Urgências e Emergências Oncológicas: Revisão Integrativa da Literatura Urgencias y Emergencias Oncológicas: Revisión Integrativa de la Literatura

Introduction: Oncological emergencies are acute conditions caused by cancer or its treatment, which require rapid intervention. Objective: To analyze and synthesize the scientific production related to patient care with emergencies and oncological emergencies. Method: Integrative literature review with PubMed, Cinahl, Embase and Lilacs queries in February 2018, with the descriptors Emergencies AND Oncology OR Neoplasm, with no time restrictions. Results: Selected 55 articles, published from 1987 to 2017; with a weak or moderate level of evidence (96.3%); 54.5% of the articles covered structural-obstructive gastrointestinal emergencies, 10.9% respiratory tract, 7.2% infections and neurological system, 5.4% cardiac, abdominal and metabolic emergencies and 3.6% hepatic emergencies. Conclusion: Oncological emergencies should be better studied, recognized and understood by the team, so that there is an improvement in the prognosis and quality of life of the patients.


INTRODUCTION
Oncologic emergencies are acute conditions caused by cancer or its treatment, which require rapid intervention because they involve imminent risk of life or risk of permanent serious damage 1 .
The care to oncology urgencies or emergencies has a key role in the reversion of cases that head to death. It should further the improvement of the quality of life and prevention of sequelae arising from the complications 2 .
The lengthening of the survival of the patients with cancer may lead to the evolution of the disease, which associated to comorbidities and toxicities of the treatment may increase the cases of oncologic emergencies. The evolution may be because of metastasis and has a rate of incidence of 70% of cancer cases 3,4 .
There are several forms of classification of these emergencies, according to tumor-related harms and those provoked by the treatment 5 or by structural, metabolic and secondary emergencies to the treatment 4,6 ; others propose the division pursuant to the systems affected 2 and, ultimately, there are those that consider the symptoms and consequences of the harms as actual emergencies 7 .
Errors or delays in care may result in death or irreversible damages. The capacitation of professionals to identify rapidly the problem and apply the proper therapy can modify the prognosis or improve significantly the quality of the life of these patients 6 .
The comprehension of these acute conditions is essential for the team who provides care to patients in oncologic emergency units where screening, anamnesis and physical exam are carried out in order to decide which is the best possible conduct and approach 8 .
However, the education background of the healthcare team is not always adequate, which makes many professionals to feel unprepared to deal with the complexity of the oncologic harms, where clinical alterations mingle with evolutive conditions of the neoplasms and aggressive toxicities of the treatment 8 .
Therefore, because of the necessity of approaching the scientific production related to oncologic emergency cases with the clinical practice, the objective is to analyze and synthetize the scientific production related to the patient care in oncologic urgencies and emergencies.

METHOD
It is an integrative review of the literature, constructed from the following stages: development of the steering question, search of the primary studies in the databases, extraction of the studies data, assessment of the studies selected, analysis and synthesis of the results and presentation of the review 9 .
To reach the goal, the following steering question was elaborated: What are the available scientific evidences about oncologic urgencies and emergencies associated to patient care?
The collection of the data was carried out in February 2018. The selection of the articles was made in the databases US National Library of Medicine (PubMed), Cumulative Index to Nursing and Allied Health Literature (Cinahl), Excerpta Medica Database (Embase) and Latin-American and Caribbean System on Health Sciences Information -LILACS.
The descriptors emergencies, oncology, neoplasm, were combined in different forms as seen in Table 1.
The inclusion criteria for the pre-selections of the studies were: studies in English, Portuguese or Spanish published in journals, which approached the care to the patient in oncologic urgencies and emergencies.
The non-primary articles, as those of opinions and reviews were excluded and those that after the full reading failed to meet the objective of this review. No limits were determined in relation to the year of publication of the articles.
It was used the validated instrument 10 to collect and analyze the data that was adapted to meet the study objectives. The pre-selection of the studies was carried out through the thorough reading of titles and abstracts; the articles were fully read for the final selection.
The topics of interest approached in the instrument were: title, year of publication, idiom, origin country of the publication, database, objective, method, results, conclusions/recommendations and level of evidence.
For the level of evidence, it was used the classification suggested by Melnyk and Fineout-Overholt 11 , which classified the studies in seven levels: 1 -systematic review or meta-analysis of clinical trials randomized controlled; 2 -at least one well designed controlled randomized clinical trial; 3 -no randomized clinical trials well designed; 4 -well designed cohort and case-control; 5 -systematic review of qualitative and descriptive studies; 6 -unique descriptive or qualitative study; 7 -opinion of authorities and/or report by specialists committees. The identification, selection and inclusion process was divided in three stages. The first stage comprehended the verification of duplicate articles, what was undetected, reaching 693 articles.
The second stage consisted in reading the titles and abstracts of the articles, under the scrutiny of the inclusion and exclusion criteria. Thus, 233 articles were chosen.
In the third stage, the 233 articles were read in full, 177 articles were removed because they failed to meet the inclusion criteria and did not answer the steering question of this review.

RESULTS
The English is the idiom of 76.3% of the published articles, 14.5% in Spanish and 9% in Portuguese.
In the United States of America, 21.8% of the studies were conducted, 7.2 % in the United Kingdom and the same percent in Brazil; 5.4%, South Korea, China and Spanish each one, 3.6% in Singapore, Italy, Germany, Israel, Argentine and Chile each one; 1.8% in France, Sweden, Australia, Japan, Slovenia, The Netherlands, East Europe, Mexican, Venezuela, Peru, Canada, Ecuador and Thailand.
After reading the studies, they were divided in three groups: studied oncologic emergency, therapeutic or treatment implemented and endpoints.
Thirty authors described the endpoint of the emergencies of the obstructive-structural gastrointestinal tract. There was a predominance of the safe use of stents for colon clearing, and if considered safe, it diminishes the necessity of colostomy, mortality and improves the quality of life.
In addition, it was described that the emergency surgery could be lethal; it could increase significantly the morbimortality and worsens the prognosis when compared to elective surgeries. Despite this, the surgery must be conducted. . Table 3 presents the main endpoints and references of the studies for the respiratory, cardiovascular, infectious and neurologic emergencies (17 studies).
For respiratory emergencies, six studies were encountered, mainly with the description of techniques as tracheal dilatation, cricothyrotomy and prosthetics for better recovery of the ill.
In the endpoints of three cardiovascular emergencies studies, it were described the necessity of quick diagnosis and conduct in face of SVCS.
Four articles about infectious emergencies addressed the use of standard protocols to reduce the time to administer the first dose of antibiotics in case of fever and neutropenia.
The neurological emergencies were addressed in four studies where the authors emphasized the need of quick and accurate interventions to reduce the morbimortality. Table 4 presents the main endpoints and references of the studies encountered for abdominal, hepatic and metabolic emergencies (eight studies).
The abdominal emergencies addressed in three articles describe mainly the symptoms as peritonitis and abdominal pain resulting from metastasis.
In the hepatic emergencies, two articles were encountered about exploratory laparotomies and  chemoembolization in the attempt to reduce mortality and complications.

Autoextensible metallic stent does not affect the rate of creation of the stroma, favors elective minimal invasive surgery and reduces post-operatory complications
The metabolic emergencies described in three articles brought up the use of chemotherapy of urgency and interventions to improve lactic acidosis, which drew the attention to the possibility of pseudo-hyperkalemia in severe leukocytosis to avoid iatrogenic hypokalemia.

DISCUSSION
The results indicate that the investigation about the care provided to the patient under oncologic emergencies is not recent (1987) and the number of researches grows constantly every year, mostly between 2011 and 2017, where the rates of mortality increased substantially 3 .

Authors Studied Emergencies Main endpoints
Piastra et al. 41 Ventilatory difficulty Intensive therapy is essential for the recovery of the patient with severe neoplasm of the mediastinum, in addition to anti-neoplasm therapy Aneeshkumar et al. 42 Airway obstruction Cricothyrotomy opens a safe and rapid airway, with little trauma Godbout et al. 43 There was no difference in the survival with the administration of the "distress protocol" (sedation for palliative care) among those who received and those who did not receive Nicolai et al. 44 The endoscopic dilatation of the balloon through an endotracheal tube with implantation of stent succeeded, it allowed extubation and release of the child from ICU Tasci et al. 45 Bronchoscopy is the golden standard to confirm the etiology subjacent to the central airway obstruction  49 There were no advantage of the treatment combined with chemotherapy and radiotherapy in this series Cash et al. 50 Febrile neutropenia The use of the standard process reduces the time for the first dose of antibiotic in case of fever and neutropenia Pakakasama et al. 51 Guidelines for children with cancer and fever result in reduction of the adverse effects and improvement of survival Treatment includes early removal of the teratoma, intravenous immunoglobulin, methylprednisolone or plasmapheresis The world estimate shows that in 2012, there were 14.1 million new cases of cancer and 8.2 million of deaths. It was observed a discreet predominance of male cases in the incidence (53%) and mortality (57%) 66 .
Overall, it were observed higher incidence rates in the developed countries (North America, East Europe, Japan, South Korea, Australia and New Zealand). Intermediate rates are seen in South and Central America, East Europe and in great part of Southeast Asia (including China). The lower rates are found in great part of Africa, Southern and West Asia (including India) 66 .

Authors Studied Emergencies
Main endpoints Löhr 58 Abdominal pain, diabetes Pancreas cancer needs an effective approach with rapid diagnosis and multiprofessional approach Lee et al. 59 Peritonitis, anemia, hypoalbuminemia, Urgency surgery of peritonitis because of cancer, pre-operatory anemia and pre-operatory hypoalbuminemia exhibit high mortality Albinagorta et al. 60 Commitment of the digestive tract Radical surgical approach offers better possibilities for these patients Parekh et al. 61 Rupture of the hepatocellular carcinoma Open laparotomy was replaced by transarterial embolization with rates equivalent to hemostasis, reduction of mortality in 30 days Chen et al. 62 Rupture of the hepatic carcinoma Emergency chemoembolization did not improve the endpoint and was associated to higher rates of mortality and complications Gardner et al. 63 Lactic acidosis Emergency chemotherapy was well succeeded in the reduction of lactate levels. The venous hemofiltration did not have effect in the reduction of lactic acidosis Alhaj et al. 64 Pseudohyperkalemia in one leukocytosis It should consider the pseudo-hyperkalemia in cases of severe leukocytosis to avoid iatrogenic hypokalemia Maloney et al. 65 Tumoral lysis syndrome The understanding of the risk factors for the tumoral lysis syndrome gives oncologic nurses a base for its prevention The majority of the studies (92.8%) was produced internationally, which shows the reduced production of national studies on the subject. The level of evidence for 56.3% was moderate. The studies reached similar approaches in what concerns recommendations for oncologic emergencies.
For tumor location, intestine cancer was the most studied. The most incident types of cancer in the world were lung (1.8 million), breast (1.7 million), intestine (1.4 million) and prostate (1.1 million) 66 .
The obstructive-structural of the gastrointestinal tract stood out among the oncologic emergencies, the intestinal obstruction was predominant. These are relatively common in patients with advanced cancer, the major causes being ovary carcinoma and rectum 67 .
The obstruction can be structural or pseudostructural as consequence of tumoral infiltration of the mesentery or smooth muscle, involvement of the celiac plexus or paraneoplastic neuropathy in patients with lung cancer of small cells and expansive lesion of tumors located in the region 67 .
The emergency surgeries showed a poor diagnosis when compared to elective surgeries 12,15,16,24,25,29 . But, the emergency surgery should not be denied or delayed for oncologic patients who need immediate intervention, even for those with the active disease 21 .
The emergency surgery for left and right colon cancer presented in the studies selected a better prognosis when performed in a stage with resection and primary anastomosis, without colostomy, not showing counterindications in elderly patients 14,18,21,23,26 .
Several studies demonstrated that stent implantation is quite safe and little invasive, with less morbidity and mortality when compared to emergency surgeries 11,[35][36][37][38]40 . However, it was not beneficial for stage IV colorectal obstructive cancer and if not implanted, it is anticipated a poor diagnosis when compared to those where stent was implanted successfully or to emergency surgery 33,34 .
Concerning airway obstruction in respiratory emergencies, cricothyrotomy is an agile form to obtain a safer airway in an emergency situation 42 . Bronchoscopy was described as the golden standard to confirm the etiology of the obstruction 45 .
SVCS requires immediate treatment and diagnosis to obtain a better prognosis, it is necessary to have clear guidelines conduct to improve the agility and efficacy of the treatment 47,48 .
The infectious emergencies describe guidelines to treat febrile neutropenia that can evolve to septic shock. The recommendation is to have a standard protocol to reduce the adverse effects and the improvement of survival 50,52 .
The neurologic emergencies as the SCM and raise of the intracranial pressure have a poor prognosis and should be diagnosed and treated as partial or total loss of the motor and sensitive function of the posterior part of the spinal medulla of the neoplasm-affected region, as shown in the complete neurological exam of the sensitive Revista Brasileira de Cancerologia 2018; 64(4): 539-548 and motor function, which is the first step of the diagnosis of this emergency 54,55 .
Usually, the abdominal oncologic emergencies are late diagnosed, it is common that the diagnosis is done in the emergency. Because of a poor prognosis with a reduced survival time, as in pancreas cancer, these oncologic emergencies are addressed in but a few studies for diagnosis and new methods of intervention 58 .
So, if possible, the surgical treatment is always recommended and waiting time for the procedure may be associated to adjuvant chemotherapy to stabilize the tumor 58,60 .
In hepatic emergencies, the researchers discussed the exploratory laparotomies and chemoembolization to control the tumor, there were no improvement of the rates of complications and mortality 61, 62 .
The metabolic emergencies ponder about the use of urgency chemotherapy and interventions to improve the lactic acidosis and hyperkalemia considering pseudohyperkalemia in cases of severe leukocytosis postoncologic treatment 64,65 .

CONCLUSION
The oncologic emergencies related scientific production had a substantial expansion in the last years, a consequence of the development of antineoplastic treatments that enabled a major survival to the oncologic patients and high incidence of acute manifestations of the disease.
The majority of the studies presented weak or moderate level of evidence. In this way, it is perceived the necessity of studies with more substantial evidence to favor better conducts towards oncologic urgencies.
In this study, the oncologic emergencies caused diverse disorders, mainly in the neurologic and gastrointestinal systems. These are important and should be acknowledged and understood by the team to improve the diagnosis and quality of life of the patients.

CONTRIBUTIONS
All the authors participated of the study conception and design, analysis and interpretation of the data, wording and review and approval of the final version.

DECLARATION OF CONFLICT OF INTERESTS
No conflicts of interest to declare.

FUNDING SOURCES
None.