Clinical indicators, nursing diagnoses, and mortality risk in critically ill patients with COVID-19: a retrospective cohort

ABSTRACT Objective: To identify clinical indicators and nursing diagnoses with the highest risk of mortality in critically ill patients with COVID-19. Method: Retrospective cohort with the population of adults and elderly people with COVID-19 from an Intensive Care Unit. Categorical variables were described using absolute and relative frequencies and risk factors for mortality using Cox regression, with a confidence interval of 95%. Results: The main clinical indicators of COVID-19 patients were dyspnea, fever, fatigue, cough, among others, and the Nursing Diagnoses at higher risk of mortality were Ineffective protection, Ineffective tissue perfusion, Contamination, Ineffective Breathing Pattern, Impaired spontaneous ventilation, Acute confusion, Frailty syndrome, Obesity, and Decreased cardiac output. It is worth mentioning that there was little information about the diagnoses of Domains 9, 10, and 12. Conclusion: This research infers the need to monitor the clinical indicators dyspnea, fever, fatigue, cough, among others, and the Nursing Diagnoses with the highest risk of mortality Ineffective protection, Ineffective tissue perfusion, Contamination, Ineffective Breathing Pattern, Impaired spontaneous ventilation in critically ill patients.


INTRODUCTION
In the International Year of the Nurse, 2020, nurses around the world faced a great professional challenge to care for patients with the disease caused by the new coronavirus, COVID-19, which emerged from an epidemic in China, and is characterized by high transmissibility and morbidity and mortality (1) .
On December 3, 2021, it had already affected more than 262 million people, with more than five million dying. The most affected continent is the American, with more than 97 million cases. In Latin America, Brazil was the second country with the highest confirmed incidence and mortality, with more than 22 million cases and 614,000 deaths, whose risk factors for mortality shall be investigated aiming at the early identification of clinical indicators present in patients with COVID-19 (2)(3) .
Thus, in the context of the COVID-19 pandemic, health care services have demanded rapid and systematic assistance from the Nursing team, whose actions are related to the Nursing Process (NP), which is the scientific method used by the nurse to identify, plan, intervene, and assess care (3) .
The NP highlights the Nursing contribution to the population's health care, increasing visibility and professional recognition. The NP is subsidized by Resolution No. 358 of 2009, of the Federal Nursing Council (COFEN) and consists of five stages: Data/History Collection, Nursing Diagnosis, Planning, Implementation, and Assessment (4)(5) .
The Nursing History is NP's first stage and consists of the patient's history taking and physical examination. At this stage, the nurse identifies symptoms and signs, which can also be called clinical indicators/clinical manifestations, which will serve to prepare the Nursing Diagnoses (ND). The NDs are Nursing problems identified through History taking that they need to receive Nursing interventions, and in case of the presence of associated conditions, interventions from other members of the interdisciplinary team (4) . The NDs are listed in Nursing taxonomies, with the NANDA-international, Inc. (NANDA-I) being chosen for this research, due to the greater familiarity of the researchers (4)(5) .
In patients with COVID-19, it has been reported that the main symptoms and signs of the disease are fever, cough, dyspnea, pulmonary auscultation with adventitious sounds, myalgia, running nose, diarrhea and anosmia, whose clinical indicators can infer NDs, such as impaired spontaneous ventilation, impaired gas exchange, ineffective peripheral tissue perfusion, risk of pressure injury, risk of corneal injury, among others, as described by the Nursing Process Research Network (RePPE), in its tutorial and data collection instrument for the elaboration of Nursing diagnoses, outcomes, and interventions for the care of patients in critical condition during the COVID-19 pandemic (6)(7)(8)(9)(10) . However, these suggested nursing diagnoses have not been clinically validated, and there may be others.
Moreover, several articles reported that age over 60 years, male sex, presence of chronic diseases, and unhealthy lifestyle are higher risk factors for morbidity and mortality in patients with COVID-19 and, in the context of NDs, these factors are called risk/related factors and associated conditions, whose interventions need the help of other professionals for their resolution (5)(6)(7)(8)(9)(10) .
In COVID-19, respiratory manifestations have been emphasized for clinical observation, such as increased respiratory rate, dyspnea, use of accessory muscles, low oxygen saturation, among others, which can suggest the NDs Ineffective Breathing Pattern (IBP), Impaired Gas Exchange and Impaired Spontaneous Ventilation, for example, whose care interventions will be directed to dyspnea relieve, correcting acid-base imbalances (especially respiratory acidosis) and establishing normal respiratory function (10)(11)(12) .
Thus, it is thought that identifying the Nursing diagnoses with a higher risk of mortality in patients with COVID-19 can help in the surveillance of clinical indicators and in the early targeting of interventions aimed at patients' recovery. In this regard, the question of this study is: What are the clinical indicators and nursing diagnoses with the highest risk of mortality in critically ill patients with COVID-19?
To answer the study question, the objective of this work is to identify clinical indicators and nursing diagnoses with the highest risk of mortality in critically ill patients with COVID-19.

Design of stuDy
This is a retrospective cohort study with patients hospitalized due to COVID-19 complications, in an Intensive Care Unit, from March to December 2020.

PoPulation, local anD selection criteria
The sample consisted of all (57) adult and elderly patients, diagnosed with COVID-19, who were hospitalized in the COVID-19 ICU of a hospital in the Brazilian Amazon, for at least 72 hours, and who died. The information was collected from the patients' clinical records, at the Medical Archives Service (SAME), from the admission to the discharge/death of the patient in the ICU. Data collection was carried out from January to September 2021.

DePenDent Variable
The dependent variable was death of patients with COVID-19.

inDePenDent Variables
The independent variables were the sociodemographic, the clinical ones, and the NDs, with the first two being variables that are ND's clinical indicators (defining characteristics).
The sociodemographic variables listed were: medical record number, date of birth, date of onset of symptoms, date of diagnosis, date of discharge or death, length of stay (days), age (years) and color (white, brown, yellow or black), with the last two factors being related to possible ND.
The NDs were selected from the NANDA-I taxonomy, collected in a dichotomous way and discriminated by presence or absence, according to what was established in the ICU-COVID-19 NP instrument.

Data collection ProceDure
Data were collected using a questionnaire created digitally in the software Research Electronic Data Capture (REDCap) (14) .
REDcap was created in 2004 by researchers at Vanderbilt University (Tennessee, United States). It has the financial support of the National Institute of Health (NIH), and has technical-scientific support from the REDCap Consortium, made up of more than 2,600 institutions in more than 117 countries on six continents. It was introduced in Brazil in 2011 through the Medical School of Universidade de São Paulo (FMUSP). Currently, the REDCap Brasil Consortium is the entity in the country responsible for the official representation of the tool at more than 100 renowned institutions (14) .
The data collection procedure for the research was performed by a nursing resident of the Multiprofessional Residency Program in Intensive Care at the Universidade Federal do Acre.

Data analysis anD treatment
The analysis was performed with the software SPSS, version 22.0. Continuous variables were analyzed by measures of central tendency (minimum, maximum, mean, and standard deviation) and categorical variables by absolute and relative frequencies.
The NDs with mortality risk were identified by Cox regression, using the magnitude measure Hazard Ratio (HR), considering a confidence interval of 95%.
The NDs with the highest risk of mortality were: Ineffective protection; Ineffective tissue perfusion; Contamination; Ineffective Breathing Pattern; Impaired spontaneous ventilation; Acute confusion; Frailty syndrome; Obesity, and Decreased cardiac output, all of them with 95% CI. It is worth mentioning that there was little information about the NDs of Domains 9, 10 and 12, as can be seen in Table 3.  Many patients were over 60 years of age and had comorbidities, risk factors for COVID-19 mortality (7)(8)11,13) . In addition, brown and black patients, common characteristics of patients in the North region of Brazil, were the majority among those hospitalized with severe cases in the ICU (11.16) , whose unit was established in a few days due to the lack of intensive care beds in the state with a simpler technological structure when compared to large centers, which leads to a social discussion in the COVID-19 pandemic (11,(16)(17)(18)(19) .
In a multicenter cohort study carried out in California, high-tech hospital admission was a protective factor against unfavorable outcomes, unlike the ICU of the study, whose socioeconomic disparities can interfere with survival and deserve intervention and political-sanitary discussion (16)(17)(18)(19) .
Regarding the clinical indicators presented by the patients in the study, related to the higher risk of mortality from COVID-19, the following stand out: dyspnea, fever, fatigue, cough, increased heart rate, arrhythmias, and obesity. These manifestations are defining characteristics of the NDs IBP, Impaired spontaneous ventilation, Decreased cardiac output, Ineffective tissue perfusion, Contamination and Ineffective Protection, which shall undergo early surveillance for these symptoms and signs and referral for Nursing interventions (5,9,11,13,(20)(21) .
The ND Ineffective protection refers to the decrease in the ability to protect oneself from internal or external threats characterized by the presence of dyspnea, fatigue, and cough (4) . This diagnosis has, as populations at risk, extremes of age, reaffirming the results obtained in the research in which older patients are more vulnerable to mortality, and should be the priority in preventive practices such as vaccination against COVID-19 (5,9,(20)(21) .
The RePPE suggested, as Nursing activities for the NDs Ineffective tissue perfusion and Decreased cardiac output, Shock Control, Medication Administration, Hydroelectrolytic Control, and Hemodynamic Regulation, with the nursing prescriptions Monitoring and vital signs assessment, Control of urinary output and fluid balance, Observation and reporting in case of systolic blood pressure being lower than 90 mmHg and of the presence of arrhythmias on the monitor, perfusion status (extremity temperature, skin color) assessment, as well as recording and evaluation of Central Venous Pressure, Pulmonary Artery Pressure, Pulmonary Capillary Pressure, Cardiac Output, and Venous Oxygen Saturation, if monitoring catheter installed, and Administration of fluids according to institutional protocol (3,5,9) .
Ineffective Breathing Pattern (IBP) is an ND characterized by inspiration and/or expiration that does not provide adequate ventilation; it is related to fatigue, pain, obesity, and anxiety, and is characterized by the presence of dyspnea, tachypnea, and abnormal breathing pattern (5) . This ND had a 100.0% frequency and an 88.0% higher risk for mortality in patients with COVID-19. In a study in the same ICU, but without the presence of COVID-19, the frequency of this ND was 66.7%, revealing a large increase in the population of patients with COVID-19 (11) .
The ND Impaired spontaneous ventilation is the progression of the clinical worsening of patients diagnosed with IBP, in which the patient is unable to maintain spontaneous ventilation, requiring ventilatory support and, in most cases, caused by respiratory muscle fatigue (5) . These patients have to be evaluated at the bedside by the nurse, who shall assess respiratory rate, measure and control fluid balance, acid-base disorder, perform pulmonary auscultation, monitor signs of level of consciousness lowering, among others, always discussing with the multidisciplinary team, which will help in the prescription of drugs and in respiratory physiotherapy, aiming at improving the respiratory condition and the respiratory muscles fatigue (5,9,15,(20)(21) .
The ND Deficit in self-care for bathing and feeding are very frequent in critically ill ICU patients, due to the patient's inability to perform hygiene and feeding measures correctly. In COVID-19 patients, specific care is recommended for bed baths, such as disposable baths, oral hygiene with oxygen peroxide or povidone in conscious and oriented patients and with 0.12% chlorhexidine, every 12 hours, in intubated patients; also, giving preference to oil-free moisturizers and using a protocol for prone positioning (5,22) .
The Risk of Pressure Injury is conceptualized as the susceptibility to skin and/or adjacent tissue injury, usually on the bony prominence due to pressure, and has as risk factors inadequate nutrition, the impossibility of changing positions due to the severe clinical condition, self-care deficit, and patients with extreme age (5) . A very high incidence was identified in the same ICU, in the period from 2012 to 2014, 42.7% (23) , much higher than that of an ICU in Vale do São Francisco, in Pernambuco, where a prevalence of 22.3% was identified and associated with the patient's origin from the emergency room and hospitalization time equal to or greater than ten days (24) . In this regard, as the incidence of the diagnosis Risk for Pressure Injury was high, it is essential that the patient with COVID-19, especially in the prone position, is provided with preventive measures as the use of cushions in areas that were not usual for prevention, such as the face, ears, knees, among others (9,22,24) . In addition, a diet focused on the patient's needs, dialoguing with the nutritionist and the physician, and risk and lesion progression assessment through specific scales, such as Braden's. Studies have revealed that malnutrition severity increases the severity and likelihood of developing pressure injuries (25) .
Another ND present is the Risk of corneal injury, which, although not statistically significant for mortality, has drawn attention to eye care in these patients (5,22,(26)(27)(28) . In a previous cohort study in Acre, in a non-COVID ICU, the incidence of corneal injury was 18.8%, which demonstrates that one out of five patients had corneal injury, which is considered a high incidence (26) .
The risk of corneal injury is very common in ICU patients due to changes in the mechanism of blinking and closing the eyelids caused by the level of consciousness lowering and the use of sedatives and muscle blockers (5,(26)(27)(28) . Nursing eye care includes eye hygiene with gauze and saline solution, lubrication of the corneas with eye drops or lubricating ointments and manual eyelid closure in case of lagophthalmos. Moreover, scientific evidence suggests that the use of a gel lubricant and a polyethylene chamber are the best evidence to prevent corneal injury in ICU patients (27)(28) .
The patients' clinical records presented little information of NDs of domains 9, 10 and 12, such as Anxiety, Fear, and Impaired Religiosity, which may also reflect the professional team's emphasis on the biomedical model, requiring further continuing education on patients' biopsychosocial assessment, which aims to understand them in their entirety (5,29) .