The Science Journal of the American Association for Respiratory Care

2012 OPEN FORUM Abstracts

A CASE OF DERECRUITMENT AND RECRUITMENT OBSERVED WITH ELECTRICAL IMPEDANCE TOMOGRAPHY.

John S. Emberger1, Joel M. Brown II1, John Getchell3, Vinay Maheshwari2, Gerard Fulda3; 1Respiratory Care, Christiana Care Health System, Newark, DE; 2Medicine, Christiana Care Health System, Newark, DE; 3Surgery, Christiana Care Health System, Newark, DE

INTRODUCTION: Electrical impedance tomography (EIT) monitors regional lung ventilation via an electrode chest belt measuring impedance. EIT displays a functional tomograph image similar to a CT-scan slice of the chest which is viewed as a live video usually at 20 frames per second. We conducted an IRB approved blinded study of EIT on ALI/ARDS patients (EIT Evaluation Kit 2, Draeger Medical, Luebeck Germany). The following case was a patient in our observational study. CASE SUMMARY: A 78 year old male presented as a result of a motor vehicle crash. Patient had B/L pnuemothorax, aortic & chest contusion and pelvic fractures. Patient required a splenectomy and developed ARDS by day 3 of admission. EIT monitoring was performed on day 7 of admission after informed consent. On day 7 of admission, patient had been weaned to PSV 8 cmH2O, PEEP +5 cmH2O and FiO2=35%. Patient RR was < 20. Patient was placed on routine spontaneous breathing trial (SBT) by protocol, PSV 5 cmH2O with PEEP+5 cmH2O. After 30 minutes on the SBT, patient was noted to have RR > 30, increasing dyspnea and desaturation to 84%. Patient was increased to PSV 12 cmH2O, PEEP+12 and FiO2 50% over about 15 minutes of observation. Patient RR decreased below 20, dyspnea was relieved and SpO2 increased > 95%. The EIT device was monitoring the patient during this time, although caregivers were blinded. Observation of the EIT data by investigators revealed the derecruitment of the left posterior quadrant of the patientÂ’s lung while on the SBT and recruitment of that quadrant after settings were increased (see the figure). SBT attempts were made on subsequent days and the patient continued to have desaturation events.A tracheostomy was placed on day 17 of admission and tracheostomy trials were initiated. The ventilator was discontinued on day 34 and patient was discharged home on day 40. DISCUSSION: This case demonstrates a patient recovering from ARDS who derecruited a large portion of posterior lung area while receiving an routine SBT. Once the caregivers noticed signs of decompensation (increasing RR & dyspnea with desaturation), support was increased (PSV and PEEP). EIT demonstrated the recruitment of the posterior lung area that had derecruited on the SBT. EIT could play a future role in monitoring recruitment and derecruitment in patients at risk for derecruitment and atelectasis. Sponsored Research - None EIT images showing a cross-section of the lung fields (similar to that of a CT-scan image). A - PSV before SBT. B - Derecruitment of left posterior area while on SBT with dyspnea and desaturation. C - Recruitment of left posterior lung area on PSV 12 and PEEP+12