The Science Journal of the American Association for Respiratory Care

2011 OPEN FORUM Abstracts

FEASIBILITY OF ELECTRICAL IMPEDANCE TOMOGRAPHY (EIT) FOR BEDSIDE PATIENT USE.

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

BACKGROUND: EIT is a lung function monitoring technique using electrodes conducting impedance measurements. Changes in ventilation cause changes of impedance which can be displayed as cross-sectional images representing regional distribution of ventilation. EIT had not been feasible due to the process of securing many electrodes to the chest. A device (EIT Evaluation Kit 2, Draeger Medical, Luebeck Germany) using an elastic electrode belt may make bedside EIT feasible. We conducted an IRB approved feasibility study of EIT. METHOD: EIT was conducted on consented patients up to 6 hours/day over three days. Researchers observed and stored EIT data on the device. Caregivers were blinded to EIT data and EIT was not used to guide patient care. A properly sized electrode belt was placed on each patient during routine re-positioning. There are 5 different sized belts. Feasibility was observed including ease of placing the belt and initiating EIT monitoring. Issues affecting the ability to maintain EIT monitoring were observed. RESULTS: 13 patients were monitored with EIT (8 females). 27 days total of EIT monitoring were performed. Consent was not sought on 2 potential patients due to chest tube dressings covering EIT belt location. Consent was not sought on 1 potential patient due to pacemaker. 2 patients were monitored despite chest tube dressings. 2 patients were monitored with body weight > 300 pounds. Electrode belt placement was completed in less than 10 minutes. The belt was functional without electrode gel, however gel was used on 3 patients who had subjectively dry skin. EIT monitoring was always initiated in less than 20 minutes from entering the room. EIT required restart/re-zeroing on 5 patients periodically during the monitoring period. This was required due to vibration of the electrodes; vibrating (percussion) bed and patient agitation. Awake and alert patients were successfully monitored if not agitated. No skin breakdown/irritation occurred. Chest hair and breast tissue was not noted as affecting the EIT monitoring. CONCLUSION: EIT monitoring is feasible and can be quickly initiated at bedside with the use of a new elastic electrode belt depending on the following factors: 1)skin is intact and not covered with a dressing 2) patient is not agitated or being percussed 3) patient fits the electrode belt - EIT was successful in patients greater than 300 pounds. EIT is feasible and may be a valuable tool for monitoring regional lung ventilation.
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Manikin with EIT Chest Belt