Is the Mallampati Score Useful for Emergency Department Airway Management or Procedural Sedation?

Is it safe to use telephone for anaesthesia consultation in high-risk patients before non-invasive surgery? A pilot study in ophthalmology

BACKGROUND

Although telemedicine with video support for preoperative evaluation has been found effective, there is limited research on anaesthesia consultation by phone without video support, particularly among high-risk patients. To evaluate the effectiveness, safety and potential benefits of performing pre-anaesthesia evaluation by phone before eye surgery in patients having non-invasive surgery, we performed an observational study in a French teaching hospital.

METHOD

All elective patients having elective ophthalmic surgery were included to have a consultation by phone instead of an in-person consultation, regardless of the type of anaesthesia or ASA score. The incidence of day-of-surgery cancellations, patient satisfaction and time/distance saved through phone consultations were assessed.

RESULTS

From February to October 2022, data of 3480 patients were analyzed, including 370 (11%) high-risk patients (ASA 3-4). Anaesthesia-related day-of-surgery cancellation rate was 0.5% (n = 20) due to non-compliance with pre-operative instructions. No cancellation was due to inadequate pre-operative evaluation. No difference in cancellation rate was observed between low-risk patients and high-risk patients. Telephone consultations saved patients a mean of 126 min and 86 km. A younger age, an active status and living far from the hospital were associated with phone consultation preference.

CONCLUSION

Phone anaesthesia consultation seems to be effective and safe before ophthalmic surgery, regardless of patient's perioperative risk. In addition, phone consultation provides significant time and distance savings. Our results must be confirmed through a multicentric randomised study comparing phone and traditional consultation in ophthalmology as well as in other non-invasive surgical procedures in a high-risk patients population.

A Prospective Cohort Study on the Respiratory Effect on Modified Mallampati Scoring

Background

Mallampati scoring is a common exam method for evaluating the oropharynx as a part of the airway assessment and for anticipation of difficult intubation. It partitions the oropharynx into 4 categories with scores of 1, 2, 3, and 4. Even though its reliability is known to be limited by confounding factors such as patient positioning, patient phonation, tongue protrusion, and examiner variability, the effect of respiration, i.e., inspiration and expiration, has not yet been formally studied.

Methods

Mallampati scores were collected from 100 surgical patients during both inspiration and expiration and later compared to the score obtained in the medical record, determined by a board certified anesthesiologist.

Results

Score deviations from the medical record reference were compared for both inspiration and expiration showing that respiration affects Mallampati scores; for some patients, the scores improved (i.e., decreased), while in others they worsened (i.e., increased). The respiratory change effect was quantified and visualized by plotting the area under the curve of the histogram of the deviations. 42% of the patients had a worsening of scores by 1 or 2 points with inspiration while 36% of the patients had a worsening of scores by 1 or 2 points with expiration.

Conclusions

Mallampati scoring is commonly used in evaluating the oropharynx as a part of the airway assessment and as a screening tool for difficult intubations. However, as this study points out, the respiratory cycle substantially affects the Mallampati scoring system, with significant deviations of 1 or 2 points. In a scoring system of 4 score categories, these deviations are remarkable.

Left Head Rotation as an Alternative to Difficult Tracheal Intubation: Randomized Open Label Clinical Trial

BACKGROUND

Tracheal intubation is a life-saving intervention, and optimizing the patient's head and neck position for the best glottic view is a crucial step that accelerates the procedure. The left head rotation maneuver has been recently described as an innovative alternative to the traditional sniffing position used for tracheal intubation with marked improvement in glottic visualization.

OBJECTIVE

This study compared the glottic view and intubating conditions in the sniffing position versus left head rotation during direct laryngoscopy.

METHODS

This randomized, open-label clinical trial enrolled 52 adult patients admitted to Baguio General Hospital and Medical Center from September 2020 to January 2021 for an elective surgical procedure requiring tracheal intubation under general anesthesia. Intubation was done using a 45° left head rotation in the experimental group (n=26), while the control group (n=26) was intubated using the conventional sniffing position. Glottic visualization and intubation difficulty with the two procedures were assessed using the Cormack-Lehane grade and Intubation Difficulty Scale, respectively. Successful intubation is measured by observing a capnographic waveform in the end-tidal CO2 monitor after placement of the endotracheal tube.

RESULTS

There was no statistically significant difference in the Cormack-Lehane grade, with 85% (n=44) of patients classified under grades 1 (n=11 and n=15) and 2 (n=11 and n=7) in the left head rotation and sniffing position groups, respectively. In addition, there were no statistically significant differences in the Intubation Difficulty Scale scores of patients intubated with left head rotation or sniffing position; 30.7% (n=8) of patients in both groups were easily intubated, while 53.8% (n=14) in left head rotation and 57.6% (n=15) in sniffing position groups were intubated with slight difficulty. Similarly, there were no significant differences between the 2 techniques in any of the 7 parameters of the Intubation Difficulty Scale, although numerically fewer patients required the application of additional lifting force (n=7, 26.9% vs n=11, 42.3%) or laryngeal pressure (n=3, 11.5% vs n=7, 26.9%) when intubated with left head rotation. The intubation success rate with left head rotation was 92.3% versus 100% in the sniffing position, but this difference was not statistically significant.

CONCLUSIONS

Left head rotation produces comparable laryngeal exposure and intubation ease to the conventional sniffing position. Therefore, left head rotation may be an alternative for patients who cannot be intubated in the sniffing position, especially in hospitals where advanced techniques such as video laryngoscopes and flexible bronchoscopes are unavailable, as is the case in this study. However, since our sample size was small, studies with a larger study population are warranted to establish the generalizability of our findings. In addition, we observed inadequate familiarity among anesthesiologists with the left head rotation technique, and the intubation success rate may improve as practitioners attain greater technical familiarization.

TRIAL REGISTRATION

International Standard Randomised Controlled Trial Number (ISRCTN)ISRCTN23442026; https://www.isrctn.com/ISRCTN23442026.

Safety and efficacy of pediatric sedation protocol for diagnostic examination in a pediatric emergency room: A retrospective study

Pediatric patients undergoing diagnostic tests in the pediatric emergency room are frequently sedated. Although efforts are made to prevent adverse events, no sedation protocol has specified the optimal regimen, dosage, and interval of medication to prevent adverse events. This study analyzed the safety and efficacy of sequential pediatric sedation protocols for pediatric patients undergoing diagnostic tests in the pediatric emergency room of a single tertiary medical center. The medical records of patients aged < 18 years who visited the pediatric emergency room of Seoul Asan Medical Center between January and December 2019 for diagnostic testing were retrospectively reviewed. Sedation protocols consisted of 50 mg/kg and 25 mg/kg chloral hydrate, 0.1 mg/kg and 0.1 mg/kg midazolam, and 1 mg/kg and 0.5 to 1 mg/kg ketamine, administered sequentially at intervals of 30, 20, 10, 10, and 10 minutes, respectively. Patients were assessed prior to sedation, and adverse events were investigated. Of the 289 included patients, 20 (6.9%) experienced adverse events, none serious, and nine (3.1%) failed to reach the depth of sedation required to complete the test. The regimen (P = .622) and dosage (P = .777) of the sedatives were unrelated to the occurrence of adverse events when sedation was performed according to protocol. The sedation protocol used in these patients, consisting of sequential administration of minimum dosages, achieved a sufficient depth of sedation with relatively few adverse events, indicating that this protocol can be used safely and effectively for painless sedation in pediatric patients undergoing diagnostic testing.

Critical element prediction of tracheal intubation difficulty: Automatic Mallampati classification by jointly using handcrafted and attention-based deep features

Preoperative assessment of the difficulty of tracheal intubation is of great importance in anesthesia practice because failed intubation can lead to severe complications and even death. The Mallampati score is widely used as a critical assessment criterion in combination with other measures to assess the difficulty of tracheal intubation. The performance of existing methods for Mallampati classification with artificial intelligence (AI) is unreliable to the extent that the current clinical judgment of the Mallampati score relies entirely on doctors' experience. In this paper, we propose a new method for automatic Mallampati classification. Our method extracts deep features that are more favorable for the Mallampati classification task by introducing an attention mechanism into the basic deep convolutional neural network (DCNN) and then further improves the classification performance by jointly using attention-based deep features with handcrafted features. We conducted experiments on a dataset consisting of 321 oral images collected online. The proposed method has a classification accuracy of 97.50%, a sensitivity of 96.52%, a specificity of 98.05%, and an F1 score of 96.52% after five-fold cross-validation. The experimental results show that our proposed method is superior to other methods, can assist doctors in determining Mallampati class objectively and accurately, and provide an essential reference element for assessing the difficulty of tracheal intubation.

Utilization of submandibular ultrasound to measure oral cavity changes with interventions in routine airway management

Ultrasound is a quick, noninvasive, inexpensive tool that can provide an accurate airway assessment. Tongue thickness, oral cavity height, and their relationship were measured using submandibular ultrasonography with and without oral airway interventions during intubation in 26 patients. The mean tongue thickness to oral cavity height ratio was 0.83 ± 0.03. The percent change of tongue thickness to oral cavity height decreased significantly by 36.47% with an oral airway and by 43.49% with laryngoscope interventions (P < 0.01). This study demonstrates how ultrasound-measured oral cavity ratios change with the placement of airway equipment, and application of these findings may advance our understanding of advanced airway management among diverse patient populations.

Ultrasound for airway management: An evidence-based review for the emergency clinician

BACKGROUND

Airway management is a common procedure performed in the Emergency Department with significant potential for complications. Many of the traditional physical examination maneuvers have limitations in the assessment and management of difficult airways. Point-of-care ultrasound (POCUS) has been increasingly studied for the evaluation and management of the airway in a variety of settings.

OBJECTIVE

This article summarizes the current literature on POCUS for airway assessment, intubation confirmation, endotracheal tube (ETT) depth assessment, and performing cricothyroidotomy with an emphasis on those components most relevant for the Emergency Medicine clinician.

DISCUSSION

POCUS can be a useful tool for identifying difficult airways by measuring the distance from the skin to the thyrohyoid membrane, hyoid bone, or epiglottis. It can also predict ETT size better than age-based formulae. POCUS is highly accurate for confirming ETT placement in adult and pediatric patients. The typical approach involves transtracheal visualization but can also include lung sliding and diaphragmatic elevation. ETT depth can be assessed by visualizing the ETT cuff in the trachea, as well as using lung sliding and the lung pulse sign. Finally, POCUS can identify the cricothyroid membrane more quickly and accurately than the landmark-based approach.

CONCLUSION

Airway management is a core skill in the Emergency Department. POCUS can be a valuable tool with applications ranging from airway assessment to dynamic cricothyroidotomy. This paper summarizes the key literature on POCUS for airway management.