Detection of Pleural Effusion and Monitoring Its Treatment by Internal Thoracic Impedance in Elderly Patients

Objective internal thoracic impedance (ITI) was previously shown to be a sensitive method for detecting pulmonary edema and pleural effusion at their preclinical stage. The current study describes the usefulness of this noninvasive method in geriatric patients for both detecting early pleural effusion and monitoring increased ITI during its resolution. Methods: A prospective controlled study was conducted in 2012-2013. Seventy patients over 65 years old (range 65-94 years) were recruited, of whom 39 had pleural effusion and 31 did not. ITI was continuously measured using the RS-207 monitor. The predictive value of ITI monitoring was determined by taking eight measurements every 12 hours for a total of 84 hours. Results: Following medical treatment, the median ITI of the study group rose from 31 ohms (IQR 28-33 ohms) to 41 ohms (IQR 38-41 ohms) (P < 0.001), compared to non-significant changes in the control group. Considerable changes were observed in the respiratory rate (RR) of the study group: a decrease from 29 (IQR 28-34) to 19 (IQR 18-20) (34.8%) was noted, compared to no change in the controls. Conclusion: Monitoring ITI offers an efficient tool for the diagnosis and evaluation of treatment in elderly patients with pleural effusion. Early and better treatment has the potential to prevent serious complications such as respiratory distress, intubation, and make extended hospitalization unnecessary.