Medical Director Message May 2024

Dr. Jordan Singer

Dr. Singer is an EMS Medical Director for numerous departments under many UH Hospitals

May 6, 2024

Good morning, 


This month we will be focusing on cardiac devices since many patients are discharged with implanted devices that treat a specific abnormality with their hearts. One of these devices is a left ventricular assist device (LVAD), which is used to treat severe left-sided heart failure that is refractory to other treatments.  


What is an LVAD?


An LVAD is a mechanical pump that is implanted inside a patient and used in the treatment of severe heart failure. The pump sucks blood out of the left ventricle and pumps it into the aorta to improve the native heart’s ability to generate blood flow to the rest of the body. The manufacturer and generation of the pump varies. In addition, current generation LVADs produce non-pulsatile flow, meaning that for the majority of LVAD patients, you will not be able to feel a pulse despite having a normal cardiac output. A picture of the Abbot HeartMate 3 from their website is included below as a reference:  



How are LVADs used?


There are three scenarios in which LVADs are commonly used. 



Potential LVAD patient risks of complications: 


 

Understanding how LVADs work and why they are placed helps EMS responders evaluate and treat these patients when they are having a medical emergency.  


Be safe and keep up the awesome work! 




Jordan Singer, MD

May 13, 2024

Good morning, 


As we continue focusing on cardiac devices, we recognize that many patients are discharged home with implanted devices that treat a specific abnormality with their hearts. One of these devices is a left ventricular assist device (LVAD), which is used to treat severe left-sided heart failure that is refractory to other treatments. Last week, we had a quick overview of the device to understand how it works. This week, we will discuss how to treat the critically ill LVAD patient. Management is broken up into three phases: preparation, patient assessment, and treatment.


Preparation


While LVADs are becoming more common, they are still rare. It is important for EMS agencies to be aware of who in their communities have LVADs. It is common practice for patients and hospitals to reach out to local EMS when a patient is discharged home with an LVAD to allow EMS providers to prepare for complicated medical emergencies that may occur in these patients. EMS agencies should request a copy of the specific troubleshooting guide for the specific device that the patient has. Crews can periodically review the guide to keep the information fresh. It is similar to how we should review protocols that we do not use as often. When we get dispatched to the patient, we can even bring the troubleshooting guide to review while en route and reference if the patient does not have the guide available on scene.


Assessment


The first step in assessing the patient is to determine stability or if they are critically ill. If the patient is stable, then we should assess the device, assess for perfusion, and then follow the appropriate protocol based on the issue at hand. 


Assessing the device: Auscultate the heart and listen for the hum of the LVAD. If the hum is not present, this should raise concerns about the device having had a critical error. We also should look at the controller and ensure no errors are triggering, and that the device has enough battery life.  


Assessing perfusion: LVAD patients often do NOT have a pulse since the LVAD provides non-pulsatile flow and the patient’s native heart is too weak to make a pulse. It prevents us from obtaining manual blood pressures (BPs) and from using automatic cuffs. It also prevents us from obtaining a heart rate. We need to use alternative means of assessing perfusion such as mental status, capillary refill, color and temp of extremities, and ETCO2.  


Routine assessment per protocol: Last week, we discussed specific complications that LVAD patients are at risk of, but we should also remember that these patients can have more routine problems such as urinary tract infections, pneumonia, and trauma. 


Treatment


The next step would be to treat any issues that arise during your assessment. 



Be safe and keep up the awesome work! 




Jordan Singer, MD

May 20, 2024

Good morning, 


This month we will focus on cardiac devices. Many patients are discharged home with implanted devices that treat a specific abnormality with their hearts. Over the last two weeks we reviewed left ventricular assist devices (LVADs). This week we will review pacemakers which are used to treat chronic bradyarrhythmias.  


What is the purpose of pacemakers?


This device automatically treats patients who develop bradyarrhythmias. These are commonly placed in patients who go in and out of high-grade AV block or complete heart block. The shocks delivered to the heart are so minor that they cannot be felt (pacers do not go off). When a patient’s intrinsic heart rate drops below a certain programmed cut-off (which is often 60 bpm), the pacemaker turns on and maintains a ventricular rate at that cut-off. When the patient’s intrinsic heart rate is greater than the cut-off, the pacemaker does nothing.  


What types of problems can patients have related to their pacemaker?


If the patient is markedly bradycardic, assume that the pacer has failed since the job of the pacemaker is to prevent marked bradycardia. In this situation, EMS should treat the bradycardia as if the patient did not have a pacemaker. If the patient is stable, then use supportive care. If the patient is unstable, we would use medications and transcutaneous pacing. If we decide to pace the patient, we should be careful not to place the pads directly over the device. Of note, hyperkalemia can often cause bradyarrhythmias that do not respond to pacing. EMS should consider this potential cause of a pacer failing, and if the suspicion is high enough, treat it with calcium in addition to other treatments the protocol mentions for hyperkalemia.  


Pacemakers are implanted devices used to treat chronic or recurrent bradyarrhythmias. Malfunctions are not common, but when they occur, EMS providers need to be ready to treat them. The good news is that treating bradyarrhythmias in the setting of pacemaker malfunction is identical to their treatment in patients who do not have pacers. 


Be safe and keep up the awesome work! 




Jordan Singer, MD

May 27, 2024

Good morning, 


This month we continue focusing on cardiac devices. Many patients are discharged home with implanted devices that treat a specific abnormality within their hearts. Last week, we discussed pacemakers, and prior to that, we reviewed left ventricular assist devices (LVADs). This week, we will review automatic implantable cardioverter-defibrillators (AICD), which are used to treat recurrent ventricular tachyarrhythmias such as ventricular tachycardia (VT) and ventricular fibrillation (VF).  


What is the purpose of AICDs? 


This device automatically treats patients who develop VT/VF. They are implanted in patients who are at high risk for developing these rhythms, such as patients with severe congestive heart failure and patients who experience sudden cardiac arrest for VT/VF for unclear reasons. The device will analyze the patient’s rhythm in real time and deliver the appropriate electrical therapy based on how the AICD was programmed and the patient’s rhythm. 


What types of problems can patients have related to their AICD?


There are three possible scenarios: 


AICDs are common devices that can treat potentially fatal cardiac arrhythmias. They often do not cause issues for patients, but EMS providers need to understand them so that we can effectively treat these issues when they arise. 


Be safe and keep up the awesome work! 




Jordan Singer, MD