Comparison of tissue oxygenation achieved breathing oxygen using different delivery devices and flow rates

Introduction: Divers with suspected decompression illness require high concentration normobaric oxygen (O2) as a treatment priority. There are many different O2 delivery devices, with little published data providing direct comparison of their performance. Aim: To evaluate O2 delivery, using tissue O2 partial pressure (PtcO2), in healthy volunteer scuba divers while breathing O2 using three different commercially available delivery devices. Methods: Twelve divers had PtcO2 measured at six limb sites. Participants breathed O2 from: a demand valve using an intraoral mask with a nose clip (NC); a first aid medical O2 rebreathing system (MORS) with an oronasal mask and with an intraoral mask; and a non-rebreather mask (NRB) at 15 or 10 L·min-1. In-line inspired O2 (FIO2) and nasopharyngeal FIO2 were measured. Participants provided subjective ratings of mask comfort, ease of breathing, and overall ease of use for each device. Results: PtcO2 values and nasopharyngeal FIO2 (median[IQR]) were similar with the demand valve with intraoral mask, MORS with both masks and the NRB at 15 L·min-1. PtcO2 and nasopharyngeal FIO2 values were significantly lower with the NRB at 10 L·min-1. The NRB was rated as the most comfortable to wear, easiest to breathe with, and overall the easiest to use. Conclusion: Of the commonly available devices promoted for O2 delivery to injured divers, similar PtcO2 and nasopharyngeal FIO2 values were obtained with each of the three devices tested: MORS with an oronasal or intraoral mask, demand valve with an intraoral mask and NRB at a flow rate of 15 L·min-1. PtcO2 and nasopharyngeal FIO2 values were significantly lower when the flow rate using the NRB was decreased to 10 L·min-1.

Diving and Hyperbaric Medicine

Diving and Hyperbaric Medicine

50

1833-3516

N/A

1

9