ABSTRACT
OBJECTIVE: This study aimed to determine if pulse oximetry could reliably be used after immersion in water, and if so, which of the finger, earlobe or nose most reliably produced a functional waveform. METHOD: Pulse oximetry data was recorded from the ear, nose and finger before and after 30 min of immersion in water. The primary outcome was the ability to measure pulse oximetry at any of the sites. RESULTS: A total of 119 participants were enrolled (with a median age of 16 years, 55% male). A useful pulse oximetry waveform was obtained after immersion from at least one of the measurement sites in 118 (99.2%) participants. Waveforms were usable after immersion in 96% of participants at the nostril, compared to 92% at the finger, and 41% at the ear lobe. The likelihood of success at the ear was significantly lower than either the finger or the nose (41% vs 92% and 96% respectively, p < 0.0001 for both comparisons). The finger and nostril were similar. Oxygen saturations were not significantly different after immersion at the nostril (100% vs 100%, p = 0.537) and finger (100% vs 100%, p = 0.032) sites but were different at the ear (100% vs 96%, p < 0.0001). CONCLUSION: This study demonstrates that pulse oximetry is feasible and reliable in a large cohort of participants who have been immersed in water for 30 min. The results support the nostril as the most reliable location. Only pulse oximeters registered for clinical use should be employed for patient care.
ABSTRACT
OBJECTIVES: Lifesavers in Australia are taught to use pocket mask (PM) rescue breathing and bag valve mask (BVM) ventilation, despite evidence that first responders might struggle with these devices. Novices have successfully used the Laryngeal Mask Airway (LMA) Supreme and iGel devices previously, but there has been no previous comparison of the ability to train lifesavers to use the supraglottic airways compared to standard techniques for cardiac arrest ventilation. METHODS: The study is a prospective educational intervention whereby 113 lifesavers were trained to use the LMA and iGel supraglottic airways. Comparisons were made to standard devices on plastic manikins. Successful ventilation was defined as achieving visible chest rise. RESULTS: The median time to first effective ventilation was similar between the PM (16 s, 95% confidence interval 16-17 s), BVM (17 s, 16-17 s) and iGel devices (18 s, 16-20 s), but longer for the LMA (36 s, 33-38 s). The iGel frequently failed to achieve ventilation (10%) compared with the PM (1%, P < 0.01) and LMA (3%, P < 0.01) but was not worse than the BVM (3%, P < 0.57). Hands-off time was similar between the BVM, LMA and iGel (10 s for each device), but worse for the PM (13 s, P = 0.001). CONCLUSION: Lifesavers using the PM and BVM perform ventilation for cardiopulmonary resuscitation well. There appears to be a limited role for supraglottic airway devices because of limitations in terms of time to first effective ventilation and reliability. Clinical validation of manikin data with live resuscitation performance is required.
