Optimizing care pathways: A study of the urgent dispatch program and its impact on emergency department visits.

INTRODUCTION: The use of acute hospital-level care at home (hospital-at-home) for patients who are chronically ill has led to decreased medical costs, amount of sedentary time, and hospital admissions. Our large integrated healthcare system identified the need to develop a mechanism through which to decrease emergency department (ED) visits in this patient population by creating a home acute care program called Urgent Dispatch. The primary objective of this study was to determine the medical condition for referral and seven and 30-day ED visit rates. METHODS: This was a retrospective cohort of all patients referred to the Urgent Dispatch program from April 1, 2021, through February 28, 2022. We assessed encounters for patient demographics, referral source, reason for visit, number of at home visits, total number of days in the program, and determined if the patient had an ED encounter within seven and 30 days of participation in the program. The healthcare system includes 10 hospitals (academic, community and rural), 17 emergency departments (hospital-based and freestanding) and their associated outpatient clinics. RESULTS: A total of 2218 orders were placed with 1530 (70.8 %) resulting in enrollment in the Urgent Dispatch program. The majority were elderly (75 ± 15.6), white (70 %), female (64.4 %), and had Medicare as their primary insurance (82 %). The average number of visits made by Urgent Dispatch was 1.46 (SD ± 0.95). The average number of days enrolled in the program was 2.4 (SD ± 4.1). The top three referral sources to the program were outpatient primary care (42 %), home care (28 %) and emergency medicine (20 %). The top body systems requiring a visit were cardiovascular (22 %), general (18 %), and respiratory (17.2 %). Of the 1530 urgent dispatch referrals, 19.8 % (n = 303) had an ED visit within seven days, 12 % (n = 183) had an ED visit within eight to 30 days, and 68.2 % (n = 1044) had no ED visit. CONCLUSION: A home-based care model of healthcare delivery for patients with chronic medical conditions can provide effective care, with 80.2 % of patients avoiding an ED visit within seven days and 68.2 % avoiding an ED visit within 30 days.

Ultrasound guidance for real-time management of acute ischemic priapism.

Ischemic priapism is a relatively uncommon genitourinary condition that, if left untreated, can lead to permanent erectile dysfunction. Detumescence should ideally be attained within the first 36 h of onset to avoid irreversible fibrosis and necessary surgery. Opportunities to practice medical management of this condition are scarce, and the risk of iatrogenic injury of vessels, nerves, and urethra can be significant if performed blind. Visualizing these structures through ultrasonography can reduce the risk of injury and aid in the confirmation of drug delivery. This novel utilization of ultrasound guidance in active treatment can help improve physician confidence and success in managing this rare and urgent condition. To our knowledge, this is the first report of point-of-care ultrasound-guided penile nerve block used to manage pain associated with priapism. We present a 44-year-old male presenting with a painful erection lasting for eight hours. Penile doppler ultrasound was performed concurrent with medical management of priapism, with successful detumescence and discharge.

Impact of Triage Systems on Time to Diagnosis and Treatment of Traumatic Brain Injuries.

BACKGROUND: Intracerebral hemorrhage (ICH) is a potential complication from traumatic brain injury, with a 30-day mortality rate of 35-52%. Rapid diagnosis allows for earlier treatment, which impacts patient outcomes. A trauma activation (TA) is called when injury severity meets institutional criteria. The patient is immediately roomed, and a multispecialty team is present. A trauma evaluation (TE) occurs when injuries are identified after standard triage processes. OBJECTIVES: Our aim was to determine whether TA patients with ICH were diagnosed and treated more rapidly than TE patients. METHODS: This was a retrospective study of patients presenting to trauma centers within a large hospital system diagnosed with traumatic ICH between January 2018 and December 2018. Patients were categorized as TA or TE patients. The time to diagnosis was compared between groups, and additional times were evaluated, including time to imaging, computed tomography interpretation, and treatment. RESULTS: A total of 294 patients were included. Groups had similar demographic characteristics and medical history; there was no difference in head Abbreviated Injury Score, Injury Severity Score, or anticoagulant use. Time to diagnosis was decreased for TA patients compared with TE patients (p < 0.0001). In addition, TA patients received treatment sooner (median 107 min) than TE patients (184.5 min) (p < 0.0001). CONCLUSIONS: Diagnosis and treatment times were significantly faster in TA patients than in TE patients. Given the similarities in injury severity between groups, the increased time to treatment may be detrimental for patients. Trauma activations are a resource-heavy process, but TE delays care. These data suggest that an intermediary process may be beneficial.

Computed Tomography Utilization for Patients Presenting with Chest Pain.

INTRODUCTION: Computed tomography (CT) is routinely used in the emergency department (ED) due to its ease of access and its ability to rapidly rule in or out many serious conditions. Freestanding emergency departments (FSEDs) have become increasingly used as an alternative to hospital-based emergency departments (HBEDs). The objective of this study was to investigate if the utilization rate of CT differs between FSEDs and HBEDs for chest pain. METHODS: A retrospective evaluation of patients presenting to 17 EDs within a large integrated healthcare system between May 1, 2019 - April 30, 2021 with a chief complaint chest pain. Categorical variables are presented as frequencies and percentages. Continuous variables are presented as mean and standard deviation. Multiple logistic regression was used to assess the effect of facility on CT utilization for chest pain. RESULTS: There were 67,084 patient encounters included in the study. Patients were predominately female (55%), white (61%), and insured through Medicare/Medicaid (59%). After controlling for predictive variables which included Charlson Comorbidity Index, ESI, age, sex, and race, patients who presented to FSEDs with chest pain were less likely to have a CT than those who presented to a HBED (AOR = 0.85, CI (0.81-0.90). CONCLUSION: CT scans of the chest are utilized less frequently at FSEDs compared to HBEDs for patient presenting with chest pain.

Large-scale Implementation of Fascia Iliaca Compartment Blocks in an Emergency Department.

INTRODUCTION: A robust body of literature supports the use of fascia iliaca compartment blocks (FICB) for improving outcomes in hip fractures, especially in the geriatric population. Our objective in this project was to implement consistent pre-surgical, emergency department (ED) FICB for hip fracture patients and to address barriers to implementation. METHODS: With the support of a multidisciplinary team, including orthopedic surgery and anesthesia, a core team of emergency physicians developed and implemented a departmentwide FICB training and credentialing program. The goal was to have 80% of all emergency physicians credentialed to provide pre-surgical FICB to all hip fracture patients seen in the ED who met the criteria. Following implementation, we assessed approximately one year of data on hip fracture patients presenting to the ED. We evaluated whether or not they were eligible for FICB and, if so, whether or not they received it. RESULTS: Emergency physician education has resulted in 86% of clinicians credentialed to perform FICB. Of 486 patients presenting for hip fracture, 295 (61%) were considered eligible for a block. Of those eligible, (54%) consented and underwent a FICB in the ED. CONCLUSION: A collaborative, multidisciplinary effort is vital for success. The primary barrier to achieving a higher percentage of eligible patients receiving blocks was the deficit of emergency physicians initially credentialed. Continuing education is ongoing, including credentialing and early identification of patients eligible for the fascia iliaca compartment block.

DO HIGHER DOSES OF NALOXONE INCREASE THE RISK OF PULMONARY COMPLICATIONS?

BACKGROUND: Although naloxone has proven to be an effective opioid reversal agent, concern that high doses of naloxone can cause pulmonary edema may prevent health care providers from administering it in initial high doses. OBJECTIVE: Our aim was to determine whether increased doses of naloxone are correlated with an increase in pulmonary complications in patients presenting to the emergency department (ED) after an opioid overdose. METHODS: This was a retrospective study of patients treated with naloxone by emergency medical services (EMS) or in the ED at an urban level I trauma center and three associated freestanding EDs. Data were queried from EMS run reports and the medical record and included demographic characteristics, naloxone dosing, administration route, and pulmonary complications. Patients were grouped by naloxone dose received, defined as low (≤ 2 mg), moderate (> 2 mg to ≤ 4 mg), and high (> 4 mg). RESULTS: Of the 639 patients included, 13 (2.0%) were diagnosed with a pulmonary complication. There was no difference in the development of pulmonary complications across groups (p = 0.676). There was no difference in pulmonary complications based on the route of administration (p = 0.342). The administration of higher doses of naloxone was not associated with longer hospital stays (p = 0.0327). CONCLUSIONS: Study results suggest that the reluctance of many health care providers to administer larger doses of naloxone on initial treatment may not be warranted. In this investigation, there were no poor outcomes associated with an increase in naloxone administration. Further investigation in a more diverse population is warranted.

Patients utilizing emergency medical services - Does facility type matter?

BACKGROUND: Emergency departments (EDs) play a critical role in the US healthcare system. As freestanding EDs (FSEDs) are integrated into the acute care landscape, local EMS providers are transporting to these facilities, which may be closer in proximity and provide faster turnaround times. We hypothesized that patients transported via EMS to a freestanding ED required fewer tests and are admitted less frequently than those transported to a HBED. Our objective was to compare testing frequency and admission rates between patients transported via EMS to a FSED vs. HBED. METHODS: This was a retrospective cohort study of all patients who presented within a large integrated hospital system via EMS to one of 10 HBEDs or one of 6 FSEDs between April 1, 2020 - May 1, 2021. Categorical variables are presented as frequencies and percentages and comparisons between groups were obtained using chi squared tests. Continuous variables are presented as mean and standard deviation and p-values comparing groups were obtained using t-tests. Multiple logistic regression was used to assess the effect of ED type on admission status, labs ordered, and testing performed. RESULTS: A total of 123,120 encounters were included in our study. Mean age at the FSEDs was 59.9 vs. 61.3 at the HBEDs. At the FSEDs 55.6% (n = 4675) were female vs. 53.0% (n = 60,809) at the HBEDs. At the FSEDs 82.0% (n = 6805) were White vs. 60.7% (n = 68,430) at the HBEDs. We found 50.0% (n = 3974) had Medicare at the FSEDs vs 50.9% (n = 55,372) at the FSEDs. At the FSEDs, 69.5% (n = 5846) had bloodwork vs. 82.4% (n = 94,512) at the HBEDs; 68.3% (n = 5745) had an x-ray at the FSEDs vs. 70.7% (n = 81,089) at the HBEDs; 40.1% (n = 3370) had a CT scan at the FSEDs vs. 44.9% (n = 51,503) at the HBEDs; and 40.6% (n = 3412) were admitted at the FSEDs vs. 56.1% (n = 64,355) at the HBEDs. After controlling for Charlson Comorbidity Index, acuity, age, gender, sex, insurance and race, patients in FSEDs were 35% less likely to be admitted as compared to HBEDs. CONCLUSION: Patients brought in via EMS to a FSED were less likely to have blood work, x-ray, or CT scan, and were less likely to be admitted to the hospital than those transported to a HBED.

The impact of COVID-19 on emergency department boarding and in-hospital mortality.

INTRODUCTION: The COVID-19 pandemic has been challenging for healthcare systems in the United States and globally. Understanding how the COVID-19 pandemic has impacted emergency departments (EDs) and patient outcomes in a large integrated healthcare system may help prepare for future pandemics. Our primary objective was to evaluate if there were changes to ED boarding and in-hospital mortality before and during the COVID-19 pandemic. METHODS: This was a retrospective cohort study of all patients ages 18 and over who presented to one of 17 EDs (11 hospital-based; 6 freestanding) within our healthcare system. The study timeframe was March 1, 2019- February 29, 2020 (pre-pandemic) vs. March 1, 2020-August 31, 2021 (during the pandemic). Categorical variables are described using frequencies and percentages, and p-values were obtained from Pearson chi-squared or Fisher's exact tests where appropriate. In addition, multiple regression analysis was used to compare ED boarding and in-hospital mortality pre-pandemic vs. during the pandemic. RESULTS: A total of 1,374,790 patient encounters were included in this study. In-hospital mortality increased by 16% during the COVID-19 Pandemic AOR 1.16(1.09-1.23, p < 0.0001). Boarding increased by 22% during the COVID-19 pandemic AOR 1.22(1.20-1.23), p < 0.0001). More patients were admitted during the COVID-19 pandemic than prior to the pandemic (26.02% v 24.97%, p < 0.0001). Initial acuity level for patients presenting to the ED increased for both high acuity (13.95% v 13.18%, p < 0.0001) and moderate acuity (60.98% v 59.95%, p < 0.0001) during the COVID-19 pandemic. CONCLUSION: The COVID-19 pandemic led to increased ED boarding and in-hospital mortality.

Race and Sex Are Associated With Variations in Pain Management in Patients Presenting to the Emergency Department With Undifferentiated Abdominal Pain.

BACKGROUND: Pain management is critical to the management of patients in the emergency department (ED). The clinical decision-making process for prescribing medications is complicated by its subjective nature. Historically, racial and ethnic minority groups and women have not had their pain managed as aggressively as White and male patients. OBJECTIVE: The objective of this study was to determine whether race and biological sex affect the pain management process by means of evaluating data from a large hospital system with diverse patient demographic characteristics. METHODS: This was a retrospective study of adult patients who presented an ED within the hospital system and were discharged from the ED with a diagnosis of undifferentiated abdominal pain during a single year. Patient pain was classified as mild, moderate, or severe, and patients were further stratified by race, ethnicity, sex, and insurance status. Pain management was assessed by narcotic vs non-narcotic administration. RESULTS: A total of 32,676 patients were included in the study. Narcotic administration was more likely in White patients with undifferentiated abdominal pain (22%) compared with Black patients (12%; adjusted odds ratio 0.50; 95% CI 0.46-0.54). This persists across patient-reported pain scores. In addition, women (16.99%) were prescribed narcotics less often than men (19.41%; p < 0.0001). CONCLUSIONS: Although differences in pain management practices have been explored previously, this study provided a large, updated, multifacility assessment that confirmed that race- and sex-based differences in pain management persist, specifically in the decision to treat with narcotics. Further investigation is warranted to determine the root causes of these differences.

Do racial disparities exist at various time points during an emergency department visit for chest pain.

INTRODUCTION: It is well documented that disparities in patient care based on race and ethnicity are prevalent in the emergency medical care setting. In most cases these evaluations are patient focused and outcome based. The timeliness of patient treatment in the emergency department (ED) is correlated with patient outcomes. In this study, we sought to evaluate whether the timeliness of care for patients with chest pain across stages of care was impacted by patient race. METHODS: This was a retrospective evaluation of ED throughput times including adults who presented to one of seventeen EDs in a large healthcare system from January 1, 2019 to December 31, 2019 and met criteria for inclusion. The effect of race on different intervals of care were assessed. Generalized Linear Models were used to estimate the effect of race on different intervals of care while controlling for Charlson Comorbidity index, age, gender, insurance, ED facility type and emergency severity index acuity level. RESULTS: A total of 28,705 patients were included, with a mean age of 54 ± 18 years. The majority of patients were White (63%), female (56%) and had Medicare or Medicaid (56%). Black patients experienced significantly increased wait times for resident physician examination, advanced practice provider examination, attending physician examination, and ED disposition. There was no difference in time to triage between Black patients and White patients. CONCLUSION: Black patients have longer wait times for resident physician evaluation, advanced practice provider evaluation, attending physician evaluation, and ED disposition when presenting to the ED with chest pain.

Multiregion Trauma Center Follow-Up Protocol for Transferred Trauma Patients.

BACKGROUND: Trauma centers routinely utilize the Injury Severity Score for performance improvement. Yet, transferring facilities do not always have access to patients' final Injury Severity Score. OBJECTIVE: The purpose of this project was to develop and implement a multiregion Injury Severity Score follow-up feedback protocol for transferring facilities to receive standardized information on patient treatment and the ability to calculate an accurate follow-up Injury Severity Score of transferred patients. METHODS: This project included 25 Adult and Pediatric Level I, II, and III trauma centers within three regional trauma systems in a Midwestern state. This project included trauma centers that used one of the two different trauma registry software systems as a solution to develop and implement a protocol for follow-up feedback for transferred trauma patients. A template was created to capture data posttransfer to calculate a final Injury Severity Score. RESULTS: The feedback protocol was well received by participating regions. Implementation revealed the impact of variable trauma registry software on the ability to create multi-institution feedback programs. CONCLUSION: Trauma systems can implement similar strategies to ensure transferring trauma centers routinely receive standardized, timely patient feedback.

Reduced mortality and faster treatment in sepsis seen at freestanding vs. hospital-based emergency departments.

INTRODUCTION: Freestanding Emergency Departments (FEDs) have grown in number and understanding their impact on the healthcare system is important. Sepsis causes significant morbidity and mortality and identifying how FEDs impact sepsis morbidity and mortality has not been studied. The objective of this study was to determine if there is a difference in in-hospital mortality for sepsis patients who present initially to FEDs compared to a hospital-based ED. METHODS: This was a retrospective cohort of adult patients seen at a hospital-based ED or one of three FEDs within a large hospital system from 1/1/2018-10/31/2020. We included those who were diagnosed with sepsis, severe sepsis or septic shock and evaluated ED throughput measures, in-hospital mortality, and hospital length of stay. Categorical variables are presented as frequencies and percentages. Continuous variables are presented as mean and standard deviations or median and quartiles depending on distribution. Multiple logistic regression was fit to compare in-hospital mortality rates between the two groups. Variables controlled for included Charlson Comorbidity Index, race, gender, insurance, and sepsis severity. Wilcoxon rank sum tests were used to compare the time metrics. RESULTS: There were 1955 patients included in the study. Mean age of participants was 61.9 at the FEDs vs 63.7 at the HBED. Majority of the participants were white; 88.2% at the FED vs. 77.3% at the HBED; and male 49.0% at the FED vs. 51.1% at the HBED. Most patients had Medicare; 45.4% at the FED vs. 58.3% at the HBED. In-patient mortality rate was significantly lower for patients that presented to FEDs compared to HBED (95%CI 0.13-0.46) adjusted odds ratio 0.24. Time to IV fluids, time to lactate, time to blood cultures, time to ED disposition, ED LOS, time to arrival on the inpatient unit were all significantly lower for FEDs vs HBED (p < 0.05). CONCLUSION: Patients presenting to FEDs for sepsis, severe sepsis and septic shock had lower inpatient mortality, quicker treatment times, and were transferred and admitted to the hospital faster than patients seen at a HBED.

Improved hospital mortality rates after the implementation of emergency department sepsis teams.

INTRODUCTION: Sepsis is a leading cause of mortality with more than 700,000 hospitalizations and 200,000 deaths annually in the United States. Early recognition of sepsis is critical for timely initiation of treatment and improved outcomes. We sought to evaluate. in-hospital mortality rates of patients diagnosed with sepsis before and after implementation of emergency department (ED) sepsis teams. METHODS: This was a retrospective study of adult patients seen at a tertiary care ED diagnosed with sepsis and severe sepsis. Pre-implementation study time frame was 5/1/2018-4/30/2019 and post-implementation was 11/1/2019-9/30/2020. A six-month washout period was utilized after implementation of ED-based sepsis teams. Indications for sepsis team activation were: two systemic inflammatory response syndrome (SIRS) criteria with suspected infection or two SIRS with confirmed infection during workup. Categorical variables are presented as frequencies and percentages. Continuous variables are presented as mean and standard deviation or median and quartiles depending on distribution. Multiple logistic regression compared mortality rates pre- and post-implementation while controlling for Charlson comorbidity index. Secondary objectives included comparing time metrics pre- and post-implementation. Student t-tests compared normally distributed variables and Wilcoxon rank sum tests compared non-normally distributed variables. RESULTS: There were 1188 participants included in the study; 553 before implementation of sepsis teams and 635 after implementation. Mean age of participants was 64 years. Patients were 74.7% white and 22.6% black. Medicare was the most common health insurance (59%). Mortality rates were significantly lower post-implementation of sepsis teams compared to pre-implementation with an adjusted odds ratio of 0.472, (95%CI, 0.352-0.632). ED LOS (95%CI (-67.2--11.3), hospital LOS (95%CI, -1.0--0.002) and time to lactic acid (95%CI, -10.0- -3.0) and antibiotics (95%CI, -29.0--11.0) were all significantly lower after implementation. CONCLUSION: Implementation of ED sepsis teams decreased inpatient hospital mortality rates, ED length of stay and hospital length of stay.

A Survey-Based Assessment of "Matter of Balance" Participant Fall-Related Experience.

BACKGROUND: Falls are a substantial cause of injury in older adults, which can be attributed to progressive lack of physical activity, associated comorbidities, social isolation, and chronic health conditions. Fall prevention courses are designed to educate participants on fall safety and increase activity levels and social engagement. OBJECTIVE: The purpose of this study was to evaluate the perceived effectiveness of a nationally recognized fall prevention course on self-reported fall frequency and lifestyle habits. METHODS: This was a single-group pretest-posttest study of a convenience sample of older adults enrolled in a group fall prevention program, A Matter of Balance, in a community setting between March 2019 and March 2020. Questionnaires were distributed at the first and final sessions of the course to evaluate participant perceptions of the program and its impact on their fall history, exercise habits, and social engagement. Comparisons were made using Wilcoxon rank sum tests. RESULTS: A total of 40 class members agreed to participate, with 29 (73%) completing both the presurvey and the postsurvey. Responses indicated no change in the number of falls or participants following an established exercise routine. However, of those who fell prior to the course, 75% reported a reduction in falls. In addition, the participants reported an overall increase in weekly exercise frequency. In those who reported fear of falling, 71% reported a reduction in fear following the course. CONCLUSIONS: The participants in this study self-reported a decrease in fall rate, a decrease in fear of falling, and an increase in exercise frequency. The course is not fall protective but can be considered an adjunct to fall prevention measures that include medical, medication, visual, and environmental management.

Regulation of Locomotor activity in fed, fasted, and food-restricted mice lacking tissue-type plasminogen activator.

BACKGROUND: Circadian rhythms of physiology and behavior are driven by a circadian clock located in the suprachiasmatic nucleus of the hypothalamus. This clock is synchronized to environmental day/night cycles by photic input, which is dependent on the presence of mature brain-derived neurotrophic factor (BDNF) in the SCN. Mature BDNF is produced by the enzyme plasmin, which is converted from plasminogen by the enzyme tissue-type plasminogen activator (tPA). In this study, we evaluate circadian function in mice lacking functional tPA. RESULTS: tPA-/- mice have normal circadian periods, but show decreased nocturnal wheel-running activity. This difference is eliminated or reversed on the second day of a 48-h fast. Similarly, when placed on daily cycles of restricted food availability the genotypic difference in total wheel-running activity disappears, and tPA-/- mice show equivalent amounts of food anticipatory activity to wild type mice. CONCLUSIONS: These data suggest that tPA regulates nocturnal wheel-running activity, and that tPA differentially affects SCN-driven nocturnal activity rhythms and activity driven by fasting or temporal food restriction.

Urokinase-type plasminogen activator modulates mammalian circadian clock phase regulation in tissue-type plasminogen activator knockout mice.

Glutamate phase shifts the circadian clock in the mammalian suprachiasmatic nucleus (SCN) by activating NMDA receptors. Tissue-type plasminogen activator (tPA) gates phase shifts by activating plasmin to generate m(ature) BDNF, which binds TrkB receptors allowing clock phase shifts. Here, we investigate phase shifting in tPA knockout (tPA-/- ; B6.129S2-Plattm1Mlg /J) mice, and identify urokinase-type plasminogen activator (uPA) as an additional circadian clock regulator. Behavioral activity rhythms in tPA-/- mice entrain to a light-dark (LD) cycle and phase shift in response to nocturnal light pulses with no apparent loss in sensitivity. When the LD cycle is inverted, tPA-/- mice take significantly longer to entrain than C57BL/6J wild-type (WT) mice. SCN brain slices from tPA-/- mice exhibit entrained neuronal activity rhythms and phase shift in response to nocturnal glutamate with no change in dose-dependency. Pre-treating slices with the tPA/uPA inhibitor, plasminogen activator inhibitor-1 (PAI-1), inhibits glutamate-induced phase delays in tPA-/- slices. Selective inhibition of uPA with UK122 prevents glutamate-induced phase resetting in tPA-/- but not WT SCN slices. tPA expression is higher at night than the day in WT SCN, while uPA expression remains constant in WT and tPA-/- slices. Casein-plasminogen zymography reveals that neither tPA nor uPA total proteolytic activity is under circadian control in WT or tPA-/- SCN. Finally, tPA-/- SCN tissue has lower mBDNF levels than WT tissue, while UK122 does not affect mBDNF levels in either strain. Together, these results suggest that either tPA or uPA can support photic/glutamatergic phase shifts of the SCN circadian clock, possibly acting through distinct mechanisms.

Sex differences in behavioral circadian rhythms in laboratory rodents.

There is a strong bias in basic research on circadian rhythms toward the use of only male animals in studies. Furthermore, of the studies that use female subjects, many use only females and do not compare results between males and females. This review focuses on behavioral aspects of circadian rhythms that differ between the sexes. Differences exist in the timing of daily onset of activity, responses to both photic and non-photic stimuli, and in changes across the lifespan. These differences may reflect biologically important traits that are ecologically relevant and impact on a variety of responses to behavioral and physiological challenges. Overall, more work needs to be done to investigate differences between males and females as well as differences that are the result of hormonal changes across the lifespan.