Topic Discussion: Outcomes of AKI in COVID-19

 As COVID19 surged the NY area, March-May 2020 is when the AKI surge happened at most northeast hospitals. Initial reports from us and others showed that the incidence of AKI was high- close to 40%. 

At that time, almost 39% of patients were still admitted. Now there are 99% discharged allowing for complete outcome analysis. Here is our data on the outcomes of AKI in AJKD when all have been discharged. 

The aim of this study was to investigate in-hospital death and kidney outcomes among hospitalized patients with COVID-19 and AKI.  We reviewed health records of 9657 patients hospitalized with #COVID-19 between March1- April 27^th, 2020, and followed up to the day of discharge/death. The data was from 13 hospitals. To investigate the impact of AKI on in-hospital death, we performed cox regression using AKI as a time-varying exposure and in-hospital death as the outcome.

In the cohort 40% of patients developed AKI (incidence rate of 38.3 per 1000 patient-days). Those who developed AKI had higher proportion with DM, heart disease, chronic kidney disease and had a more severe illness. The death rate was much higher in the AKI requiring dialysis( 6.4 times more) compared to AKI not requiring dialysis (3.4 times more) compared to no AKI. 

What matters to us is what happens to patients who survived? - how many had CKD, how many were sent on dialysis?  The big finding-- Among patients with AKI non-dialysis requiring who had survived, 74% had kidney recovery at the time of discharge. For patients with AKI-on dialysis and survived, 67% had kidney recovery at discharge. For the remainder who did not have kidney recovery, 91.7% remained on dialysis at the time of discharge.  Among those with AKI-on dialysis who survived, the presence of chronic kidney disease was the only independent risk factor associated with need for dialysis at discharge. 60 and 90 day outcomes are lacking and will be eventually useful. 

Regardless of need for dialysis or kidney recovery at discharge, hospitalized COVID-19 patients who experienced any form of AKI should be followed closely post-discharge to assess ongoing kidney function.  Our 13 hospital sites were all in metropolitan NY during the early part of the pandemic; is the major limitation.  

So in patients hospitalized with #COVID-19, those with AKI was associated with higher risk of death, particularly among those who needed dialysis. Most surviving patients with AKI had kidney recovery upon discharge.

Another recent study from a NY metro area showed similar findings in JASN.  Of 3993 hospitalized patients with COVID-19, AKI occurred in 1835 (46%) patients; 347 (19%) of the patients with AKI required dialysis. Of survivors with AKI who were discharged, 35% had not recovered to baseline kidney function by the time of discharge. An additional 36% patients who had not recovered kidney function at discharge did so on posthospital follow-up.

Finally, a research letter in CJASN showed some outcomes data from yet another NY center. Patients with AKI had higher mortality than patients without AKI (40% versus 8%).  Among the patients with AKI, 48% recovered to their baseline kidney function. Among the 52% who did not recover to their baseline kidney function, 43 received dialysis, among which 34 were dialysis dependent and 26 died (60%), and 111 did not receive dialysis, among which 80 (72%) died.  

Consult Rounds: Hyponatremia from Anti depressants

 As nephrologists we often get called on SIADH from medications. Anti depressants a class of agents that we do consider to cause hyponatremia. Which ones are more likely vs others has always been interesting to know? A study from Denmark has a detailed look into this matter. 

The odds of developing hyponatremia in one large study was the highest in clomipramine, followed by nortriptyline, citalopram, paroxetine, duloxetine, venlafaxine, sertraline and amitriptyline. It had the least odds of association with mirtazapine, mianserin and escitalopram. The development was highest in the first 2 weeks of starting treatment( with the highest incidence of hyponatremia in the first 2 weeks in citalopram and lowest in mianserin. 

So, SSRI had the most association, SNRIs had slightly lower and non adrenergic specific serotogenic antidepressants had the least association. 

Topic Discussion: Gut Microbiota and UTIs

 

A Gut Microbiota – Urinary Tract Infection Connection

It is presumed that gut bacteria are the source for urinary tract infection, but is there any proof? If so, could changing the gut microbiota impact urinary tract infection?

Lee et al. evaluated this premise in a cohort of 168 kidney transplant recipients and profiled the gut microbiota serially using 16S rRNA deep sequencing. They reported that having higher gut abundance of E. coli was a risk factor for development of E. coli. They further performed strain analysis on matched fecal-urine specimens and found that the E. coli in the urine most closely resemble the E. coli in the gut from the same patients, supporting a gut origin of UTIs .

A follow up analysis identified that the gut abundances of two commensal bacteria, Faecalibacterium and Romboutsia, are associated with a decreased risk for UTIs. 

The data suggest the possibility that manipulation of the gut microbiota could alter the balance of commensal bacteria and pathogenic bacteria and could decrease the risk of UTIs, especially in patients with recurrent UTIs. Indeed, there is some recent evidence in case reports. In a case series by Tariq et al., patients with recurrent UTIs and recurrent C. difficile infections underwent fecal microbial transplantation for recurrent C. difficile infections and had a significant decrease in the number of UTIs after fecal microbial transplantation.

Whether gut microbial-based therapies can break the cycle of recurrent UTIs is still not known. Nevertheless, these therapies could be a novel approach to treating this common problem.

Image credit: http://www.sci-news.com/biology/gut-microbiota-manipulate-our-minds-05956.html