Improving apnoeic oxygenation use for rapid sequence intubation in an emergency department

Evidence regarding the efficacy of high-flow nasal cannula (HFNC) oxygenation for preoxygenation and apnoeic oxygenation is conflicting. Our objective is to evaluate whether HFNC oxygenation for preoxygenation and apnoeic oxygenation maintains higher oxygen saturation (SpO2) during rapid sequence intubation (RSI) in ED patients compared to usual care. This was a multicentre, open-label, randomised controlled trial in adult ED patients requiring RSI. Patients were randomly assigned 1:1 to either intervention (HFNC oxygenation at 60L/min) group or control (non-rebreather mask for preoxygenation and nasal prongs of at least 15L/min oxygen flow for apnoeic oxygenation) group. Primary outcome was lowest SpO2 during the first intubation attempt. Secondary outcomes included incidence of SpO2 falling below 90% and safe apnoea time. One hundred and ninety patients were included, with 97 in the intervention and 93 in the control group. Median lowest SpO2 during the first intubation attempt was 100% in both groups. Incidence of SpO2 falling below 90% was lower in the intervention group (15.5%) compared to the control group (22.6%) (adjusted relative risk=0.68, 95% confidence interval [CI] 0.37-1.25). Post hoc quantile regression analysis showed that the first quartile of lowest SpO2 during the first intubation attempt was greater by 5.46% (95% CI 1.48-9.45%, P=0.007) in the intervention group. Use of HFNC for preoxygenation and apnoeic oxygenation, when compared to usual care, did not improve lowest SpO2 during the first intubation attempt but may prolong safe apnoea time.

Rapid sequence intubation (RSI) is a core critical care skill. Emergency medicine trainees are exposed to relatively low numbers of RSIs. We aimed to improve patient outcomes by implementing an RSI checklist, electronic learning and audit, in line with current best evidence. Prospective observational study of RSIs performed in the EDs of two Queensland hospitals between January 2014 and December 2016. Data collected included: first-pass success (FPS), predicted difficulty, indication for intubation, drugs used, positioning, number of attempts, checklist use and complications. Descriptive statistics and multivariable modelling were used to describe differences in FPS, and complications. Six hundred and fifty-five patients underwent RSI with FPS of 86.6%. Complications were reported in 15.9%, mainly hypotension (10.9%) and desaturation (4.0%). FPS improved with bougie use (88.9% vs 73.0% without bougie, P < 0.001) and video-laryngoscopy (88.2% vs 72.9% using standard laryngoscopy, P < 0.001). New desaturation was reduced with apnoeic oxygenation (2.0% vs 22.2%, P < 0.001), bougie use (2.8% vs 8.9%, P < 0.001), checklist use (2.3% vs 22.7%, P < 0.001) and achieving FPS (2.1% vs 16.3%, P < 0.001). Complications were reduced with checklist use (13.3% vs 43.2%, P < 0.001) and apnoeic oxygenation use (3.9% vs 31.1%, P < 0.001). Logistic regression found checklist use was associated with reduced desaturation (OR 0.1, 95% CI 0.04-0.27) and the composite variable of any complication (OR 0.39, 95% CI 0.17-0.89). Implementation of an evidence-based care bundle and audit of practice has created a safe environment for trainees to learn the core critical care skill of RSI. In our setting, checklist use was associated with fewer complications.

We thank Lodenius et al. for their paper on pre-oxygenation for rapid sequence induction (RSI), in which they compared facemask pre-oxygenation with transnasal rapid-insufflation ventilatory exchange (THRIVE) in adult patients 1. Even though peripheral oxygen saturation (SpO2) up to 1 min after intubation did not differ between groups, more patients desaturated below 93% in the facemask group. Could we invite the authors to comment on the points we raise below about their paper? Patel et al. demonstrated that THRIVE is safe during apnoeic oxygenation 2. It is therefore expected that apnoeic oxygenation using THRIVE is superior to no oxygenation during intubation, regardless of the type of pre-oxygenation. There is evidence that apnoeic oxygenation using nasal oxygen flow rates of 2–15 l.min−1 prolongs safe apnoea time 3, 4. It would have been interesting to choose an active comparator (e.g. nasal cannula oxygen at 2–10 l.min−1) instead of no oxygen administration during apnoea to see if THRIVE provides a significant benefit over lower oxygen flow rates, considering the low cost of standard nasal cannula compared with the relatively expensive THRIVE equipment. We note that SpO2 dropped to 71% within 150 s in one patient in the facemask group, but no details on the specific circumstances under which this profound desaturation occurred were provided, and whether not analysing this patient would have changed the results significantly. Once apnoea occurred, anaesthetists waited for a median of 58 s in the facemask group before inserting the laryngoscope (apnoea time – intubation time = time until laryngoscope insertion). In the THRIVE group they started after 68 s. Is there any reason why it took longer in the THRIVE group to insert the laryngoscope during these ‘rapid’ sequence intubations? Although THRIVE might reduce the desaturation risk, the risk of regurgitation and aspiration are still there. The start of apnoea time was assessed differently for the two groups. This needs to be explained to avoid bias. Monitoring of end-tidal CO2 was used in the facemask group to determine if spontaneous breathing was present and the disappearance of end-tidal CO2 was defined as the start of apnoea. In contrast, in the THRIVE group, visual observation of chest movements was used to confirm cessation of spontaneous ventilation. Small respiratory movements are sometimes difficult to observe by eye but easier to detect using ETCO2 traces on the monitor. Could the different methods of assessing the start of apnoea have contributed to the duration of apnoea? Another study has described the potential benefits of THRIVE during RSI 5, but the benefits of THRIVE over low-flow nasal cannula oxygen (as well as any added ventilatory effects) still remain unclear. Finally, we suggest that the authors studied rapid sequence intubation rather than rapid sequence induction, as intubation time was measured rather than induction time. We are aware that in everyday use, the ‘I’ in ‘RSI’ is used interchangeably to mean ‘induction’ or ‘intubation’, but perhaps research needs to standardise the ‘I’ to denote ‘induction’, as originally intended?

Background and Aims:Apnoeic oxygenation, although useful during elective intubations, has not shown consistent beneficial results during emergency intubations in critically ill patients. We aimed to study the effectiveness of adding apnoeic oxygenation to our routine practice of using facemask alone, in emergency laparotomy patients needing rapid sequence induction (RSI), for sustaining partial pressure of oxygen (PaO2).Material and Methods:Seventy-two patients undergoing RSI for emergency laparotomy were randomly allocated to either receive pre-oxygenation with 5 L/min of oxygen (O2) with a facemask (Group-FM) or apnoeic oxygenation with 10 L/min of O2 through a nasal catheter in addition to pre-oxygenation (Group-NC). Apnoea (90 s) was allowed from the removal of the facemask before the resumption of ventilation. Arterial blood gas analysis was done at the baseline, following pre-oxygenation and after 90 s of apnoea to study the PaO2 and partial pressure of carbon dioxide (PaCO2). The circuit O2 concentrations (fraction of inspired [FiO2] and end-tidal [EtO2]) were also noted to ensure a steady state of O2 uptake was reached.Results:The circuit O2 concentrations were 90 ± 4% in group FM and 93 ± 5% in Group-NC. The FiO2-EtO2 difference was 4% in both groups. During the 90 s apnoea following pre-oxygenation, there was a fall in the PaO2 by 38% in Group-FM and 12% in Group-NC (P = 0.000). Increase in PaCO2 was similar in both groups (Group-FM: 44 [range: 32–55] mmHg; Group-NC: 42 [range: 33–54] mmHg, P = 0.809).Conclusion:Apnoeic insufflation of O2 using a nasopharyngeal catheter along with facemask oxygenation is more effective in sustaining PaO2 for 90 s during RSI than facemask-only oxygenation in patients undergoing emergency laparotomy.

Editorial IV: Airway management in the emergency department

Apnoeic oxygenation (ApOx) has been demonstrated to reduce the incidence of desaturation, although evidence of benefit has been conflicting depending on the technique used. The aim of this study was...

380 Emergency Airway Management in Japan: Interim Analysis of a Multi-Center Prospective Observational Study

To describe a simple protocol for ventilator-assisted preoxygenation (VAPOX) prior to rapid sequence intubation in the ED using a Hamilton T1 ventilator in an effort to further reduce the incidence of transient and critical hypoxaemia. Ventilator-assisted preoxygenation includes the following steps; preparation for rapid sequence intubation as per institutional protocols, including departmental checklists. Hamilton T1 ventilator is setup in non-invasive spontaneous/timed mode with settings as described. The patient is optimally positioned and nasal cannula applied with an oxygen flow rate of 15 L/min. A face mask is applied with the jaw pulled forward using a two-handed thenar eminence grip and the ventilator is started. Preoxygenation occurs for 3 min. Drugs including neuromuscular blockers are administered, while the operator ensures the airway remains patent. The ventilator transitions into Pressure Controlled Ventilation once apnoea ensues. Nasal oxygen continues until endotracheal tube is successfully secured. We describe a case series of the first eight consecutive adult patients on who VAPOX was applied. All eight patients were clinically deemed at high risk of oxygen desaturation. No clinically significant hypoxia occurred, and the lowest oxyhaemoglobin desaturation was 92%. Preoxygenation using a ventilator with an open valve system may allow safe combination of non-invasive ventilation, pressure controlled ventilation and apnoeic oxygenation using nasal cannula. VAPOX may be the technique of choice to preoxygenate and apnoeic oxygenate many patients who undergo rapid sequence intubation in the ED equipped with these ventilators.

Objectives & BackgroundThe Emergency Department (ED) is a fertile ground for medical error. In numerous other areas checklists (and the associated cultural changes) have been brought in to reduce error....

BackgroundA quarter of all major airway events occur in Emergency department (ED) or Intensive Care Units (ICU).1 Unfamiliar environment, insufficient equipment and inadequately skilled staff lead to avoidable morbidity and...

Emergency physicians: additional providers of emergency anaesthesia?

BackgroundAlthough rapid sequence intubation (RSI) is the method of choice in emergency department (ED) airway management, data to support the use of RSI remain scarce. We sought to compare the effectiveness of airway management between RSI and non-RSI (intubation with sedative agents only or without medications) in the ED.MethodsSecondary analysis of the data from a multicenter prospective observational registry at 13 Japanese EDs. All non-cardiac-arrest patients who underwent intubation with RSI or non-RSI were included for the analysis. Outcomes of interest were the success rate of intubation and intubation-related complications.ResultsOf 2365 eligible patients, 761 (32%) underwent intubations with RSI and 1,604 (68%) with non-RSI. Intubations with RSI had a higher success rate on the first attempt compared to those with non-RSI (73 vs. 63%; P < 0.0001). By contrast, the complication rates did not differ significantly between RSI and non-RSI groups (12 vs. 13%; P = 0.59). After adjusting for age, sex, estimated weight, principal indication, device, specialties and training level of the intubator, and clustering of patients within EDs, intubation with RSI was associated with a significantly higher success rate on the first attempt (OR, 2.3; 95% CI, 1.8–2.9; P < 0.0001) while that with RSI was not associated with the risk of complications (OR, 0.9; 95% CI, 0.6–1.2; P = 0.31).ConclusionsIn this large multicenter study of ED airway management, we found that intubation with RSI was independently associated with a higher success rate on the first attempt but not with the risk of complications.

To characterize current practice with respect to pediatric emergency airway management using a multicenter data set. A multicenter collaboration was undertaken to gather data prospectively regarding emergency intubation. Analysis of data on adult emergency department (ED) intubations clearly demonstrated that rapid sequence intubation (RSI) was the method used most often. We then conducted an observational study of the prospectively collected database of pediatric ED intubations (EDIs) using the National Emergency Airway Registry Phase One data, gathered in 11 participating EDs over a 16-month time period. A data form completed at the time of EDI enabled analysis of patients' ages, weights, and indications for EDI; personnel; methods employed to facilitate EDI; success rates; and adverse events. Data forms were analyzed regarding the methods of intubation employed, and frequencies, success rates, and adverse event rates among various intubation modalities were compared. Of 1288 EDIs, there were 156 documented pediatric patients. Initial intubation attempts were all oral, including rapid sequence intubation in 81%, without medications (NOM) in 13%, and sedation without neuromuscular blockade (SED) in 6%. Older children and trauma patients were more likely to be intubated with RSI compared to younger children and patients presenting with medical illnesses. Intubation using RSI was more successful on the first attempt (78%) compared with either NOM (47%, < 0.01) or SED (44%, < 0.05), though this finding is likely explainable by the age differences among groups. Intubation was successfully performed by the initial intubator in 85% of RSI, 75% of NOM, and 89% of SED attempts ( = NS for both comparisons vs RSI). Overall, successful intubation occurred in 99% of RSI and 97% of non-RSI intubation attempts ( = NS). Only one of 156 patients required surgical airway management. True complications occurred in 1%, 5%, and 0% of RSI, NOM, and SED attempts, respectively ( = NS for both comparisons vs RSI). The majority of initial intubation attempts were by emergency medicine residents (59%), pediatric emergency medicine fellows (17%), and pediatrics residents (10%). These groups were 77%, 77%, and 50% successful, respectively, on the first laryngoscopy attempt, and 89%, 89%, and 69% successful overall. A large, prospective, multicenter observational study of pediatric EDIs was conducted at university-affiliated EDs. RSI is the method of choice for the majority of pediatric emergency intubations; it is associated with a high success rate and a low rate of serious adverse events. Pediatric intubation as practiced in academic EDs, with most initial attempts by emergency and pediatrics residents and fellows under attending physician supervision, is safe and highly successful.

Introduction: Transnasal humidified rapid-insufflation ventilatory exchange (THRIVE), if used for pre-oxygenation and apnoeic oxygenation, has the propensity to extend the safe apnoea time and thereby decrease the incidence of desaturation during rapid sequence induction (RSI) for emergency surgeries. Hence, we proposed to evaluate the comparative efficacy of pre-oxygenation with the use of conventional facemask breathing versus THRIVE during RSI in patients undergoing general anaesthesia (GA) for emergency surgeries.Materials and methods: Eighty patients undergoing RSI under GA for emergency abdominopelvic surgery were divided randomly into two groups. Patients were preoxygenated for three minutes with 100% oxygen via either a high-flow nasal cannula at a flow of 60 L/minute using THRIVE or a tightly-held, snuggly-fitting facemask at a flow of 12L/minute using a circle system. RSI was administered followed by laryngoscopy and endotracheal intubation. Arterial partial pressure of oxygen (PaO2) measured immediately after successful endotracheal intubation was our primary outcome. The lowest peripheral oxygen saturation (SpO2), apnoea time, number of attempts at laryngoscopy, use of any rescue manoeuvres, and any adverse event were also recorded. Data thus collected were statistically analysed.Results: No statistically significant difference in PaO2 value was observed after successful intubation, lowest SpO2, apnoea time, number of attempts at laryngoscopy, use of any rescue manoeuvres, and adverse event between both the groups (p>0.05).Conclusion: We conclude that though not superior to conventional facemasks, THRIVE is a safe, practicable, and efficient pre-oxygenation tool during RSI of GA for patients undergoing emergency surgeries.

Rapid sequence induction (RSI) in the ICU, emergency department (ED) and operating room (OR) carries the risk of hypoxemia if laryngoscopy is prolonged especially in high-risk patients. Bag and mask pre-oxygenation is normally used to extend the apnoea time; however, arterial desaturation may still rapidly occur. Transnasal humidified rapid insufflation ventilatory exchange (THRIVE) is a new technique that provides modest CPAP during pre-oxygenation and crucially also continuous oxygenation of the pharyngeal space throughout the apnoeic period. In elective surgery, THRIVE provides apnoea times as long as 60 minutes due to apnoeic oxygenation [1]. We report the first implementation of THRIVE with emergency patients into the ICU, ED and OR.