Modernization of Cardiac Advanced Life Support: Role and Value of Cardiothoracic Anesthesiologist Intensivist in Post–Cardiac Surgery Arrest Resuscitation

Abstract

Cardiac arrest in the postoperative cardiac surgery patient requires a unique set of management skills that deviates from traditional cardiopulmonary resuscitation and Advanced Cardiovascular Life Support (ACLS). Cardiac Advanced Life Support (CALS) was first proposed in 2005 to address these intricacies. The hallmark of CALS is early chest reopening and internal cardiac massage within 5 minutes of the cardiac arrest in patients unresponsive to basic life support. Since the introduction of CALS, the landscape of cardiac surgery has continued to evolve. Cardiac intensivists encounter more patients who undergo cardiac surgical procedures performed via minimally invasive techniques such as lateral thoracotomy or mini sternotomy, in which an initial bedside sternotomy for cardiac massage is not applicable. Given the heterogeneous nature of the patient population in the cardiothoracic intensive care unit, personnel must expeditiously identify the most appropriate rescue strategy. As such, we have proposed a modified CALS approach to (1) adapt to a newer generation of cardiac surgery patients and (2) incorporate advanced resuscitative techniques. These include rescue-focused cardiac ultrasound to aid in the early identification of underlying pathology and guide resuscitation and early institution of extracorporeal cardiopulmonary resuscitation instead of chest reopening. While these therapies are not immediately available in all cardiac surgery centers, we hope this creates a framework to revise guidelines to include these recommendations to improve outcomes and how cardiac anesthesiologist intensivists’ evolving role can aid resuscitation.

Every year, more than 600,000 patients undergo cardiac surgical procedures in the United States, with an incidence of cardiac arrest after cardiac surgery between 0.7% and 2.9%.^1,2 In-hospital cardiac arrest (IHCA) in post–cardiac surgery patients, particularly during the immediate postoperative period, is managed differently than in the general hospital population.^1,3–5 Approximately half of these patients survive to discharge, which is a significantly higher proportion than the overall IHCA patient population. This may be due to the higher probability of reversible etiology of the cardiac arrest. Arrhythmias, namely ventricular fibrillation alone, account for up to 50% of the arrests, with cardiac tamponade and hemorrhagic shock making up the 3 most common etiologies of cardiac arrest after cardiac surgery.^1,3,5–7

This prompted a group of cardiothoracic surgeons and cardiac anesthesiologists to create a specialized protocol for treating cardiac arrest in this patient population, emphasizing rapid serial defibrillation and early emergent chest reopening. In 2006, the group demonstrated improved speed and quality of their resuscitation protocol following implementing the Cardiac Surgery Advanced Life Support (CALS) algorithm.⁸ The protocol has been refined over time. In 2017, the Society of Thoracic Surgeons published its expert consensus statements (Fig 1A).⁹ The protocol has remained largely unchanged in the latest European Resuscitation Council guidelines from 2021 (Fig 1B).⁷ The hallmark of CALS is providing early basic life support with rapid defibrillation and emergency chest reopening within 5 minutes of the cardiac arrest, followed by the initiation of internal cardiac massage. Resuscitative maneuvers in CALS that deviate from traditional ACLS are early serial defibrillation, epicardial or transcutaneous pacing when applicable, and avoidance of 1 mg of epinephrine unless directed by a senior clinician and use of extracorporeal membrane oxygenation (ECMO) (Table 1). Mindful cardiopulmonary resuscitation (CPR) is recommended, but given recent cardiac surgery, early repeat sternotomy should be prioritized. Automated external compression devices were also not recommended due to a lack of evidence at the time, and these devices may hinder efforts to prepare the chest for early repeat sternotomy.

Fig 1.

(A) From the Society of Thoracic Surgeon Cardiac Surgery Advanced Life Support Algorithm Chest reopening protocol. Dunning J, Nandi J, Ariffin S, et al. The Cardiac Surgery Advanced Life Support Course (CALS): Delivering significant improvements in emergency cardiothoracic care. Ann Thorac Surg 2006;81:1767–72. (B) From the Society of Thoracic Surgeon Cardiac Expert Consensce for the Rescuscitation of Patients Who Arrest After Cardiac Surgery. The Society of Thoracic Surgeons Expert Consensus for the Resuscitation of Patients Who Arrest After Cardiac Surgery. Ann Thorac Surg 2017;103:1005–20.¹

Table 1.

Comparison of Different Aspects of Advanced Cardiac Life Support and Cardiac Advanced Life Support

	Advanced Cardiac Life Support	Cardiac Advanced Life Support
Primary focus	Advanced cardiac life support for a variety of situations	Specialized cardiac life support for cardiac surgery patients
Patient population	General population	Patients who have undergone cardiac surgery within the past 10 days
Training requirements	Healthcare professions including physicians, nurses, paramedics	Healthcare professions on cardiac surgery teams including cardiac surgeons, cardiac anesthesiologists and intensivists
Protocols	Standardized algorithms for cardiopulmonary resuscitation, defibrillation, and medications	Tailored protocols considering surgical complications and equipment
Emphasis	Airway management, defibrillations, drug therapy, and postresuscitation chain of survival	Surgical considerations, chest reopening, and specific cardiac interventions including lower epinephrine doses and sequential defibrillations
Use of equipment	Standard ACLS equipment including defibrillations and airway devices	Includes specific surgical tools and techniques including sternotomy sets and ECLS
Common scenarios	Myocardial infarction, arrhythmias, cardiac arrest in various settings	Cardiac tamponade, coronary ischemia, arrhythmias postsurgery
Chest reopening	Not included in protocol	Includes protocols for emergency chest reopening if needed
Special considerations	General cardiac care and emergency response	Specific to complications from cardiac surgery, ie, graft failure
Goals	Return of spontaneous circulation	Stabilization with a focus on next step in reversing etiology of arrest

Rationale for CALS Update

The landscape of cardiac surgery has changed over the Past decade. Historically, most cardiac surgical procedures were done through a complete sternotomy, and many cardiothoracic surgery ICUs did not have intensivist coverage. Today, there are nearly 500 ECMO centers worldwide; minimally invasive or sternal-sparing approaches are increasing in number, and coverage models that include 24/7 cardiac intensivists are increasing in popularity.^10,11 In a 2020 survey of cardiac surgery ICU models, 27.6% of responding units had after-hours coverage by critical care-trained attending staff.¹² While heart transplants and coronary revascularization cases remain the mainstay of cases routinely done by sternotomy,^13–15 an increasing number of surgical valve cases are performed with minimally invasive thoracotomy or percutaneous approaches. Permanent LV assist devices are increasingly implanted via sternal-sparing incisions such as lateral thoracotomy and hemisternotomy, and an increasing number of coronary revascularization procedures are done with a minimally invasive approach.¹⁶ In the 2017 Society of Thoracic Surgeons CALS guidelines, chest reopening can be considered until postoperative day 10 due to possible adhesions in the chest, after which reopening the sternum is deferred to the discretion of a senior clinician. In this new landscape of sternal-sparing techniques, meaningfully opening the chest to allow for internal cardiac massage would require a de novo sternotomy. Additionally, emergent chest reopening in post–cardiac surgery cardiac arrest can be challenging and fraught with potential pitfalls, particularly if there are bypass grafts in place. With the application of the CALS protocol, even with well-trained professionals, the median time to chest reopening has been documented to be longer than 5 minutes.^1,6 Chest opening is no longer recommended once the patient is transferred from the ICU to the general ward. Increasing patient acuity and prolonged preoperative and postoperative ICU stay with multiple operative interventions are now commonplace in most tertiary care centers, making identifying postoperative duration difficult during emergencies. Conversely, with low-risk patients undergoing sternal-sparing cardiac surgical procedures, ICU length of stay has declined, with many patients being transferred to the ward on postoperative day 1.

The cornerstone of resuscitation in an arresting patient remains high-quality CPR and well-organized and performed ACLS. By modifying CALS, we propose introducing rapid TEE imaging and early consideration of mechanical circulatory support with Veno-arterial (VA) ECMO, which helps to stabilize the arresting cardiac surgery patient. Across many institutions, VA ECMO has become an integral aspect of post–cardiac surgery cardiac arrest resuscitation. Since the inclusion of Extracorporeal cardiopulmonary resuscitation (ECPR) into the American Heart Association ACLS guidelines in 2015, its use has expanded worldwide and has since been incorporated into the 2017 Society of Thoracic Surgeons guidelines, the European Resuscitation Council 2021 guidelines, and the American Heart Association ACLS 2023 update.^7,9,17–19 This shift in approach is driven by the changing landscape of cardiac surgery, with minimally invasive or sternal-sparing approaches becoming routine and the increasing availability of ECMO centers and 24/7 cardiac intensivist coverage.^12,20,21 These factors call for reevaluating the CALS protocol and proposing a modified approach to better serve the evolving patient population.

Given the risks and challenges of early repeat sternotomy and the increasing availability of early deployment of mechanical support with VA ECMO at many centers, we propose a modified CALS approach to (1) better adapt to this new landscape of cardiac surgery patients, (2) use rescue echocardiography to diagnose etiology of arrest and guide resuscitation, and (3) incorporate advanced resuscitative techniques, including early VA ECMO implementation, and reserving resuscitative sternotomy and direct cardiac massage for select patients only.

Modification to CALS Protocol

While CALS focuses on early chest opening and internal cardiac massage to improve end-organ perfusion, we suggest starting with external cardiac compressions, rapid defibrillation, and epicardial pacing, incorporating simultaneous use of echocardiography to evaluate the etiology of arrest during CPR and judicious use of early initiation of VA ECMO to provide perfusion to rescue the non-bleeding cardiac surgery patient (Fig 2). There are some caveats to early institution of VA ECMO, including tamponade, bleeding, or aortic dissection, which may mandate early chest reopening to address bleeding. Early preparation and deployment of VA ECMO, including preparation of catheters, cannulas, and bringing the circuit to the field, should be done expeditiously even if VA ECMO is not eventually indicated.

Fig 2.

Proposed modified cardiac surgery advanced life support to incorporate early initiation of VA ECMO instead of chest reopening.

Intensive care practitioners should be familiar with the goals of management during cardiac arrest of providing adequate oxygenated blood to the brain to avoid neurologic injury and attempting to restore coronary perfusion so that a life-sustaining rhythm can be obtained.^22,23 In postoperative cardiac surgical patients, oxygenation will be readily achieved via advanced airway placement and mechanical ventilation. There is conflicting data regarding the superiority of open cardiac massage. It should be acknowledged that in a patient with a recent sternotomy, access to the heart can be relatively rapid. If trained cardiac surgeons are present, the quality of cardiac massage is likely high. Each institution needs to be cognizant of the available resources at night. Less experienced providers are more likely to cause potentially catastrophic complications by reopening the chest to perform effective open cardiac massage. Certain patients, including patients after minimally invasive operations or redo operations, do not lend themselves well to effective cardiac massage as the heart may not be fully exposed. In addition, the time to open the chest is time without perfusion, and any delays in cardiac massage portend a poor prognosis for neurologic function. Therefore, the best cardiac massage option is the one that is available and effective, which is likely closed chest cardiac massage.

The causes of arrest need to be diagnosed to understand who could potentially benefit from emergent repeat sternotomy. Patients with tamponade are the most likely to benefit as repeat sternotomy can be curative for obstructive shock. The chest and mediastinal tube patency should be verified first to rapidly drain any retained effusions. Hemorrhagic shock from bleeding inside the chest cavity is hard to control with bedside exploration but may be an indication of refractory hemorrhage. Although rare, aortic dissections can occur after cardiac surgery, potentially leading to cardiac arrest.^24,25 Other causes of arrest, including hypoxic, pulmonary embolism, and refractory hypotension, are not well served with repeat sternotomy (Table 2).

Table 2.

Common Causes of Cardiac Arrest in the Post–Cardiac Surgery Patient Population

Etiology	Description
Myocardial ischemia	Reduced blood flow to the heart muscle due to blocked or poor flow in coronary arteries
Cardiac tamponade	Accumulation of fluid in the pericardium leading to increased pressure on the heart and restricting filling of cardiac chambers
Arrhythmias	Irregular heartbeats, such as ventricular fibrillation or tachycardia or heart block
Hypovolemia	Decreased blood volume due to excessive bleeding or inadequate fluid repletion
Electrolyte imbalances	Abnormal levels of electrolytes including potassium, calcium, and magnesium
Respiratory failure	Inadequate gas exchange
Low cardiac output syndrome	Inadequate cardiac output due to impaired heart function postsurgery
Sepsis	Severe infection leading to systemic inflammatory response and organ failure

For patients who experience cardiac arrest due to ventricular arrhythmias, the restoration of consistent cardiac output is the highest predictor of a good outcome. Rapid, sequential defibrillation should be attempted as early as possible to restore sinus rhythm. Refractory arrhythmias would only benefit from the ability to directly deliver electrical energy to the heart when external defibrillation is ineffective. In the current era of sequential and vector change defibrillation, it is less clear that there is a real benefit to internal defibrillation.^23,26

With a well-coordinated team, VA ECMO can be established quickly without exposing patients to the risks of chest opening, which include infection, injury to major vessels, as well as failed entry of repeat sternotomy. The likely success of resuscitation with chest reopening is substantially lower in patients who have already been transferred to the wards due to a lack of equipment and suboptimal environmental conditions for surgeons and anesthesiologists. On the other hand, with a well-organized in-hospital mobile team, VA ECMO can be instituted anywhere in the hospital for most post–cardiac surgery patients.¹ Once ECMO support has been initiated, transport to the cardiac catheterization lab or operating room can be safely completed if further definitive interventions are necessary. Furthermore, once VA ECMO is initiated, chest reopening may still be indicated, such as for patients with tamponade or surgical site bleeding. In these cases, tamponade and hemorrhage can be addressed simultaneously (Fig 2). The goal of this modified CALS strategy is to make a definitive decision regarding VA ECMO cannulation within 10 minutes of refractory cardiac arrest and initiate VA ECMO support as soon as possible. While there are data to suggest superior outcomes even with the low-flow time of 60 minutes, a shorter duration of low-flow time is, of course, better.^27,28

Team-Based Approach ECPR for Cardiac Surgical Patients

The critical functions identified for clinical staff are extrapolated from prior CALS guidelines for cardiac arrest management.⁹ It is important to align staff roles with available institutional resources (Figs 4 and 5).

Fig 4.

Key roles in post–cardiac surgery cardiac arrest resuscitation, a sample room diagram and equipment needed.

Fig 5.

An example of an institutional flow diagram for each assigned role in the team-based CALS and ECMO cannulation strategy. It is important to align staff roles with available institutional resources.

1. External cardiac compression: Once the cardiac arrest has been established, one person is allocated to apply chest compressions or to apply an automatic external compression device if available. When immediate defibrillation or pacing is appropriate in clinical scenarios, external cardiac massage is delayed for these maneuvers. In cases where POCUS or TEE identifies the need for surgical exploration, chest compressions need to be paused to allow for sterile preparation for chest reopening at the bedside.

2. Airway and ventilation: The respiratory therapist or anesthesiologist should increase the inspired oxygen to 100%, remove PEEP, and assess the airway and breathing specifically to exclude pneumothorax, hemothorax, or a misplaced endotracheal tube.

3. Defibrillation: This provider should connect the patient to the defibrillator to administer shocks and manage pacing.

4. Team leader: This provider should manage overall cardiac arrest management, ensuring the protocol is followed and each role is assigned. The team leader calls for expert assistance if it is not immediately available. If other staff is available, calling for assistance can be delegated.

5. Medication administration: This nurse oversees the administration of medications appropriate for the patient’s clinical condition at the direction of the team leader.

6. ICU resource or shock nurse or charge nurse: This member coordinates activities outside the room. This includes delegating personnel to bring the ECMO cannulation cart and ECMO circuit to the bedside, informing the perfusionist and cardiac surgeon of arrest and the potential plans for ECPR, and alerting the operating room or cardiac catheterization laboratory of any emergent procedure that may be required. Early notification of the blood bank resources allows for timelier resuscitation with blood products in the event of hemorrhage from ECMO cannulation.

7. Anesthesiologist intensivist: After ensuring a secure airway, deploy TEE or TTE to diagnose the etiology of the arrest. With no obvious reversible causes, the intensivist should gown to prepare for ECMO cannulation. TEE can be left in place and manipulated under the sterile drape to further help the cannulation process.

ECMO Cannulation Team

Those team members previously assigned to sternotomy now fulfill the role of initiating VA ECMO. These members should immediately gown and glove in preparation for ECMO cannulation and should not wait until advanced life support management fails before proceeding. Vascular access should be done in concurrence with advanced life support. Alternatively, the cannulation team can be composed of 3 members in surgical gowns: 2 actively participating in the cannulation and the third acting as support personnel helping to ready the ECMO circuit. Additional team members are not advised as too many people surrounding the patient can make the process of cannulation and initiation of ECMO more difficult. Cardiac anesthesiologist intensivists are often the first responders in initiating ECMO who possess advanced skill sets in ultrasound-guided venous and arterial access. Simulations to ensure providers know where required ancillary equipment is located (echocardiography, ultrasound for line access, central line kits, cannulation material, etc.) as well as require emergency resuscitation medications (heparin, blood, vasopressors, etc.) are crucial.

Successful ECMO cannulation in an emergent situation ideally requires 2 providers: the primary cannulating provider and the assistant. The assistant does not need to be fully trained in the cannulation process, but knowledge of vascular access, wire management, and the steps of ECMO cannulation is critical. Because ECMO cannulation may be a rare event for the assistant, it is important to utilize simulation to prepare providers for this procedure. Depending on the resources available and the reason for arrest, several scenarios should be considered.

1. Closed chest cardiac massage with plans for peripheral VA ECMO as rescue therapy: This is indicated where there is not a perceived value in repeat sternotomy or the risk of reentry is too high, and the plan is to provide ECMO support with further management done once supported on ECMO. Here, only 2 providers are required to be sterile with the bilateral groins prepped. As percutaneous cannulation is the preferred method in emergencies, cannulation here can be performed by cardiac surgeons or other trained providers.

2. Plan for repeat sternotomy with simultaneous peripheral VA ECMO cannulation: This scenario is commonly encountered when the chest is opened and there is no immediate reversible cause identified (tamponade), and the patient remains in extremis or arrest. Here, there are 4 sterile providers needed: 2 for repeat sternotomy and 2 for ECMO cannulation. One of the benefits of this strategy is the ability to continue effective cardiac massage while cannulating the patient. In addition, the surgeons are able to palpate the venous cannula in the field to ensure proper positioning if image guidance is not available.

3. Partial peripheral cannulation: In this scenario, the chest is reopened and the surgeon prepares to place a central aortic cannula for central ECMO. The other trained provider performs peripheral venous cannulation simultaneously to save time and potentially reduce bleeding by avoiding manipulation of the thin right atrium during arrest. While this necessitates some interruption of cardiac massage, there is a benefit to central cannulation with avoidance of north-south syndrome, potentially higher total flows, and the avoidance of limb complications. In arresting patients, the femoral artery may be small, or the patient may have significant peripheral arterial disease that precludes safe peripheral cannulation.

In all these scenarios, good communication is critical. As information is obtained from echocardiography, telemetry review, and laboratory results, the plan should be adjusted to provide the best care.

Other considerations are the need for left ventricular (LV) decompression. A distended LV is unlikely to cardiovert from ventricular fibrillation successfully. Initial maneuvers can be to continue CPR with the aid of the mean arterial pressure support on ECMO and correction of the acid-base status, defibrillation can be attempted. Second-line maneuvers are to place an intraaortic balloon pump, a percutaneous microaxial pump, or a surgical LV vent to decompress the patient and allow for successful rhythm recovery. In addition, an arresting patient may have developed significant pulmonary edema, and close monitoring for north/south syndrome by arterial blood gas analysis and/or cerebral oximetry is strongly recommended. It is prudent for the provider to recognize that in poorly functioning lungs, the aortic root receives hypoxic blood, even if the mixing cloud is in the ascending aorta. Appropriate ventilator adjustments or consideration of venoarteriovenous ECMO should be made to decrease the risk of supplying the brain with hypoxemic blood arising from the aortic root.

Rescue Echocardiography

In the past decade, noninvasive point-of-care ultrasound (POCUS) has been widely adopted to diagnose and manage shock.^29–31 The American Heart Association guidelines in 2020 recommended its use as an adjunct to CPR, provided that it does not interfere with CPR.³² Numerous protocols for incorporating POCUS into ACLS have been proposed over the past 2 decades.^33–36 With ongoing chest compressions, a subxiphoid window is often the best approach to conduct an exam without any interruptions to CPR.³⁶ Transthoracic views, including the parasternal long-axis view, can be used during pulse checks.³⁷ Chest ultrasound can identify large pleural collections or pneumothorax.³¹ POCUS in the setting of cardiac arrest has some limitations. Images obtained during CPR might be non-diagnostic or, worse, lead to misdiagnosis, which can potentially delay definitive therapies or lead to iatrogenic injury.³⁸ Localized clots in the mediastinum, sometimes missed on transthoracic echocardiography, are more common causes of hemodynamic compromise than circumferential effusions in post–cardiac surgery patients.³⁹ Regional wall motion abnormalities may not be readily identified in the setting of ongoing CPR. Using transthoracic ultrasound for cardiac imaging may also be associated with more prolonged interruptions in CPR.^40,41 TEE is preferable if the equipment is readily available, as it can provide continuous imaging during ongoing CPR with a better acoustic window.^42–45

TEE plays a role in the pre-, intra-, and post-cannulation phases of ECPR as a diagnostic modality. It is increasingly used to optimize chest compressions and guide resuscitation while assisting ECPR initiation.^44,46,47 Using anatomical landmarks of the lower half of the sternum during CPR can occasionally lead to compression of the LV outflow tract or aortic root in certain patients and thereby impede cardiac output. The use of TEE during CPR can be used to optimize the location of chest compression to ensure both ventricles are being compressed, improving the success of resuscitation.^46,48 Rescue TEE protocol based on a 5-view sequence has been previously proposed for use during CPR. It includes the mid-esophageal 4-chamber view, the mid-esophageal aortic valve long axis view, the mid-esophageal bicaval view, the transgastric short-axis view, and the transgastric descending aorta short-axis view (Fig 3).^44,46,47 A more extensive TEE protocol, including transesophageal lung and transesophageal abdominal ultrasound, can be undertaken if the etiology of the arrest has not yet been identified with limited rescue protocol.⁴⁶ TEE can aid in identifying fine ventricular fibrillation, which can be mistaken for asystole on cardiac monitors, leading to missed opportunities for defibrillation. TEE may also identify pseudo-pulseless electrical activity, where aortic valve opening is present in a very low cardiac output state, leading to an undetectable pulse that may respond to vasopressors.^35,49 Aortic valve velocity time-integral can be used as a surrogate for stroke volume and further help determine the degree of decreased cardiac output.⁵⁰ The challenges of TEE examination during CPR must be recognized. Regional wall motion abnormalities and ventricular function on echo are challenging to interpret during CPR. In the setting of a newly placed prosthetic valve, valvular function assessment can be challenging in the setting of reduced cardiac output during CPR. Iatrogenic injury to oropharyngeal structures and the esophagus from the TEE probe placement during CPR is certainly possible, but the incidence is unknown. As such, TEE during cardiac arrest should only be performed by those with considerable experience in performing and interpreting routine TEE examinations.

Fig 3.

Five-view sequence rescue TEE. (A) ME 4-chamber view with visualization of all 4 chambers. (B) ME LAX view with visualization of the left ventricle and mitral and aortic valve. (C) ME bicaval view with hyperechoic wire approaching from the superior vena cava. (D) TG Midpapillary SAX view with visualization of contractility and left ventricular filling. (E) Descending aortic SAX view with visualization of a wire in the descending thoracic aorta at the 3 o’clock position. ME-,midesophageal; LAX, long axis view; SAX, short axis view.

TEE can also verify venous and arterial access for ECPR in the challenging environment of ongoing CPR. The bicaval view will ensure that the venous access obtained in the femoral vein extends to the right atrium and that the venous cannula is placed correctly. Likewise, confirmation of the wire in the descending aorta will confirm that the wire presumed to be placed in the femoral artery is in the femoral artery. Last, iatrogenic procedural complications, including wire injury resulting in dissection or tamponade, can be identified. TEE is also used to ensure that preexisting tamponade was not caused by ECMO cannulation or if new effusions are found that they may be a result of attempted VA ECMO cannulation.

After ECMO cannulation, TEE can be used to assess and monitor changes in cardiac function. A complete transesophageal echocardiogram should be performed following ECMO initiation if not used during resuscitation and cannulation. Another common iatrogenic injury during ECMO cannulation includes retroperitoneal hemorrhage. While TEE cannot directly visualize this complication, hypovolemic volume status, inability to maintain constant ECMO flows, and dropping hemoglobin may indicate this complication. Intraperitoneal fluid visualized by TEE may also indicate a wire injury with ongoing bleeding. Wall motion abnormalities, thrombus, and valvular dysfunction may be discovered. Evaluation of LV size and systolic function can help identify patients at risk for LV distention and may prompt earlier consideration of venting strategies. If no aortic valve opening is demonstrated, then LV venting with an intraaortic balloon pump or Impella device may be necessary to prevent LV and root thrombus. Patients immediately after ECMO cannulation can be intravascularly hypovolemic and require aggressive fluid resuscitation to adequately allow assessment of the LV ejection. Valvular abnormalities such as acute rupture MR or paravalvular leaks may be discovered.

Immediate Post-ECPR Considerations

In the first 24 hours of ECMO, patients require a tremendous amount of care and resuscitation. Before transporting the patient to a different location, the team must verify adequate ECMO flows and ensure no iatrogenic injuries with ECMO cannulation. ECMO cannulas need to be secured appropriately to minimize the risk of bleeding and catastrophic dislodgement. In patients with small or diseased vasculature or those on high vasopressor-inotropic support, distal limb ischemia in the ipsilateral limb of the arterial cannula has a significant impact on the patient’s overall mortality.^51,52 A reperfusion catheter can be performed at the bedside, or if a coronary angiography is planned, a reperfusion catheter can be placed in the cardiac catheterization laboratory. Alternatively, monitoring of limb perfusion with vascular Doppler and tissue oxygen saturation with near-infrared spectroscopy (NIRS) can indicate the need for a distal perfusion catheter. With retrograde flow from the outflow cannula up the aorta effectively increasing LV afterload against a weak or non-pulsatile heart, it is crucial to determine if LV decompression is needed.

Placement of a pulmonary artery catheter after the initiation of VA ECMO can be helpful to further guide management, assess adequacy of ECMO support, monitor for changes in right and left heart function, and guide the need for LV unloading by measurement of pulmonary capillary wedge pressure.^53–55 While there lacks evidence for routine use of a pulmonary artery catheter in all patients, the authors do recommend its use if aforementioned parameters are helpful in patient management and weaning. Arterial pulsatility and aortic valve opening should be maintained while on ECMO if possible. The absence of pulsatility increases the risk of LV distention as well as LV and aortic root thrombus. There lacks evidence for improved outcome with increased pulse pressure. In the authors experience, pulsatility of 10 to 15 mmHg can be achieved by adjusting ECMO flows, titrating inotropic medications, decreasing afterload, and if unable to be achieved, consideration of LV venting.

Simulation-Based Training for CALS and ECPR

Given the varied backgrounds and levels of training, extensive team-based simulation training ensures the achievement of similar skill sets. Cannulation team members should be trained in all aspects of the equipment, including supplies needed for ECMO cannulation, ECMO initiation, and equipment troubleshooting. Due to the limited number of ECMO cannulations performed in the post–cardiac surgery environment, simulation is used for initial training and continued quality assessment. This is important to simulate all periods of the day when fewer ICU staff are available or when attending cardiac surgeons have competing operative cases during daytime hours and cannot assist in cannulation for ECPR.

Our preferred cannulation site is the left common femoral artery and the right common femoral vein as the inferior vena cava lies along the right anterolateral aspect of the vertebral column. Contralateral arterial cannulation is preferred to minimize inadvertent cannulation in the same vessel or possible arteriovenous fistulas. In emergent situations, this is the most accessible location for the cannulation team while external compression occurs. In surgical patients with a prior femoral cutdown for femoral access during the initial surgical case, the team is trained to reopen the femoral cutdown to access the femoral vessel as ultrasound imaging over the groin closure can be difficult especially in cases of staples. Ultrasound-guided percutaneous access is the standard in all other patients, and thus, ultrasound guidance and localization are essential components of hands-on training. The location of percutaneous vascular access should be done below the inguinal ligament and in the common femoral artery before the bifurcation into the superficial femoral artery and profunda femoris. The first responders of the team are expected to gain initial vascular access by placing sheaths into the artery and vein or directly inserting the wire if the ECMO cannulators are not yet at the bedside. Vascular access distal to the bifurcation of the common femoral artery (superficial femoral artery access) can lead to limb-threatening complications or arterial rupture due to the inability to accommodate the cannula because of the small vessel caliber. The wire should also be confirmed in the aorta to prevent inadvertent passage into the deep circumflex iliac artery. Cannulation of the artery is contraindicated if dissection exists within the artery. Adequate training and experience in identifying crucial landmarks are important components of proper cannulation technique. While the femoral vessels are the most straightforward cannulation sites in emergencies, they are not the only access sites. Cannulation of the axillary or subclavian vessels requires even more training and experience. High-fidelity simulation is a resource-intensive endeavor. For centers without the necessary staff or tools, well-organized simulation courses are conducted by international ECMO organizations and larger academic centers.

Clinical training to become a credentialed cannulator includes observation in an assistant role and acting as the primary cannulator role under supervision. Each hospital team can set the minimum number of cannulations necessary before becoming independent cannulators. Currently, there is no formal training pathway for ECMO cannulation. Ongoing quality assurance programs should include regularly scheduled case review conferences with continued feedback on ECMO initiation and management. Accurate record-keeping ensures patient safety, facilitates effective communication among healthcare providers, and maintains legal and regulatory compliance. Detailed and precise documentation of patient assessments, treatments, and interventions is essential for tracking patient and program progress, identifying trends, and making informed programmatic decisions.

Moreover, meticulous record-keeping is crucial for continuity of care, enabling seamless transitions between healthcare settings and providers if necessary. In addition to supporting clinical care, accurate documentation is vital for billing and reimbursement purposes, ensuring appropriate allocation of resources and financial integrity within healthcare systems. A thorough and precise record-keeping commitment is fundamental to delivering high-quality, patient-centered care and fostering trust between patients, providers, and healthcare institutions.

Role of the Cardiac Anesthesiologist and Anesthesiology Intensivist

The cardiac anesthesiologists’ roles have evolved beyond the traditional clinical boundaries of the operating room. Though only 5% of the nearly 30,000 intensivists in the United States are anesthesiology intensivists, with approximately 70% of anesthesiology intensivists practicing in cardiothoracic ICUs.⁵⁶ Cardiac anesthesiologists and intensivists now participate in ICU coverage, acute shock teams, ECMO teams, and transplant and MCS committees and have been integral in creating echocardiography protocols and guidelines during resuscitation.^{12,47,57–60} A 2020 survey of cardiac surgery ICU models in the United States found that 26% of cardiothoracic surgery ICU coverage is provided by anesthesiology-trained intensivists, the second most represented specialty.¹² Dual fellowship-trained cardiac anesthesiologist intensivists’ unique technical skillset includes performing point-of-care ultrasound and advanced TEE guiding ECMO cannulation and any further interventions. Cardiac anesthesia intensivists must continue to play a vital role in expanding ECPR teams and continually modifying simulation-based team training to adapt to this changing landscape. This evolution underscores anesthesiologists’ adaptability to embrace multifaceted roles within the hospital system, reinforcing their integral position in the collaborative and comprehensive care of patients with acute complex cardiac conditions. As intensivist staffing models are shifting to 24/7 in-house coverage, intensivists are now the initial clinicians capable of initiating VA ECMO at the bedside.

Institutional Variability

Institutional variabilities in staffing and equipment availability significantly influence the delivery of critical care across healthcare facilities (Fig 6). Hospitals with robust staffing resources, including a higher ratio of trained intensivists, specialized nurses, and ancillary support staff, often provide more comprehensive and timely care to critically ill patients. Consequently, addressing disparities in staffing levels and equipment availability is paramount for ensuring equitable access to high-quality critical care across different healthcare settings. Efforts to enhance resources, optimize staffing models, and facilitate collaboration between institutions can help bridge these gaps and improve the overall delivery of critical care services. Notable differences among this multi-institutional collaboration included using precannulation sheaths into the appropriate vessels before cannulation, mainly due to the difference in nighttime staffing to allow for initial vascular access to be done before cannulation as well as the immediate availability of TEE in the ICU, which incurs a significant cost but also requires a process to allow for TEE probe storage, cleaning, and maintenance. Institutions that do not frequently use TEE in the intensive care unit may choose to store the ultrasound and probes along with other ultrasound machines and probes, which often is the operating rooms. Processes should be developed to allow rapid utilization of these resources when needed. Adapters are available for certain TEE probes to allow their use with smaller ultrasound systems often found in the ICUs. Unit-based quality initiatives will allow resuscitation programs fitting to staffing, equipment, and institutional culture.

Fig 6.

(A) The University of Rochester and Vanderbilt University ECMO Carts. Each drawer contains supplies needed and is stocked in sequential order. The top of the cart can then be converted into a sterile work area. Several arterial and venous cannulas are located on the side. LUCAS and EZ-IO kits are also part of the chart and are used frequently in the resuscitation process. (B) The University of Pennsylvania ECMO Cart. From Olia S, Francis C, Terranova CRNP, et al. A prescriptively designed, human factors focused, emergency ECMO cart for cannulation or circuit exchange. ASAIO J 2023;69(Suppl 3):45. 10.1097/01.mat.0000990840.08372.11

Conclusion

Early chest reopening after arrest has been a hallmark of resuscitation of cardiac surgical patients after cardiac arrest for more than a decade. With the advent of sternal-sparing cardiac surgical procedures, expanding expertise in ECPR worldwide, and broader adoption of POCUS for routine clinical decision-making among cardiac intensivists, there is an opportunity to modify CALS to embrace this new landscape. One such protocol is proposed here. Further research is needed to establish the cohort of patients who would most benefit from repeat sternotomy or de novo sternotomy in the event of cardiac arrest in the postoperative period, as opposed to the early utilization of ECPR for refractory arrest. With expertise in echocardiography, resuscitation, and ultrasound-guided access, cardiac critical care anesthesiologists are uniquely positioned as integral members of the cardiac surgical teams in rescuing these patients. By expanding mobile ECMO/ECPR cannulation teams for IHCA and advocating for simulation-based team training, cardiac critical care anesthesiologists can improve outcomes and reduce healthcare-associated disparities in patients who sustain arrest after cardiac surgery among various centers worldwide.