Intraaortic Balloon Pump Management
PREREQUISITE NURSING KNOWLEDGE
• Knowledge of the anatomy and physiology of the cardiovascular system is needed.
• Understanding of the principles of hemodynamic monitoring, electrophysiology, dysrhythmias, and coagulation is necessary.
• Clinical and technical competence related to the use of the intra-aortic balloon pump (IABP) is needed.
• Advanced cardiac life support knowledge and skills are necessary.
• Indications for IABP therapy are as follows:
Acute myocardial infarction (MI) complicated by left ventricular failure3,12,26,28
Recurrent ventricular dysrhythmias as a result of ischemia16
Support before, during, and after coronary artery bypass graft surgery2,29
Support before, during, and after coronary artery angioplasty or additional interventional cardiology procedures for patients at high risk4,11
Mechanical complications of acute MI, including aortic stenosis, mitral stenosis, mitral valvuloplasty, mitral insufficiency, ventricular septal defect, and left ventricular aneurysm
Intractable ventricular dysrhythmias13,18
Bridge to cardiac transplantation, ventricular assist devices, or total artificial hearts
Cardiac injury, including contusion and coronary artery tears
• Contraindications to IABP therapy are as follows:
• The relative value of IABP therapy in the presence of severe aortoiliac disease, major coagulopathies, and terminal disease should be evaluated individually.
• IABP therapy is an acute short-term therapy for patients with reversible left ventricular failure or an adjunct to other therapies for irreversible heart failure. Cardiac assistance with the IABP is performed to improve myocardial oxygen supply and reduce cardiac workload. Intra-aortic balloon (IAB) pumping is based on the principles of counterpulsation (Fig. 55-1).
• The events of the cardiac cycle provide the stimulus for balloon function, and the movement of helium gas between the balloon and the control console gas source produces inflation and deflation of the balloon.
• Recognition of the R wave or the QRS complex on the electrocardiogram (ECG) is the most commonly used trigger source.
• Inflation occurs during ventricular diastole and causes an increase in aortic pressure. This increased pressure displaces blood proximally to the coronary arteries and distally to the rest of the body. The result is an increase in myocardial oxygen supply and subsequent improvement in cardiac output.
• Deflation occurs just before ventricular systole or ejection, which decreases the pressure within the aortic root, reducing afterload and cardiac workload.
• Insertion and placement verification:
The IAB catheter is commonly placed in the femoral artery via percutaneous puncture or arteriotomy.
The IAB catheter can also be placed via a transthoracic approach.15
The IAB catheter lies approximately 2 cm inferior to the left subclavian artery and superior to the renal arteries. This position allows for maximum balloon effect without occlusion of other arterial supplies (Fig. 55-2).
Figure 55-2 Intra-aortic balloon positioned in the descending thoracic aorta, just below the left subclavian artery but above the renal artery. (From Quaal SJ: Comprehensive intraaortic balloon counterpulsation, ed 2, St Louis, 1993, Mosby.)
The IAB should not fully occlude the aorta during inflation. It should be 85% to 90% occlusive.
Fluoroscopy may be used to aid in IAB catheter positioning, especially for patients with a tortuous aorta.
Correct catheter position is verified via radiography if fluoroscopy is not used during catheter insertion. The visibility of the IAB catheter tip may be enhanced when the IABP is temporarily placed on standby (follow manufacturer’s guidelines).
The central lumen of many IAB catheters provides a means for monitoring aortic pressure.
Some IAB catheters use fiberoptic technology. These catheters have a fiberoptic sensor located at the tip of the IAB catheter. The sensor transmits the pressure signal to the IAB console.
• Timing methods of IABP therapy vary slightly from manufacturer to manufacturer. With the traditional or conventional method, the IAB deflates at the QRS complex, before isovolumetric contraction. The IAB also deflates at the QRS complex with the real-time method. An important principle of real timing is the duration of the balloon deflation during cardiac systole. During real timing, the IAB is timed to deflate at the onset of each QRS complex and to remain deflated throughout systole. A constant diastolic interval is not necessary for real timing.5,6,19,22
• The mechanics of the IABP control console vary from manufacturer to manufacturer.
• Specific information concerning controls, alarms, troubleshooting, and safety features is available from each manufacturer and should be read thoroughly by the nurse before use of the equipment.
EQUIPMENT
• ECG and arterial pressure monitoring supplies
• IAB catheter (size range, 7 Fr to 10 Fr for adults; balloon catheters vary in balloon volumes, 25 to 50 mL)
• Antiseptic solution (e.g., 2% chlorhexidine-based preparation)
• Caps, goggles or face shields, masks, sterile gowns, gloves, and drapes
• O-silk suture on a cutting needle or a sutureless securement device
• No. 11 scalpel, used for skin entry
• 1% Lidocaine without epinephrine, one 30-mL vial
• Stopcocks, one two-way and one three-way
• 500 mL of normal saline flush solution (refer to institution standards or physician prescription regarding use of a heparin flush solution)
Additional equipment to have available depending on patient status includes the following:
PATIENT AND FAMILY EDUCATION
• Assess patient and family understanding of IABP therapy and the reason for its use. Rationale: Clarification or reinforcement of information is an expressed family need during times of stress and anxiety.
• Explain the standard care to the patient and family, including the insertion procedure, IABP sounds, frequency of assessment, alarms, dressings, need for immobility of the affected extremity, expected length of therapy, and parameters for discontinuation of therapy. Rationale: This explanation encourages the patient and family to ask questions and prepares the patient and family for what to expect.
• After catheter removal, instruct the patient to report any warm or wet feeling on the leg and any dizziness or lightheadedness. Rationale: These feelings may be indicative of bleeding at the insertion site.