CORTISOL IN SEVERELY BURNED PATIENTS: INVESTIGATIONS ON DISTURBANCE OF THE HYPOTHALAMIC-PITUITARY-ADRENAL AXIS

The impact of burn injury on the central nervous system

Burn injuries can be devastating, with life-long impacts including an increased risk of hospitalization for a wide range of secondary morbidities. One area that remains not fully understood is the impact of burn trauma on the central nervous system (CNS). This review will outline the current findings on the physiological impact that burns have on the CNS and how this may contribute to the development of neural comorbidities including mental health conditions. This review highlights the damaging effects caused by burn injuries on the CNS, characterized by changes to metabolism, molecular damage to cells and their organelles, and disturbance to sensory, motor and cognitive functions in the CNS. This damage is likely initiated by the inflammatory response that accompanies burn injury, and it is often long-lasting. Treatments used to relieve the symptoms of damage to the CNS due to burn injury often target inflammatory pathways. However, there are non-invasive treatments for burn patients that target the functional and cognitive damage caused by the burn, including transcranial magnetic stimulation and virtual reality. Future research should focus on understanding the mechanisms that underpin the impact of a burn injury on the CNS, burn severity thresholds required to inflict damage to the CNS, and acute and long-term therapies to ameliorate deleterious CNS changes after a burn.

Surviving Sepsis After Burn Campaign

INTRODUCTION

The Surviving Sepsis Campaign was developed to improve outcomes for all patients with sepsis. Despite sepsis being the primary cause of death after thermal injury, burns have always been excluded from the Surviving Sepsis efforts. To improve sepsis outcomes in burn patients, an international group of burn experts developed the Surviving Sepsis After Burn Campaign (SSABC) as a testable guideline to improve burn sepsis outcomes.

METHODS

The International Society for Burn Injuries (ISBI) reached out to regional or national burn organizations to recommend members to participate in the program. Two members of the ISBI developed specific "patient/population, intervention, comparison and outcome" (PICO) questions that paralleled the 2021 Surviving Sepsis Campaign [1]. SSABC participants were asked to search the current literature and rate its quality for each topic. At the Congress of the ISBI, in Guadalajara, Mexico, August 28, 2022, a majority of the participants met to create "statements" based on the literature. The "summary statements" were then sent to all members for comment with the hope of developing an 80% consensus. After four reviews, a consensus statement for each topic was created or "no consensus" was reported.

RESULTS

The committee developed sixty statements within fourteen topics that provide guidance for the early treatment of sepsis in burn patients. These statements should be used to improve the care of sepsis in burn patients. The statements should not be considered as "static" comments but should rather be used as guidelines for future testing of the best treatments for sepsis in burn patients. They should be updated on a regular basis.

CONCLUSION

Members of the burn community from the around the world have developed the Surviving Sepsis After Burn Campaign guidelines with the goal of improving the outcome of sepsis in burn patients.

Pathological changes in the brain after peripheral burns

Brain injuries are common complications in patients with thermal burns and are associated with unpleasant outcomes. In clinical settings, it was once believed that brain injuries were not major pathological processes after burn, at least in part due to the unavailability of specific clinical manifestations. Burn-related brain injuries have been studied for more than a century, but the underlying pathophysiology has not been completely clarified. This article reviews the pathological changes in the brain following peripheral burns at the anatomical, histological, cytological, molecular and cognitive levels. Therapeutic indications based on brain injury as well as future directions for research have been summarized and proposed.

Researches on cognitive sequelae of burn injury: Current status and advances

Burn injury is a devastating disease with high incidence of disability and mortality. The cognitive dysfunctions, such as memory defect, are the main neurological sequelae influencing the life quality of burn-injured patients. The post-burn cognitive dysfunctions are related to the primary peripheral factors and the secondary cerebral inflammation, resulting in the destruction of blood-brain barrier (BBB), as is shown on Computed Tomography (CT) and magnetic resonance imaging examinations. As part of the neurovascular unit, BBB is vital to the nutrition and homeostasis of the central nervous system (CNS) and undergoes myriad alterations after burn injury, causing post-burn cognitive defects. The diagnosis and treatment of cognitive dysfunctions as burn injury sequelae are of great importance. In this review, we address the major manifestations and interventions of post-burn cognitive defects, as well as the mechanisms involved in memory defect, including neuroinflammation, destruction of BBB, and hormone imbalance.

Screening of Key Genes in Severe Burn Injury at Different Stages via Analyzing Gene Expression Data

Microarray analysis was performed to investigate the changes in gene expression profiles after severe burn injury at the early and middle stages, further discovering therapeutic targets for severe burn injury. Microarray data (GSE19743) were downloaded from Gene Expression Omnibus. First, differentially expressed genes (DEGs) at different stages were screened using limma package. Gene Ontology (GO) functional annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis of DEGs were then performed using DAVID. Protein-protein interaction (PPI) networks were also constructed using String database. Additionally, transcription factor binding site was detected using the Whole-Genome rVISTA. Compared with the healthy controls, 160 DEGs were identified in patients with early-stage burn injury and 261 DEGs were obtained in patients with middle-stage burn injury. Only 10 genes showed differential expression between the early and middle stages. KEGG functional analysis indicated that DEGs detected at the early stage were mainly enriched in the immune response, kinase activity, and signaling pathways and DEGs detected at the middle stage were involved in the immune response, protein and fat metabolism, and programmed cell death pathways. Three PPI networks were constructed and hub proteins with high degrees of connection were screened, such as lactotransferrin, interleukin 8, and perforin-1. Additionally, many transcription factor binding sites that may be involved in the regulation of these DEGs were also detected. A number of DEGs were identified in patients with early- and middle-stage burn injury, which helps to deepen the understanding about the molecular mechanism underlying severe burn injury.

Refractory collapse and severe burn: Think about acute adrenal insufficiency

INTRODUCTION

Adrenal insufficiency (AI) is a rare endocrine disorder, which can in its acute form be life-threatening in case of late diagnosis or treatment. The stress during a thermal burn can easily decompensate the AI. We report the case of an acute adrenal insufficiency (AAI) discovered following a refractory collapse occurred after a severe thermal burn.

CASE PRESENTATION

A 60-year-old woman was accidentally burned to the lower limbs by hot water. Total burn surface area was 36 %. The patient had local care and dressings, vascular filling, and analgesics. Four hours later, she became dyspneic, and presented tachycardia associated with collapse at 60/40mmHg. Suspecting a hypovolemic origin, we performed a solid fluid replacement with colloids. However, hemodynamic stability was not achieved and motivated a continuous injection of norepinephrine. Despite high doses, immediate evolution was marked by a persistent precarious hemodynamic state. AAI was suspected, and a substitutive hormonotherapy was started. The clinical condition progressively improved and catecholamines were quickly stopped.

CONCLUSION

AAI is a vital emergency. The large burn is a possible cause of the AI decompensation. This diagnosis must be kept in mind when the hemodynamic status remains unstable despite an adequate vascular treatment.

Suspected adrenal insufficiency in critically ill burned patients: etomidate-induced or critical illness-related corticosteroid insufficiency?-A review of the literature

Adrenal insufficiency (AI), whether etomidate-induced or secondary to critical illness-related corticosteroid insufficiency (CIRCI), is a common and under appreciated problem in the intensive care unit intensive care unit (ICU). However, AI is often difficult to identify and diagnose in the critically ill. The pathophysiology and ideal management of etomidate-induced AI and CIRCI, especially in burn patients, is unknown. Many studies, however, have examined the prevalence of and risk factors for developing AI in critically ill populations as well as the effect of AI on morbidity and mortality. Observing a seemingly increased number of patients with suspected AI in our burn ICU, we sought to evaluate and summarize the current literature relating to adrenal insufficiency in the critically ill. We performed an electronic literature search on the PubMed and Ovid Medline databases using the key words "etomidate," "adrenal insufficiency," "CIRCI," and "burn injury." Relevant studies from the current burn and ICU era were selected to be included in this review of the literature. Among the critically ill, burn patients are at increased risk for developing adrenal insufficiency and the risk is greatest for elderly patients with large burns and inhalation injury. Both CIRCI and etomidate-induced AI are associated with high morbidity and mortality, therefore avoiding preventable causes of AI, such as choosing alternatives to etomidate for rapid sequence intubation (RSI) in the severely burn injured patient should be encouraged. Further research is indicated to investigate the biological relationship between AI and associated morbidity and mortality, whether etomidate-induced or secondary to critical illness; as well as how best to identify and diagnose patients with suspected adrenal insufficiency in the burn intensive care unit.

Intraoperative target-controlled infusion anesthesia application using remifentanil hydrochloride with etomidate in patients with severe burn as monitored using Narcotrend

OBJECTIVE

This study aims to evaluate the feasibility of intraoperative composite target-controlled infusion (TCI) anesthesia application using remifentanil hydrochloride with etomidate in patients with severe burns, as monitored by Narcotrend.

METHODS

A total of 40 patients with severe burns with eschar excisions and skin grafts were randomly and equally grouped into the etomidate (E) and the propofol groups (P). Anesthesia was induced and maintained by a remifentanil hydrochloride TCI combined with etomidate or propofol. The depth of anesthesia and other relevant indicators were recorded through intraoperative electroencephalogram monitoring using a Narcotrend monitor.

RESULTS

No statistically significant differences were observed between the drug withdrawal times, eye opening requirements, or orientation recoveries of the two groups (P>0.05). The cortisol and aldosterone levels in group E were significantly lower than those in group P 24h post operation (P<0.05). No significant differences between the number of operations, hospitalization duration, mean arterial pressure, heart rate, and postoperative adverse reaction incidence of the two groups were observed at each time point (P>0.05).

CONCLUSION

The application of a composite remifentanil hydrochloride combined with etomidate TCI is feasible for the early eschar excision in patients with severe burns.

The endocrine response to severe burn trauma

The endocrine system is frequently altered after a major burn trauma. Besides the endocrine response to stress characterized by hypercortisolism, several hypothalamus-hypophysis-target gland axes are rapidly perturbed within a few days. These alterations can persist in the long term and deserve an appropriate treatment. Disturbances in water clearance and glucidic metabolism are also common and need to be diagnosed and corrected to decrease morbidity in such patients. Bone and mineral metabolism is deeply compromised and requires correction of mineral abnormalities in order to improve symptoms and prevent bone loss. No large prospective and/or intervention trials are available to date to elaborate age-related, evidence-based recommendations to monitor and treat burn-related endocrine alterations.

The evaluation of the adrenal and thyroid axes and glucose metabolism after burn injury in children

INTRODUCTION

Burn injury is an important trauma and can cause many hormonal and metabolic changes in the human body. In contrast to the situation with adults, there are inadequate number of studies on children with this condition. Our aim in this study was to determine the changes in the adrenal, thyroid axes and glucose metabolism in the acute and subacute period and relation to the percent total body surface area (TBSA) burned in children with major burn injury.

PATIENTS AND METHOD

A total of 90 hospitalized children aged 0-13 years (mean: 3.44 +/- 2.90 years) with major fluid burn injury were included in this study. Serum ACTH, cortisol, fasting glucose and insulin and thyroid hormones (free T3 and T4, TSH) were evaluated in the first 24 hours after the burn injury and on day 3 and month 3 consequently in all of the cases. An ACTH stimulation test was performed when necessary. Continuous variables were compared with analysis of variance and categorical variables were compared with the chi-square test. The Pearson correlation was used to determine the relation between ACTH and cortisol and between blood glucose and insulin (on day 1 and 3 and month 3). Also the correlation with the TBSA burned and the hormonal values were evaluated. A p value <0.05 was considered statistically significant.

FINDINGS

ACTH and Cortisol level increased in first 24 hours and decreased significantly by time. The change of ACTH and Cortisol level with time was significantly related to the TBSA burned. ACTH and cortisol levels were found significantly correlated in each time-point, but the correlation was highest in 3rd month. The glucose level in the first 24 hours was significantly higher than day 3 and month 3 levels in all of the children. There was again a significant increase in the serum insulin level in the first 24 hours. However there was no difference between day 1 and 3 serum insulin levels. A correlation was found between serum glucose and insulin on the first day but not on day 3 or month 3. Free T3 and T4 levels increased by time. Pairwise comparisons indicated that 1st day free T3 and T4 level was significantly lower than both 3rd day and 3rd month levels.

CONCLUSION

ACTH, Cortisol and fasting blood glucose level increased significantly however serum insulin level was slightly higher in first 24 hours after burns in children. Thyroid hormones were found to be decreased acute period following burns but staying in normal levels.

Critical care of the burn patient: the first 48 hours

OBJECTIVE

The goal of this concise review is to provide an overview of some of the most important resuscitation and monitoring issues and approaches that are unique to burn patients compared with the general intensive care unit population.

STUDY SELECTION

Consensus conference findings, clinical trials, and expert medical opinion regarding care of the critically burned patient were gathered and reviewed. Studies focusing on burn shock, resuscitation goals, monitoring tools, and current recommendations for initial burn care were examined.

CONCLUSIONS

The critically burned patient differs from other critically ill patients in many ways, the most important being the necessity of a team approach to patient care. The burn patient is best cared for in a dedicated burn center where resuscitation and monitoring concentrate on the pathophysiology of burns, inhalation injury, and edema formation. Early operative intervention and wound closure, metabolic interventions, early enteral nutrition, and intensive glucose control have led to continued improvements in outcome. Prevention of complications such as hypothermia and compartment syndromes is part of burn critical care. The myriad areas where standards and guidelines are currently determined only by expert opinion will become driven by level 1 data only by continued research into the critical care of the burn patient.

Release of melanotroph- and corticotroph-type proopiomelanocortin derivatives into blood after administration of corticotropin-releasing hormone in patients with septic shock without adrenocortical insufficiency

The aim of the study was to assess the adequacy of pituitary function by determining the plasma concentrations of corticotroph-type (corticotropin, beta-endorphin immunoreactive material [beta-END IRM], authentic beta-END, and beta-lipotropin IRM) as well as melanotroph-type (alpha-melanocyte-stimulating hormone [alpha-MSH] and N-acetyl-beta-END [Nac-beta-END] IRM) proopiomelanocortin (POMC) derivatives in patients under septic shock upon administration of corticotropin-releasing hormone (CRH). The objectives were to assess whether an insufficient release of corticotroph- or melanotroph-type POMC derivatives from the pituitary into the cardiovascular compartment correlates with the 28-day mortality rate. Seventeen patients with septic shock but without adrenocortical insufficiency and 16 healthy volunteers were enrolled in the study, and CRH stimulation tests were performed with an i.v. bolus injection of 100 microg human CRH. After treatment with CRH, plasma concentrations of corticotroph-type POMC derivatives increased in survivors and nonsurvivors, melanotroph-type POMC derivatives such as alpha-MSH or Nac-beta-END IRM increased only in survivors in contrast to nonsurvivors. The release of alpha-MSH and Nac-beta-END IRM was suppressed by dexamethasone in survivors but not in nonsurvivors. In patients with septic shock, the response of the pituitary to CRH stimulation in terms of alpha-MSH or Nac-beta-END IRM release was impaired in nonsurvivors compared with survivors or controls. Reduced responses of alpha-MSH or Nac-beta-END IRM to CRH and the invalid suppression by dexamethasone reflect a state of dysfunction of the melanotroph-type POMC system in nonsurvivors. Considering anticytokine and anti-inflammatory effects of alpha-MSH, this dysfunction may increase the risk of death in patients with septic shock.

The year in burns 2007

In the year 2007, approximately 1000 original burn research articles were published in scientific journals using the English language. This article reviews approximately 90 of these which were deemed by the author to be the most important in terms of clinical burn care. Relevant topics include epidemiology, wound characterisation, critical care physiology, inhalation injury, infection, metabolism and nutrition, psychological considerations, pain management, rehabilitation, and burn reconstruction. Each selected article is mentioned briefly with editorial comment.