Intensivists can use point-of-care echocardiography and
thoracic ultrasound (POCUS) to obtain clinically useful information that can
aid decision making in critically ill COVID-19 patients.
Accepting the Investigator of the Year 2020 award, Dr Helen
Jordan, Dual Anaesthetics and ICM Trainee at NHS Lothian, talked delegates
through her winning project.
Background
Intensive care teams face a multitude of challenges to
managing people with COVID-19, she said, not least the unknown disease
progress, and unclear management strategies and pathophysiology. Early case
reports highlighted cardiac involvement, including arrhythmias and myocarditis.
Fluid status was often uncertain, and many patients present “quite markedly”
hypovolaemic.
“Examining these patients was challenging due to having to
wear PPE, and we have limited resources due to the high number of patients
being admitted. We had to restrict the number of specialties coming into the intensive
care area, and these patients were particularly unstable and, therefore, it was
challenging to transfer them for further imaging.
“For all these reasons, there was a lot of interest in the
use of point of care ultrasound in the assessment and management of COVID-19
disease,” said Helen.
POCUS in COVID-19
Early in the pandemic, the Intensive Care Society
recommended that critical care clinicals be trained in the use of lung
ultrasound and focused echo after data emerged showing distinctive thoracic
ultrasound findings in COVID.
On ultrasound, these included pleural thickening, focal,
multi-focal, and confluent B-lines, consolidation, fewer pleural effusions than
the general ICU population. The echocardiographic features of COVID-19 include global
or regional impairment of the left ventricle (LV), right ventricular (LV) impairment
or dilatation, and signs of pulmonary hypertension and myocarditis.
Point-of-care ultrasound is already well established at NHS
Lothian, which has three critical care units which were expanded to a capacity
of 52 beds during the peak of the pandemic.
Methods
The team carried out a retrospective review of COVID-19
patients admitted between 1 April and 1 May 2020. They recorded baseline patient
demographics, the indication for the scan, the clinician’s level of training,
the principle findings, any changes in management, and the outcome data. They
also collected the ventilator settings, any evidence of arterial thrombosis,
and relevant post-mortem examination results.
Results
They found 55 transthoracic echoes performed on 35 patients,
and 32 thoracic ultrasounds performed on 22 patients.
More than half, 53%, of the echoes had been performed by a
consultant. All the clinicians had at least the Focused Intensive Care
Echocardiography (FICE) accreditation. FICE, Helen explained, is a focused exam
that seeks to answer five questions:
- Is LV significantly impaired?
- Is RV significantly impaired or dilated?
- Any pericardial fluid?
- Any evidence of hypovolaemia?
- Any pleural fluid?
Overall, 64% of scans identified an abnormality. The most
common findings were significantly dilated or impaired RV (44%), hypovolaemia
(22%), pericardial fluid (48%), and significant LV impairment (9%). Echo led to
a change in management in 71% of cases, with the most common changes being
further imaging, changes in fluid management, and changes in medication.
All ultrasounds showed lung sliding, pleural thickening and
B-lines. In total, 71%, had multi-focal B-lines, suggestive of severe COVID-19,
74% had bilateral subpleural consolidation, and 10% demonstrated pleural
effusions. Ultrasound led to a change in management, such as the initiation of neuromuscular
blockers, in 69% of cases.
The study recorded a 30-day mortality rate of 43%.
Limitations
Helen said that the results of this retrospective study of a
relatively small number of patients should be interpreted with caution. It is
possible that clinicians scanned more patients with a higher severity of
illness or who were deteriorating. This may have increased the incidence of
findings and the mortality recorded, she said.
Conclusion
POCUS can provide clinically useful information which can
aid decision making and result in changes of management in patients with
COVID-19 in intensive care, concluded Helen.
The advantages to intensive care clinicians being able to
perform focused echo and thoracic ultrasound are multiple, she said. It allows
for the rapid assessment of unstable patients with an unclear diagnosis, reduces
the need for other specialties to enter the intensive care unit, and helps to
preserve PPE. “However, it is important that intensive care clinicians
understand their limitations and have sufficient support from cardiology and
the echo department,” said Helen.
At NHS Lothian, she went on, all intensive care doctors and
advanced care clinical practitioners have been offered online training on heart,
lung, abdomen and DVT ultrasound. The echo department is also helping personnel
with mentoring and training, and several are looking to gain their BSE level
one and level two, said Helen.
BSEcho 2020 presentations are available on our website for members of the Society.
View the presentations