Preserving Vision: Rethinking Burn Patient Monitoring to Prevent Orbital Compartment Syndrome

American Burn Association Clinical Practice Guidelines on Burn Shock Resuscitation

This Clinical Practice Guideline (CPG) addresses the topic of acute fluid resuscitation during the first 48 hours following a burn injury for adults with burns ≥20% of the total body surface area (%TBSA). The listed authors formed an investigation panel and developed clinically relevant PICO (Population, Intervention, Comparator, Outcome) questions. A systematic literature search returned 5978 titles related to this topic and after 3 levels of screening, 24 studies met criteria to address the PICO questions and were critically reviewed. We recommend that clinicians consider the use of human albumin solution, especially in patients with larger burns, to lower resuscitation volumes and improve urine output. We recommend initiating resuscitation based on providing 2 mL/kg/% TBSA burn in order to reduce resuscitation fluid volumes. We recommend selective monitoring of intra-abdominal and intraocular pressure during burn shock resuscitation. We make a weak recommendation for clinicians to consider the use of computer decision support software to guide fluid titration and lower resuscitation fluid volumes. We do not recommend the use of transpulmonary thermodilution-derived variables to guide burn shock resuscitation. We are unable to make any recommendations on the use of high-dose vitamin C (ascorbic acid), fresh frozen plasma (FFP), early continuous renal replacement therapy, or vasopressors as adjuncts during acute burn shock resuscitation. Mortality is an important outcome in burn shock resuscitation, but it was not formally included as a PICO outcome because the available scientific literature is missing studies of sufficient population size and quality to allow us to confidently make recommendations related to the outcome of survival at this time.

Orbital Compartment Syndrome in Severe Burns: Predictive Factors, Timing, and Complications of Intervention

PURPOSE

Severe burn patients require high-volume fluid resuscitation, which increases risk for orbital compartment syndrome (OCS). We aimed to understand surgeons' practice patterns and to examine risk factors for OCS, timing of lateral canthotomy and cantholysis (LCC), and complications of intervention.

METHODS

A survey of American Society of Ophthalmic Plastic and Reconstructive Surgery and North American Society of Academic Orbital Surgeons' practice patterns in burn patients was undertaken. In addition, a retrospective analysis was conducted of 107 patients with burns greater than 20% total body surface area at 1 institution from January 1, 2009, to June 1, 2018. Patients with Stevens-Johnson Syndrome or Toxic Epidermal Necrolysis, frostbite, or no ophthalmologic consultation were excluded. Risk factors for OCS, timing of LCC, and complications of the intervention were examined.

RESULTS

In the survey, 37 of 54 respondents had treated burn patients, of which 29 followed no protocol. Threshold intraocular pressure for intervention varied widely, and nearly all reported having seen complications from LCC in burn patients. For the retrospective analysis, 107 patients met criteria, of which 22 (20.6%) required LCC. Renal failure, inhalation injury, eyelid burns, higher total body surface area, elevated lactate, increased number of escharotomies, and greater total fluid required were significantly associated with the clinical decision that the patient was at risk for OCS requiring LCC. Fluid resuscitation in excess of the Ivy Index (250 ml/kg) increased odds of LCC 8.6 times. Average time of LCC was 15.8 hours after burn. LCC patients experienced higher rates of complications including eyelid retraction, exposure keratopathy, and corneal ulceration.

CONCLUSIONS

Severe burn patients should be monitored closely by an ophthalmologist during the first 48 hours for signs of OCS. Further studies should aim to recommend protocols guiding evaluation and intervention.

The First 24 Hours: Burn Shock Resuscitation and Early Complications

Resuscitation is required for the management of patients with severe thermal injury. Some of the initial pathophysiologic events following burn injury include an exaggerated inflammatory state, injury to the endothelium, and increased capillary permeability, which all culminate in shock. Understanding these processes is critical to the effective management of patients with burn injuries. Formulas predicting fluid requirements during burn resuscitation have evolved over the past century in response to clinical experience and research efforts. Modern resuscitation features individualized fluid titration and monitoring along with colloid-based adjuncts. Despite these developments, complications from over-resuscitation still occur.

Burn Shock and Resuscitation: Review and State of the Science

Burn shock and acute fluid resuscitation continue to spark intense interest and debate among burn clinicians. Following a major burn injury, fluid resuscitation of burn shock is life-saving, but paradoxically can also be a source of increased morbidity and mortality because of the unintended consequence of systemic edema formation. Considerable research over the past two decades has been devoted to understanding the mechanisms of edema formation, and to develop strategies to curb resuscitation fluids and limit edema development. Recognition of burn endotheliopathy - injury to the endothelium's glycocalyx layer- is one of the most important recent developments in our understanding of burn shock pathophysiology. Newer monitoring approaches and resuscitation endpoints, along with alternative resuscitation strategies to crystalloids alone, such as administration of albumin, or plasma, or high dose ascorbic acid, have had mixed results in limiting fluid creep. Clear demonstration of improvements in outcomes with all of these approaches remains elusive. This comprehensive review article on burn shock and acute resuscitation accompanies the American Burn Association's State of the Science meeting held in New Orleans, LA on November 2-3, 2021 and the Proceedings of that conference published in this journal.

Minimally invasive measurement of orbital compartment pressure and implications for orbital compartment syndrome: a pilot study

BACKGROUND

Diagnosis of orbital compartment syndrome is mainly based on clinical findings, such as intraocular pressure and proptosis, which try to estimate the orbital compartment pressure. However, the reliability of these surrogates is unclear. Current techniques for the direct measurement of orbital compartment pressure are widely experimental and impractical in the clinical setting. Our aim was to explore the feasibility of minimally invasive needle manometry for direct measurement of orbital compartment pressure under reproducible conditions in an in vivo model of orbital congestion. We further sought to evaluate intraocular pressure and proptosis as indicators for elevated orbital compartment pressure.

METHODS

A total of 7 ml of mepivacaine 2% solution was injected into the orbital compartment in 20 patients undergoing cataract surgery under local anesthesia. A commercially available single-use manometer device was inserted between the syringe and the injection needle to measure the orbital compartment pressure for each milliliter of intraorbital volume increment. Additionally, intraocular pressure (subgroup A; n = 10) or axial globe position (subgroup B; n = 10) were measured.

RESULTS

Needle manometry allowed for rapid and continuous measurement of orbital compartment pressure. Overall mean orbital compartment pressure increased from 2.5 mmHg pre- to 12.8 mmHg post-interventionally. Both, intraocular pressure (Spearman's correlation coefficient rs = 0.637, p < 0.0001) and proptosis (rs = 0.675, p < 0.0001) correlated strongly with the orbital compartment pressure.

CONCLUSIONS

Needle manometry appears to be a feasible minimally invasive instrument to directly measure orbital compartment pressure, showing promises for a more routine application in managing orbital compartment syndrome. The results further suggest that both elevated intraocular pressure and proptosis are valuable indicators for orbital compartment syndrome.