Feasibility of prehospital r-TPA therapy in chest pain patients

Ann Emerg Med. 1992 Apr;21(4):379-83. doi: 10.1016/s0196-0644(05)82654-x.

Abstract

Study objective: The purpose of this study was to determine the number of eligible prehospital thrombolytic candidates and to estimate the potential time saved if field thrombolysis had been initiated in a series of prehospital chest pain patients.

Design and setting: Prehospital 12-lead ECGs were obtained by paramedics during initial evaluation of chest pain patients and stored in the computerized ECG. Prehospital 12-lead ECGs, prehospital charts, and hospital charts then were reviewed retrospectively for final hospital diagnosis, prehospital and emergency department times, and historical exclusion criteria for prehospital treatment with recombinant tissue-type plasminogen activator (r-TPA).

Type of participants: One hundred fifty-seven stable adult prehospital patients with a chief complaint of nontraumatic chest pain were enrolled. Six patients were excluded. Two had unretrievable 12-lead ECGs, and four refused paramedic transport and thus provided no further data. There were complete data on 151 patients making up the final study population.

Interventions: Prehospital care was unaltered except for acquisition of 12-lead ECGs. No prehospital thrombolytic therapy was administered during this study.

Measurements and main results: The incidence of r-TPA exclusion criteria was as follows: 45 patients (29%) were 75 years of age or older, 57 (38%) had chest pain for more than six hours, 24 (16%) had hypertension with blood pressure of more than 180/110 mm Hg, and six (4%) had a history of a cerebrovascular accident. The time from paramedic scene arrival to prehospital ECG (8.4 +/- 5.1 minutes) was significantly shorter than the time from ED arrival to ED ECG (24.2 +/- 21.6 minutes, P less than .001). Prehospital ECGs increased paramedic scene time over a retrospective control by 5.2 minutes. Mean time from prehospital ECG to ED ECG (potential time saved) was 50.2 + 22.4 minutes in all patients and 43.4 +/- 7.7 minutes in patients with a final diagnosis of acute myocardial infarction (P = NS). Thirteen of 151 patients (8.6%) had prehospital ECGs diagnostic for acute myocardial infarction; eight of these (5.3% overall) met criteria for prehospital r-TPA therapy.

Conclusion: Prehospital 12-lead ECGs provide an ECG diagnosis 40 to 50 minutes earlier than ED ECGs. However, with current exclusion criteria, the number of prehospital r-TPA candidates is limited.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Chest Pain / drug therapy*
  • Electrocardiography
  • Emergencies
  • Emergency Medical Services / methods*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Myocardial Infarction / diagnosis
  • Myocardial Infarction / drug therapy
  • Retrospective Studies
  • Time Factors
  • Tissue Plasminogen Activator / therapeutic use*

Substances

  • Tissue Plasminogen Activator