Role of overnight oximetry in assessing the severity of obstructive sleep apnoea in typically developing children: a multicentre study.

BACKGROUND AND OBJECTIVE: Cardiorespiratory polygraphy (CRP) is the predominant technology used to diagnose obstructive sleep apnoea (OSA) in tertiary centres in the UK. Nocturnal pulse oximetry (NPO) is, however, cheaper and more accessible. This study evaluated the ability of NPO indices to predict OSA in typically developing (TD) children. METHODS: Indices from simultaneous NPO and CRP recordings were compared in TD children (aged 1-16 years) referred to evaluate OSA in three tertiary centres. OSA was defined as an obstructive apnoea-hypopnoea index (OAHI) ≥1 event/hour. Receiver operating characteristic curves assessed the diagnostic accuracy of NPO indices including ODI3 (3% Oxygen Desaturation Index, ODI4 (4% Oxygen Desaturation Index), delta 12 s index and minimum oxygen saturation. Two-by-two tables were generated to determine the sensitivities and specificities of whole number cut-off values for predicting OAHIs ≥1, 5 and 10 events/hour. RESULTS: Recordings from 322 TD children, 197 male (61.2%), median age 4.9 years (range 1.1-15.6), were reviewed. OAHI was ≥1/hour in 144 (44.7%), ≥5/hour in 61 (18.9%) and ≥10/hour in 28 (8.7%) cases. ODI3 and ODI4 had the best diagnostic accuracy. ODI3 ≥7/hour and ODI4 ≥4/hour predicted OSA in TD children with sensitivities/specificities of 57.6%/85.4% and 46.2%/91.6%, respectively. ODI3 ≥8/hour was the best predictor of OAHI ≥5/hour (sensitivity 82.0%, specificity 84.3%). CONCLUSION: Raised ODI3 and ODI4 predict OSA in TD children with high specificity but variable sensitivity. NPO may be an alternative to diagnose moderate-severe OSA if access to CRP is limited. Low sensitivities to detect mild OSA mean that confirmatory CRP is needed if NPO is normal.

Phage therapy: Awareness and demand among clinicians in the United Kingdom.

Bacterial resistance or tolerance to antibiotics is costly to patients and healthcare providers. With the impact of antibiotic resistance forecast to grow, alternative antimicrobial approaches are needed to help treat patients with antibiotic refractory infections and reduce reliance upon existing antibiotics. There is renewed interest in bacteriophage (phage) therapy as a promising antimicrobial strategy. We therefore performed the first multi-specialty survey about phage therapy and the first such survey among clinicians in the United Kingdom. An anonymous 10-question survey of clinicians from medical and surgical specialties in two Scottish Health Boards was performed. The 90 respondents spanned 26 specialties and were predominantly consultants (73.3%). The respondents were concerned about antibiotic resistance in their clinical practice; 83 respondents estimated having seen 711 patients in the last 12 months whose infections were refractory to antibiotics (delaying or preventing resolution). Over half (58.8%) of the respondents had previously heard of phage therapy. Staphylococci, Pseudomonas and E. coli were identified as the highest cross-specialty priorities for the development of phage therapy. Together, 77 respondents estimated seeing 300 patients in the last 12 months for whom phage therapy may have been appropriate (an average of 3.9 patients per clinician). Most respondents (71.1%, n = 90) were already willing to consider using phage therapy in appropriate cases. Additional comments from the respondents affirmed the potential utility of phage therapy and highlighted a need for more information. The results of this survey demonstrate substantial demand for and willingness to use phage therapy in appropriate cases, both from individual clinicians and across specialties. Demand from a wide range of specialties illustrates the broad clinical utility of phage therapy and potential scope of impact. Widening access to phage therapy could deliver substantial clinical and financial benefits for patients and health authorities alike.

Managing Patient and Clinician Expectations of Phage Therapy in the United Kingdom.

Bacteriophage (phage) therapy is a promising alternative antimicrobial approach which has the potential to transform the way we treat bacterial infections. Phage therapy is currently being used on a compassionate basis in multiple countries. Therefore, if a patient has an antibiotic refractory infection, they may expect their clinician to consider and access phage therapy with the hope of improvement. The expectations of clinicians may be similar and may also include expectations around data collection. However, there are multiple biological and practical barriers to fulfilling patient and clinician expectations. While it is possible to access phage therapy, the path to acquisition is not straightforward and expectations therefore need to be managed appropriately to avoid raising false hope and undermining confidence in phage therapy. Phage scientists have an important contribution to make in educating clinicians and the broader public about phage therapy. However, it is clinicians that are responsible for managing the expectations of their patients and this relies on clear communication about the barriers and limitations.

Indirect effects of the COVID-19 pandemic on paediatric healthcare use and severe disease: a retrospective national cohort study.

OBJECTIVES: To determine the indirect consequences of the COVID-19 pandemic on paediatric healthcare utilisation and severe disease at a national level following lockdown on 23 March 2020. DESIGN: National retrospective cohort study. SETTING: Emergency childhood primary and secondary care providers across Scotland; two national paediatric intensive care units (PICUs); statutory death records. PARTICIPANTS: 273 455 unscheduled primary care attendances; 462 437 emergency department attendances; 54 076 emergency hospital admissions; 413 PICU unplanned emergency admissions requiring invasive mechanical ventilation; and 415 deaths during the lockdown study period and equivalent dates in previous years. MAIN OUTCOME MEASURES: Rates of emergency care consultations, attendances and admissions; clinical severity scores on presentation to PICU; rates and causes of childhood death. For all data sets, rates during the lockdown period were compared with mean or aggregated rates for the equivalent dates in 2016-2019. RESULTS: The rates of emergency presentations to primary and secondary care fell during lockdown in comparison to previous years. Emergency PICU admissions for children requiring invasive mechanical ventilation also fell as a proportion of cases for the entire population, with an OR of 0.52 for likelihood of admission during lockdown (95% CI 0.37 to 0.73), compared with the equivalent period in previous years. Clinical severity scores did not suggest children were presenting with more advanced disease. The greatest reduction in PICU admissions was for diseases of the respiratory system; those for injury, poisoning or other external causes were equivalent to previous years. Mortality during lockdown did not change significantly compared with 2016-2019. CONCLUSIONS: National lockdown led to a reduction in paediatric emergency care utilisation, without associated evidence of severe harm.

The curious incident of groaning in the night-time.

The first report of catathrenia in a child who has been symptomatic from birth http://ow.ly/XcY830bevOH.

The presumed central nervous system effects of rocuronium in a neonate and its reversal with sugammadex.

We describe a 2-day-old male infant who received rocuronium as part of general anesthesia for a tracheal esophageal fistula repair. Postoperatively, he had prolonged central and peripheral neuromuscular blockade despite cessation of the rocuronium infusion several hours previously. This case discusses the presumed central nervous system effects of rocuronium in a neonate and its effective reversal with sugammadex.

Covalent dimer species of beta-defensin Defr1 display potent antimicrobial activity against multidrug-resistant bacterial pathogens.

Beta defensins comprise a family of cationic, cysteine-rich antimicrobial peptides, predominantly expressed at epithelial surfaces. Previously we identified a unique five-cysteine defensin-related peptide (Defr1) that, when synthesized, is a mixture of dimeric isoforms and exhibits potent antimicrobial activity against Escherichia coli and Pseudomonas aeruginosa. Here we report that Defr1 displays antimicrobial activity against an extended panel of multidrug-resistant nosocomial pathogens for which antimicrobial treatment is limited or nonexistent. Defr1 fractions were collected by high-pressure liquid chromatography and analyzed by gel electrophoresis and mass spectrometry. Antimicrobial activity was initially investigated with the type strain Pseudomonas aeruginosa PAO1. All fractions tested displayed equivalent, potent antimicrobial activity levels comparable with that of the unfractionated Defr1. However, use of an oxidized, monomeric six-cysteine analogue (Defr1 Y5C), or of reduced Defr1, gave diminished antimicrobial activity. These results suggest that the covalent dimer structure of Defr1 is crucial to antimicrobial activity; this hypothesis was confirmed by investigation of a synthetic one-cysteine variant (Defr1-1cys). This gave an activity profile similar to that of synthetic Defr1 but only in an oxidized, dimeric form. Thus, we have shown that covalent, dimeric molecules based on the Defr1 beta-defensin sequence demonstrate antimicrobial activity even in the absence of the canonical cysteine motif.

Structure-activity relationships in defensin dimers: a novel link between beta-defensin tertiary structure and antimicrobial activity.

Defensins are cationic antimicrobial peptides that have a characteristic six-cysteine motif and are important components of the innate immune system. We recently described a beta-defensin-related peptide (Defr1) that had potent antimicrobial activity despite having only five cysteines. Here we report a relationship between the structure and activity of Defr1 through a comparative study with its six cysteine-containing analogue (Defr1 Y5C). Against a panel of pathogens, we found that oxidized Defr1 had significantly higher activity than its reduced form and the oxidized and reduced forms of Defr1 Y5C. Furthermore, Defr1 displayed activity against Pseudomonas aeruginosa in the presence of 150 mm NaCl, whereas Defr1 Y5C was inactive. By using nondenaturing gel electrophoresis and Fourier transform ion cyclotron resonance mass spectrometry, we observed Defr1 and Defr1 Y5C dimers. Two complementary fragmentation techniques (collision-induced dissociation and electron capture dissociation) revealed that Defr1 Y5C dimers form by noncovalent, weak association of monomers that contain three intramolecular disulfide bonds. In contrast, Defr1 dimers are resistant to collision-induced dissociation and are only dissociated into monomers by reduction using electron capture. This is indicative of Defr1 dimerization being mediated by an intermolecular disulfide bond. Proteolysis and peptide mass mapping revealed that Defr1 Y5C monomers have beta-defensin disulfide bond connectivity, whereas oxidized Defr1 is a complex mixture of dimeric isoforms with as yet unknown inter- and intramolecular connectivities. Each isoform contains one intermolecular and four intramolecular disulfide bonds, but because we were unable to resolve the isoforms by reverse phase chromatography, we could not assign each isoform with a specific antimicrobial activity. We conclude that the enhanced activity and stability of this mixture of Defr1 dimeric isoforms are due to the presence of an intermolecular disulfide bond. This first description of a covalently cross-linked member of the defensin family provides further evidence that the antimicrobial activity of a defensin is linked to its ability to form stable higher order structures.

Lack of correlation between O-serotype, bacteriophage susceptibility and genomovar status in the Burkholderia cepacia complex.

The Burkholderia cepacia complex comprises at least nine phylogenetically related genomic species (genomovars) which cause life-threatening infection in immunocompromised humans, particularly individuals with cystic fibrosis or chronic granulomatous disease. Prior to recognition that 'B. cepacia' comprise multiple species, in vitro studies revealed that the lipopolysaccharide (LPS) of these Gram-negative bacteria is strongly endotoxic. In this study, we used 117 B. cepacia complex isolates to determine if there is a correlation between O-antigen serotype and genomovar status. Isolates were also tested for their ability to act as bacterial hosts for the LPS-binding bacteriophages NS1 and NS2. The absence of genomovar II (Burkholderia multivorans) in 'historical B. cepacia' isolates was notable. Neither O-serotype nor phage susceptibility correlated with genomovar status. We conclude that variability in LPS may contribute to the success of these highly adaptable bacteria as human pathogens.