Survival and variability over time from out of hospital cardiac arrest across large geographically diverse communities participating in the Resuscitation Outcomes Consortium.

BACKGROUND: The Resuscitation Outcomes Consortium (ROC)epidemiological registry (Epistry) provides opportunities to assess trends in out-of-hospital cardiac arrest treatment and outcomes. METHODS: Patient, event, system, treatment, and outcome data from adult (≥18 years) out-of-hospital cardiac arrest (OHCA) from 10 geographically diverse North American ROC sites over four 12-month epochs, from July 1, 2011 to June 30, 2015, were assessed. Descriptive statistics were used to characterize the sample and logistic regression assessed the association of study epoch and key covariates on survival. RESULTS: Overall, 85,553 patients were assessed by Emergency Medical Services (EMS) and 45,516 (53.2%, site range 30.4%-69.9%) had resuscitation attempted by EMS. Patient and event characteristics were consistent except for increases in bystander CPR (41.3%-44.9%) and bystander AED application (3.9%-5.2%). EMS CPR depth and compression fraction increased while pre-shock pause interval decreased. Targeted temperature management was performed in 51.1% of admitted patients and early coronary angiography in 30.2%. Survival to hospital discharge improved (from 10.9% to 11.3% across epochs) with epoch significantly associated with survival (p < 0.001) showing an increasing trend in survival over time. (p = 0.02). Marked site variation in survival persisted within and across epochs (overall site range: 4.2%-19.8%). Patients with an initially shockable rhythm (VT/VF) had an overall survival of 32.2% (site range: 11.9%-47.1%) while survival in bystander witnessed VT/VF was 35.8% (site range: 12.9%-53.1%). CONCLUSIONS: Survival from adult OHCA in multiple large geographically-separate sites improved over the study period. Marked site differences in survival persist and addressing this variation is essential to improve outcomes from OHCA across North America.

Review of prehospital sodium bicarbonate use for cyclic antidepressant overdose.

OBJECTIVE: To describe the clinical presentation of patients with cyclic antidepressant (CA) and use of sodium bicarbonate (NaHCO(3)) in the treatment of this overdose in the prehospital setting. METHODS: A three year retrospective observational review of records was performed using the San Diego County Quality Assurance Network database for prehospital providers. All adult patients who were treated with NaHCO(3) by paramedics for a CA overdose were included. Demographic data, presenting cardiovascular and neurological symptoms, paramedic treatments, and any changes in status were reviewed. RESULTS: Twenty one patients were treated by paramedics with NaHCO(3) for CA overdose. Seventeen patients (80%) presented with mental status changes, including 11 presenting with a GCS<8. Seven of the 21 (33%) presented with a cardiac arrhythmia expected to possibly respond to NaHCO(3) treatment. Seven of the 21 (33%) were hypotensive, and five (24%) patients had reported seizure activity. Only 2 of the 21 patients (10%) treated with NaHCO(3) had recorded improvements after administration of the drug, while the other 19 remained stable without any deterioration. Sixteen of 21 patients (76%) were given NaHCO(3) for indications on standing order, while five patients were treated outside the standing order indications by base physician order with none of the five patients having any change in status ater treatment. CONCLUSIONS: After prehospital NaHCO(3) use in patients with CA overdose, there were no complications reported, two patients improved in status and the others remained unchanged. Base hospital physician orders of NaHCO(3) for indications beyond the standing orders were not associated with changes in patient status.

Electrocardiographic manifestations: pulmonary embolism.

The electrocardiographic findings associated with pulmonary embolism have been well described in the medical literature for over 50 years. These abnormalities include changes in rhythm, QRS axis, and morphology, particularly in the QRS and T waves. Such findings may reflect hemodynamic changes, such as right heart strain, as well as myocardial ischemia associated with the disease. Although certain findings may correlate with the severity of pulmonary embolism, the overall utility of the electrocardiogram is limited due to the variable presence, frequency, and transient nature of most of the abnormalities associated with the disease.

Estimation of pediatric patient weight by EMT-PS.

To determine paramedics' experience, comfort, and accuracy in the estimation of pediatric weights, paramedics were surveyed regarding their experience and training in estimating pediatric weights and then were presented with four children and asked to estimate their weights and to calculate the first round of i.v. epinephrine dose for asystole according to protocol. Twenty paramedics participated, with 55% stating they were uncomfortable on pediatric calls; 15 of 20 (75%) stated they were uncomfortable estimating children's weights. The majority of estimations were within 50% of the actual weights. Based on weight estimations, the epinephrine doses were calculated correctly in 88% of all cases. In 10% of cases, the epinephrine dose was incorrect by a factor of 10 times the appropriate dose. The weight range using the Broselow tape was determined correctly by all participants, with 95% correctly reporting the correct dose of epinephrine. Overall, paramedics were accurate in estimating pediatric weights, and use of the Broselow tape improved the precision of these estimations.

Outcome study of minors after parental refusal of paramedic transport.

OBJECTIVE: Patient refusal of paramedic transport against medical advice (AMA) has significant medical-legal implications. Previous studies have investigated patient outcomes after refusal of transport, but none has focused on these events in minors. This study was performed to evaluate the outcomes of this patient population after refusal of transport as well as the significance of base hospital physician discussion with parents in the decision to refuse transport. METHODS: This was a retrospective telephone follow-up survey involving parents of minors for whom transport was refused after accessing emergency medical services (EMS) via the 911 system. Data were initially obtained from paramedic run records and each family was subsequently contacted by telephone and surveyed with regard to their experiences with the field medics in addition to the medical follow-up sought for their child and patient outcomes. RESULTS: Eighty-nine patients met criteria for survey. Telephone contact was made with 44 parents, of whom 32 (73% of those contacted, 36% overall) participated. Twenty-seven (84%) received medical follow-up, either at an emergency department or in a private physician's office. Most patients (89%) who were evaluated and/or treated by a physician were subsequently released, while three children were admitted to the hospital, all three with respiratory or cardiac chief complaints. CONCLUSIONS: Children whose parents refused EMS transport received medical follow-up in the majority of cases, with a small group requiring admission.

The prehospital electrocardiogram.

Although widely used in Europe, the prehospital 12-lead electrocardiogram (EKG) has seen only limited use in this country. Reported benefits of the 12-lead EKG include shortening the door-to-needle time, accelerating the initiation of reperfusion therapy, and overall improving the prehospital and hospital management and outcome of patients with acute myocardial infarction. The field EKG also provides the basis for prehospital fibrinolysis. Concerns still exist, however, regarding the best means of providing real-time field interpretation of the prehospital EKG and the potential for inappropriate field time delay, triage, and treatment of patients. Moreover, questions remain about the overall clinical and cost benefit of expanding this resource universally. The following article reviews the role of prehospital EKG in caring for patients with acute coronary syndromes.

Exercise-associated hyponatremia in marathon runners: a two-year experience.

This study was conducted to better define the pathophysiology, risk factors, and therapeutic approach to exercise-associated hyponatremia. Medical records from all participants in the 1998 Suzuki Rock 'N' Roll Marathon who presented to 14 Emergency Departments (EDs) were retrospectively reviewed to identify risk factors for the development of hyponatremia. Hyponatremic patients were compared to other runners with regard to race time and to other marathon participants seen in the ED with regard to gender, clinical signs of dehydration, and use of nonsteroidal anti-inflammatory drugs (NSAIDs). An original treatment algorithm incorporating the early use of hypertonic saline (HTS) was evaluated prospectively in our own ED for participants in the 1999 marathon to evaluate improvements in sodium correction rate and incidence of complications. A total of 26 patients from the 1998 and 1999 marathons were hyponatremic [serum sodium (SNa) < or =135 mEq/L] including 15 with severe hyponatremia (SNa < or = 125 mEq/L). Three developed seizures and required intubation and admission to an intensive care unit. Hyponatremic patients were more likely to be female, use NSAIDS, and have slower finishing times. Hyponatremic runners reported drinking "as much as possible" during and after the race and were less likely to have clinical signs of dehydration. An inverse relationship between initial SNa and time of presentation was observed, with late presentation predicting lower SNa values. The use of HTS in selected 1999 patients resulted in faster SNa correction times and fewer complications than observed for 1998 patients. It is concluded that the development of exercise-associated hyponatremia is associated with excessive fluid consumption during and after extreme athletic events. Additional risk factors include female gender, slower race times, and NSAID use. The use of HTS in selected patients seems to be safe and efficacious.

The use of midazolam for prehospital rapid-sequence intubation may be associated with a dose-related increase in hypotension.

OBJECTIVE: To investigate the incidence of hypotension associated with the use of midazolam for prehospital rapid-sequence intubation (RSI). METHODS: A retrospective review was performed using charts from the two aeromedical agencies servicing the authors' region. The RSI protocols used by crews from the northern (north) and the southern (south) parts of the region were identical, with the exception of midazolam dosing. The north crews used 0.1 mg/kg for all patients, while the south crews used 0.1 mg/kg up to a maximum of 5 mg. All patients receiving midazolam for prehospital RSI were pooled, with multiple linear regression used to investigate the relationship between midazolam dose and both hypotension and a decrease in systolic blood pressure (SBP) following RSI. Patients weighing >50 kg and patients with traumatic brain injury (TBI) were evaluated separately to determine differences between north and south with regard to midazolam dosing and incidence of hypotension. Multivariate logistical regression was used to test for these differences and for potential confounders such as age, initial SBP, and Glasgow Coma Scale score (GCS). RESULTS: A total of 219 patients were identified from the north (n = 75) and the south (n = 144). Multiple linear regression revealed a statistically significant relationship between midazolam dose and both hypotension and an SBP decrease following RSI. There was no difference between north and south with regard to age, sex, incidence of TBI, initial SBP, or GCS. In patients >50 kg, those from the north received higher doses of midazolam and had a higher incidence of hypotension than those from the south. This relationship was also present in 184 patients with TBI. CONCLUSION: The use of midazolam with prehospital RSI is associated with a dose-related incidence of hypotension.

Effect of surgical cricothyrotomy on the unstable cervical spine in a cadaver model of intubation.

Cricothyrotomy is indicated for patients who require an immediate airway and in whom orotracheal or nasotracheal intubation is unsuccessful or contraindicated. Cricothyrotomy is considered safe with cervical spine (c-spine) injury; however, the amount of c-spine movement that occurs during the procedure has not been determined. In this experimental study, an established cadaver model of c-spine injury was used to quantify movement during cricothyrotomy. A complete C5--6 transection was performed by using an osteotome on 13 fresh-frozen cadavers. Standard open cricothyrotomy was performed on each cadaver, with c-spine images recorded in real time on fluoroscopy, then transferred to video and Kodachrome still images. Outcome measures included movement across the C5--6 site with regard to angulation expressed in degrees of rotation and linear measures of axial distraction and anterior-posterior (AP) displacement expressed as a proportion of C5 body width. Data were analyzed by using descriptive statistics to determine mean change from baseline in each of three planes of movement. Significance was assumed if 95% confidence intervals did not include zero. A significant amount of movement was observed with regard to AP displacement (6.3% of C5 width) and axial distraction (-4.5% of C5 width, indicating narrowing of the intervertebral space). These correspond to 1--2 mm AP displacement and less than 1 mm axial compression. No significant angular displacement was observed. In conclusion, cricothyrotomy results in a small but significant amount of movement across an unstable c-spine injury in a cadaver model. This degree of movement is less than the threshold for clinical significance.

Emergency department patient knowledge of medications.

Therapeutic decisions made by Emergency Physicians are often influenced by which prescribed medications are being taken by patients. We sought to assess Emergency Department (ED) patients' knowledge of their medications by using a survey. A convenience sample of adult ED patients was surveyed verbally by a research assistant. Two-hundred patients were enrolled. Only 48% of patients could recall or produce a list or the actual bottles of all of their medications, 39% knew the times they take their medications, and only 24% knew all the dosages. Seventeen percent brought a list or the actual medication bottles with them to the ED. Patients who had a primary care physician knew all their medications 51% of the time, compared to 43% who did not have a physician. Fifty-one percent of insured patients compared to 38% of non-insured patients could identify all of their medications. Although knowledge of medications is often critical for decision making in the ED, a significant number of patients are unable to provide this information.

Effects of cervical spine immobilization technique and laryngoscope blade selection on an unstable cervical spine in a cadaver model of intubation.

STUDY OBJECTIVE: Orotracheal intubation (OTI) is commonly used to establish a definitive airway in major trauma victims, with several different cervical spine immobilization techniques and laryngoscope blade types used. This experimental, randomized, crossover trial evaluated the effects of manual in-line stabilization and cervical collar immobilization and 3 different laryngoscope blades on cervical spine movement during OTI in a cadaver model of cervical spine injury. METHODS: A complete C5-C6 transection was performed by using an osteotome on 14 fresh-frozen cadavers. OTI was performed in a randomized crossover fashion by using both immobilization techniques and each of 3 laryngoscope blades: the Miller straight blade, the Macintosh curved blade, and the Corazelli-London-McCoy hinged blade. Intubations were recorded in real time on fluoroscopy and then transferred to video and color still images. Outcome measures included movement across C5-C6 with regard to angulation expressed in degrees of rotation and axial distraction and anteroposterior displacement with values expressed as a proportion of C5 body width. Cormack-Lehane visualization grades were also recorded as a secondary outcome measure. Data were analyzed by using multivariate analysis of variance to test for differences between immobilization techniques and between laryngoscope blades and to detect for interactions. Significance was assumed for P values of less than.05. RESULTS: Manual in-line stabilization resulted in significantly less movement than cervical collar immobilization during OTI with regard to anteroposterior displacement. Use of the Miller straight blade resulted in significantly less movement than each of the other 2 blades with regard to axial distraction. The Cormack-Lehane grade was significantly better with manual in-line stabilization versus cervical collar immobilization; no differences were observed between blades. CONCLUSION: Manual in-line stabilization results in less cervical subluxation and allows better vocal cord visualization during OTI in a cadaver model of cervical spine injury. The Miller laryngoscope blade allowed less axial distraction than the Macintosh or Corzelli-London-McCoy blades. The clinical significance of this degree of movement is unclear.

Rapid sequence intubation in the field versus hospital in trauma patients.

We conducted a retrospective review of all adult trauma patients who underwent prehospital field rapid sequence intubation (RSI) by aeromedical crews from 1988 through 1995 and compared them to all trauma patients who arrived by ground transportation and underwent RSI in the trauma suite from 1992 through 1995 at a University hospital. Of the 47 field RSI patients, 46 (97.9%) were successfully intubated, whereas 263 of the 267 (98.5%) hospital RSI patients were successfully intubated. There were no statistical differences in success rates, number of attempts, or immediate intubation events in the procedure between the two groups. There were no differences in delayed events with the exception of pneumonia, which occurred more frequently in the field RSI group (28% vs. 6%, respectively). We performed a subgroup analysis on isolated head injury patients to evaluate outcome. There was no difference in total hospital days, length of ICU stay, mortality or final disposition in the two head injury groups. Though this study is limited by small sample size, we conclude that field RSI is equally successful and safe as hospital RSI.

Successful prehospital airway management by EMT-Ds using the combitube.

OBJECTIVE: To evaluate the ability to train emergency medical technicians-defibrillation (EMT-Ds) to effectively use the Combitube for intubations in the prehospital environment. METHODS: This was an 18-month prospective field study in which EMT-Ds were trained how and in what situations to use the Combitube. Data were then obtained for all patients in whom Combitube insertion was attempted. Indications for use of the Combitube included: unconsciousness without a purposeful response, absence of the gag reflex, apnea or respiratory rate less than 6 breaths/min, age more than 16 years, and height at least 5 feet tall. Contraindications were: obvious signs of death, intact gag reflex, inability to advance the device due to resistance, or known esophageal pathology. Data were entered prospectively from the San Diego County EMS QANet database for prehospital providers. RESULTS: Twenty-two EMT-D provider agencies, involving approximately 500 EMT-Ds, were included as study participants. Combitube insertions were attempted in 195 prehospital patients in cardiorespiratory arrest, with appropriate indication for Combitube use. An overall successful intubation rate (defined as the ability to successfully ventilate) of 79% was observed. Identical success rates for medical and trauma patients were noted. The device was placed in the esophagus 91% of the time. Resistance during insertion was the major reason for unsuccessful Combitube intubations. An overall hospital admission rate of 19% was observed. No complications were reported. CONCLUSION: EMT-Ds can be trained to use the Combitube as a means of establishing an airway in the prehospital setting. Future studies will need to further evaluate its effect on patient outcome.

Safety and efficacy of the Rapid Four-Step Technique for cricothyrotomy using a Bair Claw.

The Rapid Four-Step Technique (RFST) has been demonstrated to be faster than standard open crico thyrotomy technique, but may have a higher incidence of cricoid injury with tracheal hook traction applied caudad. The "Bair Claw" is a novel device that may help eliminate these complications. This randomized, experimental trial used a fresh-frozen cadaver model of cricothyrotomy to compare speed and safety between RFST using a Bair Claw and standard open technique. Outcome measures included time to definitive airway, size of largest endotracheal (ET) tube able to be passed, and incidence of complications. We observed that RFST using a Bair Claw was significantly faster than standard open technique. There was no significant difference with regard to size of ET tube able to be passed with RFST using a Bair Claw versus standard open technique, and there was no damage to trachea or larynx observed with either technique. We concluded that RFST using a Bair Claw is faster and appears to be equally safe when compared to standard open technique in a fresh-frozen cadaver model of cricothyrotomy. The two techniques were equal with regard to maximal ET tube size.

Spirometry in normal subjects in sitting, prone, and supine positions.

OBJECTIVE: Determine whether pulmonary function testing is affected by patient positioning. METHODS: In a descriptive study with measurements made in a sequential but randomized order at a university-based pulmonary function laboratory, 20 healthy men, ages 18-50 years, were evaluated with spirometric assessment of forced vital capacity (FVC), forced expiratory volume in the first second (FEV1), and maximum voluntary ventilation (MVV) in the sitting, supine, and prone positions. Subjects were excluded for body mass index (BMI) > 30 kg/m2 or abnormal baseline spirometry. RESULTS: Comparing sitting to supine and prone positions, there was a statistically significant decline in the spirometry values (reported as percent of predicted normal +/- standard error of the mean). FVC was 102% +/- 4% while sitting, 95% +/- 4% while supine, and 94% +/- 4% while prone. FEV1 was 104% +/- 3% while sitting, 96% +/- 3% while supine, and 94% +/- 3% while prone. MVV was 115% +/- 4% while sitting, 102% +/- 4% while supine, and 97% +/- 3% prone. CONCLUSION: In healthy men with BMI < 30 kg/m2, changing from the sitting to supine or prone position results in statistically significant change in respiratory pattern. However, all spirometry values in each position were normal by American Thoracic Society definitions.

Use of a complete neurological examination to screen for significant intracranial abnormalities in minor head injury.

Indications for head computed tomography (CT) scans are unclear in patients with nonpenetrating head injury and Glasgow Coma Scale (GCS) scores of 15. We performed a prospective study to determine if significant intracranial injury could be excluded in patients with GCS-15 and a normal complete neurological examination. A prospective trial of clinically sober adult patients with GCS = 15 on emergency department (ED) presentation after closed head injury with loss of consciousness or amnesia was conducted from May 1996 through April 1997. All subjects underwent a standardized neurological examination including mental status evaluation, and assessment of motor, sensory, cerebellar and reflex function before CT scan. During the study period, 58 patients met inclusion criteria. Fifty-five patients (95%) had normal CT scans and 23 (42%) had focal neurological abnormalities. Three patients (5%) had CT scan findings of acute intracranial injury, two of whom had normal neurological examinations. One patient had an acute subdural hematoma requiring emergent surgical decompression; the other had both an epidural hematoma and pneumocephalus that did not require surgery. Significant brain injury and need for CT scanning cannot be excluded in patients with minor head injury despite a GCS = 15 and normal complete neurological examination on presentation.

Comparison of wire-guided cricothyrotomy versus standard surgical cricothyrotomy technique.

We compared a wire-guided cricothyrotomy technique vs. standard surgical cricothyrotomy in terms of accuracy in placement, complications, performance time, incision length, and user preference. We conducted a randomized, crossover controlled trial in which Emergency Medicine (EM) attendings and residents performed cricothyrotomies by both standard and wire-guided techniques (using a commercially available kit) on human cadavers after a 15-min training session. Procedure time, incision length, and physician preference were recorded. Cadavers were inspected for accuracy of placement and complications. Airway placement was accurate in 13 of 15 cases for the standard technique (86.7%), and 14 of 15 cases for the wire-guided technique (93.3%). When comparing wire-guided vs. standard techniques, there were no differences in complication rates or performance times. The wire-guided technique resulted in a significantly smaller mean incision length than the standard technique (0.53 vs. 2.53 cm, respectively, p<0.0001). Overall, 14 of 15 physicians stated that they preferred the wire-guided to the standard technique. Our data suggest that this wire-guided cricothyrotomy technique is as accurate and timely to use as the standard technique and is preferred by our physician operators. In addition, the technique results in a smaller incision on human cadaver models.