Tympanic Membrane Rupture Research Articles

Efficacy study of hyperbaric oxygen therapy for the treatment of central retinal artery occlusion: a systematic review

Central Retinal Artery Occlusion (CRAO) is a rare ophthalmology emergency caused by central retinal artery embolism. Many CRAO management strategies exist. However, no treatment has consistently improved visual outcomes following CRAO. These medicines have many negative effects and unclear efficacy. HBOT has been considered for CRAO management. HBOT may minimize ischemia damage between CRAO and retinal artery recanalization, which normally occurs within 72 hours.9 There is continuous disagreement about whether this treatment procedure achieves the desired visual target. The method use is PRISMA principles were followed for a systematic review. This systematic review examines HBOT's efficacy in CRAO. The search terms were “Hyperbaric Oxygen Therapy” (“HBOT”) and “Central Retinal Artery Occlusion” (“CRAO”). The 5 investigations were primarily cohort retrospective. Four studies found no link between onset-to-HBOT time and visual outcome, two found no correlation between HBOT session and VA improvement, and three found no correlation between first therapy before HBOT and VA improvement. All said this therapy produced side effects. The conclusion is in this study is more investigations showed no significant link between onset-to-HBOT time, initial treatment before HBOT, and VA improvement. HBOT can produce barotrauma, ear pain, tympanic membrane rupture, and central nervous system oxygen poisoning seizures, so these must be considered.

Evaluation of canine tympanic membrane integrity using positive contrast computed tomography canalography.

The assessment of the integrity of the tympanic membrane (TM) can be a diagnostic challenge in patients with otitis externa and/or otitis media (OM) under an otoscopic examination. In computed tomography (CT), the TM is not always visualized. However, a positive contrast canalography using conventional radiography has been previously described to evaluate the TM integrity. This single-center study aimed to describe the positive contrast canalography technique in CT and its usefulness in identifying TM integrity in 11 dogs. Dogs with clinical signs of ear disease underwent CT canalography following a systematic protocol. The presence of contrast medium and contrast homogeneity within the tympanic cavity was assessed, confirming TM rupture when contrast medium was present in the tympanic cavity. CT canalography was performed in 16 ears, and in 7 of the 16 ears (44%), there was a contrast in the tympanic cavity, confirming TM rupture (positive CT canalography result). In two of the seven cases (29%), rupture of the TM was identified in both otoscopic and CT canalography. In the remaining five of the seven (71%) positive CT canalography results, tympanic membrane rupture was identified only by CT canalography. In conclusion, a positive contrast CT canalography is a complementary and safe technique to assess TM integrity, with a potentially higher sensitivity than otoscopic examination for the diagnosis of TM rupture in dogs.

Relationship of Hearing Loss and Tympanic Membrane Perforation Characteristics in Chronic Suppurative Otitis Media Patients.

Objective The objective of this study is to assess the relationship between the site of tympanic membrane (TM) perforation and the type and degree of hearing impairment. The secondary objectivewas to compare the duration of the disease and the degree of hearing loss. Study design This is a prospective observational study. Place and duration of the study This study was carried out in the Department of Otolaryngology/Head and Neck Surgery at the Pakistan Institute of Medical Sciences, Islamabad, from May 2021 to April 2022. Patients and methods Of all the screened patients, 77 fulfilled the inclusion criteria. Patients aged 10-40 years with inactive mucosal chronic otitis media and unilateral perforation in one quadrant were included. The site of TM rupture was observed, and audiometric analysis was performed. Results The mean age of participants was 25 ± 8.61 years, with a preponderance of the female gender (57.1%). A total of 32 (41.6%), 19 (24.7%), 19 (24.7%), and seven(9.1%) perforations involved posterosuperior, anterosuperior, anteroinferior, and posteroinferior quadrants respectively. Conductive, mixed, and sensorineural hearing loss was found in 52 (67.5%), 18 (23.4%), and seven (9.1%) cases, respectively. Of all the subjects, 13 (16.9%) had the disease for < one year, 39(50.6%) for one to five years, 17 (22.1%) for five to 10 years, and eight (10.4%) for > 10 years. There was a statistically significant association between the degree of hearing loss and the site of perforation. No significant association was found between the site of perforation and thetype of hearing loss. Duration of disease and degree of hearing loss also had no significant association. Conclusion The extent of hearing loss was found to be directly influenced by the anatomical site of perforation, with the posterosuperior quadrant perforation producing the greatest degree of impairment.

Incidence and Management of Facial Paralysis After Skull Base Trauma, an Administrative Database Study.

Report the incidence of and treatment patterns for facial nerve palsy after skull base fracture. Retrospective cohort study. IBM MarketScan Commercial Database (2006-2019). Human subjects with skull base fracture, per International Classification of Diseases-9th and 10th Revisions-Clinical Modification diagnosis codes. The primary outcomes were the incidence and median time to facial nerve palsy diagnosis within 30 days of skull base fracture. Secondary outcomes were treatments (corticosteroids, antivirals, facial nerve decompression, botulinum toxin, and facial reanimation), demographics, and rates of hearing loss, vertigo, tympanic membrane rupture, cerebrospinal fluid leak, comorbidities, and loss of consciousness. The 30-day incidence of facial nerve palsy after skull base trauma was 1.0% (738 of 72,273 patients). The median (95% confidence interval [CI]) time to diagnosis was 6 (6-7) days, and only 22.9% were diagnosed within 1 day. There were significantly higher rates (risk difference, 95% CI) of hearing loss (26%, 22-29%), tympanic membrane rupture (6.3%, 4.5-8.1%), cerebrospinal fluid leak (6.4%, 4.5-8.3%), comorbidity (14%, 10.4-17.6%), and loss of consciousness (24.3%, 20.7-27.9%). Loss of consciousness was associated with longer median (95% CI) time to facial nerve palsy diagnosis: 10 (9-10) days. Corticosteroids were the most common treatment but only reported for less than one-third of patients. Only eight patients underwent facial nerve decompression. Facial nerve palsy after skull base fracture is associated with higher comorbidity, and the diagnosis is often delayed. Few patients were treated with surgery, and there are inconsistencies in the types and timing of treatments.

Incidence and Epidemiology of Traumatic Tympanic Membrane Rupture: A National Trauma Data Bank Analysis.

The incidence of traumatic tympanic membrane rupture (TTMR) has increased over recent decades. The association of certain external injury causes and bone fracture patterns with TTMR is anecdotal. It has been suggested that a diagnosis of TTMR may be missed during the acute trauma admission. The authors sought to evaluate the incidence of TTMR according to external injury cause and evaluate the association of skull fracture patterns with TTMR using a national trauma database. A cross-sectional analysis of trauma encounters was conducted using the National Trauma Data Bank (NTDB) from 2008 to 2015. Demographic and injury data were abstracted. Poisson regression was used to determine the incidence rate ratios of tympanic membrane rupture by external injury cause and logistic regression was used to estimate odds ratios (OR) of TTMR by skull fracture type. A total of 8214 patients were identified with TTMR during acute admission. The majority were on average 30 years old, 76% male, 71% White, had a mean Injury Severity Score of 14, and 42% were admitted to level I centers. The incidence rate ratio was only higher in lightning related injuries [5.262; 95% confidence interval (CI): 4.194-6.602] when using those caused by explosives as a reference. Basilar skull (OR: 12.95; 95% CI: 12.095-12.866) and cranial vault (OR: 2.938; 95% CI: 2.647-3.260) fractures were most associated with TTMR. The high incidence TTMR in association with certain external causes of injury and types of skull fractures should drive screening in the acute setting in order to increase detection and reduce morbidity from missed injuries.

Incidence and Patterns of Firework-related Injuries: An Explosion in 2020

Introduction: Approximately 10,000 Americans are treated annually for firework-related injuries. In 2020, US police organizations reported an increased number of firework-related calls. Furthermore, because of the COVID pandemic, many major firework displays were cancelled, and celebrants shifted to smaller, distributed events. We examine if there was a concomitant increase in firework-related injuries. Methods: We performed a retrospective review of patients who presented to our urban level 1 trauma center between January 1st, 2015 and July 31st, 2020 with firework-related injuries. Patients were identified from our trauma registry and emergency department records. Charts were reviewed for patient demographics, injuries, procedures performed, and mortality. Patients were grouped by date of presentation and descriptive statistics were derived. Results: We identified 66 patients injured during the study period. The median age was 23 and 91% were male. The incidence was stable over the study period except for a dramatic rise in 2020, when half of all injuries occurred. The most common injuries were fingers (74%), hand and wrist (48%), burns (47%), and ocular (42%). 26% demonstrated the triad of injury to hand or fingers, eyes, and tympanic membrane rupture. 63% needed amputation of at least one digit. 18% required amputation of the hand. Conclusion: There has been a steep increase in the number of firework-related trauma in 2020. These injuries continue to cause serious, lifelong disability. Although the recent spike may have been driven by a combination of transient social conditions, this data should inform increased efforts at prevention and research into causative factors.

COTTON SWAB TODAY, BRAIN ABSCESS TOMORROW

TOPIC: Critical Care TYPE: Medical Student/Resident Case Reports INTRODUCTION: Brain abscess usually occurs as a result of predisposing factors such as HIV or other immunosuppressive state, systemic infection, or disruption in the protective barrier surrounding the brain, including trauma, operative procedures, mastoiditis, sinusitis or dental procedure. We report a very unique case of subdural empyema and abscess with associated mastoiditis and sinus thrombosis in the setting of a retained cotton swab. CASE PRESENTATION: Patient is a 47-year-old male with a past medical history of hypertension who presented with left arm weakness and numbness and left-sided facial droop. Computed Tomography (CT) of the brain showed an ill-defined hypodense 3.4 cm posterior right parietal lobe mass. Magnetic Resonance Imaging (MRI) was significant for an acute/subacute 2.8 x 3.1x 2 cm subdural empyema with extra-axial mass with smooth ring enhancement with associated thrombosis of the right transverse and sigmoid sinuses with right mastoiditis and medial erosion of air cells. A chronic left occipital abscess was also visualized on MRI with contrast. The patient was started on ceftriaxone, flagyl and vancomycin for empiric coverage and was managed in the ICU for septic shock. A decision was made not to anticoagulate due to the high risk of bleeding with an infectious etiology. HIV testing was negative. The patient was taken for right craniectomy with empyema evacuation and tympanomastoidectomy. During the surgical procedure, a posterior canal incision was made to the mastoid cortex and a cotton swab was found and retracted; it was attached to granulation tissue coming through the ear drum. Pathology confirmed cotton material representing a cotton swab. Gram stain showed gram positive cocci in pairs and surgical culture grew Anaerococcus species. DISCUSSION: The most common organism occurring in cases of contiguous spread of middle ear, mastoid, or sinus infection are streptococcus species, however, staphlococcal and polymicrobial abscesses caused by anaerobes, gram negative bacilli, and uncultured bacteria have been reported. Anaerococcus are gram positive strictly anaerobic bacteria that can occur in pairs, tetrads, or short chains. While many species are found as part of the normal flora of skin, oral cavity or gut, specimens isolated from abscesses have been reported. This is the first case to our knowledge of subdural empyema and abscess associated sinus thrombosis in the setting of retained cotton swab and isolation of Anaerococcus species. CONCLUSIONS: Warnings against the using cottons swabs in the ear canal exist due to the risk of foreign body, worsening cerumen impaction, and tympanic membrane rupture. Our case highlights the risk of cotton swab use in the ear. Physicians should be aware that resulting complications can include subdural empyema and abscess associated with transverse and sigmoid sinus thrombosis. REFERENCE #1: Brouwer MC, Tunkel AR, McKhann GM 2nd, van de Beek D. Brain abscess. N Engl J Med. 2014 Jul 31;371(5):447-56. doi: 10.1056/NEJMra1301635. PMID: 25075836. REFERENCE #2: Masalma MA, Lonjon M, Richet H, Dufour H, Roche P-H, Drancourt M, et al. Metagenomic Analysis of Brain Abscesses Identifies Specific Bacterial Associations. Clinical Infectious Diseases. 2011;54(2):202–10. REFERENCE #3: Murphy EC, Frick I-M. Gram-positive anaerobic cocci – commensals and opportunistic pathogens. FEMS Microbiology Reviews. 2013;37(4):520–53. DISCLOSURES: No relevant relationships by Benjamin Carmel, source=Web Response No relevant relationships by Mauricio Danckers, source=Web Response No relevant relationships by Davide Fox, source=Web Response No relevant relationships by Daniel Heller, source=Web Response No relevant relationships by Vijay Srinivasan, source=Web Response

TOTAL EAR CANAL ABLATION AND LATERAL BULLA OSTEOTOMY (TECA-LBO) IN ATLANTIC HARBOR SEALS (PHOCA VITULINA CONCOLOR) FOR SUCCESSFUL SURGICAL MANAGEMENT OF OTITIS MEDIA.

Chronic, severe otitis media was diagnosed in four Atlantic harbor seals (Phoca vitulina concolor), three of which were stranded animals undergoing rehabilitation. All seals presented with unilateral purulent aural discharge that would intermittently recur despite prolonged topical and systemic antimicrobial therapy. Aerobic culture from aural discharge isolated multidrug-resistant organisms in all seals, including Pseudomonas aeruginosa, Staphylococcus pseudintermedius, Klebsiella pneumoniae, and/or Enterococcus faecalis. Computed tomography was used in three cases to confirm otitis media and positive contrast ear canalography was used in one case to confirm tympanic membrane rupture. Given the persistent nature of otitis, surgical intervention in the form of a total ear canal ablation and lateral bulla osteotomy (TECA-LBO) was indicated. Surgery was successful in achieving complete clinical resolution of otitis in all seals. Postoperative complications included temporary unilateral paralysis of the left nare (2/4) and a transient left ptosis (1/4). Partial to complete surgical site dehiscence occurred in all cases; however, complete healing was achieved by second intention in 60 d or less. One rehabilitated seal was fitted with a satellite tag that confirmed normal swimming and diving patterns post release. In harbor seals, TECA-LBO can be performed safely to treat persistent cases of otitis media and should be considered in cases of chronic otitis that are not responsive to medical management.

Assessment of auditory and vestibular damage in a mouse model after single and triple blast exposures

The use of explosive devices in war and terrorism has increased exposure to concussive blasts among both military personnel and civilians, which can cause permanent hearing and balance deficits that adversely affect survivors’ quality of life. Significant knowledge gaps on the underlying etiology of blast-induced hearing loss and balance disorders remain, especially with regard to the effect of blast exposure on the vestibular system, the impact of multiple blast exposures, and long-term recovery. To address this, we investigated the effects of blast exposure on the inner ear using a mouse model in conjunction with a high-fidelity blast simulator. Anesthetized animals were subjected to single or triple blast exposures, and physiological measurements and tissue were collected over the course of recovery for up to 180 days. Auditory brainstem responses (ABRs) indicated significantly elevated thresholds across multiple frequencies. Limited recovery was observed at low frequencies in single-blasted mice. Distortion product otoacoustic emissions (DPOAEs) were initially absent in all blast-exposed mice, but low-amplitude DPOAEs could be detected at low frequencies in some single-blast mice by 30 days post-blast, and in some triple-blast mice at 180 days post-blast. All blast-exposed mice showed signs of tympanic membrane (TM) rupture immediately following exposure and loss of outer hair cells (OHCs) in the basal cochlear turn. In contrast, the number of inner hair cells (IHCs) and spiral ganglion neurons was unchanged following blast-exposure. A significant reduction in IHC pre-synaptic puncta was observed in the upper turns of blast-exposed cochleae. Finally, we found no significant loss of utricular hair cells or changes in vestibular function as assessed by vestibular evoked potentials. Our results suggest that (1) blast exposure can cause severe, long-term hearing loss which may be partially due to slow TM healing or altered mechanical properties of healed TMs, (2) traumatic levels of sound can still reach the inner ear and cause basal OHC loss despite middle ear dysfunction caused by TM rupture, (3) blast exposure may result in synaptopathy in humans, and (4) balance deficits after blast exposure may be primarily due to traumatic brain injury, rather than damage to the peripheral vestibular system.

Prevention of middle ear barotrauma with oxymetazoline/fluticasone treatment

Prevention of middle ear barotrauma with oxymetazoline/fluticasone treatment Middle ear barotrauma (MEB) is a common complication of hyperbaric oxygen (HBO2) therapy. It has been reported in more than 40% of HBO2 treatments and can interrupt the sequence of HBO2. MEB may lead to pain, tympanic membrane rupture, and even hearing loss.The aim of this study was to determine if pretreatment with intranasal fluticasone and oxymetazoline affected the incidence of MEB. We conducted a retrospective chart review of subjects undergoing HBO2 at our institution between February 1, 2014, and May 31, 2019. Subjects in the fluticasone/oxymetazoline (FOT) treatment group used intranasal fluticasone 50 mcg two times per day and oxymetazoline 0.05% one spray two times per day beginning 48 hours prior to initial HBO2. Oxymetazoline was discontinued after four days. Fluticasone was continued for the duration of HBO2 therapy. A total of 154 unique subjects underwent 5,683 HBO2 treatments: 39 unique subjects in the FOT group underwent 1,501 HBO2; 115 unique subjects in the nFOT (no oxymetazoline or fluticasone treatment) group underwent 4,182 HBO2 treatments. The incidence of MEB was 15.4% in the FOT group and 16.2% in the nFOT group. This was not a statistically significant difference (OR = 0.77; p = 0.636). Treatment pressure, age over 65 years, male sex, and BMI were not associated with a difference in MEB incidence. In summary, pretreatment with intranasal oxymetazoline and fluticasone in patients undergoing HBO2 did not significantly reduce MEB. More investigation with larger numbers of participants and prospective studies could further clarify this issue.

Otologic Injuries Secondary to Explosive Attack.

The frequency of injuries secondary to terrorist attack explosion is globally increasing. Like any other country, our country experienced multiple suicide bombings in recent years. Otologic injuries may be observed after these kinds of attacks. Considering otologic complaints are well known medical results of explosion attacks, routine otologic evaluation in the first examining hospital-even in case of no relevant complaint- is crucial for establishing causal relation in following forensic medicine evaluation. In this study, 33 cases from 6 suicide bomber attacks in 4 different incidents that happened in Turkey were evaluated for otologic injuries. Two out of three patients were not evaluated for otologic injuries in their first hospital visit. It was considered that 8 cases had a loss of hearing and 9 cases had tympanic membrane rupture secondary to the explosion. Complaints such as hearing loss and tinnitus very often after a bomb attack, we saw that 22 of 33 included patients did not have an ear nose, and throat examination at the time of the incident. In this kind of attack, there can be various life-threatening injuries and therefore relatively less important evaluations such as ENT examination can often be overlooked.

Risk of Middle Ear Complications in Intubated Patients on Mechanical Ventilation Versus Non Intubated

Patients on mechanical ventilation through artificial airway intubation may compromise their normal eustachian tube function and equilibration of middle ear pressures. Aim of the study is to evaluate the risk of middle ear complications in the positive pressure air-filled middle ears. A prospective study of patients findings with a different diagnosis, who were admitted for more than ten days duration in Intensive Care Units (ICU) in different hospitals of Benghazi city over a period of six months . Head injury and tympanic membrane rupture were excluded in this study. The approach that had been used was otoscope examination of the ears of 120 ICU patients by an ENT specialist, Results: (the age ranged from 14 days to 75 years). The comparison between two groups of intubated (40 cases) and non-intubated (80 cases) patients was performed. Among 40 mechanically ventilated patients, 37 patients (92.5%) developed middle ear complications. Whereas only nine out of 80 patients in non intubated group(11.3%) were developed middle ear complications. These results suggest that all intubated patients on mechanical ventilation for more than ten days should be routinely examined, and subjected for portable tympanometry evaluation of the middle ear. They may need tympanostomy tubes insertion.

Tympanic Membrane Rupture During Stereotaxic Surgery Disturbs the Normal Feeding Behavior in Rats.

Stereotactic surgery is a widely used procedure in neuroscience research to study the brain’s regulation of feeding behavior. In line with this notion, this study aims to assess how food consumption and feeding patterns are affected in response to the use of auditory bars that preserve or damage the tympanic membrane during stereotactic surgery. Our previous observations led us to hypothesize that the traumatic tympanic membrane rupture affects food intake and feeding patterns in rats undergoing stereotactic procedures. Thereby, female and male rats were cannulated in the third ventricle (3V) using both types of auditory bars. Post-surgical pain was assessed using the grimace scale. Food intake, meal patterns and weight gain or loss were analyzed for 5–7 consecutive days after surgery. Normal food intake, increased body weight and regular meal patterns were observed from postoperative day 2 when the stereotactic procedure was performed using auditory bars that maintain the integrity of the tympanic membrane. However, tympanic membrane rupture prevented the expected recovery of food intake and body weight. This effect was accompanied by an alteration in eating patterns, which was persistent over 7 days of recovery. Thus, tympanic membrane preservation during surgery is necessary to evaluate short-term feeding patterns. This study demonstrates auditory bars that do not damage the tympanic membrane should be used when performing stereotactic surgery for subsequent analysis of rat behavior.

Evaluation of a Model of Long-Term Middle Ear Catheterization for Repeat Infusion Administration and Cochlear Hair Cell Injury in Guinea Pigs.

Middle ear administration has numerous applications, including antibiotherapy and gene therapy, and is increasingly used to target the auditory and vestibular systems. In animal studies, investigating repeated exposure that mimics clinical dosing regimens has remained a challenge due to the lack of suitable models. Intratympanic injections are not suitable for long-term studies due to the increased risk related to tympanic membrane rupture or scarring and repeat anesthesia events. Surgical models of middle ear catheterization previously used have not been reliable for longer than 4 weeks, resulted in elevated stress levels, and have been associated with significant changes related to the surgery and/or the presence of the catheter such as local trauma and inflammatory and degenerative processes. These complications cause decreased hearing/deafness and greatly diminish the value and accuracy of ototoxicity studies. We describe here a procedure that permits repeat dosing into the middle ear of guinea pigs and can be used to produce a model of aminoglycoside-induced hair cell injury. The innocuity of the procedures and the efficacy of the ototoxicity model were confirmed using auditory brain stem response assessment, histopathological evaluation, and cytocochleograms. Procedure-related changes were limited to minimal inflammation in the middle ear.

The Development of a Tympanic Membrane Model and Probabilistic Dose-Response Risk Assessment of Rupture Because of Blast.

There is no dose-response model available for the assessment of the risk of tympanic membrane rupture (TMR), commonly known as eardrum rupture, from exposures to blast from nonlethal flashbangs, which can occur concurrently with temporary threshold shift. Therefore, the objective of this work was to develop a fast-running, lumped parameter model of the tympanic membrane (TM) with probabilistic dose-dependent prediction of injury risk. The lumped parameter model was first benchmarked with a finite element model of the middle ear. To develop the dose-response curves, TMR data from a historic cadaver study were utilized. From these data, the binary probability response was constructed and logistic regression was applied to generate the respective dose-response curves at moderate and severe eardrum rupture severity. Hosmer-Lemeshow statistical and receiver operation characteristic analyses showed that maximum stored TM energy was the overall best dose metric or injury correlate when compared with total work and peak TM pressure. Dose-response curves are needed for probabilistic risk assessments of unintended effects like TMR. For increased functionality, the lumped parameter model was packaged as a software library that predicts eardrum rupture for a given blast loading condition.

Energy based model of the human Ear canal and tympanic membrane for sound transmission

The objective of this paper is to present a unique energy based model of the human outer ear and the tympanic membrane. The developed model employs the Port Hamiltonian modelling approach. The tympanic membrane is modelled as an Euler-Bernoulli beam. The frequency response of the model at speech frequencies which are significant for sound transmission are found to comparable to existing results in literature. This model can also be used for investigation of tympanic membrane rupture or perforations. Future work will include modelling of the ear canal as horn shaped and inclusion of the angular motion of the tympanic membrane.

LIGHTNING STRIKE: RECOGNITION AND MANAGEMENT

SESSION TITLE: Tuesday Fellows Case Report Posters SESSION TYPE: Fellow Case Report Posters PRESENTED ON: 10/22/2019 01:00 PM - 02:00 PM INTRODUCTION: While lightning strike injuries are uncommon in clinical practice, these cause approximately 100 deaths and 300 injuries a year. Though 66% of the fatalities occur in the first hour due to arrhythmia or respiratory failure, substantial organ dysfunction can occur afterward. These include severe burn complications, deep tissue injury, rhabdomyolysis, seizures, cognitive impairment, otic abnormalities and ophthalmologic injury. Furthermore, 74% of survivors from strikes have permanent disabilities with a wide range of manifestations (1). CASE PRESENTATION: A 21-year-old man working on water hoses near a fire station had a witnessed collapse with prompt initiation of resuscitative efforts. En route to the emergency room and subsequently to the ICU, four tonic-clonic seizures were witnessed. Initial physical examination showed elevated temperature and blood pressure with a normal heart rate, an erythematous serpiginous rash from left head to the opposite foot where it ended in a caustic open wound, unilateral tympanic membrane rupture and pre-retinal macular hemorrhage. Labs demonstrated a leukocytosis, elevated liver enzymes, creatinine, creatinine kinase, and troponin. Electrocardiogram showed sinus arrhythmia without ischemia. Given the constellation of findings, a diagnosis of lightning strike was made. The patient was treated with fluid resuscitation, targeted temperature management and anti-seizure medications. He had numerous early sub-specialty consultations including trauma surgery, neurology, ophthalmology, otolaryngology, and dermatology. He was extubated on hospital day 9 and discharged on hospital day 18 neurologically intact. DISCUSSION: Cardiopulmonary stability is critical to prevent early mortality. The electrical impulse causes synchronous myocardial contraction followed by a variable period of asystole, causing ischemia and arrhythmias. Respiratory arrest is presumed to be a consequence of inhibition of the medullary respiratory center (2). Patients can have extensive, high degree burns that require specialist care. Interventions include aggressive fluid hydration, debridement and topical wound care. Muscle necrosis can lead to compartment syndrome, rhabdomyolysis and kidney injury. The central nervous system effects include autonomic instability, impaired consciousness, amnesia, seizures, tympanic membrane rupture, and ocular hemorrhage. Lasting ocular effects are common as 6% develop cataracts in the first year and a smaller population developing them within 3 years (3). CONCLUSIONS: The chances of a lightning strike are 1 in 500,000, conferring significant morbidity and mortality (1). Most practitioners have minimal experience with these injuries, affecting diagnosis and management. The effect of a lightning strike can damage numerous organ systems making it imperative to recognize different types of dysfunction for treatment of immediate injuries and long-term sequelae. Reference #1: “Lightning | CDC.” Centers for Disease Control and Prevention, Centers for Disease Control and Prevention, www.cdc.gov/disasters/lightning/index.html. Reference #2: Hiestand D, Colice GL. Lightning-strike injury. Journal of Intensive Care Medicine. 1988 Nov;3(6):303-14. Reference #3: Wesner ML, Hickie J. Long-term sequelae of electrical injury. Canadian family physician. 2013 Sep 1;59(9):935-9. DISCLOSURES: No relevant relationships by James Bardwell, source=Web Response No relevant relationships by Bhupinder Natt, source=Web Response No relevant relationships by Alan Nyquist, source=Web Response

The effect of blast overpressure on the mechanical properties of the human tympanic membrane

The rupture of the tympanic membrane (TM) is one of the major indicators for blast injuries due to the vulnerability of TM under exposure to blast overpressure. The mechanical properties of the human TM exhibit a significant change after it is exposed to such a high intensity blast. To date, the published data were obtained from measurement on TM strips cut from a TM following an exposure to blast overpressure. The dissection of a TM for preparation of strip samples can induce secondary damage to the TM and thus potentially lead to data not representative of the blast damage. In this paper, we conduct mechanical testing on the full TM in a human temporal bone. A bulging experiment on the entire TM is carried out on each sample prepared from a temporal bone following the exposure to blast three times at a pressure level slightly below the TM rupture threshold. Using a micro-fringe projection method, the volume displacement is obtained as a function of pressure, and their relationship is modeled in the finite element analysis to determine the mechanical properties of the post-blast human TMs, the results of which are compared with the control TMs without an exposure to the blast. It is found that Young's modulus of human TM decreases by approximately 20% after exposure to multiple blast waves. The results can be used in the human ear simulation models to assist the understanding of the effect of blast overpressure on hearing loss.

Missed injuries in combat casualties: Lessons from Iraq and Afghanistan

IntroductionOnce injured in the battlefield in Iraq and Afghanistan, U.S. and NATO troops receive medical treatment through tiered echelons of care with varying resources, from austere to state-of-the-art. Similar to civilian trauma systems, the aim is to provide rapid and safe patient movement toward definitive management. A consequence of the rapid transfer of patients is the possibility of missed or delayed diagnosis of injuries. With the new injury patterns seen during these conflicts, we aimed to identify and characterize which injuries are missed and what consequences do they have on our troops’ road to recovery. Patients and MethodsA retrospective review of a PI database (established 2007) for consecutively admitted combat casualties was performed between 2007–2013. Baseline patient characteristics, injury year, admitting service, injury type, and subsequent management decisions were categorized and analyzed. ResultsThere were 301 missed injuries (MI) identified in 248 patients. The annual missed injury rate was 25 per 1000 admissions. Missed injuries were associated with a penetrating mechanism (82.7% vs 58.5%, p < 0.001), ICU admission (58.5% vs 27.4%, p < 0.001), higher ISS (median 14 vs 8, p < 0.001), and a longer length of stay (median 3 versus 2 days, p < 0.001). 194 (64.5%) missed injuries led to a change in management, with 68 (22.6%) requiring a surgical procedure. 1.3% of missed injuries were life threatening, 28.2% major and 65.4% minor. The most common injuries were distal extremity fractures (23.9%), followed by spine fractures (13.3%) and traumatic tympanic membrane rupture (12.6%), There were no deaths attributed to a missed injury. DiscussionMissed injuries during combat operations occur on a low but consistent basis. Most injuries are orthopedic in nature and typically occur in critically ill patients admitted to the ICU. It is rare that a missed injury results in a life-threatening condition. ConclusionAs healthcare practitioners prepare for future deployments, this analysis may serve as a resource to focus on frequently missed injuries and possibly improve their detection.

Deletion of genes involved in the ketogluconate metabolism, Entner-Doudoroff pathway, and glucose dehydrogenase increase local and invasive virulence phenotypes in Streptococcus pneumoniae.

Streptococcus pneumoniae displays increased resistance to antibiotic therapy following biofilm formation. A genome-wide search revealed that SP 0320 and SP 0675 (respectively annotated as 5-keto-D-gluconate-5-reductase and glucose dehydrogenase) contain the highest degree of homology to CsgA of Myxococcus xanthus, a signaling factor that promotes cell aggregation and biofilm formation. Single and double SP 0320 and SP 0675 knockout mutants were created in strain BS72; however, no differences were observed in the biofilm-forming phenotypes of mutants compared to the wild type strain. Using the chinchilla model of otitis media and invasive disease, all three mutants exhibited greatly increased virulence compared to the wild type strain (increased pus formation, tympanic membrane rupture, mortality rates). The SP 0320 gene is located in an operon with SP 0317, SP 0318 and SP 0319, which we bioinformatically annotated as being part of the Entner-Doudoroff pathway. Deletion of SP 0317 also resulted in increased mortality in chinchillas; however, mutations in SP 0318 and SP 0319 did not alter the virulence of bacteria compared to the wild type strain. Complementing the SP 0317, SP 0320 and SP 0675 mutant strains reversed the virulence phenotype. We prepared recombinant SP 0317, SP 0318, SP 0320 and SP 0675 proteins and confirmed their functions. These data reveal that disruption of genes involved in the degradation of ketogluconate, the Entner-Doudoroff pathway, and glucose dehydrogenase significantly increase the virulence of bacteria in vivo; two hypothetical models involving virulence triggered by reduced in carbon-flux through the glycolytic pathways are presented.