Early ventilator liberation and decreased sedation needs after tracheostomy in patients with COVID-19 infection

Background

Since the outset of the coronavirus disease 2019 (COVID-19) pandemic, published tracheostomy guidelines have generally recommended deferral of the procedure beyond the initial weeks of intubation given high mortality as well as concerns about transmission of the infection to providers. It is unclear whether tracheostomy in patients with COVID-19 infection facilitates ventilator weaning, and long-term outcomes are not yet reported in the literature.

Methods

This is a retrospective study of tracheostomy outcomes in patients with COVID-19 infection at a single-center academic tertiary referral intensive care unit. Patients underwent percutaneous tracheostomy at the bedside; the procedure was performed with limited staffing to reduce risk of disease transmission.

Results

Between March 1 and June 30, 2020, a total of 206 patients with COVID-19 infection required mechanical ventilation and 26 underwent tracheostomy at a mean of 25±5 days after initial intubation. Overall, 81% of tracheostomy patients were liberated from the ventilator at a mean of 9±6 days postprocedure, and 54% were decannulated prior to hospital discharge at a mean of 21±10 days postprocedure. Sedation and pain medication requirements decreased significantly in the week after the procedure. In-hospital mortality was 15%. Among tracheostomy survivors, 68% were discharged to a facility.

Discussion

The management of patients with COVID-19 related respiratory failure can be challenging due to prolonged ventilator dependency. In our initial experience, outcomes post-tracheostomy in this population are encouraging, with short time to liberation from the ventilator, a high rate of decannulation prior to hospital discharge, and similar mortality to tracheostomy performed for other indications. Barriers to weaning ventilation in this cohort may be high sedation needs and ventilator dyssynchrony.

Level of evidence

Level V-Therapeutic/care management.

"And if you gaze long into an abyss, the abyss gazes also into thee": four morphs of Arctic charr adapting to a depth gradient in Lake Tinnsjøen

The origin of species is a central topic in biology. Ecological speciation might be a driver in adaptive radiation, providing a framework for understanding mechanisms, level, and rate of diversification. The Arctic charr Salvelinus alpinus L. is a polymorphic species with huge morphological and life‐history diversity in Holarctic water systems. We studied adaptive radiation of Arctic charr in the 460‐m‐deep Lake Tinnsjøen to (a) document eco‐morphology and life‐history traits of morphs, (b) estimate reproductive isolation of morphs, and (c) illuminate Holarctic phylogeography and lineages colonizing Lake Tinnsjøen. We compared Lake Tinnsjøen with four Norwegian outgroup populations. Four field‐assigned morphs were identified in Lake Tinnsjøen: the planktivore morph in all habitats except deep profundal, the dwarf morph in shallow‐moderate profundal, the piscivore morph mainly in shallow‐moderate profundal, and a new undescribed abyssal morph in the deep profundal. Morphs displayed extensive life‐history variation in age and size. A moderate‐to‐high concordance was observed among morphs and four genetic clusters from microsatellites. mtDNA suggested two minor endemic clades in Lake Tinnsjøen originating from one widespread colonizing clade in the Holarctic. All morphs were genetically differentiated at microsatellites (F_ST: 0.12–0.20), associated with different mtDNA clade frequencies. Analyses of outgroup lakes implied colonization from a river below Lake Tinnsjøen. Our findings suggest postglacial adaptive radiation of one colonizing mtDNA lineage with niche specialization along a depth–temperature–productivity–pressure gradient. Concordance between reproductive isolation and habitats of morphs implies ecological speciation as a mechanism. Particularly novel is the extensive morph diversification with depth into the often unexplored deepwater profundal habitat, suggesting we may have systematically underestimated biodiversity in lakes. In a biological conservation framework, it is imperative to protect endemic below‐species‐level biodiversity, particularly so since within‐species variation comprises an extremely important component of the generally low total biodiversity observed in the northern freshwater systems.

Safe and effective use of alitretinoin in children with recalcitrant hand eczema and other dermatoses - a retrospective analysis

BACKGROUND

Alitretinoin is a systemic retinoid licensed for use in adult patients suffering from chronic hand eczema recalcitrant to potent topical steroids. Experience with its use in childhood is lacking.

OBJECTIVES

To report on the efficacy and safety of alitretinoin treatment in a cohort of children and adolescents with chronic hand eczema (CHE) and other inflammatory skin diseases.

METHODS

We performed a retrospective chart review of all consecutive patients under the age of 18 years treated with alitretinoin at our paediatric skin centre. Physician's Global Assessment (PGA) was used as the primary outcome measure.

RESULTS

Thirteen children (9 girls and 4 boys) were enrolled in this study. The median age at start of treatment with alitretinoin was 11.5 years (range 5.8-15.8 years). Nine children were diagnosed with CHE, two with severe atopic dermatitis (AD), and two with inherited ichthyosis [netherton syndrome (NS), autosomal recessive congenital ichthyosis (ARCI)]. Moderate to excellent response (PGA decrease of ≥1 point) was observed in 7 (78%) of the nine patients with CHE, one of the two patients with extensive AD and in the one patient with ARCI. In the remaining four subjects, no convincing effect was documented. Tolerability was overall very good. The most common adverse event was headache in 10 patients (77%) during the initiation of treatment, leading to interruption of therapy in one subject.

CONCLUSIONS

Alitretinoin seems to be highly effective and safe for the treatment of paediatric CHE and should thus be considered in children with refractory disease under topical therapy. Larger studies are required to corroborate these findings.

Transverse Anderson localization of surface plasmon polaritons

We investigate the effect of disorder on the propagation of surface plasmon polaritons in arrays of evanescently coupled dielectric loaded surface plasmon polariton waveguides. Diagonal disorder is implemented by randomly varying the heights of the waveguides. Real-space as well as momentum-space images of the surface plasmon polariton intensity distribution in the waveguide arrays are recorded by leakage radiation microscopy. In real space, increasing disorder results in a transverse localization of surface plasmon polaritons. In the momentum distribution, we observe for the first time a disorder-induced transition from a continuous band to a set of discrete modes.

[PASTA-lesions--debridement versus repair]

BACKGROUND

Partial articular supraspinatus tendon avulsions (PASTA) lesions remain challenging with regard to diagnosis and treatment.

DIAGNOSTICS

For the diagnosis of PASTA lesions, arthroscopic evaluation of the supraspinatus tendon is key. Preoperative imaging alone is usually not sufficient to make the treatment decision.

OPERATIVE TECHNIQUE

For non-significant partial tears of less than 50 % of the tendon thickness a simple debridement is indicated. Two basic repair techniques, a transtendon repair technique and a repair after tear completion, can be distinguished. In PASTA lesions, a repair is generally preferred to debridement.

RESULTS

Results in the literature do not favor one repair technique over the other. Prospective randomized trials comparing debridement with repair are lacking in the literature. From a technical standpoint tear completion and repair seem to be a bit more reproducible.

α-Aminoxylation of ketones and β-chloro-α-aminoxylation of enones with TEMPO and chlorocatecholborane

Oxidation of various cyclic and acyclic ketones under mild conditions with chlorocatecholborane, a bulky pyridine base, and TEMPO to the corresponding α-aminoxylated products in good to excellent yields (52-99%) is described. For enones as substrates, products of a β-chloro-α-aminoxylation are obtained (70-89%).

Catalytic asymmetric thiofunctionalization of unactivated alkenes

Catalytic asymmetric sulfenylation of double bonds has been achieved using a BINAM-based phosphoramide catalyst and an electrophilic sulfur source. Simple alkenes as well as styrenes afforded sulfenylated tetrahydrofurans and tetrahydropyrans by closure with pendant hydroxyl or carboxyl groups. Intermolecular thiofunctionalizations were also achieved with simple alcohols or carboxylic acids as the nucleophiles.

[Diverticulum of the ductus arteriosus. Cause of traumatic aortic ruptures?]

INTRODUCTION

According to angiographic studies 9-26% of all adult aortae show a ductus arteriosus diverticulum (DAD), i.e. an indention of the aortic wall at the insertion of the obliterated ductus arteriosus. This region is predisposed for traumatic aortic rupture. Up to now fixation at the transition from aorta transversa to fixed aorta descendens is regarded as cause. It is unclear whether ductus diverticulum favours traumatic aortic rupture.

MATERIAL AND METHODS

A total of 143 thoracic aortas (female symbol:37; male symbol:106, 17-91 years) were scanned histomorphologically for DAD. Calcification was quantified by CT multislice volume scan.

RESULTS

A DAD was detected in 44% of macroscopically non-calcified and slightly calcified aortic specimens. Histologically, autochthonal elastic and collagenous fibres of the media were disrupted. CT in macroscopically non-calcified aortas proved isolated calcification in 78%.

DISCUSSION

The incidence of 44% DAD-higher than in angiographic studies-can be explained by the method (histopathology), allowing diagnosis of diverticula down to microm. These morphological alterations are to be seen, at least in part, as a causative factor for the predilection to traumatic aortic ruptures.

A simple cobalt catalyst system for the efficient and regioselective cyclotrimerisation of alkynes

The intermolecular cyclotrimerisation of terminal and internal alkynes can be catalysed by simple cobalt complexes such as a CoBr2(diimine) under mild reaction conditions when treated with zinc and zinc iodide with high regioselectivity in excellent yields.

Stereoselective Synthesis of (+)-Nephrosteranic Acid, (+)-trans-Cognac Lactone, and (+)-trans-Whisky Lactone using a Chiral Cyclohexadienyl Ti Compound

We present the stereoselective transfer of cyclohexadienyl from 3-metalated 1,4-cyclohexadienes to various aldehydes. Lewis-acid-mediated "allylation" of aldehydes by treatment with 3-silylated and 3-stannylated 1,4-cyclohexadienes could not be achieved with high diastereoselectivity. In contrast, cyclohexadienyl titanium compounds reacted with both aliphatic and aromatic aldehydes with good-to-excellent diastereoselectivities. Reaction of a chiral TADDOL-derived (TADDOL, 2,2-dimethyl-alpha,alpha,alpha',alpha'-tetraphenyl-1,3-dioxolandimethanol) cyclohexadienyl Ti derivative with various aldehydes led to the corresponding homoallylic alcohols with excellent diastereo- and enantioselectivities. Lower selectivities were obtained with chiral B-cyclohexadienyldiisopinocampheylborane. The 1,3-cyclohexadienes are very useful building blocks for the preparation of biologically important gamma-butyrolactones. Short efficient syntheses of (+)-nephrosteranic acid, (+)-trans-whisky lactone, and (+)-trans-cognac lactone by desymmetrization of 1,4-cyclohexadiene are described.