Article Text

Download PDFPDF
Limited benefits of ambulance telemetry in delivering early thrombolysis: a randomised controlled trial
  1. M Woollard1,
  2. K Pitt2,
  3. A J Hayward2,
  4. N C Taylor3
  1. 1Faculty of Pre-hospital Care Research Unit, Department of Academic Emergency Medicine, Academic Centre, The James Cook University Hospital, Marton Road, Middlesbrough TS4 3BW, UK
  2. 2Welsh Ambulance Services NHS Trust, Ty Maes Y Gruffydd, Cefn Coed, Swansea SA2 0GP, UK
  3. 3West Wales General Hospital, Glangwili, Carmarthen SA31 2AF, UK
  1. Correspondence to:
 Mr M Woollard
 Faculty of Pre-hospital Care Research Unit, Department of Academic Emergency Medicine, Academic Centre, The James Cook University Hospital, Marton Road, Middlesbrough TS4 3BW, UK;


Objectives: To evaluate the potential of a continuous telemetry system linking rural ambulances to a coronary care unit to reduce call to thrombolysis times.

Methods: This prospective randomised controlled trial recruited patients using the 999 ambulance service in a rural area of the UK with signs or symptoms of coronary heart disease. Subjects were assigned to receive either standard paramedic treatment or transmission of 12 lead ECG, blood pressure, pulse oximetry, and relevant medical history to a general hospital coronary care unit. Cardiology senior house officers then determined each patient’s suitability for pre-hospital thrombolysis time, and transmitted this decision back to the ambulance. This was documented as the potential thrombolysis, although no thrombolytic agents were administered by paramedics. The between groups difference in time to potential thrombolysis (intervention group) and actual thrombolysis (controls) was compared. The proportion of intervention group subjects ultimately receiving thrombolysis in hospital was compared with that recommended for pre-hospital thrombolysis.

Results: The potential reduction in call to treatment time for telemetry patients recommended for pre-hospital thrombolysis was 55 minutes (p = 0.022). Following hospital admission,21/213 of the telemetry patients were thrombolysed (10%, 95% confidence interval (CI) 6% to 15%). Of these patients, 3/21 received a recommendation for thrombolysis in the ambulance (14%, 95% CI 3.1% to 36.3%). The sensitivity and specificity of the telemetry system in detecting patients requiring thrombolysis was 13.6 and 99.5% respectively. Errors were made in the pre-hospital treatment recommendations for two patients.

Conclusions: Continuous telemetry systems may significantly reduce call to treatment times for patients recommended for pre-hospital thrombolysis in a rural setting. However, this benefit must be balanced against the very small proportion of eligible patients identified as suitable for pre-hospital thrombolysis. This limitation may be due to communications problems, the criteria used to identify eligible patients, or the seniority of physicians tasked with making treatment decisions.

  • CCU, coronary care unit
  • SHO, senior house officer
  • Telemetry
  • early thrombolysis
  • myocardial infarction
  • paramedic
  • pre-hospital

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.


  • The study was supported by a small project grant from the Wales Office of Research and Development. Ortivus UK supplied, fitted, and maintained the equipment for this study. A satellite phone and the cost of calls in the latter part of the study were funded by ESYS.

  • Competing interests: there are no competing interests

Linked Articles

  • Primary Survey
    Jonathan Wyatt