The Acutely Dyspneic Patient: Assessment with Serial Ultrasound

Research output: ThesisPh.D. thesis

Abstract

BACKGROUND

Acute dyspnea is a common cause of emergency department (ED) visits. Dyspnea is a subjectivefeeling that triggers substantial patient distress, and patient-reported severity of dyspnea is anessential marker for both the patient and the physician.Acute decision-making is grounded on the patient’s symptoms, medical history, and objective findings and in the subsequent follow-up of the patient on knowledge about diagnosis andprognosis. In recent years, cardiopulmonary point-of-care ultrasound (PoCUS) has been usedupfront as an adjunct to the standard care to evaluate acute dyspneic patients as part of thediagnostic process. However, the subsequent monitoring is only based on clinical assessment,early warning scores, and laboratory values. Serial cardiopulmonary PoCUS could offer an opportunity for improving monitoring owning to the dynamic nature of several ultrasound findingsthrough which treatment could be tailored. Nevertheless, the current evidence from randomizedtrials with dyspneic patients is scarce.

OBJECTIVES

1. To investigate the associations of symptoms with discharge diagnoses and mortality in a cohort of adult acute non-trauma patients arriving at a hospital in Denmark (study I).

2. To critically appraise the literature on monitoring the acutely dyspneic patient with treatment guided by serial cardiopulmonary PoCUS compared with the usual care to investigate how serial ultrasound findings are related to the prognosis, severity of dyspnea, and vital signs (study II).

3. To examine if serial cardiopulmonary PoCUS-guided treatment together with usual care of acute dyspneic patients admitted to the ED could reduce the severity of dyspnea compared with usual care alone (study III).

METHODS

Study I was a population-based, multicenter cohort study of all adult acute non-trauma patients arriving at a hospital in a region in Denmark over a 2-year period. The confounder-adjusted association between symptoms and mortality was analyzed with logistic regression. Study II was a systematic review with a search on several databases, including the grey literature, databases for ongoing trials, and reference and citation searching. The risk of bias was evaluated using Joanna Briggs Institute’s tools, and the overall strength of the evidence was appraised using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) method. In study III, a randomized, controlled, open-label, blinded-outcome trial was conducted with patients aged ≥18 years who were admitted with a primary complaint of dyspnea in an ED in Denmark. Within one hour from arrival, the patients were allocated 1:1 using block randomization to either the standard care, including a single initial cardiopulmonary PoCUS (control group), or the standard care also with an initial PoCUS plus two additional PoCUS scans performed with a 2-hour interval (serial ultrasound group). The primary outcome was a reduction of dyspnea on a verbal dyspnea scale (VDS) from 0 to 10, where 10 was worst, registered at inclusion and after two, four, and five hours.

RESULTS

In study I, 223,612 acute contacts were included with a median age of 64 years and an even sex distribution. The primary symptoms at ED arrival were unspecific (19%), abdominal pain (16%), dyspnea (12%), fever (8%), chest pain (8%), and neurologic complaints (7%). The discharge diagnosis was symptom-based (24%), observational (17%), circulatory (12%), or respiratory (12%). The 30-day mortality rate was 3.5%, with 0–7-day mortality rate of 1.7% and 8–30-day mortality rate of 1.8%. The presenting symptom was associated with the 0–7-days mortality but not with 8–30-day mortality. Across the different primary symptoms, the dyspneic patients had the highest 0–7-days mortality (adjusted odds ratio [aOR] 2.4). Age (aOR 24.0 to 42.7) and comorbidity (aOR 1.9 to 2.8) were the most predictive factors for 0–7- and 8–30-day mortality. In study II, 24 studies that included a total of 2,040 patients were selected for data extraction. Most studies were single-center and had small study populations that included only patients with acute heart failure (AHF). The risk of bias was high. None of the studies evaluated how serial PoCUS was correlated with the outcomes or provided information about treatment. In study III, 102 patients were recruited for the serial ultrasound group; and 104 for the control group. The mean difference in VDS score between the patients in the serial ultrasound and the control group was –1.09 (95% confidence interval [CI] –1.51 to –0.66) after four hours and –1.66 (95% CI –2.09 to –1.23) after five hours. A higher dose of diuretics was administered to the patients in the serial ultrasound group than to those in the control group. The difference in VDS score was even more pronounced in a subgroup of patients with AHF.

CONCLUSIONS


The most common complaints upon hospital arrival were unspecific symptoms, abdominal pain, and dyspnea. The primary complaint at hospital arrival was associated with 0–7-mortality, but age and comorbidity were the most predictive factors in 0–7- and 8–30-day mortality. Therefore, future research and development of triage and track-and-trigger systems should consider incorporating these patient-related factors to improve clinical outcomes and guide physicians in the management of patient flow in the ED. No knowledge currently exists about serial cardiopulmonary PoCUS-guided treatment. However, the evidence from the systematic review provided the foundation for designing the first randomized controlled trial to determine the association between treatment guided by serial PoCUS and patient-reported dyspnea. The study showed that the clinical effect of serial PoCUS was a reduction in dyspnea severity, especially in patients with fluid accumulation in the lungs, for whom diuretic administration could be tailored to the trajectories of the ultrasound findings. Serial PoCUS could be an add-on to the usual acute patient care in the initial diagnostics and subsequent follow-up to aid the physician in stabilizing the patient. 
Translated title of the contributionDen akutte patient med åndenød: Vurdering med seriel ultralyd
Original languageEnglish
Awarding Institution
  • University of Southern Denmark
Supervisors/Advisors
  • Lassen, Annmarie Touborg, Principal supervisor
  • Laursen, Christian Borbjerg, Co-supervisor
  • Gæde, Peter Haulund, Co-supervisor
Date of defence13. Oct 2022
Publisher
DOIs
Publication statusPublished - 20. Sept 2022

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