Anesthetic management of the patient with extracorporeal membrane oxygenator support

[Difficult Airway Management (DAM) Algorithms - A narrative synopsis and site assessment]

Centuries ago an "algorithm" was originally inaugurated to depicture a pathway to solve mathematical problems using a decision tree. Nowadays this tool is also well established in clinical medicine. Ever since management errors in difficult airway handling and subsequent litigations remain high referring to ASA closed claims database. However, even since 2010, the ESA postulates every institution dealing with airway management should have a DAM algorithm (ESA Declaration of Helsinki on Patient Safety in Anaesthesiology). In 2018 a systematic review of 38 international DAM algorithms was published; most of them show a four-step flow chart: failed tracheal intubation, insufficient bag-mask ventilation and supraglottic airway, leads to establish an emergency sugical airway. In conclusion authors state that a universal, globally valid, DAM algorithm is lacking. German language guideline development is governed by the AWMF, which labels guidelines with the highest evidence levels and methodological strength "S3". The ASA published a revised DAM practice guideline in 2022, which was developed by 13 international members and was endorsed by international anesthesiological societies. - Though it is based on a systematic literature search and evaluation, final recommendations (without grading) were generated by a survey among experts in the field: Pre-procedural evaluation of the airway is essential; meanwhile more data are available especially regarding ultrasound examination of the upper airway and in 2022 a promising nomogram was developed for the prediction of difficult laryngoscopy. Pre-procedural planning of expected DAM: it should be decided beforehand, if awake intubation is feasible for the patient. Preoxygenation of every elective patient (3 mins with PEEP 5 cmH₂O, aim: 95% pulse oxymetry) and continuous nasal high-flow oxygen delivery during airway management. In case of unexpectedly difficult/emergency airway, ASA recommends: call for help, use cognitive aid (algorithm), consider restoration of spontaneous breathing, adjust bag-mask ventilation, monitor time passing; if "cannot intubate, cannot oxygenate" situation occurs (etCO₂ < 10 mmHg, < 80% pulse oxymetry) establish surgical airway; if failed consider ECMO therapy, if feasible and available. ASA restricts intubation attempts to 3+ based on experience and decision of the clinician, however evidence shows, that attempts should not exceed 2 attempts to avoid serious complications, e.g. hyoxemia and even cardiopulmonary resuscitation (CPR). Additionally, we recommend a cockpit strategy for airway management using crisis resource elements as used in aviation (situation awareness, sterile communication, read-back/hear-back and canned decisions) and a supervisor/team leader as already established in CPR. Last, but not least, continuous airway management training increases algorithm adherence.

Recent trends in airway management

Clinical airway management continues to advance at a fast pace. To help update busy anesthesiologists, this abbreviated review summarizes notable airway management advances over the past few years. We briefly discuss advances in video laryngoscopy, in flexible intubation scopes, in jet ventilation, and in extracorporeal membrane oxygenation (ECMO). We also discuss noninvasive ventilation in the forms of high-flow nasal cannula apneic oxygenation and ventilation and nasal continuous positive airway pressure (CPAP) masks. Emerging concepts related to airway management, including the physiologically difficult airway and lower airway management, new clinical subspecialties and related professional organizations such as Anesthesia for Bronchoscopy, the Society for Head and Neck Anesthesia, and fellowship training programs related to advanced airway management are also reviewed. Finally, we discuss the use of checklists and guidelines to enhance patient safety and the value of large databases in airway management research.