The Science Journal of the American Association for Respiratory Care

2011 OPEN FORUM Abstracts

ELECTRICAL IMPEDANCE TOMOGRAPHY USED TO MONITOR REGIONAL VENTILATION FOR A PATIENT WITH PNEUMONIA: A CASE STUDY.

John S. Emberger1, Joel Brown1, Vinay Maheshwari1, Gerard Fulda2, John Getchell2; 1Respiratory Care, Christiana Care Health System, Newark, DE; 2Surgery, Christiana Care Health System, Newark, DE

INTRODUCTION: Electrical impedance tomography (EIT) is a new method of monitoring regional lung ventilation. Using a chest belt with 16 electrodes, a small current is applied and impedance signals are measured across the electrodes in a cyclic method. EIT generates images generally at 20 frames per second which are viewed as a live movie of regional ventilation. We conducted an IRB approved blinded study for EIT monitoring (EIT Evaluation Kit 2, Draeger Medical, Luebeck Germany) of ALI/ARDS patients. The following case is one of the patients from our study. CASE SUMMARY: A 61 year old female presented to the emergency department with severe respiratory distress. The patient was worked up for pulmonary embolism versus pneumonia. The patient failed BiPAP in the emergency department with worsening ABG results, was intubated and transferred to the MICU. It was found that the patient had community acquired left lower lobe pneumonia by chest x-ray and CT-Scan. The patient was consented for the EIT study several days after admission to the MICU. Three separate days of EIT monitoring were performed over a 6 day period. All of the EIT monitoring showed that ventilation was occuring in the right lung and only minimal ventilation in the left lung. The patient was extubated after the first 5 days on the ventilator. The patient was re-intubated 3 days after that extubation due to worsening ABG values, increased work of breathing and impending respiratory failure. The image displayed is an EIT regional image as well as the CT-Scan image the day after re-intubation. At the time of EIT monitoring, the patient was on PSV 12, PEEP 5, FiO2 40%. Exhaled tidal volumes were 400 to 500 mls with RR 11 to 15 and SpO2 of 98%. The patient remained intubated for 3 more days then was extubated successfully. The patient was discharged 5 days after extubation, to a rehabilitation facility for muscle reconditioning before returning home. DISCUSSION: In this case of left lower lobe pneumonia, EIT imaging was comparable to CT-Scan images as well as chest x-rays. EIT may be a valuable device to monitor regional lung ventilation in patients with ALI or ARDS in the future.
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EIT image showing regional ventilation and CT-Scan image on day 8 of a patient with left lower lobe pneumonia. The EIT device displayed that 84% of ventilation was in the right lung and 16% was in the left lung.