الفهرس | Only 14 pages are availabe for public view |
Abstract The upper airways begin with the nasal cavity and continue over nasopharynx and oropharynx to the larynx and the extrathoracic part of the trachea. The structure and function of this system have a major influence upon the conduction of the air to the lower airways. Functions of the airway include phonation, olfaction, digestion, humidification, and warming of inspired air. The upper airway reflexes consist of many different types of reflex responses such as sneezing, apnea, swallowing, laryngeal closure, coughing, expiration reflex, and negative pressure reflex. Although the activation of upper airway reflexes does not necessarily occur at one particular site of the respiratory tract, individual reflex response is usually considered to be highly specific for the particular respiratory site which has been affected. Tracheal extubation is as important as tracheal intubation for an uneventful patient recovery. Extubation is defined as purposeful removal of the tracheal tube and transition from an established airway to normal natural airway. Good mentation, competent airway, minimal secretions, good respiratory muscle strength and adequate cardiovascular reserve are essential for successful extubation. Extubation failure is defined as the inability of the patient to maintain a patent airway with effective spontaneous ventilation after purposeful removal of the previously placed endotracheal tube (ETT) within a specified time Although the incidence of extubation failure or reintubation after surgery in operation theatre (OT) is relatively uncommon with an incidence of 0.1%–0.45%, it leads to an overall increased mortality. Concerns have been highlighted by different airway societies in their guidelines. Extubation concerns have been well emphasised in the American Society of Anesthesiologists Closed Claims Analysis and National Audit Project 4 (NAP4). The NAP4 report studied the airway-related issues and observed a mortality rate of 5% in patients with extubation failure after general anaesthesia.They reported an incidence of 13% for severe outcomes after extubation failure Pre-existing airway concerns such as difficult mask ventilation, intubation, obesity and obstructive sleep apnoea (OSA) mandate vigilant extubation. The airway may become compromised due to perioperative manipulations (surgical procedure, oedema, collapse, multiple airway management attempts). The common causes for extubation failure include: bronchospasm, poor respiratory efforts, airway obstruction, residual neuromuscular blockade or residual effects of drugs such as sedatives/opioids (delayed recovery). Extubation is an elective procedure, and hence, strategies need to be planned based on the individual patient condition. It is prudent to assess not only the airway but also other medical or surgical factors that have impact on the plan for extubation. |