Persisting neuroendocrine abnormalities and their association with physical impairment 5 years after critical illness

A schedule for tapering glucocorticoid treatment in patients with severe SARS-CoV 2 infection can prevent acute adrenal insufficiency in the geriatric population

OBJECTIVE AND DESIGN

Glucocorticoids (GCs) have been widely used in symptomatic patients for the treatment of COVID-19. The risk for adrenal insufficiency must be considered after GC withdrawal given that it is a life-threatening condition if left unrecognized and untreated. Our study aimed to diagnose adrenal insufficiency early on through a GC reduction schedule in patients with COVID-19 infection.

PATIENTS AND MEASUREMENTS

From November 2021 to May 2022, 233 patients were admitted to the Geriatric Division of the University Hospital of Padova with COVID-19 infection. A total of 122 patients were treated with dexamethasone, after which the GC tapering was performed according to a structured schedule. It consists of step-by-step GC tapering with prednisone, from 25 mg to 2.5 mg over 2 weeks. Morning serum sodium, potassium, and cortisol levels were assessed 3 days after the last dose of prednisone.

RESULTS

At the end of GC withdrawal, no adrenal crisis or signs/symptoms of acute adrenal insufficiency were reported. Median serum cortisol, sodium, and potassium levels after GC discontinuation were, respectively, 427 nmol/L, 140 nmol/L, and 4 nmol/L (interquartile range 395-479, 138-142, and 3.7-4.3). A morning serum cortisol level below the selected threshold of 270 nmol/L was observed in two asymptomatic cases (respectively, 173 and 239 nmol/L, reference range 138-690 nmol/L). Mild hyponatremia (serum sodium 132 to 134 nmol/L, reference range 135-145 nmol/L) was detected in five patients, without being related to cortisol levels.

CONCLUSIONS

A structured schedule for the tapering of GC treatment used in patients with severe COVID-19 can reduce the risk of adrenal crisis and acute adrenal insufficiency.

The hypothalamus-pituitary-adrenal axis in sepsis- and hyperinflammation-induced critical illness: Gaps in current knowledge and future translational research directions

The classical model of the vital increase in systemic glucocorticoid availability in response to sepsis- and hyperinflammation-induced critical illness is one of an activated hypothalamus-pituitary-adrenocortical axis. However, research performed in the last decade has challenged this rather simple model and has unveiled a more complex, time-dependent set of responses. ACTH-driven cortisol production is only briefly increased, rapidly followed by orchestrated peripheral adaptations that maintain increased cortisol availability for target tissues without continued need for increased cortisol production and by changes at the target tissues that guide and titrate cortisol action matched to tissue-specific needs. One can speculate that these acute changes are adaptive and that treatment with stress-doses of hydrocortisone may negatively interfere with these adaptive changes. These insights also suggest that prolonged critically ill patients, treated in the ICU for several weeks, may develop central adrenal insufficiency, although it remains unclear how to best diagnose and treat this condition.

Poor physical recovery after critical illness: incidence, features, risk factors, pathophysiology, and evidence-based therapies

PURPOSE OF REVIEW

To summarize the incidence, features, pathogenesis, risk factors, and evidence-based therapies of prolonged intensive care unit (ICU) acquired weakness (ICU-AW). We aim to provide an updated overview on aspects of poor physical recovery following critical illness.

RECENT FINDINGS

New physical problems after ICU survival, such as muscle weakness, weakened condition, and reduced exercise capacity, are the most frequently encountered limitations of patients with postintensive care syndrome. Disabilities may persist for months to years and frequently do not fully recover. Hormonal and mitochondrial disturbances, impaired muscle regeneration due to injured satellite cells and epigenetic differences may be involved in sustained ICU-AW. Although demographics and ICU treatment factors appear essential determinants for physical recovery, pre-ICU health status is also crucial. Currently, no effective treatments are available. Early mobilization in the ICU may improve physical outcomes at ICU-discharge, but there is no evidence for benefit on long-term physical recovery.

SUMMARY

Impaired physical recovery is observed frequently among ICU survivors. The pre-ICU health status, demographic, and ICU treatment factors appear to be important determinants for physical convalescence during the post-ICU phase. The pathophysiological mechanisms involved are poorly understood, thereby resulting in exiguous evidence-based treatment strategies to date.

Novel insights in endocrine and metabolic pathways in sepsis and gaps for future research

Sepsis is defined as any life-threatening organ dysfunction caused by a dysregulated host response to infection. It remains an important cause of critical illness and has considerable short- and long-term morbidity and mortality. In the last decades, preclinical and clinical research has revealed a biphasic pattern in the (neuro-)endocrine responses to sepsis as to other forms of critical illness, contributing to development of severe metabolic alterations. Immediately after the critical illness-inducing insult, fasting- and stress-induced neuroendocrine and cellular responses evoke a catabolic state in order to provide energy substrates for vital tissues, and to concomitantly activate cellular repair pathways while energy-consuming anabolism is postponed. Large randomized controlled trials have shown that providing early full feeding in this acute phase induced harm and reversed some of the neuro-endocrine alterations, which suggested that the acute fasting- and stress-induced responses to critical illness are likely interlinked and benefical. However, it remains unclear whether, in the context of accepting virtual fasting in the acute phase of illness, metabolic alterations such as hyperglycemia are harmful or beneficial. When patients enter a prolonged phase of critical illness, a central suppression of most neuroendocrine axes follows. Prolonged fasting and central neuroendocrine suppression may no longer be beneficial. Although pilot studies have suggested benefit of fasting-mimicking diets and interventions that reactivate the central neuroendocrine suppression selectively in the prolonged phase of illness, further study is needed to investigate patient-oriented outcomes in larger randomized trials.

Critical Illness-induced Corticosteroid Insufficiency: What It Is Not and What It Could Be

Critical illnesses are hallmarked by increased systemic cortisol availability, a vital part of the stress response. Acute stress may trigger a life-threatening adrenal crisis when a disease of the hypothalamic-pituitary-adrenal (HPA) axis is present and not adequately treated with stress doses of hydrocortisone. Stress doses of hydrocortisone are also used to reduce high vasopressor need in patients suffering from septic shock, in the absence of adrenal insufficiency. Research performed over the last 10 years focusing on the HPA axis during critical illness has led to the insight that neither of these conditions can be labeled "critical illness-induced corticosteroid insufficiency" or CIRCI. Instead, these data suggested using the term CIRCI for a condition that may develop in prolonged critically ill patients. Indeed, when patients remain dependent on vital organ support for weeks, they are at risk of acquiring central adrenal insufficiency. The sustained increase in systemic glucocorticoid availability, mainly brought about by suppressed circulating cortisol-binding proteins and suppressed hepatic/renal cortisol metabolism, exerts negative feedback inhibition at the hypothalamus/pituitary, while high levels of other glucocorticoid receptor ligands, such as bile acids, and drugs, such as opioids, may further suppress adrenocorticotropic hormone (ACTH) secretion. The adrenal cortex, depleted from ACTH-mediated trophic signaling for weeks, may become structurally and functionally impaired, resulting in insufficient cortisol production. Such a central HPA axis suppression may be maladaptive by contributing to lingering vasopressor need and encephalopathy, hence preventing recovery. Here, we review this concept of CIRCI and we advise on how to recognize and treat this poorly understood condition.