Latency and Loss of Pulse Oximetry Signal with the Use of Digital Probes during Prehospital Rapid-Sequence Intubation

Abstract

Background. Prehospital personnel rely on timely and accurate pulse oximetry data when performing critical skills, such as rapid-sequence intubation (RSI). However, loss of signal may be a frequent occurrence in patients with poor peripheral perfusion. In addition, a delay or latency period in the timeliness of pulse oximetry data may exist with probes placed on the fingers. Objective. To define the incidence of pulse oximetry signal loss or a latent period during prehospital RSI. Methods. Patients with severe traumatic brain injury (TBI) (Glasgow Coma Scale score [[GCS]] 3–8) undergoing prehospital RSI by air medical crews were enrolled. Data from hand-held oximetry–capnometry units were analyzed for either the loss of a pulse oximetry tracing (≥ 30 seconds) during the RSI procedure or the presence of a latent period, defined by the saturation of peripheral oxygen (SpO₂) nadir occurring after intubation in patients undergoing desaturation (SpO₂ ≤ 93%%) during the procedure. Results. A total of 98 of 124 patients (79%%, 95%% confidence interval [[CI]] 71–85%%) had pulse oximetry failure during critical points in the RSI procedure. In the 49 patients with a desaturation during RSI, a latent period was observed in 27 patients (55%%, 95%% CI 41–68%%). Conclusions. A high incidence of pulse oximetry failure was observed with the use of a digital pulse oximetry probe during prehospital RSI. In addition, a latent period appears to exist in the majority of patients undergoing desaturation.

Key words: :

• pulse oximetry
• latency
• rapid-sequence intubation
• air medical
• prehospital