Reporting of coronary artery calcification on chest CT studies in patients with interstitial lung disease.

AIM: To evaluate the prevalence of coronary artery calcification (CAC) on non-contrast computed tomography (CT) of the thorax in patients with interstitial lung disease (ILD), assess consistency of CAC reporting and assess incidence of subsequent cardiac events. MATERIALS AND METHODS: Patients with known interstitial lung disease who underwent a CT thorax over a 2-year period were retrospectively reviewed. Presence of CAC was assessed using a visual scale for CAC reporting and graded as mild, moderate, or severe by two cardiothoracic radiologists. CT reports were reviewed to determine if presence of CAC had been described. Electronic medical records were reviewed for any subsequent cardiothoracic events from the date of the CT thorax to present. RESULTS: 254 patients were included in the analysis (54.7% men; mean age 59.9 yo). 43.7% had CAC on their CT thorax; however, in 87.3% of those, reports did not comment on its presence. 8 patients had cardiac events; 7 of them had CAC on CT although only in 1 case this was reported. Global CAC and LAD CAC Patients with cardiac events had a significantly higher global CAC (p=0.016) and LAD CAC (p=0.048) when compared to patients without. CONCLUSION: We demonstrated a high prevalence of CAC in ILD patients and its significant association with adverse cardiac events. Unfortunately, CAC on CT thorax is still largely unreported. As per recent BSCI/BSCCT and BSTI guidelines, reporting of CAC should become part of routine practice, as may prompt prevention and impact on patients outcome.

Eliminating the benzos: A benzodiazepine-sparing approach to preventing and treating alcohol withdrawal syndrome.

BACKGROUND: Alcohol withdrawal syndrome (AWS) represents significant cost to the hospitalized trauma population from a clinical and financial perspective. Historically, AWS has been managed with benzodiazepines. Despite their efficacy, benzodiazepines carry a heavy adverse effect profile. Recently, benzodiazepine-sparing protocols for the prophylaxis and treatment of AWS have been used in medical patient populations. Most existing benzodiazepine-sparing protocols use phenobarbital, while ours primarily uses gabapentin and clonidine, and no such protocol has been developed and examined for safety and efficacy specifically within a trauma population. METHODS: In December of 2019, we implemented our benzodiazepine-sparing protocol for trauma patients identified at risk for alcohol withdrawal on admission. Trauma patients at risk for AWS admitted to an academic Level 1 trauma center before (conventional) and after (benzodiazepine-sparing [BS]) protocol implementation were compared. Outcomes examined include morphine milligram equivalent dosing rates and lorazepam equivalent dosing rates as well as the Clinical Institute Withdrawal Assessment for Alcohol, revised (CIWA-Ar) scores, hospital length of stay, intensive care unit length of stay, and ventilator days. RESULTS: A total of 387 conventional and 134 benzodiazepine sparing patients were compared. Injury Severity Score (13 vs. 16, p = 0.10) and admission alcohol levels (99 vs. 149, p = 0.06) were similar. Patients in the BS pathway had a lower maximum daily CIWA-Ar (2.7 vs. 1.5, p = 0.04). While mean morphine milligram equivalent per day was not different between groups (31.5 vs. 33.6, p = 0.49), mean lorazepam equivalents per day was significantly lower in the BS group (1.1 vs. 0.2, p < 0.01). Length of stay and vent days were not different between the groups. CONCLUSION: Implementation of a benzodiazepine-sparing pathway that uses primarily clonidine and gabapentin to prevent and treat alcohol withdrawal syndrome in trauma patients is safe, reduces the daily maximum CIWA-Ar, and significantly decreases the need for benzodiazepines. Future studies will focus on outcomes affected by avoiding AWS and benzodiazepines in the trauma population. LEVEL OF EVIDENCE: Therapeutic/Care Management; Level IV.

Sigh Ventilation in Patients With Trauma: The SiVent Randomized Clinical Trial.

Importance: Among patients receiving mechanical ventilation, tidal volumes with each breath are often constant or similar. This may lead to ventilator-induced lung injury by altering or depleting surfactant. The role of sigh breaths in reducing ventilator-induced lung injury among trauma patients at risk of poor outcomes is unknown. Objective: To determine whether adding sigh breaths improves clinical outcomes. Design, Setting, and Participants: A pragmatic, randomized trial of sigh breaths plus usual care conducted from 2016 to 2022 with 28-day follow-up in 15 academic trauma centers in the US. Inclusion criteria were age older than 18 years, mechanical ventilation because of trauma for less than 24 hours, 1 or more of 5 risk factors for developing acute respiratory distress syndrome, expected duration of ventilation longer than 24 hours, and predicted survival longer than 48 hours. Interventions: Sigh volumes producing plateau pressures of 35 cm H2O (or 40 cm H2O for inpatients with body mass indexes >35) delivered once every 6 minutes. Usual care was defined as the patient's physician(s) treating the patient as they wished. Main Outcomes and Measures: The primary outcome was ventilator-free days. Prespecified secondary outcomes included all-cause 28-day mortality. Results: Of 5753 patients screened, 524 were enrolled (mean [SD] age, 43.9 [19.2] years; 394 [75.2%] were male). The median ventilator-free days was 18.4 (IQR, 7.0-25.2) in patients randomized to sighs and 16.1 (IQR, 1.1-24.4) in those receiving usual care alone (P = .08). The unadjusted mean difference in ventilator-free days between groups was 1.9 days (95% CI, 0.1 to 3.6) and the prespecified adjusted mean difference was 1.4 days (95% CI, -0.2 to 3.0). For the prespecified secondary outcome, patients randomized to sighs had 28-day mortality of 11.6% (30/259) vs 17.6% (46/261) in those receiving usual care (P = .05). No differences were observed in nonfatal adverse events comparing patients with sighs (80/259 [30.9%]) vs those without (80/261 [30.7%]). Conclusions and Relevance: In a pragmatic, randomized trial among trauma patients receiving mechanical ventilation with risk factors for developing acute respiratory distress syndrome, the addition of sigh breaths did not significantly increase ventilator-free days. Prespecified secondary outcome data suggest that sighs are well-tolerated and may improve clinical outcomes. Trial Registration: ClinicalTrials.gov Identifier: NCT02582957.

Aging to 24 months increased C57BL/6J mouse social sniffing and hippocampal Neto1 levels, and impaired female spatial learning.

Understanding how natural aging impacts rodent performance in translational behavior tests is critical to teasing apart impairments due to age-related decline from neurodegenerative disorder modeling. Reduced neuropilin and tolloid-like 1 (NETO1), an accessory protein of ionotropic glutamate receptors involved in synaptic plasticity, was associated with Alzheimer's disease, yet aging effects on Neto1 remain unclear. For these reasons, our goal was to characterize how Neto1 expression corresponded with social, repetitive, and spatial learning behaviors and stress response across the C57BL/6J mouse lifespan. We measured social preferences in three-chamber tests, and motor stereotypies by marble burying. Cognitive flexibility is typically assessed in the Morris water maze (MWM), wherein C57BL/6J mice exhibit deficits with age. However, fatigue or locomotor impairment may confound interpretation of MWM performance. Therefore, we used a less arduous water T-maze (WTM) to compare spatial learning flexibility in 2, 9-15, and 24-month-old male and female mice to test the hypothesis that deficits would emerge with age. In both sexes, 9-15-month-olds made more chamber entries during social preference tests, while 2-month-olds did less social sniffing than aged mice. No age or sex differences emerged in marble burying or serum corticosterone measurements. In 24-month-olds hippocampal Neto1was increased relative to 2-month-olds, and male cognitive flexibility was strong, while spatial learning and reversal learning of 24-month-old females was impaired in WTM irrespective of Neto1 expression. The WTM is a useful alternative assessment for cognitive flexibility deficits in aged mice, and the role of hippocampal Neto1 in promoting social sniffing is of interest.

Spinal motoneurons respond aberrantly to serotonin in a rabbit model of cerebral palsy.

Cerebral palsy (CP) is caused by a variety of factors that damage the developing central nervous system. Impaired motor control, including muscle stiffness and spasticity, is the hallmark of spastic CP. Rabbits that experience hypoxic-ischaemic (HI) injury in utero (at 70%-83% gestation) are born with muscle stiffness, hyperreflexia and, as recently discovered, increased 5-HT in the spinal cord. To determine whether serotonergic modulation of spinal motoneurons (MNs) contributes to motor deficits, we performed ex vivo whole cell patch clamp in neonatal rabbit spinal cord slices at postnatal day (P) 0-5. HI MNs responded to the application of α-methyl 5-HT (a 5-HT1 /5-HT2 receptor agonist) and citalopram (a selective 5-HT reuptake inhibitor) with increased amplitude and hyperpolarization of persistent inward currents and hyperpolarized threshold voltage for action potentials, whereas control MNs did not exhibit any of these responses. Although 5-HT similarly modulated MN properties of HI motor-unaffected and motor-affected kits, it affected sag/hyperpolarization-activated cation current (Ih ) and spike frequency adaptation only in HI motor-affected MNs. To further explore the differential sensitivity of MNs to 5-HT, we performed immunostaining for inhibitory 5-HT1A receptors in lumbar spinal MNs at P5. Fewer HI MNs expressed the 5-HT1A receptor compared to age-matched control MNs. This suggests that HI MNs may lack a normal mechanism of central fatigue, mediated by 5-HT1A receptors. Altered expression of other 5-HT receptors (including 5-HT2 ) likely also contributes to the robust increase in HI MN excitability. In summary, by directly exciting MNs, the increased concentration of spinal 5-HT in HI-affected rabbits can cause MN hyperexcitability, muscle stiffness and spasticity characteristic of CP. Therapeutic strategies that target serotonergic neuromodulation may be beneficial to individuals with CP. KEY POINTS: We used whole cell patch clamp electrophysiology to test the responsivity of spinal motoneurons (MNs) from neonatal control and hypoxia-ischaemia (HI) rabbits to 5-HT, which is elevated in the spinal cord after prenatal HI injury. HI rabbit MNs showed a more robust excitatory response to 5-HT than control rabbit MNs, including hyperpolarization of the persistent inward current and threshold voltage for action potentials. Although most MN properties of HI motor-unaffected and motor-affected kits responded similarly to 5-HT, 5-HT caused larger sag/hyperpolarization-activated cation current (Ih ) and altered repetitive firing patterns only in HI motor-affected MNs. Immunostaining revealed that fewer lumbar MNs expressed inhibitory 5-HT1A receptors in HI rabbits compared to controls, which could account for the more robust excitatory response of HI MNs to 5-HT. These results suggest that elevated 5-HT after prenatal HI injury could trigger a cascade of events that lead to muscle stiffness and altered motor unit development.

Reclaiming the management of common duct stones in acute care surgery.

BACKGROUND: Acute care surgery (ACS) is well positioned to manage choledocholithiasis at the time of laparoscopic cholecystectomy, but barriers to laparoscopic common bile duct exploration (LCBDE) include experience and the perceived need for specialized equipment. The technical complexity of this pathway is generally seen as challenging. As such, LCBDE is historically relegated to the "enthusiast." However, a simplified, effective LCBDE technique as part of a "surgery first" strategy could drive wider adoption in the specialty most often managing these patients. To determine efficacy and safety, we sought to compare our initial ACS-driven experience with a simple, fluoroscopy-guided, catheter-based LCBDE approach during laparoscopic cholecystectomy (LC) to LC with endoscopic retrograde cholangiopancreatography (ERCP). METHODS: We reviewed ACS patients who underwent LCBDE or LC + ERCP (pre-/postoperative) at a tertiary care center in the 4 years since starting this surgery first approach. Demographics, outcomes, and length of stay (LOS) were compared on an intention to treat basis. Laparoscopic common bile duct exploration was performed via using wire/catheter Seldinger techniques under fluoroscopic guidance with flushing or balloon dilation of the sphincter as needed. Our primary outcomes were LOS and successful duct clearance. RESULTS: One hundred eighty patients were treated for choledocholithiasis with 71 undergoing LCBDE. The success rate of catheter-based LCBDE was 70.4%. Length of stay was significantly reduced for the LCBDE group compared with the LC + ERCP group (48.8 vs. 84.3 hours, p < 0.01). Of note, there were no intraoperative or postoperative complications in the LCBDE group. CONCLUSION: A simplified catheter-based approach to LCBDE is safe and associated with decreased LOS when compared with LC + ERCP. This simplified step-up approach may help facilitate wider LCBDE utilization by ACS providers who are well positioned for a timely surgery first approach in the management of uncomplicated choledocholithiasis. LEVEL OF EVIDENCE: Therapeutic/Care Management; Level IV.

Blunt cerebrovascular injury: contribution of Timothy C Fabian MD and investigators from the University of Tennessee at Memphis to our understanding of the injury.

Our understanding of blunt cerebrovascular injury (BCVI) has evolved considerably over recent decades. It was once seen as a rare injury that was difficult or impossible to predict and had no useful prevention or treatment measures available. In the late 20th century, work by physicians caring for these injuries began to show that this was not the case. There were distinct risk factors for the injury and the often seen interval between injury and stroke provided an opportunity for stroke prevention. Timothy Fabian and the investigators at Memphis have been one of the groups at the forefront of this type of inquiry for >30 years. The contributions of this group has advanced the care of BCVI immensely. This review examines some of the work done by Dr Fabian and his colleagues and its importance in the care of injured patients.

Shear stimulated red blood cell microparticles: Effect on clot structure, flow and fibrinolysis.

BACKGROUND: Microparticles (MPs) have activity in thrombus promotion and generation. Erythrocyte microparticles (ErMPs) have been reported to accelerate fibrinolysis in the absence of permeation. We hypothesized that shear induced ErMPs would affect fibrin structure of clots and change flow with implications for fibrinolysis. OBJECTIVE: To determine the effect of ErMPs on clot structure and fibrinolysis. METHODS: Plasma with elevated ErMPs was isolated from whole blood or from washed red blood cells (RBCs) resuspended in platelet free plasma (PFP) after high shear. Dynamic light scattering (DLS) provided size distribution of ErMPs from sheared samples and unsheared PFP controls. Clots were formed by recalcification for flow/lysis experiments and examined by confocal microscopy and SEM. Flow rates through clots and time-to-lysis were recorded. A cellular automata model showed the effect of ErMPs on fibrin polymerization and clot structure. RESULTS: Coverage of fibrin increased by 41% in clots formed from plasma of sheared RBCs in PFP over controls. Flow rate decreased by 46.7% under a pressure gradient of 10 mmHg/cm with reduction in time to lysis from 5.7 ± 0.7 min to 12.2 ± 1.1 min (p < 0.01). Particle size of ErMPs from sheared samples (200 nm) was comparable to endogenous microparticles. CONCLUSIONS: ErMPs alter the fibrin network in a thrombus and affect hydraulic permeability resulting in decelerated delivery of fibrinolytic drugs.

Win or lose, nighttime transcystic laparoscopic common bile duct exploration is a win.

Objectives: Although controversial, recent data suggest nighttime versus daytime laparoscopic cholecystectomy (LC) have comparable outcomes. Laparoscopic common bile duct exploration (LCBDE) for choledocholithiasis decreases length of stay (LOS) as compared with LC with endoscopic retrograde cholangiopancreatography (ERCP) but increases case complexity/time. The influence of time of day on LCBDE outcomes has not been evaluated. Our aim was to examine outcomes and LOS for nighttime (PM) compared with daytime LC+LCBDE (DAY). Methods: Consecutive patients who underwent LCBDE were reviewed. Demographics, operative duration, success of LCBDE, time to postoperative ERCP (if required), LOS, and complications were compared. PM procedures were defined as beginning 19:00-07:00 hours. Results: Between 2018 and 2022, sixty patients underwent LCBDE (PM 42%). Groups had equivalent age/sex and preoperative liver function tests (LFTs). LCBDE success was 69% PM versus 71% DAY (p=0.78). Operative duration did not differ (2.8 IQR: 2.2-3.3 hours vs. 2.8 IQR: 2.3-3.2 hours, p=0.9). LOS was compared, and PM LOS was shorter (p=0.03). Time to ERCP after a failed LCBDE at night was compared with daytime (13.8 IQR: 10.6-29.5 hours vs. 19.9 IQR: 18.7-54.4 hours, p=0.07). LOS for failed PM LCBDE requiring ERCP was similar to successful DAY LCBDE (p=0.29). One complication (transient hyperbilirubinemia) was reported in the DAY group, none in PM. Conclusion: PM LCBDE cases are equivalent in safety and success rate to DAY cases but have reduced LOS. Widespread adoption of acute care surgery-driven management of choledocholithiasis via LCBDE during cholecystectomy may decrease LOS, especially in PM cases. Level of evidence: Level IV.

An interval of clinically silent gastrointestinal bleed in dysautonomic spinal cord injury: a case report.

BACKGROUND: Gastrointestinal bleed (GIB) has high incidence in traumatic spinal cord injured (tSCI) patients and can frequently be life-threatening, especially early post-injury. Several risk factors often compound bleeding risk, some are unique to this patient population. Normally, clinical suspicion for GIB arises from symptoms like coffee-ground emesis, hematemesis, melena or even hematochezia. A hemoglobin drop may be a late sign. Due to tSCI, however, patients often experience neurogenic bowels and dysautonomia, which may delay symptom presentation and complicate timely diagnosis of GIB. We report a case of an almost clinically silent GI bleed in the context of acute cervical tSCI. CASE PRESENTATION: A 21-year-old female presented with cervical cord transection at C-7 in the setting of motor vehicle rollover, for which surgical decompression was performed. During the acute injury phase, she also received a 10-day course of dexamethasone for symptomatic COVID-19 pneumonia. Two weeks after injury, she underwent percutaneous endoscopic gastrostomy (PEG) placement which demonstrated normal gastric and duodenal anatomy. One week later, a large spike (10x) in blood urea nitrogen: creatinine (BUN: Cr) ratio raised concern for GIB, but hemoglobin remained stable, and stool color remained unchanged. The following day, a gastroenterology consult was requested under increased suspicion of GIB from a sudden 3.5 g/dL hemoglobin drop. The patient received blood transfusion and pantoprazole. An upper endoscopy was performed, revealing three small duodenal ulcers. Melanotic stool ensued afterwards. CONCLUSIONS: Due to dysautonomia, clinical presentation of GIB can be significantly delayed in the tSCI patient population, leaving them vulnerable to succumb to illness. This case illustrates the possibility of an interval in which the patient was bleeding, with the sole indicator being an elevated BUN. Our case calls for closer monitoring of and vigilance for tSCI patients, and possibly employment of different strategies to reduce the incidence and enhance early detection of GIB in tSCI patients to subsequently decrease the morbidity and mortality associated with it.

Geographic Variation in Operative Management of Adhesive Small Bowel Obstruction.

INTRODUCTION: Variation in surgical management exists nationally. We hypothesize that geographic variation exists in adhesive small bowel obstruction (aSBO) management. MATERIALS AND METHODS: A retrospective analysis of a national commercial insurance claims database (MarketScan) sample (2017-2019) was performed in adults with hospital admission due to aSBO. Geographic variation in rates of surgical intervention for aSBO was evaluated by state and compared to a risk-adjusted national baseline using a Bayesian spatial rates Poisson regression model. For individual-level analysis, patients were identified in 2018, with 365-d look back and follow-up periods. Logistic regression was performed for individual-level predictors of operative intervention for aSBO. RESULTS: Two thousand one hundred forty-five patients were included. State-level analysis revealed rates of operative intervention for aSBO were significantly higher in Missouri and lower in Florida. On individual-level analysis, age (P < 0.01) and male sex (P < 0.03) but not comorbidity profile or prior aSBO, were negatively associated with undergoing operative management for aSBO. Patients presenting in 2018 with a history of admission for aSBO the year prior experienced a five-fold increase in odds of representation (odds ratio: 5.4, 95% confidence interval: 3.1-9.6) in 2019. Patients who received an operation for aSBO in 2018 reduced the odds of readmission in the next year by 77% (odds ratio: 0.23, 95% confidence interval: 0.1-0.5). The volume of operations performed within a state did not influence readmission. CONCLUSIONS: Surgical management of aSBO varies across the continental USA. Operative intervention is associated with decreased rates of representation in the following year. These data highlight a critical need for standardized guidelines for emergency general surgery patients.

Timing is everything: Early versus late palliative care consults in trauma.

BACKGROUND: The incorporation of dedicated palliative care (PC) services in the care of the critically injured trauma patient is not yet universal. Preexisting data demonstrate both economic and clinical value of PC consults, yet patient selection and optimal timing of these consults are poorly defined, possibly leading to underutilization of PC services. Prior studies in geriatric patients have shown benefits of PC when PC clinicians are engaged earlier during hospitalization. We aim to compare hospitalization metrics of early versus late PC consultation in trauma patients. METHODS: All patients 18 years or older admitted to the trauma service between January 1, 2019, and March 31, 2021, who received a PC consult were included. Patients were assigned to EARLY (PC consult ≤3 days after admission) and LATE (PC consult >3 days after admission) cohorts. Demographics, injury and underlying disease characteristics, outcomes, and financial data were compared. Length of stay (LOS) in the EARLY group is compared with LOS-3 in the LATE group. RESULTS: A total of 154 patient records met the inclusion criteria (60 EARLY and 94 LATE). Injury Severity Score, head Abbreviated Injury Scale score, and medical comorbidities (congestive heart failure, dementia, previous stroke, chronic obstructive pulmonary disease, malignancy) were similar between the groups. The LATE group was younger (69.9 vs. 75.3, p = 0.04). Patients in the LATE group had significantly longer LOS (17.5 vs. 7.0 days, p < 0.01) and higher median hospital costs ($53,165 vs. $17,654, p < 0.01). Patients in the EARLY group had reduced ventilator days (2.4 vs. 7.0, p < 0.01) and reduced rates of tracheostomies and surgical feeding tubes (1.7% vs. 11.7%, p = 0.03). CONCLUSION: Trauma patients with early PC consultation had shorter LOS, reduced ventilator days, reduced rates of invasive procedures, and lower costs even after correcting for delay to consult in the late group. These findings suggest the need for mechanisms leading to earlier PC consult in critically injured patients. LEVEL OF EVIDENCE: Therapeutic/Care Management; Level IV.

High-Level Coupled-Cluster Study on Substituent Effects in H2 Activation by Low-Valent Aluminyl Anions.

The synthesis of novel aluminyl anion complexes has been well exploited in recent years. Moreover, the elucidation of the structure and reactivity of these complexes opens the path toward a new understanding of low-valent aluminum complexes and their chemistry. This work computationally treats the substituent effect on aluminyl anions to discover suitable alternatives for H2 activation at a high level of theory utilizing coupled-cluster techniques extrapolated to the complete basis set. The results reveal that the simplest AlH2- system is the most reactive toward the activation of H2, but due to the low steric demand, severe difficulty in the stabilization of this system makes its use nonviable. However, the results indicate that, in principle, aluminyl systems with -C, -CN, -NC, and -N chelating centers would be the best choices of ligand toward the activation of molecular hydrogen by taking care of suitable steric demand to prevent dimerization of the catalysts. Furthermore, computations show that monosubstitution (besides -H) in aluminyl anions is preferred over disubstitution. So our predictions show that bidentate ligands may yield less reactive aluminyl anions to activate H2 than monodentate ones.

Above the Clavicle: A Simplified Screening Method for Asymptomatic Blunt Cerebral Vascular Injury.

INTRODUCTION: Blunt cerebrovascular injury (BCVI) is an increasingly detected pattern in trauma with significant morbidity, putting patients at risk for subsequent stoke. Complex screening protocols exist to determine who should undergo CT angiography of the neck (CTAN) to evaluate for BCVI. Once identified, stroke incidence may be reduced with appropriate treatment across grades. We hypothesize that an expanded and simplified method for identifying patients with clinical suspicion for BCVI based upon injury above the clavicle (ATC) will illustrate a previously undiagnosed cohort of patients. METHODS: A single-institution retrospective review of adult (age ≥18 years) blunt trauma patients with BCVI from January 1, 2010 to December 31, 2019 was conducted at a tertiary academic medical center. Patients undergoing CTAN were divided into 2 groups based upon qualification by either the expanded Denver criteria or clinical evidence of any injury ATC. RESULTS: A total of 219 patients were diagnosed with BCVI (25 566 blunt trauma admissions, .9% incidence). Seventeen patients (8%) who did not satisfy expanded Denver were diagnosed with BCVI by ATC, most commonly undergoing CTAN due to facial trauma (n = 8). There were no differences in distribution of carotid artery injuries (CAI) and vertebral artery injuries (VAI) in the expanded Denver criteria group compared to the ATC group. CONCLUSIONS: CTAN for blunt trauma with any injury ATC is an easy-to-use screening tool and may be seamlessly included with initial whole-body imaging.

Diagnostic Inaccuracies Using Extended Focused Assessment With Sonography in Trauma for Traumatic Pneumothorax.

BACKGROUND: Traumatic pneumothorax (PTX) can be deadly, and rapid diagnosis is vital. Ultrasound (US) is rapidly gaining acceptance as an accurate bedside diagnostic tool. While making the diagnosis is important, not all PTX require tube thoracostomy. Our goal was to evaluate the predictive ability of ultrasound in identifying clinically significant PTX. METHODS: Over 13 months, data was collected on patients undergoing evaluation for trauma. Patients were included if they underwent US, radiograph chest X-ray (CXR), and computed tomography of the chest. Predictive ability of ultrasound was evaluated in identifying clinically significant PTX. RESULTS: Ninety-four patients received evaluation by all 3 modalities. Of these, 32% were diagnosed with PTX. Sixteen patients (17%) had a clinically significant PTX. Chest X-ray and US both had a sensitivity of 75%; however, US had more than twice as many false positives, resulting in a much lower positive predictive value (63% vs 80%). CONCLUSIONS: While US can reliably rule out PTX, it may be overly sensitive diagnosing clinically significant PTX. Ultrasound alone should not be used in determining the need for tube thoracostomy as many patients will not require acute intervention.

Inhibitory interneurons show early dysfunction in a SOD1 mouse model of amyotrophic lateral sclerosis.

Few studies in amyotrophic lateral sclerosis (ALS) measure effects of the disease on inhibitory interneurons synapsing onto motoneurons (MNs). However, inhibitory interneurons could contribute to dysfunction, particularly if altered before MN neuropathology, and establish a long-term imbalance of inhibition/excitation. We directly assessed excitability and morphology of glycinergic (GlyT2 expressing) ventral lumbar interneurons from SOD1G93AGlyT2eGFP (SOD1) and wild-type GlyT2eGFP (WT) mice on postnatal days 6-10. Patch clamp revealed dampened excitability in SOD1 interneurons, including depolarized persistent inward currents (PICs), increased voltage and current threshold for firing action potentials, along with a marginal decrease in afterhyperpolarization duration. Primary neurites of ventral SOD1 inhibitory interneurons were larger in volume and surface area than WT. GlyT2 interneurons were then divided into three subgroups based on location: (1) interneurons within 100 µm of the ventral white matter, where Renshaw cells (RCs) are located, (2) interneurons interspersed with MNs in lamina IX, and (3) interneurons in the intermediate ventral area including laminae VII and VIII. Ventral interneurons in the RC area were the most profoundly affected, exhibiting more depolarized PICs and larger primary neurites. Interneurons in lamina IX had depolarized PIC onset. In lamina VII-VIII, interneurons were least affected. In summary, inhibitory interneurons show very early region-specific perturbations poised to impact excitatory/inhibitory balance of MNs, modify motor output and provide early biomarkers of ALS. Therapeutics like riluzole that universally reduce CNS excitability could exacerbate the inhibitory dysfunction described here. KEY POINTS: Spinal inhibitory interneurons could contribute to amyotrophic lateral sclerosis (ALS) pathology, but their excitability has never been directly measured. We studied the excitability and morphology of glycinergic interneurons in early postnatal transgenic mice (SOD1G93A GlyT2eGFP). Interneurons were less excitable and had marginally smaller somas but larger primary neurites in SOD1 mice. GlyT2 interneurons were analysed according to their localization within the ventral spinal cord. Interestingly, the greatest differences were observed in the most ventrally located interneurons. We conclude that inhibitory interneurons show presymptomatic changes that may contribute to excitatory/inhibitory imbalance in ALS.