Clinical Overview of COVID-19
The current WHO suspected case definition is shown in Box 1. Clinical manifestations are summarised in Box 2. Cohort studies of patients with mild and moderate disease showed that fever was the most common symptom in 82–87% of cases, followed by cough in 36–66%. This reflects findings from a meta-analysis of cases in China where, of note, fever was more common during admission than at presentation. In the RADAR COVID-19 study, in patients in a community setting with symptoms that warranted testing, anosmia was present in 59% who tested positive. Other clinical features include headache, rhinorrhoea, gastrointestinal symptoms, sore throat and fatigue. Cardiac complications are described, including myocarditis, pericardial effusion on imaging and arrhythmia, which are seen more commonly in those with greater disease severity. Patients with severe infection can develop a pro-inflammatory cytokine release syndrome, which can lead to rapid deterioration and death. The majority of studies to date have notably reported symptoms occurring in patients with proven infection in hospitals.
Early reports substantiate that older people with COVID-19 will likely present atypically; experience in France suggests that this group may initially present with delirium, postural instability or diarrhoea, rather than with typical respiratory symptoms and fever. With COVID-19 being detected in older people who are in hospital for other illnesses, such as following a fall, it remains to be determined as to what extent these index events are precipitated by COVID-19 infection versus COVID-19 being found incidentally. Atypical presentations omitted from public health campaigns, such as diarrhoea, showed a pooled incidence rate of 9.2%. Limited data are available on rates of delirium in COVID-19 infection, although the risk has been identified by the WHO and the British Geriatrics Society (BGS) who have produced specific guidelines to support delirium management in this context (Box 3).
Typical findings on blood tests are lymphopenia and elevated C-reactive protein (CRP). In moderate-to-severe cases, increased procalcitonin levels have been observed. Consistent with the aforementioned cardiac complications, severe cases often see raised levels of troponin I, D-dimer and lactate dehydrogenase.[3,10,17,25] Chest radiograph (CXR) features are 'foci' of ill-defined 'opacification' with bibasal predilection, evolving to consolidation.[7,10] On chest computed tomography (CT), typical chest findings include lower lobe and peripheral predominance with multiple, bilateral foci of ground glass opacity[6,7,12] with or without crazy paving, peripheral consolidation, air bronchograms and reverse halo or perilobular pattern. Importantly, radiological changes may be absent in early disease (56% of 36 patients scanned between 0 and 2 days of symptom onset had a normal CT) and minimal in mild disease (18% of 877 patients with non-severe disease clinically had no radiological abnormality). In severe cases, only 3% had no radiological signs. In light of this, COVID-19 cannot necessarily be ruled out on the basis of a normal CT while there is some evidence to suggest that the negative predictive value of CT is higher when symptom duration is >1 week.[26–28]
The main complication of COVID-19 is acute respiratory distress syndrome (ARDS). This is reported to occur in between 15% and 23% of cases. Other complications include respiratory failure, acute kidney injury[29,30] and liver dysfunction. Described causes of death include pneumonia, multi-organ failure and severe acute respiratory syndrome.[3,10]
There is a striking paucity of peer-reviewed evidence that examines the specific characteristics of COVID-19 in older people. Nonetheless, guidance relating to the care of older people is emerging from the international community. This guidance spans ethical considerations to the clinical management of COVID-19 in different settings with a holistic assessment in their guidance on critical care in patients aged over 65 years. The French Society of Geriatrics and Gerontology (SFGG) has highlighted the non-specific presentation of COVID-19 illness in older people. A joint consensus has been collated between the British Geriatrics Society, European Delirium Association and the Faculty of Old Age Psychiatry at the Royal College of Psychiatrists on managing delirium in suspected and confirmed cases. Specific guidelines from the United States have been published for emergency department providers usefully outlining that immunosuppression in older adults, and or the presence of comorbidities, should prompt a lower threshold for COVID-19 testing. In addition, this guidance highlights the additional challenge of communicating with people with cognitive and sensory impairments while personal protective equipment is being worn.
Age Ageing. 2020;49(4):501-515. © 2020 Oxford University Press
Copyright 2007 British Geriatrics Society. Published by Oxford University Press. All rights reserved.