have proven to be excellent cannulae.If using alternate cannulae, strive for the same characteristicsRead words in red type.(If inflow resistance is higher than outflow resistance, the potential for cavitation and out gassing)
40 Left Atrial Cannulation Cannulate wall of Left AtriumCannulate between RSPV & RIPVUse two buttressed concentric purse- string suturesCannulation is accomplished using a 32FR inflow placed in the posterior wall of the left atrium at the intra-atrial groove between the inferior and superior pulmonary veins.Use two buttressed concentric purse-string sutures.Adapted from Richenbacher W: Mechanical Circulatory Support, 1999
43 Circuit Priming Circuit Priming What works for your hospital? On the field or off the field?What method is used currently in your OR for priming a centrifugal pump circuit?
44 Priming & Deairing Two recommended techniques Closed Bag System for Centrifugal PumpPre-assembled circuit (Medtronic)Ability to recirculateSubmersion techniqueUnassembled tubingMust assemble within sterile fieldMedtronic Prime Pack p/n 5G91R2
45 Priming Pack for Closed Bag System VenousLineArterialLineAvailable from MedtronicOrder P/N 5G91R1See OR Checklist for IFUsPrimingLine
46 Sterile technique must be observed Submersion TechniqueSubmersion Technique (STERILE TECHNIQUE MUST BE OBSERVED!)Sterile technique utilizedFill large sterile basin with 3L warm injectable .9NSSlowly submerge one end of 4 ft. tubing into basin and gradually submerge entire piece in circular motion creating a siphon allowing tubing to fill completely with injectate gradually from end to the other. Clamp both ends of tubing upon completion of de-airing.Repeat step 2 for 2nd piece of 4 ft. tubingOpen Centrimag pumpSubmerge CMAG pump in sterile basin, rotate side to side, and ensure complete removal of all air and air bubbles.With pump and tubing completely submerged, release one tubing clamp and connect to inlet barb of pump.Repeat step 6 with 2nd piece of tubing, attaching it to outflow barb of pump.Visually inspect pump and tubing to ensure complete de-airing.Sterile technique must be observed
47 Submersion Technique (cont.) Submersion Technique (STERILE TECHNIQUE MUST BE OBSERVED!)Sterile technique utilizedFill large sterile basin with 3L warm injectable .9NSSlowly submerge one end of 4 ft. tubing into basin and gradually submerge entire piece in circular motion creating a siphon allowing tubing to fill completely with injectate gradually from end to the other. Clamp both ends of tubing upon completion of de-airing.Repeat step 2 for 2nd piece of 4 ft. tubingOpen Centrimag pumpSubmerge CMAG pump in sterile basin, rotate side to side, and ensure complete removal of all air and air bubbles.With pump and tubing completely submerged, release one tubing clamp and connect to inlet barb of pump.Repeat step 6 with 2nd piece of tubing, attaching it to outflow barb of pump.Visually inspect pump and tubing to ensure complete de-airing.Sterile technique must be observed
48 Circuit De-Airing Suggestions Prime with warm NS, not bloodRecirculate the prime solution, if possibleDo not use connectors with Leur portsDo not hit or strike blood pump to de-airUse large bubble in pump to collect smallSlowly add fluid while making final connectionAlternatively, gently squeeze tubing to eject air while making final connectionThese suggestions represent STANDARD CPB DE-AIRING TECHNIQUES”Read Slide
49 Console Set Up Ensure Console is connected to AC power. Console should always be stored connected to AC powerConnect Motor drive and Flow probe to back of consoleTurn on power to console via switch on side panelCheck Power Status – verify green AC power on indicator is illuminatedRead slide
50 Console Power Up Self Test When Power is turned on, the Self-Test procedure will initiate automatically.If ‘POWER ON TEST FAIL’ is displayed – Immediately turn OFF the console and then turn back on. If the console does not pass the second self test, REPLACE CONSOLE.When all Self-tests are completed successfully the “INITIALIZATION COMPLETE” message will appear briefly, then “MENU” and “SET RPM” are displayed – indicating the console is ready for use.The console performs a self test each time it is turned on.Read slide.
51 Console Start UpEnsure that circuit is primed & de-aired, and that Heart is full prior to initiating supportConnect Flow Probe to Blood Pump Outlet tubing - ensure arrow is aligned in direction of flow.Start the blood pump by depressing the SET RPM keypad. Remove clamp when RPM above Observe circuit to insure forward flow.Depress the INCREASE arrow until the flow rate is at the required level.The flow is adjusted by depressing the SET RPM keypad and then using the INC/DEC arrows to increase or decrease flow.Connect the flow probe to the tubing ensuring the arrow is aligned in the direction of flow. Do not damage the pump outlet port by placing the probe too close.To start the Blood Pump, perform the following steps:1. Depress the SET RPM keypad. SET PUMP SPEED = 0000 RPM will be displayed. Depress the INCREASE keypad while slowly unclamping the outlet tubing until the flow rate is at the desired level.2. Remove the tubing clamp from the circuit at approximately 1,000 RPM. Operator must observe the circuit to insure forward flow. If 1000 RPM is not adequate to overcome systemic pressure, reclamp and increase RPM slightly.Increase the RPM to desired Blood Pump flow.The Pump outlet tubing MUST be clamped whenever the Pump is OFF, if the Pump speed is insufficient to overcome arterial pressure, or when the RPM is set to below 1000 RPM – the Flow Probe will detect retrograde flow and cause a Flow Below Minimum alarm.
53 Anesthesia Considerations Heart failure patient versus a simple failure to wean from cardiopulmonary bypassPharmacologic Considerations – ACE inhibitors and amiodarone, impaired renal or hepatic functionPreop Assessment – assess degree of organ failureLining and induction – large bore IV and radial arterial line before induction and after induction TEE, Swan-Ganz and maybe a second central line for rapid volume infusionExcellent reference is a book chapter on anesthesia from Cardiac Assist Devices, Goldstein, Oz. Futura PublishingSome of the points discussed are:HF and post cardiotomy patients are differentAnesthesiologist should be aware of the potential for adverse reactions when heart failure patients who are taking ace inhibitors and/or Amiodarone are subjected to surgical stress and anesthesia.(Read last two points)
54 Separation from CPBFirst check for PFO, aortic insufficiency and left ventricle decompression with TEEInotropes and afterload reduction for right heartPrevent air entrainmentBalance coming off CPB with going on CentriMag. Keep atria or ventricle full enough to not pull air through suture lines.Avoid air in venous & arterial linesInsure adequate blood productsIf surgeon manipulates heart to stop bleeders – COMMUNICATE. Perfusion should slow or stop CentriMagCompletely reverse HeparinAfter the completion of inflow and outflow cannula placement, preparations are made to separate from cardiopulmonary bypass.To prevent air entrainment, use caution when opening a central line using a CentriMag for right-sided support.Read Slide
55 Transesophageal Echo Pre-bypass – Aortic valve and PFO During bypass – Assess inflow cannula placement.Initiation of support – Assess volume status & detect air.Post-bypass – monitors right ventricular function and left heart decompression. Septum in neutral position.Warning - Left atrial or ventricular collapse with resulting inlet cannula occlusion can lead to air entrainment and stop the pump.The information gained from TEE includes:Read Slide
56 O.R. Potential Complications }Right ventricular dysfunctionLow flow/ Inflow obstructionAir entrainment / embolismIncreased pulmonary vascular resistanceCannulae selection, position and stabilityPFO and systemic desaturationBleeding (cannulation & other sites)Similar to other devicesOften RelatedIn the O.R. , the most common complications are the items highlighted in red. There is an interrelationship between the three. Right ventricular dysfunction may lead to a low flow state on the left side. This in turn may lead to atrial collapse, suction, and air entrainment.
57 Prevention of Air Entrainment When initiating support:Partially inflate lungs prior to separation from CPBPlace patient in Trendelenburg positionMonitor aorta for air with TEEFill chest with warm normal saline or CO2Increase RPM very slowlyInsure adequate volume in heart chamber when coming off cardiopulmonary bypassWatch circuit and use clamp to prevent air from entering blood pumpAs with any centrifugal pump, air can be sucked into the circuit and pumped to the body. Transitioning from CPB onto CentriMag support is a particularly vulnerable time because atrial or ventricular suture lines have not yet been tested, air could be hidden in the heart or trapped in the pulmonary veins, vents could be accidentally left in place. Precautions should be taken by the surgical team to mitigate these situations. Additionally, [read the slide]
58 Prevention of Air Entrainment During SupportMonitor blood volume with TEE &/or PressuresMaintain atrial pressures 10–15 mm Hg in the O.R.Under perfuse while the chest is openEncourage the use of ventricular cannulationEncourage the use of biventricular supportReduce RPM for any indication of inadequate volumeReduce RPM for manipulation of the heartReduce RPM for movement of the patientMonitor tubing for “chatter” & be prepared to respondAs soon as possible set the low flow alarmReduce flow when inflating lungsTo prevent air entrainment once the patient is off CPB and now completely supported by the CentriMag:Maintain atrial pressures between 10 and 15 mmHgCOMMUNICATION required between surgeons and person at the CentriMag Console so the RPMs can be reduced during manipulation of the heart. It is possible that for extreme manipulation the pump should be stopped and tubing clamped to prevent air entrainment.Reduce flow
59 IABP Considerations May provide pulsatile perfusion Under inflate balloon to reduce pump afterloadPull back sheath to improve distal perfusionMonitor distal limb perfusion at least hourlyIf balloon is to be removed:In O.R. with Femstop or cutdown repairIn ICU after coagulation parameters have normalizedIf pulsatile flow is desired, an IABP can be used to achieve it.Read Slide
60 CPS Oxygenator may be added to circuit Provides pulmonary support Negates need for sternotomyLess cardiac unloadingOccasionally CentriMag is used for Cardiopulmonary support for pulmonary pathology, emergent cardiac support or if a sternotomy is to be avoided.Since flow is determined by the size of the cannulae and percutaneous or peripherally inserted CPS cannula are smaller than transthoracic cannula, flow is decreased therefore there is less cardiac unloading.
61 Percutaneous Cannulation Generally Femoral vein to Femoral arteryIn adults Fr venous drainage cannula and Fr arterial return cannula5Fr distal arterial cannulaGenerally the inflow is from the femoral vein with outflow to the femoral artery.The drainage cannula is usually Fr and the return cannula is Fr. As a general rule, the inflow (venous) cannula should be 2 french sizes larger than outflow cannula.A 5 Fr distal arterial cannula can be used to perfuse the leg distal to the insertion site.
63 Circuit w/ Oxygenator Venous (Inflow)cannula CentriMag pumpFlow probeHere is an example of an CPS circuit. The venous cannula drains to the pump, the oxygenator is spliced in after the pump, the flow probe is distal to the oxygenator and the blood is returned to the artery.Almost all oxygenators have ports for monitoring pressure. This is the preferred method for measuring pressure gradient, as opposed to measuring pressure before the pump.Arterial (Outflow) cannula
64 Emergency Switch to Back-up System Today each of you should practice switching to a back up system. This laminated sheet will be attached to the cart for your review.Clamp outflow tubing. Do not clamp the tubing before the pump as this might draw air into the blood.Use the red soft key to stop the pumpTurn the set screw counter clockwise all the way out. It is engineered to not come out of the motor so it will not fall on the floor.Turn the pump 7 degrees clockwise to line up the notches on the pump with the tabs on the motor.Pull the pump out of the motor and place into the back up motor again aligning the notches and tabs.Turn the pump 7 degrees counter-clockwise to align the set screw and a notch in the pump.Be very sure the set screw is aligned with a notch and then hand tighten the screw.Increase the RPMs on the Back Up Console to 1000 and then remove the clamp.Increase the RPMs to the previous setting.RPM > 1000
66 Routine Patient CareRoutine patient care for patients on the CentriMag Blood Pump is similar to that for patients on other type of extracorporeal support.Many patients are fully sedated and on ventilatory support.Read Slide+Conscious patients may require sedation if they are non-compliant, to prevent cannulae movement or bleeding
67 Normal Operating Conditions Pump Speed : – 4000 RPMPump Flow(s): 4 – 5 LPMRAP / LAP: 10 – 15 mm HgTarget ACTVolume status, cannulae size & tubing length will affect pump flows. These are only guidelines for an ADULT patient.
68 Management Points CentriMag system has no auto-control Adjustments in flow must be gradualAvoid conditions that result in line “chatter”Avoid flexing of tubing near the connectorsBalance left & right filling pressures not flowsForces are easily transmitted through tubingAuto Control – All adjustments in RPM/Flow must be made by the operator.Increase/Decrease RPM no faster than 100 RPM/sec. This allows the vasculature to adjust to the different flows. This pump is very efficient and responds immediately to operator adjustmentsAny increase in RPM MUST be accompanied by a corresponding increase in flow. If this does not occur, reduction in RPM may be necessary. Reasons could include:HypovolemiaCannulae obstructionCannulae malpositionRV failure after LVADTamponadeArrhythmiaAll the conditions listed above may cause line chatter. If line chatter occurs, reduce RPM and resolve underlying condition.Avoid flex of tubing to prevent dislodgement of fibrin deposition.Utilize TEE to balance filling pressures.Forces are easily transmitted through tubing. Potential complications are decannulation and exsanguination. Use caution when moving patient or pump.
69 Anticoagulation Guidelines* (If no CPB) Full anticoagulation (ACT ~ 300) is essential prior to cannulae insertionMaintain heparin infusion if CT drainage < 50 ml/hrWhen pump flow is sufficient, target ACT 160 – 180 (PTT times normal)*Anticoagulation needs vary per patientIf CentriMag support is initiated without the use of CPB, full anticoagulation is essential prior to/during/immediately after cannulation. Administer heparin prior to cannulation and continue without interruption. Heparin levels can be allowed to drift down when flow through the cannulae is sufficient.
70 Anticoagulation Guidelines*(with CPB) Achieve optimal CentriMag flow then reverse heparinStart heparin infusion when CT < 50 ml/hr for 2-3 hoursTarget ACTTarget PTT times normal*Anticoagulation needs vary per patientIf anticoagulation is required within the six-hour window of support, use these guidelines as appropriate.
71 Once Every ShiftMove each flow probe about 1 cm every 8-12 hours. Rotating areas of the tubing will reduce indentations and the risk of blood clot formation.Inspect tubing and connectors for white ring thrombus or red blood clots. Both are easier to see with the light of a “good” flashlight. What you see in areas where clots may be beginning to form is like a shooting star. Report all clots and white rings. Blot clots may indicate a need to adjust anticoagulation.
74 Fluid BalanceIt is essential for safe device operation that the LV (or LA if atrial cannulation) is supplied with sufficient volume.Adequate fluid balance should be checked by monitoring CVP, LA pressure or wedge pressure if available, and careful monitoring of fluid input/output balanceAn increase in RPM should always cause an increase in flow – if this does not occur reduce RPM until changes in flow do occur. Leave set approx. 1 LPM lower.Read slide.
75 Patient Management Bleeding Perioperative nutrition Tamponade ArrhythmiasVariable volumeVariable device flowPulmonary dysfunctionRight ventricular failurePatient management issues are similar to other life support technologies. For perioperative nutrition, refer the Advanced Practice Guidelines for HeartMate XVE.
76 Defibrillation / Cardioversion It is recommended that the CentriMag pump be stopped and removed from the Motor before defibrillation.If the patient’s condition does not permit stopping the pump, cardioversion may be performed with the pump running.If CentriMag used as right heart support with a long term LVAD, consult LVAD instructions for use. If LVAD must be stopped before defibrillation, then CentriMag RVAD must be stopped as well.Read slideIf CentriMag is used as an right-heart support with an LVAD that needs to be stopped during cardioversion, the CentriMag must also be clamped (outflow) and stopped.
77 Perioperative Complications Most commonLow flowRare but has occurredHigh RPMHemolysisIncorrect pump mountConsole or Motor failureThrombus in atria or ventricleThese are complications most often experienced in the ICU.Low flow most often the result of hypovolemia, right heart failure, tamponade, cannulae obstruction, arrhythmiaHigh RPM refers to manual increase in RPMs without corresponding increase in flow. May be caused by inflow obstruction, cannulae too small, cannulae malposition, kinked tubing.
78 Response to Complications Low flow – ↓ RPM, Identify cause.Thrombus on connectors – Precautions to avoid tubing flex or abrupt flow changes.High RPM -↓ RPM, Identify cause.Hemolysis -↓ RPM, Identify cause.Incorrect mount – Correctly mount.Console or Motor failure – To Backup.Thrombus in atria or ventricle – Assess stability, Avoid conditions that will dislodge, ↑ Anticoagulation.Decreasing RPM in response to a low flow condition is primarily intended to prevent suction/air entrainment or other complications. To correct a low flow issue often requires the administration of fluid,or treatment of right heart dysfunction tamponade, arrhythmias, elevated PVR, etc.When thrombus is detected on connectors, avoid abrupt flow changes caused by suction events or clamping of tubing.
79 Frequent System Checks Activated Clotting Time (ACT) within target range?Line chattering or shaking?Record pump flow and RPM with vital signsRead Slide
80 Kinking and Cavitation Prevent all kinking of tubes.May require utilization of support techniques to prevent kinking.Twill tape½ inch tubingKinking of tubing may cause cavitation.
81 Periodic System Checks Move flow probe ~1 cmTubing secured to patient?Tubing bends wide and smooth?On AC power and battery fully charged?Air circulation around motor & console?Two tubing clamps near each blood pump?Backup console ready with battery life > 60 min?Low flow alarm set 1.0 LPM less than target?Review “Emergency Switch to Backup” ref. cardPractice pump “Switch” with the backup consoleFlow probe must be moved to prevent indentation of the line.Is the tubing adequately secured to patient?Short tubing length cut longitudinally can be used to stent tubing at pump connections to prevent kinking. Additionally, the bends in the tubing between the cannulae and the pump should be wide to prevent turbulent flow.Motor is cooled by air flow. Do not cover. It is normal for the motor to become warm to touch.
82 Battery Maintenance Primary Console only Recalibrates fuel gauge to batteryMust be performed every 6 months or when the Primary Console displays “Battery Maintenance Required” alertLeaving Primary Console unplugged for extended period (weeks) will lead to “Battery Maintenance Required” alert
83 Battery Maintenance Procedure Required equipmentAffected Primary ConsoleMotorFlow ProbeTraining LoopPlug Motor into Primary ConsoleFill Training Loop with water and insert training loop pump into MotorAttach flow probe to outlet tubing and plug into Primary Console
84 Battery Maintenance Procedure (cont.) Turn on Primary ConsoleStart pump and turn to maximum RPM (5500 & 9.5 lpm)Unplug Primary Console from AC power and run on battery power until pump stops (approx. 1 hour)After pump stops but before the display goes completely blank, turn off console and plug in to AC powerCharge for at least 5 hours
85 Emergency Switch to Back-up System Today each of you should practice switching to a back up system. This laminated sheet will be attached to the cart for your review.Clamp outflow tubing. Do not clamp the tubing before the pump as this might draw air into the blood.Use the red soft key to stop the pumpTurn the set screw counter clockwise all the way out. It is engineered to not come out of the motor so it will not fall on the floor.Turn the pump 7 degrees clockwise to line up the notches on the pump with the tabs on the motor.Pull the pump out of the motor and place into the back up motor again aligning the notches and tabs.Turn the pump 7 degrees counter-clockwise to align the set screw and a notch in the pump.Be very sure the set screw is aligned with a notch and then hand tighten the screw.Increase the RPMs on the Back Up Console to 1000 and then remove the clamp.Increase the RPMs to the previous setting.RPM > 1000
86 Review Questions Expected battery life for each console? Action to take for low flow or line shaking?Target CVP? Must L. and R. flow be equal?At what value should the flow alarm be set?Indicator that the pump is mounted correctly?Backup items required with patient at all times?Answers:Primary 1 hour/ Back-up 2 hoursDecrease RPM, then assess underlying problem. Problems may include:HypovolemiaCannulae obstructionCannulae malpositionRV failure after LVADTamponadeArrhythmia3. CVP ~ 10. No, in fact the right side flow will likely be lower than the left.4. 1 LPM below target flow5. The set screw is in the groove6. Fully connected Back-up Console & Motor, tubing clamps
88 In the air / On the roadCentriMag patients being transported
89 CentriMag® Transport Capabilities Air or ground transportLeft, right, or biventricularMay include oxygenatorPediatric or adult capabilityThree hour total battery capacity with 1 Primary + 1 Back-upBattery capacity is Primary + back-up.If additional battery time is required, additional back-up batteries can be packed.
90 CentriMag Power Conditioning Unit CentriMag is FAA approved for air transportWhen operating on AC power and connected to aircraft UPS, CentriMag consoles must be plugged into a Power Conditioning Unit (PCU) to filter electrical noise that could otherwise interfere with avionics.When operating on battery power, no electrical line noise is generated so PCU is not required.PCU can accommodate up to 4 CentriMag consoles at one time and is reusable.FAA recognizes an international testing standard: RTCA DO-160FRTCA DO-160F - Standard procedures and environmental test criteria for testing airborne equipment for the entire spectrum of aircraft from light general aviation aircraft and helicopters through the "Jumbo Jets" and SST categories of aircraft.CentriMag passed RTCA DO-160F when used with Power Conditioning Unit.
91 Patient Movement & Transport Risk of decannulation is greater during transport of the patientContinuously monitor patient’s hemodynamics and pump flowsAssign one individual to monitor consoles and blood pumpsPlace blood pump and motor on the bed between the patients legsInsure pumps are not coveredBackup console and clamps must always be with the patientThe Primary Console has approximately 1 hr of battery power and a Back Up Console has 2 hrs of battery powerRead the slide.
92 Transport General Concepts Identify receiving center in advance (hub)Three protocols (spoke, transport, hub)Preposition equipment and suppliesTrain and conduct dress rehearsalsAdapt current transport protocolsExisting protocols for IABP, CPS, ventilator-dependent patient transport may serve as useful templates for CentriMag protocol.
93 To Include in Transport Protocol Equipment and supplies neededIndividuals and responsibilitiesPrimary and backup power sourcesResponse to most likely complicationsSecuring of equipment during transportRead Slide
94 Transport Tips Assign one individual to monitor system Decannulation can occur during transportMonitor pressures & flow continuouslyPlace blood pumps and motors on the bed between the patient’s legs if intra-hospitalBlood pumps secured to stretcher for inter-hospital transport.Back-Up Console and clamps must be availablePrimary Console has approximately 1 hr powerRead Slide
97 Review Questions Expected battery life for each console? Action to take for low flow or line shaking?Target CVP? Must L. and R. flow be equal?At what value should the flow alarm be set?Indicator that the pump is mounted correctly?Backup items required with patient at all times?Answers:Primary 1 hour/ Back-up 2 hoursDecrease RPM, then assess underlying problem. Problems may include:HypovolemiaCannulae obstructionCannulae malpositionRV failure after LVADTamponadeArrhythmia3. CVP ~ 10. No, in fact the right side flow will likely be lower than the left.4. 1 LPM below target flow5. The set screw is in the groove6. Fully connected Back-up Console & Motor, tubing clamps
98 CentriMag Training Review What are the three components of the CentriMag system?What is the priming volume of the CentriMag pump?What are the max CentriMag pump speed and flow?Is it necessary to calibrate the flow probe before operating the system?Blood Pump, Motor, Console31cc5500 RPM & 9.9 lpmNo
99 CentriMag Training Review 5. How must the Primary Console be stored when not in use?6. When starting the blood pump, the outflow must remain clamped until RPMs are above ________?7. The back-up battery provides _____ hours of support at 3500 RPM?8. Is the back-up battery rechargeable?5. Plugged inor until forward flow is observed7. 28. No, but it is replaceable
100 CentriMag Training Review 9. Describe the emergency switch to back-up procedure.10. Which should have a larger I.D., the inflow cannulae or outflow?11. Name the two methods for priming and deairing.12. Name the three most common O.R. potential complications.9. Clamp outflow. Reduce RPM to zero. Unlock pump. Remove pump. Switch to back-up motor. Rotate pump. Lock pump. Increase RPM to Unclamp outflow.10. Inflow should be larger 32-36F vs. outflow of 22-24F11. Closed Bag System and Submersion technique12. Right ventricular dysfunction, low flow/inflow obstruction, air entrainment/embolism
101 CentriMag Training Review 13. Any increase in RPM must be accompanied by an increase in _____?14. If line chatter is observed, immediately do this?15. During cardioversion, is it necessary to stop the CentriMag?16. What is the target ACT range post-op?13. Flow14. Reduce pump speed until chatter resolves15. Not unless the patient also has an implanted LVAD that is required to be stoppedto 180 (PTT 1.5 – 1.8)
102 CentriMag Training Review 17. What is the target CVP?18. Must L. and R. flows be equal?19. At what value should the flow alarm be set?20. What are the backup items required with the patient at all times?17. Around 1018. No, in fact right side flow will likely be lower than left19. 1 lpm above target flow20. Fully connected back-up console, motor, and tubing clamps.