INTRODUCTION

In the global scene of organ donation, Spain ranks first with an actual donor rate of 43.4 per million population (pmp), while Brazil ranks 28^thwith a rate of 14.6 actual donors pmp. In December 2017, 32,402 people were waiting for organ transplants in Brazil. In the same year, 10,629 potential donors were notified by the Brazilian National Transplant Center, but only 3,415 (32%) became effective donors, i.e. had at least an organ removed. Nationally, it is estimated that only about 40% of the annual need for kidney transplants is fulfilled; and for liver transplants, 30%¹.

The literature points to the failure when managing the actual donor as one of the reasons for not concluding the donation, for the disposal of organs or for transplantation of neighboring organs. Thus, performing the transplant and decreasing the wait list is not possible at times, which also produces unnecessary costs to the public system and health institutions, and affect the patients’ quality of life^2,3. In view of this, special cares for the potential donor are necessary to preserve the viability of the organs, since any malfunction can compromise the viability of the organs⁴.

Inefficiency of the systematization of the care for potential donors in intensive care units (ICUs) is reported in the literature. The absence of a specific protocol or of its implementation for proper maintenance is pointed, which interferes with the homogeneity of the interventions. The systematization of care for this patient is associated with the increased number of organs transplanted, the reduced loss of donors due to cardiovascular collapse, and the increased posttransplantation survival, since the viability of the organs is improved⁵.

The application of the nursing process (NP) in the maintenance of the potential organ donor can help in the proper care for this patient. The use of NP guides nurses in the practice and provides a bases to a systematic care process. The use of standardized language systems in the steps of diagnosis, intervention and results of nursing encourages critical thinking and clinical reasoning of nurses contributing, thus, to the monitoring of the care quality. The taxonomy of NANDA International (NANDA-I), which includes nursing diagnoses (ND), is one of the most known and used in several countries, including in Brazil^6,7,8.

A ND consists of title, definition, related or risk factors, and defining characteristics (DCs), in addition to a numeric code to be used in computer systems. The DCs are clues/inferences that can be observed and group as a manifestation of ND (for example, signs or symptoms). In the edition NANDA-I 2018-2020, two new categories of clinical indicators for most NDs that cannot be independently modified by nurses were included. The so-called risk populations are groups of people who share some characteristic making each member be susceptible to a particular human response. In turn, the conditions associated are medical diagnoses, procedures, medicines, among others⁹.

Studies showing the prevalent NDs for potential organ donors or for patients with brain death (BD) are scarce, despite the relevance of the topic. The most prevalent NDs identified in some studies were: Hypothermia, risk for deficient fluid volume, risk for decreased cardiac output, decreased cardiac output, ineffective airway clearance, impaired gas exchange, impaired bed mobility, risk for unsTable blood glucose level, risk for bleeding, risk for infection and decreased intracranial adaptive capacity^10,11.

The most prevalent NDs for potential organ donors or BD patients is related to physiological changes. These patients often have all the NDs cited for this population. However, the NANDA-I does not have a ND addressing this acute condition, because, if a list of NDs is very long, it hinders the prioritization of the interventions required for achieving the desirable results. Among the types of ND from NANDA-I, a syndrome may be present, being defined as “a clinical judgement related to a group of NDs occurring together, being more well-treated together through similar interventions”⁹.

In view of this, the ND whose title is impaired physiological equilibrium syndrome is being created. The definition of this ND is: "State of impaired physiological equilibrium syndrome that triggers a set of endocrine-metabolic symptoms, as well as hemodynamic, cardiovascular, ventilatory, nutritional, coagulation, immune and/or inflammatory changes that compromise the health and/or the organ functions".

Thus, the construction of this ND for this specific clinical condition and its future implementation in practice encourages the diagnostic accuracy and consequently the deployment of an adequate care plan that contributes to the improvement of the viability of organs for transplants, decreasing disposals and the use of neighboring organs resulting from failure when managing the potential donor. The decreased organ disposal and the use of neighboring organs reduce unnecessary costs to the public system and health institutions and the waiting list for transplants, improving the transplanted person’s quality of life.

OBJECTIVE

To identify possible DCs for the diagnosis of impaired physiological equilibrium syndrome for brain death patients and for potential organ donors in the literature.

METHOD

This is an integrative review of the literature (IRL) aimed at identifying the possible DCS of the developing nursing diagnosis. The IRL aims to synthesize and compare the data to develop a more comprehensive explanation of a specific phenomenon. The IRL has five steps: problem formulation, data collection, data evaluation, analysis and interpretation of data, and presentation of results¹². A protocol for this IRL was created with the five steps to characterize this study. This protocol was evaluated and validated by two nurses (not researchers of this study) with expertise in the subject and methodology of the study. Nurses assessed the steps of the IRL and gave suggestions concerning them.

Through the problem formulation the most important aspects to be considered in the study are defined¹². The problem of this study is: "How do we do to establish the DCs of the proposal of ND impaired physiological equilibrium syndrome?". Based on the problem formulation, the leading question was: "Which conditions/clinical events determine the physiological change in BD patients and potential organ donors?".

Data were collected through the search of articles published in the last 20 years (from 1997 to 2017) in Portuguese, Spanish and English. The time frame was set based on the publication of the organ transplant law in 1997¹³. Web of Science, PubMed and LILACS were the electronic databases consulted using the Health Sciences Descriptors (DeCs) and Medical Subject Headings (MeSH) with Boolean operators. “Brain death” OR “tissue donors” OR “tissue and organ procurement” OR “tissue and organ harvesting” AND “nursing diagnosis” OR “signs and symptoms” OR “hemodynamics” OR “monitoring physiologic” OR “endocrine metabolic management” were the descriptors/MeSh used. To preserve the accuracy in the collection and evaluation of data, these steps were performed independently by two researchers. When the results diverged, a third researcher evaluated these data.

In the data evaluation step, articles were selected based on their title and abstract, and then fully analyzed to answer the leading question of this study. Inclusion criteria were: studies that answer the leading question and full availability online. Exclusion criteria were: graduation work and monographs, dissertations and theses; format of publication such as research reports, letters, editorials, books, reviews, government publications (ordinances, laws and others); experimental studies with animals; publications in journals whose impact factor (IF) is lower than 0.5; and non-systematic literature reviews published in journals whose IF is lower than 1.0. Articles found in more than one database were analyzed only once. In this step, a data collection form was filled. The variables database, journal and country, impact factor, year of publication, authors and country, title, objective, method, and conditions/clinical events determining the physiological change were in the form.

In the analysis and interpretation of data, the information from the data collection form were synthesized in a summary Table. Through the summary Table, the data were evaluated critically to answer the leading question of this study. In addition, the convergences or divergences were highlighted, allowing discussing the results of the studies selected for the sample¹². The conditions/clinical events found in the IRL were related to possible DCs of the ND proposed.

Figure 1 outlines the process of selection of articles in the databases consulted, the number of articles that responded to the leading question and the number of items selected according to the criteria for inclusion and exclusion.

Figure 1. The selection of the articles in databases. Porto Alegre, RS, Brazil, 2017. 

RESULTS

The sample of IRL consisted of 37 articles that answered the leading question and met the criteria for inclusion and exclusion of the study. Box 1 shows the sample characterization.

It is observed that 23 articles of the sample (59%) are by authors from Europe, followed by North America with 11 (28%), in which US authors’ publications predominate, being almost all of them, with 10 articles. Most of the studies are recent publications, and 12 articles (33%) were published between 2012 and 2017. Five articles (13%) have IF higher than 10.0 and, among them, journals with high IF, being 20.212 and 72.406. Regarding the study design, observing a varied sample was possible, in which studies with strong-evidence design such as systematic review/meta-analysis, randomized controlled clinical trial and cohort study totaled eight articles (22%). However, nine articles (24%) comprising the sample were non-systematic literature reviews.

The result of IRL related to the leading question "Which conditions/clinical events determine the physiological change in BD patients and potential organ donors?" highlights the potential of the possible DCs of the proposed ND impaired physiological equilibrium syndrome for BD patients and potential organ donors. They were categorized in five groups of physiological changes, as shown in Box 2.

DISCUSSION

The results of the IRL allow support the problem of this study formulated in "How do we do to establish the DCs of the proposal of ND impaired physiological equilibrium syndrome?" by answering the leading question "Which conditions/clinical events determine the physiological change in BD patients and potential organ donors?". The 37 articles included in the sample of this study show several physiological changes found in the patient diagnosed with BD. The studies highlight and promote the discussion of physiological and/or organic changes, from the most frequently found to the rarest ones, in BD patients and potential organ donors.

The 44 possible DCs identified in IRL for the developing ND impaired physiological equilibrium syndrome were divided into five major groups: Endocrine-metabolic changes, hemodynamic and/or cardiovascular changes, ventilatory changes, nutritional changes, coagulation changes, inflammatory and/ or immune changes. Choosing to categorize the DCs in these five major groups aims to facilitate the visualization of the pathophysiological variations the nursing professional may find in BD patients. The nine DCs with a numeric code on the side are already NDs from NANDA-I, which corroborates the definition of a syndrome for this classification, that is, to be composed of pre-existing NDs and of other DCs⁹.

In the group Endocrine-metabolic changes, the DCs endocrine regulatory dysfunction, diabetes insipidus and altered diuresis were the most frequent in the sample (>50%). Other DCs that also showed significant frequency were electrolyte imbalance (f=16; 43%) and hypothermia (f=12; 32%). BD can impair the pituitary gland, causing hormone deficiencies, and affect the central thermoregulation¹⁴. Thus, the literature points that among the physiological changes caused by BD in the potential organ donor are diabetes insipidus, with occurrence between 37.5 and 78%, and hypothermia, with 75%^14,15. Untreated diabetes insipidus causes polyuria and results in hypovolemic shock and hypernatremia¹⁴. Studies highlight that hypernatremia is a frequent metabolic disorder and a failure of maintenance of the potential organ donors contributing to the primary graft failure¹⁶.

In the group Cardiovascular and/or hemodynamic changes, the DCs altered blood pressure and fluid volume deficiency were the most frequent (>50%). Changes in MAP (f=16, 43%) and CVP (f=12; 32%) were also significant in the sample. The "autonomic storm" in BD donors initially causes hypertension, and after the initial autonomic storm, hypotension and hypovolemia are the main problems in the potential organ donor maintenance. Hypotension should be avoided as it can contribute to the rapid deterioration of organ functions. Hypotension can be treated with a combination of intravenous fluids and vasoactive drugs. Cardiovascular instability increases rapidly, after increase in the intracranial pressure, resulting in myocardial injury. Invasive monitoring of PVC and MAP should be suited to age. It also can help the control of excess fluid administration, which should be avoided, since the latter can cause pulmonary edema^14,17.

In the group Ventilatory changes, the only significantly frequent DC was impaired spontaneous ventilation (f=37; 100%). All the other DCs showed frequency <20%. Impaired spontaneous ventilation is a ND from NANDA-I defined as "inability to start and/or maintain independent breathing that can support life.”⁹. This definition corroborates the etiology of BD, due to the fact that it causes inability to breathe independently and that all potential donors usually are on mechanical ventilation.

The nutritional changes in potential organ donor were not significant in the sample; however, the DCs anemia (f=2; 5%) and imbalanced nutrition (less than body requirements) (f=1; 3%) were cited. The coagulopathy, fluid administration and bleedings can cause anemia¹⁸. Regarding nutrition below the body’s needs, the importance of nutritional evaluation for an appropriate enteral and/or parenteral diet is evident.

Coagulation, immune and/or inflammatory changes were not frequent≤32%) compared with other groups as well. However, the plasminogen activator released by brain injury results in changes in coagulation (activated thromboplastin and prothrombin time and thrombocytopenia). Thus, bleeding complications may occur¹⁴. BD also triggers a systemic and local inflammatory response that consists of complement and endothelium activation, release of cytokines and chemokines, and flow of leukocytes to organs - which can cause tissue damage and ischemia injuries in the organs, contributing to graft rejection. Therefore, BD is similar to systemic inflammatory response syndrome¹⁹. In relation to immunological changes, the number of leukocytes may increase due to brain damage, systemic inflammatory state or nosocomial infection¹⁴.

An exploratory-descriptive qualitative study aimed to understand nursing scholars’ work when organizing the search of organs faced with the potential donor maintenance in a teaching hospital in Northeastern Brazil, promoting visibility and opportunity to evaluate the nursing practice itself. This study pointed out many care provided by these professionals and highlighted the need for specific knowledge for the care of this patient, such as BD physiological manifestations, drug therapy, as well as the need for understanding the normal physiological functioning to notice changes²⁰. The absence of tools and instruments for the potential organ donor maintenance and the non-use of NP and of a standardized language in the practice hinders the clinical reasoning, and may affect significantly the quality of the patient’s care due to its complexity.

CONCLUSIONS

The analysis of the articles allowed answering the leading question of this study and identifying possible DCs of the developing ND entitled impaired physiological equilibrium syndrome. Studies from different parts of the world and published in journals of impact were found, which reflects the relevance of the theme.

Performing a concept analysis to increase the level of evidence of the ND is suggested, in addition to content validation by experts and clinical validation to define which are the DCs found in the literature, providing a better support and accuracy for the ND in practice and thus defining which DCs will be part of the ND.

Considering the modifications made in the NANDA-I 2018-2020, the need for analyzing which DCs are considered associated conditions and risk populations will exist. NANDA-I also recommends structuring the new ND into seven axes, including domain and class. Moreover, NANDA-I suggests listing at least two interventions from Nursing Interventions Classification and a result from Nursing Outcomes Classification linked to the ND. After all these steps, the ND will be sent for analysis of NANDA-I for publication.

A limitation of this study is the fact that the IRL was performed using only the BD as related factor and only in the context of the potential organ donor maintenance. Replication of this study with other factors specified as circulatory death is suggested, for example, with other possible patient populations in which this new proposal can be applied.

The practical use of this proposal can provide a better systematization of care, enabling the proper potential donor maintenance and consequently a better viability of the organs offered for transplantation and contributing to improving posttransplantation survival. In addition, developing this ND can contribute to the taxonomy of NANDA-I and to development of nursing knowledge in the maintenance of potential organ donors, contributing to teaching and research.