Postoperative complications in adult patients undergoing surgery with confirmed infection by SARS-CoV-2: An integrative review

Objective: to analyze the evidence available in the literature about postoperative complications in adult patients undergoing surgical procedures with confirmed infection by SARS-CoV-2. Method: an integrative literature review conducted in the CINAHL, EMBASE, LILACS, PubMed, Scopus and Web of Science databases, as well as in the gray literature. The references identified were exported to the EndNote manager and, subsequently, to the Rayyan web application for study selection. The stages of sampling, categorization of studies, evaluation of the studies included, interpretation of the results and knowledge synthesis were performed by two reviewers independently and in a masked manner. The data were analyzed descriptively. Results: of the 247 articles identified, 15 were selected to comprise this review. The prevalent postoperative complications in patients infected with SARS-CoV-2 were the following: cough, dyspnea and hypoxia, need for invasive mechanical ventilation or not, admission to the intensive care unit and death. Conclusion: the most reported postoperative complications in the studies evaluated were respiratory-related, followed by cardiovascular complications. The importance of preoperative screening for COVID-19 is highlighted, as well as of the monitoring and tracking of confirmed cases in the postoperative period, as these actions exert an impact on reducing the occurrence of complications related to SARS-CoV-2.

To relieve pressure on the health system and minimize the risk of nosocomial spread of COVID-19 during surgical procedures, specialized societies determined that elective surgical interventions be suspended or postponed.
However, urgent and emergency procedures, as well as those with urgent surgical indication, should undergo a careful assessment on a case-by-case basis, to analyze the risk of transmission and postoperative complications (9)(10) .
In addition to that, measures to prevent and avoid the spread of the virus within the surgical environment highlighted the correct use of personal protective equipment and the reduction in the transit of personnel within operating rooms during invasive procedures (2,8) .
Studies evaluating the impact of postoperative complications in patients infected with SARS-CoV-2 are still scarce in the literature. Despite this, it was evidenced that, due to proinflammatory cytokine and immunosuppressive responses related to surgery and mechanical ventilation, such patients are especially susceptible to subsequent pulmonary complications, changes in laboratory tests, acute kidney injury, arrhythmia, acute cardiac injury, shock and secondary infections (11)(12)(13)(14) .
Identifying postoperative complications early is relevant to reduce morbidity and mortality in this period.
A number of studies show that previously undiagnosed COVID-19 can complicate postoperative recovery (13,15) .
In this sense, the importance of the Nursing team in the post-anesthetic recovery room and in the inpatient units is highlighted, as this is the professional category that stays the longest with the patient, being responsible for evaluating complications and implementing interventions aimed at preventing problems and promoting health recovery (13,15) .
Despite the publication of guidelines to guide the ways of reorganizing surgical activities during the COVID-19 pandemic, the scientific production related to the management of surgeries is incipient, particularly with regard to the treatment of postoperative complications.
Added to this context, the nurse is the protagonist to early identify the clinical manifestations that may be related to such adversities and make evidence-based clinical decisions to solve them. Thus, synthesizing the evidence to increase the safety of surgical patients exposed to SARS-CoV-2 is urgent and necessary, with the potential to directly influence the clinical outcomes of these patients.

Study type
This study consists of an integrative literature review, filed on the Open Science Framework platform, whose registration is available at https://osf.io/be97s/, which enables to gather and synthesize the production of knowledge on a given subject matter, ensuring, through the wide number of studies, theoretical deepening on different perspectives of the same theme (16) . The study was conducted in six stages (16) , namely: identification of the theme, sampling, categorization of the studies, evaluation of the studies included, interpretation of the results and knowledge synthesis, respectively. The question of this integrative review was guided by the PECO strategy (17) (Figure 1)    After the search, the results were exported to the EndNote Basic (18) reference manager, online version, to remove duplicate references. Subsequently, they were imported into the Rayyan web application, which can be accessed through https://rayyan.qcri.org, for the selection of studies.
In the Rayyan web application, the studies were evaluated and selected by two reviewers independently and blindly, first by reading the titles and abstracts, in order to verify if they met the eligibility criteria of this review. The studies considered eligible were then analyzed by reading the text in its entirety, according to the eligibility criteria. In case of disagreement between the reviewers, a third reviewer with expertise in the subject matter was consulted.

Period
The search in the electronic databases was carried out on August 19 th , 2020.

Selection criteria
Primary

Instrument used to collect the information
The data from the studies were collected using an adapted form (19) , which includes the following: reference and year of publication, country where the study was conducted, methodological characteristics [study design according to the nomenclature used by the author(s) and sample] and main outcomes (postoperative complications).

Data treatment and analysis
The data were analyzed qualitatively, synthesizing the evidence from the primary studies in a descriptive way.

Results
order to exclude the possibility of infection, considering the incubation period of the virus for patients with negative results (32,35) . Some authors report difficulty in diagnosing postoperative SARS-CoV-2 infection (30,36) , as the symptoms are similar to those of common postoperative complications, such as increased body temperature (15,(25)(26)(30)(31)(32)35) .
Regarding the methodological quality of the primary studies included, eight were classified as with low risk of bias and, therefore, they present good methodological quality. Six studies were classified as with moderate risk of bias and moderate methodological quality, and only one as with high risk of bias and low methodological quality.
Regarding the level of evidence, four studies presented level II, seven were level IV and four, level V.

Case report
To describe a cardiac surgery with a poor outcome due to postoperative COVID-19 infection, in addition to changes in the practice during the pandemic.
Male patient undergoing coronary artery bypass surgery.
In the postoperative period, the patient evolved with respiratory complications attributed to COVID-19, such as hypoxia, dyspnea and fever in the 1 st PO ¶ , with evolution to death in the 9 th PO ¶ . The patient was not tested during the preoperative period, and the waiting time in the hospital was clearly too long.

Crosssectional study
To present the experience related to postoperative morbidity and mortality associated with COVID-19 after emergency gastrointestinal surgery.
A total of 100 patients were analyzed. The overall postoperative respiratory complication rate was 5%, with an infection rate of 3% for COVID-19. Eleven patients had non-respiratory postoperative complications, including urinary tract infection, surgical wound infection and central catheter-related infection, acute coronary syndrome and cardiac arrhythmia. Five patients developed postoperative respiratory complications, including changes in the respiratory tract, pulmonary embolism and respiratory failure.

Case report
To present the experiences obtained with a patient who presented a severe burst-type lumbar fracture complicated by an occult SARS-CoV-2 infection.
Male patient, evaluated during the COVID-19 incubation period. On the 3 rd PO ¶ , the patient developed chills and high fever. A chest computed tomography scan showed ground-glass opacity in the lower part of the right lung and the test for SARS-CoV-2 was positive.

Case series
To report the characteristics and prognosis of three women diagnosed with COVID-19 after oncological gynecological surgeries.
SARS-CoV-2 infection was observed in three patients during the postoperative period. The main complications reported were fever (within 2 days after the surgery), cough and hypoxemia. In addition to that, changes were observed in the imaging exams, compatible with viral pneumonia ten days after the surgery.

Crosssectional study
To retrospectively review 34 patients with acute abdomen who underwent emergency surgeries during the COVID-19 outbreak.
Six cases of pneumonia due to COVID-19 were identified. The patients with COVID-19 presented worse liver function and coagulation indicators and longer hospital stays. Postoperative complications occurred in two patients: one had aspiration pneumonia and the other presented multiple organ dysfunction. Both required mechanical ventilation, and one of them evolved to death.
Moderate IV * ID = Identification; † JBI = Methodological quality assessment using the Joanna Briggs Institute tool, being considered as with high risk of bias when the study reached a "yes" score below 49%, moderate when the "yes" score reached 50% to 69%, and low when the study reached a "yes" score above 70%; ‡ such as atelectasis. The respiratory system can take up to six weeks to return to its baseline condition after general anesthesia for major surgeries (38) .

ICU = Intensive
However, the incidence of postoperative respiratory complications during the pandemic is even higher. A multicenter international cohort study, carried out between January and March 2020 in 235 hospitals from 24 countries, with 1,128 patients undergoing surgeries with confirmed infection by SARS-CoV-2, found a 51.2% incidence of pulmonary complications (9) . This rate is higher than that identified in a multicenter cohort study, carried out pre-pandemic from 2014 to 2015, in 211 hospitals from 28 European countries with 21,694 adult patients undergoing general anesthesia, in which the incidence of postoperative pulmonary complications was 7.6% (39) .
Among the risk factors for the development of respiratory complications in the postoperative period, comorbidities (systemic arterial hypertension, chronic obstructive pulmonary disease and cancer) stand out, as well as extrinsic factors such as smoking and the surgical procedure itself, which can lead to impairment of the immune system cells (40)(41) . Added to these factors, the infection by the new coronavirus presents itself as an additional risk factor for worsening of the postoperative complications, since SARS-CoV-2 presents tropism for the cells of the respiratory system (9,(42)(43)(44)(45) and increases the pro-inflammatory cytokines and chemokines levels, correlated with disease severity (46)(47) .
The signs of SARS-CoV-2 infection in the postoperative period can manifest themselves very similarly to common infections, such as surgical site infections, hindering COVID-19 diagnosis. Therefore, fever episodes in the postoperative period, even if incidental and without the presence of other signs and symptoms, must be carefully investigated, as they can be related to surgical or respiratory complications arising from SARS-CoV-2 or from another microorganism infection (30,36) .
When perioperative SARS-CoV-2 infection is identified, the prognosis tends to be worse, with a significant increase in the mortality rates, length of stay  (9,45) .
This synthesis also evidenced other complications among the surgical patients infected with SARS-CoV-2, mainly cardiovascular complications such as arrhythmia, acute cardiac injury and acute myocardial infarction.
Corroborating these results, a recent study showed that SARS-CoV-2 has a pathogenicity that can increase myocardial damage (48) . The results of this research showed cases of acute cardiac injury, shock and arrhythmia in 7.2%, 8.7% and 16.7% of the infected patients, respectively, being more prevalent among those who needed intensive care. Based on these data, careful attention must be given to cardiovascular protection during treatment for COVID-19 (49) , especially in the postoperative period.
The Nursing team plays a leading role in the care provided to surgical patients. Perioperative Nursing care based on scientific evidence is essential to prevent postoperative complications (50)(51) and also to prevent