Introduction
The outcomes of patients with underlying Chronic Kidney Disease (CKD )infected with COVID-19 are relatively poorly understood. We aimed to explore this area as well as the outcomes associated with CKD in combination with other common co-morbidities.
Methods
Data was retrospectively collected on 487 adult inpatients infected with COVID-19 (positive PCR) between April and June 2020. The data collected from electronic records included baseline, peak and discharge serum creatinines and eGFR, stage of CKD, presence of renal replacement therapy, demographics and co-morbidities. An Excel spreadsheet was used to analyse data for means and standard deviations.
Results
There were 487 patients in total. The mean age was 71.9 (+-16.9) years. Of these patients 102 (20.9%) had CKD3-5 including 6 on long term dialysis, the mean age of CKD3-5 patients was 80.6 (+-10.9) years.
For CKD patients the mean eGFR at baseline, admission, nadir and discharge was 43.8 (+-11.4), 34.9 (+-16.0), 28.4 (+- 13.9) and 37.6 (+-17.3) ml/min/1.73m2 respectively. For CKD3 the mean eGFR at baseline, admission, nadir and discharge was 47.2 (+- 8.6), 32.8 (+-14.5), 31.1 (+-13.2), and 40.1 (+-15.6) ml/min/1.73m2 . For CKD4 the mean eGFR at baseline, admission, nadir and discharge were 25.1 (+-3.6), 15.3 (+-7.2), 13.7 (+-6.6) and 24.0 (+-20.0) ml/min/1.73m2 respectively. All patients with CKD5 at presentation were already on dialysis. Of the patients 81/487 (16.6%) had CKD 3, 15/487 (3.1%) had CKD 4, and 6/487 (1.2%) had CKD5 (5 with haemodialysis and 1 with peritoneal dialysis).
The mortality rate of CKD patients was 60/102 (58.8%). Mortality rates for CKD 3 was 47/81 (58.0%), for CKD 4 11/15 (73.3%) and for CKD5 2/6 (33.3%). This compared to mortality rates of 106/385 (27.5%) for patients who did not have Chronic Kidney Disease. The data set included 3 patients with functioning renal grafts. 2/3 (66.7%) had chronic kidney disease (as defined by eGFR). The mortality rate for those with renal grafts was 1/3 (33.3%).
In CKD patients (dialysis patients excluded) 60/96 (62.5%) were discharged (or died) without significant deterioration in their baseline creatinine or a “recovered creatinine” (defined as in increase of <1.25x baseline creatinine). For CKD 3 this number was 52/81 (64.2%) and for CKD4 patients this was 8/15 (53.3%). For patients with CKD who recovered their creatinine the mortality rate was 27/60 (45%) , for those who did recover it was 31/36 (86.1%)
Of the CKD patients 2/106 (1.9%) required acute haemofiltration. The mortality rate for these patients was 1 /2 (50%). However, 2/2 (100%) of these patients had recovered renal function at discharge or death.
We compared the mortality rate associated with CKD with other common co-morbidities such as dementia, Chronic Respiratory disorders (COPD/Fibrosis/Asthma), Hypertension, Diabetes and Malignancy. We also compared mortality rates for patients with CKD who had other concurrent co-morbidities; See table below:
Conclusions
Patients with Chronic Kidney Disease had a poor prognosis, worse than that associated with other common co-comorbidities. Patients with CKD4 had a worse prognosis than those with CKD3. Deterioration of eGFR during admission was associated with higher mortality rates.
No conflict of interest