Percutaneous cardiopulmonary bypass for cardiac emergencies

Clinical and Angiographic Features of Patients With Out-of-Hospital Cardiac Arrest and Acute Myocardial Infarction

BACKGROUND

Sudden cardiac arrest is a serious complication of acute myocardial infarction (MI). Although in-hospital mortality from MI has decreased, the mortality of MI patients complicated with out-of-hospital cardiac arrest (OHCA) remains high. However, the features of acute MI patients with OHCA have not been well known.

OBJECTIVES

We sought to characterize the clinical and angiographic features of acute MI patients with OHCA comparing with those without OHCA.

METHODS

We retrospectively analyzed 480 consecutive patients with acute MI undergoing percutaneous coronary intervention. Patients complicated with OHCA were compared with patients without OHCA.

RESULTS

Of the patients, 141 (29%) were complicated with OHCA. Multivariate analysis revealed that age (odds ratio [OR]: 0.8; 95% confidence interval [CI]: 0.7 to 0.9 per 5 years; p < 0.001), estimated glomerular filtration rate (OR: 0.8; 95% CI: 0.7 to 0.8 per 10 ml/min/1.73 m²; p < 0.001), peak creatine kinase-myocardial band (OR: 1.3; 95% CI: 1.2 to 1.4 per 10² U/l; p < 0.001), calcium-channel antagonists use (OR: 0.4; 95% CI: 0.2 to 0.7; p = 0.002), the culprit lesion at the left main coronary artery (OR: 5.3; 95% CI: 1.9 to 15.1; p = 0.002), and the presence of chronic total occlusion (OR: 2.9; 95% CI: 1.5 to 5.7; p = 0.001) were significantly associated with OHCA.

CONCLUSIONS

Younger age, no use of calcium-channel antagonists, worse renal function, larger infarct size, culprit lesion in the left main coronary artery, and having chronic total occlusion were associated with OHCA.

Extracorporeal life support for adults with refractory septic shock

OBJECTIVE

Although the use of extracorporeal membrane oxygenation (ECMO) in shock patients is increasing worldwide, studies concerning this treatment for adult septic shock are limited. This study aimed to analyze the outcome of venoarterial ECMO in adult patients with septic shock refractory to conventional treatment.

METHODS

A total of 71 consecutive patients who presented with septic shock and underwent venoarterial ECMO were reviewed. Clinical parameters were compared between survivors and nonsurvivors. Weaning and survival outcomes of these patients were compared with the control group of 253 patients who received venoarterial ECMO for cardiogenic shock.

RESULTS

The mean age was 56.0 ± 12.3 years. Of the 71 septic shock patients, 11 (15.5%) were successfully weaned from ECMO after a median of 7.9 [interquartile range (IQR), 6.3-10.2] days, 5 of whom (7.0%) survived to discharge. Pre- and 6 hours post-procedural lactate levels were significantly higher in the nonsurvivors (11.6 [IQR, 7.5-15.0] vs 5.8 [IQR, 4.3-5.9], P = .036; 15.0 [IQR, 11.1-15.0] vs 5.2 [IQR, 4.7-5.4], P = .002). Rates of successful weaning from venoarterial ECMO (15.5% vs 45.5%), and of survival up to hospital discharge (7.0% vs 28.9%) were significantly lower in septic shock than in cardiogenic shock patients (n = 253; P < .001).

CONCLUSIONS

Outcomes of ECMO in refractory septic shock patients were poor with a very low probability of survival. This finding raises questions concerning the utility of applying ECMO for medically refractory septic shock. Elevated arterial lactate levels pre- and post-ECMO were associated with risk of in-hospital death. Further large-scale studies are needed to validate the results of this study.

Advanced Age as a Predictor of Survival and Weaning in Venoarterial Extracorporeal Oxygenation: A Retrospective Observational Study

Background. In most reports on ECMO treatment, advanced age is classified as a contraindication to VA ECMO. We attempted to investigate whether advanced age would be a main risk factor deciding VA ECMO application and performing VA ECMO support. We determined whether advanced age should be regarded as an absolute or relative contraindication to VA ECMO and could affect weaning and survival rates of VA ECMO patients. Methods. VA ECMO was performed on 135 adult patients with primary cardiogenic shock between January 2010 and December 2014. Successful weaning was defined as weaning from ECMO followed by survival for more than 48 hours. Results. Among the 135 patients, 35 survived and were discharged uneventfully, and the remaining 100 did not survive. There were significant differences in survival between age groups, and older age showed a lower survival rate with statistical significance (P = .01). By multivariate logistic regression analysis, age was not significantly associated with in-hospital mortality (P = .83) and was not significantly associated with VA ECMO weaning (P = .11). Conclusions. Advanced age is an undeniable risk factor for VA ECMO; however, patients of advanced age should not be excluded from the chance of recovery after VA ECMO treatment.

Five-year Experience of Extracorporeal Life Support in Emergency Physicians

Background

This study aimed to present our 5-year experience of extracorporeal cardiopulmonary resuscitation (ECPR) performed by emergency physicians.

Methods

We retrospectively analyzed 58 patients who underwent ECPR between January 2010 and December 2014. The primary parameter analyzed was survival to hospital discharge. The secondary parameters analyzed were neurologic outcome at hospital discharge, cannulation time, and ECPR-related complications.

Results

Thirty-one patients (53.4%) were successfully weaned from extracorporeal membrane oxygenation, and 18 (31.0%) survived to hospital discharge. Twelve patients (20.7%) were discharged with good neurologic outcomes. The median cannulation time was 25.0 min (interquartile range 20.0-31.0 min). Nineteen patients (32.8%) had ECPR-related complications, the most frequent being distal limb ischemia. Regarding the initial presentation, 52 patients (83.9%) collapsed due to a cardiac etiology, and acute myocardial infarction (33/62, 53.2%) was the most common cause of cardiac arrest.

Conclusions

The survival to hospital discharge rate for cardiac arrest patients who underwent ECPR conducted by an emergency physician was within the acceptable limits. The cannulation time and complications following ECPR were comparable to those found in previous studies.

Single, percutaneous, femoral venous cannulation for cardiopulmonary bypass

Percutaneous femoral venous cannulation for cardiopulmonary bypass has emerged as an indispensable technique in the management of cardiac surgical procedures requiring cardiopulmonary bypass. A review of cases at Brigham and Women's Hospital (Boston, MA, USA) relying solely on percutaneous femoral venous cannulation for venous return to the heart-lung machine demonstrated achievable blood flow and complexity of case-load. Operations performed in this manner include, but are not limited to, coronary artery bypass grafting (CABG), valve, CABG/valve, and aortic procedures. Minimally invasive procedures and re-operations comprise a portion of each group. Complications of cardiopulmonary bypass and site-related complications were considered. Percutaneous femoral venous cannulation is a safe method to provide most patients with adequate venous return to perform any cardiac surgery. Patients demanding greater flow than this method will provide, may require a second venous cannula at some time during cardiopulmonary bypass. Perfusion (2007) 22, 211—215.

The pre-ECMO simplified acute physiology score II as a predictor for mortality in patients with initiation ECMO support at the emergency department for acute circulatory and/or respiratory failure: a retrospective study

Background

In the emergency department (ED), extracorporeal membrane oxygenation (ECMO) can be used as a rescue treatment modality for patients with refractory circulatory and/or respiratory failure. Serious consideration must be given to the indication, and the PRESERVE and RESP scores for mortality have been investigated. However these scores were validated to predict survival in patients who received mainly veno-venous (VV) ECMO in the intensive care unit. The aim of the present study was to investigate the factors that predicted the outcomes for patients who received mixed mode (veno-arterial [VA] and VV) ECMO support in the ED.

Methods

This single center retrospective study included 65 patients who received ECMO support at the ED for circulatory or respiratory failure between January 2009 and December 2013. Pre-ECMO SAPS II and other variables were evaluated and compared for predicting mortality.

Results

Fifty-four percent of patients received ECMO-cardiopulmonary resuscitation (E-CPR), 31 % received VA and V-AV ECMO, and 15 % received VV ECMO. The 28-day and 60-month mortality rates were 52 % and 63 %. In the multivariate analysis, only the pre-ECMO Simplified Acute Physiology Score II (SAPS II) (odd ratio: 1.189, 95 % confidence interval: 1.032–1.370, p = 0.016) could predict the 28-day mortality. The area under the receiver operating characteristic curve and the optimal cutoff value for pre-ECMO SAPS II in predicting 28-day mortality was 0.852 (95 % CI: 0.753–0.951, p < 0.001) and 80 (sensitivity of 97.1 % and specificity of 71.0 %), respectively. Validation of the 80 cutoff value revealed a statistically significant difference for the 28-day and 60-month mortality rates in the overall, E-CPR, and VA groups (28-day: p < 0.001, p = 0.004, p = 0.005; 60-month: p < 0.001, p = 0.004, p = 0.020). In the Kaplan-Meier analysis, the 28-day and 60-month survival rates were lower among the patients with a pre-ECMO SAPS II of ≤80, compared to those with a score of >80 (both, p < 0.001).

Conclusion

The pre-ECMO SAPS II could be helpful for identifying patients with refractory acute circulatory and/or respiratory failure who will respond to ECMO support in the ED.

Percutaneous cardiopulmonary support to treat suspected venous air embolism with cardiac arrest during open eye surgery: a case report

We report a case of possible venous air embolism (VAE) during trans pars plana vitrectomy with air-fluid exchange of the vitreous cavity. Shortly after initiation of air-fluid exchange, decreases in end-tidal CO2, oxygen saturation, and blood pressure were observed. The patient rapidly progressed to cardiac arrest unresponsive to cardiopulmonary resuscitation, and recovered after the application of percutaneous cardiopulmonary support. Prompt termination of air infusion is needed when VAE is suspected during air-fluid exchange, and extracorporeal life support should be considered in fatal cases. Although the incidence is rare the possibility of VAE during ophthalmic surgery clearly exists, and therefore awareness and vigilant monitoring seem critical.

Full neurologic recovery and return of spontaneous circulation following prolonged cardiac arrest facilitated by percutaneous left ventricular assist device

Sudden cardiac arrest is associated with high early mortality, which is largely related to postcardiac arrest syndrome characterized by an acute but often transient decrease in left ventricular (LV) function. The stunned LV provides poor cardiac output, which compounds the initial global insult from hypoperfusion. If employed early, an LV assist device (LVAD) may improve survival and neurologic outcome; however, traditional methods of augmenting LV function have significant drawbacks, limiting their usefulness in the periarrest period. Full cardiac support with cardiopulmonary bypass is not always readily available but is increasingly being studied as a tool to intensify resuscitation. There have been no controlled trials studying the early use of percutaneous LVADs (pLVADs) in pericardiac arrest patients or intra-arrest as a bridge to return of spontaneous circulation. This article presents a case study and discussion of a patient who arrested while undergoing an elective coronary angioplasty and suffered prolonged cardiopulmonary resuscitation. During resuscitation, treatment included placement of a pLVAD and initiation of therapeutic hypothermia. The patient made a rapid and full recovery.

Might rapid implementation of cardiopulmonary bypass in patients who are failing to recover after a cardiac arrest potentially save lives?

The question addressed was whether it might be beneficial to have a rapid-response emergency cardiopulmonary bypass service for patients who suffer an in-hospital or an out-of-hospital cardiac arrest of any aetiology. Eighty-five papers were reviewed using the reported search, of which 15 represented the best evidence to answer the clinical question. The authors, journal, date, country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. The concept of using emergency cardiopulmonary bypass (ECPB) for the management of cardiogenic shock and refractory cardiac arrest was developed in the late 1990s. Since this time, a large number of centres worldwide have reported success with use of ECPB for cardiac arrest refractory to conventional resuscitation techniques and for cardiogenic shock. This is a relatively new advancement in resuscitative strategy and is expanding in clinical practice. Clinical studies and experimental data reveal that ECPB is a very effective tool in the return of spontaneous circulation following refractory cardiac arrest. Resuscitation with this technique demonstrated survival benefit when compared with patients having conventional cardiopulmonary resuscitation for >10 min after witnessed in-hospital arrest, especially if the cause of arrest is of cardiac origin. The reported finding from a systematic review of 1494 patients treated with ECPB noted that the overall survival rate was 47.4%; their results indicate that the application of ECPB in cardiac arrest improves survival and the likelihood of a satisfactory neurological outcome. An additional review revealed that acceptable survival rate and neurological outcomes (30%) can be achieved with extracorporeal cardiopulmonary resuscitation in children after prolonged cardiac arrest (up to 95 min) refractory to standard resuscitation. However, no study has provided clear-cut evidence of the merits of ECPS in patients with out-of-hospital cardiac arrest, although many case reports and case series have concluded that it is an effective method. We conclude that institution of emergency cardiopulmonary bypass may save the lives of patients in whom routine attempts at resuscitation after a cardiac arrest fail, especially after >10 min. The likelihood of success is much higher for patients who have in-hospital witnessed cardiac arrest.

Extracorporeal Life Support After Prolonged Resuscitation for In-Hospital Cardiac Arrest due to Refractory Ventricular Fibrillation: Two Cases Resulting in a Full Recovery

Extracorporeal life support (ECLS) has well demonstrated its efficacy in treating in-hospital cardiac arrest and is being used for broader indications. However, ECLS after prolonged cardiopulmonary resuscitation (CPR) has been traditionally contraindicated and is now challenging. Here, we introduce two cases of successful ECLS after prolonged CPR, resulting in a immediate and full recovery. Both these acute ST elevation myocardial infarction patients waiting for primary percutaneous coronary intervention (PCI) suddenly collapsed due to ventricular fibrillation (VF), which was refractory to conventional treatment. After 2 hours of conventional CPR, the ECLS had been implemented and primary PCI could be performed. Subsequent to successful revascularization, the VF was stopped with a single electric shock. In our second case, normal sinus rhythm was spontaneously restored after ECLS implementation, which was completed after 45 minutes of conventional resuscitation. Both patients made a full neurological recovery on the day of the event and were discharged with only minor complications.

Management of the post-cardiac arrest syndrome

BACKGROUND

Recent advances in resuscitation science have revolutionized care of the cardiac arrest patient. Dramatic departures from time-honored advanced cardiac life support therapies, such as cardiocerebral resuscitation and bundled post-arrest care, have given rise to a new paradigm of resuscitation practices, which has boosted the rate of neurologically intact survival.

OBJECTIVES

This article reviews the pathophysiology of the post-cardiac arrest syndrome, the collective pathophysiology after return of spontaneous circulation, and presents management pearls specifically for the emergency physician. This growing area of scientific inquiry must be managed appropriately to sustain improved outcomes.

DISCUSSION

The emergency physician must understand this pathophysiology, manage resuscitated patients according to the latest evidence, and coordinate with appropriate inpatient resources.

CONCLUSION

The new approach to cardiac arrest care is predicated on a chain of survival that spans the spectrum of care from the prehospital arena through the emergency, intensive, and inpatient settings. The emergency physician is a crucial link in this chain.

Percutaneous cardiopulmonary support in refractory no-reflow with cardiogenic shock after coronary stenting in acute myocardial infarction

Coronary no-reflow is defined as inadequate myocardial perfusion of a given coronary segment without angiographic evidence of mechanical vessel obstruction. No-reflow is visualized angiographically as a reduction in thrombolysis in myocardial infarction (TIMI) flow grade and is typically accompanied by chest pain, electrocardiographic changes with ST-segment shift and possible hemodynamic compromise. No-reflow during primary percutaneous coronary intervention (PCI) results in increasing mortality and morbidity. Therefore, treatment of noreflow is associated with improved clinical outcomes. Generally, the treatment of no-reflow is based on pharmacotherapy. In this case, despite maximal pharmacotherapy and intraaortic balloon pump (IABP), refractory no-reflow accompanied with cardiogenic shock was successfully treated with percutaneous cardiopulmonary support (PCPS).

LIFEBRIDGE B2T--a new portable cardiopulmonary bypass system

The LIFEBRIDGE B2T is a new portable cardiopulmonary bypass (CPB) system designed for temporary circulatory support. The LIFEBRIDGE B2T consists of a disposable patient unit with a CPB circuit, a control, and a base unit. The system weighs 20 kg. We used the LIFEBRIDGE B2T in four patients for circulatory support in beating heart coronary artery bypass graft for complete revascularization. The LIFEBRIDGE B2T was connected via femoral cannulation. Concentrations of free hemoglobin (fHb), interleukin (IL)-6, and -8 were measured. For venous blood drainage, 22-24 Fr cannulae and for arterial cannulation, 16-20 Fr cannulae were used. Average extracorporeal circulation (ECC) time was 61 +/- 18 minutes. During circulatory support, the system delivered an arterial blood flow between 3.1 and 4.1 L/min. The negative pressure at the venous drainage was between -79 and -45 mm Hg. During circulatory support, fHb concentration increased from 5.8 +/- 1.7 mg/dL to a maximum of 10.2 +/- 6.2 mg/dL. Also, IL-6 and -8 increased from 2.1 +/- 0.06 to 503.3 +/- 400.7 U/L and 5.9 +/- 0.9 to 66.5 +/- 46.8 U/L, respectively. The LIFEBRIDGE B2T is a new portable and safe circulatory support system. Connected via femoral cannulation, the system provides adequate arterial blood flow and an acceptable negative pressure at the venous cannula. The fHb concentration showed only a moderate increase during ECC.

Earlier application of percutaneous cardiopulmonary support rescues patients from severe cardiopulmonary failure using the APACHE III scoring system

Percutaneous cardiopulmonary support (PCPS) is a widely accepted treatment for severe cardiopulmonary failure. This system, which uses a percutaneous approach and autopriming devices, can be rapidly applied in emergency situations. We sought to identify the risk factors that could help predict in-hospital mortality, and to assess its outcomes in survivors. During a 2-yr period, 50 patients underwent PCPS for the treatment of severe cardiopulmonary failure, and of those, 22 (44%) were classified as survivors and 28 (56%) as non-survivors. We compared the 2 groups for risk factors of in-hospital mortality and to establish proper PCPS timing. Twenty patients underwent PCPS for acute myocardial infarction, 20 for severe cardiopulmonary failure after cardiac surgery, 7 for acute respiratory distress syndrome, and 3 for acute myocarditis. Multivariate analysis showed that an acute physiology, age, and chronic health evaluation (APACHE) III score >or=50 prior to PCPS was the only significant predictor of in-hospital mortality (P=0.001). Overall 18-month survival was 42.2%. Cox analysis showed patients with APACHE III scores >or=50 had a poor prognosis (P=0.001). Earlier application of PCPS, and other preemptive strategies designed to optimize high-risk patients, may improve patient outcomes. Identifying patients with high APACHE scores at the beginning of PCPS may predict in-hospital mortality. Survivors, particularly those with higher APACHE scores, may require more frequent follow-up to improve overall survival.

Post-cardiac arrest syndrome: Epidemiology, pathophysiology, treatment, and prognostication: A scientific statement from the International Liaison Committee on Resuscitation; the American Heart Association Emergency Cardiovascular Care Committee; the Council on Cardiovascular Surgery and Anesthesia; the Council on Cardiopulmonary, Perioperative, and Critical Care; the Council on Clinical Cardiology; the Council on Stroke (Part 1)

AIM OF THE REVIEW

To review the epidemiology, pathophysiology, treatment and prognostication in relation to the post-cardiac arrest syndrome.

METHODS

Relevant articles were identified using PubMed, EMBASE and an American Heart Association EndNote master resuscitation reference library, supplemented by hand searches of key papers. Writing groups comprising international experts were assigned to each section. Drafts of the document were circulated to all authors for comment and amendment.

RESULTS

The 4 key components of post-cardiac arrest syndrome were identified as (1) post-cardiac arrest brain injury, (2) post-cardiac arrest myocardial dysfunction, (3) systemic ischaemia/reperfusion response, and (4) persistent precipitating pathology.

CONCLUSIONS

A growing body of knowledge suggests that the individual components of the postcardiac arrest syndrome are potentially treatable.

[Percutaneous extracorporeal life support in acute severe hemodynamic collapses: single centre experience in 100 consecutive patients]

BACKGROUND

Extracorporeal life support (ECLS) is a circulatory assistance device that is increasingly used in adults undergoing cardiopulmonary arrest (CPA) or hemodynamic collapse when conventional therapies fail.

OBJECTIVES

To assess the feasibility and outcomes of 100 consecutive arteriovenous percutaneous ECLS procedures at the Grenoble University Hospital between January 2002 and September 2007.

METHODS

Monocentric descriptive registry with one-year prospective follow-up.

RESULTS

An ECLS device was successfully used in 93% of patients. Its indication was cardiogenic shock in 50% of the cases, CPA in 38% of the cases and unsuccessful weaning of cardiopulmonary bypass (CPB) after cardiothoracic surgery in 12% of the cases. Direct complications of ECLS were observed in 56% of patients, the most frequent being hemorrhage at the intravenous puncture site requiring red blood cell transfusions (26%), and lower limb ischemia (19%). Weaning from ECLS was achieved in 33 patients (44% cardiogenic shocks, 13% CPAs, 50% CPB weaning failures) and 20 patients were discharged from the hospital (26% cardiogenic shocks, 10.5% CPAs and 25% CPB weaning failures). All are still living without any serious sequelae (mean follow-up period of 16.8 months).

CONCLUSION

The use of ECLS in CPA patients, especially with cardiogenic shock, is feasible with satisfactory survival rates, given the extreme severity of their initial state.

Patient selection and therapeutic strategy for emergency percutaneous cardiopulmonary system in cardiopulmonary arrest patients

BACKGROUND

To clarify the appropriate application and therapeutic strategy for the percutaneous cardiopulmonary system (PCPS) in patients in cardiopulmonary arrest (CPA), the effects of the duration of cardiopulmonary resuscitation (CPR), diagnosis of underlying diseases, subsequent intervention and complications were retrospectively investigated for the correlation between discharge or death of patients. The patients were treated under an identical therapeutic PCPS protocol.

METHODS AND RESULTS

The 69 CPA patients [55 males (78.6%), 14 females; age, 55.0 +/-15.3 years; age range 15-79 years, 50 in-hospital CPA (I-CPA) and 19 out-of-hospital CPA (O-CPA) patients] were treated with emergency PCPS. The mean duration of CPR was 43.6 +/-37.4 min. Of 18 discharged patients (26.1%), 14 had I-CPA and 4 had O-CPA. Significant factors in the discharge of patients were confirmed diagnosis, subsequent treatment and prevention of complications associated with PCPS.

CONCLUSIONS

Appropriate patient selection for PCPS in cases of O-CPA is likely to give a similar survival rate as for I-CPA. Patient selection and reversibility of the underlying disease and clinical state after starting PCPS affect the prognosis. Aggressive diagnosis and therapy for the underlying disease and prevention of complications associated with PCPS are essential factors in successful discharge of patients. Patients with an unknown etiology are not expected to fully recover, despite PCPS.

Percutaneous cardiopulmonary support for the treatment of acute pulmonary embolism: summarized review of the literature in Japan including our own experience

BACKGROUND

Acute pulmonary embolism (APE) has high mortality. Some APEs with circulatory collapse or cardiopulmonary arrest have been treated by percutaneous cardiopulmonary support (PCPS) in Japan. But there have been no reports with a large number of series of APE treated with the use of PCPS.

METHODS AND RESULTS

We collected all the reported cases with acute thrombotic pulmonary embolism treated with PCPS before surgical embolectomy or those without surgical embolectomy in Japan, and assessed the effectiveness of PCPS. PCPS was combined with surgical embolectomy in 35% (68 of 193), thrombolytic therapy in 62% (120/193), and catheter therapy in 24% (46/193). The survival rate treated with PCPS was 73% (80% in surgical embolectomy, 71% in thrombolytic therapy, and 76% in catheter therapy). Logistic regression analysis showed that the mortality rate was elevated in cases with cardiopulmonary arrest (odds ratio [OR], 3.41; 95% confidence interval [CI], 1.52-7.67; p-value, 0.003) but not by surgical embolectomy (OR, 0.99; 95% CI, 0.39-2.53; p-value, 0.98), catheter therapy (OR, 0.71; 95% CI, 0.30-1.72; p-value, 0.45), and thrombolysis (OR, 1.60; 95% CI, 0.64-3.99; p-value, 0.31) as regards to the concomitant therapies with PCPS.

CONCLUSION

PCPS might improve the survival rate in APE patients with circulatory collapse or cardiopulmonary arrest, but there was no differences in outcome among cases treated by surgical embolectomy, catheter therapy, and thrombolysis as the concomitant therapies.

Post-cardiac arrest syndrome: epidemiology, pathophysiology, treatment, and prognostication. A Scientific Statement from the International Liaison Committee on Resuscitation; the American Heart Association Emergency Cardiovascular Care Committee; the Council on Cardiovascular Surgery and Anesthesia; the Council on Cardiopulmonary, Perioperative, and Critical Care; the Council on Clinical Cardiology; the Council on Stroke

AIM OF THE REVIEW

To review the epidemiology, pathophysiology, treatment and prognostication in relation to the post-cardiac arrest syndrome.

METHODS

Relevant articles were identified using PubMed, EMBASE and an American Heart Association EndNote master resuscitation reference library, supplemented by hand searches of key papers. Writing groups comprising international experts were assigned to each section. Drafts of the document were circulated to all authors for comment and amendment.

RESULTS

The 4 key components of post-cardiac arrest syndrome were identified as (1) post-cardiac arrest brain injury, (2) post-cardiac arrest myocardial dysfunction, (3) systemic ischaemia/reperfusion response, and (4) persistent precipitating pathology.

CONCLUSIONS

A growing body of knowledge suggests that the individual components of the post-cardiac arrest syndrome are potentially treatable.

Cardiopulmonary bypass as an adjunct for the noncardiac surgeon

The use of cardiopulmonary bypass (CPB) in noncardiac surgical settings has been increasingly developed and has greatly benefited noncardiac surgeon. A few years after the advent of CPB as well as profound hypothermic circulatory arrest in the early years, it was employed by neurosurgeons in cerebrovascular surgery and by general thoracic surgeons in carinal tumor resection. Indications for CPB were extended and modified year after year. It has facilitated not only the surgical management by surgeons of lesions that cannot be managed safely and effectively by conventional techniques, or conventional techniques carry significant risks to the patient, but also the preservation of the viability of multiple organ procurement, the practice of isolated limb perfusion for the treatment of malignancies of the extremities, and emergent cardiopulmonary resuscitation. Owing to the complications arising from CPB and profound hypothermic circulatory arrest, such as postoperative bleeding, coagulopathy, and neurologic deficits, efforts have been made to avoid these common hazards. Thus, innovative techniques including extracorporeal membrane oxygenation, percutaneous cardiopulmonary support, venovenous bypass, normothermic CPB, and minimally invasive approaches have emerged and played an important role as alternatives of standard CPB in decreasing morbidity and mortality and improving survival.

Catheter Ablation for the Treatment of Electrical Storm in Patients With Implantable Cardioverter-Defibrillators

Background— Electrical storm (ES) caused by recurrent episodes of ventricular tachycardia (VT) can cause sudden death in patients with implantable cardioverter-defibrillators and adversely affects prognosis in survivors. Catheter ablation has been proposed for treating ES, but its long-term effect in a large population has never been verified.

Methods and Results— Ninety-five consecutive patients with coronary artery disease (72 patients), idiopathic dilated cardiomyopathy (10 patients), and arrhythmogenic right ventricular dysplasia/cardiomyopathy (13 patients) undergoing catheter ablation for drug-refractory ES were prospectively evaluated. Short-term efficacy was defined by a complete protocol of programmed electric stimulation and by in-hospital outcome; long-term analysis addressed ES recurrence, cardiac mortality, and VT recurrence. Pleomorphic/nontolerated VTs required electroanatomic and noncontact mapping in 48 and 22 patients, respectively, and percutaneous cardiopulmonary support in 10 patients. An epicardial approach was used in 10 patients. After 1 to 3 procedures, induction of any clinical VT(s) by programmed electrical stimulation was prevented in 85 patients (89%). ES was acutely suppressed in all patients; a minimum period of 7 days with stable rhythm was required before hospital discharge. At a median follow-up of 22 months (range, 1 to 43 months), 87 patients (92%) were free of ES and 63 patients (66%) were free of VT recurrence. Eight of 10 patients with persistent inducibility of clinical VT(s) had ES recurrence; 4 of them died suddenly despite appropriate implantable cardioverter-defibrillator intervention. All together, 11 of 95 patients (12%) died of cardiac-related reasons. In the group of patients presenting with all clinical VTs acutely abolished, no ES recurrence was documented, and cardiac mortality was significantly lower compared with the group of patients showing ≥1 clinical VT still inducible after catheter ablation.

Conclusions— Advanced strategies of catheter ablation applied to a large population of patients are effective in the short-term treatment of ES. By preventing ES recurrence, catheter ablation may play a protective role over the long term and, together with long-term pharmacological therapy, may favorably affect cardiac mortality.

Hybrid therapies for ventricular arrhythmias

In recent years several trials demonstrated the efficacy of implantable cardioverter-defibrillation (ICD) therapy in reducing cardiac and total mortality in patients affected by rapid ventricular tachycardia (VT) and/or ventricular fibrillation. Nevertheless, ICD do not prevent arrhythmia recurrences, thus being a palliative and not a curative treatment modality. The tolerance to ICD therapy varies greatly, and within individuals, this leading to a nonuniform acceptance of this form of therapy. The very frequent occurrence of VT, defined as an arrhythmic storm, may be a life threatening condition. The majority of ICD patients is under antiarrhythmic drug therapy, to reduce episodes of VT or to make antitachycardia pacing more effective by slowing the tachycardia rate. Drug therapy, however, may cause additional problems, and does not represent the optimal solution. The prevention of VT and/or ventricular fibrillation episodes and excessive ICD therapy, remains a worthwhile goal. Radiofrequency catheter ablation (RFCA) is a curative approach, and can be expected to reduce the frequency of recurrent VT episodes in the majority of patients. The combination of these treatment modalities (ICD and RFCA) is often described as hybrid therapy, implying that the two treatments act providing some form of synergism. In experienced centers, RFCA is now performed, regardless of whether the VT rate is rapid and/or is hemodynamically unstable. Newer mapping and ablation techniques are now available, enhancing the acute success rate of the procedure. In this review the most recent application of VT catheter ablation and the use of advanced mapping and ablation techniques will be discussed.

Critical time window for intra-arrest cooling with cold saline flush in a dog model of cardiopulmonary resuscitation

BACKGROUND

Mild hypothermia improves outcome when induced after cardiac arrest in humans. Recent studies in both dogs and mice suggest that induction of mild hypothermia during cardiopulmonary resuscitation (CPR) greatly enhances its efficacy. In this study, we evaluate the time window for the beneficial effect of intra-arrest cooling in the setting of prolonged CPR in a clinically relevant large-animal model.

METHODS AND RESULTS

Seventeen dogs had ventricular fibrillation cardiac arrest no flow of 3 minutes, followed by 7 minutes of CPR basic life support and 50 minutes of advanced life support. In the early hypothermia group (n=9), mild hypothermia (34 degrees C) was induced with an intravenous fluid bolus flush and venovenous blood shunt cooling after 10 minutes of ventricular fibrillation. In the delayed hypothermia group (n=8), hypothermia was induced at ventricular fibrillation 20 minutes. After 60 minutes of ventricular fibrillation, restoration of spontaneous circulation was achieved with cardiopulmonary bypass for 4 hours, and intensive care was given for 96 hours. In the early hypothermia group, 7 of 9 dogs survived to 96 hours, 5 with good neurological outcome. In contrast, 7 of 8 dogs in the delayed hypothermia group died within 37 hours with multiple organ failure (P=0.012).

CONCLUSIONS

Early application of mild hypothermia with cold saline during prolonged CPR enables intact survival. Delay in the induction of mild hypothermia in this setting markedly reduces its efficacy. Our data suggest that if mild hypothermia is used during CPR, it should be applied as early as possible.

Factors for Weaning From a Percutaneous Cardiopulmonary Support System (PCPS) in Patients With Severe Cardiac Failure A Comparative Study in Weaned and Nonweaned Patients

The percutaneous cardiopulmonary support system (PCPS) has been widely accepted for the treatment of patients with severe cardiac failure. This system, which uses Seldinger's method through a percutaneous approach, enables rapid application in emergency situations. However, the indication for deployment and discontinuation of PCPS has not yet been established. We evaluated the results of PCPS use for the treatment of patients with severe cardiac failure and investigated factors that would predict successful weaning from PCPS. A total of 32 patients (23 men and 9 women) who had PCPS for the treatment of severe cardiac failure between January 1997 and October 2004 were retrospectively reviewed. The mean age of the patients was 57 +/- 17 years (range, 14 to 78 years). PCPS was necessary for severe cardiac failure after cardiac surgery in 15 patients, pulmonary infarction in 4, acute myocardial infarction in 3, acute myocarditis in 3, and other causes in 7. The mean duration of PCPS support in all 32 patients was 134 +/- 117 hours (range, 8 to 532). Twelve patients (38%) could be weaned from PCPS (group A), while the remaining 20 patients (62%) could not (group B). The incidence of cardiac arrest prior to PCPS use (n = 10, 31%) was significantly (P < 0.05) lower in group A (1/12, 8%) than in group B (9/20, 45%). There were significant differences in the APACHE II scores, urine output, serum lactate levels, and epinephrine and dopamine dose received from PCPS induction to 72 hours after PCPS use between the 2 groups (P < 0.05). Multivariate logistic regression analysis showed that an episode of cardiac arrest prior to PCPS induction was the only significant predictor for the unsuitability for discontinuation of PCPS. This retrospective study showed the limitation of PCPS therapy for patients with an episode of cardiac arrest who did not show improvement in their APACHE II score, urine output, serum lactate levels, and catecholamine dose received within 72 hours after PCPS induction. These results may help formulate criteria for indication and discontinuation of PCPS for patients with severe cardiac failure.