Imaging approach to COVID-19 associated pulmonary embolism.

The novel coronavirus disease-2019 (COVID-19) illness and deaths, caused by the severe acute respiratory syndrome coronavirus-2, continue to increase. Multiple reports highlight the thromboembolic complications, such as pulmonary embolism (PE), in COVID-19. Imaging plays an essential role in the diagnosis and management of COVID-19 patients with PE. There continues to be a rapid evolution of knowledge related to COVID-19 associated PE. This review summarises the current understanding of prevalence, pathophysiology, role of diagnostic imaging modalities, and management, including catheter-directed therapy for COVID-19 associated PE. It also describes infection control considerations for the radiology department while providing care for patients with COVID-19 associated PE.

Performance of a Severity Score on Admission Chest Radiography in Predicting Clinical Outcomes in Hospitalized Patients With Coronavirus Disease (COVID-19).

BACKGROUND. Chest radiographs (CXRs) are typically obtained early in patients admitted with coronavirus disease (COVID-19) and may help guide prognosis and initial management decisions. OBJECTIVE. The purpose of this study was to assess the performance of an admission CXR severity scoring system in predicting hospital outcomes in patients admitted with COVID-19. METHODS. This retrospective study included 240 patients (142 men, 98 women; median age, 65 [range, 50-80] years) admitted to the hospital from March 16 to April 13, 2020, with COVID-19 confirmed by real-time reverse-transcriptase polymerase chain reaction who underwent chest radiography within 24 hours of admission. Three attending chest radiologists and three radiology residents independently scored patients' admission CXRs using a 0- to 24-point composite scale (sum of scores that range from 0 to 3 for extent and severity of disease in upper and lower zones of left and right lungs). Interrater reliability of the score was assessed using the Kendall W coefficient. The mean score was obtained from the six readers' scores for further analyses. Demographic variables, clinical characteristics, and admission laboratory values were collected from electronic medical records. ROC analysis was performed to assess the association between CXR severity and mortality. Additional univariable and multivariable logistic regression models incorporating patient characteristics and laboratory values were tested for associations between CXR severity and clinical outcomes. RESULTS. Interrater reliability of CXR scores ranged from 0.687 to 0.737 for attending radiologists, from 0.653 to 0.762 for residents, and from 0.575 to 0.666 for all readers. A composite CXR score of 10 or higher on admission achieved 53.0% (35/66) sensitivity and 75.3% (131/174) specificity for predicting hospital mortality. Hospital mortality occurred in 44.9% (35/78) of patients with a high-risk admission CXR score (≥ 10) versus 19.1% (31/162) of patients with a low-risk CXR score (< 10) (p < .001). Admission composite CXR score was an independent predictor of death (odds ratio [OR], 1.17; 95% CI, 1.10-1.24; p < .001). composite CXR score was a univariable predictor of intubation (OR, 1.23; 95% CI, 1.12-1.34; p < .001) and continuous renal replacement therapy (CRRT) (OR, 1.15; 95% CI, 1.04-1.27; p = .007) but was not associated with these in multivariable models (p > .05). CONCLUSION. For patients admitted with COVID-19, an admission CXR severity score may help predict hospital mortality, intubation, and CRRT. CLINICAL IMPACT. CXR may assist risk assessment and clinical decision-making early in the course of COVID-19.

The Impact of Spinal Cord Stimulation on Sleep Patterns.

BACKGROUND: Studies of chronic pain show sleep disturbances to be a prevalent symptom in 50-88% of patients and studies show improved pain to correspond with improved sleep. The impact of spinal cord stimulation (SCS) on sleep in failed back surgery syndrome, complex regional pain syndrome, and neuropathic pain patients has not been studied prospectively. OBJECTIVES: We prospectively assess the impact of SCS on sleep quality using the Insomnia Severity Index (ISI) and Epworth Sleepiness Scale (ESS). Further we examine the correlations between sleep and pain. METHODS: Patients who underwent permanent SCS implantation completed six validated questionnaires to compare sleep patterns, pain intensity, and quality of life at baseline and six months postoperatively. Results were analyzed via paired samples t-tests and bivariate analysis. RESULTS: Data from 27 patients were collected. We saw a significant decrease in ISI scores (n = 23, t(df)=2.9(22), p = 0.008), and noted a trend in the percentage improvement between ISI and ESS (n = 12, t(df)=2.0(10), p = 0.078). We did not see any significant improvement in ESS. However, improvements in insomnia correlated with pain intensity as measured through visual analog scale score and McGill Pain Questionnaire (R = 0.546, p = 0.007 and R = 0.559, p = 0.006, respectively). DISCUSSION: We demonstrate that insomnia scores on ISI improve with SCS at six-month follow-up. Further, we find that improvements in pain correlate with these ISI improvements.

Pedometry as an External Measure of Spinal Cord Stimulation Patient Outcomes.

BACKGROUND: Chronic pain is a debilitating biologic and psychologic condition which affects nearly one third of the American population with an annual cost of $560 to $635 billion from associated health care costs and lost productivity. Treatment of chronic pain is difficult to objectively evaluate as it relies on subjective measure. An objective measure would be beneficial in assessing treatment efficacy and towards developing a closed loop system. We assess the efficacy of pedometry as an objective measure of treatment efficacy in spinal cord stimulation (SCS). METHODS: Participants who had back and/or leg pain and were scheduled for permanent thoracic SCS implantation were offered inclusion. Preoperatively and at three months post-operatively, patients underwent a battery of tests including the Oswestry Disability Index (ODI), Pain Catastrophization Scale (PCS), McGill Pain Questionnaire-Short Form (MPQ), Likert Pain Scale, Visual Analog Scale (VAS), Insomnia Severity Scale (ISS), and Epworth Sleepiness Scale (ESS). They also wore a pedometer for 48 hours prior to SCS implantation and for 48 hours at three months. Walking distance, step count, and steps per hour were documented. Additionally, patients were asked to record their activity level in hours per day. RESULTS: Eight patients completed three month follow-up. All measurements of disability and pain decreased significantly: ODI (p = 0.004), PCS (p = 0.01), MPQ (p = 0.02), VAS (p = 0.001), ISS (p = 0.002), and ESS (p = 0.041). All pain and disability measurements decreased independent of activity measures, except lowest levels of pain at the patient's best. A positive correlation was found between improvement in participant's active time and improvement in ESS score, suggesting decreased daytime sleepiness with increased time spent active (r = 0.844, N = 7, p = 0.017). CONCLUSIONS: We demonstrate a mean improvement of more than 50% in distance walked, steps per hour, and total steps. Interestingly, total activity (number of hours spent active per day) was not dramatically improved. Our data suggests that as a group our patients' ambulation increased dramatically after successful SCS. The use of pedometry in conjunction with self-reporting can lend both quantitative and qualitative validity to pain, as well as allow objective assessment of efficacy of SCS in patients suffering from chronic low back and/or leg pain. Further, external sensors tracking these data may be a means of creating a closed loop system with SCS.

A Prospective Study of the Intra- and Postoperative Efficacy of Intraoperative Neuromonitoring in Spinal Cord Stimulation.

BACKGROUND: Accurate lead placement is critical for spinal cord stimulation (SCS) efficacy. The traditional gold standard of awake placement is often technically difficult. While there is retrospective evidence supporting the use of intraoperative neurophysiological monitoring (IOM) as an alternative, a prospective assessment has not yet been performed. OBJECTIVE: To prospectively evaluate pain and functionality outcomes for IOM-guided SCS, validate two IOM modalities as a means to lateralize lead placement and assess whether IOM can be useful for postoperative programming. METHODS: A total of 73 patients were implanted with SCS using electromyography (EMG) and somatosensory-evoked potential collision studies (SSEP-CS) to verify lead placement. Patient pain and function were assessed through serial administration of several validated questionnaires. Stimulation parameters at 6 months were documented. RESULTS: Statistically significant (p < 0.05) improvements were observed in the McGill Pain Questionnaire, Oswestry Disability Index, Pain Catastrophizing Scale, and Visual Analog Scale. EMG and SSEP-CS appropriately lateralized leads in 65/73 (89.0%) and 40/58 (69.0%) cases, respectively. EMG predicted active contacts in use at follow-up with 82.7% sensitivity. CONCLUSIONS: We provide prospective evidence that IOM can be used to verify SCS placement. Additionally, EMG may help to streamline device programming and thereby improve outcomes by predicting the ideal stimulation contacts in many cases.

Predictors of Spinal Cord Stimulation Success.

INTRODUCTION: As many as 30% of spinal cord stimulation (SCS) patients fail to obtain long-term pain coverage, even with the strictest parameters of a successful trial, unremarkable psychological assessment, and ideal placement of the permanent device. Why these patients either never receive adequate benefit or lose benefit remains elusive. METHODS: We perform a retrospective review of our prospective database of SCS patients undergoing surgery for routine indications. Six-month postoperative follow-up data were available for 57 patients. Two providers who routinely saw the patients were asked to independently grade the patient's outcome in a blinded fashion on a Global Outcome Ratings scale of 1 to 10, with 5 being 50% improvement at 6 months postoperation. A score of less than 5 was deemed a failure. The impact of body mass index (BMI), random drug screen results, workers' compensation status, depression, and smoking were assessed. RESULTS: We report a phi correlation of 0.350 between smoking and failure (p = 0.017). Smoking status is correlated with both lead migration revisions (phi = 0.269) (p = 0.044) and with revision due to new pain symptoms (phi = 0.241) (p = 0.072). Further, there is a trend of correlation (phi = 0.289) between drug use and patients (N = 3) who underwent device removal (p = 0.045). In this cohort, worker's compensation status, BMI, and depression did not impact outcome. CONCLUSIONS: Tobacco use correlates with less success with SCS at 6-month follow-up. Whether that is because of issues with healing and our transmission of signals to the periphery warrants further exploration. These data provide further evidence that tobacco cessation is important to surgical results.

Biomimetic aryl hydroxylation derived from alkyl hydroperoxide at a nonheme iron center. Evidence for an Fe(IV)=O oxidant.

Many nonheme iron-dependent enzymes activate dioxygen to catalyze hydroxylations of arene substrates. Key features of this chemistry have been developed from complexes of a family of tetradentate tripodal ligands obtained by modification of tris(2-pyridylmethyl)amine (TPA) with single alpha-arene substituents. These included the following: -C(6)H(5) (i.e., 6-PhTPA), L(1); -o-C(6)H(4)D, o-d(1)-L(1); -C(6)D(5), d(5)-L(1); -m-C(6)H(4)NO(2), L(2); -m-C(6)H(4)CF(3), L(3); -m-C(6)H(4)Cl, L(4); -m-C(6)H(4)CH(3), L(5); -m-C(6)H(4)OCH(3), L(6); -p-C(6)H(4)OCH(3), L(7). Additionally, the corresponding ligand with one alpha-phenyl and two alpha-methyl substituents (6,6-Me(2)-6-PhTPA, L(8)) was also synthesized. Complexes of the formulas [(L(1))Fe(II)(NCCH(3))(2)](ClO(4))(2), [(L(n)())Fe(II)(OTf)(2)] (n = 1-7, OTf = (-)O(3)SCF(3)), and [(L(8))Fe(II)(OTf)(2)](2) were obtained and characterized by (1)H NMR and UV-visible spectroscopies and by X-ray diffraction in the cases of [(L(1))Fe(II)(NCCH(3))(2)](ClO(4))(2), [(L(6))Fe(II)(OTf)(2)], and [(L(8))Fe(II)(OTf)(2)](2). The complexes react with tert-butyl hydroperoxide ((t)()BuOOH) in CH(3)CN solutions to give iron(III) complexes of ortho-hydroxylated ligands. The product complex derived from L(1) was identified as the solvated monomeric complex [(L(1)O(-))Fe(III)](2+) in equilibrium with its oxo-bridged dimer [(L(1)O(-))(2)Fe(III)(2)(mu(2)-O)](2+), which was characterized by X-ray crystallography as the BPh(4)(-) salt. The L(8) product was also an oxo-bridged dimer, [(L(8)O(-))(2)Fe(III)(2)(mu(2)-O)](2+). Transient intermediates were observed at low temperature by UV-visible spectroscopy, and these were characterized as iron(III) alkylperoxo complexes by resonance Raman and EPR spectroscopies for L(1) and L(8). [(L(1))Fe(II)(OTf)(2)] gave rise to a mixture of high-spin (S = 5/2) and low-spin (S = 1/2) Fe(III)-OOR isomers in acetonitrile, whereas both [(L(1))Fe(OTf)(2)] in CH(2)Cl(2) and [(L(8))Fe(OTf)(2)](2) in acetonitrile afforded only high-spin intermediates. The L(1) and L(8) intermediates both decomposed to form respective phenolate complexes, but their reaction times differed by 3 orders of magnitude. In the case of L(1), (18)O isotope labeling indicated that the phenolate oxygen is derived from the terminal peroxide oxygen via a species that can undergo partial exchange with exogenous water. The iron(III) alkylperoxo intermediate is proposed to undergo homolytic O-O bond cleavage to yield an oxoiron(IV) species as an unobserved reactive intermediate in the hydroxylation of the pendant alpha-aryl substituents. The putative homolytic chemistry was confirmed by using 2-methyl-1-phenyl-2-propyl hydroperoxide (MPPH) as a probe, and the products obtained in the presence and in the absence of air were consistent with formation of alkoxy radical (RO(*)). Moreover, when one ortho position was labeled with deuterium, no selectivity was observed between hydroxylation of the deuterated and normal isotopomeric ortho sites, but a significant 1,2-deuterium shift ("NIH shift") occurred. These results provide strong mechanistic evidence for a metal-centered electrophilic oxidant, presumably an oxoiron(IV) complex, in these arene hydroxylations and support participation of such a species in the mechanisms of the nonheme iron- and pterin-dependent aryl amino acid hydroxylases.

Peripheral Palladium(II) and Platinum(II) Complexes of Bis(dimethylamino)porphyrazine.

The unsymmetrical porphyrazine (tetraazaporphyrin) bearing a single peripheral bis(dimethylamino) functionality, Mg[pz(NMe(2))(2)(Pr)(6)], was prepared by base-catalyzed cross condensation of dipropyl maleonitrile (in excess) with dimethylamino maleonitrile. The freebase (2H[pz(NMe(2))(2)(Pr)(6)]) and centrally metalated forms (M[pz(NMe(2))(2)(Pr)(6)]; M = Ni(II), Cu(II), Mn(III)) were prepared by treatment of Mg[pz(NMe(2))(2)(Pr)(6)] with trifluoroacetic acid and then the appropriate metal salt. PdCl(2) and PtCl(2) were coordinated to the peripheral bis(dimethylamino) chelates, yielding the bimetallic complexes, M[pz(NMe(2))(2)(Pr)(6)]M'Cl(2) (M = Ni, Cu; M' = Pd, Pt). The heteroleptic [N(2)-Pd-S(2)]-capped porphyrazines were prepared readily by substituting the chloride ions of M[pz(NMe(2))(2)(Pr)(6)]PdCl(2) with the dithiolene chelates, maleonitriledithiolate (mnt(2)(-)), benzenedithiolate (bdt(2)(-)), and 1,3-dithiole-2-one-4,5-dithiolate (dmid(2)(-)). The [N(2)-Pt-S(2)] complexes were prepared by reaction of M[pz(NMe(2))(2)(Pr)(6)]PtCl(2) with the dialkyltin-protected dithiolates dibutyltin(toluene-3,4-dithiolate) and dibutyltin(dmit). The peripheral heteroleptic [N(2)-M'-S(2)] core was found to be electroactive for electron-rich dithiolene ligands (bdt(2)(-), E(1/2)(Pd(III)/Pd(II)) = 0.22 V; tdt(2)(-), E(1/2)(Pt(III)/Pt(II)) = 0.20 V; dmid(2)(-), E(1/2)(Pd(III)/Pd(II)) = 0.19 V; dmit(2)(-), E(1/2)(Pt(III)/Pt(II)) = 0.19 V) but not for the relatively electron-poor dithiolene, maleonitriledithiolate (mnt(2)(-)). The X-ray structure of Ni[pz(NMe(2))(2)(Pr)(6)]Pd(mnt) (13) was determined. Crystal data for C(85)H(109)Cl(3)N(24)Ni(2)Pd(2)S(4): space group P2(1)/n; a = 17.435(4) Å, b = 17.982(2) Å, c = 30.577(2) Å; beta = 104.27(2) degrees; Z = 4.