Prophylactic Catheter Placement via Cricothyroid Membrane or Trans-Tracheally as a 'Safe Exit Strategy' for Anticipated Difficult Airway Patients:A Review of Literature and Evidence

The objective of this review article is to increase awareness of the potential benefit from prophylactically placing an intravenous catheter or central venous catheter transtracheally or through cricothyroid membrane. This may serve as a temporary life saving route for oxygenation or jet ventilation in cases of anticipated difficult airway in the adult patients being undertaken under general anaesthesia and who have a high likelihood of ending in Cannot Intubate; Cannot Oxygenate (CICO) situation.Patients with severe difficult airway are at greatest risk of developing hypoxia especially where the patient despite best counseling denies awake airway management. In these patients, there is a high probability of ending in a CICO situation necessitating urgent cricothyroidotomy, trans-tracheal jet ventilation or other forms of surgical airway. Unfortunately, performing these procedures in precarious situation is not easy. Historically, literature is full of reports of successful trans-tracheal jet ventilation via needle or catheter when faced with CICO situation. However, last two decades have seen case reports and case series of prophylactic placement of intravenous catheter or central venous catheter in patients with predicted difficult airway in anticipation of failed intubation and oxygenation. All these reports favour taking this step as a planned 'Safe Exit Strategy' in the management of predicted difficult airway patient as it offers assurance of excellent oxygenation if the need arises. However, shortcomings have been reported with the use of catheters but fortunately taking simple appropriate measures can circumvent most of them. All these have been discussed with evidence to support the recommendations for this practice.