Linda Culley

Incidence of agonal respirations in sudden cardiac arrest

STUDY OBJECTIVE To discover the frequency of agonal respirations in cardiac arrest calls, the ways callers describe them, and discharge rates associated with agonal respirations. DESIGN We reviewed taped recordings of calls reporting cardiac arrests and emergency medical technician and paramedic incident reports for 1991. Arrests after arrival of emergency medical services were excluded. SETTING King County, Washington, excluding the city of Seattle. PARTICIPANTS Four hundred forty-five persons with out-of-hospital cardiac arrests receiving emergency medical services. INTERVENTIONS Telephone CPR, emergency medical technicians-defibrillation, and advanced life support by paramedics. MEASUREMENTS AND MAIN RESULTS Any attempts at breathing described by callers were identified, as well as whether agonal respirations could be heard by dispatcher, emergency medical technicians, or paramedics. Agonal respirations occurred in 40% of 445 out-of-hospital cardiac arrests. Callers described agonal breathing in a variety of ways. Agonal respirations were present in 46% of arrests caused by cardiac etiology compared with 32% in other etiologies (P < .01). Fifty-five percent of witnessed arrests had agonal activity compared with 16% of unwitnessed arrests (P < .001). Agonal respirations occurred in 56% of arrests with a rhythm of ventricular fibrillation compared with 34% of cases with a nonventricular fibrillation rhythm (P < .001). Twenty-seven percent of patients with agonal respirations were discharged alive compared with 9% without them (P < .001). CONCLUSION There is a high incidence of agonal activity associated with out-of-hospital cardiac arrest. Presence of agonal respirations is associated with increased survival. These findings have implications for public CPR training programs and emergency dispatcher telephone CPR programs.

Dispatcher-Assisted Cardiopulmonary Resuscitation Risks for Patients Not in Cardiac Arrest

Background— Dispatcher-assisted cardiopulmonary resuscitation (CPR) instructions can increase bystander CPR and thereby increase the rate of survival from cardiac arrest. The risk of bystander CPR for patients not in arrest is uncertain and has implications for how assertive dispatch is in instructing CPR. We determined the frequency of dispatcher-assisted CPR for patients not in arrest and the frequency and severity of injury related to chest compressions. Methods and Results— The investigation was a prospective cohort study of adult patients not in cardiac arrest for whom dispatchers provided CPR instructions in King County, Washington, between June 1, 2004, and January 31, 2007. The study focused on those who received chest compressions. Information was collected through review of the audio and written dispatch report, written emergency medical services report, hospital record, and telephone survey. Of the 1700 patients for whom dispatcher CPR instructions were initiated, 55% (938 of 1700) were in arrest, 45% (762 of 1700) were not in arrest, and 18% (313 of 1700) were not in arrest and received bystander chest compressions. Of the 247 not in arrest who received chest compressions and had complete outcome ascertainment, 12% (29 of 247) experienced discomfort, and 2% (6 of 247) sustained injuries likely or possibly caused by bystander CPR. Only 2% (5 of 247) suffered a fracture, and no patients suffered visceral organ injury. Conclusions— In this prospective study, the frequency of serious injury related to dispatcher-assisted bystander CPR among nonarrest patients was low. When coupled with the established benefits of bystander CPR among those with arrest, these results support an assertive program of dispatcher-assisted CPR.

Public access defibrillation in out-of-hospital cardiac arrest: a community-based study.

Background—The dissemination and use of automated external defibrillators (AEDs) beyond traditional emergency medical services (EMS) into the community has not been fully evaluated. We evaluated the frequency and outcome of non-EMS AED use in a community experience. Methods and Results—The investigation was a cohort study of out-of-hospital cardiac arrest cases due to underlying heart disease treated by public access defibrillation (PAD) between January 1, 1999, and December 31, 2002, in Seattle and surrounding King County, Washington. Public access defibrillation was defined as out-of-hospital cardiac arrest treated with AED application by persons outside traditional emergency medical services. The EMS of Seattle and King County developed a voluntary Community Responder AED Program and registry of PAD AEDs. During the 4 years, 475 AEDs were placed in a variety of settings, and more than 4000 persons were trained in cardiopulmonary resuscitation and AED operation. A total of 50 cases of out-of-hospital cardiac arrest were treated by PAD before EMS arrival, which represented 1.33% (50/3754) of all EMS-treated cardiac arrests. The proportion treated by PAD AED increased each year, from 0.82% in 1999 to 1.12% in 2000, 1.41% in 2001, and 2.05% in 2002 (P = 0.019, test for trend). Half of the 50 persons treated with PAD survived to hospital discharge, with similar survival for nonmedical settings (45% [14/31]) and out-of-hospital medical settings (58% [11/19]). Conclusions—PAD was involved in only a small but increasing proportion of out-of-hospital cardiac arrests.

Increasing the Efficiency of Emergency Medical Services by Using Criteria Based Dispatch

STUDY OBJECTIVES To determine whether criteria based dispatch (CBD) improved the efficiency of the emergency medical services system. DESIGN A before and after design was used to measure effects of CBD. Data were reviewed from medical reports from January 1986 through June 1992. SETTING King County, Washington, excluding the city of Seattle. PARTICIPANTS Residents who called 911 to report a medical emergency. INTERVENTIONS Emergency medical dispatching (EMD), basic life support (BLS), and advanced life support (ALS). RESULTS Findings show a decrease in ALS responses for two tracer conditions that medical control physicians determined not require ALS intervention. The percentage of febrile seizures in which paramedics responded decreased from 41% to 21% (P < .001). The percentage of cerebrovascular accidents in which paramedics responded decreased from 41% to 28% (P < .001). CBD led to a decrease, from 4.7% to 3.8% (P < .001), in frequency of requests by BLS units for dispatch of ALS units. There was no increase in the time required to dispatch each call. CONCLUSION CBD increased the efficiency of the EMS system by significantly reducing ALS responses to incidents not requiring ALS intervention and reducing requests by BLS units for dispatch of ALS units while maintaining a consistent time from receipt of call to dispatch.

Accuracy of determining cardiac arrest by emergency medical dispatchers

STUDY OBJECTIVE To identify and determine the rates of delivery and performance of telephone CPR in noncardiac arrest incidents. DESIGN We studied prospectively all out-of-hospital cardiac arrest and potential cardiac arrest incidents from July 1 through October 31, 1992. SETTING King County, Washington, excluding the city of Seattle. PARTICIPANTS Persons with cardiac arrest or an initial complaint resembling cardiac arrest who received emergency medical services. INTERVENTIONS Dispatcher-assisted telephone CPR. MEASUREMENTS AND MAIN RESULTS Three hundred fifty-eight incidents of cardiac arrest, respiratory arrest, and potential cardiac arrest were reviewed. Telephone CPR was offered appropriately in 61 of 87 cases (70%) and inappropriately in eight of 154 potential cardiac arrests (5.2%) (95% confidence interval, 1.7%, 8.7%). Ventilation instructions were performed appropriately in 52 of 87 cases (60%) and inappropriately in three of 154 potential cardiac arrests (1.9%) (95% confidence interval, 0%, 4.1%). Chest compressions were performed appropriately in 26 of 68 cardiac arrests (38.2%) and inappropriately in two of 173 potential cardiac arrests (1.2%) (95% confidence interval, 0%, 2.8%). CONCLUSION We found a low rate of performance of telephone CPR in King County for incidents resembling cardiac arrest. This finding suggests that the protocols designed for dispatcher-assisted telephone CPR effectively screen out those incidents that may initially resemble cardiac arrest.

E MERGENCY M EDICAL S ERVICES T ELEPHONE R EFERRAL P ROGRAM : A N A LTERNATIVE A PPROACH TO N ONURGENT 911 C ALLS

Objective. To examine the effects of transferring nonurgent 911 calls to a telephone consulting nurse. It was hypothesized that the telephone referral program would result in fewer basic life support (BLS) responses with no adverse patient outcome or decrease in patient satisfaction. Methods. A two-phased prospective study was conducted in an urban and rural setting with a population of 650,000. During phase I, a BLS unit was dispatched on all calls and a nurse intervention was simulated. During phase II, no BLS unit was dispatched for calls meeting study criteria. Callers were transferred to the nurse, and consulting nurse protocols were used to direct care. Data were collected from dispatch, BLS, nurse, and hospital records and patient self-assessment. Results. During phase I, 38 callers were transferred to the consulting nurse with no nurse intervention. During phase II, 133 cases were transferred to the nurse line. There were no adverse outcomes detected. The nurse recommended home care for 31%, physician referral for 24%, referral back to 911 for 17%, community resource for 11%, and other referral for 17%. Nurses contacted 85 patients for telephone follow-up. Ninety-four percent of the patients reported feeling better, 6% felt the same, and none felt worse. Patients were satisfied with the outcome in 96% of the cases. Conclusion. Transferring 911 calls to a nurse line resulted in fewer BLS responses and no adverse patient outcomes, while maintaining high patient satisfaction. Dispatch criteria correctly identified cases with minimal medical needs. A high percentage of the patients reported feeling better after the intervention. This study has major implications for communities interested in efficient use of emergency medical services resources.

DOES THEEMPEROR OFCPR WEARCLOTHES

The fable about the emperor and his clothes (or lack thereof) is hardly a story of wardrobe malfunction; rather, it applauds the challenge to conventional wisdom. Sometimes, however, conventional wisdom is correct. If, in a retelling of the fable, the emperor really does wear a full set of clothes, then the boy who shouts, ‘‘The Emperor has no clothes!’’ is in the least a nuisance, but at worst an impediment to progress. How does this relate to cardiopulmonary resuscitation (CPR)? Over the last nearly 44 years, conventional wisdom has combined chest compression and mouth-to-mouth ventilation for CPR. The benefit of chest compression for treatment of cardiac arrest was discovered in the late 1950s and published in 1960.1 Investigators initially downplayed the importance of mouth-to-mouth ventilation, believing that chest compression alone would produce enough ventilation. Subsequent investigation by Peter Safar and others demonstrated that chest compression alone did not maintain adequate oxygenation but required mouth-to-mouth ventilation.2 Advocates for chest compression and for mouth-to-mouth ventilation recognized the potential importance of both activities and, hence, conventional CPR was born in late 1960.3 Good evidence supports that conventional CPR improves the likelihood of resuscitation as well as subsequent quality of life among survivors.4,5 Recently, a momentum has arisen to eliminate mouth-to-mouth ventilation. The medical directors of several cities (12 according to a USA Today article6) have changed their dispatcher-assisted telephone CPR protocols to provide chest compressions only. In support of their position, advocates for chest compression alone cite results from a randomized study of dispatcherassisted CPR, findings from animal experiments, and the simpler provision and greater willingness to perform chest compression-alone instruction. Let’s consider each of these assertions. Only one human study has rigorously evaluated the survival effects of chest compression alone versus chest compression plus mouth-tomouth ventilation in a randomized study design.7 In this trial from Seattle, the proportion surviving to hospital discharge was higher with chest compression alone, though the difference was not statistically significant. Indeed, the authors write, ‘‘These data demonstrate that a strategy of dispatcher-instructed chest compression plus mouth-to-mouth ventilation was no better than a strategy of dispatcher-instructed chest compression alone. . ..’’ As the authors note, ‘‘the study EMS system has relatively short response times.’’ In most systems, however, the time between collapse and emergency medical services (EMS) arrival is considerably longer, a situation in which ventilation may become increasingly more important to oxygenate blood and remove carbon dioxide.