Association Between Difficult Airway Predictors and Failed Prehosptial Endotracheal Intubation

Airway management in patients with suspected or confirmed cervical spine injury: Guidelines from the Difficult Airway Society (DAS), Association of Anaesthetists (AoA), British Society of Orthopaedic Anaesthetists (BSOA), Intensive Care Society (ICS), Neuro Anaesthesia and Critical Care Society (NACCS), Faculty of Prehospital Care and Royal College of Emergency Medicine (RCEM)

BACKGROUND

There are concerns that airway management in patients with suspected or confirmed cervical spine injury may exacerbate an existing neurological deficit, cause a new spinal cord injury or be hazardous due to precautions to avoid neurological injury. However, there are no evidence-based guidelines for practicing clinicians to support safe and effective airway management in this setting.

METHODS

An expert multidisciplinary, multi-society working party conducted a systematic review of contemporary literature (January 2012-June 2022), followed by a three-round Delphi process to produce guidelines to improve airway management for patients with suspected or confirmed cervical spine injury.

RESULTS

We included 67 articles in the systematic review, and successfully agreed 23 recommendations. Evidence supporting recommendations was generally modest, and only one moderate and two strong recommendations were made. Overall, recommendations highlight key principles and techniques for pre-oxygenation and facemask ventilation; supraglottic airway device use; tracheal intubation; adjuncts during tracheal intubation; cricoid force and external laryngeal manipulation; emergency front-of-neck airway access; awake tracheal intubation; and cervical spine immobilisation. We also signpost to recommendations on pre-hospital care, military settings and principles in human factors.

CONCLUSIONS

It is hoped that the pragmatic approach to airway management made within these guidelines will improve the safety and efficacy of airway management in adult patients with suspected or confirmed cervical spine injury.

Predictive Factors for First-Pass Intubation Failure in Trauma Patients

Objective

The primary objective of this study was to elucidate risk factors for multiple intubation attempts (MIA) in trauma patients requiring emergent tracheal intubation (ETI). Risk factors for mortality, intensive care unit (ICU) admission, and prolonged ventilation were assessed as secondary outcomes. The association between multiple intubation attempts and adverse outcomes has been well described in the literature. Though previous studies have identified anatomical risk factors for difficult airways, no study to date has investigated predictors for MIA in a trauma setting.

Methods

The retrospective study involved 174 adult patients who required ETI and who presented to a Level 1 Trauma Center's emergency department between January 2019 and December 2022. Comorbidities, demographic information, triage vitals, intubation characteristics, and patient outcomes were identified to ascertain predictive risk factors for MIA. Variables were assessed for statistical significance on unadjusted analysis. Significant variables were entered into multivariate logistic regression models to test for adjusted associations, with p≤.0.05 as statistically significant, and presented as adjusted odds ratios with 95% confidence intervals.

Results

Twenty-six (14.9%) of the 174 patients required multiple intubation attempts. There were no significant associations between MIA and patient gender, age, BMI, race, injury mechanism, or specific body region injuries. On univariate analysis, the MIA group had a statistically significant elevation in mean systolic blood pressure (151.71 ± 45.96 vs 133.55 ± 32.11, p = 0.019) and heart rate (106.30 ± 34.92 vs 93.35 ± 24.82, p < 0.032) compared to subjects with first-pass success. Elevation in systolic blood pressure (SBP) (151.71 ± 45.96 vs 133.55 ± 32.11, aOR 1.03 (1.01-1.06), p < 0.015) was an independent predictor of multiple intubation attempts.

Conclusion

Elevation in SBP was a significant predictor of multiple intubation attempts. Critical appraisal of patients requiring ETI with elevated SBP may mitigate risk in trauma settings.

Success rates of pre-hospital difficult airway management: a quality control study evaluating an in-hospital training program

BACKGROUND

Competence in emergency airway management is key in order to improve patient safety and outcome. The scope of compulsory training for emergency physicians or paramedics is quite limited, especially in Austria. The purpose of this study was to review the difficult airway management performance of an emergency medical service (EMS) in a region that has implemented a more thorough training program than current regulations require, comprising 3 months of initial training and supervised emergency practice and 3 days/month of on-going in-hospital training as previously reported.

METHODS

This is a subgroup analysis of pre-hospital airway interventions performed by non-anesthesiologist EMS physicians between 2006 and 2016. The dataset is part of a retrospective quality control study performed in the ground EMS system of Wiener Neustadt, Austria. Difficult airway missions recorded in the electronic database were matched with the hospital information system and analyzed.

RESULTS

Nine hundred thirty-three of 23060 ground EMS patients (4%) required an airway intervention. In 48 cases, transient bag-mask-valve ventilation was sufficient, and 5 patients needed repositioning of a pre-existing tracheostomy cannula. Eight hundred thirty-six of 877 patients (95.3%) were successfully intubated within two attempts; in 3 patients, a supraglottic airway device was employed first line. Management of 41 patients with failed tracheal intubation comprised laryngeal tubes (n = 21), intubating laryngeal mask (n = 11), ongoing bag-mask-valve ventilation (n = 8), and crico-thyrotomy (n = 1). There was no cannot intubate/cannot ventilate situation. Blood gas analysis at admission revealed hypoxemia in 2 and/or hypercapnia in 11 cases.

CONCLUSION

During the 11-year study period, difficult airways were encountered in 5% but sufficiently managed in all patients. Thus, the training regime presented might be a feasible and beneficial model for training of non-anesthesiologist emergency physicians as well as paramedics.

Body Mass Index >35 as Independent Predictor of Mortality in Severe Traumatic Brain Injury

OBJECTIVE

Severe traumatic brain injury (TBI) has a major influence on polytrauma outcome. The aim of this study was to evaluate the impact of body mass index (BMI) on mortality and early neurologic outcome in patients suffering from severe TBI with a special focus on obesity classes II and III (BMI ≥35).

METHODS

A retrospective cohort analysis of patients suffering from a leading, at least severe TBI and registered in the TraumaRegister DGU was conducted. Patients alive on admission with full status documentation on Glasgow Coma Scale, height, and weight were classified into 4 BMI subgroups. Early neurologic outcome was classified using the Glasgow Outcome Scale.

RESULTS

A total of 1634 patients met the inclusion criteria. Lowest mortality was documented for BMI group 1 (15.2%, BMI 25.0-29.9918.5). Highest mortality was found in BMI group 5 (25.6%, BMI ≥35). BMI ≥35 was an independent predictor of mortality with an odds ratio of 3.15 (95% confidence interval [1.06-9.36], P = 0.039). Further independent mortality predictors were >65 years of age, a Glasgow Coma Scale of ≤13, an Abbreviated Injury Scale_head ≥5, prehospital cardiopulmonary resuscitation, and a prehospital blood pressure of <90 mm Hg. In terms of good early neurologic outcomes, no differences were recorded between the BMI groups (range 59.0%-62.6%, P = 0.087).

CONCLUSIONS

In this study a BMI ≥35 is an independent predictor of mortality and is associated with an inferior early functional neurologic outcome.

Derivation and Validation of The Prehospital Difficult Airway IdentificationTool (PreDAIT): A Predictive Model for Difficult Intubation

Introduction

Endotracheal intubation (ETI) in the prehospital setting poses unique challenges where multiple ETI attempts are associated with adverse patient outcomes. Early identification of difficult ETI cases will allow providers to tailor airway-management efforts to minimize complications associated with ETI. We sought to derive and validate a prehospital difficult airway identification tool based on predictors of difficult ETI in other settings.

Methods

We prospectively collected patient and airway data on all airway attempts from 16 Advanced Life Support (ALS) ground emergency medical services (EMS) agencies from January 2011 to October 2014. Cases that required more than two ETI attempts and cases where an alternative airway strategy (e.g. supraglottic airway) was employed after one unsuccessful ETI attempt were categorized as “difficult.” We used a random allocation sequence to split the data into derivation and validation subsets. Using backward elimination, factors with a p<0.1 were included in the multivariable regression for the derivation cohort and then tested in the validation cohort. We used this model to determine the area under the curve (AUC), and the sensitivity and specificity for each cut point in both the derivation and validation cohorts.

Results

We collected data on 1,102 cases with 568 in the derivation set (155 difficult cases; 27%) and 534 in the validation set (135 difficult cases; 25%). Of the collected variables, five factors were predictive of difficult ETI in the derivation model (adjusted odds ratio, 95% confidence interval [CI]): Glasgow coma score [GCS] >3 (2.15, 1.19–3.88), limited neck movement (2.24, 1.28–3.93), trismus/jaw clenched (2.24, 1.09–4.6), inability to palpate the landmarks of the neck (5.92, 2.77–12.66), and fluid in the airway such as blood or emesis (2.25, 1.51–3.36). This was the most parsimonious model and exhibited good fit (Hosmer-Lemeshow test p = 0.167) with an AUC of 0.68 (95% CI [0.64–0.73]). When applied to the validation set, the model had an AUC of 0.63 (0.58–0.68) with high specificity for identifying difficult ETI if ≥2 factors were present (87.7% (95% CI [84.1–90.8])).

Conclusion

We have developed a simple tool using five factors that may aid prehospital providers in the identification of difficult ETI.