Trajectory classes of engagement with an alcohol text message intervention and predictors of intervention engagement

Digital interventions have increased our capacity to reach young adults who have hazardous alcohol use. Alcohol text message interventions have shown small effects in reducing hazardous drinking, leaving room for improvement. An important challenge to address in improving digital interventions is maintaining engagement, which reflects the "dose" of intervention received. This study aimed to identify trajectory classes of engagement with an alcohol text message intervention, and baseline predictors of the trajectory classes to determine "for whom" the digital intervention was more versus less engaging, to guide further intervention tailoring. This secondary analysis examined data from a study that compared five 12-week alcohol text message interventions designed to reduce hazardous drinking in young adults (aged 18-25; N = 1,131, 68% female) recruited from Emergency Departments in Western Pennsylvania. Engagement with the intervention was based on response (present/absent) to text message queries delivered twice per week during 2-week run-in and 12-week intervention. Repeated measures latent profile analysis identified five latent trajectory classes as having the best fit to the data: "High engagement" (55.1%), "Slow decrease, moderate engagement" (23.2%); "Mid-way decrease in engagement" (8.9%), "Steadily decreasing engagement" (8.1%); and "Fluctuating, moderate engagement" (4.6%). Females and individuals enrolled in college were overrepresented in the high engagement trajectory class, whereas individuals higher in impulsivity were more likely to be in decreasing (versus high) engagement trajectory classes. Methods to boost engagement using, for example, motivational enhancement for young adults with higher levels of impulsivity, at specific time points, such as the mid-point of the intervention, warrant consideration.

A longitudinal assessment of posttraumatic stress symptoms and pain catastrophizing after injury

PURPOSE/OBJECTIVE

Identifying individuals with high levels of pain catastrophizing (PC) may inform early psychological interventions to prevent the transition from acute to chronic post-injury pain. We examined whether pre-and post-injury posttraumatic stress symptoms (PTSS) predict post-injury PC among emergency department (ED) patients following acute motor vehicle crash (MVC).

RESEARCH METHOD/DESIGN

This study represents secondary data analysis of a randomized clinical trial (NCT03247179) examining the efficacy of the PTSD Coach app on post-injury PTSS (PTSSpost). Among 63 injured ED patients (63% female; 57% non-White; average age = 37) with moderate pain (≥4 of 10), we assessed recall of pre-injury PTSS (PTSSrecall: stemming from preexisting exposures) and baseline PC within 24 hr post-MVC; PTSSpost stemming from the MVC was assessed 30-days later, and the outcome of PC was assessed at 90-days post-injury. We controlled for group assignment (intervention vs. control) in all analyses.

RESULTS

Results revealed that at baseline and 90-days, PC was higher among non-White versus White participants. After adjusting for relevant covariates, PTSSrecall uniquely predicted post-injury PC and each subscale of PC (helplessness, magnification, and rumination). Similarly, after controlling for PTSSrecall and relevant covariates, PTSSpost uniquely predicted total and subscale post-injury PC. Intervention group participants reported less rumination than control group participants.

CONCLUSIONS/IMPLICATIONS

These novel findings highlight that injured Black patients may be vulnerable to post-injury PC, and that both PTSSrecall and PTSSpost significantly predict post-injury PC. Brief PTSS assessment in the ED can identify high-risk patients who may benefit from early intervention. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Examining the prevalence and health impairment associated with subthreshold PTSD symptoms (PTSS) among frontline healthcare workers during the COVID-19 pandemic

The COVID-19 pandemic has increased healthcare workers' (HCWs) risk for posttraumatic stress disorder (PTSD). Although subthreshold PTSD symptoms (PTSS) are common and increase vulnerability for health impairments, they have received little attention. We examined the prevalence of subthreshold PTSS and their relationship to physical health symptoms and sleep problems among HCWs during the pandemic's second wave (01/21-02/21). Participants (N = 852; 63.1% male; M_age = 38.34) completed the Short-Form PTSD Checklist (SF-PCL), the Cohen-Hoberman Inventory of Physical Symptoms, and the PROMIS Sleep-Related Impairment-Short-Form 4a. We created three groups with the SF-PCL: scores ≥11 = probable PTSD (5.5%); scores between 1 and 10 = subthreshold PTSS (55.3%); scores of 0 = no PTSS (39.2%). After controlling for demographics, occupational characteristics, and COVID-19 status, HCWs with subthreshold PTSS experienced greater physical health symptoms and sleep problems than HCWs with no PTSS. While HCWs with PTSD reported the greatest health impairment, HCWs with subthreshold PTSS reported 88% more physical health symptoms and 36% more sleep problems than HCWs with no PTSS. Subthreshold PTSS are common and increase risk for health impairment. Interventions addressing HCWs' mental health in response to the COVID-19 pandemic must include subthreshold PTSS to ensure their effectiveness.

The role of specific sources of social support on postinjury psychological symptoms

PURPOSE/OBJECTIVE

The role of perceived social support from specific sources (e.g., families, friends, and significant others) on the development of postinjury posttraumatic stress disorder (PTSD) and associated psychological symptoms (e.g., depression and anxiety) remains relatively unexplored. We examined the predictive role of social support from specific sources on psychological symptoms among emergency department (ED) patients following motor vehicle crash (MVC). Research Methods/Design: Sixty-three injured patients (63.5% female; 37 years old on average) with moderately painful complaints were recruited in the EDs of two Level-1 trauma centers within 24 hr post-MVC. In the ED, participants completed surveys of baseline psychological symptoms and perceived social support; follow-up surveys were completed at 90 days postinjury.

RESULTS

Most of the sample (84.1%) was discharged home from the ED with predominantly mild injuries and did not require hospitalization. After adjusting for race, sex, age, and baseline symptoms, hierarchical regression analyses demonstrated that lower perceived social support in the ED predicted higher PTSD symptoms and depressive symptoms (but not anxiety) at 90 days. This effect seemed to be specific to significant others and friends but not family.

CONCLUSIONS/IMPLICATIONS

MVC-related injuries are robust contributors to psychological sequelae. These findings extend prior work by highlighting that perceived social support, particularly from significant others and friends, provides unique information regarding the development of psychological symptoms following predominantly mild MVC-related injuries. This data may serve to inform recovery expectations. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

COVID-19 Vaccine Uptake and Intent Among Emergency Healthcare Workers: A Cross-Sectional Survey

OBJECTIVE

Vaccine hesitancy limits population protection from SARS-CoV (coronavirus disease [COVID-19]). Vaccine hesitancy among healthcare workers (HCW) could put patients and coworkers at risk.

METHODS

We surveyed 475 emergency department and emergency medical service workers from January to February 2021 to determine vaccine intent/uptake, perceived COVID-19 vulnerability, and factors associated with vaccine intent/uptake.

RESULTS

Although 79% of HCWs received or had plans to receive the COVID-19 vaccine, 21% had no intent/were unvaccinated; intent/uptake was lower among females (odds ratio [OR] = 0.34) and those with a history of COVID-19 infection (OR = 0.55), and higher among those with advanced degrees (OR = 3.53) and high perceived COVID-19 vulnerability (OR = 1.99).

CONCLUSIONS

This study provides a timely assessment of vaccination status among frontline HCWs and highlights subgroups who may be at high risk of exposure and transmission.

Abstract P121: Automated Messaging Program To Facilitate Systematic Home Blood Pressure Monitoring: A Qualitative Analysis Of Provider Interviews

Introduction: Hypertension is a leading cause of morbidity worldwide. Home blood pressure monitoring (HBPM) has been shown to lower blood pressure (BP) if paired with co-interventions but such programs are not routinely used in clinical care. MyBP is an automated bi-directional text messaging HBPM program that assists lowering of BP, but how to best implement within clinical care remains unknown. Therefore, in this study, we sought stakeholder input from care providers.

Methods: We conducted semi-structured interviews (average recorded duration 28 minutes) with physicians, nurses, and medical assistants from primary care settings, most of whom had participated in a feasibility trial of MyBP. The interview was designed around constructs from the Consolidated Framework for Implementation Research. Interviews were transcribed verbatim and analyzed using inductive coding to organize meaningful excerpts and identify salient themes.

Results: Subjects were physicians (n = 11) and nurses/medical assistants (n = 6). Care providers felt that patients benefitted from MyBP’s positive influence on BP measurement adherence, psychological factors (such as health literacy and patient empowerment), and perceived patient usability of the program. They reported that the program data aided in clinical diagnosis and management of HTN with a practical user interface for providers. Barriers to implementation included lack of integration into the electronic medical record and difficulty in training office staff in its use.

Conclusion: In this qualitative analysis of care provider stakeholders, MyBP was seen as a pragmatic and effective way to empower patients in BP self-management and tangibly aid providers. Future research will need to focus on strategies to overcome implementation barriers to facilitate integration in to the clinical and digital environment.

A Pilot Randomized Controlled Trial of the PTSD Coach App Following Motor Vehicle Crash-related Injury

OBJECTIVE

Posttraumatic stress disorder (PTSD) symptoms (PTSS) are common after minor injuries and can impair recovery. We sought to understand whether an evidence-based mobile phone application with self-help tools (PTSD Coach) could be useful to improve recovery after acute trauma among injured emergency department (ED) patients. This pilot study examined the feasibility, acceptability, and potential benefit of using PTSD Coach among acutely injured motor vehicle crash (MVC) patients.

METHODS

From September 2017 to September 2018, we recruited adult patients within 24 hours post-MVC from the EDs of two Level I trauma centers in the United States. We randomly assigned 64 injured adults to either the PTSD Coach (n = 33) or treatment as usual (TAU; n = 31) condition. We assessed PTSS and associated symptoms at 1 month (83% retained) and 3 months (73% retained) postenrollment.

RESULTS

Enrollment was feasible (74% of eligible subjects participated) but usability and engagement were low (67% used PTSD Coach at least once, primarily in week 1); 76% of those who used it rated the app as moderately to extremely helpful. No differences emerged between groups in PTSS outcomes. Exploratory analyses among black subjects (n = 21) indicated that those in the PTSD Coach condition (vs. TAU) reported marginally lower PTSS (95% CI = -0.30 to 37.77) and higher PTSS coping self-efficacy (95% CI = -58.20 to -3.61) at 3 months.

CONCLUSIONS

We demonstrated feasibility to recruit acutely injured ED patients into an app-based intervention study, yet mixed evidence emerged for the usability and benefit of PTSD Coach. Most patients used the app once and rated it favorably in regard to satisfaction with and helpfulness, but longitudinal engagement was low. This latter finding may explain the lack of overall effects on PTSS. Additional research is warranted regarding whether targeting more symptomatic patients and the addition of engagement and support features can improve efficacy.

SMS-facilitated home blood pressure monitoring: A qualitative analysis of resultant health behavior change

OBJECTIVE

Hypertension is largely asymptomatic and, as a result, patients often fail to sufficiently engage in medication adherence and other health behaviors to control their blood pressure (BP). This study explores the mechanisms by which MyBP, an automated SMS-facilitated home blood pressure monitoring (HBPM) program, helps facilitate healthy behavior changes.

METHODS

A thematic analysis of transcribed audio-recordings from semi-structured post-intervention interviews (n = 40) was conducted.

RESULTS

Three primary themes were identified as contributing most to patients' decision to initiate a behavior change: 1) increased hypertension literacy attributed to educational videos presented at enrollment, 2) increased day-to-day salience of blood pressure levels as a result of consistent HBPM, and 3) use of BP readings as feedback, with high readings triggering motivations to make behavior changes. These themes and most accompanying sub-themes correspond to constructs in the Health Belief Model and Social Cognitive Theory.

CONCLUSION

Patient-centered HBPM interventions such asMyBP appear to promote improvements in hypertension self-management via several mechanisms consistent with recognized models of behavior change.

PRACTICE IMPLICATIONS

SMS-supported HBPM, paired with video-based education, may provide a simple and scalable way of encouraging health behavior adherence in hypertensive patients.

Development and Preliminary Feasibility of an Automated Hypertension Self-Management System

BACKGROUND

Uncontrolled hypertension constitutes a significant challenge throughout the world. Blood pressure measurement by patients is informative for both patients and providers but is rarely performed systematically, thereby reducing its utility. Mobile phones can be used to efficiently prompt individuals to measure blood pressure and automate data management while avoiding technology barriers to widespread adoption. Presented is the design and pilot test results of MyBP, an automated texting intervention to support blood pressure self-monitoring and patient self-management.

METHODS

Three sequential phases are described: (1) stakeholders' needs assessment, (2) preliminary design pilot (n = 10), and (3) a 6-week pilot of the redesigned comprehensive program with hypertensive patients (n = 43) recruited from 3 clinical sites (Emergency Department, Primary Care, Hypertension Center). Outcomes of interest included participant adherence, perceived importance of blood pressure monitoring, and healthy behavior change.

RESULTS

Median adherence to MyBP prompts over 6 weeks was 79% (72% emergency department, 84% primary care, and 96% hypertension center, H[2] = 5.56, P = .06). Adherence did not vary by age, sex, education, or baseline use of texting but was lowest among patients recruited from the emergency department (χ[2]2 = 6.66, P = .04). In the exit survey, MyBP was associated with increased importance of blood pressure self-monitoring and particularly motivated primary care and emergency department groups to improve dietary habits, increase daily physical activity, and focus on stress reduction. The majority of participants (88%) indicated interest in using the program for 6 months.

CONCLUSIONS

Automated mobile-phone-based blood pressure self-monitoring using MyBP is feasible, acceptable, and scalable, and may improve self-management and support clinical care.

Feasibility and Acceptability of a Motivational Intervention Combined with Text Messaging for Alcohol and Sex Risk Reduction with Emergency Department Patients: A Pilot Trial

BACKGROUND

Interventions aimed at reducing co-occurring heavy drinking and risky sexual behavior among Emergency Department (ED) patients require feasibility and acceptability to optimally engage individuals.

OBJECTIVES

This pilot study explored the feasibility and acceptability of an interactive text-messaging (TM) supplement to a brief in-person intervention previously found successful in reducing alcohol use and condomless sex.

METHODS

Using a mixed-method design, ED patients with past hazardous alcohol use and condomless sex (N= 20) were randomly assigned to receive either a Motivational Intervention + TM or Brief Advice + TM. All participants completed exit interviews at four weeks follow-up, and transcripts were transcribed and coded to identify themes. We evaluated feasibility through quantitative assessment of TM response rates and latency to response, while acceptability was evaluated through thematic analysis of exit interviews.

RESULTS

Findings provide support for the delivery of an integrated and personalized MI and TM. Participants engaged positively with the TM intervention and qualitative interviews offered strong support for the acceptability while offering information necessary to enhance the TM component.

CONCLUSIONS

Integrating MI with TM is feasible and acceptable to at-risk ED patients and could facilitate behavior changes beyond MI alone.

Quantitative sensory testing measures individual pain responses in emergency department patients

Background

Refining and individualizing treatment of acute pain in the emergency department (ED) is a high priority, given that painful complaints are the most common reasons for ED visits. Few tools exist to objectively measure pain perception in the ED setting. We speculated that variation in perception of fixed painful stimuli would explain individual variation in reported pain and response to treatment among ED patients.

Materials and methods

In three studies, we 1) describe performance characteristics of brief quantitative sensory testing (QST) in 50 healthy volunteers, 2) test effects of 10 mg oxycodone versus placebo on QST measures in 18 healthy volunteers, and 3) measure interindividual differences in nociception and treatment responses in 198 ED patients with a painful complaint during ED treatment. QST measures adapted for use in the ED included pressure sensation threshold, pressure pain threshold (PPT), pressure pain response (PPR), and cold pain tolerance (CPT) tests.

Results

First, all QST measures had high inter-rater reliability and test–retest reproducibility. Second, 10 mg oxycodone reduced PPR, increased PPT, and prolonged CPT. Third, baseline PPT and PPR revealed hyperalgesia in 31 (16%) ED subjects relative to healthy volunteers. In 173 (88%) ED subjects who completed repeat testing 30 minutes after pain treatment, PPT increased and PPR decreased (Cohen’s d_z 0.10–0.19). Verbal pain scores (0–10) for the ED complaint decreased by 2.2 (95% confidence intervals [CI]: 1.9, 2.6) (Cohen’s d_z 0.97) but did not covary with the changes in PPT and PPR (r=0.05–0.13). Treatment effects were greatest in ED subjects with a history of treatment for anxiety or depression (Cohen’s d_z 0.26–0.43) or with baseline hyperalgesia (Cohen’s d_z 0.40–0.88).

Conclusion

QST reveals individual differences in perception of fixed painful stimuli in ED patients, including hyperalgesia. Subgroups of ED patients with hyperalgesia and psychiatric history report larger treatment effects on ED pain and QST measures.

Real-time fatigue reduction in emergency care clinicians: The SleepTrackTXT randomized trial

BACKGROUND

We assessed performance characteristics and impact of a mobile phone text-message intervention for reducing intra-shift fatigue among emergency clinician shift workers.

METHODS

We used a randomized controlled trial of 100 participants. All participants received text-message assessments at the start, every 4 hr during, and at end of scheduled shifts over a 90-day period. Text-message queries measured self-rated sleepiness, fatigue, and difficulty with concentration. Additional text-messages were sent to intervention participants to promote alertness. A performance measure of interest was compliance with answering text-messages.

RESULTS

Ninety-nine participants documented 2,621 shifts and responded to 36,073 of 40,947 text-messages (88% compliance rate). Intervention participants reported lower mean fatigue and sleepiness at 4 hr, 8 hr, and at the end of 12 hr shifts compared to controls (P < 0.05). Intervention participants reported better sleep quality at 90-days compared to baseline (P = 0.01).

CONCLUSIONS

We showed feasibility and short-term efficacy of a text-message based assessment and intervention tool.

Emergency healthcare worker sleep, fatigue, and alertness behavior survey (SFAB): development and content validation of a survey tool

BACKGROUND

Workplace safety is a recognized concern in emergency medical services (EMS). Ambulance crashes are common and injury rates exceed that of the general working public. Fatigue and sleepiness during shift work pose a safety risk for patients and EMS workers. Changing EMS worker behaviors and improving alertness during shift work is hampered by a lack of instruments that reliably and accurately measure multidimensional beliefs and habits that predict alertness behavior.

OBJECTIVES

We sought to test the reliability and validity of a survey tool (the sleep, fatigue, and alertness behavior survey [SFAB]) designed to identify the cognitions of EMS workers concerning sleep, fatigue, and alertness behaviors during shift work.

METHODS

We operationalized the integrative model of behavioral prediction (IMBP) and developed a pool of 97 candidate items and sub-items to measure eight domains of the IMBP. Five sleep scientists judged the content validity of each item and a convenience sample of EMS workers completed a paper-based version of the SFAB. We retained items judged content valid by five sleep scientists and performed exploratory factor analysis (EFA), confirmatory factor analysis (CFA), and tests of reliability and internal consistency. We identified a simple factor structure for each scale and calculated means and standard deviations for each item and scale.

RESULTS

We received 360 completed SFAB surveys from a convenience sample of 800 EMS workers attending two regional continuing education conferences (45% participation rate). Forty-seven candidate items and sub-items/options were removed following content validation, EFA, and CFA testing. Analyses revealed a simple factor structure for seven of eight domains and a final pool of 50 items and sub-items/options. Domains include: attitudes, normative beliefs, knowledge, salience, habits, environmental constraints, and intent. EFA tests of self-efficacy items failed to identify a simple factor structure. We retained two self-efficacy items based on Spearman-Brown correlation of 0.23 (p<0.0001).

CONCLUSIONS

Measurement of sleep, fatigue, and alertness behavior among EMS workers is challenging. We describe the development and psychometric testing of a survey tool that may be useful in a variety of applications addressing sleep, fatigue, and alertness behavior among EMS workers.

Chest compressions do not disrupt the seal created by the laryngeal mask airway during positive pressure ventilation: a preliminary porcine study

OBJECTIVE

Pulmonary aspiration of gastric contents occurs 20 to 30% of the time during cardiopulmonary resuscitation (CPR) of cardiac arrest due to loss of protective airway reflexes, pressure changes generated during CPR, and positive pressure ventilation (PPV). Although the American Heart Association has recommended the laryngeal mask airway (LMA) as an acceptable alternative airway for use by emergency medical service personnel, concerns over the capacity of the device to protect from pulmonary aspiration remain. We sought to determine the occurrence of aspiration after LMA placement, CPR, and PPV.

METHODS

We inserted a size 4 LMA, modified so that a vacuum catheter could be advanced past the LMA diaphragm, into the hypopharynx of 16 consecutive postexperimental mixed-breed domestic swine. Fifteen millilitres of heparinized blood was instilled into the oropharynx. Chest compressions were performed for 60 seconds with asynchronous ventilation via a mechanical ventilator. We then suctioned through the LMA for 1 minute. The catheter was removed and inspected for signs of blood. The LMA cuff was deflated, removed, and inspected for signs of blood.

RESULTS

None of 16 animals (95% CI 0-17%) had a positive test for the presence of blood in both the vacuum catheter and the intima of the LMA diaphragm.

CONCLUSIONS

In this swine model of regurgitation after LMA placement, there were no cases with evidence of blood beyond the seal created by the LMA cuff. Future studies are needed to determine the frequency of pulmonary aspiration after LMA placement during CPR and PPV in the clinical setting.

Mobile phone text messaging intervention to improve alertness and reduce sleepiness and fatigue during shiftwork among emergency medicine clinicians: study protocol for the SleepTrackTXT pilot randomized controlled trial

Background

Mental and physical fatigue while at work is common among emergency medical services (EMS) shift workers. Extended shifts (for example 24 hours) and excessive amounts of overtime work increase the likelihood of negative safety outcomes and pose a challenge for EMS fatigue-risk management. Text message-based interventions are a potentially high-impact, low-cost platform for sleep and fatigue assessment and distributing information to workers at risk of negative safety outcomes related to sleep behaviors and fatigue.

Methods/Design

We will conduct a pilot randomized trial with a convenience sample of adult EMS workers recruited from across the United States using a single study website. Participants will be allocated to one of two possible arms for a 90-day study period. The intervention arm will involve text message assessments of sleepiness, fatigue, and difficulty with concentration at the beginning, during, and end of scheduled shifts. Intervention subjects reporting high levels of sleepiness or fatigue will receive one of four randomly selected intervention messages promoting behavior change during shiftwork. Control subjects will receive assessment only text messages. We aim to determine the performance characteristics of a text messaging tool for the delivery of a sleep and fatigue intervention. We seek to determine if a text messaging program with tailored intervention messages is effective at reducing perceived sleepiness and/or fatigue among emergency medicine clinician shift workers. Additional aims include testing whether a theory-based behavioral intervention, delivered by text message, changes ‘alertness behaviors’.

Discussion

The SleepTrackTXT pilot trial could provide evidence of compliance and effectiveness that would support rapid widespread expansion in one of two forms: 1) a stand-alone program in the form of a tailored/individualized sleep monitoring and fatigue reduction support service for EMS workers; or 2) an add-on to a multi-component fatigue risk management program led and maintained by employers or by safety and risk management services.

Trial Registration

Clinicaltrials.gov NCT02063737, Registered on 10 January 2014

Pre-resuscitation lactate and hospital mortality in prehospital patients

OBJECTIVE

Serum lactate elevations are associated with morbidity and mortality in trauma patients, but their value in prehospital medical patients prior to resuscitation is unknown. We sought to assess the distribution of blood lactate concentrations prior to intravenous (i.v.) resuscitation and examine the association of elevation on in-hospital death.

METHODS

A convenience sample of adult patients over 14 months who received an i.v. line by eight EMS agencies in Western Pennsylvania had lactate measurement prior to any i.v. treatment. We assessed the lactate values and any relationship between these and hospital mortality (our primary outcome) and admission to the intensive care unit (ICU). We also compared the ability of lactate to discriminate outcomes with a prehospital critical illness score using age, Glasgow Coma Score, and initial vital signs.

RESULTS

We included 673 patients, among whom 71 (11%) were admitted to the ICU and 21 (3.1%) died in-hospital. Elevated lactate (≥2 mmol/L) occurred in 307 (46%) patients and was strongly associated with hospital death after adjustment for known covariates (odds ratio = 3.57, 95% confidence interval [CI]: 1.10, 11.6). Lactate ≥2 mmol/L had a modest sensitivity (76%) and specificity (55%), and discrimination for hospital death (area under the curve [AUC] = 0.66, 95%CI: 0.56, 0.75). Compared to the prehospital critical illness score alone (AUC = 0.69, 95% CI: 0.59, 0.80), adding lactate to the score offered modest improvement (net reclassification improvement = 0.63, 95%CI: 0.23, 1.01, p < 0.05).

CONCLUSIONS

Initial lactate concentration in our prehospital medical patient population was associated with hospital mortality. However, it is a modest predictor of outcome, offering similar discrimination to a prehospital critical illness score.

Tissue oximetry by near-infrared spectroscopy in a porcine model of out-of-hospital cardiac arrest and resuscitation

INTRODUCTION

Monitoring during resuscitation remains relatively crude. Near-infrared spectroscopy (NIRS) measures aggregate oxygen saturation in a volume of tissue. We assessed the utility of continuous StO2 measurement in a porcine model of cardiac arrest, and explored the effects of differential vasoconstriction on StO2. We hypothesized that (1) StO2 trends correspond with the onset of loss of pulses, resuscitation, and return of spontaneous circulation (ROSC); (2) epinephrine has a dose-dependent effect on StO2.

METHODS

We anesthetized and instrumented 7 female swine, placing a NIRS probe on the left forelimb to recorded StO2. After 8 min of untreated VF and 2 min of CPR, we randomized animals to 0.015 mgkg(-1) (SDE) or 0.1mgkg(-1) (HDE) epinephrine. After 3 min of CPR, animals were defibrillated. Animals with ROSC were given SDE, then HDE for subsequent hemodynamic deteriorations. Data were analyzed with descriptive statistics and generalized linear model (alpha=0.05) to determine overall slope of pooled StO2 across animals for resuscitation segments.

RESULTS

Four animals received HDE and three SDE. All achieved ROSC. Significant coefficients (ΔStO2 min(-1)) were noted for resuscitation segments. StO2 decreased after loss of pulses (-29.1; 95%CI -33.4, -24.7; p<0.01) but plateaued during CPR (-0.2; 95%CI -1.2, 0.8; p=0.71). There was a graded decline in StO2 between SDE (-1.3; 95%CI -1.5, -1.2; p<0.01) and HDE (-3.1; 95%CI -5.8, -0.4; p=0.03). The slowest change occurred with ROSC (0.4; 95%CI 0.3, 0.5; p<0.01).

CONCLUSIONS

In a porcine model of OHCA, peripheral StO2 rapidly decreased after loss of pulses, but did not improve with CPR or epinephrine. It increased extremely slowly after ROSC.

Potential utility of near-infrared spectroscopy in out-of-hospital cardiac arrest: an illustrative case series

OBJECTIVE

We evaluated the measurement of tissue oxygen content (StO(2)) by continuous near-infrared spectroscopy (NIRS) during and following cardiopulmonary resuscitation (CPR) and compared the changes in StO(2) and end-tidal carbon dioxide (ETCO(2)) as a measure of return of spontaneous circulation (ROSC) or rearrest.

METHODS

This was a case series of five patients who experienced out-of hospital cardiac arrest. Patients included those who had already experienced ROSC, who were being transported to the hospital, or who were likely to have a reasonable amount of time remaining in the resuscitation efforts. Patients were continuously monitored from the scene using continuous ETCO(2) monitoring and a NIRS StO(2) monitor until they reached the hospital. The ETCO(2) and StO(2) values were continuously recorded and analyzed for comparison of the time points when patients were clinically identified to have ROSC or rearrest.

RESULTS

Four of five patients had StO(2) and EtCO(2) recorded during an episode of CPR and all were monitored during the postarrest period. Three patients experienced rearrest en route to the hospital. Downward trends were noted in StO(2) prior to each rearrest, and rapid increases were noted after ROSC. The StO(2) data showed less variance than the ETCO(2) data in the periarrest period.

CONCLUSIONS

This preliminary study in humans demonstrates that StO(2) dynamically changes during periods of hemodynamic instability in postarrest patients. These data suggest that a decline in StO(2) level may correlate with rearrest and may be useful as a tool to predict rearrest in post-cardiac arrest patients. A rapid increase in StO(2) was also seen upon ROSC and may be a better method of identifying ROSC during CPR than pauses for pulse checks or ETCO(2) monitoring.

Less encouraging lessons from the front lines: barriers to implementation of an emergency department-based HIV screening program

OBJECTIVE

We describe barriers to, and discuss recommendations for, implementing a limited emergency department (ED)-based HIV screening program.

METHODS

A pilot program was designed to study the feasibility of integrating HIV screening into ED care among patients aged 18 to 64 years at an urban academic emergency department with an annual census of 50,000 patients.

RESULTS

During the first 12 weeks of the pilot program, 395 patients were screened. Of those, 2 (0.5%; 95% confidence interval 0.06% to 1.8%) received a positive test result for HIV. Both were contacted by telephone, and one was seen for result notification, posttest counseling, and further care in the local health department. Of the patients who received a negative test result, 98% were contacted about their results. We encountered numerous barriers to implementation, which we categorized as departmental, public health, legal, institutional, test limitations, and infrastructure.

CONCLUSION

Understanding potential barriers and making plans for dealing with them are critical to the successful implementation of an HIV screening program in the ED.

Sleep quality and fatigue among prehospital providers

BACKGROUND

Fatigue is common among medical professionals and has been linked to poor performance and medical error. Objective. To characterize sleep quality and its association with severe fatigue in emergency medical services (EMS) providers.

METHODS

We studied a convenience sample of EMS providers who completed three surveys: the Pittsburgh Sleep Quality Index (PSQI), the Chalder Fatigue Questionnaire (CFQ), and a demographic survey. We used established measures to examine survey psychometrics and performed t-tests, analysis of variance (ANOVA), and chi-square tests to identify differences in PSQI and CFQ scores.

RESULTS

One hundred nineteen surveys were completed. The eight-hour shift was most commonly reported (35.4%). A majority of subjects were overweight (41.9%) or obese (42.7%), and 59.6% had been diagnosed with one or more health conditions (e.g., diabetes). Results from psychometric tests were positive. The mean (+/- standard deviation) PSQI score was 9.2 (+/- 3.7). A CFQ score > or =4, indicating severe mental and physical fatigue, was present in 44.5% of the subjects. The mean PSQI score was higher among those reporting severe fatigue (11.3 +/- 3.2) than among those not reporting fatigue (7.5 +/- 3.0, p < 0.0001).

CONCLUSIONS

The results from this study suggest that the sleep quality and fatigue status of EMS workers are at unhealthy levels. The health and safety of the EMS worker and patient population should be considered in light of these results.

Effects of an Impedance Threshold Device on Hemodynamics andRestoration of Spontaneous Circulation in Prolonged Porcine Ventricular Fibrillation

BACKGROUND

An impedance threshold device (ITD) has been designed to enhance circulation during CPR by creating a negative intrathoracic pressure during the relaxation phase of chest compression.

HYPOTHESIS

We sought to determine the effects of the ITD on coronary perfusion pressure (CPP), return of spontaneous circulation (ROSC), and short-term survival (20 minutes after ROSC). We hypothesized that the ITD would improve all 3 variables when compared to standard CPR.

METHODS

Using a case-control design nested within a randomized primary study, we compared CPR with the ITD (ITD-CPR) to standard CPR without the device (S-CPR). We systematically assigned 36 domestic swine, weighing 23-29 kg, (18 per group) to resuscitation with either ITD-CPR or S-CPR after 8 minutes of untreated ventricular fibrillation (VF). At minute 8, mechanical chest compression and ventilation began, and drugs (0.1 mg/kg epinephrine, 40U vasopressin, 1.0 mg propranolol, 1 mEq/kg sodium bicarbonate) were given. The first rescue shock (150J biphasic) was delivered at minute 11 of VF. We recorded CPP, ROSC (systolic pressure > 80 mmHg sustained for 60 s continuously), and survival. Data were analyzed with Fisher's exact test and generalized estimating equations (GEE), with alpha = 0.05.

RESULTS

We analyzed 3,150 compressions. CPP for the ITD-CPR group (28.1 mmHg [95% CI 27-29.3 mmHg]), did not differ from the S-CPR group (32.3 mmHg [95% CI 31.2-33.4 mmHg]). ROSC occurred in 6/18 (33%) animals in the ITD-CPR, and 14/18 (78%) in the S-CPR group (p = 0.02). Survival occurred in 3/18 (17%) ITD-CPR and 13/18 (72%) S-CPR group (p = 0.003).

CONCLUSIONS

ITD-CPR did not improve CPP compared to S-CPR. ROSC and survival were significantly lower with ITD-CPR.

Association of intramyocardial high energy phosphate concentrations with quantitative measures of the ventricular fibrillation electrocardiogram waveform

BACKGROUND

Quantitative measures of the ventricular fibrillation (VF) electrocardiogram (ECG) have been correlated with the success of rescue shocks, making them ideal measures for guiding resuscitative interventions. Correlation of intramyocardial energy stores with the change in quantitative VF ECG measures would provide mechanistic insight into their utility. We sought to investigate the relationship between intramyocardial energy stores and four quantitative ECG measures.

METHODS

Eighteen mixed-breed, domestic swine were sedated, anaesthetized and paralyzed. Swine were block randomized into three groups receiving 5, 10, or 15 min of untreated VF. Thoracotomy was performed and the heart was delivered. VF was induced by a 100 mA transthoracic shock while ECG was recorded. Biopsies of myocardial tissue were taken from the left and right ventricles after the prescribed duration of VF. Adenosine triphosphate (ATP) and adenosine diphosphate (ADP) concentrations in the tissue samples were measured. ECG data immediately prior to each biopsy were analyzed by each of four quantitative ECG methods: Scaling Exponent (ScE), Median Slope (MS), Amplitude Spectrum Area (AMSA), and logarithm of the Absolute Correlation (LAC). ATP and ADP concentrations of VF duration groups were compared. ATP and ADP concentrations were regressed against each quantitative ECG measure.

RESULTS

ATP concentrations differed between VF duration groups, but ADP concentrations differed only between 5 and 10 min groups. A significant association existed between ATP and three quantitative measures--ScE, MS, and AMSA--but no significant relationship was found for ADP.

CONCLUSION

Intramyocardial ATP levels correlate with quantitative measures of the ECG during ventricular fibrillation.

Effects of pre-arrest and intra-arrest hypothermia on ventricular fibrillation and resuscitation

BACKGROUND

Hypothermia has been shown to improve survival and neurological outcomes for ventricular fibrillation (VF) cardiac arrest. The electrophysiological mechanisms of hypothermia are not well-understood, nor are the effects of beginning cooling during the resuscitation.

METHODS AND RESULTS

We hypothesized that inducing hypothermia prior to the onset of VF would slow the deleterious changes seen in the ECG during VF and that inducing hypothermia at the start of resuscitation would increase the rates of ROSC and short-term survival in a porcine model of prolonged VF. We randomly assigned 42 domestic swine (27.2+/-2.3 kg) to either pretreatment with hypothermia before induction of VF (PRE), normothermic resuscitation (NORM) or intra-resuscitation hypothermia (IRH). During anesthesia, animals were instrumented via femoral cutdown. Lead II ECG was recorded continuously. PRE animals were cooled before the induction of VF, with a rapid infusion of 4 degrees normal saline (30mL/kg). VF was induced electrically, left untreated for 8min, then mechanical CPR began. During CPR the NORM animals got 30mL/kg body-temperature saline and the IRH animals got 30mL/kg 4 degrees saline. In all groups first rescue shocks were delivered after 13min of VF. We calculated the VF scaling exponent (ScE) for the entire 8min period (compared using GEE). ROSC and survival were compared with Fisher's exact test. Mean temperature in degrees C at the onset of VF was PRE=34.7 degrees (+/-0.8), NORM=37.8 (+/-0.9), and IRH=37.9 (+/-0.9). The ScE values over time were significantly lower after 8min in the PRE group (p=0.02). ROSC: PRE=10/14 (71%), NORM=6/14 (43%) and IRH=12/14 (86%); p for IRH vs. NORM=0.02. Survival: PRE=9/14 (64%), NORM=5/14 (36%), IRH 8/14 (57%).

CONCLUSION

Hypothermia slowed the decay of the ECG waveform during prolonged VF. IRH improved ROSC but not short-term survival compared to NORM. It is possible to rapidly induce mild hypothermia during CPR using an IV infusion of ice-cold saline.

Prevalence of Staphylococcus aureus nasal colonization in emergency department personnel

STUDY OBJECTIVE

Nasal colonization with Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA) can precede infection in patients and contacts. Although general population S aureus/MRSA rates are well described, the prevalence of S aureus and MRSA nasal colonization in emergency department health care workers is not defined. We seek to determine the prevalence of S aureus and MRSA nasal colonization among ED health care workers without evidence of an active site of staphylococcal infection and identify variables associated with colonization.

METHODS

We prospectively studied a convenience sample of ED health care workers from 5 urban teaching hospitals in Pittsburgh, PA. Each participant completed a questionnaire and nasal culturing. We tested susceptibility with the oxacillin disc diffusion method. We analyzed data with descriptive statistics and univariate regression, with alpha set at 0.05.

RESULTS

Of 255 subjects, 23% were physicians; 62% were nurses, nursing assistants, or patient care technicians; and 15% were clerical staff or social service workers. Of 81 (31.8%) S aureus isolates, 11 (13.6%) were MRSA, an overall prevalence of 4.3%. All positive MRSA samples were from nurses, nursing assistants, or patient care technicians. No other covariate had an association with S aureus or MRSA colonization.

CONCLUSION

In this urban ED health care worker population, the prevalence of S aureus is similar but MRSA nasal colonization is higher than previously reported estimates in the general population of the United States. Physicians and nonpatient contact ED health care workers did not have MRSA colonization.

Peripheral myelin of Xenopus laevis: role of electrostatic and hydrophobic interactions in membrane compaction

P0 glycoprotein is the major structural protein of peripheral nerve myelin where it is thought to modulate inter-membrane adhesion at both the extracellular apposition, which is labile upon changes in pH and ionic strength, and the cytoplasmic apposition, which is resistant to such changes. Most studies on P0 have focused on structure-function correlates in higher vertebrates. Here, we focused on its role in the structure and interactions of frog (Xenopus laevis) myelin, where it exists primarily in a dimeric form. As part of our study, we deduced the full sequence of X. laevis P0 (xP0) from its cDNA. The xP0 sequence was found to be similar to P0 sequences of higher vertebrates, suggesting that a common mechanism of PNS myelin compaction via P0 interaction might have emerged through evolution. As previously reported for mouse PNS myelin, a similar change of extracellular apposition in frog PNS myelin as a function of pH and ionic strength was observed, which can be explained by a conformational change of P0 due to protonation-deprotonation of His52 at P0's putative adhesive interface. On the other hand, the cytoplasmic apposition in frog PNS myelin, like that in the mouse, remained unchanged at different pH and ionic strength. The contribution of hydrophobic interactions to stabilizing the cytoplasmic apposition was tested by incubating sciatic nerves with detergents. Dramatic expansion at the cytoplasmic apposition was observed for both frog and mouse, indicating a common hydrophobic nature at this apposition. Urea also expanded the cytoplasmic apposition of frog myelin likely owing to denaturation of P0. Removal of the fatty acids that attached to the single Cys residue in the cytoplasmic domain of P0 did not change PNS myelin structure of either frog or mouse, suggesting that the P0-attached fatty acyl chain does not play a significant role in PNS myelin compaction and stability. These results help clarify the present understanding of P0's adhesion role and the role of its acylation in compact PNS myelin.

Alterations of prostate biomarker expression and testosterone utilization in human LNCaP prostatic carcinoma cells by garlic-derived S-allylmercaptocysteine

BACKGROUND

This study determined the effects of S-allylmercaptocysteine (SAMC), a phytoconstituent from garlic, on the expression of androgen-responsive biomarkers, prostate specific antigen (PSA), and prostate specific membrane antigen (PSMA), in human prostatic carcinoma cells (LNCaP).

METHODS

Secretion of PSA was determined as well as the activity of PSMA measured as a function of its ability to hydrolyze poly-gamma-glutamated folate and N-acetylaspartylglutamate (NAAG). Folate hydrolase capacity was also determined in SAMC-treated cells grown in charcoal stripped fetal calf serum (CS-FCS). In addition, testosterone disappearance was measured from culture media of SAMC-treated LNCaP and PC-3 cells as well as from cell free lysates.

RESULTS

PSA secretions were significantly decreased compared to control values at 1 day (8.4 +/- 2.6 vs. 18.9 +/- 1.7, P < 0.01), 4 days (18.9 +/- 5.3 vs. 73.8 +/- 4. 4, P < 0.001), and 6 days (35.6 +/- 2.1 vs. 96.5 +/- 17.9 ng/10(5) cells, P < 0.01; mean +/- SD). By contrast, PSMA activity measured as either folate hydrolase or NAAG dipeptidase (NAALADase) activity increased in cells treated with SAMC. PSMA-folate hydrolase activity in SAMC-treated cells grown in CS-FCS increased beyond that observed in cells grown in CS-FCS alone. Pre-exposure of LNCaP cells to SAMC resulted in enhanced rate of testosterone disappearance from culture media at 6 hr (P < 0.01) and at 48 hr (P < 0.001) compared to media from cells not previously exposed to SAMC. Results similar to these were also observed in androgen-independent PC-3 cells treated with SAMC. In lysates of SAMC-treated LNCaP cells, the rate of testosterone catabolism was twice that from phosphate buffered saline (PBS)-treated cells. SAMC-treated LNCaP cells grown in media supplemented with testosterone temporarily exhibited enhanced growth over a 2 day period but cell numbers declined later to levels similar to those of SAMC treatment.

CONCLUSIONS

These results show that SAMC exhibits differential effects on recognized biomarkers for LNCaP cells similar to those produced by androgen deprivation and strongly suggests that this effect may be mediated, in part, by diminishing the trophic effects of testosterone, likely by converting it to metabolites less reactive toward androgen receptors.

Prostate-specific membrane antigen: a novel folate hydrolase in human prostatic carcinoma cells

A novel monoclonal antibody has been developed that reacts strongly with human prostatic cancer, especially tumors of high grade. This antibody (7E11C-5) is currently in Phase 3 trials as an imaging agent for metastatic disease. We have cloned the gene that encodes the antigen that is recognized by the 7E11C-5 monoclonal antibody and have designated this unique protein prostate-specific membrane (PSM) antigen. PSM antigen is a putative class II transmembranous glycoprotein exhibiting a molecular size of Mr 94,000. Functionally, class II membrane proteins serve as transport or binding proteins or have hydrolytic activity. Preliminary studies have demonstrated binding of pteroylmonoglutamate (folate) to membrane fractions that also cross-reacted with the PSM monoclonal antibody. We observed substantial carboxypeptidase activity as folate hydrolase associated with PSM antigen. The purpose of our study was to demonstrate that human prostatic carcinoma cells expressing PSM antigen exhibit folate hydrolase activity using methotrexate triglutamate (MTXGlu3) and pteroylpentaglutamate (PteGlu5) as substrates. Isolated membrane fractions from four human prostate cancer cell lines (LNCaP, PC-3, TSU-Prl, and Duke-145) were examined for folate hydrolase activity using capillary electrophoresis. After timed incubations at various pH ranges and in the presence and absence of thiol reagents, separation of pteroyl(glutamate)n derivatives was achieved with an electrolyte of sodium borate and SDS, while absorbance was monitored at 300 nm. The results demonstrate clearly that LNCaP cells, which highly express PSM, hydrolyze gamma-glutamyl linkages of MTXGlu3. The membrane-bound enzyme is an exopeptidase, because it progressively liberates glutamates from MTXGlu3 and PteGlu5 with accumulation of MTX and PteGlu1, respectively. The semipurified enzyme has a broad activity from pH 2.5 to 9.5 and exhibits activity maxima at pH 5 and 8. Enzymatic activity is maintained in the presence of reduced glutathione, homocysteine, and p-hydroxymercuribenzoate (0.05-0.5 mm) but was inhibited weakly by DTT (>/=0.2 mm). By contrast to LNCaP cell membranes, membranes isolated from other human prostate adenocarcinoma cells (PC-3, Duke-145, and TSU-Pr1) did not exhibit comparable hydrolase activity, nor did they react with 7E11-C5 monoclonal antibody. After transfection of PC-3 cells with a full-length 2.65-kb PSM cDNA subcloned into a pREP7 eukaryotic expression vector, non-PSM antigen-expressing PC-3 cells developed immunoreactivity to 7E11-C5 monoclonal antibody and demonstrated folate hydrolase activities and optimum pH activity profiles identical to those of LNCaP cells. The membrane-bound enzymes from both LNCaP- and PC-3-transfected cells also have a capacity to hydrolyze an alpha-linked glutamyl moiety from N-acetyl-alpha-aspartylglutamate. We have identified that PSM antigen is a pteroyl poly-gamma-glutamyl carboxypeptidase (folate hydrolase) and is expressed strongly in human prostate cancer. Cancer cells that express this enzyme are resistant to methotrexate therapy. Those developing future therapeutic strategies in the treatment of prostate cancer that utilize folate antagonists need to consider this mechanism of resistance.