급성 호흡부전증으로 기계호흡중인 환자에서 예후의 조기 예측에 대한 연구 = A Study on the Early Prediction of Prognosis in Mechanically Ventilated Patients due to Acute Respiratory Failure

다국어 초록 (Multilingual Abstract)

Background: Acute respiratory failure is a condition in which an illness or impairment of the respiratory system results in inadequate oxygenation or ventilation, or both, It occurs in all age-group. The causes for acute resiratory failure are varied because it is a frequent complication of many diseases. Even though patients are managed intensively with mechanical ventilation, the mortality rate has been 20-60% until today. Therefore, early prediction of r>utcome in such patients should be considered a high priority so that corrective measures or alternative support methods may be rapidly institued. Methods: We did this study prospectively in patients who survived more than 8 days after receiving me-chasnical ventilation continuously in the Intensive Care Unit. Patients whose initial arterial blood gas values before mechanical ventilation which showed PaO2, less than 50 mmHg or PaCO2, greater than 50 mmHg were included. We divided the patients into the Survivor (n= 66) and Non-survivor (n=74) group. During the first 7 days of mechanical ventilation, we measured the FiO2, PHa, PaO2, PaCO2, Tidal volume, Respiratory rate, Peak inspiratory pressure, Plateau pressure and End expiratory pressure daily. From the collected data, the following variables were calculalted: Buffer base deviation (measured-predicted), Minute ventilation (tidal volume×respiratory rate), Dynamic compliance (tidal volume/(peak pressure-PEKP)), Static compliance (tidal volume/(plateau pressure-PEEP)), Pulmonary insufficiency index, Physiologic shunt or Gas exchange indexes such as PaO2/FiO2, and PaO2/PAO2, and our own variables such as D(A-a)O2/FiO2 and PAO2/FiO2. We compared these variables daily between the survivor and non-survivor groups. Results: Age didn't show a significant difference and ICU stays were longer in the survivor group. We didn't find any significant difference in buffer base deviation, minute ventilation, and dynamic compliance between the two groups. Static compliance showed higher values in the survivor group and from the 4th day after mechanical ventilation, there was a significant difference. Pulmonary insufficiency index and the ratio of D(A-a) O2/FiO2, and PAO2/FiO2, showed significaotly higher values in the nonsurvivor group throughout the first seven days. There was a tendency of gradual decrease in the survivor group but almost no change in the nonsur-vivor group. The ratio of PaO2/FiO2, and PaO2/PAO2, showed significantly higher values in the survivor group throughout the first seven days. There was a tendency of gradual increase in the survivor group but almost no change in the nonsurvivor group. Conclusion: Static compliance, pulmonary insufficiency index, D(A-a)O2/FiO2, PAO2/FiO2, PaO2/FiO2, and PaO2/PAO2, showed a significant difference between the survivor and nonsurvivor groups, and each value showed the characteristic changing patterns throughout the first 7 days after mechanical ventilation. With observation of each value and changing patterns during the first 7 days after mechanical ventilation, these parameters were thought to be helpful in the early prediction of outcome in mechanically ventilated patients due to acute respiratory failure.