2009 OPEN FORUM Abstracts
ELECTRICAL ACTIVITY OF THE DIAPHRAGM DURING EXTUBATION READINESS TESTING IN THE PEDIATRIC PATIENT
Brian K. Walsh1,2, Gerhard Wolf2, Michael Green2, John Arnold2,1; 1Respiratory Care, Children’s Hospital Boston, Boston, MA; 2Critical Care, Children’s Hospital Boston, Boston, MA
Introduction: Diaphragmatic function plays an important role in respiration and the patient’s ability to coordinate with and liberate from mechanical ventilation. Diaphragmatic fatigue or ventilator induced diaphragm dysfunction may be primarily responsible for weaning or extubation failures. Investigators have proposed several strategies that attempt to predict extubation success, but none have been shown to be superior to individual expert clinical judgment. The present study was designed to characterize the electrical activity of the diaphragm during extubation readiness testing (ERT). Understanding whether diaphragmatic function is a predictor of extubation readiness or extubation failure could add substantial knowledge to the field of weaning pediatric patients with acute lung injury. Methods: All intubated and mechanically ventilated patients who are eligible for ERT between the age of one day and 18 years were considered eligible for this study. An ERT is a weaning challenge conducted on most patients without a cardiac or chronic respiratory disorders (neuromuscular, CF, etc,). In short, this test is conducted once the patient has plateau in their ventilation course (FIO2 < 0.5 and PEEP < 8) and is spontaneously breathing. They are switched to minimum PSV with a pressure set according to their ETT size and tested for a maximum of 2 hours. A pass or fail judgement is assigned based on objective measurements by the RT. All Edi, ventilatory parameters and spirometry measurements were recorded with the Servo-i ventilator. Prior to the ERT, a size appropriate multiple-array esophageal electrode (Edi catheter)was placed according to the manufacturer’s recommendations and the ICU protocol. Four Edi measurements were taken. One measurement was recorded prior to the initiation of the ERT (Pre), one at an hour (H1) following the start of the ERT, one at two hours (H2) and one 30 minutes following extubation (Post) or return to prior mechanical ventilation support. Preliminary Results: 16 patients were enrolled from age 1 week to 17 years of age. See figure 1 for details of Edi during ERT. See figure 2 for details of Edi following extubation. Conclusion: Patients who passed the ERT increased their Edi from baseline more than those who failed did. The lack of response in electrical activity of the diaphragm may be attributed to over sedation. Interesting enough Edi may be an indication of extubation failure as well. Sponsored Research - Maquet provided Edi monitoring supplies used in this research project.