Hypothermia and the Global War on Terror: 18 Years of Minimal Progress.

INTRODUCTION: The association between hypothermia, coagulopathy, and acidosis in trauma is well described. Hypothermia mitigation starts in the prehospital setting; however, it is often a secondary focus after other life-saving interventions. The deployed environment further compounds the problem due to prolonged evacuation times in rotary wing aircraft, resource limitations, and competing priorities. This analysis evaluates hypothermia in combat casualties and the relationship to resuscitation strategy with blood products. METHODS: Using the data from the Department of Defense Joint Trauma Registry from 2003 to 2021, a retrospective analysis was conducted on adult trauma patients. Inclusion criteria was arrival at the first military treatment facility (MTF) hypothermic (<95ºF). Study variables included: mortality, year, demographics, battle vs non-battle injury, mechanism, theater of operation, vitals, and labs. Subgroup analysis was performed on severely injured (15 < ISS < 75) hypothermic trauma patients resuscitated with whole blood (WB) vs only component therapy. RESULTS: Of the 69,364 patients included, 908 (1.3%) arrived hypothermic; the vast majority of whom (N = 847, 93.3%) arrived mildly hypothermic (90-94.9°F). Overall mortality rate was 14.8%. Rates of hypothermia varied by year from 0.7% in 2003 to 3.9% in 2014 (P <0.005). On subgroup analysis, mortality rates were similar between patients resuscitated with WB vs only component therapy; though base deficit values were higher in the WB cohort (-10 vs -6, P < 0.001). CONCLUSION: Despite nearly 20 years of combat operations, hypothermia continues to be a challenge in military trauma and is associated with a high mortality rate. Mortality was similar between hypothermic trauma patients resuscitated with WB vs component therapy, despite greater physiologic derangements on arrival in patients who received WB. As the military has the potential to conduct missions in environments where the risk of hypothermia is high, further research into hypothermia mitigation techniques and resuscitation strategies in the deployed setting is warranted.

Who Says You can't go FAST at Night? Use of a Novel Ultrasound-Capable Night Vision Device for Prehospital Medical Personnel to Identify Noncompressible Truncal Hemorrhage.

BACKGROUND: Early detection of abdominal hemorrhage via ultrasound has life-saving implications for military and civilian trauma. However, strict adherence to light discipline may prohibit the use of ultrasound devices in the deployed setting. Additionally, current night vision devices remain noncompatible with ultrasound technology. This study sought to assess an innovative night vision device with ultrasound capable picture-in-picture display via a intraabdominal hemorrhage model to identify noncompressible truncal hemorrhage in blackout conditions. METHODS: 8 post mortem fetal porcine specimens were used and divided into 2 groups: intrabdominal hemorrhage (n = 4) vs no hemorrhage (n = 4). Intrabdominal hemorrhage was modeled via direct injection of 200 mL of normal saline into the peritoneal cavity. Under blackout conditions, 5 participants performed a focused assessment with sonography for trauma (FAST) exam on each model using the prototype ultrasound-capable night vision device. RESULTS: Of the 40 FAST exams performed, 95% (N = 38) resulted in the correct identification of intraabdominal hemorrhage. Of the incorrectly identified exams, both were false positives resulting in a 100% sensitivity, 90% specificity, 91% positive predictive value, and a 100% negative predictive value. All participants noted the novel device was easy to use and provided superior visualization for performing FAST exams under blackout conditions. CONCLUSION: The ultrasound-enabled night vision prototype demonstrated promising results in identifying noncompressible truncal hemorrhage while maintaining strict light discipline in blackout conditions. Further research efforts should be directed at assessing the ability of providers to perform procedures in blackout conditions using the ultrasound-enabled prototype night vision device.

Phylogenetic network classes through the lens of expanding covers.

It was recently shown that a large class of phylogenetic networks, the 'labellable' networks, is in bijection with the set of 'expanding' covers of finite sets. In this paper, we show how several prominent classes of phylogenetic networks can be characterised purely in terms of properties of their associated covers. These classes include the tree-based, tree-child, orchard, tree-sibling, and normal networks. In the opposite direction, we give an example of how a restriction on the set of expanding covers can define a new class of networks, which we call 'spinal' phylogenetic networks.

Catatonia and melancholia interface: exploring a new paradigm for evaluation and treatment. A case series and literature review.

Background: Catatonia has been increasingly associated with mood disorders and is recognized as a specifier in the DSM-5 and DSM-5-TR. The DSM-5-TR recognizes melancholia as a specifier for depressive episodes in major depressive disorder and bipolar disorder. It is characterized by severe anhedonia, lack of reactivity, excessive or delusional guilt, and significant vegetative symptoms. As the conceptualization of melancholia expanded beyond its mood components to include psychomotor disturbances, its overlap with psychomotor symptoms or catatonia becomes evident. This overlap was also described in Kahlbaum's original literature, where he describes the transition between states of melancholia, mania, and catatonia. Method: Case summary of six patients with major depressive disorder or depressed phase of bipolar disorder who were admitted for severe depression, anhedonia, intense anxiety, psychomotor agitation or retardation, indecisiveness, perseveration, and vegetative symptoms such as poor sleep, appetite, and significant weight loss. Results: All patients demonstrated rapid and complete resolution of their mood and psychomotor symptoms, indecisiveness, perseveration, as well as psychosis shortly after administration of lorazepam, with recurrence of the above symptoms upon lorazepam discontinuation and resolution upon resumption, in an on-and-off manner. Conclusion: The present study argues for a closer relationship between melancholia and catatonia based on our case series, historical review, overlap in phenomenology, and response to treatment. We propose provisional [Mahgoub] criteria for patients with severe depression and melancholia. The role of GABA agonists, such as lorazepam, can be explored as an option for patients with treatment-resistant depression who meet these criteria for melancholia. Limitations: Absence of a standardized, systematic assessment tool and a small sample size.

Mortality in hypotensive combat casualties who require emergent laparotomy in the forward deployed environment.

INTRODUCTION: Mortality rates among hypotensive civilian patients requiring emergent laparotomy exceed 40%. Damage control (DCR) principles were incorporated into the military's Clinical Practice Guidelines (CPG) in 2008. We examined combat casualties requiring emergent laparotomy to characterize how mortality rates compare to hypotensive civilian trauma patients. METHODS: The DoD Trauma Registry (2004-2020) was queried for adults who underwent combat laparotomy. Patients who were hypotensive were compared to normotensive patients. Mortality was the outcome of interest. Mortality rates before (2004-2007) and after (2009-2020) DCR CPG implementation were analyzed. RESULTS: 1051 patients were studied. Overall mortality was 6.5% for normotensive casualties and 28.7% for hypotensive casualties. Mortality decreased in normotensive patients but remained unchanged in hypotensive patients following the implementation of the DCR CPG. CONCLUSION: Hypotensive combat casualties undergoing emergent laparotomy demonstrated a mortality rate of 29.5%. Despite many advances, mortality rates remain high in hypotensive patients requiring emergent laparotomy.

The use of mobile thermal imaging and machine learning technology for the detection of early surgical site infections.

BACKGROUND: Surgical Site Infections (SSI) yield subtle, early signs that are not readily identifiable. This study sought to develop a machine learning algorithm that could identify early SSIs based on thermal images. METHODS: Images were taken of surgical incisions on 193 patients who underwent a variety of surgical procedures. Two neural network models were generated to detect SSIs, one using RGB images, and one incorporating thermal images. Accuracy and Jaccard Index were the primary metrics by which models were evaluated. RESULTS: Only 5 patients in our cohort developed SSIs (2.8%). Models were instead generated to demarcate the wound site. The models had 89-92% accuracy in predicting pixel class. The Jaccard indices for the RGB and RGB â€‹+ â€‹Thermal models were 66% and 64%, respectively. CONCLUSIONS: Although the low infection rate precluded the ability of our models to identify surgical site infections, we were able to generate two models to successfully segment wounds. This proof-of-concept study demonstrates that computer vision has the potential to support future surgical applications.

An algebraic model for inversion and deletion in bacterial genome rearrangement.

Inversions, also sometimes called reversals, are a major contributor to variation among bacterial genomes, with studies suggesting that those involving small numbers of regions are more likely than larger inversions. Deletions may arise in bacterial genomes through the same biological mechanism as inversions, and hence a model that incorporates both is desirable. However, while inversion distances between genomes have been well studied, there has yet to be a model which accounts for the combination of both deletions and inversions. To account for both of these operations, we introduce an algebraic model that utilises partial permutations. This leads to an algorithm for calculating the minimum distance to the most recent common ancestor of two bacterial genomes evolving by inversions (of adjacent regions) and deletions. The algebraic model makes the existing short inversion models more complete and realistic by including deletions, and also introduces new algebraic tools into evolutionary distance problems.

Rapid cold sterilization of 3D printed surgical instruments for the austere environment.

INTRODUCTION: Medical operations are vulnerable to global supply chain fluctuations. The ability to locally produce and reliably sterilize medical equipment may mitigate this risk. This project developed a reliable high-level disinfection process for 3D printed surgical tools. METHODS: Surgical instruments and consumables were designed and printed from various materials. Devices contaminated with known and unknown bacteria underwent one of three cleaning methods followed by high-level disinfection using submersion in a Cidex OPA Solution. Devices were then cultured on blood agar plates and incubated for 48 h. Positive and negative controls were performed. RESULTS: The results of control experiments showed no growth on negative controls and significant growth on all positive control plates. Of the three cleaning methods tested, one showed no growth: cleaning with isopropyl alcohol and chlorhexidine followed by Cidex bath. DISCUSSION: This project successfully developed a rapid high-level disinfection process for 3D printed surgical instruments made from two different types of 3D printing material.

Evidence-based consensus guidelines for the management of catatonia: Recommendations from the British Association for Psychopharmacology.

The British Association for Psychopharmacology developed an evidence-based consensus guideline on the management of catatonia. A group of international experts from a wide range of disciplines was assembled. Evidence was gathered from existing systematic reviews and the primary literature. Recommendations were made on the basis of this evidence and were graded in terms of their strength. The guideline initially covers the diagnosis, aetiology, clinical features and descriptive epidemiology of catatonia. Clinical assessments, including history, physical examination and investigations are then considered. Treatment with benzodiazepines, electroconvulsive therapy and other pharmacological and neuromodulatory therapies is covered. Special regard is given to periodic catatonia, malignant catatonia, neuroleptic malignant syndrome and antipsychotic-induced catatonia. There is attention to the needs of particular groups, namely children and adolescents, older adults, women in the perinatal period, people with autism spectrum disorder and those with certain medical conditions. Clinical trials were uncommon, and the recommendations in this guideline are mainly informed by small observational studies, case series and case reports, which highlights the need for randomised controlled trials and prospective cohort studies in this area.

Labellable Phylogenetic Networks.

Phylogenetic networks are mathematical representations of evolutionary history that are able to capture both tree-like evolutionary processes (speciations) and non-tree-like 'reticulate' processes such as hybridization or horizontal gene transfer. The additional complexity that comes with this capacity, however, makes networks harder to infer from data, and more complicated to work with as mathematical objects. In this paper, we define a new, large class of phylogenetic networks, that we call labellable, and show that they are in bijection with the set of 'expanding covers' of finite sets. This correspondence is a generalisation of the encoding of phylogenetic forests by partitions of finite sets. Labellable networks can be characterised by a simple combinatorial condition, and we describe the relationship between this large class and other commonly studied classes. Furthermore, we show that all phylogenetic networks have a quotient network that is labellable.

Pectin based biologic Velcro effectively seals traumatic solid organ and small bowel injuries.

INTRODUCTION: Injuries to the liver and small bowel are common in multiple injuries. While there are currently a variety of accepted damage-control techniques to expeditiously manage such injuries, morbidity and mortality remain high. Pectin polymers have previously been shown to effectively seal visceral organ injuries ex vivo through physiochemical entanglement with the glycocalyx. We sought to compare the standard of care for the management of penetrating liver and small bowel injuries with a pectin-based bioadhesive patch in a live animal model. METHODS: Fifteen adult male swine underwent a laparotomy with standardized laceration to the liver. Animals were randomized to one of three treatment arms: packing with laparotomy pads (n = 5), suture repair (n = 5), or pectin patch repair (n = 5). Following 2 hours of observation, fluid was evacuated from the abdominal cavity and weighed. Next, a full-thickness small bowel injury was created, and animals were randomized to either a sutured repair (n = 7) or pectin patch repair (n = 8). The segment of bowel was then pressurized with saline, and the burst pressure was recorded. RESULTS: All animals survived the protocol to completion. There were no clinically significant differences between groups regarding baseline vitals or laboratory studies. On one-way analysis of variance, there was a statistically significant difference between groups regarding blood loss after liver repair (26 mL suture vs. 33 mL pectin vs. 142 mL packing, p < 0.01). On post hoc analysis, there was no statistically significant difference between suture and pectin ( p = 0.9). After repair, small bowel burst pressures were similar between pectin and suture repair (234 vs. 224 mm Hg, p = 0.7). CONCLUSION: Pectin-based bioadhesive patches performed similarly to the standard of care for the management of liver lacerations and full-thickness bowel injuries. Further testing is warranted to assess the biodurability of a pectin patch repair, as it may offer a simple option to effectively temporize traumatic intra-abdominal injuries.

Bioadhesive patch as a parenchymal sparing treatment of acute traumatic pulmonary air leaks.

INTRODUCTION: Traumatic pulmonary injuries are common in chest trauma. Persistent air leaks occur in up to 46% of patients depending on injury severity. Prolonged leaks are associated with increased morbidity and cost. Prior work from our first-generation pectin patches successfully sealed pulmonary leaks in a cadaveric swine model. We now test the next-generation pectin patch against wedge resection in the management of air leaks in anesthetized swine. METHODS: A continuous air leak of 10% to 20% percent was created to the anterior surface of the lung in intubated and sedated swine. Animals were treated with a two-ply pectin patch or stapled wedge resection (SW). Tidal volumes (TVs) were recorded preinjury and postinjury. Following repair, TVs were recorded, a chest tube was placed, and animals were observed for presence air leak at closure and for an additional 90 minutes while on positive pressure ventilation. Mann-Whitney U test and Fisher's exact test used to compare continuous and categorical data between groups. RESULTS: Thirty-one animals underwent either SW (15) or pectin patch repair (PPR, 16). Baseline characteristics were similar between animals excepting baseline TV (SW, 10.3 mL/kg vs. PPR, 10.9 mL/kg; p = 0.03). There was no difference between groups for severity of injury based on percent of TV loss (SW, 15% vs. PPR, 14%; p = 0.5). There was no difference in TV between groups following repair (SW, 10.2 mL/kg vs. PPR, 10.2 mL/kg; p = 1) or at the end of observation (SW, 9.8 mL/kg vs. PPR, 10.2 mL/kg; p = 0.4). One-chamber intermittent air leaks were observed in three of the PPR animals, versus one in the SW group ( p = 0.6). CONCLUSION: Pectin patches effectively sealed the lung following injury and were noninferior when compared with wedge resection for the management of acute traumatic air leaks. Pectin patches may offer a parenchymal sparing option for managing such injuries, although studies evaluating biodurability are needed.

Impact of COVID on surgical case volume at military treatment facilities with surgical residencies.

INTRODUCTION: The Military Health System (MHS) is tasked with the dual mission of providing medical care to beneficiaries while ensuring medical readiness. MHS provides care through a combination of military treatment facilities (MTF) ("direct care"; DC) & off-base civilian facilities ("purchased care"; PC). Given recent concerns regarding low surgical volume at MTFs, we sought to evaluate COVID's impact on elective and non-elective case volume at MTFs with surgical residencies. METHODS: Retrospective review of 2017-2021 M2 database was performed on Tricare beneficiaries who underwent bariatric surgery or major colorectal surgery in the DC or PC market at, or, surrounding MTFs with surgical residencies. Procedures were identified using ICD-10 procedure codes and Medicare severity-diagnosis related groups. A detailed analysis was then performed on changes in case volume in the DC and PC markets. RESULTS: 5,698 bariatric and 5,517 major colorectal procedures were performed during the study period. There was an 84% vs 20% quarterly decrease in elective bariatric surgeries completed in the DC and PC markets from Q1 to Q2 2020. Pre to post-COVID (Q1 2017 - Q1 2020 vs Q3 2020 - Q4 2021) there was a decrease in the percentage of bariatric surgeries completed in the DC market (74.1% vs 55.0%, p = 0.001). Meanwhile, major colorectal surgery quarterly case volume remained unchanged in the DC (137 vs 125, p = 0.18) and PC (146 v 137, p = 0.13) markets, pre- and post-COVID. DISCUSSION: Bariatric surgical case volume at MTFs disproportionately decreased during COVID when compared to the PC market and major colorectal cases. Bariatric case volume has rebounded in PC markets surpassing pre-COVID levels while DC case volume remains depressed. Further attention is warranted regarding decreased elective surgical case volume at MTFs.

Phylogenetic Diversity Rankings in the Face of Extinctions: The Robustness of the Fair Proportion Index.

Planning for the protection of species often involves difficult choices about which species to prioritize, given constrained resources. One way of prioritizing species is to consider their "evolutionary distinctiveness," (ED) that is, their relative evolutionary isolation on a phylogenetic tree. Several evolutionary isolation metrics or phylogenetic diversity indices have been introduced in the literature, among them the so-called Fair Proportion (FP) index (also known as the ED score). This index apportions the total diversity of a tree among all leaves, thereby providing a simple prioritization criterion for conservation. Here, we focus on the prioritization order obtained from the FP index and analyze the effects of species extinction on this ranking. More precisely, we analyze the extent to which the ranking order may change when some species go extinct and the FP index is recomputed for the remaining taxa. We show that for each phylogenetic tree, there are edge lengths such that the extinction of one leaf per cherry completely reverses the ranking. Moreover, we show that even if only the lowest-ranked species goes extinct, the ranking order may drastically change. We end by analyzing the effects of these two extinction scenarios (extinction of the lowest-ranked species and extinction of one leaf per cherry) for a collection of empirical and simulated trees. In both cases, we can observe significant changes in the prioritization orders, highlighting the empirical relevance of our theoretical findings. [Biodiversity conservation; Fair Proportion index; phylogenetic diversity; species prioritization.].

Immediate Deep Inferior Epigastric Perforator Flap Reconstruction of a Giant Phyllodes Tumor.

We present a case of a giant phyllodes tumor (PT) requiring simple mastectomy with en bloc pectoralis major resection and immediate deep inferior epigastric perforator (DIEP) flap reconstruction. This patient presented with a four-year history of an enlarging breast mass with ultrasound-guided biopsy results consistent with atypical fibroepithelial proliferation that was highly concerning for a borderline phyllodes tumor. In this large, rare breast tumor that required en bloc pectoralis major resection, we describe the novel use of an immediate single pedicled DIEP flap for the resulting chest wall defect. The patient's postoperative course was uncomplicated, and she reported satisfactory cosmetic and functional outcomes at her initial postoperative follow-up visits. Our findings support the use of simple mastectomy with en bloc resection and immediate single-pedicled DIEP flap for the definitive treatment of giant phyllodes tumors. Our experience shows this is a safe and effective technique for achieving adequate oncologic resection while maintaining postoperative function and cosmesis, which are essential for patient quality of life.

Electroconvulsive Therapy-Resistant Catatonia: Case Report and Literature Review.

BACKGROUND: Untreated catatonia is associated with serious medical complications that can necessitate urgent medical attention. Lorazepam and electroconvulsive therapy (ECT) are effective for catatonia across various psychiatric or medical diagnoses. In rare cases, ECT fails to achieve full response in catatonic symptoms, particularly in patients with chronic catatonia or primary psychotic disorder. Evidence on treating catatonia that does not respond to ECT is lacking. OBJECTIVE: Conduct a literature review on treatment of ECT-resistant catatonia which is defined as that reported lack of full response to ECT treatments. We present a case of a 52-year-old male with schizophrenia where catatonia did not respond to lorazepam and robust ECT but resolved after memantine titration. METHODS: A literature review was performed using Medline/PubMed with the following keywords: treatment-resistant, catatonia, electroconvulsive therapy. References in eligible articles and most recent systematic reviews on catatonia treatment were reviewed. RESULTS: Seventeen patients in 12 case reports were identified where the treatment of catatonia was described after failed ECT trials. Most had chronic catatonia and a diagnosis of schizophrenia. ECT parameters and ictal outcome measures were not consistently reported. Treatment modalities for ECT-resistant catatonia included amantadine, memantine, lorazepam augmentation to ECT, and antiepileptic and antipsychotic medications such as aripiprazole and clozapine. CONCLUSIONS: The literature review and new case suggest reconsideration of catatonia diagnosis, optimizing ECT treatments, cautious use of antipsychotics, consideration of lorazepam augmentation to ECT treatments, and/or use of N-methyl-D-aspartate receptor antagonists.