What to do if a patient with an Intra-Aortic Balloon Pump (IABP) loses their pulse?

Loss of Palpable Pulse in IABP Patients

When a patient with an IABP loses their palpable pulse, this is often an expected physiological finding rather than a sign of cardiac arrest, and you must immediately obtain invasive arterial pressure monitoring via an arterial line to accurately assess their hemodynamic status. 1

Immediate Assessment Steps

First: Determine if This is True Cardiac Arrest or IABP-Related Pulse Loss

• Check for invasive arterial pressure monitoring immediately - the IABP's counterpulsation mechanism can make peripheral pulses difficult or impossible to palpate even when the patient has adequate perfusion and mean arterial pressure. 1, 2

• Assess the patient's level of consciousness - if the patient is awake, alert, and responsive, this confirms adequate cerebral perfusion despite absent peripheral pulses. 2

• Monitor for signs of adequate tissue perfusion including maintained urine output, stable or improving lactate levels, and preserved mental status. 2

• Verify continuous ECG monitoring is in place to distinguish between organized cardiac rhythm with mechanical dysfunction versus true cardiac arrest. 3, 2

Critical Distinction: The IABP Effect on Pulse Assessment

The IABP creates counterpulsation that fundamentally alters the arterial waveform, making traditional pulse palpation unreliable or impossible. This is a known limitation of IABP therapy, not necessarily a clinical emergency. 1, 2

If Invasive Monitoring Shows Adequate Blood Pressure

When Mean Arterial Pressure is Present (>65-70 mmHg)

• Continue IABP support and maintain mean arterial pressure above 90 mmHg or no more than 30 mmHg below baseline to ensure adequate coronary perfusion. 3, 2

• Place an arterial line in the right radial artery (preferred site to avoid IABP interference) for continuous invasive blood pressure monitoring - this is the standard of care for all IABP patients. 2

• Document IABP settings including timing, ratio, and augmentation pressures at regular hourly intervals. 2

• Monitor hemodynamic parameters continuously - the absence of a palpable pulse is acceptable as long as invasive monitoring confirms adequate perfusion pressure. 2

If True Cardiac Arrest is Confirmed

Immediate CPR Management with IABP in Place

• Initiate high-quality CPR immediately with proper depth (at least 5 cm), rate (100-120 compressions/min), and minimal interruptions - this takes priority over IABP adjustments. 3

• Maintain IABP operation during CPR as it may augment coronary perfusion pressure and improve outcomes, though you should focus primarily on delivering uninterrupted chest compressions. 3, 4

• Target coronary perfusion pressure >20 mmHg or arterial diastolic pressure >25 mmHg during CPR when invasive monitoring is available. 3

• Use end-tidal CO2 monitoring as a surrogate marker of CPR quality and cardiac output. 3

• Minimize pre-shock and post-shock pauses in chest compressions as these significantly impact survival. 3

IABP-Specific Considerations During Resuscitation

• Keep the IABP running at maximum augmentation (1:1 ratio) during cardiac arrest to maximize diastolic pressure augmentation and coronary blood flow. 3

• Consider IABP as reasonable rescue treatment when initial therapy is failing for cardiac arrest that occurs during PCI (Class IIb recommendation). 3

• Evaluate for more advanced mechanical circulatory support early (ECPR, ventricular assist devices) if the patient remains in refractory cardiac arrest despite IABP and optimal CPR. 1, 3

Post-ROSC Management

After Return of Spontaneous Circulation

• Continue IABP support to reduce afterload and improve coronary perfusion in patients with post-cardiac arrest myocardial dysfunction. 3

• Maintain mean arterial pressure above 90 mmHg or no more than 30 mmHg below baseline to ensure adequate coronary perfusion. 3

• Implement serial echocardiography to evaluate ventricular function and response to IABP support. 2

• Monitor for left ventricular unloading as the IABP can prevent distension, ventricular stasis, and myocardial ischemia, potentially improving survival. 3

Common Pitfall to Avoid

The most critical error is assuming absent peripheral pulses in an IABP patient equals cardiac arrest. The IABP's counterpulsation mechanism routinely makes peripheral pulses non-palpable even with adequate perfusion. Always verify hemodynamic status with invasive arterial monitoring before initiating resuscitation. 1, 2 Unnecessary CPR in a hemodynamically stable patient can cause significant harm including rib fractures, pneumothorax, and interruption of effective IABP therapy. 3