Clinical characteristics, risk factors and complications of COVID-19 among critically ill older adults – A case control study

Background: The older population is often disproportionately and adversely
affected during humanitarian emergencies, as has also been seen during the
COVID-19 pandemic. Data regarding COVID-19 in older adults is usually
over-generalised and does not delve into details of the clinical
characteristics in them. This study was conducted to analyse clinical and
laboratory characteristics, risk factors, and complications of COVID-19
between older adults who survived and those who did not. Methods: We
conducted a case-control study among older adults(age > 60 years)
admitted to the Intensive Care Unit(ICU) during the COVID-19
pandemic. The non-survivors (cases) were matched with age and
sex-matched survivors (control) in a ratio of 1: 3. The data regarding
socio-demographics, clinical characteristics, complications, treatment,
laboratory data, and outcomes were analysed. Results: The most common
signs and symptoms observed were fever (cases vs controls) (68.92 vs.
68.8%), followed by shortness of breath (62.2% Vs. 52.2%), and cough
(47.3% Vs. 60.2%). Our analysis found no association between the presence
of any of the comorbidities and mortality. At admission, laboratory
markers such as LDH(Lactate Dehydrogenase), WBC(White Blood Count),
creatinine, CRP(C-Reactive Protein), D-dimer, ferritin, and
IL-6(Interleukin-6) were found to be significantly higher among the cases
than among the controls. Complications such as development of seizure,
bacteremia, acute renal injury, respiratory failure, and septic shock were
seen to have a significant association with non-survivors. Conclusions:
Hypoxia, tachycardia, and tachypnoea at presentation were associated with
higher mortality. The older adults in this study mostly presented with the
typical clinical features of COVID-19 pneumonia. The presence of comorbid
illnesses among them did not affect mortality. Higher death was seen among
those with higher levels of CRP, LDH, D-dimer, and ferritin; and with
lower lymphocyte counts.