Comparative evaluation of ventilatory function through pre and postoperative peak expiratory flow in patients submitted to elective upper abdominal surgery

Abstract

Objective: to evaluate the ventilatory function by Peak Expiratory Flow (PEF) in the immediate pre and postoperative periods of patients undergoing elective surgical procedures in the upper abdomen. Methods: we conducted a prospective cohort study including 47 patients admitted to the Hospital Regional de Mato Grosso do Sul from July to December 2014, who underwent elective surgeries of the upper abdomen, and submiited to spirometric evaluation and measurement of PEF immediately before and after surgery. Results: of the 47 patients, 22 (46.8%) were male and 25 (53.20%) female. The mean preoperative PEF was 412.1±91.7, and postoperative, 331.0±87.8, indicating significant differences between the two variables. Men had higher PEF values than women, both in the pre and postoperative periods. There was a reasonable inverse correlation between age and decreased PEF. Both situations showed statistical significance (p<0.001). The group of smokers had lower PEF values both before and after surgery. The group of patients with comorbidities (hypertension and/or diabetes) showed lower PEF values both pre and postoperatively (p=0.005). In both groups, surgery resulted in a significant decrease in PEF (p<0.001). The type of surgery performed and the type of anesthesia did not show significant differences. Conclusion: the variables most involved in decreased lung function were: advanced age, smoking and presence of comorbidities. However, there is no consistent evidence to suggest conducting routine spirometry in such patients.

Nursing outcome “airway permeability” in postoperative patients

“…Postoperatively, the peak of diaphragmatic dysfunction occurs in the period between two and eight hours after surgery, returning to preoperative values in roughly seven to ten days (5) . A study that The type of surgery performed in the patients in this study may cause changes in the diaphragmatic respiratory pattern, which usually makes breathing shallower with thoracic predominance, which may explain the alteration in the "depth of breath" indicator identified in this sample.…”

“…Respiratory changes that occur in the postoperative period can result in severe complications, affecting about 25-50% of patients undergoing major surgical procedures. The literature indicates that the surgical site is the most important factor for determination of postoperative pulmonary complications (POPC), which occur in 10-40% of the cases of patients whose surgical incision is in the upper abdomen or in the thorax (5) . A study (16) that investigated the occurrence of POPC identified that thoracic (28.9%), cardiac (28%) and upper abdominal (24.3%) surgery had the highest complication rates in the postoperative period.…”

“…The alteration in the "respiratory rate" indicator can be justified by abdominal rigidity and diagrammatic dysfunction occurring in the postoperative period, altering ventilatory mechanics and conferring restrictive characteristics, with a reduction in vital capacity and tidal volume. As a way to compensate for lower ventilatory efficacy, carbon dioxide retention and lower tidal volume, respiratory rate increases (5) .…”

“…This result corroborates research (18) performed with patients submitted to exploratory laparotomy which identified a significant increase in respiratory rate in the initial hours of the postoperative period. It should be noted that high values of respiratory rate contribute to an increase in respiratory work, since ventilation tends to be greater in places where airway resistance is smaller (5,18) . and pain interfere with the act of coughing and compromise its effectiveness, since anesthesia depresses the cough reflex and pain reduces the amount of deep inspirations due to the surgical procedure (21) .…”

“…The changes that occur in pulmonary physiology can result in respiratory complications in the postoperative period, evidenced as one of the main problems that affect patients submitted to thoracoabdominal procedures (4) . The literature indicates that pulmonary complications affect approximately 10% to 40% of these patients, and the values vary according to the presence of risk factors (5) . Therefore, because the surgical act is an agent that causes respiratory physiological changes, it is considered important to adopt strategies that aim at the reestablishment of the pulmonary function as a way to prevent respiratory complications postoperatively.…”