Jurnal Internasional Afrika vol.10 issue.3 2020
African Journal of Emergency Medicine
Could lung ultrasound be used instead of auscultation?

Jurnal Internasional Afrika vol.10 issue.3 2020
African Journal of Emergency Medicine
Could lung ultrasound be used instead of auscultation?

The covid-19 era poses significant and unprecedented challenges for
re-organisation of care, redistribution of resources and rationing of
services

The covid-19 era poses significant and unprecedented challenges for
re-organisation of care, redistribution of resources and rationing of
services [1,2]. A review of patients' clinical characteristics showed a
high prevalence of respiratory symptoms and respiratory failure which
require full assessment [3]. However, the role for auscultation is not
proven and may be a very risky strategy as the risk of cross infection
with taking a stethoscope from a patient to the next is very tangible
[4,5]. A recent editorial in the African Journal of Emergency medicine

suggested Severity Scoring Tool for low resourced settings and men-
tioned auscultation [6].

The stethoscope and auscultation have limited usefulness in the

assessment of respiratory failure. Crackles on auscultation have a sen-
sitivity of 19–67% and a specificity of 36–96%, with a positive like-
lihood ratio of 2.3 and a negative likelihood ration of 0.8 [7]. Thus,

their use in ruling pneumonia in or out is limited as their presence or
absence only slightly changes the initial diagnosis (poor inter observer
reliability, 72% agreement, kappa value 0.41) [7]. One might argue on
the value of detecting wheeze on auscultation. The Centers for Disease
Control and Prevention (CDC) does not mention wheeze as a symptom
of Covid-19 [8]. Furthermore, Xu et al. did not describe wheeze as a
finding in 62 patients with Covid-19 [9] and as such wheeze does not
seem to be present in such patients.
Hence, in the current pandemic, is there a role for other diagnostic
or investigative modalities such as lung ultrasound?

Lung ultrasonography in acute respiratory failure has been de-
scribed for over a decade. A 2008 single centre study of bedside lung

ultrasound examination protocol showed an accuracy of 90.5% in di-
agnosing the cause of acute respiratory failure in critically ill patients.

The methods were standardised and reproducible [8]. This has been
since incorporated in consensus guidelines [10]. As such, it has been
debated as to whether lung ultrasound can have a role to play in the
diagnostic pathway for Covid-19. Point of care ultrasound machines can
be small, portable and cleaned in between patients [11,12]. Huang
et al. performed lung ultrasound on 19 non-critical Covid-19 patients
and found them to have specific characteristics (large number of B lines,
subpleural pulmonary consolidation and poor blood flow) which were
mainly visible in the posterior and inferior areas [13]. Ultrasound
missed lesions that were completely intrapulmonary and apical and
some of the analysis is only in abstract form. Care must be applied to
the analysis of this as this is a pre-print, and not peer-reviewed. Peng
et al. found similar findings using a similar 12 zone method but the
article lacks details about the clinical characteristics of the patients

[14]. Poggiali et al. found strong correlation between similar ultra-
sound findings and strong correlation between ultrasound and CT scan

findings [15].

Commentary

https://doi.org/10.1016/j.afjem.2020.04.007

26 April 2020

peri irawan

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