Toward mechanistic medical digital twins: some use cases in immunology

A fundamental challenge for personalized medicine is to capture enough of the complexity of an individual patient to determine an optimal way to keep them healthy or restore their health. This will require personalized computational models of sufficient resolution and with enough mechanistic information to provide actionable information to the clinician. Such personalized models are increasingly referred to as medical digital twins. Digital twin technology for health applications is still in its infancy, and extensive research and development is required. This article focuses on several projects in different stages of development that can lead to specific-and practical-medical digital twins or digital twin modeling platforms. It emerged from a two-day forum on problems related to medical digital twins, particularly those involving an immune system component. Open access video recordings of the forum discussions are available.

Forum on immune digital twins: a meeting report

Medical digital twins are computational models of human biology relevant to a given medical condition, which are tailored to an individual patient, thereby predicting the course of disease and individualized treatments, an important goal of personalized medicine. The immune system, which has a central role in many diseases, is highly heterogeneous between individuals, and thus poses a major challenge for this technology. In February 2023, an international group of experts convened for two days to discuss these challenges related to immune digital twins. The group consisted of clinicians, immunologists, biologists, and mathematical modelers, representative of the interdisciplinary nature of medical digital twin development. A video recording of the entire event is available. This paper presents a synopsis of the discussions, brief descriptions of ongoing digital twin projects at different stages of progress. It also proposes a 5-year action plan for further developing this technology. The main recommendations are to identify and pursue a small number of promising use cases, to develop stimulation-specific assays of immune function in a clinical setting, and to develop a database of existing computational immune models, as well as advanced modeling technology and infrastructure.

Pilot investigation of an activity-based approach to building hardiness

BACKGROUND

The purpose was to describe an activity-based psychological hardiness training programme delivered by an occupational therapist and examine its acceptability and effectiveness in improving hardiness.

METHOD

Participants (N=28) completed the 6-hour programme, which included pre/post-programme completion of the Dispositional Resilience Scale-15 (DRS-15) and a Program Evaluation Form. Paired t-tests were used to determine differences between pre-training and post-training scores on the DRS-15.

RESULTS

Results showed a significant increase (p<0.05) in total hardiness, commitment, and control scores on the DRS-15 from pre-training to post-training and good-excellent ratings for all categories on the Program Evaluation Form.

CONCLUSIONS

This programme evaluation described an occupational therapist's role in providing an activity-based psychological hardiness training programme and provided preliminary support for the acceptability of an activity-based approach to training psychological hardiness for service members.

Magnetocardiography as a noninvasive diagnostic strategy for suspected coronary microvascular dysfunction

Background

Coronary microvascular dysfunction (CMD) is increasingly recognized as an independent predictor of mortality with a 4-fold higher risk. However current diagnostic modalities are limited by the need for an invasive procedure, access, cost, and exposure of ionizing radiation.

Purpose

To investigate the ability of magnetocardiography (MCG) to identify CMD in patients with suspected ischemia and no obstructive coronary artery disease (INOCA).

Methods

This is an observational, prospective pilot study of patients scheduled for coronary functional angiography (CFA), gold standard for evaluation for CMD (defined as coronary flow reserve (CFR) ≤2). 13 patients underwent both CFA and a noninvasive 36-channel MCG scan. A machine learning model was developed to characterize the presence of CMD in these patients against age matched controls (AMCs). The model consists of a logistic regression classifier which takes features representing the relative strengths of the “characteristic dipoles” of the MCG scan as input. The characteristic dipoles are parameterizations of the three strongest magnetic field map components resulting from a singular value decomposition of the MCG signal. A total of 37 patients were included in this analysis including 13 patients who completed CFA (7 had CMD and 6 had CFR &gt;2 and included in the AMCs group). An additional 24 asymptomatic, healthy patients that did not undergo CFR were also included in the AMC group.

Results

The mean age for AMCs was 57 years (70% women) and mean age for CMD patients was 54 years (100% women). The performance of the model was evaluated using repeated stratified cross-validation with 5 folds and 3 repeats, resulting in 15 different 80%/20% train/test splits. Figure 1 shows the distribution of samples belonging to the CMD and AMC groups in a 2-dimensional representation of the feature space. The clear separation of the two groups and the clustering of the AMCs demonstrates the ability of the model to identify patients with CMD. We found that MCG had a mean accuracy of 94.8% (±6.4%), sensitivity of 100% (±0.0%) and specificity of 93.3% (±8.2%) for the detection of CMD using gold standard CFR ≤2 as reference.

Conclusion(s)

First study to show that MCG can be used with 94.8% accuracy to identify CMD among patients suspicious for INOCA with no exposure to ionization, 90 seconds of scan time and minimal cost. The use of this noninvasive modality to identify CMD warrants further investigation.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Genetesis

Conformer-specific photochemistry imaged in real space and time

[Figure: see text].

Rapid multi-generational acclimation of coralline algal reproductive structures to ocean acidification

The future of coral reef ecosystems is under threat because vital reef-accreting species such as coralline algae are highly susceptible to ocean acidification. Although ocean acidification is known to reduce coralline algal growth rates, its direct effects on the development of coralline algal reproductive structures (conceptacles) is largely unknown. Furthermore, the long-term, multi-generational response of coralline algae to ocean acidification is extremely understudied. Here, we investigate how mean pH, pH variability and the pH regime experienced in their natural habitat affect coralline algal conceptacle abundance and size across six generations of exposure. We show that second-generation coralline algae exposed to ocean acidification treatments had conceptacle abundances 60% lower than those kept in present-day conditions, suggesting that conceptacle development is initially highly sensitive to ocean acidification. However, this negative effect of ocean acidification on conceptacle abundance disappears after three generations of exposure. Moreover, we show that this transgenerational acclimation of conceptacle development is not facilitated by a trade-off with reduced investment in growth, as higher conceptacle abundances are associated with crusts with faster growth rates. These results indicate that the potential reproductive output of coralline algae may be sustained under future ocean acidification.

Implementing TB preventive treatment within differentiated HIV service delivery models in global programs

Global HIV program stakeholders, including the US President's Emergency Plan for AIDS Relief (PEPFAR), are undertaking efforts to ensure that eligible people living with HIV (PLHIV) receiving antiretroviral treatment (ART) receive a course of TB preventive treatment (TPT). In PEPFAR programming, this effort may require providing TPT not only to newly diagnosed PLHIV as part of HIV care initiation, but also to treatment-experienced PLHIV stable on ART who may not have been previously offered TPT. TPT scale-up is occurring at the same time as a trend to provide more person-centered HIV care through differentiated service delivery (DSD). In DSD, PLHIV stable on ART may receive less frequent clinical follow-up or receive care outside the traditional clinic-based model. The misalignment between traditional delivery of TPT and care delivery in innovative DSD may require adaptations to TPT delivery practices for PLHIV. Adaptations include components of planning and operationalization of TPT in DSD, such as determination of TPT eligibility and TPT initiation, and clinical management of PLHIV while on TPT. A key adaptation is alignment of timing and location for TPT and ART prescribing, monitoring, and dispensing. Conceptual examples of TPT delivery in DSD may help program managers operationalize TPT in HIV care.

0180 Sleep, Sleepiness, and Sleep Hygiene Related to Nomophobia (No Mobile Phone Phobia)

Introduction

Previously, active phone use at bedtime has been implicated in disrupted sleep and related complaints. To improve sleep, a recommendation following such findings is limiting phone use before and during bedtime. However, for those with the characteristic of “nomophobia”, fear of being out of mobile phone contact, this recommendation could exacerbate anxiety at and around bedtime and disrupt, rather than improve, sleep. In 2012, an estimated 77% of 18-24-year-olds could be identified as nomophobic. Because of the prevalence of nomophobia and its possible interaction with sleep, we explored the existence of nomophobia in a college-age population and its relationship to sleep, sleepiness, and sleep hygiene behaviors.

Methods

327 university students (age: M=19.7 years, SD=3.78) recruited from introductory psychology courses and campus newsletters were given extra credit or a chance to win $25 gift cards for participation. Participants completed demographic information, the Nomophobia Questionnaire (NMP-Q), the Epworth Sleepiness Scale (ESS), the Pittsburgh Sleep Quality Index, questions regarding associated features of inadequate sleep hygiene, and the Sleep Hygiene Index. Additional sleep hygiene questions assessed frequency of active and passive technology use during sleep time.

Results

89.4% of the participants had moderate or severe nomophobia. Greater nomophobia was significantly related to greater daytime sleepiness (ESS) (r(293)=.150, p&lt;.05), associated features of poor sleep (daytime sleepiness: r(297)=.097, p&lt;.05, and avolition: r(297)=.100, p&lt;.05), more maladaptive sleep hygiene behaviors including active technology use during sleep time (r(298)=.249, p&lt;.05), long daytime naps, inconsistent wake and bed times, using bed for non-sleep purposes, uncomfortable bed, and bedtime cognitive rumination (r’s=0.097 to 0.182).

Conclusion

Most participants experienced moderate to severe nomophobia with greater nomophobia associated with greater sleepiness, avolition, and poorer sleep hygiene. Nomophobia is likely to be an important consideration when treating sleep disorders and/or making any sleep hygiene recommendations.

Support

Hendrix College Charles Brewer Fund for Psychology

0194 Bedtime Technology Use and New Questions for the Sleep Hygiene Index

Introduction

We examined the relationship between bedtime active and passive social technology use (self and bedpartner) and daytime sleepiness/sleep. We generated questions to differentiate participants with and without bedpartners and updated passive personal, active bedpartner, and passive bedpartner social technology questions of the Sleep Hygiene Index.

Methods

327 students (age: M=19.7 years, SD=3.78) recruited through psychology courses and campus newsletters received extra credit or chances to win $25 gift cards. Participants completed demographic information, the Epworth Sleepiness Scale (ESS), the Pittsburgh Sleep Quality Index, questions regarding associated features of inadequate sleep hygiene, and the Sleep Hygiene Index. Five questions assessed active and passive social technology use, presence of a bedpartner, and awareness of bedpartner active and passive social technology use during sleep time.

Results

61.8% and 62.7% of students reported frequently or always using active and passive bedtime social technology, respectively; and 23.5% and 29.1% reported noticing a partner’s active or passive use. More frequent active technology use was significantly related to greater daytime sleepiness (ESS) (r(305)=.193, p&lt;.05), sleep disturbances (PSQI-global: r(302)=.120, p&lt;.05), and associated features of inadequate sleep hygiene (daytime sleepiness, worry about sleep, mood disturbance, avolition, and reduced cognition (r(306)=.212, p&lt;.05)). Neither passive use nor passive or active partner use was significantly related to any sleep/sleepiness variables.

Conclusion

We continue to find students are frequent users of bedtime social technology which is related to daytime sleepiness, disrupted sleep, and related complaints. Passive and partner active/passive bedtime technology use may not have a significant impact on daytime sleepiness. It is possible younger participants are not good judges of passive or partner technology use or this younger population is resilient to these disruptions.

Support

none

Femtosecond gas-phase mega-electron-volt ultrafast electron diffraction

The development of ultrafast gas electron diffraction with nonrelativistic electrons has enabled the determination of molecular structures with atomic spatial resolution. It has, however, been challenging to break the picosecond temporal resolution barrier and achieve the goal that has long been envisioned-making space- and-time resolved molecular movies of chemical reaction in the gas-phase. Recently, an ultrafast electron diffraction (UED) apparatus using mega-electron-volt (MeV) electrons was developed at the SLAC National Accelerator Laboratory for imaging ultrafast structural dynamics of molecules in the gas phase. The SLAC gas-phase MeV UED has achieved 65 fs root mean square temporal resolution, 0.63 Å spatial resolution, and 0.22 Å-1 reciprocal-space resolution. Such high spatial-temporal resolution has enabled the capturing of real-time molecular movies of fundamental photochemical mechanisms, such as chemical bond breaking, ring opening, and a nuclear wave packet crossing a conical intersection. In this paper, the design that enables the high spatial-temporal resolution of the SLAC gas phase MeV UED is presented. The compact design of the differential pump section of the SLAC gas phase MeV UED realized five orders-of-magnitude vacuum isolation between the electron source and gas sample chamber. The spatial resolution, temporal resolution, and long-term stability of the apparatus are systematically characterized.

A narrative review of the definition of 'flare' in hidradenitis suppurativa

BACKGROUND

Hidradenitis suppurativa (HS) is a chronic, inflammatory condition that can have periodic worsening or flares. Measurement of flare is important because it can inform treatment efficacy; however, it is unclear how HS flare should be defined.

OBJECTIVES

This study reviewed the literature for definitions of HS flare.

METHODS

The PubMed MEDLINE online database was searched on 10 January 2018 and the search was repeated on 8 December 2018 for new publications. Titles and abstracts were screened for inclusion. Subsequently, full articles were screened for inclusion. Papers were included if the publication was a systematic review, clinical trial, cohort study, case report or series, or cross-sectional study. Studies were excluded if they were journalistic reviews, did not discuss clinical findings of HS or did not use the words 'flare', 'exacerbation', 'relapse' or 'recurrence'.

RESULTS

Two hundred and seventy-four papers were identified and 154 fulfilled the study criteria. Of these, 27 (17.5%) included the term 'flare' and 16 (10.4%) included the term 'exacerbation'. Two of the 27 papers (7%) defined the term flare and both included patient report of changes in symptoms or signs. One of 16 papers (6%) defined exacerbation, which was taken as one new HS lesion. The terms 'recurrence' and 'relapse' were more apt to be defined: 13% (13 of 100) and 14% (six of 44), respectively.

CONCLUSIONS

The lack of a specific and measurable definition of HS flare is a barrier to assessment of this important outcome. Once a specific and measurable definition is established, validated and reliable measures of HS flare can be incorporated into future studies. What's already known about this topic? Hidradenitis suppurativa (HS) is a chronic, relapsing inflammatory skin condition. The ability to assess flares is important to people who have HS; however, it is unclear how this is defined. HS flare is one of the core outcomes in the core outcome set for HS clinical trials; however, it is unclear how this should be assessed. What does this study add? This literature review reveals the paucity of measurable definitions associated with the use of the term 'flare' in the HS literature. It also highlights the variation and lack of a validated and reliable measure of HS flare.

Food for thought. Malnutrition risk associated with increased risk of healthcare-associated infection

BACKGROUND

Infection and malnutrition are interconnected. UK and Irish guidelines recommend the Malnutrition Universal Screening Tool (MUST) for nutritional risk screening. Patients with a MUST score of ≥2 are considered at high risk of malnutrition and referral for nutritional assessment is recommended.

AIM

To explore the association between healthcare-associated infection (HCAI) and the MUST score categories of patients.

METHODS

This was a cross-sectional study in May 2017 on ten representative wards in our institution. Patient demographics, MUST score, presence of medical devices, HCAI and antimicrobial use were collected.

FINDINGS

Of 240 patients, the HCAI prevalence was 10.4% (N = 25) and 26% (N = 63) were at high risk of malnutrition (MUST score ≥2). Patients with HCAI were more likely to have had surgery (odds ratio (OR): 5.5; confidence interval (CI): 2.1-14.3; P < 0.001), a central vascular catheter (OR: 10.0; CI: 3.6-27.2; P < 0.001), or a urinary catheter in situ (OR: 7.5; CI: 2.8-20.0; P < 0.001), and to have a high risk of malnutrition (OR: 4.3; CI: 1.7-11.2; P < 0.001). A higher MUST score remained a significant predictor of a patient having HCAI on multivariate regression analysis (CI: 0.2-0.6; P < 0.001).

CONCLUSION

Patients at risk of malnutrition when assessed with the MUST were more likely to have HCAI. However, prospective studies are required to investigate the temporal association between MUST and HCAI and which interventions best address malnutrition risk and HCAI reduction in different settings.

Resistance of corals and coralline algae to ocean acidification: physiological control of calcification under natural pH variability

Ocean acidification is a threat to the continued accretion of coral reefs, though some undergo daily fluctuations in pH exceeding declines predicted by 2100. We test whether exposure to greater pH variability enhances resistance to ocean acidification for the coral Goniopora sp. and coralline alga Hydrolithon reinboldii from two sites: one with low pH variability (less than 0.15 units daily; Shell Island) and a site with high pH variability (up to 1.4 pH units daily; Tallon Island). We grew populations of both species for more than 100 days under a combination of differing pH variability (high/low) and means (ambient pH 8.05/ocean acidification pH 7.65). Calcification rates of Goniopora sp. were unaffected by the examined variables. Calcification rates of H. reinboldii were significantly faster in Tallon than in Shell Island individuals, and Tallon Island individuals calcified faster in the high variability pH 8.05 treatment compared with all others. Geochemical proxies for carbonate chemistry within the calcifying fluid (cf) of both species indicated that only mean seawater pH influenced pH_cf pH treatments had no effect on proxies for Ω_cf These limited responses to extreme pH treatments demonstrate that some calcifying taxa may be capable of maintaining constant rates of calcification under ocean acidification by actively modifying Ω_cf.

Mentoring for newly appointed consultant psychiatrists

The south-west Mentoring Scheme has developed in the context of a general and increasing concern for the health and morale of senior doctors (British Medical Association (BMA), 2000). Their problems are now well described (Allen, 1999; Ghodseet al, 2000), but there is little evidence of effective intervention. The aspirations of the National Service Framework and the NHS Plan will come to nothing if there are not sufficient trained and experienced staff to implement them, and senior staff are increasingly looking forward to early retirement rather than the continued satisfactions of working within the NHS. Recruitment and retention of consultant psychiatrists is the most problematic of all medical specialities, with 14% of posts empty or occupied by locums (Sainsbury Centre for Mental Health, 2000). There is a clear need to find ways of preventing work-related ill health, stress and burn-out among practitioners (Roberts, 1997; Department of Health, 1999: p 115), and to sustain their creative and productive engagement in health care. A demotivated profession cannot be expected to deliver an effective service (McBride & Metcalf, 1995; Appletonet al, 1998) and policy is not a substitute for personnel.

Abstract 235: Interaction Between a Macrophage Chemokine Receptor, CCR2, and Its Ligand Plays a Crucial Role in Macrophage Recruitment Aand Regulated Inflammation in Normal Wound Healing

Background: Wound healing in chronic diseases, such as type 2 diabetes (T2D), is impaired due to dysregulated inflammation. Innate immune cells, particularly macrophages, play a significant role in regulated inflammation following tissue injury. After injury, CCR2+ monocytes are recruited to the peripheral wound. This recruitment is mediated in part by the CCR2 ligand, CCL2. Thus, we hypothesized that the CCL2/CCR2 interaction is vital for normal wound healing and appropriate inflammation, and that this signaling cascade is impaired in T2D.

Methods: CCR2 -/- mice and littermate controls underwent 4mm hindlimb wounds, and wound closure was compared daily. Wound macrophages (CD3-CD19-NK1.1-CD11b+ cells) were analyzed on day 3 by flow cytometry for intracellular cytokine production. Adoptive transfer was performed using blood CD11b+ cells from WT C57BL/6 or CCR2 -/- mice isolated by magnetic sorting and transferred into CCR2 -/- mice via tail vein injection. Mice were then wounded and wound closure was compared between the two groups. C57BL/6 mice were maintained on normal or high fat diet for 12-14 weeks, wounds were created, and CD11b+ cells were isolated from wounds on day 2. ELISA for CCL2 was performed.

Results: CCR2 -/- mice showed significantly impaired wound healing on days 2-7 compared with littermate controls. Macrophages isolated on day 3 from wounds of CCR2 -/- mice expressed significantly less inflammatory cytokines (IL-1β, TNF-α) by qPCR. Flow cytometry analysis revealed less Ly6C hi macrophages in the wounds, as well as macrophages that made significantly less IL-1β, NOS2, and TNF-α. When adoptive transfer was performed, wound healing was restored to normal in the mice that received WT compared to those that received CCR2 -/- CD11b+ cells (P< 0.01). Since CCR2 is important for normal wound inflammation, and we have previously shown that inflammation is impaired in the diet-induced obese (DIO) mice, we examined CCL2 in DIO wounds. CCL2 was significantly decreased in DIO wound macrophages on day 2.

Conclusion: Appropriate CCR2/CCL2 interaction plays a crucial role in macrophage recruitment and regulated inflammation in normal wound healing. Impairment in CCR2/CCL2 signaling may be responsible, in part, for delayed early inflammation in T2D.

Development and evaluation of an online educational resource about cancer survivorship for cancer nurses: a mixed-methods sequential study

Cancer survivorship is recognised globally as a key issue. In spite of the key role played by nurses in survivorship care, there is an identified gap in nurse's knowledge in this area. This study reports on the development and evaluation of an educational resource for nurses working with people affected by cancer. The resource was designed using adult learning principles and includes a variety of learning materials and point of care resources. A mixed-methods sequential exploratory design was used to undertake an evaluation of the programme. This included the use of online surveys and semi-structured interviews with pilot participants. A total of 21 participants completed an online survey and 11 participants completed a telephone interview. Overall, the participants found the Cancer Survivorship resource to be engaging, practical and intuitive. A major theme emerging from the survey and interview data was that the resource was applicable to practice and useful in developing survivorship care plans. Respondents requested additional information be included on the role of various health professionals working in survivorship as well as guidelines on when to make referrals. This study provides evidence that the Cancer Survivorship tool may be a promising vehicle for delivering evidence-based education on survivorship care.

The eye of the Barbary sheep or aoudad (Ammotragus lervia): reference values for selected ophthalmic diagnostic tests, morphologic and biometric observations

The purpose of this study was to describe the normal ocular anatomy and establish reference values for ophthalmic tests in the Barbary sheep or aoudad (Ammotragus lervia). Aoudad eyes are large and laterally positioned in the head with several specialized anatomic features attributed to evolutionary adaptations for grazing. Normal values for commonly used ophthalmic tests were established, Schirmer tear test (STT) - 27.22 ± 3.6 mm/min; Predominant ocular surface bacterial microbiota - Staphylococcus sp.; Corneal esthesiometry- 1.3 ± 0.4 cm; Intraocular pressure by rebound tonometry- 19.47 ± 3.9 mmHg; Corneal thickness- 630.07 ± 20.67 µm, B-mode ultrasonography of the globe-axial eye globe length 29.94 ± 0.96 mm, anterior chamber depth 5.03 ± 0.17 mm, lens thickness 9.4 ± 0.33 mm, vitreous chamber depth 14.1 ± 0.53 mm; Corneal diameter-horizontal corneal diameter 25.05 ± 2.18 mm, vertical corneal diameter 17.95 ± 1.68 mm; Horizontal palpebral fissure length- 34.8 ± 3.12 mm. Knowledge of these normal anatomic variations, biometric findings and normal parameters for ocular diagnostic tests may assist veterinary ophthalmologists in the diagnosis of ocular diseases in this and other similar species.

Investigating a Novel Measure of Brain Networking Following Sports Concussion

Clinicians managing sports-related concussions are left to their clinical judgment in making diagnoses and return-to-play decisions. This study was designed to evaluate the utility of a novel measure of functional brain networking for concussion management. 24 athletes with acutely diagnosed concussion and 21 control participants were evaluated in a research laboratory. At each of the 4 post-injury time points, participants completed the Axon assessment of neurocognitive function, a self-report symptom inventory, and the auditory oddball and go/no-go tasks while electroencephalogram (EEG) readings were recorded. Brain Network Activation (BNA) scores were calculated from EEG data related to the auditory oddball and go/no-go tasks. BNA scores were unable to differentiate between the concussed and control groups or by self-report symptom severity. These findings conflict with previous work implementing electrophysiological assessments in concussed athletes, suggesting that BNA requires additional investigation and refinement before clinical implementation.

Northward expansion of paddy rice in northeastern Asia during 2000-2014

Paddy rice in monsoon Asia plays an important role in global food security and climate change. Here we documented annual dynamics of paddy rice areas in the northern frontier of Asia, including Northeastern (NE) China, North Korea, South Korea, and Japan, from 2000-2014 through analysis of satellite images. The paddy rice area has increased by 120% (2.5 to 5.5 million ha) in NE China, in comparison to a decrease in South Korea and Japan, and the paddy rice centroid shifted northward from 41.16 °N to 43.70 °N (~310 km) in this period. Market, technology, policy, and climate together drove the rice expansion in NE China. The increased use of greenhouse nurseries, improved rice cultivars, agricultural subsidy policy, and a rising rice price generally promoted northward paddy rice expansion. The potential effects of large rice expansion on climate change and ecological services should be paid more attention in the future.

Association between marijuana use and adverse obstetrical and neonatal outcomes

OBJECTIVE

To evaluate associations between marijuana exposure and adverse outcomes excluding women with polysubstance abuse and stratifying for concurrent maternal tobacco use.

STUDY DESIGN

We performed a retrospective cohort study evaluating various obstetrical and neonatal outcomes including: preterm delivery, pre-eclampsia, gestational diabetes, cesarean delivery, fetal growth restriction, a composite which included stillbirth or neonatal intensive care unit admission, and perinatal mortality. We stratified study groups according to the maternal tobacco use and performed a logistic regression analysis.

RESULTS

We included 6468 women, 6107 nonusers and 361 marijuana users. After adjustment for maternal age, race, parity, body mass index and no prenatal care, we found higher rates of small for gestational age (aOR 1.30 (95% CI 1.03 to 1.62)) and neonatal intensive care unit admission (aOR 1.54 (1.14 to 2.07)) in women who were not tobacco users. Other obstetrical outcomes including preterm delivery and fetal anomalies were not increased with maternal marijuana use.

CONCLUSION

Maternal marijuana use does not increase the risk of adverse obstetrical outcomes or fetal anomalies, but does increase the risk for small for gestational age and neonatal intensive care unit admission.

Paramedic rapid sequence intubation in patients with non-traumatic coma

INTRODUCTION

Pre-hospital intubation by paramedics is widely used in comatose patients prior to transportation to hospital, but the optimal technique for intubation is uncertain. One approach is paramedic rapid sequence intubation (RSI), which may improve outcomes in adult patients with traumatic brain injury. However, many patients present to emergency medical services with coma of non-traumatic cause and the role of paramedic RSI in these patients remains uncertain.

METHODS

The electronic Victorian Ambulance Clinical Information System was searched for the term 'suxamethonium' between 2008 and 2011. We reviewed the patient care records and included patients with suspected non-traumatic coma who were treated and transported by road-based paramedics. Demographics, intubation conditions, vital signs (before and after drug administration) and complications were recorded. Younger patients (<60 years) were compared with older patients.

RESULTS

There were 1152 paramedic RSI attempts of which 551 were for non-traumatic coma. The success rate for intubation was 97.5%. There was a significant drop in blood pressure in younger patients (<60 years) with the mean systolic blood pressure decreasing by 16 mm Hg (95% CI 11 to 21). In older patients, the systolic blood pressure also decreased significantly by 20 mm Hg (95% CI 17 to 24). Four patients suffered brief cardiac arrest during pre-hospital care, all of whom were successfully resuscitated and transported to hospital.

CONCLUSIONS

Paramedic RSI in patients with non-traumatic coma has a high procedural success rate. Further studies are required to determine whether this procedure improves outcomes.