Preoxygenation with high-flow nasal oxygen versus conventional techniques using anatomical face mask in patients undergoing exploratory laparotomy: A randomised comparative study.

Background and aims

Preoxygenation is crucial during rapid sequence induction, especially in peritonitis patients undergoing exploratory laparotomy who are prone to hypoxaemia. This study compares high-flow nasal oxygen (HFNO) versus facemask for preoxygenation efficacy, laryngoscopy duration, desaturation, arterial blood gases, and patient comfort.

Methods

Sixty consenting, haemodynamically stable patients aged ≥15 years, scheduled for exploratory laparotomy, were randomised into two equal groups receiving preoxygenation using either HFNO at 50 L/min for 5 min or standard anatomical facemask (SMO) at 10 L/min. Arterial blood gas samples were obtained preoperatively, 5 min after preoxygenation, and 1 min following intubation. The primary outcome was partial pressure of arterial oxygen (PaO₂) after 5 min of preoxygenation. Secondary outcomes included partial pressure of arterial carbon dioxide (PaCO₂), peripheral oxygen saturation (SpO₂), laryngoscopy duration, desaturation incidence, patient comfort, and haemodynamic parameters. Statistical analysis was performed using independent t-test, Wilcoxon test, and Chi-square test. P <0.05 was considered statistically significant.

Results

PaO2 5 min after preoxygenation was higher in both groups, the mean (standard deviation) increase, greater in HFNO [376.86 (86.57)] than in SMO group [263.68 (77.39)]. This rise was higher even 1 min after intubation in HFNO group [312.89 (82.87)] versus SMO [215.61 (66.95)]. HFNO group also showed a less incidence of desaturation and a decrease in PaCO2 [31.73 (5.46)] than in SMO group [35.72 (8.11)].

Conclusion

Preoxygenation for 5 min by HFNO is superior to facemask as there is an increase in PaO2, decreased PaCO2, less desaturation, and more comfort to patients undergoing exploratory laparotomy.