A systematic research review (SRR)

A systematic review of the literature (SRR)

A systematic review of the literature (SRR) summarizes the information gathered through a rigorous method of discovering, evaluating, and synthesizing studies to answer a specific clinical question. The collected data is then used to draw conclusions (Graulich 2002). SRR is used in evidence-based practice to eliminate bias caused by individual research. The purpose of this work is to conduct a comprehensive review of the use of extracorporeal membrane oxygenation (ECMO) in acute, large pulmonary embolisms (PE). The review looks at the benefits of ECMO as well as statistical data on patient survival rates. ECMO can be used alone or in conjunction with surgical intervention. This paper will describe the relevance of the research problem. In addition, it will critique the rigor of the study, and identify the level of evidence. It will also interrogate the clarity with which the study is presented. This paper will describe and summarize the findings. The conclusion will provide recommendations for current and future practice.

Relevance of Research

The cause of a pulmonary embolism is the blockage of the main artery of the lung. This may be caused by a blood clot that travels through the bloodstream. Pulmonary embolisms have many origins: they may be caused by a clot in the leg, air or fat emboli. Intravenous drug use also causes pulmonary embolism. This is a condition that carries a high mortality rate. It affects people of all ages and genders. Some of the symptoms associated with PE include; breathing difficulty, sudden chest pains, cyanosis, tachycardia, hypertension, low oxygen supply and even sudden death. According to Yusuff, Zochios, and Vuylsteke (2015), a massive PE is characterized by dysfunction of the right ventricle and systolic blood pressure less than 90 mmHg. There is recorded evidence that supports the fact that patients with hypertension or circulatory arrest have a 90-day mortality rate of 52% (2015). ECMO is a life-saving option in patients with massive pulmonary embolisms. When compared to other causes of cardiac arrest, patients who survived a massive PE presented a good neurological outcome. This is because it is the most reliable and quickest way to reduce ventricular failure, improve hemodynamics and restore oxygen to tissues (Lidén 2009). The authors compared the effectiveness of ECMO among patients suffering from thrombolysis, surgical embolectomy, and catheter embolectomy and studied the success of ECMO in acute, massive PE. In nursing, research has become extremely important over the years. The reason research is taking a more central role in nursing is because the treatment patients receive has a huge bearing on their well-being.

Research Rigor

The authors searched for quantitative studies that were based on cases published over the last 20 years, relating to the use of ECMO in the treatment of acute, massive pulmonary embolisms. There were no other SRRs on this subject performed according to their search. The databases MEDLINE and EMBASE were searched using key words that included: extracorporeal life support, extracorporeal membrane oxygenation, pulmonary embolism, massive pulmonary embolism and percutaneous cardiopulmonary support. The authors used the Boolean term AND in the search adding the terms acute, peripheral and fulminant. Results were limited to articles published in English. Between the years 1995 and 2014, a total of nineteen papers were used in the systematic research review. 78 adult patients were reviewed in the study, and all patients received ECMO alone, or ECMO was combined with other therapies. There was no demographic information or ethnicity of patients included in the research. The researchers organized the data collected on an Apple keynote spreadsheet and used descriptive statistics to describe the demographic and continuous data. Dichotomous variables were expressed as percentages. Statistical software was used to analyze the differences between dichotomous variables. The authors used logistical regression analysis when appropriate to test differences. A two-sided p-value of 0.05 was used to test for significance (2015). Two of the authors reviewed the articles and excluded studies on patients under the age of eighteen years old and decided on relevant articles using a flow diagram according to predesigned eligibility. The authors provided thirty-one references from scholarly sources at the end of the article. Based on the levels of evidence, this article is a secondary source and falls on the third level of the evidence pyramid as a systematic research review of quantitative studies. If though there are no randomized control trials or meta-analysis provided, this article summarizes the statistics collected and could be considered a meta-analysis.

Levels of Evidence

Based on research, systematic reviews are considered the best evidence when clinicians are searching for information. SRRs are either a summary of what is known or a summary of the research on an intervention. A meticulous process is used to isolate appropriate studies. This process is based on the criteria that have been developed by the researcher in advance. The results of studies are synthesized, but no statistics are calculated (Lidén 2009). Case studies along with case reports were used in this SRR which included "11 single-case reports and 8 case series. A total of 78 patients were described, with an average age of 49.5 years old. Thre case reports did not provide data on the duration of extracorporeal support," (Flamant 2005). No randomized control trials or meta-analyses were found in the authors' searches. As stated earlier in this paper, the article falls on the third level of the evidence pyramid as a systematic review providing quantitative results from case studies.

Clarity

In this SRR, detailed keywords were used for the search; specific databases were listed along with tables providing supporting data. This included: the number of patients from each study, age, number of days on ECMO, intensive care unit, the length of stay and survival rate. The study described the combination therapies used and survival rates. The article explains clearly that the authors reviewed case studies and explained the limitations. According to the authors, the case studies were susceptible to bias. Such bias was either in publication or in reporting meaning that only descriptive aggregation of data was possible; this was the main limitation of our review," (Shu-Chien 2007). No randomized control trials have been performed since it would be unethical to deny a patient a life-saving technique for the benefits of research. The article included a flow diagram to display the exclusion of articles and explained that data was included based on predetermined criteria. Finally, the authors clearly state the research received no grant money or funding for the research and reports no conflict of interest in their study.

Findings

Among the 78 patients studied, the overall survival rate was 70.1% or 55 patients. According to the article, ECMO is a lifesaving option, combined with thrombolysis, surgical embolectomy, catheter embolectomy or, on its own, for massive PE is linked to positive outcomes. In another study conducted in 2009 in Japan, 193 patients with massive PE receiving ECMO alone or in combination with therapeutic interventions had a survival rate of 73%. The studies showed that patients already in cardiac arrest that had ECMO instituted had a higher risk of death (Shu-Chien 2007). 100% of the sixteen patients that received ECMO alone survived. A common practice found throughout the authors' research that an algorithm was developed for right ventricular failure. An inferior vena cava filter was placed after weaning from ECMO. In addition, it was found that ECMO was associated with good outcomes among patients suffering massive PE.

Conclusion

Effective life-saving treatment in conjunction with therapeutic interventions is necessary for patients with acute massive PE. The authors of the study provided data on ECMO along with treatments for PE such as surgical embolectomy, thrombolysis, and catheter embolectomy, duration of intensive care stay, duration of extracorporeal support, and extracorporeal support for cardiopulmonary resuscitation. Moreover, quantitative results were provided in tables and summarized. Mortality rates associated with the different treatments were described. Overall ECMO is beneficial for patients with massive PE. Further research is necessary in order to provide more recent data on the most current case studies, and there is no information provided regarding those patients not selected for ECMO with massive PE. When conducting randomized control trials of ECMO use in PE. It is important to overcome difficulties that are present in the classic drug trials. Also, management of therapy must be reproducible before undertaking a meaningful prospective trial," (Flamant 2005). Health care is ever dynamic, thus we must stay current on evidence-based practices. Research has become tremendously important over the years, and the objective of evidence-based practice is to provide high quality care to patients.

References

Shu-Chien Huang; En-Ting Wu; Nai-Hsin Chi; Shuenn-Nan Chiu; Pei-Ming Huang; Yih-Sharng Chen; Yung-Chie Lee; Wen-Je Ko. Perioperative extracorporeal membrane oxygenation support for critical pediatric airway surgery. European Journal of Pediatrics.Nov2007, Vol. 166 Issue 11, p1129-1133.

Lidén, H.; Wiklund, L.; Haraldsson, Å.; Berglin, E.; Hultman, J.; Dellgren, G. Temporary circulatory support with extra corporeal membrane oxygenation in adults with refractory cardiogenic shock. Scandinavian Cardiovascular Journal. Aug2009, Vol. 43 Issue 4, p226-232.

Graulich, Johannes; Sonntag, Joseph; Marcinkowski, Monika; Bauer, Karl; Kössel, Hans; Bührer, Christoph; Obladen, Michael; Versmold, Hans T. Complement activation by in vivo neonatal and in vitro extracorporeal membrane oxygenation. Mediators of Inflammation. Apr2002, Vol. 11 Issue 2, p69-73.

Flamant, Cyril; Hallalel, Fazia; Nolent, Paul; Chevalier, Jean-Yves; Renolleau, Sylvain. Severe respiratory syncytial virus bronchiolitis in children: from short mechanical ventilation to extracorporeal membrane oxygenation. European Journal of Pediatrics. Feb2005, Vol. 164 Issue 2, p93-98