Feasibility and reliability of pocket-size ultrasound examinations of the pleural cavities and vena cava inferior performed by nurses in an outpatient heart failure clinic

Background: Routine assessment of volume state by ultrasound may improve follow-up of heart failure patients. Aims: We aimed to study the feasibility and reliability of focused pocket-size ultrasound examinations of the pleural cavities and the inferior vena cava performed by nurses to assess volume state at an outpatient heart failure clinic. Methods: Ultrasound examinations were performed in 62 included heart failure patients by specialized nurses with a pocket-size imaging device (PSID). Patients were then re-examined by a cardiologist with a high-end scanner for reference within 1 h. Specialized nurses were able to obtain and interpret images from both pleural cavities and the inferior vena cava and estimate the volume status in all patients. Results: Time consumption for focused ultrasound examination was median 5 min. In total 26 patients had any kind of pleural effusion (in 39 pleural cavities) by reference. The sensitivity, specificity, positive and negative predictive values were high, all 92%. The correlations with reference were high for all measurements, all r 0.79. Coefficients of variation for end-expiratory dimension of inferior vena cava and quantification of pleural effusion were 10.8% and 12.7%, respectively. Conclusions: Specialized nurses were, after a dedicated training protocol, able to obtain reliable recordings of both pleural cavities and the inferior vena cava by PSID and interpret the images in a reliable way. Implementing focused ultrasound examinations to assess volume status by nurses in an outpatient heart failure clinic may improve diagnostics, and thus improve therapy.