一剑科学家让我帮她发到这里....!请大家学习交流吧~~~哈哈哈...
=================================

本文是摘抄AHA2010指南的指导性文件当时发在circulation上的，应该是最权威的。这里面讲得不能再清楚了，说急救接线员在电话上就应该指示打电话求救的人（可能是病人本人或者any打电话进来的人）在等待救援到达期间马上嚼碎服用325毫克阿司匹林非肠溶片一片。

2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science
Part 10: Acute Coronary Syndromes

Robert E. O'Connor, Chair;
William Brady; Steven C. Brooks; Deborah Diercks; Jonathan Egan; Chris Ghaemmaghami; Venu Menon; Brian J. O'Neil;
Andrew H. Travers; Demetris Yannopoulos

Circulation.
2010; 122: S787-S817
doi: 10.1161/CIRCULATIONAHA.110.971028
….
Prehospital Management
Patient and Healthcare Provider Recognition of ACS (Figure 1, Box 1)

Prompt diagnosis and treatment offers the greatest potential benefit for myocardial salvage in the first hours of STEMI; and early, focused management of unstable angina and NSTEMI reduces adverse events and improves outcome.4Thus, it is imperative that healthcare providers recognize patients with potential ACS in order to initiate the evaluation, appropriate triage, and management as expeditiously as possible; in the case of STEMI, this recognition also allows for prompt notification of the receiving hospital and preparation for emergent reperfusion therapy. Potential delays to therapy occur during 3 intervals: from onset of symptoms to patient recognition, during prehospital transport, and during emergency department (ED) evaluation.

Patient-based delay in recognition of ACS and activation of the emergency medical services (EMS) system often constitutes the longest period of delay to treatment.5 With respect to the prehospital recognition of ACS, numerous issues have been identified as independent factors for prehospital treatment delay (ie, symptom-to-door time), including older age,6 racial and ethnic minorities,7,8 female gender,9lower socioeconomic status,10,11 and solitary living arrangements.7,12

Hospital-based delays in ACS recognition range from nonclassical patient presentations and other confounding diagnostic issues to provider misinterpretation of patient data and inefficient in-hospital system of care.9,13–16
Symptoms of ACS may be used in combination with other important information (biomarkers, risk factors, ECG, and other diagnostic tests) in making triage and some treatment decisions in the out-of-hospital and ED settings. The symptoms of AMI may be more intense than angina and most often persist for longer periods of time (eg, longer than 15–20 minutes). The classic symptom associated with ACS is chest discomfort, but symptoms may also include discomfort in other areas of the upper body, shortness of breath, sweating, nausea, vomiting, and dizziness. Most often the patient will note chest or upper body discomfort and dyspnea as the predominant presenting symptoms accompanied by diaphoresis, nausea, vomiting, and dizziness.17–19 Isolated diaphoresis, nausea, vomiting, or dizziness are unusual predominant presenting symptoms.20 Atypical or unusual symptoms are more common in women, the elderly, and diabetic patients.21–23 The physical examination of the patient with ACS is often normal.

Public education campaigns increase patient awareness and knowledge of the symptoms of ACS, yet have only transient effects on time to presentation.24,25 For patients at risk for ACS (and for their families), primary care physicians and other healthcare providers should consider discussing the appropriate use of aspirin and activation of EMS system. Furthermore, an awareness of the location of the nearest hospital that offers 24-hour emergency cardiovascular care can also be included in this discussion. Previous guidelines have recommended that the patient, family member, or companion activate the EMS system rather than call their physician or drive to the hospital if chest discomfort is unimproved or worsening 5 minutes after taking 1 nitroglycerin treatment.2

Half the patients who die of ACS do so before reaching the hospital. VF or pulseless VT is the precipitating cardiac arrest rhythm in most of these deaths,26,27 and it is most likely to develop in the early phase of ACS evolution.28 Communities should develop programs to respond to cardiac emergencies that include the prompt recognition of ACS symptoms by patients and their companions as well as by healthcare and public safety providers and early activation of the EMS system. Additional features of such a program include high-quality CPR for patients in cardiac arrest (see Part 5: “Adult Basic Life Support”) and rapid access to and use of an automated external defibrillator (AED) through community AED programs (see Part 6: “Electrical Therapies”).29 Emergency dispatch center personnel should be educated in the provision of CPR instructions for lay rescuers before the arrival of EMS. EMS providers should be trained to respond to cardiovascular emergencies, including ACS and its acute complications.

Emergency dispatch center personnel can provide instrutctions to the patient or caller before EMS arrival. Because aspirin should be administered as soon as possible after symptom onset to patients with suspected ACS, it is reasonable for EMS dispatchers to instruct patients with no history of aspirin allergy and without signs of active or recent gastrointestinal bleeding to chew an aspirin (160 to 325 mg) while awaiting the arrival of EMS providers (Class IIa, LOE C).30–35
EMS providers should be familiar with the presentation of ACS and trained to determine the time of symptom onset. EMS providers should monitor vital signs and cardiac rhythm and be prepared to provide CPR and defibrillation if needed.
EMS providers administer oxygen during the initial assessment of patients with suspected ACS. However, there is insufficient evidence to support its routine use in uncomplicated ACS. If the patient is dyspneic, hypoxemic, or has obvious signs of heart failure, providers should titrate therapy, based on monitoring of oxyhemoglobin saturation, to ≥94% (Class I, LOE C).36

EMS providers should administer nonenteric aspirin (160 [Class I, LOE B] to 325 mg [Class I, LOE C]). The patient should chew the aspirin tablet to hasten absorption.30,37–39 EMS providers should administer up to 3 nitroglycerin doses (tablets or spray) at intervals of 3 to 5 minutes. Nitrates in all forms are contraindicated in patients with initial systoloic blood pressure <90 mm Hg or ≥30 mm Hg below baseline and in patients with right ventricular infarction.40–42Caution is advised in patients with known inferior wall STEMI, and a right-sided ECG should be performed to evaluate RV infarction. Administer nitrates with extreme caution, if at all, to patients with inferior STEMI and suspected right ventricular (RV) involvement because these patients require adequate RV preload. Nitrates are contraindicated when patients have taken a phosphodiesterase-5 (PDE-5) inhibitor within 24 hours (48 hours for tadalafil).43 Morphine is indicated in STEMI when chest discomfort is unresponsive to nitrates (Class I, LOE C); morphine should be used with caution in unstable angina (UA)/NSTEMI due to an association with increased mortality in a large registry (Class IIa, LOE C).44 The efficacy of other analgesics is unknown.


References used in this updated guidelines providing scientific evidence why prehospital administration of oral aspirin is critical.

30. Freimark D, Matetzky S, Leor J, Boyko V, Barbash IM, Behar S, Hod H. Timing of aspirin administration as a determinant of survival of patients with acute myocardial infarction treated with thrombolysis. Am J Cardiol. 2002;89:381–385.
31. Barbash IM, Freimark D, Gottlieb S, Hod H, Hasin Y, Battler A, Crystal E, Matetzky S, Boyko V, Mandelzweig L, Behar S, Leor J. Outcome of myocardial infarction in patients treated with aspirin is enhanced by pre-hospital dministration. Cardiology. 2002;98:141–147.
32. Randomised trial of intravenous streptokinase, oral aspirin, both, or neither among 17,187 cases of suspected acute myocardial infarction: ISIS-2. ISIS-2 (Second International Study of Infarct Survival) Collaborative Group. Lancet.1988;2():349–360.
33. Casaccia M, Bertello F, De Bernardi A, Sicuro M, Scacciatella P. Prehospital management of acute myocardial infarct in an experimental metropolitan system of medical emergencies [in Italian]. G Ital Cardiol. 1996;26:657–672.
34. Quan D, LoVecchio F, Clark B, Gallagher JV III.. Prehospital use of aspirin rarely is associated with adverse events. Prehosp Disaster Med.2004;19:362–365.
35. Eisenberg MJ, Topol EJ. Prehospital administration of aspirin in patients with unstable angina and acute myocardial infarction. Arch Intern Med.1996;156:1506–1510.