Extracorporeal membrane oxygenation in the treatment of inhalation injuries

Extracorporeal life support in pediatric burn care: A systematic review

A systematic review of the role of extracorporeal life support (ECLS) in pediatric patients with burn and smoke inhalation injury was undertaken. A systematic search of the literature according to a specific combination of keywords to ascertain the effectiveness of this treatment strategy was conducted. A total of 14 articles out of 266 were considered suitable for the analysis in pediatric patients. The PICOS approach and PRISMA flow chart were followed for the purpose of this review. Despite the limited number of studies on the subject, ECMO in burn and smoke inhalation injury provides an additional level of support in pediatric patients leading to positive outcomes. V-V ECMO demonstrated the best overall survival of all configurations, with similar outcomes to non-burned patients. Prolonged mechanical ventilation prior to ECMO decreases survival and increases mortality by 12% with each additional day off ECMO. Good outcomes have been described for scald burns, dressing changes, and pre-ECMO cardiac arrest.

A Systematic Review and Meta-Analysis of Extracorporeal Membrane Oxygenation in Patients with Burns

BACKGROUND

Severely burned patients are at high risk for cardiopulmonary failure. Promising studies have stimulated interest in using extracorporeal membrane oxygenation as a potential therapy for burn patients with refractory cardiac and/or respiratory failure. However, the findings from previous studies vary.

METHODS

In this study, the authors conducted a systematic review and meta-analysis using standardized mortality ratios to elucidate the benefits associated with the use of extracorporeal membrane oxygenation in patients with burn and/or inhalation injuries. A literature search was performed, and clinical outcomes in the selected studies were compared.

RESULTS

The meta-analysis found that the observed mortality was significantly higher than the predicted mortality in patients receiving extracorporeal membrane oxygenation (standardized mortality ratio, 2.07; 95 percent CI, 1.04 to 4.14). However, the subgroup of burn patients with inhalation injuries had lower mortality rates compared to their predicted mortality rates (standardized mortality ratio, 0.95; 95 percent CI, 0.52 to 1.73). Other subgroup analyses reported no benefits from extracorporeal membrane oxygenation; however, these results were not statistically significant. Interestingly, the pooled standardized mortality ratio values decreased as the selected patients' revised Baux scores increased (R = -0.92), indicating that the potential benefits from the treatment increased as the severity of patients with burns increased.

CONCLUSIONS

The authors' meta-analysis revealed that burn patients receiving extracorporeal membrane oxygenation treatment were at a higher risk of death. However, select patients, including those with inhalation injuries and those with revised Baux scores over 90, would benefit from the treatment. The authors suggest that burn patients with inhalation injuries or with revised Baux scores exceeding 90 should be considered for the treatment and early transfer to an extracorporeal membrane oxygenation center.

Successful use of extracorporeal membrane oxygenation in acute respiratory distress syndrome following accidental chlorine gas inhalation at a swimming pool

While there is evidence to support the use of extracorporeal membrane oxygenation in acute respiratory distress syndrome due to a variety of causes, its use in chlorine gas-induced acute respiratory distress syndrome has not been described in the English medical literature. We present a young girl who had severe acute respiratory distress syndrome following exposure to chlorine gas during the disinfection process at a swimming pool. She failed conventional management and underwent venovenous extracorporeal membrane oxygenation. Despite multiple infections and a pneumothorax, she eventually recovered. Chlorine gas was the first agent of chemical warfare which caused a massive death toll during the First World War. Even today, the chemical is produced in large quantities and the threat of a large-scale leak is ever-present from industrial accidents or terrorist attacks. The criteria to assess and manage chlorine gas-induced acute respiratory distress syndrome are likely to be the same as for other causes of acute respiratory distress syndrome and extracorporeal membrane oxygenation can be used successfully.

Management of Pulmonary Failure after Burn Injury: From VDR to ECMO

This article highlights the challenges in managing pulmonary failure after burn injury. The authors review several different ventilator techniques, provide weaning parameters, and discuss complications.

Current concepts in the pathophysiology and treatment of inhalation injury

The opinions or assertions contained herein are the private views of the author, and are not to be construed as official or as reflecting the official views of the Department of the Army or Department of Defense. Smoke inhalation injury occurs in about 10% of patients admitted to burn centres, and increases the mortality of burn patients by up to 20% over predictions based on age and burn size alone. The primary lesion in smoke inhalation injury is localized to the small airways, with alveolar injury and pulmonary oedema exercising a less prominent role during the initial phases. Injury incites a cascade of events that include ventilation-perfusion mismatch, secondary lung injury, systemic inflammation, impaired immune function, and pneumonia. The most important recent developments in the treatment of inhalation injury have included improved methods of pulmonary care targeted at the pathophysiology of the injury, such as high-frequency percussive ventilation and gentle mechanical ventilation.

The impact of the National Institute for Health Research Health Technology Assessment programme, 2003-13: a multimethod evaluation

BACKGROUND

The National Institute for Health Research (NIHR) Health Technology Assessment (HTA) programme supports research tailored to the needs of NHS decision-makers, patients and clinicians. This study reviewed the impact of the programme, from 2003 to 2013, on health, clinical practice, health policy, the economy and academia. It also considered how HTA could maintain and increase its impact.

METHODS

Interviews (n = 20): senior stakeholders from academia, policy-making organisations and the HTA programme. Bibliometric analysis: citation analysis of publications arising from HTA programme-funded research. Researchfish survey: electronic survey of all HTA grant holders. Payback case studies (n = 12): in-depth case studies of HTA programme-funded research.

RESULTS

We make the following observations about the impact, and routes to impact, of the HTA programme: it has had an impact on patients, primarily through changes in guidelines, but also directly (e.g. changing clinical practice); it has had an impact on UK health policy, through providing high-quality scientific evidence - its close relationships with the National Institute for Health and Care Excellence (NICE) and the National Screening Committee (NSC) contributed to the observed impact on health policy, although in some instances other organisations may better facilitate impact; HTA research is used outside the UK by other HTA organisations and systematic reviewers - the programme has an impact on HTA practice internationally as a leader in HTA research methods and the funding of HTA research; the work of the programme is of high academic quality - the Health Technology Assessment journal ensures that the vast majority of HTA programme-funded research is published in full, while the HTA programme still encourages publication in other peer-reviewed journals; academics agree that the programme has played an important role in building and retaining HTA research capacity in the UK; the HTA programme has played a role in increasing the focus on effectiveness and cost-effectiveness in medicine - it has also contributed to increasingly positive attitudes towards HTA research both within the research community and the NHS; and the HTA focuses resources on research that is of value to patients and the UK NHS, which would not otherwise be funded (e.g. where there is no commercial incentive to undertake research). The programme should consider the following to maintain and increase its impact: providing targeted support for dissemination, focusing resources when important results are unlikely to be implemented by other stakeholders, particularly when findings challenge vested interests; maintaining close relationships with NICE and the NSC, but also considering other potential users of HTA research; maintaining flexibility and good relationships with researchers, giving particular consideration to the Technology Assessment Report (TAR) programme and the potential for learning between TAR centres; maintaining the academic quality of the work and the focus on NHS need; considering funding research on the short-term costs of the implementation of new health technologies; improving the monitoring and evaluation of whether or not patient and public involvement influences research; improve the transparency of the priority-setting process; and continuing to monitor the impact and value of the programme to inform its future scientific and administrative development.

Extracorporeal membrane oxygenation in burn and smoke inhalation injury

A systematic review and meta-analysis was conducted to assess the level of evidence for the use of extracorporeal membrane oxygenation (ECMO) in hypoxemic respiratory failure resulting from burn and smoke inhalation injury. We searched any article published before March 01, 2012. Available studies published in any language were included. Five authors rated each article and assessed the methodological quality of studies using the recommendation of the Oxford Centre for Evidence Based Medicine (OCEBM). Our search yielded 66 total citations but only 29 met the inclusion criteria of burn and/or smoke inhalation injury. There are no available systematic reviews/meta-analyses published that met our inclusion criteria. Only a small number of clinical trials, all with a limited number of patients, were available. The overall data suggests that there is no improvement in survival for burn patients suffering acute hypoxemic respiratory failure, with the use of ECMO. ECMO run times of less than 200 h correlate with higher survival compared to 200 h or more. Scald burns show a tendency of higher survival than flame burns. In conclusion, the presently available literature is based on insufficient patient numbers; the data obtained and level of evidence generated are limited. The role of ECMO in burn and smoke inhalation injury is therefore unclear. However, ECMO technology and expertise have improved over the last decades. Further research on ECMO in burn and smoke inhalation injury is warranted.

Extracorporeal membrane oxygenation as a lifesaving modality in the treatment of pediatric patients with burns and respiratory failure

PURPOSE

Several case series have described successful utilization of extracorporeal membrane oxygenation (ECMO) for the treatment of pediatric burn patients with respiratory failure. This study examines the Extracorporeal Life Support Organization registry experience in the treatment of these patients.

METHODS

The Extracorporeal Life Support Organization registry was queried from 1999 to 2008 for all patients not older than 18 years who suffered a burn-related injury.

RESULTS

Thirty-six patients met inclusion criteria. The mean age was 4.45 years, with an average weight of 20.9 kg. Survivors vs nonsurvivors had a shorter average time to ECMO (97 vs 126 hours, P = .890) and shorter average ECMO run times (193 vs 210 hours, P = .745). Seventeen patients underwent venovenous ECMO and 19 patients underwent venoarterial ECMO, with survival of 59% (n = 10) and 47% (n = 9), respectively (P = .493; odds ratio, 1.587; 95% confidence interval, 0.424-5.945). Overall survival was 53% (n = 19). Complications occurred in 28 patients (33 mechanical, 101 medical). The venoarterial group had 21 mechanical (n = 8) and 61 medical complications (n = 17), compared with the venovenous group with 12 mechanical (n = 8) and 40 medical complications (n = 11).

CONCLUSIONS

Extracorporeal membrane oxygenation can be a lifesaving modality for pediatric burn patients with respiratory failure. Survival is comparable to the reported survival of non-burn-related pulmonary failure pediatric patients requiring ECMO.

Lung injury from smoke inhalation

Significant morbidity and mortality from smoke inhalation occurs in victims of fire. Lung injury can be caused by chemical and thermal insults. A variety of noxious gases, irritants and asphyxiants are generated depending on the material burnt. Carbon monoxide is the predominant cause of death among fire victims. Treatment should be directed at reversing hypoxaemia as a result of asphyxia or carbon monoxide poisoning. There is no evidence that the routine use of corticosteroids or prophylactic antibiotics is beneficial. Through a better understanding of the pathophysiology of smoke-induced lung injury, the effects of exogenous surfactant, leukotriene inhibitors, antioxidants, nitric oxide synthase inhibitors and fibrinolytics suggest that these compounds may have a future therapeutic role in smoke-induced injury. Studies are needed to evaluate the safety and efficacy of these potential therapies before they are used clinically.

Expanded application of extracorporeal membrane oxygenation in a pediatric surgery practice

OBJECTIVE

To examine the breadth of application and resulting outcomes in a university-based extracorporeal membrane oxygenation (ECMO) program directed by pediatric surgeons.

SUMMARY BACKGROUND DATA

Several randomized control trials have supported the use of ECMO in neonates with respiratory failure. No comparable data exist for older children and young adults who may be afflicted with a variety of uncommon conditions. The indications for ECMO in these patients remain controversial.

METHODS

Patient data were recorded prospectively and reported to the Extracorporeal Life Support Organization. These data were analyzed by indications and outcomes on all patients treated since the inception of the program.

RESULTS

Two hundred sixteen patients were treated with 225 courses of ECMO. Neonates (188 [87%]) outnumbered 28 older patients (aged 6 weeks to 22 years). Overall, 174 patients survived (81%). Sixty-four of 65 (98.5%) neonates with meconium aspiration syndrome survived. ECMO support after heart (3), lung (2), heart-lung (1), and liver (1) transplant yielded a 57% survival to discharge. ECMO also resulted in survival of patients with uncommon conditions, including severe asthma (1), hydrocarbon aspiration (1/2), congestive heart failure due to a cerebral arteriovenous malformation (1), tracheal occlusion incurred during endoscopic stent manipulation (2), meningitis (1), and viral pneumonia (3/5).

CONCLUSIONS

ECMO can potentially eliminate mortality for meconium aspiration syndrome. Survival for other causes of respiratory failure in neonates and older children, while not as dramatic, still surpasses that anticipated with conventional therapy. Moreover, survival of transplant patients has been comparable to that achieved in other children.

Artificial lungs: a new inspiration

An estimated 16 million Americans are afflicted with some degree of chronic obstructive pulmonary disease (COPD), accounting for 100,000 deaths per year. The only current treatment for chronic irreversible pulmonary failure is lung transplantation. Since the widespread success of single and double lung transplantation in the early 1990s, demand for donor lungs has steadily outgrown the supply. Unlike dialysis, which functions as a bridge to renal transplantation, or a ventricular assist device (VAD), which serves as a bridge to cardiac transplantation, no suitable bridge to lung transplantation exists. The current methods for supporting patients with lung disease, however, are not adequate or efficient enough to act as a bridge to transplantation. Although occasionally successful as a bridge to transplant, ECMO requires multiple transfusions and is complex, labor-intensive, time-limited, costly, non-ambulatory and prone to infection. Intravenacaval devices, such as the intravascular oxygenator (IVOX) and the intravenous membrane oxygenator (IMO), are surface area limited and currently provide inadequate gas exchange to function as a bridge-to-recovery or transplant. A successful artificial lung could realize a substantial clinical impact as a bridge to lung transplantation, a support device immediately post-lung transplant, and as rescue and/or supplement to mechanical ventilation during the treatment of severe respiratory failure.

Extracorporeal membrane oxygenation for severe respiratory failure

The use of extracorporeal technology to accomplish gas exchange with or without cardiac support is based on the premise that "lung rest" facilitates repair and avoids the baso- or volutrauma of mechanical ventilator management. Extracorporeal membrane oxygenation (ECMO), a modified form of cardiopulmonary bypass, has been shown to decrease mortality of neonatal, pediatric and adult respiratory failure and is capable of total gas exchange. In neonates, over 20,638 patients have been treated with an overall survival of 77% in a population thought to have 78% mortality.

Application of extracorporeal membrane oxygenation in adult burn patients

Adult respiratory distress syndrome (ARDS) has been the major cause of mortality in burn injury. The authors reported the experience of using extracorporeal membrane oxygenation (ECMO) to treat adult burn patient with ARDS. Three patients with burn or electric injury, around 48.9% of body surface area over second-degree burns, developed ARDS after resuscitation. All had positive blood culture and depended on a ventilator more than 5 days before ECMO. Venovenous (VV) ECMO was started at the beginning of severe respiratory failure with an oxygen index of 61.6 +/- 15.5 cm H2O/mm Hg (> or =40 cm H2O/mm Hg), partial arterial oxygen tension to inspired oxygen fraction (Pa(O2)/Fi(O2)) of 46.1 +/- 7.0 mm Hg (< or =200 mm Hg), positive end expiratory pressure (PEEP) of 15.7 +/- 1.6 cm H2O (> or =10 cm H2O), alveolar-arterial difference in oxygen concentration (A-a D(O2)) of 618.9 +/- 19.3 mm Hg (> or =300 mm Hg), and lung compliance of 17.3 +/- 4.6 ml/cm H2O (< or =30 ml/cm H2O). The VV type had to be converted to the newly designed veno-venoarterial (V-VA) ECMO due to the myocardial dysfunction. Two of three patients survived. The duration of ECMO was 160.2 +/- 51.1 h. Two patients received debridement of escar during ECMO support and desmopressin infusion, and no increased bleeding or coagulopathy was found. The respiratory parameters were significantly improved after ECMO, especially in the survivors. ECMO is also suitable for ARDS in adult burn injury.