High‐flow nasal oxygen vs. standard flow‐rate facemask pre‐oxygenation in pregnant patients: a randomised physiological study

Abstract

High-flow nasal oxygen has been shown to provide effective pre-oxygenation and prolong apnoeic time during intubation attempts in non-pregnant patients. We aimed to compare pre-oxygenation using high-flow nasal oxygen (30-70 l.min À1 oxygen flow) via nasal prongs with standard 15 l.min À1 oxygen breathing via a tightfitting facemask. Forty healthy parturients were randomly allocated to these two groups, and furthermore each patient underwent the selected pre-oxygenation method with both 3-min tidal volume breathing and 30s tidal breathing followed by eight vital capacity breaths. With 3-min tidal volume breathing, the respective estimated marginal means for high-flow nasal oxygen and standard flow rate facemask pre-oxygenation were 87.4% (95% CI 85.5-89.2%) and 91.0% (95%CI 89.3-92.7%), p = 0.02; with eight vital capacity breaths the estimated marginal means were 85.9% (95%CI 84.1-87.7%) and 91.8% (95%CI 90.1-93.4%, p < 0.0001). Furthermore, high-flow nasal oxygen did not reliably achieve a mean end-tidal oxygen concentration ≥ 90% compared with the standard flow rate facemask. In this physiological study, high-flow nasal oxygen pre-oxygenation performed worse than standard flow rate facemask pre-oxygenation in healthy term parturients.

Determining the effective pre‐oxygenation interval in obstetric patients using high‐flow nasal oxygen and standard flow rate facemask: a biased‐coin up–down sequential allocation trial

“…Comfort and acceptability scores were similar between interventions and comparable to our previous study . There were a greater number of parturients who could not complete the assigned time intervals in the high‐flow nasal oxygen and high‐flow nasal oxygen with simple facemask groups compared with standard facemask; however, parturients in the standard facemask group did not have to go beyond three or four minutes.…”

Pre‐oxygenation vs. apnoeic oxygenation in obstetrics

“…We congratulate Shippam et al. on their important contribution to the current discussion on the role of high‐flow nasal oxygenation in obstetric patients . In keeping with previous published work , high‐flow nasal oxygenation did not confer an advantage in pre‐oxygenation in this patient group when compared with more standard techniques.…”

Clinical efficacy of high-flow nasal humidified oxygen therapy in patients with hypoxemia

“…In HFNHO therapy, the required oxygen concentration, flow rate, and temperature can be adjusted according to the respiratory condition of each patient, thus providing individualized treatment[7, 33, 34]. In this study, after HFNHO therapy was conducted in patients with mild hypoxemia after tracheal intubation, the HR and RR of patients in the HFNHO group decreased with time and returned to normal values, and they were significantly lower than those of the control group (P<0.05).…”