Effectiveness of transnasal humidified rapid-insufflation ventilatory exchange versus traditional preoxygenation followed by apnoeic oxygenation in delaying desaturation during apnoea: A preliminary study

Abstract

Background and Aims:Transnasal humidified rapid-insufflation ventilatory exchange (THRIVE) during apnoea has shown to delay desaturation. The primary objective was to compare time to desaturate to <90% during apnoea with THRIVE versus traditional preoxygenation followed by apnoeic oxygenation.Methods:This prospective, randomised, single-blinded study was conducted in 10 adult patients presenting for direct laryngoscopy under general anaesthesia without endotracheal intubation. Group P patients were preoxygenated with 100% oxygen, and in Group H, high-flow humidified oxygen was delivered using nasal cannula for 3 min. After induction and neuromuscular blockade, time to desaturate to 90%, while receiving apnoeic oxygenation, was noted. Chi-square test and Mann–Whitney tests were used.Results:Group H had a significantly longer apnoea time as compared to Group P (796.00 ± 43.36 vs. 444.00 ± 52.56 s). All patients in Group H continued to have nearly 100% saturation even at 12 min of apnoea. However, in Group P, 80% of patients desaturated to <90% after 6 min of apnoea. Baseline blood gases, that following preoxygenation and at 3 min of apnoea time were comparable in both groups. At 6 min, Group H had a significantly higher PaO2 (295.20 ± 122.26 vs. 135.00 ± 116.78) and PaCO2 (69.46 ± 7.15 vs. 59.00 ± 4.64). Group H continued to have a PaO2 of >200 mmHg even at 12 min of apnoea with a significant rise in PaCO2 along with fall in pH after 6 min.Conclusion:During apnoeic periods time to desaturate to <90% was significantly prolonged with use of THRIVE.

Ease and comfort of pre‐oxygenation with high‐flow nasal oxygen cannulae vs. facemask: a randomised controlled trial

“…The results of previous studies have been mixed in respect of physiological endpoints of this type [14][15][16][17][18][19][20][21][22][23][24]26]. This probably reflects differences in patient groups, in the technicalities of how HFNO was administered and in how the data were obtained.…”

“…Studies of pre-oxygenation with HFNO have had mixed results [13][14][15][16][17][18][19][20][21][22][23]. Technicalities matter: in particular, a closed mouth appears to be important when pre-oxygenating a patient with HFNO [15,17].…”

“…Also, it is difficult to measure F ET O 2 with HFNO [15]. Nevertheless, support has emerged for the potential of HFNO to extend safe apnoeic time through peroxygenation [13–16, 18, 19, 22, 23]. Safe apnoeic time is arguably more relevant to patient safety than F ET O 2 at the end of pre‐oxygenation [12, 15].…”

Supraglottic jet oxygenation and ventilation reduces desaturation during bronchoscopy under moderate to deep sedation with propofol and remifentanil

“… 8 Furthermore, studies have indicated that HFNO results in the accumulation CO 2 because of insufficient ventilation. 13 , 14 …”

Comparison of High-flow Nasal Cannula (HFNC) and Conventional Oxygen Therapy in Obese Patients Undergoing Cardiac Surgery: A Systematic Review and Meta-analysis

“…High-flow nasal cannula (HFNC) provides high-flow (8-80 l/min) inhalation gas with adjustable and relatively constant oxygen concentration (21%~100%), temperature (31-37℃) and humidity (5,6). Compared with conventional oxygenation methods, the advantage of HFNC is that the continuous positive airway pressure (CPAP) can cause mild lung recruitment (7,8), thus, it can reduce the ventilation dead space to improve the oxygenation of critically ill patients and improve patient comfort (9)(10)(11). In addition, some features of HFNC, such as increasing FRC and endexpiratory lung volume (EELV), can improve the oxygenation status of obese patients (12,13).…”