Residual neuromuscular blockade in the ICU: a prospective observational study and national survey.

Residual neuromuscular blockade is associated with significant morbidity. It has been widely studied in anaesthesia; however, the incidence of residual neuromuscular blockade in patients managed in the ICU is unknown. We conducted a prospective observational study in a tertiary ICU to determine the incidence of residual neuromuscular blockade using quantitative accelerographic monitoring. We tested for residual neuromuscular blockade (defined as a train-of-four ratio < 0.9) before cessation of sedation in anticipation of tracheal extubation. We also surveyed 16 other ICUs in New Zealand to determine their use of neuromuscular monitoring. A total of 191 patients were included in the final analysis. The incidence (95%CI) of residual neuromuscular blockade was 43% (36-50%), with a similar incidence observed in non-postoperative and postoperative patients. There was a lower risk of residual neuromuscular blockade with atracurium than rocuronium (risk ratio (95%CI) of 0.39 (0.12-0.78)) and a higher risk with pancuronium than rocuronium (1.59 (1.06-2.49)). Our survey shows that, in New Zealand ICUs, monitoring of neuromuscular function is rarely carried out before tracheal extubation. When neuromuscular monitoring is undertaken, it is based on individual clinician suspicion and performed using qualitative measurements. No ICU reported using a quantitative monitor or a clinical guideline. The results demonstrate a high incidence of residual neuromuscular blockade in our ICU patients and identify the type of neuromuscular blocking drug as a possible risk factor. Monitoring neuromuscular function before tracheal extubation is not currently the standard of care in New Zealand ICUs. These data suggest that residual neuromuscular blockade may be an under-recognised problem in ICU practice.

Application of dynamic modelling techniques to the problem of antibacterial use and resistance: a scoping review.

Selective pressure exerted by the widespread use of antibacterial drugs is accelerating the development of resistant bacterial populations. The purpose of this scoping review was to summarise the range of studies that use dynamic models to analyse the problem of bacterial resistance in relation to antibacterial use in human and animal populations. A comprehensive search of the peer-reviewed literature was performed and non-duplicate articles (n = 1486) were screened in several stages. Charting questions were used to extract information from the articles included in the final subset (n = 81). Most studies (86%) represent the system of interest with an aggregate model; individual-based models are constructed in only seven articles. There are few examples of inter-host models outside of human healthcare (41%) and community settings (38%). Resistance is modelled for a non-specific bacterial organism and/or antibiotic in 40% and 74% of the included articles, respectively. Interventions with implications for antibacterial use were investigated in 67 articles and included changes to total antibiotic consumption, strategies for drug management and shifts in category/class use. The quality of documentation related to model assumptions and uncertainty varies considerably across this subset of articles. There is substantial room to improve the transparency of reporting in the antibacterial resistance modelling literature as is recommended by best practice guidelines.

Salmonella Thompson outbreak associated with consumption of chicken shawarma and the usefulness of genome sequencing in the investigation.

BACKGROUND: A sudden increase in Salmonella Thompson (S. Thompson) cases distributed throughout three border regions in the province of Quebec in November 2016 triggered a provincial investigation to identify a common source of contamination and to put the appropriate control measures into place. OBJECTIVE: To report on the outbreak and to describe the use of genomic sequencing to identify the salmonella serotype responsible. METHODS: A descriptive survey of all reported cases of Salmonella serogroup C1 that had occurred between October 1, 2016 and February 15, 2017 was conducted. A case definition was developed. Pulsed field gel electrophoresis supplemented by analyses of genome sequences using the single nucleotide variant phylogenomics method were used to demarcate and manage the outbreak. RESULTS: Eighteen cases of S. Thompson were identified through whole genome sequencing. The onset dates of symptoms for the 16 cases that presented enteric symptoms were November 21-December 2, 2016. Two cases that presented with atypical symptoms were not reported until February 2017. Among the 18 cases, 16 had eaten or probably eaten chicken shawarma at the same restaurant chain and nine of these cases ate it at the same restaurant. In total, five restaurants from this chain, spread throughout three border regions of Quebec, were identified. CONCLUSION: Outbreaks associated with chicken shawarma have been identified in the past. Efforts must be made to ensure that the owners of this type of restaurant know the contamination risk associated with this type of cooking and take the necessary steps to reduce this risk. The use of the genome sequencing method was very useful in defining the outbreak.

Usefulness of High-Quality Core Genome Single-Nucleotide Variant Analysis for Subtyping the Highly Clonal and the Most Prevalent Salmonella enterica Serovar Heidelberg Clone in the Context of Outbreak Investigations.

Salmonella enterica serovar Heidelberg is the second most frequently occurring serovar in Quebec and the third-most prevalent in Canada. Given that conventional pulsed-field gel electrophoresis (PFGE) subtyping for common Salmonella serovars, such as S. Heidelberg, yields identical subtypes for the majority of isolates recovered, public health laboratories are desperate for new subtyping tools to resolve highly clonal S. Heidelberg strains involved in outbreak events. As PFGE was unable to discriminate isolates from three epidemiologically distinct outbreaks in Quebec, this study was conducted to evaluate whole-genome sequencing (WGS) and phylogenetic analysis as an alternative to conventional subtyping tools. Genomes of 46 isolates from 3 Quebec outbreaks (2012, 2013, and 2014) supported by strong epidemiological evidence were sequenced and analyzed using a high-quality core genome single-nucleotide variant (hqSNV) bioinformatics approach (SNV phylogenomics [SNVphyl] pipeline). Outbreaks were indistinguishable by conventional PFGE subtyping, exhibiting the same PFGE pattern (SHEXAI.0001/SHEBNI.0001). Phylogenetic analysis based on hqSNVs extracted from WGS separated the outbreak isolates into three distinct groups, 100% concordant with the epidemiological data. The minimum and maximum number of hqSNVs between isolates from the same outbreak was 0 and 4, respectively, while >59 hqSNVs were measured between 2 previously indistinguishable outbreaks having the same PFGE and phage type, thus corroborating their distinction as separate unrelated outbreaks. This study demonstrates that despite the previously reported high clonality of this serovar, the WGS-based hqSNV approach is a superior typing method, capable of resolving events that were previously indistinguishable using classic subtyping tools.

Modeling the pattern of contrast extravasation in acute intracerebral hemorrhage using dynamic contrast-enhanced MR.

BACKGROUND: Contrast extravasation (CE) in spontaneous intracerebral hemorrhage (ICH), coined the spot sign, predicts hematoma expansion (HE) and poor clinical outcome. The dynamic relationship between CE and the mode of ICH growth are poorly understood. We characterized the in vivo pattern and rate of HE using a novel animal model of acute ICH. METHODS: Basal ganglia ICH was created in 14 Yorkshire swine utilizing a novel MRI integrated model, permitting real-time CE observation using dynamic contrast-enhanced (DCE) MRI. Computerized planimetry measured CE volume at each time point. Spatial vector analysis along three orthogonal axes determined distance vectors. Maximizing and minimizing the coefficient of determination defined the temporal phases of growth and stability, respectively. CE rate was calculated using a Patlak model. RESULTS: Asymmetric growth and variable rates of expansion characterized HE defining three distinct growth phases and patterns. A primary growth phase (duration 160 s; IQR 50-130) demonstrated rapid linear growth (0.04 mm/s IQR 0.01-0.10) accounting for 85 ± 15 % of total HE. The stationary phase demonstrated stability (duration 145 s; IQR 0-655). A secondary growth phase (duration 300; 130-600 s) accounted for 23 ± 8 % of total HE. In the primary and secondary growth phase, asymmetric growth occurred in the anterior-posterior (AP) planes (0.056 mm/s; p = 0.026 and 0.0112 mm/s; p = 0.03). Monophasic 2 (14 %), biphasic 4 (35 %) (primary followed by secondary growth), and triphasic 8 (56 %) patterns (primary, stationary, and secondary growth phase) were observed. CONCLUSIONS: A novel model of ICH provides real-time study of the dynamics and rate of CE. This data facilitates the understanding of pattern and rate of ICH formation.

An in vivo, MRI-integrated real-time model of active contrast extravasation in acute intracerebral hemorrhage.

BACKGROUND AND PURPOSE: The "spot sign" or contrast extravasation is strongly associated with hematoma formation and growth. An animal model of contrast extravasation is important to test existing and novel therapeutic interventions to inform present and future clinical studies. The purpose of this study was to create an animal model of contrast extravasation in acute intracerebral hemorrhage. MATERIALS AND METHODS: Twenty-eight hemispheres of Yorkshire male swine were insonated with an MR imaging-guided focused sonography system following lipid microsphere infusion and mean arterial pressure elevation. The rate of contrast leakage was quantified by using dynamic contrast-enhanced MR imaging and was classified as contrast extravasation or postcontrast leakage by using postcontrast T1. Hematoma volume was measured on gradient recalled-echo MR imaging performed 2 hours postprocedure. Following this procedure, sacrificed brain was subjected to histopathologic examination. Power level, burst length, and blood pressure elevation were correlated with leakage rate, hematoma size, and vessel abnormality extent. RESULTS: Median (intracerebral hemorrhage) contrast extravasation leakage was higher than postcontrast leakage (11.3; 6.3-23.2 versus 2.4; 1.1-3.1 mL/min/100 g; P<.001). Increasing burst length, gradient recalled-echo hematoma (ρ=0.54; 95% CI, 0.2-0.8; P=.007), and permeability were correlated (ρ=0.55; 95% CI, 0.1-0.8; P=.02). Median permeability (P=.02), gradient recalled-echo hematoma (P=.02), and dynamic contrast-enhanced volumes (P=.02) were greater at 1000 ms than at 10 ms. Within each burst-length subgroup, incremental contrast leakage was seen with mean arterial pressure elevation (ρ=0.2-0.8). CONCLUSIONS: We describe a novel MR imaging-integrated real-time swine intracerebral hemorrhage model of acute hematoma growth and contrast extravasation.

MELAS: A Multigenerational Impact of the MTTL1 A3243G MELAS Mutation.

BACKGROUND: the maternally inherited MTTL1 A3243G mutation in the mitochondrial genome causes MelaS (Mitochondrial encephalopathy lactic acidosis with Stroke-like episodes), a condition that is multisystemic but affects primarily the nervous system. Significant intra-familial variation in phenotype and severity of disease is well recognized. METHODS: retrospective and ongoing study of an extended family carrying the MTTL1 A3243G mutation with multiple symptomatic individuals. tissue heteroplasmy is reviewed based on the clinical presentations, imaging studies, laboratory findings in affected individuals and pathological material obtained at autopsy in two of the family members. RESULTS: there were seven affected individuals out of thirteen members in this three generation family who each carried the MTTL1 A3243G mutation. the clinical presentations were varied with symptoms ranging from hearing loss, migraines, dementia, seizures, diabetes, visual manifestations, and stroke like episodes. three of the family members are deceased from MelaS or to complications related to MelaS. CONCLUSIONS: the results of the clinical, pathological and radiological findings in this family provide strong support to the current concepts of maternal inheritance, tissue heteroplasmy and molecular pathogenesis in MelaS. neurologists (both adult and paediatric) are the most likely to encounter patients with MelaS in their practice. genetic counselling is complex in view of maternal inheritance and heteroplasmy. newer therapeutic options such as arginine are being used for acute and preventative management of stroke like episodes.

A population-based study of antipsychotic prescription trends in children and adolescents in British Columbia, from 1996 to 2011.

OBJECTIVES: To establish prevalence rates of antipsychotic (AP) prescriptions for children 18 years of age or younger in British Columbia (BC) from 1996 to 2011 by age, sex, AP type, and primary diagnosis; and to identify the predominant AP prescribers for children by specialty training. METHODS: BC Ministry of Health administrative data were used to describe AP prescriptions for youth aged 18 years or younger. Comparisons were made using population prevalence based on sex; age group; AP; International Classification of Diseases, Ninth Revision, diagnosis; and prescriber specialty. RESULTS: From 1996 to 2011, overall AP (both first and second generation) prescription prevalence rate increased 3.8-fold (1.66 to 6.37 per 1000 population); second-generation AP (SGA) prescriptions increased 18.1-fold (0.33 to 5.98 per 1000 population). The highest increase in all AP prescriptions occurred in males aged 13 to 18 years (3.3 to 14.4 per 1000 population; 4.4-fold), followed by similar increases in males aged 6 to 12 years (2.3 to 8.6 per 1000 population; 3.7-fold) and in females aged 13 to 18 years (2.8 to 10.7 per 1000 population; 3.8-fold). Overall, the 3 most common diagnoses associated with all AP prescriptions were depressive disorders (12.8%), hyperkinetic syndrome of childhood (11.7%), and neurotic disorders (11.1%); however, variation was observed by prescriber specialty training. Among all new AP prescriptions in 2010/11, 38.6%, 34.3%, and 15.6% were provided by psychiatrists, family physicians, and pediatricians, respectively. CONCLUSIONS: There has been an exponential rise in SGA prescriptions in BC secondary to extensive off-label use, not only by psychiatrists but also by family physicians and pediatricians. Knowledge translation initiatives promoting evidence-based prescribing and monitoring practices related to SGA treatment need to target all 3 prescriber groups and be tailored for age subgroups.

Objectifs : Établir les taux de prévalence des prescriptions d'antipsychotiques (AP) à des enfants et des adolescents de 18 ans et moins en Colombie-Britannique (C.-B.) de 1996 à 2011 selon l'âge, le sexe, le type d'AP, et le diagnostic primaire; et identifier les prescripteurs d'AP prédominants pour les enfants par formation de spécialité. Méthodes : Les données administratives du ministère de la Santé de la C.-B. ont servi à décrire les prescriptions d'AP à des adolescents de 18 ans ou moins. Des comparaisons ont été effectuées au moyen de la prévalence de la population selon le sexe, le groupe d'âge, les AP, la 9e édition de la Classification internationale des maladies, le diagnostic, et la spécialité du prescripteur. Résultats : De 1996 à 2011, le taux global de prévalence des prescriptions d'AP (de la première et de la deuxième génération) a augmenté 3,8 fois (1,66 à 6,37 par 1000 de population); les prescriptions d'AP de deuxième génération (ADG) ont augmenté 18,1 fois (0,33 à 5,98 par 1000 de population). L'augmentation la plus élevée de toutes les prescriptions d'AP a touché les jeunes hommes de 13 à 18 ans (3,3 à 14,4 par 1000 de population; soit 4,4 fois plus), suivie par des augmentations semblables chez les garçons de 6 à 12 ans (2,3 à 8,6 par 1000 de population; soit 3,7 fois plus) et chez les filles de 13 à 18 ans (2,8 à 10,7 par 1000 de population; soit 3,8 fois plus). En général, les 3 diagnostics les plus communs associés à toutes les prescriptions d'AP étaient les troubles dépressifs (12,8 %), l'instabilité de l'enfance (11,7 %), et les troubles névrotiques (11,1 %); toutefois, une variation a été observée dans la formation de spécialité du prescripteur. Parmi toutes les nouvelles prescriptions d'AP en 2010-2011, 38,6 %, 34,3 %, et 15,6 % ont été fournies par des psychiatres, des médecins de famille, et des pédiatres, respectivement. Conclusions : Il y a eu une hausse exponentielle des prescriptions d'ADG en C.-B., consécutive à une vaste utilisation non indiquée sur l'étiquette, non seulement par les psychiatres mais aussi les médecins de famille et les pédiatres. Les initiatives de transmission des connaissances qui prônent des pratiques de prescription et de surveillance fondées sur les données probantes et reliées au traitement par ADG doivent cibler les 3 groupes de prescripteurs et être adaptées aux sous-groupes d'âge.

Cyclospora cayetanensis: a description of clinical aspects of an outbreak in Quebec, Canada.

Cyclospora cayetanensis is an emerging infectious agent. The aim of this study was to describe an outbreak that occurred in 250 adults exposed to contaminated food, focusing on the duration and relapses of symptoms, complications and evidence of local transmission. This outbreak affected workers who ate in a restaurant in June 2005. Cyclospora sp. was observed in the stools of 20 cases and 122 probable cases were identified. The attack rate was estimated at 89%. Main symptoms were diarrhoea (96%), nausea (88%), fatigue (87%), abdominal cramps (85%), fever (52%) and headaches (45%). Contaminated fresh basil originating from a Mexican farm, used to prepare an uncooked appetizer, was identified as the source. In this non-endemic population of immunocompetent adults, Cyclospora infection presents with watery diarrhoea lasting from 4 to 18 days and fatigue lasting from 11 to 42 days. For a small proportion of affected persons, recovery can be delayed.

The effect of an anterior biteplate on dental and skeletal Class II correction using headgears: a cephalometric study.

OBJECTIVE: To test the hypothesis that there are significant differences in skeletal and/or dental changes between Class II subjects treated with headgear (HG) compared with those treated with HG plus maxillary acrylic biteplate (BP) discluding teeth. SETTING AND SAMPLE POPULATION: Secondary analysis performed in Department of Orthodontics at the University of Washington. Fifty pre-adolescent Class II subjects were treated with HG as part of a randomized clinical trial (RCT) at the University of North Carolina/Chapel Hill, and 81 similar subjects were treated with HG plus a flatplane maxillary anterior BP for occlusal separation and anterior labial bow at the University of Florida as part of a separate RCT. MATERIAL AND METHODS: This retrospective cohort study examined anteroposterior (AP) and vertical cephalometric changes in two cohorts of Class II subjects. Pre- and post-treatment cephalometric radiographs for each group were obtained from the two centers and measured for dental and skeletal changes. These data were adjusted for differences in magnification and compared using ancova, controlling for important cohort and protocol differences between the two centers. RESULTS: Overbite and maxillary incisor inclinations were reduced significantly more in the HG/BP group. All other vertical and AP changes were not statistically significantly different between the groups. CONCLUSION: The maxillary anterior BP with labial bow is an effective appliance for reducing overbite and retracting incisors but provides no additional AP dental or skeletal benefit over HG treatment.

[Delirious psychiatric nurse with abdominal pain - a medical chameleon]. / Deliranter Psychiatriepfleger mit Bauchschmerzen - Ein medizinisches Chamäleon.

Acute hepatic porphyrias stand for a group of rare genetic defects in the metabolism of heme biosynthesis, whereof acute intermittent porphyria is the most frequent one. Factors like drugs, infections, fasting, alcohol, or stress can provoke an acute crisis. The symptoms are very variable; however gastrointestinal and neuro-psychiatric symptoms are common. Furthermore darkening urine might be an important diagnostic sign. We describe the case of a 33-year-old psychiatric nurse presenting with stomach ache, hypertension, delirium and red spots in his underwear.

Investigation of acute lower gastrointestinal bleeding with 16- and 64-slice multidetector CT.

We evaluated the usefulness of 16- and 64-slice multidetector CT (MDCT) in the detection of a bleeding site in acute lower gastrointestinal tract (GIT) haemorrhage by conducting a retrospective study of cases of presumed acute lower GIT haemorrhage imaged with CT in two teaching hospitals in an 11-month period. The patients underwent contrast enhanced CT using either a 16 or 64 MDCT. No oral contrast was used. One hundred milliliters of non-ionic intravenous contrast agent was injected at 4.5 mL/s, followed by a 60 mL saline flush at 4 mL/s through a dual head injector. Images were acquired in arterial phase with or without non-contrast and portal phase imaging with 16 x 1.5 mm or 64 x 0.625 mm collimation. Active bleeding was diagnosed by the presence of iodinated contrast extravasation into the bowel lumen on arterial phase images with attenuation greater than and distinct from the normal mucosal enhancement or focal pooling of increased attenuation contrast material within a bowel segment on portal-venous images. Further management and final diagnosis was recorded. Fourteen patients and 15 studies were reviewed. CT detected and localized a presumed bleeding site or potential causative pathology in 12 (80%) of the patients. Seven of these were supported by other investigations or surgery, while five were not demonstrated by other modalities. Eight patients had mesenteric angiography, of which only four corroborated the site of bleeding. CT did not detect the bleeding site in three patients, of which two required further investigation and definitive treatment. We propose that MDCT serves a useful role as the initial rapid investigation to triage patients presenting with lower GIT bleeding for further investigation and management.

Non-invasive prediction of the degree of liver fibrosis in patients with hepatitis C using an ultrasound contrast agent. A pilot study.

It has been shown that the severity of hepatic fibrosis in patients with hepatitis C can be predicted non-invasively by measuring intrahepatic circulatory time (IHCT) using a microbubble agent with spectral Doppler analysis. The aim of this study was to assess whether this technique is reproducible using a third-generation microbubble agent and contrast harmonic imaging, which are becoming the standard ultrasound techniques in all radiology departments. Twenty-three untreated patients with hepatitis C, who had undergone a recent liver biopsy, were studied prospectively. Based on their histological fibrosis score, patients were divided into four groups (fibrosis levels 1-4). Contrast harmonic imaging was carried out after an intravenous bolus of a microbubble agent (Optison; Amersham Health, Milwaukee, WI, USA). IHCT was calculated by measuring the difference between the hepatic vein and hepatic artery microbubble arrival times. The IHCT was compared with the degree of fibrosis. Significant differences were shown between the groups for IHCT. There were significant differences between fibrosis levels 1 and 3 and between fibrosis levels 1 and 4. This study has shown that calculation of IHCT using a third-generation microbubble agent and contrast harmonic imaging can differentiate mild fibrosis from more severe degrees of fibrosis in patients with hepatitis C.

Natural animal shaking: a model for non-accidental head injury in children?

BACKGROUND: Non-accidental head injury (NAHI) is a form of child abuse where a perpetrator may violently subject an infant to repeated acceleration-deceleration forces with or without head impact, producing injuries including retinal haemorrhages in most cases. Animal models have included laboratory shaking of mice and rats, but only a small fraction develop retinal haemorrhages presumably due to the small eyes, which would require unattainable force levels to mimic that sustained by the infant eye. Animal models are also problematic due to ethical issues raised by subjecting even anaesthetized animals to abusive injury. METHODS: We investigated a naturally occurring event, where three animal victims were shaken by a canine. The eyes were harvested and examined histologically. RESULTS: The victims' eyes showed no haemorrhage or retinoschisis. CONCLUSIONS: Our model may not be a complete NAHI mimic. The discrepancies may ensue from anatomical and mechanical differences in the injury mechanism. Other models must be sought to further study this form of abusive eye injury.

Left main coronary artery 'embolectomy' using a novel, straightforward technique.

A 60-year-old man experienced catastrophic haemodynamic decompensation 3 days following coronary artery bypass grafting (CABG). Aspiration thrombectomy to remove a left main coronary artery saddle embolus resulted in immediate haemodynamic improvement with no requirement for angioplasty or repeat bypass grafting. Coronary thromboembolism should be considered in the differential diagnosis of haemodynamic collapse post CABG. Urgent coronary angiography and aspiration thrombectomy may result in significant improvement for this condition.

Studies of collisional selection rules in thioformaldehyde (H2CS) by microwave-optical double resonance.

Individual rotational levels in the A 1A2,v4=1 state of thioformaldehyde (H2CS) are excited by a cw laser and microwave transitions in the region of 8-12 GHz are measured. Some of the microwave frequencies are found to be characteristic of rotational levels other than the level being pumped. Since the microwave frequencies are characteristic of individual rotational levels in the excited state and the excited-state lifetime is approximately 170 micros, information is obtained concerning rotational selection rules during collisions. It is found that J can change by several units and Ka by 0, +/-2, +/-4, and +/-6. The latter result confirms that o-H2CS is not converted to p-H2CS by collisions. Observation of Ka doublets indicates that there are no appreciable differences between the two components.