Intra-aortic Balloon Pump
NLC CCT PROGRAM Why IABP?
▪ CO = SV x HR. What is SV? ▪ Stroke Volume made up of 3 components: ▪ Preload ▪ Contractility ▪ Afterload Why IABP?
▪ IABP to reduce afterload ▪ Increases coronary artery blood flow IABP: Intra-aortic balloon pump
IABP is typically used for the following situations: ▪ During severe angina episodes ▪ Before, during, or after open-heart surgery (in certain patients only) ▪ Before, during, or after balloon angioplasty (in certain patients only) ▪ During emergency situations, including heart attack and congestive heart failure ▪ During the waiting period for a donor heart for heart transplantation
IABP
How does it work?
▪ Catheter inserted into the femoral artery ▪ Advanced until it sits just below the aorta arch and above the renal arteries. ▪ IABP catheter is attached to a balloon pump ▪ The machine pumps helium into the catheter, causing the balloon on the tip to inflate and deflate at specific times during a heart beat. ▪ It helps reduce the workload of the heart. Breakdown
▪ Due to rapid inflation (diastole) it causes augmentation of diastolic pressure ▪ Basically creating a 2nd pressure wave- perfuses heart better ▪ Rapid deflation of the balloon (right before ventricular contraction) drops the aortic pressure (space open from balloon) ▪ This reduces afterload (lv resistance)
▪ Most O2 demand used to create pressure. This lowers myocardial demand ▪ Increases SV, decreases HR ▪ Allows heart to “rest”, increases coronary artery and systemic blood flow, alters HF cycle improving metabolic abnormalities due to increase of renal flow also IABP
▪ The balloon is inflated during diastole in sync with the closure of the aortic valve. The blood in the aortic arch above the level of the balloon is pushed backward providing increased coronary artery blood flow and increased myocardial oxygen supply. IABP ▪ The balloon is deflated just before systole which helps to decrease afterload. The space where the balloon was inflated creates an empty space where the blood doesn't have to flow against any resistance. Waveforms Waveforms Waveforms Risks/problems
▪ Bleeding/hematoma at insertion site Manual pressure can be held w/ a 4x4. ▪ Migration of catheter- Moving the patient can cause the catheter to migrate, this may block blood flow to the renal arteries and can cause a decrease or stopping of urine output. Physician can reposition. Monitor UO hourly ▪ Loss of pulses to extremity-large catheter can cause blockage of blood flow, this is a major problem and can result in removal of the IABP. Pulse and circulation checks are important assessments. Doppling pulses if necessary.
Transporting
▪ When transporting a IABP it runs off of it’s internal battery or it can be plugged into your inverter in the rig. This would be optimal for long transports as the battery lasts approximately 120 minutes. ▪ The pump will have it’s EKG leads hooked up-if a lead comes off, the pump will stop. Some patients are very dependent on the pump and you will see immediate blood pressure issues. Tape the leads down! Transporting continued
▪ Patient with IABP are usually on a heparin drip, they have a higher risk for bleeding and their groin site needs to be checked regularly. ▪ The pump will also be connected to the arterial line from the groin. This waveform needs to be monitored also. It is important to keep the transducer even with the phlebostatic axis and zeroed in that position.
Transporting continued
▪ Helium leak alarm-tubing may be dislodged from the back of the machine. Place tubing back on and hit the auto-fill button on the front, restart. ▪ HOB must be positioned at less than 30 degrees. ▪ IABP can only be in the standby mode for 20 minutes, longer than that produces a big risk of clots for the patient, IABP needs to be removed. Machine monitors time in standby.
Transporting continued
▪ All equipment must be secured properly prior to transport. ▪ Position all you equipment so you can read the monitors easily. ▪ Ensure that your AC power is working correctly prior to leaving. ▪ Fixed Wing: the hypobaric environment in the aircraft can affect the pressures in the balloon. You may need to auto-fill the balloon when taking off, at cruising altitude, and when landing. Pressure bags transducers
▪ Arterial lines and SGC both use pressure bags with transducers. ▪ Level and zero for accurate numbers ▪ Tubing should be free of air bubbles. ▪ Some use NS, some heparinized saline
Arterial Pressure Waveform
▪ Dicrotic limb reaches from point (b) to point (c)
b
c Dicrotic limb
▪ Descending limb of the arterial pressure trace as the pressure falls to that of the end diastolic pressure ▪ Dicrotic means ‘twice beating’ – meaning that this phase of the arterial pressure pulse should have a second, smaller wave, known as the dicrotic notch Timing the IABP
▪ Scope of Practice ▪ Employer credentialing ▪ Maintaining skills/knowledge IABP
Timing the IABP
▪ Use either ECG or Art line (aortic valve closure=dicrotic notch) ▪ Determine time delay between R wave and dicrotic notch and enter value into device ▪ Turn it on, set frequency—many devices automated ▪ Watch print out for inflation and deflation IABP Timing
▪ Timing: Set the mode to 1:2 ▪ Compare the unassisted cardiac cycle with the assisted (augmented) cycle. ▪ There is a sharp “V” on the waveform ▪ at the dicrotic notch (DN). The dicrotic ▪ notch is when the aortic valve closes – this ▪ is the point at which the intra-aortic balloon ▪ starts to inflates.
▪ Inflation of the balloon is timed to occur at the dicrotic notch (aortic valve closure) on the arterial pressure tracing. ▪ As the balloon inflates and the pressure rises there will be an upward deflection following the dicrotic notch, referred to as diastolic augmentation and represents the pressure produced early in diastole by the inflated balloon.
C D F
B
A E
A= One complete cardiac cycle D= Diastolic augmentation B= Unassisted aortic end diastolic pressure E= Reduced aortic EDP C= Unassisted systolic pressure F= Reduced systolic pressure
IABP
IABP CONTROL PANEL Cardiac Arrest and IABP
▪ Cardiac Arrest/Defibrillation-If possible, use ECG or Pressure trigger during CPR. It will synchronize trigger to the rate and rhythm of chest compressions. When defib-the machine is completely isolated from the patient, however the operator should stand clear of the machine while debrillating. This is especially important during battery (ungrounded) operation-such as in transport. Normal Augmentation Timing Errors Timing Errors
Diastolic Augmentation
Unassisted Systole
Dicrotic Notch Early Inflation
▪ Inflation prior to aortic valve closure ▪ Waveform Characteristics ▪ Inflation prior to dicrotic notch ▪ Diastolic augmentation encroaches onto systole ▪ Physiologic Effects ▪ Possible premature closure of aortic valve ▪ Possible increase in afterload ▪ Aortic regurgitation ▪ Increased myocardial oxygen demand Timing Errors
Diastolic Augmentation
Dicrotic Notch Late Inflation
▪ Waveform Characteristics ▪ Inflation of IABP after dicrotic notch ▪ Absence of the sharp “V”
▪ Physiologic Effects ▪ Sub-optimal coronary artery perfusion Timing Errors
Diastolic Augmentation
Unassisted Early Deflation
▪ Waveform Characteristics ▪ Sharp drop after diastolic augmentation ▪ Aortic end-diastolic pressures same for assisted and unassisted ▪ Assisted systolic pressure may rise ▪ Physiologic Effects ▪ Sub-optimal coronary artery perfusion ▪ Possible retrograde blood flow ▪ Sub-optimal afterload reduction ▪ Increase in myocardial oxygen demand Timing Errors
Diastolic Augmentation
Unassisted Late Deflation
▪ Waveform Characteristics ▪ Rate in rise of systolic waveform delayed ▪ Diastolic augmentation wave widened ▪ Physiologic Effects ▪ No afterload reduction ▪ May actually increase afterload by impeding LV ejection ▪ Increases myocardial oxygen demand
Troubles
▪ What if we have to stop inflating the IABP catheter? ▪ What if the device battery fails and we have no power? ▪ What if we run out of Helium? ▪ What if the patient stops making urine? ▪ What if the patient loses leg pulse?