Anesthesia for emergency cardiac surgery

INTRODUCTION — 

Selected patients require emergency cardiac surgery, and some are unstable upon presentation to the cardiac operating room. Examples include mediastinal re-exploration for early postoperative bleeding, acute ascending (type A) aortic dissection, cardiogenic shock or mechanical complications after acute myocardial infarction (eg, acute mitral regurgitation from papillary muscle rupture, ventricular septal defect, left ventricular free wall rupture), ongoing ischemia after unsuccessful or complicated percutaneous coronary intervention, critical aortic stenosis with coexisting unstable coronary artery disease, acute severe aortic regurgitation with pulmonary edema, or presence of large mobile vegetations due to endocarditis [1]. Patients requiring emergency surgery have a high risk of morbidity and mortality [2-6], particularly if they experience preincision cardiac arrest [7].

PREOPERATIVE CONSIDERATIONS — 

The anesthesiologist must perform a rapid preoperative evaluation and preparation for surgery, but may have limited time to question the patient directly and/or review the medical record.

Preoperative assessment — Important issues include:

●Assessing the cardiac pathophysiology and understanding the emergency nature of the proposed procedure, as well as any preoperative interventions that may affect management (eg, attempted thrombolysis). Review the patient's chart, as time allows.

●Checking recent laboratory values and ordering any laboratory tests that may be missing. (See "Evaluation of cardiac risk prior to noncardiac surgery".)

●Checking the availability of blood products. It is prudent to have a sufficient number of red blood cell (RBC) units typed and crossmatched to address any existing anemia and anticipated surgical blood loss (see "Overview of preoperative evaluation and management for cardiac surgery in adults", section on 'Pretransfusion testing'). If massive transfusion is a possibility, preoperative communication with the cardiac surgeon regarding estimates of potential blood loss and subsequent communication with the blood bank are essential.

In some emergency situations (eg, rapid bleeding due to aortic dissection) (see 'Acute aortic dissection' below), there might not be time to perform full blood-type compatibility testing. Decisions regarding transfusion in such settings depend on assessment of the risks and benefits of immediate transfusion versus full blood compatibility testing. Importantly, "emergency release" blood, typically group O, is always available for immediate lifesaving transfusion. (See "Pretransfusion testing for red blood cell transfusion", section on 'Emergency release blood for life-threatening anemia or bleeding'.)

●Speaking briefly to the patient, family members, and/or care team members (eg, cardiologist, cardiac surgeon, intensivist, intensive care nurse) to determine and confirm:

•Allergies

•Fasting status

•Relevant past medical and surgical history

•Problems with prior anesthetics

•Recently administered medications (eg, chronically administered antiplatelet and/or anticoagulant agents) - (See 'Emergency reversal of medications affecting hemostasis' below.)

•Noting the presence of an implantable cardioverter-defibrillator device – (See "Perioperative management of patients with a pacemaker or implantable cardioverter-defibrillator", section on 'Emergency surgery' and "Perioperative management of patients with a pacemaker or implantable cardioverter-defibrillator", section on 'Evaluation'.)

•Assessing for actual or potential hemodynamic instability. Such patients may have an intraaortic balloon pump (IABP) in place, or the surgeon may plan to insert an IABP after inducing general anesthesia or before terminating cardiopulmonary bypass (CPB) (see "Intraaortic balloon pump counterpulsation"). However, use of an IABP is contraindicated if the patient has significant aortic regurgitation, as discussed separately. (See "Anesthesia for patients with aortic regurgitation", section on 'Acute aortic regurgitation' and "Intraaortic balloon pump counterpulsation".)

Other temporary mechanical circulatory assistance (eg, ventricular assist devices, extracorporeal mechanical oxygenator) may be in place, or their use may be planned. Management of these devices and the role of echocardiography during insertion and management are discussed in separate topics:

-(See "Short-term mechanical circulatory assist devices".)

-(See "Short-term left ventricular mechanical circulatory support: Use of echocardiography during initiation and management".)

-(See "Short-term right ventricular or biventricular mechanical circulatory support: Use of echocardiography during initiation and management".)

Emergency reversal of medications affecting hemostasis — Management of the ongoing effects of chronically or acutely administered medications affecting hemostasis may be necessary in patients undergoing urgent or emergency cardiac surgery.

●Antiplatelet agents – Bleeding risk is increased if patients recently received P2Y₁₂ antagonists (eg, due to unstable angina or after unsuccessful percutaneous coronary intervention) [8,9]. Intraoperative administration of platelets (typically 1 apheresis unit or 6 units of pooled platelets) may be necessary to overcome the effects of recently administered antiplatelet agents in patients with unacceptable microvascular bleeding, although supportive data are limited [9,10]. For patients who have received antiplatelet agents, preoperative communication with the blood bank to ensure platelet availability is prudent.

●Anticoagulant agents – If discontinuation of anticoagulant agents is not possible (eg, emergency coronary artery bypass grafting [CABG] surgery in a patient chronically receiving anticoagulant agents), then urgent anticoagulant reversal may be necessary if there are no contraindications [11,12].

•Warfarin – For warfarin, a 4-factor prothrombin complex concentrate (PCC) product is the preferred treatment for emergency reversal of anticoagulation with a vitamin K antagonist, rather than reversal with fresh frozen plasma (table 1 and table 2) [13]. Also, concomitant vitamin K is administered together with the PCC since any PCC has a limited duration of action.

•Direct oral anticoagulants (DOACs) – DOACS that inhibit thrombin or factor Xa have shorter half-lives than warfarin; nevertheless, reversal strategies for DOACs may be necessary for urgent and emergency procedures (table 3). We avoid andexanet alfa for reversal of DOACs because administration of this agent can result in significant heparin resistance in patients undergoing CPB [14].

Details regarding the management of these agents for urgent or emergency cardiac surgical procedures are available in separate topics:

•(See "Perioperative management of patients receiving anticoagulants", section on 'Urgent/emergency invasive procedure'.)

•(See "Management of warfarin-associated bleeding or supratherapeutic INR".)

•(See "Management of bleeding in patients receiving direct oral anticoagulants".)

Management of anticoagulants in patients with prosthetic heart valves is discussed separately. (See "Anticoagulation for prosthetic heart valves: Management of bleeding and invasive procedures", section on 'Procedures with more than minimal risk of bleeding'.)

●Thrombolytic agents – In patients undergoing emergency CABG surgery after receiving thrombolytic (fibrinolytic) agents during failed attempts to manage acute ST elevation myocardial infarction (MI), it may be necessary to increase fibrinogen levels with administration of fibrinogen concentrates or transfusion of cryoprecipitate or plasma, in addition to administering an antifibrinolytic agent (eg, aminocaproic acid or tranexamic acid). Discussions regarding preoperative management of emergency surgery in such patients are available in separate topics:

•(See "Anticoagulation and blood management strategies during cardiac surgery with cardiopulmonary bypass", section on 'Antifibrinolytic administration'.)

•(See "Achieving hemostasis after cardiac surgery with cardiopulmonary bypass", section on 'Treatments to improve hemostasis' and "Achieving hemostasis after cardiac surgery with cardiopulmonary bypass", section on 'Other hemostatic agents for bleeding post-bypass'.)

Transport to the operating room — Ensure availability of experienced personnel who are familiar with any specialized equipment used during transport (eg, mechanical circulatory support devices). (See "Transport of surgical patients", section on 'Management of mechanical circulatory support devices'.)

In rare cases, a patient may be undergoing cardiopulmonary resuscitation (CPR) during emergency transport to an operating room. In such cases, CPR must be continued during transport. (See "Transport of surgical patients", section on 'Ongoing cardiopulmonary resuscitation'.)

INTRAOPERATIVE CONSIDERATIONS — 

General considerations for emergency or high-risk cases include:

Preinduction considerations

●Establish intravenous (IV) and intra-arterial access. It is critically important to establish IV access adequate for fluid resuscitation and transfusions if not already available, as well as intra-arterial access for continuous monitoring of arterial blood pressure. The intra-arterial catheter is ideally inserted before rather than after induction of general anesthesia.

Other monitors (eg, central venous catheter [CVC] and transesophageal echocardiography [TEE]) are typically inserted after induction of anesthesia. Monitoring details are discussed separately. (See "Anesthesia for cardiac surgery: General principles", section on 'Monitoring'.)

●For patients with an ICD device, reprogramming to suspend anti-tachyarrhythmia therapy is accomplished before surgical incision, if possible. In emergencies, a sterile magnet (or a magnet encased in a sterile sheath) may be used in the surgical field to disable the anti-tachycardia function. Since pacing function will be lost during electromagnetic interference (EMI), short electrocautery bursts must be used to prevent hypotension in patients who are pacing-dependent. Details are discussed in a separate topic. (See "Perioperative management of patients with a pacemaker or implantable cardioverter-defibrillator", section on 'Emergency surgery'.)

●Place external defibrillator pads on the patient prior to induction. A functioning pacemaker/defibrillator should be ready at the bedside. If atrial or ventricular fibrillation occur, appropriate and immediate cardioversion or defibrillation is typically necessary. Exceptions include full circulatory support with biventricular assist devices or extracorporeal mechanical oxygenation, or the ability of the surgical team to rapidly insert arterial and venous cannulae to initiate cardiopulmonary bypass (CPB).

●Connect inotropic and vasopressor infusions in the CVC ports to be ready to infuse during induction.

●Consider prepping and draping before anesthetic induction. In some cases, prepping and draping in preparation for surgery should be completed while the patient is still awake, with the entire operating room team present and ready to urgently establish CPB if cardiac arrest occurs during anesthetic induction.

Anesthetic induction and the prebypass period

●Select agents that cause minimal change in hemodynamics during induction of general anesthesia. Examples include etomidate 0.3 mg/kg or fentanyl 5 to 10 mcg/kg combined with midazolam 0.05 to 0.1 mg/kg. Rapid sequence induction and intubation may be necessary for patients who have a full stomach. (See "Rapid sequence induction and intubation (RSII) for anesthesia".)

Anesthesia is subsequently maintained during the pre-bypass period with appropriate doses of volatile inhalation anesthetic.

●Maintain hemodynamic stability during the pre-bypass period. Typically, vasoactive drug infusions are required to maintain adequate blood pressure and cardiac output (table 4). Atrial pacing may be necessary to establish the optimum heart rate, or atrioventricular (AV) pacing may be necessary if heart block is present.

●Facilitate safe initiation of CPB as quickly as possible. Ensure that heparin is administered into a functioning IV catheter with thorough flushing into the patient for systemic anticoagulation. This is especially important if it becomes necessary to initiate emergency CPB before the activated whole blood clotting time (ACT) measurement that has been initiated has reached the targeted value (typically ≥400 to 480 seconds). Details are discussed in separate topics. (See "Anticoagulation and blood management strategies during cardiac surgery with cardiopulmonary bypass", section on 'Heparin administration and monitoring' and "Initiation of cardiopulmonary bypass".)

Postbypass considerations — Postbypass problems should be anticipated. These may include (see "Intraoperative problems after cardiopulmonary bypass"):

●Left ventricular (LV) dysfunction may be present due to preexisting chronic ventricular dysfunction that was exacerbated by myocardial ischemia, stunning, or ischemia/reperfusion injury (see "Intraoperative problems after cardiopulmonary bypass", section on 'Left ventricular dysfunction'). Treatment with inotropic drug therapy or combination therapy with positive inotropic and vasodilator agents to optimize cardiac index (CI) may be necessary (see "Intraoperative problems after cardiopulmonary bypass", section on 'Vasoactive drug therapy'). Postcardiotomy shock that is refractory to pharmacologic therapy may require management with temporary mechanical circulatory support (eg, intraaortic balloon pump [IABP] counterpulsation, ventricular assist device [VAD]). (See "Intraoperative problems after cardiopulmonary bypass", section on 'Short-term mechanical circulatory assist devices'.)

●Cardiogenic pulmonary edema may be present in patients who had preoperative acute heart failure; this can be exacerbated by inflammatory processes and excess fluid administration during CPB. Management is discussed separately. (See "Intraoperative problems after cardiopulmonary bypass", section on 'Pulmonary edema'.)

●Significant bleeding and coagulopathy is likely in patients who were chronically receiving medications affecting hemostasis, as noted above (see 'Emergency reversal of medications affecting hemostasis' above). Management is discussed separately. (See "Achieving hemostasis after cardiac surgery with cardiopulmonary bypass".)

Transport to the intensive care unit — Hemostasis and hemodynamic stability must be achieved prior to transport from the operating room to the intensive care unit (ICU). Details are discussed in separate topics:

●(See "Anesthesia for cardiac surgery: General principles", section on 'Preparation for transport'.)

●(See "Transport of surgical patients", section on 'Transport of critically ill patients'.)

●(See "Handoffs of surgical patients", section on 'Operating room to intensive care unit'.)

SPECIAL POPULATIONS

Emergency cardiac surgery during pregnancy — Certain acute cardiac events result in life-threatening hemodynamic instability in the parturient. Examples include acute aortic dissection (see 'Acute aortic dissection' below), acute onset of severe mitral or aortic regurgitation due to endocarditis, acute myocardial infarction (MI), acute prosthetic cardiac valve thrombosis or dysfunction, and pulmonary embolism. In such cases, immediate cardiovascular surgical intervention with cardiopulmonary bypass (CPB) may be necessary.

It is important that the pregnancy does not delay life-saving treatment for the mother. If the fetus is viable, the cardiac surgical procedure may be combined with cesarean delivery.

Acute aortic dissection — Emergency surgical repair is necessary for acute ascending (type A) aortic dissection (movie 1 and image 1 and figure 1). Surgical and preanesthetic evaluation and preparation are expedited so that induction of general anesthesia can proceed without delay, as risk for complications such as acute aortic regurgitation, cardiac tamponade, stroke, or MI is estimated to be as high as 1 to 2 percent per hour after symptom onset [6].

Factors that increase risk and affect anesthetic and surgical management may include [6,15]:

●Acute aortic regurgitation (AR) – Acute AR may occur as a consequence of dissection involving the aortic root. Patients with acute AR typically present with tachycardia and decompensated heart failure due to a sudden increase in left ventricular (LV) diastolic pressure. Beta-blocker therapy to control heart rate (HR) or blood pressure (BP) is withheld or administered cautiously to prevent cardiogenic shock in a patient with acute AR. (See "Anesthesia for patients with aortic regurgitation", section on 'Acute aortic regurgitation'.)

Additional considerations for patients with significant AR are applicable during CPB.

●Cardiac tamponade – Cardiac tamponade is a common complication of type A aortic dissection (figure 1). The aortic root and the first 11 cm of the ascending aorta lie within the pericardial sac; thus, a contained rupture of the aortic root or proximal ascending aorta may result in hemopericardium with tamponade. Signs of cardiac tamponade may be noted on physical examination (eg, distended neck veins), hemodynamic monitoring (eg, pulsus paradoxus), or with the presence of blood in the pericardial space may be visualized on the preoperative computed tomography (CT) scan or echocardiogram. (See "Anesthesia for patients with pericardial disease and/or cardiac tamponade", section on 'Assessing diagnostic tests'.)

Severity of cardiac tamponade is assessed with preoperative transthoracic echocardiography (TTE) but may worsen during preoperative evaluation. Thus, severity is reassessed with intraoperative transesophageal echocardiography (TEE) after induction of general anesthesia. (See "Anesthesia for aortic surgery with hypothermia and elective circulatory arrest in adult patients", section on 'Transesophageal echocardiography'.)

As noted above for patients with acute AR, beta-blocker therapy is withheld in a patient with cardiac tamponade to prevent cardiogenic shock.

●Malperfusion of extremities – Aortic branch vessels involved in the dissection or perfused from the false lumen of the aorta may result in limb malperfusion that determines which sites are suitable for intra-arterial catheter insertion for continuous monitoring of BP (see "Anesthesia for aortic surgery with hypothermia and elective circulatory arrest in adult patients", section on 'Intra-arterial catheter'), as well as for arterial cannulation for CPB. Malperfusion may manifest as a pulse deficit on physical examination or be noted as decreased flow on the arterial phase of the preoperative CT angiogram.

●Acute stroke – Malperfusion or dissection of the aortic arch vessels may cause an acute stroke [16]. Preoperative or intraoperative surface vascular ultrasound or carotid artery duplex imaging may be used to diagnose extension of the dissection into the common carotid arteries and to assess blood flow in these arteries.

●Acute coronary syndrome – Acute coronary syndrome, most often involving the right coronary artery, may occur due to coronary dissection or malperfusion, with consequent inferior wall and right ventricular (RV) dysfunction, MI, or biventricular failure.

●Acute mesenteric ischemia – Acute visceral ischemia may manifest as acute kidney injury or abdominal pain with melena. Kidney risk mitigation during cardiac surgery is discussed separately. (See "Management of special populations during cardiac surgery with cardiopulmonary bypass", section on 'Chronic kidney disease and renal risk mitigation'.)

●Acute spinal cord ischemia – Rarely, aortic intramural hematoma may cause spinal cord ischemia with paraparesis/paraplegia [17].

●Consequences of deep hypothermia – Many procedures involving the ascending aorta or aortic arch require temporary interruption of cerebral and systemic blood flow. Deliberate deep hypothermia and (elective) circulatory arrest (DHCA) may be employed to perform these procedures. Consequences of this technique include:

•Coagulopathy – Acute type A aortic dissection is associated with preoperative coagulopathy that worsens during and after surgery, particularly if a technique that includes a period of DHCA is employed [18]. Reasons for this include anti-hemostatic effects of deep hypothermia, ischemia and reperfusion injury due to elective circulatory arrest, and fibrinolysis and platelet activation after a prolonged duration of CPB. Persistent bleeding, anemia, thrombocytopenia, and coagulopathy may occur in this setting. Management is addressed in separate topics:

-(See "Anesthesia for aortic surgery with hypothermia and elective circulatory arrest in adult patients", section on 'Control of coagulopathy to achieve hemostasis'.)

-(See "Achieving hemostasis after cardiac surgery with cardiopulmonary bypass".)

•Episodes of hypertension and/or hypotension — During the post-bypass period, both hypertension and hypotension are common after aortic surgery with DHCA. Management is discussed separately. (See "Anesthesia for aortic surgery with hypothermia and elective circulatory arrest in adult patients", section on 'Control of blood pressure'.)

Revascularization for acute MI — Emergency coronary artery bypass graft (CABG) surgery is necessary in selected patients with acute ST-elevation myocardial infarction (STEMI). Indications, optimal timing, technical considerations, and outcomes of urgent or emergency CABG in these patients are described in detail in a separate topic. (See "Coronary artery bypass graft surgery in patients with acute ST-elevation myocardial infarction".)

Cardiac trauma — Penetrating thoracic injury may result in cardiac trauma with cardiac tamponade. Details regarding the initial anesthetic management of patients with pericardial tamponade are noted in the algorithm (algorithm 1), and in separate topics:

●(See "Initial evaluation and management of penetrating thoracic trauma in adults", section on 'Cardiac injury'.)

●(See "Anesthesia for thoracic trauma in adults".)

After cardiac trauma, the RV is the most commonly injured chamber due to its anterior position within the chest cavity. The next most commonly injured chamber is the LV. Atrial injuries are less common, but can be equally or more severe due to the thin nature of the atrial wall that cannot “close” around a penetrating injury as effectively as the thick-walled LV.

Cardiac tamponade may also occur after blunt chest trauma, most commonly due to rupture of the right atrial appendage. In such cases, emergency cardiac surgery is necessary to repair the injured cardiac chamber. These injuries are discussed in a separate topic. (See "Initial evaluation and management of blunt cardiac injury".)

Anesthetic management of patients with cardiac trauma is discussed in detail in separate topics:

●(See "Anesthesia for thoracic trauma in adults".)

●(See "Anesthesia for patients with pericardial disease and/or cardiac tamponade".)

Infective endocarditis — Indications for emergency cardiac valve surgery for infective endocarditis are discussed in a separate topic. (See "Overview of management of infective endocarditis in adults", section on 'Role of valve surgery'.)

When early surgery is indicated, it should not be delayed except for patients with major cerebrovascular complications (eg, hemorrhagic stroke) or those with high operative risk or poor long-term prognosis due to other medical problems. Specific management considerations for left-sided or right-sided native cardiac valve endocarditis, and for prosthetic valve endocarditis, are discussed in separate topics:

●(See "Surgery for left-sided native valve infective endocarditis".)

●(See "Right-sided native valve infective endocarditis", section on 'Surgical assessment'.)

●(See "Prosthetic valve endocarditis: Surgical management".)

SOCIETY GUIDELINE LINKS — 

Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Management of cardiopulmonary bypass".)

SUMMARY AND RECOMMENDATIONS

●Preoperative considerations

•Preoperative assessment – Important issues include (see 'Preoperative assessment' above):

-Assessing cardiac pathophysiology.

-Checking recent laboratory values and ordering tests that are missing. (See "Evaluation of cardiac risk prior to noncardiac surgery".)

-Checking the availability of blood products. For rapid bleeding, "emergency release" blood (typically group O) may be necessary for immediate transfusion. (See "Pretransfusion testing for red blood cell transfusion", section on 'Emergency release blood for life-threatening anemia or bleeding'.)

-Determining allergies, fasting status, relevant medical and surgical history, problems with prior anesthetics, recently administered medications, presence of an implantable cardioverter-defibrillator device.

-Assessing for actual or potential hemodynamic instability.

•Emergency reversal of medications affecting hemostasis

-Antiplatelet agents – If P2Y₁₂ antagonists were recently administered, preoperative communication with the blood bank is prudent to ensure platelet availability (typically 1 apheresis unit or 6 units of pooled platelets) for potential unacceptable microvascular bleeding.

-Anticoagulant agents – For patients chronically receiving warfarin, emergency reversal with a 4-factor prothrombin complex concentrate (PCC) product administered together with a vitamin K antagonist is preferred, rather than reversal with fresh frozen plasma (table 1 and table 2).

Other reversal strategies for direct oral anticoagulants (DOACs) are noted in the tables (table 3) and are discussed in separate topics:

(See "Perioperative management of patients receiving anticoagulants", section on 'Urgent/emergency invasive procedure'.)

(See "Management of warfarin-associated bleeding or supratherapeutic INR".)

(See "Management of bleeding in patients receiving direct oral anticoagulants".)

-Fibrinolytic agents – After receiving fibrinolytic (thrombolytic) agents, increasing fibrinogen levels by administering fibrinogen concentrates or transfusion of cryoprecipitate or plasma may be necessary, in addition to administering an antifibrinolytic agent (eg, aminocaproic acid or tranexamic acid). Details are discussed in separate topics:

(See "Achieving hemostasis after cardiac surgery with cardiopulmonary bypass".)

(See "Anticoagulation and blood management strategies during cardiac surgery with cardiopulmonary bypass", section on 'Antifibrinolytic administration'.)

•Transportation to the operating room – Transport of critically ill patients is discussed separately. (See "Transport of surgical patients", section on 'Transport of critically ill patients'.)

●Preinduction considerations – (See 'Preinduction considerations' above.)

•Establish intravenous (IV) and intra-arterial access. The intra-arterial catheter is ideally inserted before the induction of general anesthesia. Other catheters (eg, central venous catheter [CVC] are typically inserted after induction.

•Manage an implantable cardioverter defibrillator device (ICD). Details are discussed separately. (See "Perioperative management of patients with a pacemaker or implantable cardioverter-defibrillator", section on 'Emergency surgery'.)

•Place external defibrillator pads prior to induction. A functioning pacemaker/defibrillator should be ready at the bedside.

•Connect inotropic and vasopressor infusions in the CVC ports before induction.

•Consider prepping and draping before anesthetic induction.

●Anesthetic induction and the prebypass period – (See 'Anesthetic induction and the prebypass period' above.)

•Select induction agents that cause minimal change in hemodynamics.

•Maintain hemodynamic stability before cardiopulmonary bypass (CPB).

•Facilitate safe initiation of CPB as quickly as possible. Ensure heparin administration into a functioning IV catheter with thorough flushing to establish systemic anticoagulation, as discussed in separate topics. (See "Anticoagulation and blood management strategies during cardiac surgery with cardiopulmonary bypass", section on 'Heparin administration and monitoring' and "Initiation of cardiopulmonary bypass".)

•Postbypass considerations – Postbypass problems are common, as discussed separately. (See "Intraoperative problems after cardiopulmonary bypass".)

•Transport to the intensive care unit – Transport to the intensive care unit is discussed in separate topics:

-(See "Anesthesia for cardiac surgery: General principles", section on 'Preparation for transport'.)

-(See "Transport of surgical patients", section on 'Transport of critically ill patients'.)

-(See "Handoffs of surgical patients", section on 'Operating room to intensive care unit'.)

●Special populations

•Pregnancy – Acute cardiac events and life-threatening hemodynamic instability in a pregnant patient may require emergency cardiovascular surgical intervention. Concomitant cesarean delivery may be performed for a viable fetus. (See 'Emergency cardiac surgery during pregnancy' above.)

•Acute aortic dissection – Risks for patients requiring emergency surgical repair for acute ascending (type A) aortic dissection (movie 1 and image 1 and figure 1) are discussed in other topics:

-Acute aortic regurgitation (AR) – (See "Anesthesia for patients with aortic regurgitation", section on 'Acute aortic regurgitation'.)

-Cardiac tamponade – (See "Anesthesia for patients with pericardial disease and/or cardiac tamponade", section on 'Assessing diagnostic tests'.)

-Malperfusion of extremities – (See "Anesthesia for aortic surgery with hypothermia and elective circulatory arrest in adult patients", section on 'Intra-arterial catheter'.)

-Acute stroke

-Acute coronary syndrome – (See "Intraoperative problems after cardiopulmonary bypass", section on 'Left ventricular dysfunction'.)

-Acute mesenteric ischemia – (See "Management of special populations during cardiac surgery with cardiopulmonary bypass", section on 'Chronic kidney disease and renal risk mitigation'.)

-Acute spinal cord ischemia

-Consequences of deep hypothermia (eg, coagulopathy, episodes of hypertension and/or hypotension. (See "Anesthesia for aortic surgery with hypothermia and elective circulatory arrest in adult patients", section on 'Problems in the postbypass period'.)

•Revascularization for acute myocardial infarction – Considerations are discussed separately. (See "Coronary artery bypass graft surgery in patients with acute ST-elevation myocardial infarction".)

•Cardiac trauma – Anesthetic management of patients with cardiac trauma is discussed in separate topics:

-(See "Anesthesia for thoracic trauma in adults".)

-(See "Anesthesia for patients with pericardial disease and/or cardiac tamponade".)

•Infective endocarditis – Considerations for emergency cardiac valve surgery are discussed separately. (See "Overview of management of infective endocarditis in adults", section on 'Role of valve surgery'.)