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Challenging Case: Management of Intracranial Hemorrhage in a Patient with a Left Ventricular Assist Device (LVAD)

Amir Mohajerani, MD

Adele Budiansky, MD, FRCPC

Amir Mohajerani, MD
Neuroanesthesiology Fellow,
Cleveland Clinic Foundation
Cleveland OH, USA

Adele Budiansky, MD, FRCPC
Staff, Department of Anesthesiology and Pain Medicine,
The Ottawa Hospital
Ottawa, Canada

Introduction
Left ventricular assist devices (LVADs) are increasingly used for the management of severe heart failure both as a bridge to heart transplantation as well as a means of extending and improving the quality of life of heart failure patients who are not candidates for transplantation ("destination therapy"). The basic purpose of the LVAD is to offload the failing left ventricle, thus decreasing LV work, reducing pulmonary pressures, and improving end-organ perfusion [1]. Further details of various LVAD devices, their mechanism of action, and their complications can be found elsewhere [2].

As the number of patients with LVADs increases, anesthesiologists can encounter these patients for noncardiac surgeries. We are highlighting neurosurgical management of intracranial hemorrhage (ICH) in such patients. Indeed, multiple studies have demonstrated an increased risk of ICH in patients with LVADs compared to the general population or patients with advanced heart failure without LVADs. A recent systematic review found the rate of ICH in LVAD patients to be around 10% [3]. There are multiple risk factors for ICH in this population. Most importantly, patients with LVADs require lifelong anticoagulation to prevent thrombosis within the pump mechanism.

It has also been suggested that the non-pulsatile flow generated by many of the LVAD devices can lead to cerebral microbleeds [4] and inherent coagulopathy due to shearing of von-Willebrand factor as blood flows through the device [5]. In general, LVAD patients who require neurosurgical intervention for ICH tend to have poorer outcomes and overall survival with intraparenchymal hemorrhage as compared to patients with acute subdural hematoma [3].

This report discusses the anesthetic considerations and management of a 63-year-old patient with an LVAD who presents to the operating room with an ICH.

Case Description
A 63-year-old man was booked for an emergency craniotomy for an acute subdural hematoma (SDH). He tripped in the bathroom at home and hit his head on the edge of the sink. He now presents with a GCS of 13 and a CT scan showing a large right SDH with midline shift. His medical history includes non-ischemic cardiomyopathy, for which an LVAD was implanted three years back, chronic kidney disease, and an implanted defibrillator (ICD). He is on warfarin, and his INR in the emergency department was 3.4. His recent echocardiogram showed a dilated left ventricle with an ejection fraction of 20% and mildly reduced right ventricular function.

Prothrombin complex concentrate was administered to the patient en route to the OR. A perfusion technician was present in the OR to monitor the LVAD, while a device technician deactivated the ICD as external defibrillation pads were placed on the patient. The neurosurgeons were notified of the need to use cautery in short bursts to minimize electromagnetic interference.

A brachial arterial line was placed under ultrasound guidance before induction. A 250 ml bolus of crystalloid was administered prior to induction. Induction was completed with fentanyl, etomidate, and rocuronium, and the patient was intubated with direct laryngoscopy. A norepinephrine infusion was prepared and started peri-induction to maintain a MAP of 80 mmHg. Ventilation parameters were adjusted to achieve normocarbia. Following discussion with the surgical team, we chose to forgo administration of a hypertonic solution. The patient required one unit of packed red blood cells.

The perfusion technician provided updates on the LVAD’s function throughout the procedure. There were no reported issues, such as “suction events,” and the device flow rate remained within normal limits. The patient’s defibrillator was reactivated at the end of the procedure.

The procedure was completed uneventfully, and the patient was transferred to the intensive care unit for further ventilation and management.

Discussion
To safely manage a patient with an LVAD presenting for neurosurgical procedures, the following questions should be considered:

1. What are the main anesthesia considerations for managing a patient with an LVAD?
2. How should these patients be monitored intraoperatively?
3. What are the perioperative hemodynamic goals for patients with an LVAD?
4. How should anticoagulants be managed perioperatively in LVAD patients?
5. What post-operative complications can be anticipated in this patient?
6. Are there any anesthetic goals for ICH that conflict with those of LVAD management?

Patients with LVADs should ideally be managed at an institution more familiar with LVAD therapy and include a team comprised of an LVAD-knowledgeable perfusionist or operator, cardiologists, and anesthesiologists. A team member who can monitor the LVAD, reporting on the patient's perfusion status, and modifying device settings (such as the flow rate) on the LVAD console should be present intraoperatively to assist the anesthesiologist [6]. The LVAD should be connected to a continuous power supply in the operating room not to use its battery life.

A five-lead ECG should be monitored for arrhythmias, as these are poorly tolerated. Because the LVAD generates a non-pulsatile or minimally pulsatile systemic blood flow, only the mean arterial pressure (MAP) is reliably measured. Oscillometric noninvasive blood pressure measurement is often inaccurate and is inferior to Doppler-based measurements. Any prolonged surgery or one with expected hemodynamic fluctuations should prompt an arterial line insertion using ultrasound due to the lack of palpable pulses. Due to the dampened or absence of pulsatility, monitoring oxygen saturations with standard pulse oximetry may be problematic; therefore, serial arterial blood gas or trending cerebral oximeter saturation is a surrogate. A transesophageal echo may be helpful for the assessment of volume status.

The hemodynamic goals in patients with an LVAD include preservation of preload to the pump, maintenance of right ventricular (RV) function (as device filling is dependent on forward flow from the RV), and maintenance of adequate afterload. Because these patients are very much preload-dependent for adequate device functioning, hypovolemia should be carefully avoided, and RV function preserved. Hypovolemia can result in “suction events,” whereby the LVAD inflow cannula pulls in a wall of the underfilled LV towards it, causing device obstruction [5, 7].

While systemic vascular resistance should be controlled to keep the patient near their baseline MAP (typically 70-80 mmHg) to maintain adequate perfusion, hypertension (MAP >90 mmHg for LVADS) [6, 8] or sudden increases in the afterload will impair forward LVAD flow and increase risk of device thrombosis.

LVAD patients are on life-long warfarin therapy, while some may also take antiplatelet agents to prevent devastating thrombosis within the device. In the case of an elective procedure, warfarin can be discontinued 2-5 days before the operation and the patient placed on a bridging heparin infusion. In an emergency setting, the benefits of rapid anticoagulation reversal must be balanced against in-device thrombosis risk. A study of patients with LVADs presenting with acute ICH found that reversal of warfarin with prothrombin complex concentrate (PCC) did not result in increased thromboembolic events compared to administration of fresh frozen plasma (FFP) [9]. Patients waiting for transplant should be considered for irradiated blood products.

As in the scenario described above, it is not uncommon for patients with LVADs to have an implanted pacemaker or defibrillator. Arrhythmias are poorly tolerated in these patients because they impair device filling. Of note, chest compressions are often avoided in patients with LVADs during ACLS because of the risk of device disruption. Device-specific recommendations should be reviewed.

Anticipated Post-Operative Complications
Decision making around the timing of anticoagulation resumption post-operatively in patients with LVADs is challenging. Once again, the risk of further hemorrhage must be balanced against the risk of thromboembolic events. In general, newer generation devices carry a lower thromboembolic risk than first-generation LVADs.

Neuroanesthesia Considerations in the LVAD Patient
The use and choice of hypertonic solutions for raised intracranial pressure (ICP) should be balanced with hypovolemia risk in these preload-dependent patients. Similarly, while it may be desirable to increase the MAP to maintain adequate cerebral perfusion pressure in a patient with high ICP, this must be weighed against the effects of excess afterload on LVAD function. As is the case for a patient with increased ICP, it is imperative to prevent sudden sympathetic surges in LVAD patients, which can occur during direct laryngoscopy or pinning of the head.

Conclusion
The complexity of LVAD systems coupled with the physiologic derangements of chronic heart failure presents unique challenges to anesthesia in noncardiac surgeries.
Maintaining hemodynamic and ventilator goals is crucial during anesthesia and need anesthesiologist knowledge of LVAD management. The need for chronic anticoagulation and antiplatelet therapy affects perioperative management.

The anesthetic technique for noncardiac surgery in LVAD patients is not clear. Thus, perioperative management of LVAD patients should be based on shared decision-making among the patient, anesthesiologist, LVAD team, and surgeon to ensure better outcomes.

References:

1. Slaughter MS, Rogers JG, Milano CA, et al. Advanced heart failure treated with continuous-flow left ventricular assist device. N Engl J Med. 2009;361:2241-51.
2. Long B, Robertson J, Koyfman A, et al. Left ventricular assist devices and their complications: A review for emergency clinicians. Am J Emerg Med. 2019;37:1562-1570.
3. Carroll AH, Ramirez MP, Dowlati E, et al. Management of Intracranial Hemorrhage in Patients with a Left Ventricular Assist Device: A Systematic Review and Meta-Analysis. J Stroke Cerebrovasc Dis. 2020;30:105501.
4. Lai GY, Devlin PJ, Kesavabhotla K, et al. management and outcome of intracranial hemorrhage in patients with left ventricular assist devices. J Neurosurg. 2019;1-7.
5. Roberts SM, Hovord DG, Kodavatiganti R, et al. Ventricular assist devices and noncardiac surgery. BMC Anesthesiol. 2015;15:185.
6. Dalia AA, Cronin B, Stone ME, et al. Anesthetic Management of Patients With Continuous-Flow Left Ventricular Assist Devices Undergoing Noncardiac Surgery: An Update for Anesthesiologists. J Cardiothorac Vasc Anesth. 2018;32:1001-1012.
7. Sen A, Larson JS, Kashani KB, et al. Mechanical circulatory assist devices: a primer for critical care and emergency physicians. Crit Care. 2016;20:153.
8. Bennett MKAdatya S. Blood pressure management in mechanical circulatory support. J Thorac Dis. 2015;7:2125-8.
9. Wong JK, Chen PC, Falvey J, et al. Anticoagulation Reversal Strategies for Left Ventricular Assist Device Patients Presenting with Acute Intracranial Hemorrhage. Asaio j. 2016;62:552-7.