Revisiting the Role of Hydrocortisone, Fludrocortisone in Septic Shock

Aaron B. Holley, MD


November 20, 2023

Earlier this year, I stumbled across a podcast in a content update email from the Journal of the American Medical Association (JAMA). The moderator was interviewing the first author of a study comparing hydrocortisone and fludrocortisone (hydro/fludro) to hydrocortisone alone for treatment of septic shock. In the introduction, the author commented on the discordance in practice among his peers at his hospital. It seemed that there was no consensus on whether fludrocortisone was necessary.

I thought this issue had been settled with publication of the COIITSS trial in 2010. This study randomly assigned 509 patients with septic shock to hydro/fludro vs hydrocortisone alone. There was a nonsignificant reduction in mortality with hydro/fludro and everyone I knew stopped adding fludrocortisone for septic shock. It wasn't included in guidelines (and still isn't). I figured the only docs still using it were also prescribing ivermectin and vitamin C - another treatment touted to work in an apocryphal podcast.

It wasn't just COIITSS that killed fludrocortisone for me. Back in 2002, I was a loyal adherent. That year, a randomized controlled trial (RCT) published by "the lord of corticosteroids for critical illness" doctor, Djillali Annane, found benefit to hydro/fludro in septic shock. Everyone in that study had a cosyntropin stim test and only certain subgroups had better outcomes. As a medical resident paying obeisance to all things evidence-based medicine, I rigidly adopted their protocol for all septic patients. I also kept their insulin between 80 and 110 mg/dL, prescribed drotrecogin alfa, and made sure they were floating in crystalloid. But those are topics for another time.

Subsequent trials and meta-analyses cast doubt on the need for the stim test, and a consensus around hydrocortisone at moderate doses for patients with septic shock emerged. Because one part of the Annane protocol was already deemed unnecessary (the cosyntropin stim test), it was easy to dismiss fludrocortisone after COIITTS was published. Yes, I read Annane's 2018 APROCCHSS trial and I'm aware that it found that hydro/fludro reduced 90-day mortality. Like others, I rationalized this finding by framing it as a function of baseline mortality. The two Annane RCTs that found that hydro/fludro reduced mortality in enrolled patients who were considerably more likely to die than those enrolled in RCTs of hydrocortisone alone were negative. It was the target population mortality rate and not the addition of fludrocortisone that made the difference, right?

Rethinking Hydro/Fludro

The author interviewed for the recent JAMA podcast forced me to rethink my blithe dismissal of fludrocortisone. He contended that the COIITTS trial was underpowered and the two Annane RCTs that used fludrocortisone supply the evidence that shows corticosteroids reduce septic shock mortality. As discussed earlier, he found clinical equipoise among his colleagues. Last, he invoked pleiotropic mineralocorticoid effects, such as activation of innate immunity and clearance of alveolar fluid, to support the need to reexamine hydro/fludro.

In his study, he used big data to compare hospital records from 2016-2020. He analyzed a total of 88,275 patients with septic shock. Most were prescribed hydrocortisone alone (85,995 [97.4%] vs only 2.6% hydro/fludro). After a number of statistical adjustments and sensitivity analyses, the authors concluded that the addition of fludrocortisone to hydrocortisone for patients with septic shock provides a 3.7% absolute risk reduction in mortality (or discharge to hospice) when compared with hydrocortisone alone. That's a number needed to treat of 28 to prevent one death (or discharge to hospice).

Key Takeaways

The study isn't perfect. In their methods section they use terms like "ensemble machine learner (super learner)" and "immortal time bias." The first is a fancy way of saying they did a form of propensity scoring, which in turn is a fancy way of saying they tried to control for confounding. The second is a way to adjust for time delays between drug administration. Both are attempts to compensate for the observational design, as is their argument for biologic plausibility. Here they're on particularly thin ice when trying to prove causal inference. Biologic plausibility is never hard to find; after all, what compound doesn't have pleiotropic effects? Furthermore, the analysis lacks any data to support their biologic plausibility hypothesis that fludrocortisone's effect on mortality is mediated via activation of innate immunity and/or clearance of alveolar fluid.

The editorial accompanying this big data study endorsed adding fludrocortisone. We have very little that reduces ICU mortality so the low number needed to treat is enticing, especially in light of the low risk from adverse events, so I'm going to start using it. Do I think I'll save one life for every 28 patients with septic shock to whom I give hydro/fludro instead of hydrocortisone alone? I sure don't. No way an oral mineralocorticoid at that dose has that type of impact on top of hydrocortisone alone. I still believe that the Annane studies are positive because of the mortality rate in the population enrolled and not because fludrocortisone was added. It all comes full circle, though - 20 years after I abandoned hydro/fludro, I'm going back to it.

Aaron B. Holley, MD, is a professor of medicine at Uniformed Services University in Bethesda, Maryland, and a pulmonary/sleep and critical care medicine physician at MedStar Washington Hospital Center in Washington, DC. He covers a wide range of topics in pulmonary, critical care, and sleep medicine.

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