Adding point of care ultrasound to assess volume status in heart failure patients in a nurse-led outpatient clinic. A randomised study

Abstract

Objectives: Medical history, physical examination and laboratory testing are not optimal for the assessment of volume status in heart failure (HF) patients. We aimed to study the clinical influence of focused ultrasound of the pleural cavities and inferior vena cava (IVC) performed by specialised nurses to assess volume status in HF patients at an outpatient clinic.

Methods: HF outpatients were prospectively included and underwent laboratory testing, history recording and clinical examination by two nurses with and without an ultrasound examination of the pleural cavities and IVC using a pocket-size imaging device, in random order. Each nurse worked in a team with a cardiologist. The influence of the different diagnostic tests on diuretic dosing was assessed descriptively and in linear regression analyses.

Results: Sixty-two patients were included and 119 examinations were performed. Mean±SD age was 74±12 years, EF was 34±14%, and N-terminal pro-brain natriuretic peptide (NT-proBNP) value was 3761±3072 ng/L. Dosing of diuretics differed between the teams in 31 out of 119 consultations. Weight change and volume status assessed clinically with and without ultrasound predicted dose adjustment of diuretics at follow-up (p<0.05). Change of oedema, NT-proBNP, creatinine, and symptoms did not (p≥0.10). In adjusted analyses, only volume status based on ultrasound predicted dose adjustments of diuretics at first visit and follow-up (all ultrasound p≤0.01, all other p≥0.2).

Conclusions: Ultrasound examinations of the pleural cavities and IVC by nurses may improve diagnostics and patient care in HF patients at an outpatient clinic, but more studies are needed to determine whether these examinations have an impact on clinical outcomes.

Trial registration number: NCT01794715.

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Figures

Figure 1

Flow chart of the study. All participants underwent full cross-over with examinations with and without ultrasound (US) in a random order at every study visit. The sequence was randomised by draw both at first and follow-up study visits. Echocardiography for validation was only performed at first visit (N=62). Both the teams with and without access to US made therapeutic decisions based on all available information (usual care±US examination). N, number of visits; NYHA, New York Heart Association; US(−), without access to ultrasound; US(+), with access to ultrasound.

Figure 2

Correlation of ultrasound indices to assess volume status by nurses with reference. The figure shows correlation of: (A) quantification of pleural effusion measured as the dimension of fluid between the diaphragm and the lung surface with patients in sitting position; and (B) end-expiratory dimension of the inferior vena cava (IVC) by pocket-size imaging device (PSID) examinations performed by nurses plotted against similar measurements by reference echocardiography. In (A) no effusion measured by both the nurse and reference is shown as the dot at 0; 0 and the dot at 0.5; 0.5 refers to effusion in the costodiaphragmatic recess only measured by both users.