Diurnal, weekly and seasonal variations of chest pain in patients transported by emergency medical services

Hourly-level association between ambient temperature and onset of acute chest pain: a case-crossover study in Foshan, China

Exposure to low and high ambient daily temperature has been associated with cardiovascular diseases. However, the hourly association, which may enable a more precise healthcare response, has rarely been explored. This study conducted a time-stratified case-crossover analysis of emergency patients with acute chest pain at the Chest Pain Center (CPC) in Foshan, China from 2018 to 2023. We employed a conditional logistic regression model coupled with a distributed lag non-linear model (DLNM) to evaluate the hourly exposure-lag-response associations with adjustment for potential confounding factors. A total of 17,634 emergency patients with acute chest pain were recorded in this study. We found that cold exposure was significantly associated with the risk of cardiac chest pain (CCP) onset within 0-144 h prior to onset. The odds ratios (ORs) of CCP onset were 1.793 (95% CI: 1.345, 2.390) for cold air temperature (14.7 ℃) and 1.772 (95% CI: 1.353, 2.320) for cold apparent temperature (13.9 ℃), respectively. Non-optimal temperatures exposure, particularly heat, was associated with an elevated risk of non-cardiac chest pain (NCCP) onset, with the highest cumulative risk occurring at a lag of 72 h, and the corresponding ORs were 2.368 (95% CI: 1.374, 4.082) for air temperature and 2.107 (95% CI: 1.334, 3.327) for apparent temperature. This study reveals the positive association between hourly temperature and the onset of the acute chest pain. These findings highlight the importance of positive measures, such as enhancing timely temperature alert systems and optimizing medical resource allocation.

The Daily Patterns of Emergency Medical Events

This study examines population-level daily patterns of time-stamped emergency medical service (EMS) dispatches to establish their situational predictability. Using visualization, sinusoidal regression, and statistical tests to compare empirical cumulative distributions, we analyzed 311,848,450 emergency medical call records from the US National Emergency Medical Services Information System (NEMSIS) for years 2010 through 2022. The analysis revealed a robust daily pattern in the hourly distribution of distress calls across 33 major categories of medical emergency dispatch types. Sinusoidal regression coefficients for all types were statistically significant, mostly at the p < 0.0001 level. The coefficient of determination ( R 2 ) ranged from 0.84 and 0.99 for all models, with most falling in the 0.94 to 0.99 range. The common sinusoidal pattern, peaking in mid-afternoon, demonstrates that all major categories of medical emergency dispatch types appear to be influenced by an underlying daily rhythm that is aligned with daylight hours and common sleep/wake cycles. A comparison of results with previous landmark studies revealed new and contrasting EMS patterns for several long-established peak occurrence hours-specifically for chest pain, heart problems, stroke, convulsions and seizures, and sudden cardiac arrest/death. Upon closer examination, we also found that heart attacks, diagnosed by paramedics in the field via 12-lead cardiac monitoring, followed the identified common daily pattern of a mid-afternoon peak, departing from prior generally accepted morning tendencies. Extended analysis revealed that the normative pattern prevailed across the NEMSIS data when reorganized to consider monthly, seasonal, daylight-savings versus civil time, and pre-/post-COVID-19 periods. The predictable daily EMS patterns provide impetus for more research that links daily variation with causal risk and protective factors. Our methods are straightforward and presented with detail to provide accessible and replicable implementation for researchers and practitioners.

Variation in Health Care Processes, Quality and Outcomes According to Day and Time of Chest Pain Presentation via Ambulance

BACKGROUND

Previous studies examining temporal variations in cardiovascular care have largely been limited to assessing weekend and after-hours effects. We aimed to determine whether more complex temporal variation patterns might exist in chest pain care.

METHODS

This was a population-based study of consecutive adult patients attended by emergency medical services (EMS) for non-traumatic chest pain without ST elevation in Victoria, Australia between 1 January 2015 and 30 June 2019. Multivariable models were used to assess whether time of day and week stratified into 168 hourly time periods was associated with care processes and outcomes.

RESULTS

There were 196,365 EMS chest pain attendances; mean age 62.4 years (standard deviation [SD] 18.3) and 51% females. Presentations demonstrated a diurnal pattern, a Monday-Sunday gradient (Monday peak) and a reverse weekend effect (lower rates on weekends). Five temporal patterns were observed for care quality and process measures, including a diurnal pattern (longer emergency department [ED] length of stay), an after-hours pattern (lower angiography or transfer for myocardial infarction, pre-hospital aspirin administration), a weekend effect (shorter ED clinician review, shorter EMS off-load time), an afternoon/evening peak period pattern (longer ED clinician review, longer EMS off-load time) and a Monday-Sunday gradient (ED clinician review, EMS offload time). Risk of 30-day mortality was associated with weekend presentation (Odds ratio [OR] 1.15, p=0.001) and morning presentation (OR 1.17, p<0.001) while risk of 30-day EMS reattendance was associated with peak period (OR 1.16, p<0.001) and weekend presentation (OR 1.07, p<0.001).

CONCLUSIONS

Chest pain care demonstrates complex temporal variation beyond the already established weekend and after-hours effect. Such relationships should be considered during resource allocation and quality improvement programs to improve care across all days and times of the week.

Water extract of Notopterygium incisum alleviates cold allodynia in neuropathic pain by regulation of TRPA1

ETHNOPHARMACOLOGICAL RELEVANCE

Neuropathic pain can be debilitating and drastically affects the quality of life of those patients suffering from this condition. The Chinese herb Notopterygium incisum Ting ex H.T. Chang has long been used to disperse "cold". One under examined clinical feature of neuropathic pain is sensitivity to cold. Patients with neuropathic pain or arthritis usually describe a worsening of symptoms during the winter.

AIMS OF THIS STUDY

We proposed to test the hypothesis that Notopterygium incisum has a positive effect on the cold sensitivity found in neuropathic pain.

MATERIALS AND METHODS

In this study, we established chronic constriction injury (CCI) and cisplatin induced neuropathic pain mice models. Behavioral experiments and physiological examination methods were employed to investigate the effect of water extract of Notopterygium incisum (WN) on cold pain.

RESULTS

We found WN reduced cold pain and allyl isothiocyanate (AITC, Transient Receptor Potential A1 (TRPA1 agonist)) induced pain. WN inhibited AITC induced calcium response in HEK 293 cells transfected with TRPA1 and dorsal root ganglion (DRG) neurons. Moreover, we found that oral administration of WN reduced cold allodynia and mechanical allodynia caused by (CCI) and cisplatin induced neuropathic pain. We also observed that oral administration of WN decreased responses to AITC in DRG neurons as well as expression of TRPA1 in the WN treated neuropathic pain model.

CONCLUSIONS

The present study provide evidence that Notopterygium incisum alleviates cold allodynia in CCI and cisplatin induced neuropathic pain mouse models. WN alleviated neuropathic pain induced cold allodynia via directly modulating TRPA1. Our findings identify WN as a promising candidate for treating neuropathic pain that highlights a new mechanism of Notopterygium incisum on 'disperse cold'.

The Circadian Clocks, Oscillations of Pain-Related Mediators, and Pain

The circadian clock is a biochemical oscillator that is synchronized with solar time. Normal circadian rhythms are necessary for many physiological functions. Circadian rhythms have also been linked with many physiological functions, several clinical symptoms, and diseases. Accumulating evidence suggests that the circadian clock appears to modulate the processing of nociceptive information. Many pain conditions display a circadian fluctuation pattern clinically. Thus, the aim of this review is to summarize the existing knowledge about the circadian clocks involved in diurnal rhythms of pain. Possible cellular and molecular mechanisms regarding the connection between the circadian clocks and pain are discussed.

Epidemiological Characteristics and Meteorological Factors of Sudden Death among General Population of Ethnic Chinese in Taiwan: An Eighteen-Year Follow-Up Report in a Community

Background

The epidemiological characteristics of sudden death may vary according to ethnicity and country. This study aimed to analyze the distribution of sudden deaths in Taiwan, as well as their epidemiological characteristics and the associated meteorological factors.

Methods

The Chin-Shan Community Cardiovascular Cohort is a longitudinal study conducted in a community in Taipei County since July 1990. A total of 3,602 individuals aged 35 years and older were included in the study. Sudden deaths were prospectively recorded and analyzed.

Results

Eighty-two (68.3% men) sudden deaths (8.56% of all deaths) were reported from July 1990 to December 2008, of which 87.8% were caused by cardiovascular disease. However, only 36.6% were attributed to coronary artery disease. There was a higher incidence of sudden death in the winter [incidence rate ratio (IRR): 1.91, 95% confidence interval (CI): 1.42-2.56], compared to fall, and the highest peak of sudden death occurred between 16:00-20:00 (IRR: 3.00, 95% CI: 1.72-5.22) compared to 00:00-04:00 as the reference group. Additionally, a relatively higher mean temperature was associated with a lower risk of sudden death (IRR: 0.96, 95% CI: 0.93-0.98). On the other hand, higher humidity (IRR: 1.09, 95% CI: 1.02-1.16) and discomfort index (IRR: 1.03, 95% CI: 1.003-1.05) were associated with increased risks of sudden death.

Conclusions

Meteorological factors and circadian patterns were associated with sudden death among our Taiwanese cohort. Our study findings may support potential protective behavior for sudden death via weather forecasting.

Acute coronary syndrome in a hospital in southern Brazil: peak of hospitalizations on Mondays and severe cases on weekends and at night

INTRODUCTION

Ischemic heart disease is the leading cause of death in Brazil and worldwide. The term acute coronary syndrome (ACS) generically represents the acute myocardial ischemic events. These events are clinically divided into three types: acute myocardial infarction (AMI) with ST-segment elevation, AMI without ST-segment elevation, and unstable angina. Although cardiovascular ischemic events occur acutely, studies describe cyclic patterns of ACS, mainly on circadian and weekly variation.

OBJECTIVE

The aim of this study was to analyze the circadian and weekly variation of hospitalizations for ACS in a hospital in southern Brazil in 2019.

METHODS

Observational, cross-sectional type study. The population was the patients hospitalized at the Nossa Senhora da Conceição Hospital (NSCH) in Tubarão (SC, Brazil) with the international classification of diseases (ICD) code referring to ACS in the year 2019, corresponding to 579 patients.

RESULTS

After applying the exclusion criteria, 512 patients hospitalized for ACS were analyzed, 55.1% were male with a median (p25-p75) age of 62.0 (56.0-69.0) years. The main ICDs of hospitalization were: I20.0 (76.2%), I21.9 (16.6%), I21.3 (3.1%) and the most prevalent comorbidities were high blood pressure (82.6%), diabetes (30.1%) and previous AMI (23.6%). The median (p25-p75) time of admission was 14 h (10-18) h and length of stay was 5 (3-9) days. Death occurred in 18 hospitalizations (3.5%) of cases.

CONCLUSION

We conclude that in the present study there was a peak of hospitalizations for ACS on Mondays, proportionally reducing throughout the week and with a significant decrease on the weekend.

Exploring decision making 'noise' when interpreting the electrocardiogram in the context of cardiac cath lab activation

In this commentary paper, we discuss the use of the electrocardiogram to help clinicians make diagnostic and patient referral decisions in acute care settings. The paper discusses the factors that are likely to contribute to the variability and noise in the clinical decision making process for catheterization lab activation. These factors include the variable competence in reading ECGs, the intra/inter rater reliability, the lack of standard ECG training, the various ECG machine and filter settings, cognitive biases (such as automation bias which is the tendency to agree with the computer-aided diagnosis or AI diagnosis), the order of the information being received, tiredness or decision fatigue as well as ECG artefacts such as the signal noise or lead misplacement. We also discuss potential research questions and tools that could be used to mitigate this 'noise' and improve the quality of ECG based decision making.

"Motorcycle Ambulance" Policy to Promote Health and Sustainable Development in Large Cities

INTRODUCTION

Motorcycles can be considered a new form of smart vehicle when taking into account their small and modern structure and due to the fact that nowadays, they are used in the new role of ambulance to rapidly reach emergency patients in large cities with traffic congestion. However, there is no study regarding the measuring of access time for motorcycle ambulances (motorlances) in large cities of Thailand.

STUDY OBJECTIVE

This study aims to compare access times to patients between motorlances and conventional ambulances, including analysis of the use of automated external defibrillators (AEDs) installed on motorlances to contribute to the sustainable development of public health policies.

METHODS

A cross-sectional study was conducted on all motorlance operations in Emergency Medical Services (EMS) at Srinagarind Hospital, Thailand from January 2019 through December 2020. Data were recorded using a national standard operation record form for Thailand.

RESULTS

Two hundred seventy-one motorlance operations were examined over a two-year period. A total of 52.4% (N = 142) of the patients were male. The average times from dispatch to vehicle (motorlance and traditional ambulance) being en route (activation time) for motorlance and ambulance in afternoon shift were 0.59 minutes and 1.45 minutes, respectively (P = .004). The average motorlance response time in the afternoon shift was 6.12 minutes, and ambulance response time was 9.10 minutes at the same shift. Almost all of the motorlance operations (97.8%) were found to have no access to AED equipment installed in public areas. The average time from dispatch to AED arrival on scene (AED access time) was 5.02 minutes.

CONCLUSION

The response time of motorlances was shorter than a conventional ambulance, and the use of AEDs on a motorlance can increase the chances of survival for patients with cardiac arrest outside the hospital in public places where AEDs are not available.

Suspected Labour as a Reason for Emergency Medical Services Team Interventions in Poland—A Retrospective Analysis

The purpose of this study was to present the characteristics of Emergency Medical Services (EMS) team responses to calls regarding suspected labour in out-of-hospital settings in Poland. We performed a retrospective analysis of EMS team interventions in cases of suspected onset of labour outside a hospital setting. The analysis included 12,816 EMS team responses to calls regarding women in suspected labour in the period between January 2018 and December 2019. The mean age of the patients studied was 28.24 years (SD = 6.47). The majority of patients were at term (76.36%) and in their second pregnancy (29.96%). EMS teams were most often dispatched in the summer (25.95%) and in urban areas (63.26%). Most EMS teams were basic (68.99%) and interventions most often took place between 19:00 and 06:59 (63.14%). Significant differences were observed between preterm and term pregnant women attended by EMS teams in terms of variables such as the age of the patient, number of previous labours, history of miscarriage, presence of vaginal bleeding, time of year, location of call, type and composition of EMS team dispatched, urgency code and time of call, duration of intervention, selected emergency medical procedures performed and test results.

Biological rhythms of fatal myocardial infarction in Greece: an autopsy study

BACKGROUND

Biological rhythms, acting as an endogenous clock, prepare and assist the organism to function optimally during predictable seasonal and daily cycles. Many elements of the cardiovascular system exhibit specific rhythmical patterns. Besides genetic mechanisms, external stimuli may alter biological rhythms.

METHODS

The aim of this study was to investigate the patterns of biological rhythms in patients who suffered a fatal myocardial Infarction (MI), ascertained by macroscopical or histopathological examination. Cases of fatal MI examined during the time 2010-2017 were included in our study sample (827 cases in total). Medical History was also obtained for each case. The assessment of seasonal variation of fatal MI was accomplished by employing three different methods, Rayleigh Uniformity Test, X² Goodness-of-fit test and Edward's Seasonality Test. Statistical significance was defined as a 2-sided p value of <0.05.

RESULTS

Regarding the distribution of total cases, fatal MIs onset occurs more often during winter, with higher incidence in December and January. The weekly distribution of cases seems uniform. The circadian pattern presents higher frequencies of fatal MIs between 08:00 and 12:00 with the acrophase between 11:00 and 12:00. Further analysis was conducted separately, depending on the method of time-of-death reporting.

CONCLUSIONS

Taking under consideration the variation of the occurrence of MI related deaths, in accordance with the respective biological rhythms, public health policies more suitable to the individual requirements of every country's population may be adopted.

Association of Prehospital Oxygen Saturation to Inspired Oxygen Ratio With 1-, 2-, and 7-Day Mortality

IMPORTANCE

The early identification of patients at high risk of clinical deterioration represents one of the greatest challenges for emergency medical services (EMS).

OBJECTIVE

To assess whether use of the ratio of prehospital oxygen saturation measured by pulse oximetry (Spo2) to fraction of inspired oxygen (Fio2) measured during initial contact by EMS with the patient (ie, the first Spo2 to Fio2 ratio) and 5 minutes before the patient's arrival at the hospital (ie, the second Spo2 to Fio2 ratio) can predict the risk of early in-hospital deterioration.

DESIGN, SETTING, AND PARTICIPANTS

A prospective, derivation-validation prognostic cohort study of 3606 adults with acute diseases referred to 5 tertiary care hospitals in Spain was conducted between October 26, 2018, and June 30, 2020. Eligible patients were recruited from among all telephone requests for EMS assistance for adults who were later evacuated with priority in advanced life support units to the referral hospitals during the study period.

MAIN OUTCOMES AND MEASURES

The primary outcome was hospital mortality from any cause within the first, second, third, or seventh day after EMS transport to the hospital. The main measure was the Spo2 to Fio2 ratio.

RESULTS

A total of 3606 participants comprised 2 separate cohorts: the derivation cohort (3081 patients) and the validation cohort (525 patients). The median age was 69 years (interquartile range, 54-81 years), and 2122 patients (58.8%) were men. The overall mortality rate of the patients in the study cohort ranged from 3.6% for 1-day mortality (131 patients) to 7.1% for 7-day mortality (256 patients). The best model performance was for 2-day mortality with the second Spo2 to Fio2 ratio with an area under the curve of 0.890 (95% CI, 0.829-0.950; P < .001), although the other outcomes also presented good results. In addition, a risk-stratification model was generated. The optimal cutoff resulted in the following ranges of Spo2 to Fio2 ratios: 50 to 100 for high risk of mortality, 101 to 426 for intermediate risk, and 427 to 476 for low risk.

CONCLUSIONS AND RELEVANCE

This study suggests that use of the prehospital Spo2 to Fio2 ratio was associated with improved management of patients with acute disease because it accurately predicts short-term mortality.