Roger Fisher

Kaiser Permanente, San Diego, CA, USA

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Publications (11)34.74 Total impact

  • Article: Electrical and mechanical recovery of cardiac function following out-of-hospital cardiac arrest.
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    ABSTRACT: BACKGROUND: Compression pauses may be particularly harmful following the electrical recovery but prior to the mechanical recovery from cardiopulmonary arrest. METHODS AND RESULTS: A convenience sample of patients with out-of-hospital cardiac arrest (OOHCA) were identified. Data were exported from defibrillators to define compression pauses, electrocardiogram rhythm, PetCO2, and the presence of palpable pulses. Pulse-check episodes were randomly assigned to a derivation set (one-third) and a validation set (two-thirds). Both an unweighted and a weighted receiver-operator curve (ROC) analysis were performed on the derivation set to identify optimal thresholds to predict ROSC using heart rate and PetCO2. A sequential decision guideline was generated to predict the presence of ROSC during compressions and confirm perfusion once compressions were stopped. The ability of this decision guideline to correctly identify pauses in which pulses were and were not palpated was then evaluated. A total of 145 patients with 349 compression pauses were included. The ROC analyses on the derivation set identified an optimal pre-pause heart rate threshold of >40beatsmin(-1) and an optimal PetCO2 threshold of >20mmHg to predict ROSC. A sequential decision guideline was developed using pre-pause heart rate and PetCO2 as well as the PetCO2 pattern during compression pauses to predict and rapidly confirm ROSC. This decision guideline demonstrated excellent predictive ability to identifying compression pauses with and without palpable pulses (positive predictive value 95%, negative predictive value 99%). The mean latency period between recovery of electrical and mechanical cardiac function was 78s (95% CI 36-120s). CONCLUSIONS: Heart rate and PetCO2 can predict ROSC without stopping compressions, and the PetCO2 pattern during compression pauses can rapidly confirm ROSC. Use of a sequential decision guideline using heart rate and PetCO2 may reduce unnecessary compression pauses during critical moments during recovery from cardiopulmonary arrest.
    Resuscitation 09/2012; · 3.60 Impact Factor
  • Article: Pre-hospital electrocardiography by emergency medical personnel: effects on scene and transport times for chest pain and ST-segment elevation myocardial infarction patients.
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    ABSTRACT: This study sought to measure the impact of pre-hospital (PH) electrocardiography (ECG) on scene-to-hospital time for patients with chest pain of cardiac origin and those with ST-segment elevation myocardial infarction (STEMI). Pre-hospital ECG decreases door-to balloon (D2B) time for STEMI patients. However, obtaining a PH ECG might prolong scene time. We investigated the impact of obtaining a PH ECG on both scene and transport times for patients with chest pain suspected of cardiac origin. City of San Diego Emergency Medical System runsheets of patients with chest pain from January 2003 to April 2008 were analyzed. The scene times and transport times were compared before (from January 2003 to December 2005) and after (from January 2006 to April 2008) implementation of the PH ECG. Among patients with a PH ECG, median scene times and transport times were compared in patients with and without STEMI. There were 21,742 patients evaluated for chest pain during the study period. Implementation of PH ECG resulted in minimal increases in median scene time (19 min, 10 s vs. 19 min, 28 s, p = 0.002) and transport time (13 min, 16 s vs. 13 min, 28 s, p = 0.007). However, compared with chest pain patients, in STEMI patients (n = 303), shorter median scene time (17 min, 51 s vs. 19 min, 31 s, p < 0.001), transport time (12 min, 34 s vs. 13 min, 31 s, p = 0.006), and scene-to-hospital time was observed (30 min, 45 s vs. 33 min, 29 s, p < 0.001). Obtaining a PH ECG for patients with chest pain minimally prolongs scene and transport times. Further, for STEMI patients, both scene times and transport times are actually reduced leading to a potential reduction in total ischemic time.
    Journal of the American College of Cardiology 07/2012; 60(9):806-11. · 14.16 Impact Factor
  • Article: Gender differences in scene time, transport time, and total scene to hospital arrival time determined by the use of a prehospital electrocardiogram in patients with complaint of chest pain.
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    ABSTRACT: Recent studies have described a gender bias against women in the setting of acute coronary syndrome (ACS). We sought to measure the impact that a prehospital electrocardiogram (PH ECG) has on prehospital total scene time to hospital arrival time, comparing men and women with the complaint of chest pain (cCP). This study retrospectively analyzed San Diego Emergency Medical Services (EMS) runsheets of patients with cCP before and after implementation of the PH ECG protocol. The average scene time (ST), transport time (TT), and total scene-to-arrival-at-hospital time (STH) were compared. After stratification by gender, times were compared in patients with ST-elevation myocardial infarction (STEMI) to those without STEMI. Of 21,742 EMS activations for patients with cCP, there were no significant differences overall. When stratified by gender, there was a significant reduction of ST (00:19:16 min vs. 00:20:48 min, p<0.001, 95% CI 00:01:17-00:01:48) and STH (00:33:22 min vs. 00:35:44 min, p<0.001, 95% CI 00:01:21-00:02:24) favoring men in cases without STEMI. In cases of STEMI, men had a significant reduction in ST (00:17:27 min vs. 00:20:29 min, p<0.001, 95% CI 00:01:24-00:04:40) and STH (00:30:30 min vs. 00:34:25 min, p<0.01, 95% CI 00:01:23-00:06:26) times compared to women. Prehospital ECG implementation led to no significant differences in pre- and post-implementation times. In cases of STEMI, men had significantly reduced scene time and scene-to-hospital time when compared to women. The precise reason for these disparities remains unknown.
    Journal of Emergency Medicine 02/2012; 43(2):291-7. · 1.31 Impact Factor
  • Article: Secure Data Transfers Sharing patient information in the electronic age.
    Criss Brainard, Roger Fisher
    JEMS Journal of Emergency Medical Services 03/2011; 36(3):74-7.
  • Article: Minimizing pre- and post-defibrillation pauses increases the likelihood of return of spontaneous circulation (ROSC).
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    ABSTRACT: The three-phase model of ventricular fibrillation (VF) arrest suggests a period of compressions to "prime" the heart prior to defibrillation attempts. In addition, post-shock compressions may increase the likelihood of return of spontaneous circulation (ROSC). The optimal intervals for shock delivery following cessation of compressions (pre-shock interval) and resumption of compressions following a shock (post-shock interval) remain unclear. To define optimal pre- and post-defibrillation compression pauses for out-of-hospital cardiac arrest (OOHCA). All patients suffering OOHCA from VF were identified over a 1-month period. Defibrillator data were abstracted and analyzed using the combination of ECG, impedance, and audio recording. Receiver-operator curve (ROC) analysis was used to define the optimal pre- and post-shock compression intervals. Multiple logistic regression analysis was used to quantify the relationship between these intervals and ROSC. Covariates included cumulative number of defibrillation attempts, intubation status, and administration of epinephrine in the immediate pre-shock compression cycle. Cluster adjustment was performed due to the possibility of multiple defibrillation attempts for each patient. A total of 36 patients with 96 defibrillation attempts were included. The ROC analysis identified an optimal pre-shock interval of <3s and an optimal post-shock interval of <6s. Increased likelihood of ROSC was observed with a pre-shock interval <3s (adjusted OR 6.7, 95% CI 2.0-22.3, p=0.002) and a post-shock interval of <6s (adjusted OR 10.7, 95% CI 2.8-41.4, p=0.001). Likelihood of ROSC was substantially increased with the optimization of both pre- and post-shock intervals (adjusted OR 13.1, 95% CI 3.4-49.9, p<0.001). Decreasing pre- and post-shock compression intervals increases the likelihood of ROSC in OOHCA from VF.
    Resuscitation 07/2010; 81(7):822-5. · 3.60 Impact Factor
  • Article: F OLLOW-UP OF E LDERLY P ATIENTS W HO R EFUSE T RANSPORT A FTER A CCESSING 9-1-1
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    ABSTRACT: Objective To obtain medical follow-up and determine reasons why elderly patients access paramedics via 9-1-1 and then refuse transport. Methods. A telephone survey of patients aged 65 years and older who refused transport and signed out against medical advice (AMA) after accessing paramedics via 9-1-1 was performed to obtain information about the patients' experiences, reasons why they refused, medical follow-up, and patient outcomes. Results. One hundred of 121 (83%) patients who were contacted by telephone participated in the survey. Patients stated that financial concerns were a major determinant in refusing to be transported. Overall, 70% of the patients reported receiving follow-up medical care. Care was obtained at an emergency department (ED) via a second 9-1-1 call in 16% of cases, at an ED via private vehicle in 13%, at an urgent care clinic by a private vehicle in 35%, and with a family physician via private car in 38% of cases. Of the patients who obtained follow-up, there was a 32% hospital admission rate, with 39% of those admitted to an intensive care unit setting. Finally, 80% of the sample studied did not speak to a physician online, with 49% stating that they would have changed their minds if a physician had suggested transport. Conclusion. The majority of patients who were 65 years of age and older and refused transport received follow-up care, with a significant number requiring admission to the hospital at the time of their follow-up.
    07/2009; 6(4):391-395.
  • Article: Predictors of intubation success and therapeutic value of paramedic airway management in a large, urban EMS system.
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    ABSTRACT: Endotracheal intubation (ETI) is commonly used by paramedics for definitive airway management. The predictors of success and therapeutic value with regard to oxygenation are not well studied. 1) To explore the relationship between intubation success and perfusion status, Glasgow Coma Scale (GCS) score, and end-tidal carbon dioxide (EtCO2); 2) to describe the incidence of unrecognized esophageal intubations with use of continuous capnometry; and 3) to document the incremental benefit of invasive versus noninvasive airway management techniques in correcting hypoxemia. This was a prospective, observational study conducted in a large urban emergency medical services system. Paramedics completed a telephone debriefing interview with quality assurance personnel following delivery of all patients in whom invasive airway management had been attempted. Continuous capnometry was used for confirmation of tube position in all patients. Descriptive statistics were used to document airway management performance, including first-attempt ETI success, overall ETI success, and Combitube insertion (CTI) success. In addition, the incidence of unrecognized esophageal intubation was recorded. The relationship between intubation success and perfusion status, GCS score, and initial EtCO2 value was explored using logistic regression. Finally, recorded SpO2 values and the incidence of hypoxemia (SpO2 < 90%) at baseline, following noninvasive airway maneuvers, and after invasive airway management were compared for perfusing patients. A total of 703 patients were enrolled over 12 months. First-attempt ETI success was 61%, and overall ETI success was 81%; invasive airway management (ETI or CTI) was unsuccessful in 11% of patients. A single unrecognized esophageal intubation was observed (0.1%). A clear relationship between airway management success and perfusion status, GCS score, and initial EtCO2 value was observed. Only EtCO2 demonstrated an independent association with ETI success after adjusting for the other variables. Significant improvements in mean SpO2 and the incidence of hypoxemia over baseline were observed with both noninvasive and invasive airway management techniques in 168 perfusing patients. A relationship between intubation success and perfusion status, GCS score, and initial EtCO2 value was observed. Capnometry was effective in eliminating unrecognized esophageal intubations. Both noninvasive and invasive airway management strategies were effective in increasing SpO2 values and decreasing the incidence of hypoxemia, with additional benefit observed with invasive airway maneuvers in some patients.
    Prehospital Emergency Care 07/2009; 10(3):356-62. · 1.78 Impact Factor
  • Article: The feasibility of a regional cardiac arrest receiving system.
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    ABSTRACT: Patients suffering out-of-hospital cardiac arrest (OOHCA) are generally transported to the closest ED, presumably to expedite a hospital level of care and improve the chances of return for spontaneous circulation (ROSC) or provide post-resuscitative care for patients with prehospital ROSC. As hospital-based therapies for survivors of OOHCA are identified, such as hypothermia and emergency primary coronary interventions (PCI), certain hospitals may be designated as cardiac arrest receiving facilities. The safety of bypassing non-designated facilities with such a regional system is not known. To explore the potential ED contribution in OOHCA victims without prehospital ROSC and document the relationship between transport time and outcome in patients with prehospital ROSC. This was a prospective, observational study conducted in a large, urban EMS system over an 18-month period. Data were collected using the Utstein template for OOHCA. The incidence of prehospital ROSC was calculated for patients who were declared dead on scene, transported but died in the ED, died in the hospital, and survived to hospital discharge. The relationship between transport time and survival was also explored for patients with prehospital ROSC. A total of 1141 cardiac arrest patients were enrolled over the 18-month period. A strong association between prehospital ROSC and final disposition was observed (chi-square test for trend p<0.001). Only two patients who survived to hospital discharge did not have prehospital ROSC. Mean transport times were not significantly different for patients with prehospital ROSC who were declared dead in the ED (8.3min), died following hospital admission (7.8min), and survived to hospital discharge (8.5min). Outcomes in patients with prehospital ROSC who had shorter (7min or less) versus longer transport times were similar, and receiver-operator curve analysis indicated no predictive ability of transport time with regard to survival to hospital admission (area under the curve=0.52). In this primarily urban EMS system, the vast majority of survivors from OOHCA are resuscitated in the field. A relationship between transport time and survival to hospital admission or discharge was not observed. This supports the feasibility of developing a regional cardiac arrest system with designated receiving facilities.
    Resuscitation 07/2007; 74(1):44-51. · 3.60 Impact Factor
  • Article: The three-phase model of cardiac arrest as applied to ventricular fibrillation in a large, urban emergency medical services system.
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    ABSTRACT: Cardiac arrest is responsible for significant morbidity and mortality, with consistently poor outcomes despite the rapid availability of prehospital personnel for defibrillation attempts in patients with ventricular fibrillation (VF). Recent evidence suggests a period of cardiopulmonary resuscitation (CPR) prior to defibrillation attempts may improve outcomes in patients with moderate time since collapse (4-10 min). To determine cardiac arrest outcomes in our community and explore the relationship between time since collapse, performance of bystander CPR, and survival. Non-traumatic cardiac arrest data were collected prospectively over an 18-month period. Patients were excluded for: age <18 years, a "Do Not Attempt Resuscitation" (DNAR) directive, determination of a non-cardiac etiology for arrest, and an initially recorded rhythm other than VF. Patients were stratified by time since collapse (<4, 4-10, > 10 min, and unknown) and compared with regard to survival and neurological outcome. In addition, patients with and without bystander CPR were compared with regard to survival. : A total of 1141 adult non-traumatic cardiac arrest victims were identified over the 18-month study period. This included 272 patients with VF as the initially recorded rhythm. Of these, 185 had a suspected cardiac etiology for the arrest; survival to hospital discharge was 15% in this group, with 82% of these having a good outcome or only moderate disability. Survival was highest among patients with time since collapse of less than 4 min and decreased with increasing time since collapse. There were no survivors among patients with time since collapse greater than 10 min. Among patients with time since collapse of 4 min or longer, survival was significantly higher with the performance of bystander CPR; there was no survival advantage to bystander CPR among patients with time since collapse less than 4 min. The performance of bystander CPR prior to defibrillation by EMS personnel is associated with improved survival among patients with time since collapse longer than 4 min but not less than 4 min. These data are consistent with the three-phase model of cardiac arrest.
    Resuscitation 04/2005; 64(3):341-6. · 3.60 Impact Factor
  • Article: An evaluation of the risk for latex allergy in prehospital EMS providers.
    Gary M Vilke, Roger Fisher, Theodore C Chan
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    ABSTRACT: Hospital health care providers are increasingly being diagnosed as latex sensitive or allergic. Little is established on incidence or risks to prehospital health care providers. A written survey of EMT-DCs and EMT-Ps was done anonymously using established risk stratification questions to identify factors that indicate higher potential for developing latex allergies. There were 666 surveys distributed with 580 (87%) returned completed. Of the respondents, 533 were male (91%) with 510 (87%) reporting more than 5 years of field experience. Of the survey participants, 435 (75%) were EMT-DC level and 145 (25%) were EMT-P level. We found that latex sensitivities and allergies are present in our population, with an 8% incidence of latex allergies in EMT-DCs and 18% in EMT-Ps. A greater number of respondents report having factors that have been established to be associated with increased risk for latex allergies, indicating the need for more vigilant monitoring for the development of such reactions.
    Journal of Emergency Medicine 06/2002; 22(4):345-8. · 1.31 Impact Factor
  • Article: Follow-up of elderly patients who refuse transport after accessing 9-1-1.
    [show abstract] [hide abstract]
    ABSTRACT: To obtain medical follow-up and determine reasons why elderly patients access paramedics via 9-1-1 and then refuse transport. A telephone survey of patients aged 65 years and older who refused transport and signed out against medical advice (AMA) after accessing paramedics via 9-1-1 was performed to obtain information about the patients' experiences, reasons why they refused, medical follow-up, and patient outcomes. One hundred of 121 (83%) patients who were contacted by telephone participated in the survey. Patients stated that financial concerns were a major determinant in refusing to be transported. Overall, 70% of the patients reported receiving follow-up medical care. Care was obtained at an emergency department (ED) via a second 9-1-1 call in 16% of cases, at an ED via private vehicle in 13%, at an urgent care clinic by a private vehicle in 35%, and with a family physician via private car in 38% of cases. Of the patients who obtained follow-up, there was a 32% hospital admission rate, with 39% of those admitted to an intensive care unit setting. Finally, 80% of the sample studied did not speak to a physician online, with 49% stating that they would have changed their minds if a physician had suggested transport. The majority of patients who were 65 years of age and older and refused transport received follow-up care, with a significant number requiring admission to the hospital at the time of their follow-up.
    Prehospital Emergency Care 6(4):391-5. · 1.78 Impact Factor