Hidden mortality rate associated with extracorporeal membrane oxygenation

Primary neonatal and pediatric ECMO transport: First experience in Spain

INTRODUCTION

The organization of primary Extracorporeal membrane oxygenation (ECMO) transport is highly variable.

METHODS

To present the experience of the first mobile pediatric ECMO program in Spain, we designed a prospective descriptive study of all primary neonatal and pediatric (0-16 years) ECMO transports carried out over 10 years. The main variables recorded include demographic information, patient background, clinical data, ECMO indications, adverse events, and main outcomes.

RESULTS

39 primary ECMO transports were carried out with a 66.7% survival to hospital discharge. The median age was 1.24 months[IQR: 0.09-96]. Cannulation was mostly peripheral venoarterial (33/39). The mean response time from the call from the sending center to the departure of the ECMO team was 4 h[2.2-8]. The median inotropic score at the time of cannulation was 70[17.2-206.5], with a median oxygenation index of 40.5[29-65]. In 10% of the cases, ECMO-CPR was performed. Adverse events occurred in 56.4%, mostly related to the means of transport (40% overall). On arrival at the ECMO center, 44% of the patients underwent interventions. The median PICU stay was 20.5 days[11-32]. 5 patients developed neurological sequels. Statistically significant differences between survivors and deceased patients were not found.

CONCLUSIONS

A good survival rate, with a low prevalence of serious adverse events, suggests a clear benefit of primary ECMO transport when conventional therapeutic measures are exhausted and the patient is too unstable to undergo conventional transport. A nationwide primary ECMO-transport program must therefore be offered to all patients regardless of their location.

Patient Safety during ECMO Transportation: Single Center Experience and Literature Review

Background

Extracorporeal membrane oxygenation (ECMO) has been proven to support in lifesaving rescue therapy. The best outcomes can be achieved in high-volume ECMO centers with dedicated emergency transport teams.

Aim

The aim of this study was to analyze the safety of ECMO support during medical transfer on the basis of our experience developed on innovation cooperation and review of literature.

Methods

A retrospective analysis of our experience of all ECMO-supported patients transferred from regional hospital of the referential ECMO center between 2015 and 2020 was carried out. Special attention was paid to transportation-related mortality and morbidity. Moreover, a systematic review of the Medline, Embase, Cochrane, and Google Scholar databases was performed. It included the original papers published before the end of 2019.

Results

Twelve (5 women and 7 men) critically ill ECMO-supported patients with the median age of 33 years (2-63 years) were transferred to our ECMO center. In 92% (n = 11) of the cases venovenous and in 1 case, venoarterial supports were applied. The median transfer length was 45 km (5-200). There was no mortality during transfer and no serious adverse events occurred. Of note, the first ECMO-supported transfer had been proceeded by high-fidelity simulations. For our systematic review, 68 articles were found and 22 of them satisfied the search criteria. A total number of 2647 transfers were reported, mainly primary (90%) and as ground transportations (91.6%). A rate of adverse events ranged from 1% through 20% but notably only major complications were mentioned. The 4 deaths occurred during transport (mortality 0.15%).

Conclusions

Our experiences and literature review showed that transportation for ECMO patients done by experienced staff was associated with low mortality rate but life-threatening adverse events might occur. Translational simulation is an excellent probing technique to improve transportation safety.

Clinical Characteristics and Outcomes for Neonates, Infants, and Children Referred to a Regional Pediatric Intensive Care Transport Service for Extracorporeal Membrane Oxygenation

OBJECTIVES

To describe the clinical characteristics and outcomes of referrals for extracorporeal membrane oxygenation to a regional pediatric intensive care transport service, and identify clinical features at initial referral that predict the eventual need for extracorporeal membrane oxygenation.

DESIGN

Retrospective analysis of prospectively collected data.

SETTING

Specialist pediatric intensive care transport service based at a large U.K. extracorporeal membrane oxygenation center.

PATIENTS

All referrals made for potential extracorporeal membrane oxygenation transport between January 2014 and July 2017.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Demographic and clinical data at the time of referral, referral outcome, and 90-day mortality status were extracted. Univariate and multivariate analyses were used to identify clinical features at initial referral in neonates that predicted the need for extracorporeal membrane oxygenation. Of 253 extracorporeal membrane oxygenation referrals, 203 were included: 64 of 203 received extracorporeal membrane oxygenation (31.5%), 18 were accepted for extracorporeal membrane oxygenation but died before extracorporeal membrane oxygenation could be provided (8.8%), and 121 did not receive extracorporeal membrane oxygenation (59.6%). The transport team mobilized in 136 of 203 referrals (66.9%); conventional transport to an extracorporeal membrane oxygenation center was successful in 127 of 136 (93.4%), while nine of 136 were too unstable to transport. The 90-day mortality for the cohort was 17.7% (36/203). In logistic regression analysis, the odds ratio of requiring extracorporeal membrane oxygenation for diaphragmatic hernia was 12.0 (95% CI, 2.8-52.1) compared to meconium aspiration syndrome. Oxygenation index and Vasoactive-Inotropic Score were independent predictors of the need for extracorporeal membrane oxygenation in neonates.

CONCLUSIONS

In this large cohort of neonatal and pediatric extracorporeal membrane oxygenation referrals to a pediatric intensive care transport service, a considerable portion of extracorporeal membrane oxygenation referrals (59.6%) continued on conventional management; however, 8.8% of the referrals died before extracorporeal membrane oxygenation could be provided. Earlier referral for extracorporeal membrane oxygenation; targeted referral triage using primary diagnosis, oxygenation index, and Vasoactive-Inotropic Score; and access to mobile extracorporeal membrane oxygenation services and faster mobilization of transport teams are important factors that could improve outcomes.

International Survey on Extracorporeal Membrane Oxygenation Transport

Extracorporeal membrane oxygenation (ECMO) is a lifesaving therapy for severe respiratory and circulatory failure. It is best performed in high-volume centers to optimize resource utilization and outcomes. Regionalization of ECMO might require the implementation of therapy before and during transfer to the high-volume center. The aim of this international survey was to describe the manner in which interhospital ECMO transport care is organized at experienced centers. Fifteen mobile ECMO centers from nine countries participated in this survey. Seven (47%) of them operated under the "Hub-and-Spoke" model. Transport team composition varies from three to nine members, with at least one ECMO specialist (i.e., nurse or perfusionist) participating in all centers, although intensivists and surgeons were present in 69% and 50% of the teams, respectively. All centers responded that the final decision to initiate ECMO is multidisciplinary and made bedside at the referring hospital. Most centers (75%) have a quality control system; all teams practice simulation and water drills. Considering the variability in ECMO transport teams among experienced centers, continuous education, training and quality control within each organization itself are necessary to avoid adverse events and maintain a low mortality rate. A specific international ECMO Transport platform to share data, benchmark outcomes, promote standardization, and provide quality control is required.

Interhospital Transport on Extracorporeal Membrane Oxygenation of Neonates-Perspective for the Future

In recent years the number of extracorporeal membrane oxygenation (ECMO) cases in neonates has been relatively constant. Future expansion lays in new indications for treatment. Regionalization to high-volume ECMO centers allows for optimal utilization of resources, reduction in costs, morbidity, and mortality. Mobile ECMO services available "24-7" are needed to provide effective logistics and reliable infrastructure for patient safety. ECMO transports are usually high-risk and complex. To reduce complications during ECMO transport communication using time-out, checklists, and ECMO A-B-C are paramount in any size mobile program. Team members' education, clinical training, and experience are important. For continuing education, regular wet-lab training, and simulation practices in teams increase performance and confidence. In the future the artificial placenta for the extremely premature infant (23-28 gestational weeks) will be introduced. This will enforce the development and adaptation of ECMO devices and materials for increased biocompatibility to manage the high-risk prem-ECMO (28-34 weeks) patients. These methods will likely first be introduced at a few high-volume neonatal ECMO centers. The ECMO team brings bedside competence for assessment, cannulation, and commencement of therapy, followed by a safe transport to an experienced ECMO center. How transport algorithms for the artificial placentae will affect mobile ECMO is unclear. ECMO transport services in the newborn should firstly be an out-reach service led and provided by ELSO member centers that continuously report transport data to an expansion of the ELSO Registry to include transport quality follow-up and research. For future development and improvement follow-up and sharing of data are important.

[Interhospital transport of patients with ARDS]

In patients with severely compromised gas exchange, interhospital transportation is frequently necessary due to the need to provide access to specialized care. Risks are inherent during transport, so the anticipated benefits of transportation must be weighed against the possible negative outcome during the transport. The use of specialized teams during transportation can help to reduce adverse events. Diligent planning of the transportation, monitoring and medical staff during transport can decrease adverse events and reduce risks. This article defines the group of patients that may benefit from referral. This article discusses the risks associated with the transportation of patients with severely impaired gas exchange and the risks related to different means of transportation. The decisions required before transportation are described as well as the practical approach starting at the transferring hospital until arrival at the admitting hospital.

HandS ECMO: Preliminary Experience With "Hub and Spoke" Model in Neonates With Meconium Aspiration Syndrome

We aim to evaluate clinical outcomes of emergent extracorporeal membrane oxygenation (ECMO) implantation in newborns with life-threatening meconium aspiration syndrome (MAS) in peripheral hospitals with Hub and Spoke (HandS) setting. We retrospectively reviewed all neonates presenting with MAS, with no other comorbidities, treated with HandS ECMO, in peripheral hospitals. Team activation time (TAT) was described as the time from first alerting call to ECMO support initiation. From May 2014 to December 2016, 4 patients met our inclusion criteria. In addition, 2 cases occurred on the same day, requiring a second simultaneous HandS ECMO team activation. All patients were younger than 8 days of life (1, 1, 4, and 7), with a mean BSA 0.21 ± 0.03m² , and TAT of 203, 265, 320, and 340 min. One patient presented ventricular fibrillation after priming administration. Veno-arterial ECMO was established in all patients after uneventful surgical neck vessels cannulation (right carotid artery and jugular vein). Mean time from skin incision to ECMO initiation was 19 ± 1.4 min. Mean length of ECMO support was 2.75 ± 1.3 days. All patients were weaned off support without complications. At a mean follow up of 20.5 ± 7.8 months, all patients are alive, with no medications, normal somatic growth, and neuropsychological development. MAS is a life-threatening condition that can be successfully managed with ECMO support. A highly trained multidisciplinary HandS ECMO team is crucial for the successful management of these severely ill newborns in peripheral hospitals.

Extracorporeal Membrane Oxygenation with Veno-Venous Bypass and Apneic Oxygenation for Treatment of Severe Neonatal Respiratory Failure

Seven newborn infants with life-threatening respiratory failure were treated with veno-venous (V-V) extracorporeal lung support and apneic oxygenation after maximal ventilatory and pharmacological treatment failed. Diagnosis were meconium aspiration syndrome in 3 cases, respiratory distress syndrome in 2, sepsis in 1, congenital diaphragmatic hernia in 1. Before ECMO 6 infants received tolazoline, 4 surfactant, 3 high frequency ventilation, 1 prostaglandin E, 1 epoprostenol, 2 nitric oxide. Newborns were highly hypoxemic at admission and all but one underwent rescue cannulation. V-V bypass was performed with a single lumen single cannula and tidal flow was generated by an alternating clamp using a non-occlusive roller pump. The mean duration of bypass was 162, 4±162.3 hours and infants were extubated 94.5±74.8 hours after decannulation. Five newborns survived and two died. Growth and neurologic development of the older children is normal. The extracorporeal lung support with V-V bypass associated with apneic oxygenation was effective in reversing severe neonatal respiratory failure unresponsive to maximal ventilatory and pharmacological support. An early referral, prior to meeting ECMO criteria, is important in order to avoid hypoxic complications preceding ECMO.

The Influence of Lung Injury due to Mechanical Ventilation on the Initiation of Ecmo

Before the entry criteria for extracorporeal membrane oxygenation (ECMO) are met, newborns may require aggressive mechanical ventilation which may result in lung injury. The question arises whether the presence of a pneumothorax in these infants plays a role in the prognosis. Of the 21 newborns transferred to our hospital for ECMO, 8 were treated with ECMO. 9 of the 21 newborns developed a pneumothorax with conventional ventilation and 6 of these 9 newborns subsequently required ECMO. Infants who developed a pneumothorax but did not meet ECMO criteria and remained in the oxygenation index (01) range between 25 and 40 for more than 2 days had a poorer prognosis. If adequate oxygenation cannot be attained with acceptable mechanical ventilation and a more aggressive ventilation results in a pneumothorax, ECMO should be considered even if the oxygenation index is below 40.

Transport While on Extracorporeal Membrane Oxygenation Support

Extracorporeal membrane oxygenation (ECMO) support for severe acute respiratory failure has been increasing. Evidence suggests that higher volume centers have better outcomes, leading to a need for specialized ECMO transport teams. The inherent nature of the prehospital environment adds an additional layer of complexity; however, the experience of multiple centers has demonstrated that cannulating and transporting a patient on ECMO can be performed safely. The purpose of this review article is to discuss the state of knowledge with respect to ECMO transport with special emphasis given to how to actually undertake such complex transports.

Inter-hospital transports on extracorporeal membrane oxygenation in different health-care systems

The feasibility and the recognition of the possibility to transport patients on extracorporeal membrane oxygenation (ECMO) aroused in the 1970s. The number of transporting facilities worldwide was less than 20 in the beginning of the second Millennium. In 2009 the H1N1 pandemic and a publication showing survival benefit for adult patients transported to a hospital with ECMO resource increased both awareness and interest for ECMO treatment. The number of transport organizations increased rapidly. As of today, the number of transport organizations increases world-wide, though some centers where ECMO is an established treatment report decreasing numbers of transports. Since the introduction of the more user-friendly equipment (ECMO-2 era) increasing numbers of low-volume ECMO centers perform these complex treatments. This overview is based on the current literature, personal experience in the field, and information from the authors' network on the organization of ECMO transport systems in different settings of health care around the globe. Registry data since the entry into ECMO-2 shows that the number of ECMO treatments matter. The more treatments performed at a given center the better the patient outcome, and the better these resources are spent for the population served. A Hub-and-Spoke model for national or regional organization for respiratory ECMO (rECMO) should be advocated where central high-volume ECMO center (Hub) serves a population of 10 to 15 million. Peripheral units (Spokes) play an important part in emergency cannulations keeping the patient on ECMO support till a mobile ECMO team retrieves the patient. This ECMO team is preferably organized from the Hub and brings competencies for assessment and decision to initiate ECMO treatment bedside at any hospital, for cannulation, and a safe transport to any destination. To conclude, most ECMO transport organizations are reflections of the health care paradigm within which they act. Most transport organizations are established by the staff within who recognize the need. The legal space seems open in most countries; anyone may set up a transport organization anywhere. Quality follow-up varies. Some keep track of adverse events and report whereas most transport entities do not seem to prioritize this. There is no international body for ECMO transports. Such would be the key for definitions, support, networking, and a registry that successively would increase knowledge concerning adverse events, morbidity and mortality.

Transportation of patients on extracorporeal membrane oxygenation: a tertiary medical center experience and systematic review of the literature

Background

Utilization of extracorporeal membrane oxygenation (ECMO) has increased worldwide, but its use remains restricted to severely ill patients, and few referral centers are properly structured to offer this support. Inter-hospital transfer of patients on ECMO support can be life-threatening. In this study, we report a single-center experience and a systematic review of the available published data on complications and mortality associated with ECMO transportation.

Methods

We reported single-center data regarding complications and mortality associated with the transportation of patients on ECMO support. Additionally, we searched multiple databases for case series, observational studies, and randomized controlled trials regarding mortality of patients transferred on ECMO support. Results were analyzed independently for pediatric (under 12 years old) and adult populations. We pooled mortality rates using a random-effects model. Complications and transportation data were also described.

Results

A total of 38 manuscripts, including our series, were included in the final analysis, totaling 1481 patients transported on ECMO support. A total of 951 patients survived to hospital discharge. The pooled survival rates for adult and pediatric patients were 62% (95% CI 57–68) and 68% (95% CI 60–75), respectively. Two deaths occurred during patient transportation. No other complication resulting in adverse outcome was reported.

Conclusion

Using the available pooled data, we found that patient transfer to a referral institution while on ECMO support seems to be safe and adds no significant risk of mortality to ECMO patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s13613-016-0232-7) contains supplementary material, which is available to authorized users.

Adverse Events during Inter-Hospital Transports on Extracorporeal Membrane Oxygenation

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) may be a lifesaving rescue therapy in refractory, severe respiratory, and/or circulatory failure. To provide the best cost efficiency to the population served and patient outcome, ECMO therapy should be provided by specialized high volume ECMO centers. This requires dedicated transport teams to organize and perform these complex transports. Concerning adverse events and complications during these transfers, only a minimal amount of data has been published.

METHODS

To shed light on this matter, all medical transport records from transports on ECMO between January 2010 and June 2016 were analyzed. The data was classified in constituent groups and categorized to risk groups.

RESULTS

During the study period, 536 transports on ECMO were performed. The transport records could be identified in 514 of these cases (95.9%). In 163 (31.7%) transports 206 adverse events occurred. In 34 transports two or more adverse events passed on the same trip. No deaths occurred during transport. Sixty-five percent (134) of the complications were Patient related; the most prominent was loss of tidal volume with or without fluid flooding of the lung (n = 57, 43%). Lack of control of equipment was the most common Staff related flaw. Causes due to Equipment/technical (n = 30) could be traced to 14.6% of the events. Vehicle/transportation related complications were reported from 26 transfers, a sub-group in which 50% of the reports concerned malfunction of Ambulance utility/electrical, or Wrong ambulance size at hospital or airport.

CONCLUSIONS

If transporting on ECMO high-risk or sudden threat-of-life situations are inevitable and have to be dealt with immediately, sometimes within seconds. A well-trained staff and an experienced high-volume organization are recommended. Key words: extra corporeal membrane oxygenation; ECMO, transport; adverse event; complication.

Outcome Comparison in Children Undergoing Extracorporeal Life Support Initiated at a Local Hospital by a Mobile Cardiorespiratory Assistance Unit or at a Referral Center

PURPOSE

To compare characteristics and outcome in children undergoing extracorporeal life support initiated in an extracorporeal life support center or at the patient's bedside in a local hospital, by means of a mobile cardiorespiratory assistance unit.

METHODS

A retrospective study in a single PICU during 6 years. Extracorporeal life support was started either in our center (control group) or in the local hospital (mobile cardiorespiratory assistance unit group). The data collected were demographics, markers of patient's preextracorporeal life support condition, and outcome.

RESULTS

One hundred twenty-six children underwent extracorporeal life support, 105 in the control group and 21 in the mobile cardiorespiratory assistance unit group. There was no difference between groups in terms of age, weight, or Pediatric Risk of Mortality II score. There was a significant difference in organ failure etiology between groups, with more respiratory cases in the mobile cardiorespiratory assistance unit group (76.2%) and more cardiac surgery cases in the control group (60%; p < 0.001). The duration of extracorporeal life support was longer in the mobile cardiorespiratory assistance unit group than in the control group (10 [1-36] vs 5 [0-33] d; p = 0.003). PICU length of stay and mortality (60% vs 47.6%; p = 0.294) were not significantly different between the two groups. To allow comparison of a more homogenous population, a subgroup analysis was performed including only respiratory failure patients from the two groups (R-control group [n = 22] and R-mobile cardiorespiratory assistance unit group [n = 16]). PICU length of stay was 17 (3-64) days in the R-control group and 23 (1-45) days in the R-mobile cardiorespiratory assistance unit group (p = 0.564), and PICU mortality rate was 54.5% in the R-control group and 43.8% in the R-mobile cardiorespiratory assistance unit group (p = 0.511). There was no difference between the R-groups for age, weight, Pediatric Risk of Mortality II score, and markers of kidney or liver dysfunction, and lactate blood levels.

CONCLUSION

Extracorporeal life support can be safely initiated at children's bedside in the local hospital and then transported to the specialized referral center. Our results support the validity of an interregional organization of mobile cardiorespiratory assistance unit teams.

Successful 2,000-Kilometer International Transfer of an Infant Receiving Extracorporeal Membrane Oxygenation for Severe Respiratory Failure

There is minimal reported experience with long-range retrieval of pediatric patients receiving extracorporeal membrane oxygenation (ECMO) support. We report the case of a 10-month old boy with necrotizing staphylococcal pneumonia complicated by a bronchopleural fistula, who was successfully retrieved and transported while receiving ECMO to our unit in Sydney, Australia, from a referring hospital 2,000 kilometers away in the Pacific Islands. He was successfully weaned from ECMO to receive single-lung ventilation after 13 days, and he underwent surgical repair of his bronchopleural fistula through a thoracotomy 3 days after decannulation. He has made a full recovery.

Transportation of Critically Ill Patients on Extracorporeal Membrane Oxygenation

Extracorporeal membrane oxygenation (ECMO) may be a life-saving procedure for patients with severe reversible pulmonary or cardiac failure or for patients in need for a bridge to transplantation. ECMO is provided by specialized centers, but patients in need of ECMO are frequently taken care of at other centers. Conventional transports to an ECMO center can be hazardous and deaths have been described. For this reason, many ECMO centers have developed transport programs with mobile ECMO. After request, the mobile team including all necessary equipment to initiate ECMO is sent to the referring hospital, where the patient is cannulated and ECMO commenced. The patient is then transported on ECMO to the ECMO facility by road, helicopter, or fixed-wing aircraft depending on distance, weather conditions, etc. Eight publications have reported series of more than 50 transports on ECMO of which the largest included over 700. Together, these papers report on more than 1400 patient transports on ECMO. Two deaths during transport have occurred. A number of other adverse events are described, but without effect on patient outcome. Survival of patients transported on ECMO is equivalent to that of non-transported ECMO patients. It is concluded that long-, short-distance interhospital transports on ECMO can be performed safely. The staff should be experienced and highly competent in intensive care, ECMO cannulation, ECMO treatment, intensive care transport, and air transport medicine.

Capabilities of a mobile extracorporeal membrane oxygenation service for severe respiratory failure delivered by intensive care specialists

We conducted a single-centre observational study of retrievals for severe respiratory failure over 12 months. Our intensivist-delivered retrieval service has mobile extracorporeal membrane oxygenation capabilities. Sixty patients were analysed: 34 (57%) were female and the mean (SD) age was 44.1 (13.6) years. The mean (SD) PaO2 /FI O2 ratio at referral was 10.2 (4.1) kPa and median (IQR [range]) Murray score was 3.25 (3.0-3.5 [1.5-4.0]). Forty-eight patients (80%) required veno-venous extracorporeal membrane oxygenation at the referring centre. There were no cannulation or extracorporeal membrane oxygenation-related complications. The median (IQR [range]) retrieval distance was 47.2 (14.9-77.0 [2.3-342.0]) miles. There were no major adverse events during retrieval. Thirty-seven patients (77%) who received extracorporeal membrane oxygenation survived to discharge from the intensive care unit and 36 patients (75%) were alive after six months. Senior intensivist-initiated and delivered mobile extracorporeal membrane oxygenation is safe and associated with a high incidence of survival.

Retrieval of critically ill adults using extracorporeal membrane oxygenation: an Australian experience

PURPOSE

A retrieval program was developed in New South Wales (NSW), Australia to provide extracorporeal membrane oxygenation support (ECMO) for the safe transport of adults with severe, acute respiratory or cardiac failure. We describe the development and results of this program and the impact of the 2009 H1N1 epidemic on this service.

METHODS

An observational study of all patients who were retrieved on ECMO support in NSW, from March 1, 2007 to June 1, 2010, was carried out.

RESULTS

Forty adult patients were retrieved on ECMO support (median age 34 years). The indications for retrieval were respiratory in 38 patients (of whom 16 were confirmed or suspected H1N1 cases) and cardiac in 2 patients. Two other patients died after referral but before ECMO support could be established. Patients were transported by road (n = 26, 65%), medical retrieval jet (n = 10, 25%) and helicopter (n = 4, 10%). The median retrieval distance was 250 km (range 12-1,960 km). Thirty-four patients (85%) survived to hospital discharge. Survival for respiratory indications was 87% (33/38 patients) and 50% (1/2 patients) for cardiac indications. There were no deaths or major morbidity associated with these retrievals.

CONCLUSIONS

Patients with very severe respiratory failure, which was considered to preclude conventional ventilation for safe transfer to tertiary centres, were managed by an ECMO referral and retrieval program in NSW and had a high rate of survival. This program also enhanced the capacity of the state to respond to a surge in demand for ECMO support due to the H1N1 epidemic, although the role of ECMO in respiratory failure is not yet well defined.

Single-institution experience with interhospital extracorporeal membrane oxygenation transport: A descriptive study

OBJECTIVE

Patients with refractory cardiopulmonary failure may benefit from extracorporeal membrane oxygenation, but extracorporeal membrane oxygenation is not available in all medical centers. We report our institution's nearly 20-yr experience with interhospital extracorporeal membrane oxygenation transport.

DESIGN

Retrospective review.

SETTING

Quaternary care children's hospital.

PATIENTS

All patients undergoing interhospital extracorporeal membrane oxygenation transport by the Arkansas Children's Hospital extracorporeal membrane oxygenation team.

INTERVENTIONS

Data (age, weight, diagnosis, extracorporeal membrane oxygenation course, hospital course, mode of transport, and outcome) were obtained and compared with the most recent Extracorporeal Life Support Organization Registry report.

RESULTS

Interhospital extracorporeal membrane oxygenation transport was provided to 112 patients from 1990 to 2008. Eight were transferred between outside facilities (TAXI group); 104 were transported to our hospital (RETURN group). Transport was by helicopter (75%), ground (12.5%), and fixed wing (12.5%). No patient died during transport. Indications for extracorporeal membrane oxygenation in RETURN patients were cardiac failure in 46% (48 of 104), neonatal respiratory failure in 34% (35 of 104), and other respiratory failure in 20% (21 of 104). Overall survival from extracorporeal membrane oxygenation for the RETURN group was 71% (74 of 104); overall survival to discharge was 58% (61 of 104). Patients with cardiac failure had a 46% (22 of 48) rate of survival to discharge. Neonates with respiratory failure had an 80% (28 of 35) rate of survival to discharge. Other patients with respiratory failure had a 62% (13 of 21) rate of survival to discharge. None of these survival rates were statistically different from survival rates for in-house extracorporeal membrane oxygenation patients or for survival rates reported in the international Extracorporeal Life Support Organization Registry (p > .1 for all comparisons).

CONCLUSIONS

Outcomes of patients transported by an experienced extracorporeal membrane oxygenation team to a busy extracorporeal membrane oxygenation center are very comparable to outcomes of nontransported extracorporeal membrane oxygenation patients as reported in the Extracorporeal Life Support Organization registry. As has been previously reported, interhospital extracorporeal membrane oxygenation transport is feasible and can be accomplished safely. Other experienced extracorporeal membrane oxygenation centers may want to consider developing interhospital extracorporeal membrane oxygenation transport capabilities to better serve patients in different geographic regions.

A 20-year experience on neonatal extracorporeal membrane oxygenation in a referral center

OBJECTIVE

Advances in treatment of neonatal respiratory failure are responsible for a decline in the number of newborns treated with extracorporeal membrane oxygenation (ECMO). The aim of this study are to determine demographic changes, focusing on time of referral, diagnosis, and respiratory parameters in neonates put on ECMO.

DESIGN

Retrospective review.

SETTING

Tertiary ECMO center.

PATIENTS

A total of 321 neonates were treated with ECMO from January 1987 to December 2006.

RESULTS

Overall number of patients increased with every 5-year period, whereby congenital diaphragmatic hernia (CDH) was the most common diagnosis (53%), followed by meconium aspiration syndrome (MAS) (21%), sepsis and/or pneumonia (13%), and others such as persistent pulmonary hypertension of the newborn (PPHN), respiratory distress syndrome (RDS), or hypoplasia of the lung (13%). Worsening severity of illness as measured by ECMO duration and days on ventilator has to be stated for all diagnoses. Nevertheless, survival rate remained stable; both overall and diagnosis-specific mortality rates did not change significantly. Of all children, 67% survived to discharge or transfer, while best rates were seen for MAS (94%), followed by sepsis and/or pneumonia (69%), CDH (62%), and other diagnoses (43%). Concerning survival rate, no difference between inborn and outborn children occurred. However, between early- and late-referred children, a referral to the ECMO center during the first 24 h of life was associated with a significantly higher rate of survival (77% versus 54%, p = 0.0004), predominantly seen for CDH (67% versus 35%, p = 0.02).

CONCLUSION

We strongly recommend timely transfer to an ECMO center in patients with CDH who are at risk of circulatory failure.

Comparison of the Sensormedics 3100A and Bronchotron transporter in a neonatal piglet ARDS model

The Sensormedics 3100A (Cardinal Health, Dublin, OH) (HFOV) and the Bronchotron (Percussionaire, Sandpoint, ID) (HFPV) are high-frequency ventilation devices used to support neonatal respiratory failure; however, a comparison of the devices, with respect to gas exchange at similar ventilator settings, has not been previously studied. Thus, we compared the ability of HFOV to that of HFPV to provide oxygenation and ventilation during acute lung injury in a newborn animal model. Using a saline lung lavage model, 12 neonatal piglets were randomized to initial support with either the HFOV or HFPV with settings adjusted to achieve PaCO2 of 45-60 mmHg. After stabilization, ventilator settings and arterial blood gases were serially recorded for 30 min. Animals were then crossed over to the alternative device set to deliver the same V(t), MAP, and F for an additional 30 min with the same parameters recorded. We found that the DeltaP needed to generate adequate V(t) on HFPV (35 +/- 7 cm H2O) trended higher versus HFOV (31 +/- 7 cm H2O P = 0.09) when the devices were matched for V(t), F, and MAP. No significant differences in ventilation (PaCO(2) = 50 +/- 10.7 mmHg vs. 46 +/- 10 mmHg, P = 0.22) or oxygenation (PaO2 = 150 +/- 76 mmHg vs. 149 +/- 107 mmHg, P = 0.57) between the devices were found. We conclude that HFPV ventilates and oxygenates as well as HFOV at equivalent ventilator settings. HFPV may require larger DeltaP's to generate equivalent V(t).

Meconium aspiration syndrome remains a significant problem in the NICU: outcomes and treatment patterns in term neonates admitted for intensive care during a ten-year period

OBJECTIVE

The purpose of this study was to evaluate the demographic and treatment characteristics of neonates (>or=37 weeks' estimated gestational age) who were admitted to a neonatal intensive care unit (NICU) for a diagnosis of meconium aspiration syndrome (MAS) during the years 1997 to 2007. The goals in studying this group of neonates were to better estimate the magnitude of abnormal outcomes and to determine the proportion of these infants exposed to specific therapeutic interventions.

STUDY DESIGN

Retrospective review of an administrative de-identified data set.

RESULT

A total of 415,772 neonates formed the starting data set and 162,075 (39%) were >or=37 weeks. Of the 162,075 term neonates, 7518 (1.8% of all neonates and 4.6% of term NICU admissions) had an admission diagnosis of MAS. In the 7518 neonates, the following outcomes were observed: 6124 (81.5%) were discharged home; 679 (9%) were acutely transferred to a higher level of intensive care; 416 (5.5%) were transferred to another clinical service within the hospital; 178 (2.4%) were transferred to another NICU for convalescent care and 88 (1.2%) died. There were 33 (0.4%) who did not have data on outcome at discharge. During the period between 2002 and 2005, acute transfer rates decreased (12.4 to 9%) and the reported rate for death remained relatively constant between 0.9 and 1.5%. There were 107 (1.4%) neonates who were treated (n=61) with, or transferred, for extracorporeal membrane oxygenation (ECMO) (n=46). Three of the sixty-one neonates (4.9%) who were treated with ECMO died.

CONCLUSION

Term neonates who are admitted with a diagnosis of MAS continue to represent a high-risk population with significant morbidity, and they often require intensive therapies.

A 22-year experience in global transport extracorporeal membrane oxygenation

BACKGROUND/PURPOSE

Transport extracorporeal membrane oxygenation (ECMO) is currently available at 12 centers. We report a 22-year experience from the only facility providing global transport ECMO. Indications for transport ECMO include lack of ECMO services, inability to transport conventionally, inability to wean from cardiopulmonary bypass, extracorporeal cardiopulmonary resuscitation, and need to move a patient on ECMO for specialized services such as organ transplantation.

METHODS

Retrospective database review of children undergoing inhouse and transport ECMO from 1985 to 2007.

RESULTS

Sixty-eight children underwent transport ECMO. Fifty-six were transported on ECMO into our facility. The remaining 12 were moved between 2 outside locations. Ground vehicles and fixed-wing aircraft were used. Distance transported was 8 to 7500 miles (13-12070 km), mean 1380 miles (2220 km). There were 116 inhouse ECMO runs. No child died during transport. Survival to discharge after transport ECMO was 65% (44/68) and, for inhouse ECMO, was 70% (81/116).

CONCLUSIONS

Transport ECMO is feasible and effective, with survival rates comparable to inhouse ECMO. We have used transport ECMO to help children at non-ECMO centers with pulmonary failure who have not improved with inhaled nitric oxide and high-frequency ventilation. We have also transported a child after extracorporeal cardiopulmonary resuscitation, which may represent an emerging indication for transport ECMO. Transport ECMO often is the only option for children too unstable for conventional transport or those already on ECMO and requiring a specialized service at another facility, such as organ transplantation.

The epidemiology of respiratory failure in neonates born at an estimated gestational age of 34 weeks or more

OBJECTIVE

To prospectively evaluate the primary causes for the use of mechanical ventilation in near-term neonates and to determine the rates of death, chronic lung disease, and neurological complications in these infants.

STUDY DESIGN

We collected data on 1011 neonates who were > or =34 weeks' estimated gestational age; intubated within 72 hours of birth; and expected to require ventilation for more than 6 hours.

RESULTS

The study population had a mean estimated gestational age of 37+/-2 weeks; had a mean birth weight of 2.9+/-0.6 kg; and were predominantly male (62%), white (69%), and delivered by cesarean section (55%). Respiratory distress syndrome (n=437) was the most common pulmonary illness. Chronic lung disease was diagnosed in 109 (11%); neurological complications were reported in 86 (9%); and 51 (5%) patients died.

CONCLUSIONS

Neonates > or =34 weeks who require mechanical ventilation represent a high-risk population who have significant morbidity and mortality.

A review of 100 patients transported on extracorporeal life support

Between May 1990 and January 1999, 100 patients (68 adult, 32 pediatric) with severe respiratory or cardiac instability were successfully transported to the University of Michigan Medical Center on extracorporeal life support. Diagnoses included adult respiratory distress syndrome (n = 78), cardiac failure (n = 7), sepsis (n = 7), asthma (n = 5), respiratory distress syndrome (of newborn) (n = 2), and airway compromise (n = 1). Of the patients, 53 were supported with venovenous bypass and 47 with venoarterial bypass. Patients were transported by ground ambulance (n = 80), helicopter (n = 15), or fixed-wing aircraft (n = 5). The median transport distance was 44 miles (range 2-790 miles), and the median transport time was 5 hours and 30 minutes (range: 1 h 33 min to 16 h 6 min). Sixty-six patients (66%) survived to discharge. One death occurred during cannulation, and two patients died before cannulation began. Complications that occurred during transport included 10 cases of electrical failure, 3 cases of circuit tubing leakage, and 1 case each of circuit rupture, membrane lung thrombosis, and membrane lung leakage. None of the complications occurring during transport had an adverse effect on outcome. We conclude that the long distance transport of patients on extracorporeal life support can be safely accomplished and is an effective option for the unstable patient with severe respiratory or cardiac failure.

Referral and transportation for neonatal extracorporeal membrane oxygenation

Data from 32 patients who were transported for neonatal extracorporeal membrane oxygenation (ECMO) over a 66-month period were reviewed. One ground ambulance transport had to be postponed because of poor weather conditions; the patient died. One patient was excluded for ECMO on arrival at the ECMO centre. Of the remaining 30 infants, 20 (67%) required ECMO treatment, of which four (20%) died. All 10 (33%) patients who were treated with conventional therapy survived. During transportation all children remained stable in terms of oxygenation. Early referral and transportation by an experienced and well-equipped transport team allows safe transport of these critically ill neonates.

A 16-year neonatal/pediatric extracorporeal membrane oxygenation transport experience

OBJECTIVE

To characterize the population and survival of neonatal and pediatric patients transported by Wilford Hall Medical Center (WHMC) on extracorporeal membrane oxygenation (ECMO) since 1985.

STUDY DESIGN

A retrospective chart, literature, and database review of pediatric and neonatal patients transported on ECMO by the WHMC ECMO transport team. In addition, a subpopulation analysis was performed comparing neonates with meconium aspiration syndrome (MAS) placed on ECMO at WHMC with those infants with MAS transported on ECMO. Characteristics of interest for this comparison included disease severity before ECMO, age at initiation of ECMO, survival, ECMO-related complications, and duration of ECMO support.

RESULTS

Forty-two patients transported on ECMO were identified: 23 neonatal respiratory cases (survival 57%), 7 pediatric respiratory cases (survival 71%), 4 cardiac cases (survival 50%), and 8 extra-institutional ECMO transports (survival 63%). In the MAS subpopulation, there was significantly greater survival in the in-house group--97% (31/32)--than in the ECMO transport group--75% (9/12); there were no other significant differences between these groups. Overall, no ECMO-related complications leading to patient demise could be identified in the ECMO transport group.

CONCLUSIONS

ECMO transport, although demonstrating acceptable survival, is a risk-laden modality that should not replace early referral to an ECMO center.

Persistent pulmonary hypertension of the newborn. Rational therapy based on pathophysiology

Persistent pulmonary hypertension of the newborn is a common disorder among near-term gestation newborns. Persistent pulmonary hypertension of the newborn is characterized by hypoxemia that is frequently refractory to conventional management. This article describes the pathophysiologic basis of the disorder and the current therapy that is based on this knowledge.

Detrimental effects of standard medical therapy in congenital diaphragmatic hernia

OBJECTIVE

To evaluate the impact of a nonstandard ventilation strategy on survival in congenital diaphragmatic hernia (CDH).

BACKGROUND

Despite recent advances, including nitric oxide, CDH remains an unsolved problem with a mortality rate of 35% to 50%. Hyperventilation and alkalization remain common therapies.

METHODS

In 1992, the authors prospectively abandoned hyperventilation and alkalization. Patients are lightly sedated and ventilated with the lowest pressure providing adequate chest movement, and the rate is set to patient comfort. Nitric oxide and extracorporeal membrane oxygenation (ECMO) are reserved for life-threatening instability. Surgical repair is delayed 1 to 5 days. Sixty consecutive patients are compared with 29 previous patients treated with hyperventilation and alkalization, 13 before and 16 after the availability of ECMO.

RESULTS

Overall, 47 of 60 patients (78%) in study era 3 survived compared with 2 of 13 (15%) in the hyperventilation era and 7 of 16 (44%) in the hyperventilation/ECMO era (p < 0.0001). The disease severity and the incidence of associated anomalies did not differ between groups. To compare management strategies, patients who had treatment withheld because of lethal associated conditions were then removed from analysis. Peak inspiratory pressure and arterial pH were lower (p < 0.0001) and Paco2 was higher (p < 0.05) in era 3 than in the previous eras. The rate of pneumothorax (1.9%) decreased (p < 0.0001). In era 3, survival was 47 of 53 (89%) treated patients, and 23 of 25 inborn patients with isolated CDH survived (92%).

CONCLUSIONS

Nonstandard ventilatory support of patients with CDH has led to significantly improved survival rates. This study sets a survival benchmark and strongly suggests the negative effects of hyperventilation and alkalization.

Safety of withdrawing inhaled nitric oxide therapy in persistent pulmonary hypertension of the newborn

OBJECTIVE

Because of case reports describing hypoxemia on withdrawal of inhaled nitric oxide (I-NO), we prospectively examined this safety issue in newborns with persistent pulmonary hypertension who were classified as treatment successes or failures during a course of I-NO therapy.

METHODS

Randomized, placebo-controlled, double-masked, dose-response clinical trial at 25 tertiary centers from April 1994 to June 1996. Change in oxygenation and outcome (death and/or extracorporeal membrane oxygenation) during or immediately after withdrawing I-NO were the principal endpoints. Patients (n = 155) were term infants, <3 days old at study entry with echocardiographic evidence of persistent pulmonary hypertension of the newborn. Exclusion criteria included previous surfactant treatment, high-frequency ventilation, or lung hypoplasia. Withdrawal from treatment gas (0, 5, 20, or 80 ppm) started once treatment success or failure criteria were met. Withdrawal of treatment gas occurred at 20% decrements at <4 hours between steps.

RESULTS

The patient profile was similar for placebo and I-NO groups. Treatment started at an oxygenation index (OI) of 25 +/- 10 (mean +/- SD) at 26 +/- 18 hours after birth. For infants classified as treatment successes (mean duration of therapy = 88 hours, OI <10), decreases in the arterial partial pressure of oxygen (PaO(2)) were observed only at the final step of withdrawal. On cessation from 1, 4, and 16 ppm, patients receiving I-NO demonstrated a dose-related reduction in PaO(2) (-11 +/- 23, -28 +/- 24, and -50 +/- 48 mm Hg, respectively). For infants classified as treatment failures (mean duration of therapy = 10 hours), no change in OI occurred for the placebo group (-13 +/- 36%, OI of 31 +/- 11 after the withdrawal process); however a 42 +/- 101% increase in OI to 46 +/- 21 occurred for the pooled nitric oxide doses. One death was possibly related to withdrawal of I-NO.

CONCLUSION

For infants classified as treatment successes, a dose response between the I-NO dose and decrease in PaO(2) after discontinuing I-NO was found. A reduction in I-NO to 1 ppm before discontinuation of the drug seems to minimize the decrease in PaO(2) seen. For infants failing treatment, discontinuation of I-NO could pose a life-threatening reduction in oxygenation should extracorporeal membrane oxygenation not be readily available or I-NO cannot be continued on transport.

A population-based study of congenital diaphragmatic hernia: impact of associated anomalies and preoperative blood gases on survival

BACKGROUND/PURPOSE

Although neonatal care has improved over the past 20 years, mortality rate with congenital diaphragmatic hernia (CDH) remains 50% to 60%, possibly reflecting differences in management or selection biases. The authors determined the incidence, outcome, effect of coexisting anomalies, and prognostic indicators for neonates with CDH in a single inborn population older than 13 years.

METHODS

Forty-three neonates with CDH, those symptomatic within the first 6 hours of life, were identified using a validated neonatal database and diagnosis coding data from medical records among 180,643 live inborn neonates delivered at Parkland Memorial Hospital between 1983 and 1995. Charts were reviewed for prenatal history, demographic variables, presence of coexisting malformations, preoperative arterial blood gases, surgical findings, and outcome. Survival to hospital discharge was the primary outcome variable.

RESULTS

The incidence of CDH was 1 in 4,200 live births; overall survival rate was 51%. Thirty-two (74%) neonates underwent surgical repair, often at less than 8 hours of life; postoperative mortality rate was 31%. Eighteen (42%) had coexisting major anomalies or chromosomal abnormalities. Eighty percent of neonates with isolated CDH survived, whereas 89% with CDH and associated defects died. Nonsurvivors had lower birth weights and Apgar scores, were more acidotic, and had more severe respiratory compromise. When best preoperative pH was > or = 7.25 or PaCO2 < or = 50 mm Hg, 80% of neonates survived.

CONCLUSION

In this inborn population-based review of neonatal CDH between 1983 and 1995, the best predictors of survival were the presence or absence of other anomalies and the best preoperative PaCO2 and pH.

Congenital diaphragmatic hernia--a tale of two cities: the Toronto experience

PURPOSE

The optimal therapy for congenital diaphragmatic hernia (CDH) is evolving. This study analyzes the results of treatment of CDH in a large tertiary care pediatric center using conventional and high-frequency oscillatory ventilation (HFOV) without extracorporeal membrane oxygenation (ECMO) contrasting these with a parallel study from a similar large urban center using conventional ventilation with ECMO.

METHODS

Between 1981 and 1994, 223 consecutive neonates who had CDH diagnosed in the first 12 hours of life were referred for treatment before repair. Conventional ventilation was used with conversion to HFOV for refractory hypoxemia or hypercapnia, and a predicted near 100% mortality rate. ECMO was used in only three patients, all of whom died. A retrospective database was collected. Thirty-one clinical variables were tested for their association with the outcome. Common ventilatory and oxygenation indices were tested for their prognostic capability.

RESULTS

Apgar scores, birth weight, right-sided defects, pneumothorax, total ventilatory time, and the use of high frequency oscillatory ventilation were the only variables associated with outcome. A modified ventilatory index and postductal A-aDo2 were strong prognostic indicators. From 1981 to 1984 surgery was performed on an emergency basis. Since 1985 surgery was deferred until stabilization had been achieved. This resulted in a shift in the mortality from postoperative to preoperative with no change in total survival. HFOV did not alter the overall survival. Results of autopsies performed (70%) showed significant pulmonary hypoplasia and barotrauma as the primary causes of death. The survival was 54.7%.

CONCLUSION

Conventional ventilation with HFOV produced equal survival to conventional ventilation with ECMO in two comparable series. Pulmonary hypoplasia was the principle cause of death. This continued high mortality at both centers suggests that new therapies are required to improve outcomes.

A cost-effectiveness analysis of neonatal ECMO using existing evidence

A cost-effectiveness analysis is part of the U.K. ECMO Trial. In preparation for this analysis, existing evidence on the costs and effectiveness of neonatal ECMO was evaluated. ECMO appears to be more costly but may be more or less effective than conventional treatment. No case can be made for introducing ECMO before trial results are available.

The effect of on-site extracorporeal membrane oxygenation on the therapy choice and outcomes of neonates with persistent pulmonary hypertension

The effect of on-site extracorporeal membrane oxygenation (OS-ECMO) and selection criteria on the utilization rate of this technology is unknown. We retrospectively studied 55 neonates who were admitted to Arkansas Children's Hospital from 1985 to 1993. We compared the ECMO utilization, mortality, and morbidity rates for outborn neonates with moderate and severe persistent pulmonary hypertension (PPHN) before and after the establishment of an ECMO program with guidelines for its use at our institution. The rate of ECMO use was three times higher and the mortality rate was 13 times lower in the period after OS-ECMO compared with the period when ECMO was available only at other institutions. No differences were observed in the morbidity rates between the two periods. Physician decisions to initiate ECMO involved more than guidelines, since 37% of the increased ECMO use was not associated with use of the guidelines. Possible reasons for noncompliance with the guidelines are discussed. Neonates who had received medical therapy only and who had an oxygenation index > or = 30 and < 40 had no mortality. Our findings suggest that the need for ECMO in this group of neonates is low.

Extracorporeal membrane oxygenation. Will this therapy continue to be as efficacious in the future?

The efficacy of ECMO has been discussed. If only a dichotomous live/die outcome is used as a measure of utility, ECMO is efficacious for infants with a greater than 20% mortality rate. Using a Bayesian approach and neonatal follow-up data, one concludes that ECMO, as used at present, is effective. Future measures of efficacy will vary depending on utility measures used, the populations studied, and the relative efficacy of alternative therapies.

Mobile extracorporeal membrane oxygenation

Transport of critically ill neonates in need of extracorporeal membrane oxygenation can be risky. Their extreme cardiorespiratory instability may delay or even preclude conventional transport to an extracorporeal membrane oxygenation center. We report the use of a UH-1 helicopter specially adapted for mobile extracorporeal membrane oxygenation support to transport a critically ill neonate.

A population-based study of congenital diaphragmatic hernia

From 1983 through 1987, in a California population of 718,208 births, 237 infants were born with a congenital diaphragmatic hernia (CDH), a birth prevalence of 3.30 per 10,000 total births (live births and stillbirths). We proposed that the various types of this defect, characterized by their different pathogeneses, would be reflected in differences in their descriptive epidemiologies. We evaluated various demographic, maternal, and infant characteristics for three major types of defects, the Morgagni hernia, the pars sternalis hernia, and the posterolateral hernia, categorizing the latter type into isolated defect (N = 129), multiple congenital anomalies including nonchromosomal syndromes (N = 86), trisomies (N = 10), and chromosomal anomalies other than trisomies (N = 2). For the posterolateral hernia, we present the distribution of associated anomalies (43%) and specifically of midline defects (19%). Although the number of cases for the Morgagni hernia (N = 5) and the pars sternalis hernia (N = 5) were small, comparisons with the posterolateral hernia suggested lower sex ratios, of borderline significance for the pars sternalis hernia (P < 0.09), and higher mean maternal ages for both groups. Within the posterolateral type, we found a significantly higher male to female ratio (M/F = 1.58) only for the isolated subgroup compared to the population (P < 0.03), and a borderline significant rural/urban difference in prevalences (2.12 vs. 1.45 per 10,000) (P < 0.06). Additionally, the distribution of monthly prevalence rates adjusted for gestational age suggested opposite seasonal trends between the isolated and the other posterolateral hernias; within this latter subgroup the difference between the highest monthly rate (1.68) and the lowest (0.96) was of borderline significance (P < 0.09). Our results suggest the need to consider the respective types and subgroups of CDH separately in epidemiologic studies.