Right Atrial Cannulation via Thoracotomy for Emergent Extracorporeal Membrane Oxygenation in Pediatric Patients with Prior Sternotomy

Extracorporeal membrane oxygenation (ECMO) is the most common mechanical circulatory support strategy used to treat pediatric patients presenting with low cardiac output or cardiogenic shock. While transthoracic central cannulation is feasible and mostly utilized for early postoperative support, peripheral cannulation is preferred as a primary strategy in the late postoperative period. Redo-sternotomy and venous cannulation are difficult to achieve in patients with occluded peripheral veins or complex venous anatomy like Glenn circulation. In pediatric patients with multiple prior sternotomy and catheterization procedures, vascular access for cannulation is frequently limited. Peripheral cannulation for venoarterial ECMO (VA-ECMO) may be challenging or even impossible. In our case series, four pediatric patients with prior sternotomy underwent right atrial cannulation emergently in patients to secure venous drainage for ECMO support. Extracorporeal membrane oxygenation support could be established rapidly with adequate venous drainage in all cases. We conclude that right atrial cannulation via right thoracotomy can be a useful technique for venous cannulation in cases with prior sternotomy and is particularly useful in cases with Glenn circulation.

Venoarterial extracorporeal membrane oxygenation support for neonatal and pediatric refractory septic shock

Objective:

To report our institutional experience of veno-arterial extracorporeal membrane oxygenation (VA ECMO) in children with refractory septic shock.

Materials and Methods:

We retrospectively reviewed our ECMO database to identify patients who received VA ECMO for septic shock from January 2004 to June 2013 at our Pediatric Intensive Care Unit in Armand-Trousseau Hospital. We included all neonates and children up to the age of 18 years who received VA ECMO for septic shock. For each patient, we collected the pre-ECMO inotrope score, clinical circulatory and ventilatory parameters, infecting organism, ECMO duration and complications, and length of hospital stay.

Main Results:

The study included 14 neonates and 8 older children (the pediatric population, with a mean age of 30 months, range: 1–113 months). Survival was 64% among newborns and 50% among pediatric patients. Multiorgan failure or severity scores did not show any correlation with mortality (Pediatric Logistic Organ Dysfunction score, P = 0.94; the score for neonatal acute physiology-perinatal extension II, P = 0.34). In the pediatric population, the inotrope score was higher in the survivor group (127.5 vs. 332.5, P = 0.07). Blood samples taken shortly before cannulation showed that pH (P = 0.27), lactate level (P = 0.33), PaO2/FiO2 ratio (P = 0.49), or oxygenation index (P = 0.35) showed no correlation to success or failure of ECMO.

Conclusion:

ECMO can be safely used to resuscitate and support children with refractory septic shock. We recommend that patients with oliguria whose lactate level has not decreased within 6 h of starting maximum drug therapy be transferred to an ECMO referral center.

Postoperative management of heart failure in pediatric patients

Low cardiac output syndrome (LCOS) is a well-described entity occurring in 25-65% of pediatric patients undergoing open-heart surgery. With judicious intensive care management of LCOS, most patients have an uncomplicated postoperative course, and within 24 h after cardiopulmonary bypass, the cardiac function returns back to baseline. Some patients have severe forms of LCOS not responsive to medical management alone, requiring temporary mechanical circulatory support to prevent end-organ injury and to decrease myocardial stress and oxygen demand. Occasionally, cardiac function does not recover and heart transplantation is necessary. Long-term mechanical circulatory support devices are used as a bridge to transplantation because of limited availability of donor hearts. Experience in usage of continuous flow ventricular assist devices in the pediatric population is increasing.

Extracorporeal membrane oxygenation for neonatal and pediatric respiratory failure: an evidence-based review of the past decade (2002-2012)

OBJECTIVE

To provide a comprehensive evidence-based review of extracorporeal membrane oxygenation for neonatal and pediatric respiratory failure.

DATA SOURCE

A thorough computerized bibliographic search of the clinical literature regarding the use of extracorporeal membrane oxygenation in the neonatal and pediatric populations.

STUDY SELECTION

Clinical trials published between January 1, 2002, and October 1, 2012, including "extracorporeal membrane oxygenation" or "ECMO" and limited to studies involving humans aged 0-18 years. Trials focused on extracorporeal membrane oxygenation for cardiac indications were excluded from this study, unless the study was evaluating ancillary therapies in conjunction with extracorporeal membrane oxygenation.

DATA EXTRACTION

Studies were evaluated for inclusion based on reporting of patient outcomes and/or strategic considerations, such as cannulation strategies, timing of extracorporeal membrane oxygenation utilization, and ancillary therapies.

DATA SYNTHESIS

Pertinent data are summarized, and the available data are objectively classified based on the value of the study design from which the data are obtained.

CONCLUSIONS

Despite a large number of published extracorporeal membrane oxygenation studies, there remains a paucity of high-quality clinical trials. The available data support continued use of extracorporeal membrane oxygenation for respiratory failure refractory to conventional therapy for neonatal and pediatric patients without significant comorbidities. Further research is needed to better quantify the benefit of extracorporeal membrane oxygenation and the utility of many therapies commonly applied to extracorporeal membrane oxygenation patients.

Clinical management of the extracorporeal membrane oxygenation circuit

The clinical management of patients on extracorporeal membrane oxygenation should be standardized and follow clear guidelines or protocols. However, due to the diversity of cannulation strategies and the complex situations that extracorporeal membrane oxygenation is now used in, each extracorporeal membrane oxygenation program has developed its own clinical management strategies. These vary widely across the globe. Extracorporeal membrane oxygenation provides partial or complete support of ventilation and oxygenation, as well as univentricular or biventricular support of myocardial function, either individually or in combination. High-flow extracorporeal membrane oxygenation can also provide circulatory support in profound vasoplegic shock. Improvements in technology and greater understanding of disease pathophysiology, coupled to refinements in technology, which lessen the adverse interaction between the circuit and the patient, all contribute to fewer mechanical and patient complications on extracorporeal membrane oxygenation. Earlier and more appropriate use of extracorporeal membrane oxygenation has been associated with improved patient outcomes. These clinical management strategies are reviewed in this article, part of the Pediatric Cardiac Intensive Care Society/Extracorporeal Life Support Organization Joint Statement on Mechanical Circulatory Support.

[Particularities of ECMO in acute respiratory distress syndrome in pediatrics]

Les techniques de circulation extracorporelle sont utilisées en pédiatrie dans les syndromes de détresse respiratoire aiguë (SDRA) les plus graves depuis les années 1980. Les données du registre international de l’Extracorporeal Life Support Organization révèlent plus 5 000 enfants placés en extracorporeal membrane oxygenation (ECMO) en 2012 avec une augmentation du nombre de cas annuels depuis l’épidémie de 2009. La survie, de 56 %, est stable alors que le nombre d’enfants avec des comorbidités augmente grâce aux améliorations apportées au matériel. Bien que nous ne disposions pas d’études randomisées, ces résultats encouragent à proposer l’ECMO dans l’arsenal thérapeutique du SDRA de l’enfant. Si les techniques veinoveineuses doivent être privilégiées dans les affections respiratoires, l’ECMO veinoartérielle peut être nécessaire et reste d’une utilisation fréquente chez l’enfant (50 % des cas). En pédiatrie, les particularités techniques sont liées d’une part aux particularités physiologiques de l’enfant et d’autre part aux contraintes dues au matériel proposé selon les différentes catégories d’âge. L’ECMO est une technique de recours lourde qui nécessite une expertise à la fois technique et pédiatrique spécialisée en raison de ce terrain particulier.

Extracorporeal life support: an update of Rogers' Textbook of Pediatric Intensive Care

INTRODUCTION

The field of extracorporeal life support, which has focused predominantly on extracorporeal membrane oxygenation in the past, is undergoing rapid expansion following years of stagnation as newer devices and improved technology have become available. Additionally, new cannulae and cannulation techniques have allowed extracorporeal life support to be expanded to many groups who would have been excluded from support in the past.

REVIEW

This update will review the current state of the art since Rogers' Textbook of Pediatric Intensive Care (Fourth Edition) was published several years ago. The changing environment of extracorporeal support in terms of patient populations, technological advances, patient management, and outcome will be discussed.

CONCLUSIONS

Continued examination of the criteria and circumstances where extracorporeal life support is applied as well as outcomes which include morbidity, cost effectiveness, and quality of life are needed areas of continued research. Increasing collaborations between all centers performing extracorporeal life support throughout the world should remain a priority to further research and understanding of this complex field.

Mechanical assistance of the circulation during cardiogenic shock

PURPOSE OF REVIEW

Cardiogenic shock still has a grave prognosis. We present the recent advances in mechanical circulatory support (MCS) for the treatment of refractory cardiogenic shock.

RECENT FINDINGS

The contraindications for short-term MCS in rapid-onset cardiogenic shock are becoming fewer and the threshold for its application has been progressively lowered. Short-term MCS is increasingly used in refractory cardiac arrest and will be probably integrated as the last means in the advanced cardiopulmonary resuscitation algorithm (provided there is experienced team and technical support). Improved device technology has contributed to improved results of long-term MCS. Emergent application of long-term MCS in patients with critical cardiogenic shock after a long history of progressively deteriorating end-stage chronic heart failure should be interpreted as delayed application associated with increased mortality.

SUMMARY

Although MCS can be life saving in cardiogenic shock, the results are still suboptimal. Mortality is associated with the critical presupport state and the adverse events during MCS. Early initiation of support that meets the patient's requirements, potent support in the early phase, adverse event prevention, global combined management (surgical, interventional, medical), balanced support duration, bridging to further therapeutic modalities including heart transplantation or longer-term support, and advanced technology could offer improved results.

Translational Research in Pediatric Extracorporeal Life Support Systems and Cardiopulmonary Bypass Procedures: 2011 Update

Over the past 6 years at Penn State Hershey, we have established the pediatric cardiovascular research center with a multidisciplinary research team with the goal to improve the outcomes for children undergoing cardiac surgery with cardiopulmonary bypass (CPB) and extracorporeal life support (ECLS). Due to the variety of commercially available pediatric CPB and ECLS devices, both in vitro and in vivo translational research have been conducted to achieve the optimal choice for our patients. By now, every component being used in our clinical settings in Penn State Hershey has been selected based on the results of our translational research. The objective of this review is to summarize our translational research in Penn State Hershey Pediatric Cardiovascular Research Center and to share the latest results with all the interested centers.

Hemodynamic evaluation of arterial and venous cannulae performance in a simulated neonatal extracorporeal life support circuit

Objective: To construct an ideal extracorporeal life support (ECLS) circuit in terms of hemodynamic performance, each component of the circuit should be evaluated. Most cannulae manufacturers evaluate their products using water as the priming solution. We conducted this study to evaluate the different sizes of arterial and venous cannulae in a simulated neonatal ECLS circuit primed with human blood.

Methods: The simulated neonatal ECLS circuit was composed of a Capiox Baby RX05 oxygenator, a Rotaflow centrifugal pump and a heater & cooler unit. Three Medtronic Bio-Medicus arterial cannulae (8Fr, 10Fr, 12Fr) and three venous cannulae (10Fr, 12Fr, 14Fr) were tested in seven combinations (8A-10V, 8A-12V, 10A-10V, 10A-12V, 10A-14V, 12A-12V, 12A-14V). All the experiments were conducted using human blood at a hematocrit of 40% and at a constant temperature of 37°C. The “tip to tip” priming volume of the entire circuit was 135ml. The blood volume of the pseudo patient was 500ml.

Results: Flow rates increased linearly with increasing size in both venous and arterial cannulae at the same pump speeds. The increase in flow rate was greater when changing the arterial cannulae (next size larger) compared to changing the venous cannulae (next size larger). The pressure drops of the arterial cannula were correlated with the flow rates, regardless of the pseudo patient pressure and the venous cannula used simultaneously.

Conclusions: The results show the difference in flow ranges and pressure drops of seven combinations of arterial and venous cannulae. It also suggests that the arterial cannula, not the venous cannula, has greater impact on the flow rate when a centrifugal pump is used in a neonatal ECLS circuit. The results of this study have been translated to further advancing the clinical practice in our institution.

Current status of pediatric/neonatal extracorporeal life support: clinical outcomes, circuit evolution, and translational research

Extracorporeal life support (ECLS) offers lifesaving mechanical circulatory support for patients afflicted with respiratory and/or cardiac failure. Neonatal respiratory patients have higher survival rates compared to pediatric patients, while, for cardiac cases, pediatric patients are more likely to survive. The indications for ECLS have been expanded due to the improved technology and favorable outcomes. However, the rate of mortality and morbidity for ECLS patients remains significant. Mechanical complications still comprise a large percentage of ECLS complications, leaving definite room for improvement in ECLS circuit technology in the future. As a pre-clinical evaluating tool, translational research will provide more useful information for the selection of ECLS devices, encourage further development of ECLS technology, and, ultimately, benefit the patients.

Left ventricular hypertrophy in men with normal blood pressure: relation to exaggerated blood pressure response to exercise

OBJECTIVE

To determine whether normal, nonhypertensive subjects who have unusually large increases of systolic blood pressure with exercise have left ventricular hypertrophy (LVH).

DESIGN

Case-comparison using echocardiography as a criterion standard for measurement of left ventricular mass and the diagnosis of LVH.

SETTING

Population-based health fitness screening program and referral Veterans Affairs Hospital.

SUBJECTS

Thirty-nine men (average age, 44.6 +/- 8.5 years; range, 34 to 71 years) were studied, including 25 participants in a health fitness screening program and an additional 14 normal men with atypical chest pain. Twenty-two subjects with a systolic blood pressure during peak exercise of 210 mm Hg or greater were compared with 17 others with systolic pressure less than 210 mm Hg during exercise.

MEASUREMENTS AND MAIN RESULTS

Left ventricular hypertrophy (left ventricular mass index greater than 134 g/m2) was found in 14 of 22 men with a systolic blood pressure of 210 mm Hg or greater (present in 6.3% of normotensive healthy male volunteers in a health screening program) but in only 1 person with a lower exercise blood pressure. Left ventricular mass index was linearly correlated (r = 0.65, n = 39, P less than 0.001) with maximum exercise blood pressure. Whereas LVH was mild in about 50%, substantial LVH was present in the others. The presence of LVH was not related to superior physical conditioning and was accompanied by increased left atrial size suggesting impaired left ventricular filling.

CONCLUSIONS

Even in the absence of hypertension, exaggerated blood pressure responses during exercise testing suggest a probability of 0.64 (95% CI, 0.41 to 0.83) of LVH, a finding associated with the cardiac "end-organ" manifestations of hypertension.