Maternal morbidity and mortality from airway complications during general anaesthesia for pregnant people having caesarean section remains a significant issue globally. Large databases demonstrate approximately 10 times that of the non-pregnant population. It is likely that a better preoxygenation technique may lead to a reduction in maternal morbidity and mortality from airway complications. High flow humidified nasal oxygen (HFNO) is a new technique that has been studied by the investigators in two previous trials in pregnant people: Firstly, “High Flow Humidified Nasal Preoxygenation in Pregnant Women” (HINOP1) which showed that HFNO was feasible and acceptable in 60 per cent of the cohort. Followed by “High flow humidified nasal oxygen versus face mask oxygen for preoxygenation of pregnant women” (HINOP2) which showed that pregnant people achieved better oxygen levels with the new high flow nasal oxygen.
The third proposed study, HINOP3 will focus on the specific group of high risk pregnant people – those with a high body mass index (BMI) as these people are at particularly high risk of airway complications during general anaesthesia for caesarean section.
It is hoped that this study will successfully demonstrate the advantages of high flow humidified nasal oxygen in pregnant people with high body mass. This could then pave the way for widespread international use of this technique in pregnant people, and an extension of its application for apnoeic oxygenation, the desired result of which would be improving the safety of tracheal intubation in pregnant people with high body mass who are at high risk of oxygen desaturation.
Professor Alicia Dennis
Dr Patrick Tan
The Royal Women’s Hospital, Melbourne.
The project was awarded $A83,985 funding through the ANZCA research grants program for 2023.