The Safety and Efficacy of Propranolol in Reducing the Hypermetabolic Response in the Pediatric Burn Population

THE RISKS OF FIRST ONSET PRIMARY HYPERTENSION DIAGNOSIS IN THERMAL-INJURED PATIENTS

ABSTRACT

Introduction: Hypertension is a prevalent condition in the United States and leads to an increased risk of developing various comorbidities. However, the impact of new-onset hypertension after severe burns on patient outcomes is not known. We posit that hypertension onset after severe burn is associated with increased risk of developing comorbidities and mortality. Methods: Using the TriNetX database, burned patients diagnosed with essential hypertension after injury were compared with those who did not develop hypertension; neither had prior hypertension. Each cohort was grouped by sex, percent total body surface area (TBSA) burned, and age, then propensity matched for sex, race, ethnicity, and laboratory values. Outcomes assessed were acute kidney injury (AKI), hyperglycemia, heart failure, myocardial infarction (MI), and death. Results: Those diagnosed with hypertension after severe burn were 4.9 times more likely to develop AKI, 3.6 times for hyperglycemia, 5.3 times for heart failure, 4.7 times for acute MI, and 1.5 times for mortality. Sex analysis shows that men were at greater risk for AKI (1.5 times), heart failure (1.1 times), and death (1.4 times). Women were 1.3 times more likely to develop hyperglycemia. Percent TBSA burned grouping showed increased risk for all outcomes with increasing severity. Age grouping indicated an elevated risk of developing AKI, heart failure, acute MI, and death. Conclusion: New-onset hypertension diagnosis in severely burned patients is associated with acute kidney injury, heart failure, acute MI, and death. Overall, males, older patients, and those with a higher % TBSA burned are at a higher risk of developing these comorbidities.

Pharmacologic Management of Pediatric Burns

Many pediatric patients with burn injuries may be initially treated in a hospital where pediatric specialized care, including resources and trained personnel may be limited. This includes resuscitation in adult emergency departments and inpatient care in mixed adult-pediatric burn units. The intent of this review is to provide a compilation of topics for the adult trained pharmacist or another healthcare practitioner on the management of pediatric patients with burn injuries. This article focuses on several key areas of pharmacologic burn management in the pediatric patient that may differ from the adult patient, including pain and sedation, fluid resuscitation, nutrition support, antimicrobial selection, anticoagulation, and inhalation injury. It is important that all clinicians have resources to help optimize the management of burn injuries in the pediatric population as, in addition to burn injury itself, pediatric patients have different pharmacokinetics and pharmacodynamics affecting which medications are used and how they are dosed. This article highlights several key differences between pediatric and adult patients, providing an additional resource to assist adult-trained pharmacists or other healthcare practitioners with making clinical decisions in the pediatric burn population.

Mechanism and application of β-adrenoceptor blockers in soft tissue wound healing

Soft tissue damage stimulates sympathetic nerves to release large amounts of catecholamine hormones which bind to β-adrenergic receptors (β-ARs) on the cell membrane surface. It activates the downstream effector molecules and impairs soft tissue wound healing. β-blockers specifically inhibit β-ARs activation in acute/chronic skin lesions and ulcerative hemangiomas. They also accelerate soft tissue wound healing by shortening the duration of inflammation, speeding keratinocyte migration and reepithelialization, promoting wound contraction and angiogenesis, and inhibiting bacterial virulence effects. In addition, β-blockers shorten wound healing periods in patients with severe thermal damage by reducing the hypermetabolic response. While β-blockers promote/inhibit corneal epithelial cell regeneration and restores limbal stem/progenitor cells function, it could well accelerate/delay corneal wound healing. Given these meaningful effects, a growing number of studies are focused on examining the efficacy and safety of β-blockers in soft tissue wound repair, including acute and chronic wounds, severe thermal damage, ulcerated infantile hemangioma, corneal wounds, and other soft tissue disorders. However, an intensive investigation on their acting mechanisms is imperatively needed. The purpose of this article is to summerize the roles of β-blockers in soft tissue wound healing and explore their clinical applications.

Introduction: The Multidisciplinary Team Approach to Burn Care

Since the first burn units were established following World War II, great advances in understanding and treating burn shock, smoke inhalation injury, pneumonia, and invasive burn wound infections, and in achieving early burn-wound closure, have greatly decreased postburn morbidity and mortality. These advances were the result of closely integrated multidisciplinary teams of clinicians and researchers. The team approach to burns is a model for success in the care of any challenging clinical problem.

The use of propranolol in adult burn patients: Safety and outcome influence

OBJECTIVES

This study investigated safety and effect of propranolol on adult patients with severe burn.

METHODS

A prospective study was conducted on 124 severely adult burn patients who were randomly divided into propranolol and non-propranolol group. Propranolol was given by nasogastric tube to achieve the target of lowering 15-20% of initial heart rate.

RESULTS

Average dose of propranolol was 1.9 ± 0.5 mg/kg/day ranging from 0.9 to 3.3 mg/kg/day and was not affected by burn extent and inhalation injury. Mean heart rate reduced by 21.2% during the 28 day period. Recorded adverse events included hypotension (11.9%), bradycardia (1.6%), hypoglycemia (17.7%) and total number of held events was 8 occurring in 7 (11.3%) patients. Serum levels of glucose, total protein, albumin, cholesterol and triglyceride at different times were not significantly different between the two groups. Significantly lower resting energy expenditure on the 7^th and 14^th day were seen in propranolol group (p < 0.05). After 3 weeks, liver size in the propranolol group did not change significantly from admission, while in the non-propranolol group, liver size increased significantly (p < 0.05). The complete healing time of partial-thickness burns and donor sites were significantly shorter in propranolol group (p < 0.01). Duration of ventilation, length of stay in intensive care unit and in hospital, number of operations, rate of multiple organ failure, and death were not different between the two groups (p > 0.05).

CONCLUSION

For severely burned adults, propranolol was safe and effective on reducing energy expenditure, limited hepatomegaly, and accelerated partial burn wound and donor site closure, but does not affect length of stay in ICU, hospitalization, complication ormortality rate.

Application of beta-blockers in burn management

Severe burn injuries cause chronic inflammation, which produces a subsequent hypermetabolic response that starts immediately and persists for at least 3 years. The hypermetabolic state, which is thought to be due to postburn elevations of endogenous catecholamines and cortisol, is associated with a number of harmful physiologic derangements including immunosuppression, impaired wound healing, muscle catabolism, and hepatic dysfunction. Beta-blockers have become first line agents for reducing these adverse effects of hypermetabolism in severe burns. This review discusses the underlying pharmacological mechanisms demonstrated by clinical studies evaluating the safety and efficacy of beta-blockers in the management of burn injuries. A literature search was performed using the PubMed database to identify articles on beta-blockers and burn management. The review yielded 33 relevant results consisting of randomized controlled trials, original research articles, and meta-analyses in pediatric and adult burn patients. Propranolol administration reduced insulin resistance, lipolysis, proteolysis, cardiac work, and bone loss resulting from burn-associated hypermetabolism. Propranolol also effectively reduced myocardial stress, resting energy expenditure, and central deposition of fat. Recent studies have begun to evaluate incorporation of anabolic agents and rehabilitative exercise therapy. However, at this time propranolol continues to be the most effective therapy for reducing the hypermetabolic response and other morbidities resulting from burn injuries.

Burn-induced hypermetabolism and skeletal muscle dysfunction

Critical illnesses, including sepsis, cancer cachexia, and burn injury, invoke a milieu of systemic metabolic and inflammatory derangements that ultimately results in increased energy expenditure leading to fat and lean mass catabolism. Burn injuries present a unique clinical challenge given the magnitude and duration of the hypermetabolic response compared with other forms of critical illness, which drastically increase the risk of morbidity and mortality. Skeletal muscle metabolism is particularly altered as a consequence of burn-induced hypermetabolism, as it primarily provides a main source of fuel in support of wound healing. Interestingly, muscle catabolism is sustained long after the wound has healed, indicating that additional mechanisms beyond wound healing are involved. In this review, we discuss the distinctive pathophysiological response to burn injury with a focus on skeletal muscle function and metabolism. We first examine the diverse consequences on skeletal muscle dysfunction between thermal, electrical, and chemical burns. We then provide a comprehensive overview of the known mechanisms underlying skeletal muscle dysfunction that may be attributed to hypermetabolism. Finally, we review the most promising current treatment options to mitigate muscle catabolism, and by extension improve morbidity and mortality, and end with future directions that have the potential to significantly improve patient care.

The impact of catecholamines on skeletal muscle following massive burns: Friend or foe?

Profound skeletal muscle wasting in the setting of total body hypermetabolism is a defining characteristic of massive burns, compromising the patient's recovery and necessitating a protracted period of rehabilitation. In recent years, the prolonged use of the non-selective beta-blocker, propranolol, has gained prominence as an effective tool to assist with suppressing epinephrine-dependent burn-induced hypermetabolism and by extension, blunting muscle catabolism. However, synthetic β-adrenergic agonists, such as clenbuterol, are widely associated with the promotion of muscle growth in both animals and humans. Moreover, experimental adrenodemedullation is known to result in muscle catabolism. Therefore, the blunting of muscle β-adrenergic signaling via the use of propranolol would be expected to negatively impair muscle protein homeostasis. This review explores these paradoxical observations and identifies the manner by which propranolol is thought to exert its anti-catabolic effects in burn patients. Moreover, we identify potential avenues by which the use of beta-blocker therapy in the treatment of massive burns could potentially be further refined to promote the recovery of muscle mass in these critically ill patients while continuing to ameliorate total body hypermetabolism.

Pediatric burn care: new techniques and outcomes

PURPOSE OF REVIEW

Thermal injury is a leading cause of morbidity and mortality in children. This review highlights the current management of thermal injury and its complications.

RECENT FINDINGS

Many recent advances in burn care have improved the outcomes of patients with thermal injury; however, variability does exist, and there are many opportunities for improvement. This review will highlight the complexity of issues encountered along the continuum of care for thermal injury patients. Accurate estimation of total burn surface area (TBSA) of a burn continues to be a challenge in pediatric patients. Variability continues to exist surrounding the management of burn resuscitation and complex wounds. Children with extensive burns have profound immune and metabolic changes that can lead to multiple complications, including infections, growth arrest, and loss of lean body mass. Standardization in measurements related to quality of life and psychological stress following pediatric thermal injury is much needed.

SUMMARY

The care of pediatric patients with thermal injury is complex and multifaceted. This review highlights the most recent advances in pediatric burn care.