Improving Outcomes Associated with Prehospital Combat Airway Interventions: An Unrealized Opportunity.

BACKGROUND: Airway obstruction is the second leading cause of potentially survivable death on the battlefield. Assessing outcomes associated with airway interventions is important, and temporal trends can reflect the influence of training, technology, the system of care, and other factors. We assessed mortality among casualties undergoing prehospital airway intervention occurring over the course of combat operations during 2007-2019. METHODS: This is a retrospective analysis of a previously described dataset from the Department of Defense Trauma Registry (DODTR). We included only casualties with documented placement of an endotracheal tube, cricothyrotomy, or supraglottic airway (SGA) in the prehospital setting. RESULTS: Within the DODTR from January 2007 to December 2019, there were 25,849 adult encounters with documentation of any prehospital activity. Within that group, there were 251 documented cricothyrotomies, 1,147 documented intubations, and 35 documented supraglottic airways placed. Cricothyrotomy recipients had a median age of 25. Within this group, the largest proportion were non-North Atlantic Treaty Organization (NATO) military personnel (35%), were injured by explosives (54%), had a median injury severity score (ISS) of 24, and 60% survived to hospital discharge. Intubation recipients had a median age of 24. Within this group, the largest proportion were non-NATO military personnel (37%), were injured by explosives (57%), had a median ISS of 18, and 76% survived to hospital discharge. SGA recipients had a median age of 28. Within this group, the largest proportion were non-NATO military (37%), were injured by firearms (48%), had a median ISS of 25, and 54% survived to hospital discharge. A downward trend existed in the quantity of all procedures performed during the study period. In both unadjusted and adjusted regression models, we identified no year-to-year differences in survival after prehospital cricothyrotomy or SGA placement. In the unadjusted and adjusted models, we noted a decrease in mortality during the 2007-2008 (odds ratio [OR] for death 0.47, 95% CI 0.26-0.86) and an increase from 2012-2013 (OR 2.10, 95% CI 1.09-4.05) for prehospital intubation. CONCLUSION: Mortality among combat casualties undergoing prehospital or emergency department airway interventions showed no sustained change during the study period. These findings suggest that advances in airway resuscitation are necessary to achieve mortality improvements in potentially survivable airway injuries in the prehospital setting.

TCCC Guidelines Comprehensive Review and Edits 2020: TCCC Guidelines Change 20-05 01 November 2020.

Based on careful review of the Tactical Combat Casualty Care (TCCC) Guidelines, the authors developed a list of proposed changes and edits for inclusion in a comprehensive change proposal. To be included in the proposal, individual changes had to meet at least one of three criteria: 1. The change was primarily tactical, operational, or educational rather than clinical in nature. 2. The change was a minor modification to the language of an existing TCCC Guideline. 3. The change, though clinical, was straightforward and noncontentious. The authors initially presented their list to the TCCC Collaboration Group for review at the 11 August 2020 online virtual meeting of the Committee on Tactical Combat Casualty Care (CoTCCC). Based on discussions during the virtual meeting and following revisions, a second presentation of guideline modifications was presented during the CoTCCC session of the online virtual Defense Committee on Trauma meeting on 02 September 2020. The CoTCCC conducted voting on the guideline changes in early October 2020 with subsequent inclusion in the updated TCCC Guidelines published on 01 November 2020.1.

Elucidating the origins of enhanced CO2 reduction in manganese electrocatalysts bearing pendant hydrogen-bond donors.

Complexes of the general form [Mn(X)(CO)3bpy] (X = a variety of monodentate ligands, bpy = 2,2'-bipyridine) have been reported to act as electrocatalysts for the reduction of CO2 to CO. In this work, a series of phenol and anisole substituted bipyridine ligands were synthesized and ligated to a manganese metal center in order to probe for an intramolecular hydrogen-bonding interaction in the transition state of CO2 reduction. Ligands without the ability to intramolecularly hydrogen bond displayed decreased catalytic current density compared to those with the ability to hydrogen bond with CO2. Electrocatalysis was studied by performing voltammetric and bulk electrolysis experiments under argon or CO2 environments. Measurements of catalytic rates using hydrogen vs. deuterium for the intramolecular H/D-bonding step show that there is an isotope effect associated with the catalysis. The data presented herein suggest a mechanism involving two subsequent equilibrium isotope effects in combination with a primary kinetic isotope effect.

TCCC Guidelines Comprehensive Review and Update: TCCC Guidelines Change 16-03.

Based on careful review of the Tactical Combat Casualty Care (TCCC) Guidelines, the authors developed a list of proposed changes for inclusion in a comprehensive change proposal. To be included in the proposal, individual changes had to meet at least one of three criteria: (1) The change was primarily tactical rather than clinical; (2) the change was a minor modification to the language of an existing TCCC Guideline; and (3) the change, though clinical, was straightforward and noncontentious. The authors presented their list to the TCCC Working Group for review and approval at the 7 September 2016 meeting of the Committee on Tactical Combat Casualty Care (CoTCCC). Twenty-three items met with general agreement and were retained in this change proposal.

Design of a Catalytic Active Site for Electrochemical CO2 Reduction with Mn(I)-Tricarbonyl Species.

The design, synthesis, and assessment of a new manganese-centered catalyst for the electrochemical reduction of CO2 is described. The reported species, MnBr(6-(2-hydroxyphenol)-2,2'-bipyridine)(CO)3, includes a ligand framework with a phenolic proton in close proximity to the CO2 binding site, which allows for facile proton-assisted C-O bond cleavage. As a result of this modification, seven times the electrocatalytic current enhancement is observed compared to MnBr(2,2'-bipyridine)(CO)3. Moreover, reduction is possible at only 440 mV of overpotential. Theoretical computations suggest that the entropic contribution to the activation free energy is partially responsible for the increased catalytic activity. Experimental work, including voltammetry and product quantification from controlled potential electrolysis, suggests a key mechanistic role for the phenolic proton in the conversion of CO2 to CO.

Exploring the effect of axial ligand substitution (X = Br, NCS, CN) on the photodecomposition and electrochemical activity of [MnX(N-C)(CO)3] complexes.

The synthesis, electrochemical activity, and relative photodecomposition rate is reported for four new Mn(i) N-heterocyclic carbene complexes: [MnX(N-ethyl-N'-2-pyridylimidazol-2-ylidine)(CO)3] (X = Br, NCS, CN) and [MnCN(N-ethyl-N'-2-pyridylbenzimidazol-2-ylidine)(CO)3]. All compounds display an electrocatalytic current enhancement under CO2 at the potential of the first reduction, which ranges from -1.53 V to -1.96 V versus the saturated calomel electrode. Catalytic CO production is observed for all species during four-hour preparative-scale electrolysis, but substantial H2 is detected in compounds where X is not Br. All species eventually decompose under both 350 nm and 420 nm light, but cyanide substituted complexes (X = CN) last significantly longer (up to 5×) under 420 nm light as a result of a blue-shifted MLCT band.

NHC-containing manganese(I) electrocatalysts for the two-electron reduction of CO2.

The synthesis and characterization of the first catalytic manganese N-heterocyclic carbene complexes are reported: MnBr(N-methyl-N'-2-pyridylbenzimidazol-2-ylidine)(CO)3 and MnBr(N-methyl-N'-2-pyridylimidazol-2-ylidine)(CO)3. Both new species mediate the reduction of CO2 to CO following two-electron reduction of the Mn(I) center, as observed with preparative scale electrolysis and verified with (13)CO2. The two-electron reduction of these species occurs at a single potential, rather than in two sequential steps separated by hundreds of millivolts, as is the case for previously reported MnBr(2,2'-bipyridine)(CO)3. Catalytic current enhancement is observed at voltages similar to MnBr(2,2'-bipyridine)(CO)3.

Neuronal growth promoting sesquiterpene-neolignans; syntheses and biological studies.

The use of small molecules that can promote neuronal growth represents a promising approach to regenerative science. Along these lines we have developed separate short or modular syntheses of the natural products caryolanemagnolol and clovanemagnolol, small molecules previously shown to promote neuronal growth and induce choline acetyltransferase activity. The postulated biosynthetic pathways, potentially leading to the assembly of these molecules in nature, have guided the laboratory syntheses, allowing the preparation of both natural products in as few as two steps. With synthetic access to the compounds as single enantiomers we have examined clovanemagnolol's ability to promote the growth of embryonic hippocampal and cortical neurons. Clovanemagnolol has been shown to be a potent neurotrophic agent, promoting neuronal growth at concentrations of 10 nM.

Hydroxyl-directed cyclizations of 1,6-enynes.

The palladium-catalyzed, hydroxyl-directed cyclization reactions of 1,6-enynes provide a highly diastereoselective process for the syntheses of stereochemically defined cyclopentanes. Consistently high levels of cis-selectivity are possible using homopropargyl alcohols in contrast to the corresponding propargyl alcohols. Hydroborylative enyne cyclizations coupled with this directing group effect provide a useful method for the syntheses of multifaceted compounds bearing all carbon quaternary centers.

Biomimetic syntheses of the neurotrophic natural products caryolanemagnolol and clovanemagnolol.

Separate short and modular syntheses of the isomeric natural products caryolanemagnolol and clovanemagnolol have been achieved starting from commercially available (-)-caryophyllene. The postulated biosynthetic pathways guided the syntheses of the neuroregenerative small molecules allowing their assembly in as few as two steps.

Elective parotidectomy in the management of advanced auricular malignancies.

OBJECTIVE: The purpose of this study is to determine whether elective parotidectomy is necessary in patients with clinically and radiographically N0 parotid disease with isolated primary auricular nonmelanoma cutaneous malignancies. Auricular malignancies are typically managed by wedge resection or wide local excision. Although small lesions are easily managed by conservative excision, large bulky tumors, those with multifocal involvement, and recalcitrant lesions, often require more extensive resection including total auriculectomy, parotidectomy, and/or neck dissection. STUDY DESIGN: A 10-year retrospective case review from four tertiary university medical centers from 1992 to 2002. METHODS: Information was retrospectively retrieved using a database of patients from the department of pathology. Seventy-one charts were reviewed. Patients with a clinical history of advanced nonmelanoma auricular carcinoma undergoing elective parotidectomy and/or neck dissection with clinically and radiographically N0 nodal disease were evaluated for the presence of occult parotid metastasis. All patients underwent parotidectomy in conjunction with a total auriculectomy for surgical extirpation of their primary auricular carcinoma. Parotid specimens were evaluated for histopathologic evidence of metastatic neoplastic disease. RESULTS: Pathological examination showed no histological evidence of occult parotid metastasis in all 19 patients who underwent elective parotidectomy in the presence of clinically and radiographically N0 nodal disease of the parotid or cervical regions. CONCLUSIONS: Parotidectomy may not be necessary in the surgical management of advanced auricularcarcinoma in the absence of clinically positive parotid disease or external auditory canal involvement.

Traumatic cholesteatoma presenting as a brain abscess: a case report.

OBJECTIVE: To discuss the clinical aspects and management of traumatic cholesteatomas of the temporal bone. STUDY DESIGN: Case report. SETTING: University hospital, tertiary referral center. PATIENT, INTERVENTION, AND RESULTS: The authors describe an uncommon case of otogenic brain abscess resulting from an infected cholesteatoma arising from an old temporal bone fracture line involving the external auditory canal in an otherwise healthy 21-year-old man. The patient was successfully treated with brain abscess drainage, tympanomastoidectomy, and broad-spectrum intravenous antibiotic therapy. CONCLUSIONS: The authors recommend long-term follow-up in any patient with a longitudinal or mixed temporal bone fracture with low threshold for obtaining temporal bone computer tomography imaging for any new otologic complaints. Traumatic cholesteatomas complicated by brain abscess should be treated with broad-spectrum intravenous antibiotic therapy and aggressive surgical intervention.