By Denise Baez
There is a high prevalence of hypokalaemia among patients with coronavirus disease 2019 (COVID-19) pneumonia, and is associated with disease severity and the need for invasive mechanical ventilation, according to a study published in the International Journal of Infectious Diseases.
When analysing data from 306 patients admitted with COVID-19 pneumonia between March 3 and May 2, 2020, Oscar Moreno-Pérez, MD, Alicante General University Hospital, Alicante, Spain, and colleagues found that 94 (30.7%) had hypokalaemia — defined as nadir levels of K + ≤3.5 mmol/L — within the first 72 hours of admission.
Of the 212 patients with normokalaemia, 9% required admission to the intensive care unit (ICU), compared with 30.3% of the 76 patients with mild hypokalaemia and 33.3% of the 18 patients with severe hypokalaemia. Need for invasive mechanical ventilation was 6.2%, 25%, and 33.3%, respectively.
After adjusting for confounders, hypokalaemia was independently associated with requiring invasive mechanical ventilation during admission (odds ratio = 8.98; 95% confidence interval, 2.54-31.74).
Hypokalaemia was not associated with increased mortality, but was associated with longer hospital and ICU stay. Mortality rates were 16.2% in the normokalaemia group, 15.8% in the mild hypokalaemia group, and 16.7% in the severe hypokalaemia group. Median time in the hospital was 7 days for patients with normokalaemia, 11 days for patients with mild hypokalaemia, and 16.5 days for patients with severe hypokalaemia. Median length of time in the ICU was 8 days, 11 days, and 15 days, respectively.
The median age of the patients was 65.0 years, 57.8% males, and 53.3% had a Charlson comorbidity index score ≥3. The most common comorbidities were hypertension (46.2%), obesity (38.8%), and diabetes (21.1%). Patients with hypokalaemia had significantly higher comorbidity rates, CURB65 Severity Score for Community-Acquired Pneumonia, and serum levels of ferritin, interleukin-6, D-dimer, troponin-T, and brain natriuretic peptide. Patients with hypokalaemia and severe hypokalaemia also had a lower frequency of dry cough at the time of hospitalisation.
Therapeutic approaches initiated at admission, including use of corticosteroids and loop diuretics, did not influence the prevalence of hypokalaemia.
“This sensitive biomarker may reflect the progression of COVID-19, it is independently associated with intensive mechanical ventilation requirement after adjusting by confounders, and should be closely monitored to guide timely treatment,” the authors wrote. “Considering the implications of serum K+ concentrations in this disease, further investigation is necessary.”