Topic Discussion: Electrolytes Disorders with COVID19

AKI has been reported with COVID19 ,electrolyte disorders have been less well described. A recent paper in CKJ describe the full spectrum of electrolyte disorders seen with COVID19.

The most common presentation was hyponatremia and hypochloremia together (second vertical bar) in 1289 (12.4%), followed by hyponatremia alone (third vertical bar) in 1150 (11.1%).

What about patients with eGFR<60 but >15? 30.3% had hyponatremia, 11.1% had hyperkalemia, and 19.7% had hypochloremia. Hypocalcemia was seen in 19.2% of patients. Hyperphosphatemia (13.9%) and hypermagnesemia (12.2%) were seen in fewer patients.

What about ESKD patients?

In these patients the most common disorders were hypochloremia (62%), hyponatremia (40.9%), and hyperkalemia (23.4%). Hyperphosphatemia was seen in 45.7% of patients but we had some missing phosphorus data.

What about kidney transplant recipients? The most commonly seen were hyponatremia (42.4%), hyperkalemia (16.7%), and hypochloremia (19%).

Limitations: Purely descriptive.

But highlights for the first time and the largest to date on the various electrolyte disorders in hospitalized COVID-19 patients. Further studies are needed to look at mortality outcomes related specifically to each electrolyte disorder.

Prevalence of Hyponatremia related to COVID19 has been described in the NY region. Looking at the spectrum of both hyponatremia and hypernatremia and it's relation to patient outcomes has not been well studied.

To take this further, Na disorders were evaluated in detail with outcome of mortality. This is published in NDT. Among 9946 patients included in the study ,4808 (48.3%) had normonatremia, 3532 (35.5%) had mild hyponatremia, 904 (9.1%) had moderate/severe hyponatremia, 319 (3.2%) had mild hypernatremia, and 383 (3.8%) had moderate/severe hypernatremia. When examined by decile of age, dysnatremia occurred in 46-54% of patients in each group, with hyponatremia the predominant disorder across all age groups. The proportion of patients who experienced in-hospital death was highest for those with moderate/severe hypernatremia (232/383 [60.6%]), followed by mild hypernatremia (163/319 [51.1%]), moderate/severe hyponatremia (261/904 [28.9%]), mild hyponatremia (818/3532 [23.2%]) and normonatremia (1089/4808 [22.6%]), a trend seen across all age groups. 

U-shaped pattern was seen in the relationship between admission serum sodium level and the odds of in-hospital death, with hyponatremia and hypernatremia both significantly associated with mortality, even after full adjustment for demographics, comorbid conditions and illness severity. Compared to hyponatremia, hypernatremia carried a strong association with in-hospital death, in both mild and moderate/severe categories, and across all ages, a relationship that persisted even following correction for serum glucose. While hypernatremia has  been shown to be  a strong predictor of mortality in prior studies, this finding is novel for COVID-19. 

Both hyponatremia and hypernatremia were also associated with a prolonged hospital length of stay. The magnitude of the odds ratio was substantial, especially for moderate/severe hypo- and hypernatremia, and was not substantively changed after multivariable adjustment. This suggests that at least a portion of the prolonged hospitalization may be directly related to electrolyte disorder management. 

This is the largest study to describe prevalence and outcomes of both hyponatremia and hypernatremia in a diverse population of almost 10,000 patients hospitalized with COVID-19. Other similar studies just published in the endocrine literature as well.