Use of point-of-care ultrasound in rural British Columbia: Scale, training, and barriers.

OBJECTIVE: To determine the scale and scope of use of point-of-care ultrasound (POCUS) in rural British Columbia (BC). DESIGN: Online survey. SETTING: Rural BC. PARTICIPANTS: Physicians practising in rural BC communities. MAIN OUTCOME MEASURES: Practitioner demographic and practice characteristics, locations and frequency of POCUS use, POCUS education and training, and practitioner attitudes about and barriers to POCUS use. RESULTS: Two hundred twenty-seven surveys were completed in fall 2021, corresponding to a response rate of 11.9% of all rural practitioners in BC. A total of 52.1% of respondents worked in communities with less than 10,000 people, while 24.9% had practices with relatively large proportions of Indigenous patients (more than 20% of the practice population). Respondents reported ease of access to local POCUS devices, with use highest in emergency departments (87.2%) followed by ambulatory care clinic (54.7%) and inpatient (50.3%) settings. Use of POCUS influenced clinical decision making in half the occasions in which it was employed, including a range of diagnostic and procedural applications. Barriers to use included lack of training, limited time to perform POCUS scans, and absence of image review or consultative support. Needed support for POCUS identified by respondents included real-time image acquisition advice and funding for both device acquisition and training. Recommendations for including POCUS training in undergraduate and residency education were strongly supported. CONCLUSION: Use of POCUS in BC is expanding in frequency, scope, and scale in practices serving rural areas and in rural communities with large Indigenous populations, with practitioners reporting important improvements in clinical care as a result. Future research could help improve systemic support for POCUS use, guide needed curriculum changes in medical school and postgraduate training, and be used to inform continuing professional development needs.

Brief diesel exhaust exposure acutely impairs functional brain connectivity in humans: a randomized controlled crossover study.

BACKGROUND: While it is known that exposure to traffic-related air pollution causes an enormous global toll on human health, neurobiological underpinnings therein remain elusive. The study addresses this gap in knowledge. METHODS: We performed the first controlled human exposure study using functional MRI with an efficient order-randomized double-blind crossover study of diesel exhaust (DE) and control (filtered air; FA) in 25 healthy adults (14 males, 11 females; 19-49 years old; no withdrawals). Analyses were carried out using a mixed effects model in FLAME. Z (Gaussianised T/F) statistic images were thresholded non-parametrically using clusters determined by Z > 2.3 and a (corrected) cluster significance threshold of p = 0.05. RESULTS: All 25 adults went through the exposures and functional MRI imaging were collected. Exposure to DE yielded a decrease in functional connectivity compared to exposure to FA, shown through the comparison of DE and FA in post-exposure measurement of functional connectivity. CONCLUSION: We observed short-term pollution-attributable decrements in default mode network functional connectivity. Decrements in brain connectivity causes many detrimental effects to the human body so this finding should guide policy change in air pollution exposure regulation. TRIAL REGISTRATION: University of British Columbia Clinical Research Ethics Board (# H12-03025), Vancouver Coastal Health Ethics Board (# V12-03025), and Health Canada's Research Ethics Board (# 2012-0040).

Feasibility of patient-controlled analgesia (PCA) for rural and remote transfers.

BACKGROUND: In rural Canada, the majority of prehospital care is provided by basic life support paramedics, who cannot administer opioids or parenteral analgesics. Patients requiring transfer to a higher level of care have limited options for pain control. We aim to determine if ambulance-based patient-controlled analgesia (PCA) is feasible during inter-facility transfers. METHODS: This is a prospective non-consecutive cohort feasibility study conducted in the East Kootenay region of British Columbia from 2016 to 2020. Patients in acute pain from an illness or injury requiring an opioid and transfer to a higher level of care were offered PCA. The study used respiratory depression as a marker of safety, assessed if PCA during transport provided efficacious analgesia, measured satisfaction scores from patients and paramedics, and tracked adverse events. RESULTS: 84 patients received PCA. The majority had orthopaedic trauma and the average transfer time was 3 h 22 min. The average pain score at the start and end of the transfer was unchanged, at 4 out of 10. Patient and paramedic satisfaction scores at the end of the transfer were 4.6 and 4.7 out of 5, respectively. Three out of the 84 patients (3.6%) had desaturation episodes below or equal to 90% oxygen saturation; however, all resolved with supplemental oxygen. INTERPRETATION: Ambulance-based PCA is feasible and has a high level of satisfaction among paramedics and patients. It has significant potential for inter-facility transport in rural regions in Canada where ambulances are staffed with paramedics who cannot administer opioids or other parenteral analgesics.

RéSUMé: CONTEXTE: Dans les régions rurales du Canada, la majorité des soins préhospitaliers sont prodigués par des ambulanciers paramédicaux essentiels qui ne peuvent administrer d'opioïdes ou d'analgésiques parentéraux. Les patients nécessitant un transfert vers un niveau de soins supérieur ont des options limitées pour le contrôle de la douleur. Notre objectif est de déterminer si l'analgésie contrôlée par le patient (ACP) en ambulance est possible lors des transferts entre établissements. MéTHODES: Il s'agit d'une étude de faisabilité prospective de cohorte non consécutive menée dans la région de Kootenay Est en Colombie-Britannique de 2016 à 2020. Les patients souffrant de douleurs aiguës dues à une maladie ou à une blessure nécessitant un opioïde et un transfert vers un niveau de soins supérieur se sont vu proposer une APC. L'étude a utilisé la dépression respiratoire comme marqueur de sécurité, a évalué si l'ACP pendant le transport fournissait une analgésie efficace, a mesuré les scores de satisfaction des patients et du personnel paramédical, et a suivi les événements indésirables. RéSULTATS: 84 patients ont reçu une ACP. La majorité avait un traumatisme orthopédique et le temps de transfert moyen était de 3 h 22 min. Le score moyen de douleur au début et à la fin du transfert était inchangé, à 4 sur 10. Les scores de satisfaction des patients et des ambulanciers paramédicaux à la fin du transfert étaient de 4,6 et 4,7 sur 5, respectivement. Trois des 84 patients (3,6%) ont connu des épisodes de désaturation inférieurs ou égaux à 90% de saturation en oxygène; cependant, tous se sont résorbés avec l'apport d'oxygène supplémentaire. INTERPRéTATION: L'ACP en ambulance est faisable et présente un haut niveau de satisfaction parmi les paramédicaux et les patients. Il présente un potentiel important pour le transport inter-établissements dans les régions rurales du Canada où les ambulances sont dotées de personnel paramédical qui ne peut pas administrer d'opioïdes ou d'autres analgésiques parentéraux.

An Investigation into Which Methods Best Explain Children's Exposure to Traffic-Related Air Pollution.

There have been several methods employed to quantify individual-level exposure to ambient traffic-related air pollutants (TRAP). These include an individual's residential proximity to roads, measurement of individual pollutants as surrogates or markers, as well as dispersion and land use regression (LUR) models. Hopanes are organic compounds still commonly found on ambient particulate matter and are specific markers of combustion engine primary emissions, but they have not been previously used in personal exposure studies. In this paper, children's personal exposures to TRAP were evaluated using hopanes determined from weekly integrated filters collected as part of a personal exposure study in Windsor, Canada. These hopane measurements were used to evaluate how well other commonly used proxies of exposure to TRAP performed. Several of the LUR exposure estimates for a range of air pollutants were associated with the children's summer personal hopane exposures (r = 0.41-0.74). However, all personal hopane exposures in summer were more strongly associated with the length of major roadways within 500 m of their homes. In contrast, metrics of major roadways and LUR estimates were poorly correlated with any winter personal hopanes. Our findings suggest that available TRAP exposure indicators have the potential for exposure misclassification in winter vs. summer and more so for LUR than for metrics of major road density. As such, limitations are evident when using traditional proxy methods for assigning traffic exposures and these may be especially important when attempting to assign exposures for children's key growth and developmental windows. If long-term chronic exposures are being estimated, our data suggest that measures of major road lengths in proximity to homes are a more-specific approach for assigning personal TRAP exposures.

Evaluating delays for emergent CT scans from a rural British Columbia hospital.

OBJECTIVES: Computed Tomography (CT) scans help diagnose and triage life-threatening and time-sensitive emergency conditions, but most rural hospitals in British Columbia do not have access to a local CT scanner. We investigate how many transfers from a rural British Columbia hospital were for CT scans and describe the time delays to emergent CT imaging. METHODS: This was a prospective cohort study, over a 1-year period, on all patients requiring a transfer from the Golden and District Hospital, located 247 km from the closest CT scanner. Data collection forms were completed prospectively and the main measurements included age, transport triage level, reason for transfer, referral hospital, transfer request time, and CT scan time. The time interval between the CT request and CT imaging was calculated and represents the 'delay to CT scan' interval. RESULTS: The study hospital received 8672 emergency department (ED) visits and 220 were transferred to referral centres (2.5%). 61% of all transfers received a CT scan. Transfers for time-sensitive emergencies took an average of 6 h 52 min. Patients with acute stroke experienced a 4 h 44 min time interval. Less urgent and non-urgent conditions entailed an even greater time delay. CONCLUSIONS: This study highlights that the lack of a rural CT scanner is associated with increased transfers and significant time delays. Improving access to CT scanners for rural communities may be one of the many steps in addressing healthcare disparities between rural and urban communities.

RéSUMé: OBJECTIFS: La tomodensitométrie (TDM) aide à diagnostiquer et à trier les situations d'urgence qui mettent la vie en danger et pour lesquelles le temps est compté, mais la plupart des hôpitaux ruraux de la Colombie-Britannique n'ont pas accès à un tomodensitomètre local. Nous enquêtons sur le nombre de transferts d'un hôpital rural de la Colombie-Britannique pour des tomodensitogrammes et nous décrivons les délais pour l'imagerie tomographique émergente. MéTHODES: Il s'agit d'une étude de cohorte prospective, sur une période d'un an, sur tous les patients nécessitant un transfert de l'hôpital de Golden and district, situé à 247 km du scanner le plus proche. Les formulaires de collecte de données ont été remplis de manière prospective et les principales mesures comprenaient l'âge, le niveau de triage de transport, la raison du transfert, l'hôpital de référence, le temps de demande de transfert et le temps de tomodensitométrie. L'intervalle de temps entre la demande de tomodensitométrie et l'imagerie par tomodensitométrie a été calculé et représente l'intervalle « retard au scanner¼. RéSULTATS: L'hôpital d'étude a reçu 8 672 visites aux services d'urgence (SU) et 220 ont été transférés aux centres d'aiguillage (2,5%). 61% de tous les transferts ont fait l'objet d'un scanner. Les transferts pour les urgences sensibles au facteur temps ont pris en moyenne 6 h 52. Les patients ayant subi un accident vasculaire cérébral aigu ont connu un intervalle de temps de 4 h 44. Des conditions moins urgentes et non urgentes ont entraîné un délai encore plus long. CONCLUSIONS: Cette étude met en évidence que l'absence de tomodensitomètre en milieu rural est associée à une augmentation des transferts et à des retards importants. L'amélioration de l'accès aux tomodensitomètres pour les communautés rurales peut être l'une des nombreuses étapes pour remédier aux disparités en matière de soins de santé entre les communautés rurales et urbaines.

Naloxone dosing in the era of ultra-potent opioid overdoses: a systematic review.

OBJECTIVES: Evaluate the relationship between naloxone dose (initial and cumulative) and opioid toxicity reversal and adverse events in undifferentiated and presumed fentanyl/ultra-potent opioid overdoses. METHODS: We searched Embase, MEDLINE, Cochrane Central Register of Controlled Trials, DARE, CINAHL, Science Citation Index, reference lists, toxicology websites, and conference proceedings (1972 to 2018). We included interventional, observational, and case studies/series reporting on naloxone dose and opioid toxicity reversal or adverse events in people >12 years old. RESULTS: A total of 174 studies (110 case reports/series, 57 observational, 7 interventional) with 26,660 subjects (median age 35 years; 74% male). Heterogeneity precluded meta-analysis. Where reported, we abstracted naloxone dose and proportion of patients with toxicity reversal. Among patients with presumed exposure to fentanyl/ultra-potent opioids, 56.9% (617/1,085) responded to an initial naloxone dose ≤0.4 mg compared with 80.2% (170/212) of heroin users, and 30.4% (7/23) responded to an initial naloxone dose >0.4 mg compared with 59.1% (1,434/2,428) of heroin users. Among patients who responded, median cumulative naloxone doses were higher for presumed fentanyl/ultra-potent opioids than heroin overdoses in North America, both before 2015 (fentanyl/ultra-potent opioids: 1.8 mg [interquartile interval {IQI}, 1.0, 4.0]; heroin: 0.8 mg [IQI, 0.4, 0.8]) and after 2015 (fentanyl/ultra-potent opioids: 3.4 mg [IQI, 3.0, 4.1]); heroin: 2 mg [IQI, 1.4, 2.0]). Where adverse events were reported, 11% (490/4,414) of subjects experienced withdrawal. Variable reporting, heterogeneity and poor-quality studies limit conclusions. CONCLUSIONS: Practitioners have used higher initial doses, and in some cases higher cumulative naloxone doses to reverse toxicity due to presumed fentanyl/ultra-potent opioid exposure compared with other opioids. High-quality comparative naloxone dosing studies assessing effectiveness and safety are needed.

Naloxone interventions in opioid overdoses: a systematic review protocol.

BACKGROUND: North America is in the midst of an unabated opioid overdose epidemic due to the increasing non-medical use of fentanyl and ultra-potent opioids. Naloxone is an effective antidote to opioid toxicity, yet its optimal dosing in the context of fentanyl and ultra-potent opioid overdoses remains unknown. This review aims to determine the relationship between the first empiric dose of naloxone and reversal of toxicity, adverse events, and the total cumulative dose required among patients with undifferentiated opioid overdoses and those with suspected toxicity from ultra-potent opioids. Secondary objectives include evaluating the relationship between the cumulative naloxone dose and toxicity reversal and adverse events, among patients with undifferentiated opioid overdoses and those with suspected toxicity from ultra-potent opioids. METHODS: To identify studies, we will search MEDLINE, Embase, CENTRAL, DARE, CDAG, CINAHL, Science Citation Index, multiple trial registries, and the gray literature. Included studies will evaluate patients with suspected or confirmed opioid toxicity from undifferentiated opioids and ultra-potent opioids, who received an empiric and possibly additional doses of naloxone. The main outcomes of interest are the relationship between naloxone dose and toxicity reversal and adverse events. We will include controlled and non-controlled interventional studies, observational studies, case reports/series, and reports from poison control centers. We will extract data and assess study quality in duplicate with discrepancies resolved by consensus or a third party. We will use the Downs and Black and Cochrane risk of bias tools for observational and randomized controlled studies. If we find sufficient variation in dose, we will fit a random effects one-stage model to estimate a dose-response relationship. We will conduct multiple subgroup analyses, including by type of opioid used and by suspected high and low prevalence of ultra-potent opioid use based on geographic location and time of the original studies. DISCUSSION: Our review will include the most up-to-date available data including ultra-potent opioids to inform the current response to the opioid epidemic, addressing the limitations of recent reviews. We anticipate limitations relating to study heterogeneity. We will disseminate study results widely to update overdose treatment guidelines and naloxone dosing in Take Home Naloxone programs.

Acute diesel exhaust exposure and postural stability: a controlled crossover experiment.

Recent epidemiological evidence connects ambient air pollutants to adverse neurobehavioural effects in adults. In animal models, subchronic controlled exposures to diesel exhaust (DE) have also showed evidence of neuroinflammation. Evidence suggests that DE not only affects outcomes commonly associated with cognitive dysfunction, but also balance impairment. We conducted a controlled human exposure experiment with 28 healthy subjects (average age = 28 years (SD = 7.1; range = 21-49); and 40% female) who were exposed to two conditions, filtered air (FA) and DE (300 µg PM2.5/m3) for 120 min, in a double-blinded crossover study with randomized exposures separated by four weeks. Postural stability was assessed by the Balance Error Scoring System (BESS), a brief, easily-administered test of static balance. The BESS consists of a sequence of three stances performed on two surfaces. With hands on hips and eyes closed, each stance is held for 20 s. "Error" points are awarded for deviations from those stances. Pre- and immediately post-exposure BESS "error" point totals were calculated and the difference between the two timepoints were compared for each of the two exposure conditions. A mixed effect model assessed the significance of the association. While our data demonstrates a trend of reduced postural stability in response to exposure to DE, exposure was not significantly associated with BESS value. This is the first study to investigate changes in postural stability as a result of exposure to DE in human subjects.

Effect of diesel exhaust inhalation on blood markers of inflammation and neurotoxicity: a controlled, blinded crossover study.

CONTEXT: Epidemiological studies and animal research have suggested that air pollution may negatively impact the central nervous system (CNS). Controlled human exposure studies of the effect of air pollution on the brain have potential to enhance our understanding of this relationship and to inform potential biological mechanisms. OBJECTIVES: Biomarkers of systemic and CNS inflammation may address whether air pollution exposure induces inflammation, with potential for CNS negative effects. MATERIALS AND METHODS: Twenty-seven healthy adults were exposed to two conditions: filtered air (FA) and diesel exhaust (DE) (300 µg PM2.5/m(3)) for 120 min, in a double-blinded crossover study with exposures separated by four weeks. Prior to and at 0, 3, and 24 h following each exposure, serum and plasma were collected and analyzed for inflammatory cytokines interleukin 6 (IL-6) and tumour necrosis factor alpha (TNF-α), the astrocytic protein S100b, the neuronal cytoplasmic enzyme neuron-specific enolase (NSE), and serum brain-derived neurotrophic factor (BDNF). We hypothesized that IL-6, TNF-α, S100b and NSE would increase, and BDNF would decrease, following DE exposure. RESULTS: At no time-point following exposure to DE was a significant increase in concentration from baseline seen for IL-6, TNF-α, S100b, or NSE relative to FA exposure. Similarly, no significant decrease in BDNF concentration from baseline was seen following DE exposure, relative to FA. Furthermore, the repeated measures ANOVA considered for all time-points and biomarkers revealed no significant time-exposure interaction. DISCUSSION AND CONCLUSION: These results suggest that short-term exposure to DE amongst healthy adults does not acutely affect the systemic or CNS biomarkers that we measured.

A new exposure metric for traffic-related air pollution? An analysis of determinants of hopanes in settled indoor house dust.

BACKGROUND: Exposure to traffic-related air pollution (TRAP) can adversely impact health but epidemiologic studies are limited in their abilities to assess long-term exposures and incorporate variability in indoor pollutant infiltration. METHODS: In order to examine settled house dust levels of hopanes, engine lubricating oil byproducts found in vehicle exhaust, as a novel TRAP exposure measure, dust samples were collected from 171 homes in five Canadian cities and analyzed by gas chromatography-mass spectrometry. To evaluate source contributions, the relative abundance of the highest concentration hopane monomer in house dust was compared to that in outdoor air. Geographic variables related to TRAP emissions and outdoor NO2 concentrations from city-specific TRAP land use regression (LUR) models were calculated at each georeferenced residence location and assessed as predictors of variability in dust hopanes. RESULTS: Hopanes relative abundance in house dust and ambient air were significantly correlated (Pearson's r=0.48, p<0.05), suggesting that dust hopanes likely result from traffic emissions. The proportion of variance in dust hopanes concentrations explained by LUR NO2 was less than 10% in Vancouver, Winnipeg and Toronto while the correlations in Edmonton and Windsor explained 20 to 40% of the variance. Modeling with household factors such as air conditioning and shoe removal along with geographic predictors related to TRAP generally increased the proportion of explained variability (10-80%) in measured indoor hopanes dust levels. CONCLUSIONS: Hopanes can consistently be detected in house dust and may be a useful tracer of TRAP exposure if determinants of their spatiotemporal variability are well-characterized, and when home-specific factors are considered.