Respiratory status of adult patients in the postoperative period of thoracic or upper abdominal surgeries 1

ABSTRACT Objective: to evaluate the respiratory status of postoperative adult patients by assessing the nursing outcome Respiratory Status. Method: descriptive, cross-sectional study developed with 312 patients. Eighteen NOC indicators were assessed and rated using a Likert-scale questionnaire and definitions. Descriptive and correlative analysis were conducted. Results: the most compromised clinical indicators were coughing (65.5%), auscultated breath sounds (55%), and respiratory rate (51.3%). Factors associated with worse NOC ratings in specific clinical indicators were sex, age, pain, and general anesthesia. Conclusions: certain clinical indicators of respiratory status were more compromised than others in postoperative patients. Patient and context-related variables can affect the level of respiratory compromise.

Studies have been developed to test the applicability of NOC outcomes, the validity of NOC indicators, and to translate and adapt NOC outcomes to specific cultural contexts. We found studies assessing NOC outcomes in Intensive Care Unit (ICU) patients (9) , patients with cancer (10) , stroke (11) , diabetes (12) , and congenital heart diseases (13) . However, no study including operational definitions for the nursing outcome Respiratory Status and its applicability to postoperative adult patients was published to this date.
Some advantages of using NOC are the decrease in documentation time allowing more time available for patient care (14) , improved patient satisfaction (15) , reduced variability in the nursing assessment (11) , and improved quality of care by the establishment of parameters for the clinical assessment (16) . However, whenever NOC outcomes are assessed without clear conceptual and operational definitions for clinical indicators, there is uncertainty and subjectivity, which is an important gap in nursing practice. Therefore, this study aimed to evaluate the respiratory status of postoperative adult patients by assessing the nursing outcome Respiratory Status.

Method
This was a descriptive cross-sectional study. The study was performed between 2014 and 2015 in the post-surgical unit of a large tertiary hospital located in the northeastern Brazil.
The study involved 312 participants who were hospitalized for surgical treatment of different conditions or diseases. Participants were recruited and assessed during the first 48 hours after surgery, based on the following inclusion criteria: age between 18 and 80 years, and thoracic or upper abdominal surgery. Patients who were using gastric-tube feeding, tracheostomy, or had serious cognitive impairment were excluded because their condition might limit their ability to be examined during the study.
The sample size was determined by using a formula for infinite populations (n=Zα 2 .P.(1-P)/E 2 ) assuming a confidence level (Zα) of 95%, standard error (E) of 5.6%, and a prevalence (P) of respiratory nursing diagnoses at 46.7% according to a previous study (17) .
Therefore, the minimum sample size was 305 patients, but 312 patients participated in the study. were used as a basis to rate each indicator into five levels: 1 representing the highest degree of severity and 5 representing the lowest level of severity or lack of compromise. Indicators were considered compromised when they were rated below or equal

Results
Of the 312 participants (mean age 38, SD 16, range 18-78), 67.9% are male, 46.8% never were married or lived in a paired relationship, and 54% have had primary or secondary education. Table 1 show the clinical characteristics of the patients. Most patients (56.5%) had never smoked. The most frequent surgery performed was exploratory laparotomy (78.2%) and 70.6% patients underwent local or regional anesthesia.
On examination, all patients had normal vital parameters.
Findings from the assessment of the NOC outcome Respiratory Status are summarized on Table 2       Rev. Latino-Am. Enfermagem 2017;25:e2959. In addition, general anesthesia reduces lung volume and capacity, reduces chest and lung compliance, and affects the diaphragm movement. On the other hand, local and regional anesthesia do not affect the respiratory function, hence, patients who receive local anesthesia generally do not have serious postoperative complications (29) . We have no explanation to the finding that general anesthesia acted as a protection factor for the occurrence of cyanosis, but the literature shows that postoperative cyanosis is usually more related to a patient's disease or baseline condition than type of anesthesia (30) .

Discussion
Some limitations of this study must be considered.