DISPATCHERS VS. MPDS; UNUSUAL DNR ORDERS; `VERTICAL` RESPONSE TIMES

Dispatchers vs. MPDS Protocols
     Clawson J, Olola CH, Heward A, et al. Accuracy of emergency medical dispatchers' subjective ability to identify when higher dispatch levels are warranted over a Medical Priority Dispatch System automated protocol's recommended coding based on paramedic outcome data. Emerg Med J 24(8): 560-3, Aug 2007.

     Abstract: The objective was to establish the accuracy of the emergency medical dispatcher's (EMD's) decisions to override the automated Medical Priority Dispatch System (MPDS) logic-based response code recommendations based on at-scene paramedic-applied transport acuity determinations and cardiac arrest findings. Methods-A retrospective study of a one-year data set from the London Ambulance Service/National Health Service Trust was undertaken. [Authors] compared outcomes of the incidents automatically recommended and accepted as Charlie-level codes to those receiving EMD Delta overrides from the auto-recommended Charlie level. [They] also compared the recommended Delta-level outcomes to those in the higher Echo-override cases. Results-There was no significant association between outcomes and the determinant codes (Delta-override and Charlie-level). Similar patterns were observed between outcomes and Delta-level and Echo-override codes. Conclusion-This study contradicts the belief that EMDs can accurately perceive when a patient or situation requires more resources than the MPDS's structured interrogation process logically indicates. This further strengthens the concept that automated, protocol-based call taking is more accurate and consistent than the subjective, anecdotal or experience-based determinations made by individual EMDs.

     Comment: On one hand, it would seem to make sense that an experienced dispatcher could be better able to determine what resources an individual response might require. On the other hand, protocols such as those here are developed and refined over many years and represent the experience of thousands of like calls. We have learned from other parts of medicine, as well as other industries (e.g., aviation), that strict adherence to protocols works well. This study provides good evidence that structured protocols are a better way to consistently provide the most accurate call priority determination. EMS systems should be using EMD protocol adherence as an indicator in their quality improvement efforts.

Non-standard and Verbal DNR Orders
     Mengual RP, Feldman MJ, Jones GR. Implementation of a novel prehospital advance directive protocol in southeastern Ontario. CJEM 9(4): 250-9, July 2007.

     Abstract: Do Not Resuscitate (DNR) orders are commonly accepted in most healthcare settings, but are less widely recognized in the prehospital setting. [Authors] describe the implementation of and satisfaction with a prehospital DNR protocol that allows paramedics to honor verbal and non-standard written DNR requests. Methods-This prospective observational study reviewed all cardiac arrests in southeastern Ontario between March 1, 2003, and September 30, 2005. Following a verbal or non-standard written DNR request, paramedics completed a questionnaire, and a follow-up structured telephone interview was conducted with surrogate decision makers (SDMs). Results-There were 1,890 cardiac arrests during the study period, of which 86 met inclusion criteria. Paramedic surveys were available for 82 cases (95%), and surrogate decision makers were successfully contacted in 50 (58%) . Two SDMs declined to be interviewed. The mean patient age was 72.7 years (standard deviation 13.8), and 65% were male. Sixty-three DNR requests were verbal (73%), and 23 were written (27%). The mean paramedic comfort was rated 4.9 on a five-point Likert scale, with 5 being "very comfortable" (95% CI, 4.9-5.0). The mean SDM comfort was rated by paramedics as 4.9 (95% CI, 4.8-4.9). SDMs reported comfort in withholding CPR in 47 of 48 cases (98%), and with paramedic care in all cases. One SDM stated that although it was consistent with the patient's wishes, she was uncomfortable having to make the DNR request. Conclusions-Satisfaction with this novel prehospital DNR protocol was uniformly high among paramedic and SDM respondents. It appears that such a protocol is feasible and acceptable for the prehospital setting. [Authors'] conclusions are limited by a small sample size, the lack of a comparison group and limited follow-up.

     Comment: We have all responded to a cardiac arrest call where it was obvious to everyone-EMS personnel as well as family members-that resuscitation was not in the patient's best interest. Unfortunately, patients frequently have not, for a variety of reasons, completed a standard DNR form, and without that form there are medicolegal concerns with not attempting resuscitation. This system may help give us another option: to accept the verbal or non-standard DNR request. In this small study both the paramedics and family members were highly satisfied and not, as many of us fear, upset that the wrong decision was made. This approach is better for the patient, their family and EMS.

"Vertical" Response Intervals in an Urban EMS System
     Silverman RA, Galea S, Blaney S, et al. The "vertical response time": Barriers to ambulance response in an urban area. Acad Emerg Med Jun 29, 2007 [E-pub ahead of print].

     Abstract: Ambulance response time is typically reported as the time interval from call dispatch to arrival on-scene. However, the often unmeasured "vertical response time" from arrival on-scene to arrival at the patient's side may be substantial, particularly in urban areas with high-rise buildings or other barriers to access. Objectives-To measure the time interval from arrival on-scene to [arrival at] the patient in a large metropolitan area and to identify barriers to emergency medical services arrival. Methods-This was a prospective observational study of response times for high-priority call types in the New York City 9-1-1 emergency medical services system. Research assistants riding with paramedics enrolled a convenience sample of calls between 2001-03. Results-A total of 449 paramedic calls were included, with a median time from call dispatch to arrival on-scene of 5.2 minutes. The median on-scene-to-patient-arrival interval was 2.1 minutes, leading to an actual response interval (dispatch to patient) of 7.6 minutes. The median on-scene-to-patient interval was 2.8 minutes for residential buildings, 2.7 minutes for office complexes, 1.3 minutes for private homes (less than four stories) and 0.5 minutes for outdoor calls. Overall, for all calls, the on-scene-to-patient interval accounted for 28% of the actual response interval. When an on-scene escort provided assistance in locating and reaching the patient, the on-scene-to-patient interval decreased from 2.3 to 1.9 minutes. The total dispatch-to-patient-arrival interval was less than 4 minutes in 8.7% of calls, less than 6 minutes in 28.5%, and less than 8 minutes in 55.7%. Conclusions-The time from arrival on-scene to [arrival at] the patient's side is an important component of overall response time in large urban areas, particularly in multistory buildings.

     Comment: The largest urban systems have traditionally been challenged in cardiac resuscitation outcomes, and have typically had worse survival rates than smaller communities. This is one explanation: the large time interval from arrival at the curb outside a building to arrival at the actual patient. The common response-interval endpoint of arrival at the curb was taken from fire response systems and has limited usefulness in measuring EMS response times. Previous authors have pointed out the mostly unmeasured and sometimes very long secondary "vertical" intervals for at least 15 years. An accurate patient contact time is an essential data point for planning and assessing and improving patient care. EMS systems should begin to look at times to arrival at the patient's side, rather than arrival at the curb, to direct their quality improvement efforts.

Angelo Salvucci, Jr., MD, FACEP, is an emergency physician and medical director for Santa Barbara County and Ventura County (CA) EMS Agencies, and chair of the California Commission on EMS.