Comparing the Effect of Respiratory Physiotherapy and Positive End-Expiratory Pressure Changes on Capnography Results in Intensive Care Unit Patients with Ventilator-Associated Pneumonia.

Background: While critically ill patients experience a life-threatening illness, they commonly develop ventilator-associated pneumonia (VAP) which can increase morbidity, mortality, and healthcare costs. The present study aimed to compare the effect of respiratory physiotherapy and increased positive endexpiratory pressure (PEEP) on capnography results.

Materials and methods: This randomized control clinical trial was performed on 80 adult patients with VAP in the intensive care unit (ICU). The patients were randomized to receive either PEEP at 5 cm H₂O, followed by a moderate increase in PEEP to 10 cm H₂O, or PEEP at 5 cm H₂O with respiratory physiotherapy for 15 min. The numerical values were recorded on the capnograph at minutes 1, 5, 10, 15, and 30 in both methods. Data collection instruments included a checklist and MASIMO capnograph.

Results: As evidenced by the obtained results, the two methods significantly differed in the excreted pCO₂ (partial pressure of carbon dioxide) (P<0.0001). However, the average amount of excreted pCO₂ was higher in the respiratory physiotherapy and PEEP intervention (38.151mmHg) in comparison with increasing PEEP alone method (36.184mmHg). Also, PEEP elevation method prolonged the time of the first phase (inhalation time) and the second phase while shortening the third phase (exhalation time) in capnography waves.

Conclusion: CO₂ excretion in patients with VAP increased after respiratory physiotherapy. Further, physiotherapy demonstrated more acceptable results in CO₂ excretion compared with PEEP changes in mechanically ventilated patients.