Are «off hours» intubations a risk factor for complications during intubation? A prospective, observational study

Impact of Universal Use of the McGrath Videolaryngoscope as a Device for All Intubations in the Cardiac Operating Room. A Prospective Before-After VIDEOLAR-CAR Study

OBJECTIVE

Tracheal intubation in cardiac surgery patients has a higher incidence of difficult laryngoscopic views compared with patients undergoing other types of surgery. The authors hypothesized that using the McGrath Mac videolaryngoscope as the first intubation option for cardiac surgery patients improves the percentage of patients with "easy intubation" compared with using a direct Macintosh laryngoscope.

DESIGN

A prospective, observational, before-after study.

SETTING

At a tertiary-care hospital.

PARTICIPANTS

One thousand one hundred nine patients undergoing cardiac surgery.

INTERVENTION

Consecutive patients undergoing cardiac surgery were intubated using, as the first option, a Macintosh laryngoscope (preinterventional phase) or a McGrath Mac videolaryngoscope (interventional phase).

MEASUREMENTS AND MAIN RESULTS

The main objective was to assess whether the use of the McGrath videolaryngoscope, as the first intubation option, improves the percentage of patients with "easy intubation," defined as successful intubation on the first attempt, modified Cormack-Lehane grades of I or IIa, and the absence of the need for adjuvant airway devices. A total of 1,109 patients were included, 801 in the noninterventional phase and 308 in the interventional phase. The incidence of "easy intubation" was 93% in the interventional phase versus 78% in the noninterventional phase (p < 0.001). First-success-rate intubation was higher in the interventional phase (304/308; 98.7%) compared with the noninterventional phase (754/801, 94.1%; p = 0.005). Intubation in the interventional phase showed decreases in the incidence of difficult laryngoscopy (12/308 [3.9%] v 157/801 [19.6%]; p < 0.001), as well as moderate or difficult intubation (5/308 [1.6%] v 57/801 [7.1%]; p < 0.001).

CONCLUSIONS

The use of the McGrath videolaryngoscope as the first intubation option for tracheal intubation in cardiac surgery improves the percentage of patients with "easy" intubation," increasing glottic view and first-success-rate intubation and decreasing the incidence of moderate or difficult intubation.

Complications and degree of difficulty of orotracheal intubation in the Intensive Care Unit before and after the establishment of an intubation protocol for critically ill patients: a prospective, observational study

OBJECTIVE

The objective of our study was to compare the degree of difficulty and complications related to tracheal intubation in an Intensive Care Unit (ICU) before and after the introduction of an intubation protocol based on the Difficult Airway Society guidelines for the management of tracheal intubation in critically ill adults, published in 2018.

METHODS

Prospective, observational study comparing all intubations performed in our ICU over 2 periods: pre-protocol (January 2015-January 2019) and post-protocol (February 2019-July 2022). The material used for intubation, the degree of difficulty, and intubation-related complications were recorded.

RESULTS

During the study period, 661 patients were intubated - 437 in the pre-protocol period (96% by direct laryngoscopy) and 224 in the post-protocol period (53% with direct laryngoscopy, 46% with video laryngoscopy). We observed an improvement in laryngeal view in the post-protocol period compared to the pre-protocol period (Cormack-Lehane ≥ 2b in 7.6% vs. 29.8%, p < 0.001), and a decrease in the number of moderate-to-severely difficult intubations (6.7% vs. 17.4%, p < 0.001). The first-pass success rate was 92.8% in the post-protocol period compared to 90.2% pre-protocol (p = 0.508). We did not find significant differences in complications between the periods studied.

CONCLUSIONS

Intubations performed in the post-protocol period were associated with improved laryngeal view and fewer cases of difficult intubation compared with the pre-protocol period.

Creation of an artificial intelligence model for intubation difficulty classification by deep learning (convolutional neural network) using face images: an observational study

Background

Tracheal intubation is the gold standard for securing the airway, and it is not uncommon to encounter intubation difficulties in intensive care units and emergency rooms. Currently, there is a need for an objective measure to assess intubation difficulties in emergency situations by physicians, residents, and paramedics who are unfamiliar with tracheal intubation. Artificial intelligence (AI) is currently used in medical imaging owing to advanced performance. We aimed to create an AI model to classify intubation difficulties from the patient’s facial image using a convolutional neural network (CNN), which links the facial image with the actual difficulty of intubation.

Methods

Patients scheduled for surgery at Yamagata University Hospital between April and August 2020 were enrolled. Patients who underwent surgery with altered facial appearance, surgery with altered range of motion in the neck, or intubation performed by a physician with less than 3 years of anesthesia experience were excluded. Sixteen different facial images were obtained from the patients since the day after surgery. All images were judged as “Easy”/“Difficult” by an anesthesiologist, and an AI classification model was created using deep learning by linking the patient’s facial image and the intubation difficulty. Receiver operating characteristic curves of actual intubation difficulty and AI model were developed, and sensitivity, specificity, and area under the curve (AUC) were calculated; median AUC was used as the result. Class activation heat maps were used to visualize how the AI model classifies intubation difficulties.

Results

The best AI model for classifying intubation difficulties from 16 different images was generated in the supine-side-closed mouth-base position. The accuracy was 80.5%; sensitivity, 81.8%; specificity, 83.3%; AUC, 0.864; and 95% confidence interval, [0.731-0.969], indicating that the class activation heat map was concentrated around the neck regardless of the background; the AI model recognized facial contours and identified intubation difficulties.

Conclusion

This is the first study to apply deep learning (CNN) to classify intubation difficulties using an AI model. We could create an AI model with an AUC of 0.864. Our AI model may be useful for tracheal intubation performed by inexperienced medical staff in emergency situations or under general anesthesia.

Evaluation of the laryngoscopy view using the modified Cormack-Lehane scale during tracheal intubation in an intensive care unit. A prospective observational study

BACKGROUND AND OBJECTVIES

Tracheal intubation in the Intensive Care Unit is associated with a high incidence of difficult intubation and complications. This may be due to a poor view of the glottis during direct laryngoscopy. The aim of this study is to determine if there is a relationship between laryngoscopy view using the modified Cormack-Lehane scale with the incidence of difficult intubation and complications.

METHODS

All patients who were subjected to tracheal intubated with direct laryngoscopy in the Intensive Care Unit over a 45 month period were included in the study. In all patients, an evaluation was made of the laryngoscopy view using the modified Cormack-Lehane scale, as well as the technical difficulty (number of intubations at first attempt, operator-reported difficulty, need for a Frova introducer), and the incidence of complications (hypotension, hypoxia, oesophageal intubation).

RESULTS

A total of 360 patients were included. When the grade of the modified Cormack-Lehane scale was increased from 1 to 4, the incidence of first success rate intubation decreased (1: 97%, 2a: 94%, 2b: 80%, 3: 60%, 4: 0%, p<.001), the incidence of moderate and severe difficulty intubation increased (1: 2%, 2a: 4%, 2b: 36%, 3: 77%, 4: 100%, p<.001.), as well as the need for a Frova guide (1: 7%, 2a: 8%, 2b: 45%, 3: 60%, 4: 100%, p<.001). When the grade of the modified Cormack-Lehane scale increased from 1 to 4, the incidence of hypoxia<90% increased (1: 20%, 2a: 20%, 2b: 28%, 3: 47%, 4: 100%, p=.0073), as well as hypoxia<80% (1: 11%, 2a: 10%, 2b: 12%, 3: 27%, 4: 100%, p=.00398). No relationship was observed between the incidence of hypotension and the grade of the modified Cormack-Lehane scale (p=ns).

CONCLUSIONS

During tracheal intubation in the Intensive Care Unit a close relationship was found between a poor laryngoscopy view using the modified Cormack-Lehane scale and a higher difficulty technique of intubation. A relationship was found between the incidence of hypoxia with a higher grade in the modified Cormack-Lehane scale. No relationship was found between hypotension and the modified Cormack-Lehane scale.