Neurological complications of excessive recreational nitrous oxide use: a case series based on a text mining algorithm.

BACKGROUND: The recreational use of nitrous oxide (N2O) has gained popularity over recent years. We present a case series of excessive N2O users with neurological complications. METHODS: In this retrospective three-centre study, we used a text mining algorithm to search for patients who used N2O recreationally and visited a neurologist. RESULTS: We identified 251 patients. The median duration of N2O use was 11 months (interquartile range [IQR], 3-24) and the median amount of N2O used per occasion 1.6 kg (IQR 0.5-4.0). Clinically, polyneuropathy (78%), myelopathy (41%), and encephalopathy (14%) were the most common diagnoses. An absolute vitamin B12 deficiency of < 150 pmol/L was found in 40% of cases. In 90%, at least one indicator of functional vitamin B12 status (vitamin B12, homocysteine, or methylmalonic acid) was abnormal. MRI showed signs of myelopathy in 30/55 (55%) of cases. In 28/44 (64%) of those who underwent electromyography, evidence of axonal polyneuropathy was found. Most (83%) patients were treated with vitamin B12 supplementation, and 23% were admitted to the hospital. Only 41% had follow-up for ≥ 30 days, and 79% of those showed partial or complete recovery. CONCLUSIONS: In this case series of excessive N2O users, we describe a high prevalence of polyneuropathy, myelopathy, and encephalopathy. Stepwise testing for serum levels of vitamin B12, homocysteine, and methylmalonic acid may support the clinical diagnosis. Due to low sensitivity, MRI of the spinal cord and electromyography have limited value. Effective treatment should incorporate supplementation of vitamin B12 and strategies to prevent relapses in N2O use.

The patient-reported outcomes measurement information systems (PROMIS®) physical function and its derivative measures in adults: a systematic review of content validity.

PURPOSE: This study aims to systematically review and critically appraise the content validity of the adult versions of the Patient-Reported Outcomes Measurement Information System Physical Function (PROMIS-PF) item bank and its derivative measures in any adult population. METHODS: MEDLINE and EMBASE were searched in October 2021 for studies on measurement properties of PROMIS-PF measures in an adult population. Studies were included if the study described the development of a PROMIS-PF measure or investigated its relevance, comprehensiveness, or comprehensibility. Assessment of the methodological quality of eligible studies, rating of results, and summarizing evidence was performed following the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) methodology for assessing content validity. A modified GRADE approach was used to determine the level of evidence. RESULTS: Three development studies and eight studies on the content validity of one or more of the PROMIS-PF measures were identified. The methodological quality of most studies was rated doubtful. There was low to high level evidence for sufficient relevance, comprehensiveness, and comprehensibility of most PROMIS-PF measures for healthy seniors and various disease populations. We found low to moderate level evidence for insufficient relevance of PROMIS-PF measures for patients with conditions that affected only one body part, and insufficient comprehensibility of the PROMIS-PF measures for minority elderly. CONCLUSION: Most PROMIS-PF measures demonstrate sufficient content validity in healthy seniors and various disease populations. However, the quality of this evidence is generally low to moderate, due to limitations in the methodological quality of the studies.

Transition of care in stroke patients discharged home: a single-center prospective cohort study.

INTRODUCTION: Approximately two-thirds of the patients admitted to the hospital with an ischemic stroke are discharged directly home. Discontinuity of care may result in avoidable patient harm, re-admissions and even death. We hypothesized that the transfer of information is most essential in this patient group since any future care for these patients relies solely on the information that is available to the care provider responsible at that time. AIM: The objective of this study was to evaluate the continuity of transmural care in ischemic stroke patients by assessing 1) the transfer of clinical information through discharge letters to general practitioners (GPs), 2) subsequent documentation of this information and early follow-up by GPs and 3) the documentation of medication-related information in discharge letters, at GPs and community pharmacies (CPs). METHODS: This prospective cohort study was conducted from September 2019 through March 2020 in OLVG, Amsterdam, the Netherlands, in patients with a first stroke discharged directly home. Outcome measures were derived from national guidelines and regional agreements. Results were analyzed using descriptive analysis. RESULTS: A total of 33 patients were included. Discharge letters (n = 33) and outpatient clinic letters (n = 24) to GPs contained most of the essential items, but 16% (n = 9) of the letters were sent in time. GPs (n = 31) infrequently adhered to guidelines since 10% (n = 3) of the diagnoses were registered using the correct code and 55% (n = 17) of the patients received follow-up shortly after discharge. Medication overviews were inaccurately communicated to GPs since 62% (n = 150) of all prescriptions (n = 243) were correctly noted in the discharge letter. Further loss of information was seen as only 39% (n = 95) of all prescriptions were documented correctly in GP overviews. We found that 59% (n = 144) of the prescriptions were documented correctly in CP overviews. CONCLUSION: In this study, we found that discontinuity of care occurred to a varying extent throughout transmural care in patients with a first stroke who were discharged home.

Bacterial aetiology and mortality in COPD patients with CAP: results from the German Competence Network, CAPNETZ.

BACKGROUND: Community-acquired pneumonia (CAP) is a major cause of morbidity and mortality, and chronic obstructive pulmonary disease (COPD) is a frequent comorbidity. The bacterial aetiology of CAP-COPD and its possible associations with serum markers and mortality are incompletely understood. OBJECTIVES: 1) To assess the bacterial aetiology of CAP only and CAP-COPD, and 2) to study the association between bacterial aetiology, empirical antibiotic treatment, serum markers and mortality. METHODS: Of 1288 patients with CAP (57.0% males, age 59.0 years ± 18.5), 262 (20.3%) fulfilled the diagnostic criteria for COPD. Differences between subgroups were investigated using univariate analyses and corrected for multiple comparisons. RESULTS: Streptococcus pneumoniae was the most common pathogen (30.8% CAP only vs. 26.0% CAP-COPD, not significant). Haemophilus influenzae was significantly more frequent in CAP-COPD (5.6% CAP only vs. 26.0% CAP-COPD, P < 0.001). The number given adequate empirical antibiotic treatment was comparable (83.3% CAP only vs. 83.6% CAP-COPD, P > 0.05). The CAP-COPD group had worse CURB-65 and partial pressure of arterial oxygen levels than the CAP only group (P < 0.001). Partial pressure of arterial carbon dioxide levels were increased in CAP-COPD patients without pathogen detection (P < 0.001). Short- (P = 0.011) and long-term mortality (P = 0.006) were highest in CAP-COPD without pathogen detection. CONCLUSION: It is important to identify COPD patients with CAP. In particular, those without bacterial pathogen detection have more severe CAP and are at higher risk of dying. Better understanding of the aetiology could contribute to improved management and treatment of CAP in COPD patients.

Aspirated bile: a major host trigger modulating respiratory pathogen colonisation in cystic fibrosis patients.

Chronic respiratory infections are a leading global cause of morbidity and mortality. However, the molecular triggers that cause respiratory pathogens to adopt persistent and often untreatable lifestyles during infection remain largely uncharacterised. Recently, bile aspiration caused by gastro-oesophageal reflux (GOR) has emerged as a significant complication associated with respiratory disease, and cystic fibrosis (CF) in particular. Based on our previous finding that the physiological concentrations of bile influence respiratory pathogens towards a chronic lifestyle in vitro, we investigated the impact of bile aspiration on the lung microbiome of respiratory patients. Sputum samples (n = 25) obtained from a cohort of paediatric CF patients were profiled for the presence of bile acids using high-resolution liquid chromatography-mass spectrometry (LC-MS). Pyrosequencing was performed on a set of ten DNA samples that were isolated from bile aspirating (n = 5) and non-bile aspirating (n = 5) patients. Both denaturing gradient gel electrophoresis (DGGE) and pyrosequencing revealed significantly reduced biodiversity and richness in the sputum samples from bile aspirating patients when compared with non-aspirating patients. Families and genera associated with the pervasive CF microbiome dominated aspirating patients, while bacteria associated with the healthy lung were most abundant in non-aspirating patients. Bile aspiration linked to GOR is emerging as a major host trigger of chronic bacterial infections. The markedly reduced biodiversity and increased colonisation by dominant proteobacterial CF-associated pathogens observed in the sputum of bile aspirating patients suggest that bile may play a major role in disease progression in CF and other respiratory diseases.

Biomechanical responses of the back of riding horses to water treadmill exercise.

There is a lack of evidence for the presumed beneficial effects of water treadmills on the movement of the horse's back. The aim of the study was to evaluate the effects of water treadmill exercise on axial rotation (AR), lateral bending (LB) and pelvic flexion (PF) in horses. The back kinematics of a group of riding horses were studied at the walk in a water treadmill at different depths of water (hoof, fetlock, carpus, elbow and shoulder joint levels) over a period of 10 days. Skin markers were placed at anatomical locations on the back. AR, LB and PF were measured on days 1 and 10 using two high-speed video cameras. There was a significant increase in AR compared to baseline at the level of the carpus and at higher water levels, whereas LB was significantly lower than baseline values at water levels that reached the elbow and shoulder joints. PF was significantly higher than baseline values at each water depth other than hoof water depth. At increasing water depths, there were significant increases in flexion and rotation of the back. At the highest water levels, there was reduced bending of the back. After 10 days, horses exhibited more bending of the back.

The non-classical ArsR-family repressor PyeR (PA4354) modulates biofilm formation in Pseudomonas aeruginosa.

PyeR (PA4354) is a novel member of the ArsR family of transcriptional regulators and modulates biofilm formation in Pseudomonas aeruginosa. Characterization of this regulator showed that it has negative autoregulatory properties and binds to a palindromic motif conserved among PyeR orthologues. These characteristics are in line with classical ArsR-family regulators, as is the fact that PyeR is part of an operon structure (pyeR-pyeM-xenB). However, PyeR also exhibits some atypical features in comparison with classical members of the ArsR family, as it does not harbour metal-binding motifs and does not appear to be involved in metal perception or resistance. Hence, PyeR belongs to a subgroup of non-classical ArsR-family regulators and is the second ArsR regulator shown to be involved in biofilm formation.

Characterization of imipenem resistance mechanisms in Pseudomonas aeruginosa isolates from Turkey.

The emergence of carbapenem resistance in Pseudomonas aeruginosa threatens the efficacy of this important anti-pseudomonal antibiotic class. Between 2003 and 2006, an increase in the number of carbapenem-resistant P. aeruginosa isolates at the Zonguldak Karaelmas University Hospital was observed (Zonguldak, Turkey). To assess the imipenem resistance mechanisms emerging in these P. aeruginosa isolates, they were characterized by amplified fragment length polymorphism typing, which revealed diversity among imipenem-resistant isolates as well as two clonally related outbreak groups. The molecular mechanism of carbapenem resistance was characterized in a representative isolate from each clonal group. Mutational disruption of oprD was the most frequently encountered resistance mechanism (23/27 isolates).

Class 1 integrons in ciprofloxacin-resistant Escherichia coli strains from two Dutch hospitals.

A significant increase in the isolation frequency of ciprofloxacin-resistant Escherichia coli was observed in the haematology departments of two university hospitals in The Netherlands. Amplified fragment length polymorphism analysis revealed that this increase was not caused by the emergence of unique ciprofloxacin-resistant clones. Determination of the presence of class 1 integrons indicated that 81% of the ciprofloxacin-resistant isolates contained an intI1 gene, compared with 11% of the ciprofloxacin-susceptible isolates (p<0.0001). The quinolone resistance gene qnrA was not present in any of the integrons characterised and could not be detected using dot-blot hybridisation of total DNA. In addition, conjugation experiments showed that ciprofloxacin resistance was not co-transferred with class 1 integrons. Ciprofloxacin-resistant isolates harboured mutations in the gyrA gene, which are known to encode ciprofloxacin resistance. In conclusion, an association was observed between ciprofloxacin resistance and the presence of class 1 integrons, which could not be explained by the currently known genetic determinants of quinolone resistance.