Risk factors for ophthalmic complications in patients with burns

Burn related globe and adnexal trauma at trauma centres

INTRODUCTION

Prompt management of burn-related globe trauma can prevent long term complications. Delays in diagnosis may occur when globe trauma is associated with life-threatening injuries. We aimed to improve the understanding of the epidemiology, acute assessment and management of burns-related globe and adnexal trauma admitted to two trauma centres in Sydney, Australia.

METHOD

Admitted patients with burns-related globe and/or adnexal trauma were retrospectively reviewed at Royal North Shore Hospital (RNSH) and Royal Prince Alfred Hospital (RPAH) between January 2015 and December 2019. The International Classification of Disease, Tenth Revision codes was used to search and identify patients. Medical records were reviewed to extract data on demographics, injuries, ocular examination and ophthalmology involvement.

RESULTS

Over the 5-years, 101 patients with globe and/or adnexal burns-related trauma were admitted to RNSH or RPAH. Median age was 37years. Most patients were male (76%) and were injured while at home or work (74%). Patients with chemical exposure were more likely to have globe trauma (100% vs 72%, p < 0.001) and severe globe trauma (54% vs 32%, p = 0.028). On initial review by emergency staff, 14 patients were not referred to ophthalmology, of these there were 2 patients where the diagnosis was delayed.

CONCLUSION

Globe trauma is common in patients with chemical exposure. Thorough ocular assessment within the acute setting is vital to diagnose globe trauma. We investigated hospitals with specialised burn staff, further research is required to understand the management of globe trauma in hospitals without such resources.

SYNOPSIS

Chemicals in household-products can cause severe globe trauma. Globe trauma can occur alongside large burns leading to delay in its diagnosis and management. Ophthalmology can assist in the early diagnosis and management of globe trauma.

Fibrin-Plasma Rich in Growth Factors Membrane for the Treatment of a Rabbit Alkali-Burn Lesion

The purpose of this work is to describe the use of Fibrin-Plasma Rich in Growth Factors (PRGF) membranes for the treatment of a rabbit alkali-burn lesion. For this purpose, an alkali-burn lesion was induced in 15 rabbits. A week later, clinical events were evaluated and rabbits were divided into five treatment groups: rabbits treated with medical treatment, with a fibrin-PRGF membrane cultured with autologous or heterologous rabbit Limbal Epithelial Progenitor Cells (LEPCs), with a fibrin-PRGF membrane in a Simple Limbal Epithelial Transplantation and with a fibrin-PRGF membrane without cultured LEPCs. After 40 days of follow-up, corneas were subjected to histochemical examination and immunostaining against corneal or conjunctival markers. Seven days after alkali-burn lesion, it was observed that rabbits showed opaque cornea, new blood vessels across the limbus penetrating the cornea and epithelial defects. At the end of the follow-up period, an improvement of the clinical parameters analyzed was observed in transplanted rabbits. However, only rabbits transplanted with cultured LEPCs were positive for corneal markers. Otherwise, rabbits in the other three groups showed positive staining against conjunctival markers. In conclusion, fibrin-PRGF membrane improved the chemically induced lesions. Nonetheless, only fibrin-PRGF membranes cultured with rabbit LEPCs were able to restore the corneal surface.

Ocular surface characteristics and colonization in a burn center: A prospective cohort study

We aimed to evaluate the characteristics and colonization by pathogenic microorganisms of the ocular surface in patients in a burn center and to determine their association with sedation, mechanical ventilation, and periocular burn. We prospectively evaluated 40 patients during an eight-month period. Five evaluations where performed, at baseline and weekly on four more occasions or until hospital discharge or death. On each visit, we assessed periocular burn, lid position, Bell's phenomenon, Schirmer's test, presence of chemosis, conjunctival hyperemia, and exposure keratopathy; conjunctival fornix swabs were taken for microbiology culture. Also, we documented the level of sedation, mechanical ventilation status, and systemic and ocular treatment. Absent Bell's phenomenon and chemosis were significantly different at baseline in patients under mechanical ventilation, sedation, and in those with periocular burn. The cumulative incidence of exposure keratopathy was 22.5% and the cumulative incidence of ocular surface colonization by pathogenic microorganisms was 32.5%. Both outcomes were associated with mechanical ventilation and periocular burn. The most frequent pathogenic microorganisms in the ocular surface were Candida parapsilosis, Acinetobacter baumanii, and Pseudomonas aeuroginosa. We did not observe any case of persistent epithelial defect, infectious keratitis, corneal perforation or corneal opacity in this cohort. Results from our study may benefit future patients by allowing better risk stratification and treatment strategies for the ocular surface care in burn units.

Acute surgical vs non-surgical management for ocular and peri-ocular burns: a systematic review and meta-analysis

Background

Burn-related injury to the face involving the structures of the eyes, eyelids, eyelashes, and/or eyebrows could result in multiple reconstructive procedures to improve functional and cosmetic outcomes, and correct complications following poor acute phase management. The objective of this article was to evaluate if non-surgical or surgical interventions are best for acute management of ocular and/or peri-ocular burns.

Methods

This systematic review and meta-analysis compared 272 surgical to 535 non-surgical interventions within 1 month of patients suffering burn-related injuries to 465 eyes, 253 eyelids, 90 eyelashes, and 0 eyebrows and evaluated associated outcomes and complications. The PubMed, Embase, Cochrane Library, Web of Science, and Scopus databases were systematically and independently searched. Patient and clinical characteristics, surgical and medical interventions, outcomes, and complications were recorded.

Results

Eight of the 14,927 studies queried for this study were eligible for the systematic review and meta-analysis, with results from 33 of the possible 58 outcomes and complications using Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) and Cochrane guidelines. Surgery was associated with standard mean differences (SMD) 0.44 greater visual acuity on follow-up, SMD 1.63 mm shorter epithelial defect diameters on follow-up, SMD 1.55 mm greater changes in epithelial diameters from baseline, SMD 1.17 mm² smaller epithelial defect areas on follow-up, SMD 1.37 mm² greater changes in epithelial defect areas from baseline, risk ratios (RR) 1.22 greater numbers of healed epithelial defects, RR 11.17 more keratitis infections, and a 2.2 greater reduction in limbal ischemia compared to no surgical intervention.

Conclusions

This systematic review and meta-analysis found that compared to non-surgical interventions, acute surgical interventions for ocular, eyelid, and/or eyelash burns were found to have greater visual acuity on follow-up, shorter epithelial defect diameters on follow-up, greater changes in epithelial diameters from baseline, smaller epithelial defect areas on follow-up, greater changes in epithelial defect areas from baseline, greater numbers of healed epithelial defects, more keratitis infections, and a greater reduction in limbal ischemia, possibility preventing the need of a future limbal stem cell transplantation.

Risk Factors for Ocular Burn Injuries Requiring Surgery

The surgical management of severe ocular burns is challenging and often associated with variable long-term outcome. The aims of this study were to analyze the clinical course of these injuries and determine the factors associated with the need for surgery. A retrospective medical records review was conducted for patients admitted to the Victorian Adult Burns Services, with ocular burns, from January 2000 to January 2010. One hundred and twenty-nine patients were admitted with ocular burns, of which 17 (13.2%) required surgery. The most common indication for surgery was ectropion (n = 9) and the most frequent procedure was full-thickness skin grafts to the eyelids (n = 10). Almost all patients managed surgically developed late ocular complications, the most frequent being visual loss and recurrent ectropion (n = 7 each). Patients undergoing surgery had a longer length of hospital stay (median [interquartile range] 40 [12-90] vs 12 [4-29.5] days; P = .004) and larger TBSA burned (median [interquartile range] 20 [10-60] vs 8 [4-20]; P = .011). Factors associated with the need for surgery included flame burns, periorbital edema, visual loss on presentation, increasing severity of eyelid and facial burns, severe corneal injury, as well as lagophthalmos, ectropion, and microbial keratitis (P < .05). Although only a minority required surgery, these patients often require multiple procedures and develop long-term ocular morbidity.

Early and late complications of ocular burn injuries

BACKGROUND

Ocular involvement in facial burns may lead to significant long-term morbidity. The aims of this study were to analyse the epidemiology, management and outcomes of ocular burn injuries, as well as to identify risk factors for developing early and late ocular complications.

METHODS

A retrospective medical chart review was conducted for 125 patients with ocular burns who were admitted to the Victorian Adult Burns Service (VABS), from November 2000 to January 2010. Univariate analyses was utilised to identify demographic and injury related variables associated with early and late complications.

RESULTS

The majority of patients were male (n=101, 80.8%), and the mean (range) age was 40.7 (15-86) years. The most common mechanism was flame burns (n=77, 61.6%), and most were accidental (n=114, 91.2%). Early ocular complications occurred in 50 (40.0% [95% CI: 31.3%-49.1%]) patients, with the commonest being visual loss (n=39, 31.2%). Chemical burns, ocular discomfort, peri-orbital oedema, corneal injury, as well as eyelid and facial burns of increasing severity were associated with developing an early complication. Late ocular complications occurred in 19 (15.2% [95% CI: 9.4%-22.7%]) patients, with visual loss being the most frequent (n=13, 10.4%). Chemical burns, ocular discomfort, corneal injury of increasing severity, visual loss on presentation, ectropion, as well as eyelid burns of increasing depth were associated with late morbidity.

CONCLUSION

Chemical burns, ocular discomfort, as well as corneal injury and eyelid burns of increasing severity were risk factors for both early and late ocular complications.

LEVEL OF EVIDENCE

III (retrospective comparative study).

Virulence properties of multidrug resistant ocular isolates of Acinetobacter baumannii

PURPOSE

Acinetobacter (A.) baumannii is an opportunistic pathogen and has been reported as a causative agent of ocular infections. The aim of this study is to identify virulence properties (biofilm formation, adhesion, invasion and cytotoxicity) and antibiotic resistance among A. baumannii isolates recovered from the eye.

MATERIALS AND METHODS

The Microscan Walk-Away®, an automated bacterial identification and susceptibility testing system was used to determine antibiotic resistance. Clonal relatedness was assessed by Pulsed-field gel electrophoresis (PFGE) and plasmid profile analysis. Conjugation experiments were carried out to determine the transfer of antibiotic resistance genes and PCR was used to confirm gene transfer. Virulence properties of the isolates were determined by biofilm formation using crystal violet and immunofluorescence staining, adherence and internalization using cultured corneal epithelial cells, and cytotoxicity by TUNEL-staining and LDH release assays.

RESULTS

All ocular isolates (n = 12) exhibited multidrug resistant (MDR) phenotype and one of the isolate (AB12) was resistant to 18 antibiotics (β-lactam, aminoglycosides, tetracycline, chloramphenicol and quinolones). The plasmid profile analysis showed the presence of multiple plasmids in each isolate and a total of 10 different profiles were observed. However, PFGE analysis was more discriminatory which revealed 12 distinct genotypes. Antibiotic resistance (tetracycline and quinolone) was transferable from the isolate AB12 to a recipient Escherichia coli J53. Ten isolates were strong biofilm producers and the remaining two (AB5 and AB7) were moderate producers. All isolates demonstrated adherence and invasive properties towards HCECs. A similar trend was observed in their ability to cause cell death and toxicity.

CONCLUSIONS

Our results indicate that ocular isolates of A. baumannii are biofilm producers and adherent and invasive to corneal epithelium, a first step in the pathogenesis of ocular infection. In addition, they demonstrated plasmid-mediated transfer of MDR traits making them a reservoir of resistance genes at ocular surface.

Severe burn injury, burn shock, and smoke inhalation injury in small animals. Part 2: diagnosis, therapy, complications, and prognosis

OBJECTIVE

To review the evaluation and treatment of patients suffering from severe burn injury (SBI), burn shock, and smoke inhalation injury. Potential complications and prognosis associated with SBI are also discussed.

DIAGNOSIS

Diagnosis of burn injury and burn shock is based on patient history and clinical presentation. Superficial burn wounds may not be readily apparent for the first 48 h whereas more severe wounds will be evident at presentation. Patients are diagnosed with local or SBI by estimating total body surface area involved using the 'Rule of Nines' or the Lund-Browder chart adapted from the human literature.

THERAPY

Patients suffering from SBI require immediate and aggressive fluid therapy. Burn wounds require prompt cooling to prevent progressive tissue damage. Due to significant pain associated with burn wounds and therapeutic procedures, multimodal analgesia is recommended. Daily wound management including hydrotherapy, topical medications, and early wound excision and grafting is necessary with SBI.

COMPLICATIONS

There are numerous complications associated with SBI. The most common complications include infections, hypothermia, intra-abdominal hypertension, and abdominal compartment syndrome.

PROGNOSIS

The prognosis of SBI in domestic animals is unknown. Based on information derived from human literature, patients with SBI and concomitant smoke inhalation likely have a worse prognosis than those with SBI or smoke inhalation alone.

Intravitreal tigecycline treatment in experimental Acinetobacter baumannii endophthalmitis

PURPOSE

To investigate the clinical and microbiological effectivity of intravitreal tigecycline in an experimental rabbit endophthalmitis model caused by imipenem resistant Acinetobacter baumannii.

MATERIALS AND METHODS

Forty-eight eyes of 24 New Zealand white albino rabbits were divided into six groups (n=8 in each). The right eyes were divided into three groups and defined as infected group; left eyes were divided into three groups and defined as uninfected group. Infected group received 0.1 ml intravitreal A. baumannii suspension. Twenty-four hours after bacterial inoculation, group 1 received 1 mg/0.1 ml tigecycline and group 2 received 0.5 mg/0.1 ml tigecycline. Group 3 eyes received no treatment. In group 4, 0.1 ml of saline solution was injected. Groups 5 and 6 were received intravitreal tigecycline injection of 1 mg/0.1 ml and 0.5 mg/0.1 ml respectively. The eyes were enucleated for histopathological evaluation on the sixth day. Clinical and histological scoring systems were used to evaluate clinical and histological severity of the intraocular infection.

RESULTS

The mean clinical scores of the six groups at the sixth day were 11±1.92, 12.4±6.2, 8.5±2.7, 0, 3±1.3, and 3±1.4 respectively. Mean histopathological scores were 7.8±2.8, 7.0±1.5, 5.6±1.4, 0, 0, and 0 respectively. There was no significant difference in mean clinical and histopathological scores of infected group (groups 1, 2 and 3). There was significant difference in mean clinical scores of groups 5 and 6 compared with group 4. Groups 4, 5 and 6 showed normal histological structure in histopathological evaluation and showed no significant difference. Microbiological cure was achieved in all infected eyes.

CONCLUSIONS

Experimental rabbit endophthalmitis model caused by imipenem resistant A. baumannii was microbiologically cured by intravitreal tigecycline injection. However, a hypersensitivity-like reaction due to intravitreal application of tigecycline limits the use of this antimicrobial agent in A. baumannii endophthalmitis.

Evolving changes in the management of burns and environmental injuries

Burns and environmental injuries are common as primary or secondary problems in survivors of natural disasters, terrorist incidents, and combat operations. In recent years, intensive military medical experience has resulted in substantial progress in treatment of these important problems. This article reviews practical applications of this new knowledge.