Je. Hollander et al., ONLINE TELEMETRY - PROSPECTIVE ASSESSMENT OF ACCURACY IN AN ALL-VOLUNTEER EMERGENCY MEDICAL-SERVICE SYSTEM, Academic emergency medicine, 2(4), 1995, pp. 280-286
Objective: To evaluate the need for on-line telemetry control in an al
l-volunteer, predominantly advanced emergency medical technician (A-EM
T) ambulance system. Methods: Emergency medical service (EMS) advanced
life support (ALS) providers were asked to transmit the ECG rhythms o
f monitored patients over a six-month period in 1993. The ECG rhythm i
nterpretations of volunteer EMS personnel were compared with those of
the on-line medical control physician. All discordant readings were re
viewed by a panel of physicians to decide whether the misdiagnosis wou
ld have resulted in treatment aberrations had transmission been unavai
lable. Results: Patients were monitored and rhythms were transmitted i
n 1,825 cases. 1,642 of 1,825 rhythms were correctly interpreted by th
e EMS providers (90%; 95% CI 89-91%). The accuracy of the EMS provider
s was dependent on the patient's rhythm (chi-square, p < 0.00001), the
chief complaint (chi-square, p = 0.0001), and the provider's level of
training (chi-square, p = 0.02). Correct ECG rhythm interpretations w
ere more common when the out-of-hospital interpretation was sinus rhyt
hm (95%), ventricular fibrillation (87%), paced rhythm (94%), or agona
l rhythm (96%). The EMS providers were frequently incorrect when the o
ut-of-hospital rhythm interpretation was atrial fibrillation/flutter (
71%), supraventricular tachycardia (46%), ventricular tachycardia (59%
), or atrioventricular block (50%). Of the 183 discordant cases, 124 (
68%) involved missing a diagnosis of, or incorrectly diagnosing, atria
l fibrillation/flutter. Review of the discordant readings identified 1
1 cases that could have resulted in treatment errors had the rhythms n
ot been transmitted, one of which might have resulted in an adverse ou
tcome. Conclusions: In this all-volunteer, predominantly A-EMT ALS sys
tem, patients with a field interpretation of a sinus rhythm do not req
uire ECG rhythm transmission. Field interpretations of atrial fibrilla
tion/flutter, supraventricular tachycardia, ventricular tachycardia, a
nd atrioventricular blocks are frequently incorrect and should continu
e to be transmitted.