Pre-hospital emergency medicine: a spectrum of imaging findings.

The goal of emergency medical services (EMS) is to provide urgent medical care and stabilization prior to patient transport to a healthcare facility for definitive treatment. The number and variety of interventions performed in the field by EMS providers continues to grow as early management of severe injuries and critical illness in the pre-hospital setting has been shown to improve patient outcomes. The sequela of many field interventions, including those associated with airway management, emergent vascular access, cardiopulmonary resuscitation (CPR), patient immobilization, and hemorrhage control may be appreciated on emergency department admission imaging. Attention to these imaging findings is important for the emergency radiologist, who may be the first to identify a malpositioned device or an iatrogenic complication arising from pre-hospital treatment. Recognition of these findings may allow for earlier corrective action to be taken in the acute care setting. This review describes common EMS interventions and their imaging findings.

Elimination of Emergency Department Ambulance Divert during the COVID-19 Pandemic Was Not Associated with an Increase in the Average Number of Ambulance Arrivals per Day.

INTRODUCTION: During the COVID-19 pandemic, ambulance divert in our EMS system reached critical levels. We hypothesized that eliminating ambulance divert would not be associated with an increase in the average number of daily ambulance arrivals. Our study objective was to quantify the EMS and emergency department (ED) effects of eliminating ambulance divert during the COVID-19 pandemic. METHODS: Regional hospital divert data were obtained for the 10-county Twin Cities metro from MNTrac, a state-supported online system designed to allow hospitals to indicate their divert status to EMS. ED metrics are reported for a single Level I trauma center and were obtained by a deidentified data pull from our electronic medical record covering the 12 months prior to the elimination of divert (2021) and the 12 months after divert elimination (2022). The decision to eliminate divert occurred in November 2021, based on data available through October, with an implementation date of January 2022. The primary study outcome was to quantify the effect of the elimination of divert on the number of ambulances arriving per day at the study hospital. RESULTS: Regional utilization of ambulance divert increased steadily by 859% from January to October 2021 when 355 individual divert events occurred, totaling 809 h (34 days). There was no significant difference in the number of ambulances that arrived to the study hospital in 2021 (30,774) vs 2022 (30,421) p = 0.15. As compared to 2021, in 2022 there was no significant increase in mean ambulance arrivals per day (84/day vs 83/day, p = 0.08), time to room Emergency Severity Index level 2 (ESI) patients (28 min vs 28 min, p = 0.90), or time to obtain emergent head CT in acute "code stroke" patients (12 min vs 12 min, p = 0.15). Ambulance turnaround interval in the ED did not appreciably increase (16 min vs 17 min, p = 0.15). CONCLUSION: Elimination of ambulance divert was not associated with increases in the number of mean daily ambulance arrivals or EMS turnaround intervals, delays in ESI 2 patients being placed in beds, or prolonged time to head CT in stroke code patients.

Intraosseous Pressure Monitoring in Healthy Volunteers.

STUDY OBJECTIVE: Invasively monitoring blood pressure through the IO device has not been thoroughly demonstrated. This study attempted to establish baseline values of IO pressure in a healthy human population. METHODS: This was a prospective, healthy volunteer, observational study. Participants had two IO devices placed (humerus and tibia), and participant IO pressures, vital signs, and pain scores were monitored for up to 60 minutes. Participants were contacted at 24-hours and 7 days post-testing to assess for adverse events. Summary statistics were calculated for systolic, diastolic, and mean humeral and tibial IO pressure. The ratio of IO to non-invasive blood pressure was calculated, and Bland Altman plots were created. The slope (linear) of the mean humeral and the tibial IO pressures were also calculated. RESULTS: Fifteen subjects were enrolled between April and July 2015. Fourteen of 15 humeral IOs were placed successfully (93.3%) and all 15 of the tibial IOs were placed successfully. Mean tibial systolic, diastolic, and mean IO pressure were 55.8 ± 27.9, 49.3 ± 27.1, and 48.4 ± 29.4 mm Hg, respectively. Humeral systolic, diastolic, and mean IO pressure were 32.9 ± 16.0, 27.4 ± 15.2, and 24.5 ± 14.3 mm Hg. The mean tibial IO pressure was 52.5% ± 32.0% of external cuff pressure ratio. The mean humeral IO pressure was 26.5% ± 15.2% of the external mean blood pressure. The Bland Altman plots showed an inconsistent relationship between the systolic and diastolic cuff pressure and the IO pressures. We observed a 1% per minute decrease in IO pressure from the initial placement until the final reading. CONCLUSIONS: Intraosseous pressure readings can be obtained in healthy human volunteers. However, absolute IOP values were not consistent between subjects. Future research may determine how IO pressure can be used to guide therapy in ill and injured patients.

Prevalence of Unique Pediatric Pathologies Encountered by Paramedic Students Across Age Groups.

UNLABELLED: Introduction Traditionally, Emergency Medical Services (EMS) educators have divided the pediatric population into age groups to assist in targeting their clinical and didactic curriculum. Currently, the accrediting body for paramedic training programs requires student exposure to pediatric patients based entirely on age without specifying exposure to specific pathologies within each age stratification. Identifying which pathologies are most common within the different pediatric age groups would allow educators to design curriculum targeting the most prevalent pathologies in each age group and incorporating the physiologic and psychological developmental milestones commonly seen at that age. Hypothesis It was hypothesized that there are unique clusterings of pathologies, represented by paramedic student primary impressions, that are found in different age groups which can be used to target provider education. METHODS: This is a retrospective review of prospectively collected data documented by paramedic students in the Fisdap (Field Internship Student Data Acquisition Project; Saint Paul, Minnesota USA) database over a one-year period. For the purposes of this study, pediatric patients were defined arbitrarily as those between the ages of 0-16 years. All paramedic student primary impressions recorded in Fisdap for patients aged 0-16 years were abstracted. Primary impression by age was calculated and graphed. The frequency of primary impression was then assessed for significance of trend by age with an alpha ≤.05 considered significant. RESULTS: The following primary impressions showed clinically and statistically significant variability in prevalence among different pediatric age groups: respiratory distress, medical-other, abdominal pain, seizure, overdose/poisoning, behavioral, and cardiac. In patients less than 13 years old, respiratory and other-medical were the most common two primary impressions and both decreased with age. In patients 5-16 years old, the prevalence of abdominal pain and behavioral/psych increased. Bimodal distributions for overdose were seen with one spike in the toddler and another in the adolescent population. Seizures were most common in the age group associated with febrile seizure. Sepsis was seen most often in the youngest patients and its prevalence decreased with age. CONCLUSION: There are statistically significant variations in the frequency of paramedic student primary impressions as a function of age in the pediatric population. Emphasizing paramedic student exposure to the most common pathologies encountered in each age group, in the context of the psychological and physiological milestones of each age, may improve paramedic student pediatric practice. Ernest EV , Brazelton TB , Carhart ED , Studnek JR , Tritt PL , Philip GA , Burnett AM . Prevalence of unique pediatric pathologies encountered by paramedic students across age groups. Prehosp Disaster Med. 2016; 31(4):386-391.

The association between ketamine given for prehospital chemical restraint with intubation and hospital admission.

INTRODUCTION: Intramuscular ketamine has become increasingly popular for prehospital chemical restraint of severely agitated or violent patients because of its favorable adverse effect profile, rapid onset, and wide therapeutic window. However, there is currently no literature quantifying the need for intubation or hospital admission for these patients once they reach the emergency department. METHODS: Medical records for patients receiving prehospital ketamine who were transported to a single level 1 trauma center were abstracted. Ketamine dose, patient weight, final disposition, and presence of intubation were recorded. Exclusion criteria were missing dose or weight and ketamine given for an indication other than chemical restraint. Statistical analysis was preformed with unadjusted Student t test. Statistical significance was defined as P < .05. RESULTS: A convenience sample of 51 consecutive patients was identified with 2 excluded because of missing data, leaving 49 for analysis. Ketamine dosing ranged from 2.25 to 9.42 mg/kg (mean, 5.26 ± 1.65 mg/kg). Significant differences were noted between those who required intubation (n = 14) and those who did not (n = 35) (6.16 ± 1.62 mg/kg vs 4.90 ± 1.54 mg/kg, P = .02). No patients were intubated prehospital. There was an increased dose in patients admitted to a medical ward (57%, 28/49) that approached statistical significance (5.62 ± 1.80 vs 4.78 ± 1.31, P = .06). CONCLUSION: Intubation was observed in our emergency department in 29% of patients administered intramuscular ketamine for prehospital chemical restraint. There was a positive association between higher ketamine doses and both endotracheal intubation and hospital admission. Future research should aim to define the minimum effective ketamine dose for successful chemical restraint.

Comparison of success rates between two video laryngoscope systems used in a prehospital clinical trial.

OBJECTIVES: The primary aims of this study were to compare paramedic success rates and complications of two different video laryngoscopes in a prehospital clinical study. METHODS: This study was a multi-agency, prospective, non-randomized, cross over clinical trial involving paramedics from four different EMS agencies. Following completion of training sessions, six Storz CMAC™ video laryngoscopes and six King Vision™ (KV) video laryngoscopes were divided between agencies and placed into service for 6 months. Paramedics were instructed to use the video laryngoscope for all patients estimated to be ≥ 18 years old who required advanced airway management per standard operating procedure. After 6 months, the devices were crossed over for the final 6 months of the study period. Data collection was completed using a telephone data collection system with a member of the research team (available 24/7). First attempt success, overall success, and success by attempt, were compared between treatment groups using exact logistic regression adjusted for call type and user experience. RESULTS: Over a 12-month period, 107 patients (66 CMAC, 41 KV) were treated with a study device. The CMAC had a significantly higher likelihood of first attempt success (OR = 1.85; 95% CI 0.74, 4.62; p = 0.188), overall success (OR = 7.37; 95% CI 1.73, 11.1; p = 0.002), and success by attempt (OR = 3.38; 95% CI 1.67, 6.8; p = 0.007) compared to KV. Providers reverted to direct laryngoscopy in 80% (27/34) of the video laryngoscope failure cases, with the remaining patients having their airways successfully managed with a supraglottic airway in 3 cases and bag-valve mask in 4 cases. The provider-reported complications were similar and none were statistically different between treatment groups. Complication rates were not statistically different between devices. CONCLUSION: The CMAC had a higher likelihood of successful intubation compared to the King Vision. Complication rates were not statistically different between groups. Video laryngoscope placement success rates were not higher than our historical direct laryngoscopy success rates.

Use of an intraosseous device for invasive pressure monitoring in the ED.

Venous access is essential to providing emergency care for critically ill or injured patients. Obtaining peripheral or central access can be problematic and time consuming. Intraosseous (IO) fluid administration provides similar flow rates and central circulation times compared to central lines, but use of these devices to monitor blood pressure has not been explored. We report a case of successful IO pressure (IOP) monitoring through an IO during the resuscitation of a 31-year-old male. This is the first report of monitoring IOP in a clinical setting and comparing it to traditional measures of central pressure.

2C or not 2C: phenethylamine designer drug review.

New groups of synthetic "designer drugs" have increased in popularity over the past several years. These products mimic the euphoric effects of other well-known illicit drugs but are advertised as "legal" highs and are sold over the internet, at raves and night clubs, and in head shops. The 2C series drugs are ring-substituted phenethylamines that belong to a group of designer agents similar in structure to 3,4-methylenedioxy-N-methylamphetamine (MDMA, Ecstasy). Understanding the pharmacology and toxicology of these agents is essential in order to provide the best medical care for these patients. This review focuses on the pharmacology, pharmacokinetics, clinical effects, and treatment of 2C drug intoxication based on available published literature. Multiple names under which 2C drugs are sold were identified and tabulated. Common features identified in patients intoxicated with 2Cs included hallucinations, agitation, aggression, violence, dysphoria, hypertension, tachycardia, seizures, and hyperthermia. Patients may exhibit sympathomimetic symptoms or symptoms consistent with serotonin toxicity, but an excited delirium presentation seems to be consistent amongst deaths attributed to 2C drugs; at least five deaths have been reported in the literature in patients intoxicated with 2C drugs. 2C drugs are a group of designer intoxicants, many of which are marketed as legal, but may carry risks that consumers are unaware of. These drugs may be characterized by either serotonergic toxicity or a sympathomimetic toxidrome, but a presentation consistent with excited delirium is consistent amongst the reported 2C-related deaths. Treatment of 2C intoxication is primarily supportive, but immediate action is required in the context of excited delirium, hyperthermia, and seizure activity.

Supraglottic airway device use as a primary airway during rapid sequence intubation.

INTRODUCTION: This study compared first-attempt placement success rates of the King LTS-D as a primary airway for patients requiring medication-assisted airway management (MAAM) against historical controls. SETTING: Rotor-wing division of a single critical care transportation company METHODS: 53 providers (RNs/EMT-P) consented to participation and were trained in the use of the King LTS-D. All patients in need of MAAM per agency treatment guidelines were screened for inclusion and exclusion criteria. After each placement attempt, providers completed data collection via telephone. The primary endpoint was comparison of first-attempt placement success rate between the King LTS-D and historical control endotracheal intubation (ETI) MAAM patients. Overall placement success, time to placement, pre- and post-placement SaO2, ETCO2 at 2 minutes after placement, and complications were also analyzed. RESULTS: 38 patients received rapid sequence intubation with the King LTS-D by 23 of 58 consented providers. First-attempt success rate was 76% (29/38), with an overall success rate of 84% (32/38). The primary endpoint analysis showed no difference in first-attempt success rate between historical control ETI MAAM data and King LTS-D (71% vs 76%; OR = 0.1.34 [95% CI Intubation time to insertion was 26 seconds (IQR = 12-46). Pre- and post-insertion SaO(1)2 values were 88.9 ± 12.6% and 92.1 ± 12.7%, respectively. Mean ETCO2 at 2 minutes after placement was 34.8 ± 4.0. Vomit in the patient's airway was the most frequently reported complication (46%). CONCLUSION: Success rates with the King LTS-D were not significantly different from historical control ETI data. Time to placement was comparable to previous reports.

Longitudinal and regional trends in paramedic student exposure to advanced airway placement: 2001-2011.

OBJECTIVES: The primary aims of this study were to determine whether the frequency of placement, type of advanced airway, and settings of advanced airway placement (clinical vs. field) have changed for paramedic students over the last 11 years, and to describe regional differences regarding the same set of variables. METHODS: This study was a retrospective review of prospectively reported airway procedures documented by paramedic students in Fisdap ( http://www.fisdap.net ). Students were included if they graduated from a paramedic program, had procedure entries verified by a preceptor, and provided consent for research. Exclusion criteria included students who had a total number of airway placements ≥2 standard deviations from the mean or had 0 airway placements recorded, and programs with <10 graduating students total over the study period. Airway device types and educational settings were descriptively compared over the 11-year study period by year and region. RESULTS: A total of 8,934 paramedic student records were reviewed, with 2,811 excluded based on a priori criteria, leaving 6,123 records for analysis. In each year, the median number of airway devices placed per student was greater in the clinical setting. Endotracheal intubation (ETI) was more common than alternative airway placement in both the field and clinical settings. The median number of clinical ETIs per student has remained relatively constant at 7. The median number of field ETIs per student ranged from 0 to 1 over the study period, with a median alternative airway placement rate of 0 for both clinical and field settings. For all regions, the majority of procedures were performed in a clinical environment. The median number of clinical alternative airway device placements was 0 for all regions. The number of clinical ETIs ranged from 5 to 11 per student, with the highest number of ETIs per student in the West North Central and New England regions and the lowest in the West South Central and East South Central regions. CONCLUSION: Paramedic students gain the majority of their advanced airway experience in the clinical setting. ETI remains more common than alternative airway placement, although there is significant geographic variation in the number of ETIs per student. High rates of clinical intubations do not correlate with high rates of field intubations.

Evaluation of the Storz CMAC®, Glidescope® GVL, AirTraq®, King LTS-D™, and direct laryngoscopy in a simulated difficult airway.

OBJECTIVE: The aim of this study was to compare first-attempt and overall success rates and success rates in relation to placement time among 5 different airway management devices: Storz CMAC, Glidescope GVL, AirTraq, King LTS-D, and direct laryngoscopy (DL). METHODS: Emergency medical technician basic (EMT-B), EMT-paramedics (EMT-P), and emergency medicine residents and staff physicians placed each of the 5 devices in a random order into an AirSim (TruCorp, Belfast, UK) part-task training manikin. The difficult airway scenario was created by fixing the manikin head to a stationary object and introducing simulated emesis into the hypopharynx. First-attempt and overall success and success in relation to placement time were compared. Provider feedback about device performance was also evaluated. RESULTS: Ninety-four providers (16 EMT-basics, 54 EMT-paramedics, and 24 emergency department doctors of medicine) consented to participation. First-attempt and overall success rates for DL, King LTS-D, GVL, and CMAC were not statistically different. Compared with DL, the AirTraq was 96% less likely to be placed successfully (odds ratio, 0.04; 95% confidence interval [CI], 0.01-0.14). When time was factored into the model, the odds of successful placement of the King LTS-D were higher compared with DL (hazard ratio [HR], 1.80; 95% CI, 1.34-2.42) and lower for GVL (HR, 0.59; 95% CI, 0.44-0.80) and AirTraq (HR, 0.228; 95% CI, 0.16-0.325). Providers ranked the CMAC first in terms of performance and preference for use in their practice setting. CONCLUSION: Overall success rates for DL, King-LTS-D, and both video laryngoscope systems were not different. When time was factored into the model, the King LTS-D was more likely to be placed successfully.

The emergency department experience with prehospital ketamine: a case series of 13 patients.

BACKGROUND: There are no published reports examining the effects that ketamine administered prior to hospital arrival has on patients after their transfer to the emergency department (ED). OBJECTIVE: In order to better understand the risk-benefit ratio for the prehospital use of ketamine, we examined the ED courses of 13 patients to whom emergency medical services (EMS) had administered ketamine for chemical restraint. METHODS: This project was undertaken as part of our EMS system's continuous quality improvement (CQI) process. Data were collected retrospectively. All patients who were given ketamine by EMS providers under our medical direction were identified by prehospital care report queries. The treating paramedic and emergency physician were provided a CQI form after disposition of the patient from their care. The data were tabulated and descriptive statistics were calculated. RESULTS: Thirteen patients were given ketamine by EMS providers, with 13 of 13 having EMS records and 12 of 13 having ED records available for review. Time from ketamine administration to peak sedation was <5 minutes in 11 patients and 20 minutes for two patients. On emergency physician examination, five of 12 patients had Richmond Agitation Sedation Scale (RASS) scores of -5 (unarousable), one of 12 had a RASS score of -4 (deep sedation), four of 12 had RASS scores of -3 (moderate sedation), and two of 12 had RASS scores of -2 (light sedation). Three patients developed hypoxia, two in the ED and one prior to hospital arrival. Two of these patients required intubation and one was treated with jaw thrust. Indications for intubation were recurrent laryngospasm and intracranial bleeding. One additional patient experienced a single episode of hypersalivation, which was successfully treated with suctioning of the oropharynx. Of the nonintubated patients, three of 10 were diagnosed with an emergence reaction and five of 10 required additional sedation. The primary diagnosis on ED disposition was drug/ethanol intoxication (3), psychosis (4), intracranial bleeding (1), seizure (1), suicidal ideation (1), agitation (1), and altered mental status (1). Five patients were discharged from the ED, seven were admitted (two to the intensive care unit, four to medicine, and one to psychiatry), and one patient's disposition was unknown. CONCLUSIONS: In this series of 13 patients, ketamine administered by EMS produced moderate or deeper sedation. Respiratory complications included hypoxia, laryngospasm, and hypersalivation. Emergence reactions occurred in 30% of nonintubated patients, but they were successfully treated with small doses of benzodiazepines.

Potential negative effects of epinephrine on carotid blood flow and ETCO2 during active compression-decompression CPR utilizing an impedance threshold device.

OBJECTIVES: This study examines the effects of IV epinephrine administration on carotid blood flow (CBF) and end tidal CO(2) (ETCO(2)) production in a swine model of active compression-decompression CPR with an impedance threshold device (ACD-CPR+ITD). METHODS: Six female swine (32 ± 1 kg) were anesthetized, intubated and ventilated. Intracranial, thoracic aorta and right atrial pressures were measured via indwelling catheters. CBF was recorded. ETCO(2), SpO(2) and EKG were monitored. V-fib was induced and went untreated for 6 min. Three minutes each of standard CPR (STD), STD-CPR+impedance threshold device (ITD) and active compression-decompression (ACD)-CPR+ITD were performed. At minute 9 of the resuscitation, 40 µg/kg of IV Epinephrine was administered and ACD-CPR+ITD was continued for 1 min. Statistical analysis was performed with a paired t-test. p values of <0.05 were considered statistically significant and all values are reported in mmHg unless otherwise noted. RESULTS: Aortic pressure, cerebral and coronary perfusion pressures increased from STD

Laryngospasm and hypoxia after intramuscular administration of ketamine to a patient in excited delirium.

An advanced life support emergency medical services (EMS) unit was dispatched with law enforcement to a report of a male patient with a possible overdose and psychiatric emergency. Police restrained the patient and cleared EMS into the scene. The patient was identified as having excited delirium, and ketamine was administered intramuscularly. Sedation was achieved and the patient was transported to the closest hospital. While in the emergency department, the patient developed laryngospasm and hypoxia. The airway obstruction was overcome with bag-valve-mask ventilation. Several minutes later, a second episode of laryngospasm occurred, which again responded to positive-pressure ventilation. At this point the airway was secured with an endotracheal tube. The patient was uneventfully extubated several hours later. This is the first report of laryngospam and hypoxia associated with prehospital administration of intramuscular ketamine to a patient with excited delirium.

Laboratory-confirmed gonorrhea and/or chlamydia rates in clinically diagnosed pelvic inflammatory disease and cervicitis.

OBJECTIVE: The aim of this study was to determine the rates of laboratory confirmed gonorrhea (GC) and chlamydia (CT) in emergency department (ED) patients with pelvic inflammatory disease (PID) and cervicitis who were diagnosed clinically and treated empirically. A secondary goal examines which clinical criteria were present in patients with PID testing positive for GC/CT. METHODS: We conducted a retrospective chart review of all ED patents diagnosed with PID or cervicitis during a 40-month period (January 2007-March 2010). Charts were reviewed for laboratory-confirmed GC or CT. For patients with positive GC or CT studies, the presence of key clinical criteria used in the diagnosis of PID was tallied. RESULTS: A total of 1469 patients were diagnosed with cervicitis and 343 with PID. Of these patients, 27 (1.8%) of 1469 and 15 (4.4%) of 343 were GC positive, and 136 (9.3%) of 1469 and 34 (10%) of 343 were CT positive. Twenty-six cervicitis (1.8%) and 9 PID (2.6%) patients were positive for both infections. One hundred eighty-nine cervicitis (13%) and 58 PID (17%) patients were positive for at least 1 sexually transmitted infection. Of the 58 patients with PID with laboratory-confirmed GC/CT, the following clinical criteria were present: abdominal pain, 58 of 58; abdominal tenderness, 50 of 58; cervical discharge, 47 of 58; cervical motion tenderness, 46 of 58; adnexal tenderness, 32 of 58; vaginal bleeding, 8 of 58; and fever, 2 of 58. Ultrasound was preformed in 27 (47%) of 58 GC/CT-positive patients with PID, with findings suggestive of PID in 12 (44%) of 27 ultrasounds. One hundred percent of abnormal ultrasounds were associated with positive GC and/or CT results. CONCLUSION: There is a generally low prevalence of GC and CT in this patient population diagnosed with cervicitis or PID. There is a very low prevalence of coinfection.