In 1995 J. Benumof, MD, said:" The most compelling educational effort for the anaesthesia community should be to reduce frequency and severity of complications related to managing the airway".
Airway management and the challenge of managing the difficult airway continue to be an interesting clinical field to investigate. Reviewing the publications within this field leads to interesting reflections about how the Difficult Airway Algorithm is actually used in the everyday clinical settings. Are difficult Airway Algorithms too difficult and complex to use when they are needed?
Below you will find selected studies about airway management, highlighting some of the challenges, which anaesthesiologists encounter when handling airways.
Airway algorithms often not used when needed
The fourth National Audit Project of the Royal College of Anaesthetists and Difficult Airway Society (NAP4) was designed to identify and study serious airway complications occurring during anaesthesia. There were 184 cases of airway related events found in the NAP4. Death resulting from an airway problem was found in 38 cases and hypoxia was the most common cause. Eight cases of persistent and non-fatal brain damage were identified. Combined with the rate of death, airway problems actually represented 25% of all events. There were ten events in children under the age of ten and the outcomes included three deaths1. Problems arose when difficult intubation was managed by multiple repeated attempts at intubation. The airway problem regularly deteriorated to a 'can't intubate, can't ventilate' situation (CICV). Poor planning often contributed to poor airway outcomes and when potential difficulty with airway management was identified, the airway algorithm wasn't used as required. Of all 184 cases the most frequent cause and contributory factors were the patient (77% of cases), followed by poor judgement (59%) and lack of education/training (49%)1.
Complications associated with multiple attempts at laryngoscopy
Mort TM investigated complications of airway management in 2.833 emergency tracheal intubations. He found multiple attempts at laryngoscopy to be highly associated with rates of complications. Comparing intubation at 1st or 2nd attempt with those requiring more than 2 attempts of laryngoscopies lead to increased risk of hypoxia from 11.8 to 70%2. Closed Claims Reports have similar indicators of increased problems with repeated attempts at tracheal intubation3.
Difficulties in retaining the algorithm
One study included 36 residents who had an average of 60 (38-108) months of anaesthesia training. Ninety-seven percent had difficulties remembering the ASA Difficult Airway Algorithm and 17% of those had previously been involved in emergency situations with severe complications (death or brain damage) due to insufficient airway management.Thirty-three percent had participated in an airway management course and 71% felt competent regarding airway management.
Eleven of the 12 residents with prior participation in an airway management course felt competent in managing the difficult airway, but did not perform better in the written test than others4.
Discrepancy between algorithms and practice
In many countries airway guidelines have been developed and taught to improve airway management in anaesthesia. Studies have shown that not all clinicians are handling the airway as recommended. NAP4 showed that the utilised clinical procedure during a difficult airway was repeated attempts at laryngoscopy, which is not recommended by the ASA Difficult Airway Algorithm. It is clear that the most difficult airway cases require most attempts of laryngoscopic intubations. However, it is strongly recommended by the ASA Difficult Airway Algorithm to use another technique if direct laryngoscopy isn't successful5.
Are the guidelines too complex?
However, if there is a lack of training or if the airway algorithm is too complex, this message will never be received or remembered in the situation where it is needed. It seems simple to do a sufficient pre-anaesthetic evaluation of the airway, choose a SupraGlottic Airway (SGA) or use another intubation device in the given situation. Many of the events and deaths reported in the NAP4 were likely to have been avoided, but still occurred1. The question is how we can avoid these tragic events from happening in the future?
When all this is said it is important to remember that despite these findings, the incidence with serious complications associated with anaesthesia is low, though when complications occur, they can be fatal for those implicated. |
Welcome to the second newsletter on our Airway eLearning Portal. We hope you will find the topics interesting. This month we feature a discussion on Difficult Airway Management in combination with the Difficult Airway Algorithm. 
