To best answer the question how long patients should be intubated before receiving tracheostomy, we need to answer subsidiary sets of questions: What are the advantages and disadvantages of tracheostomy and prolonged endotracheal intubation? What are the comparative complication rates? What are the major mechanisms causing complications? Can the rates of complication be modified? and What is the current pragmatic experience from use of tracheostomy in the critically ill, and can a maximum time be set for prolonged oral or nasal endotracheal intubation in different diagnostic groups?
Advantages and Disadvantages
The advantages and disadvantages of endolaryngeal tubes and tracheostomy tubes have been compared and were well reviewed. The comparative complications are shown in Table 1. The major differences are in airway damage with an increased incidence of laryngeal injuries seen with endolaryngeal tubes while an increased incidence of late stenosis is seen after tracheostomy. Immediate and severe complications are seen more frequently after tracheostomy (pneumothorax, 0-5%; bleeding from stomal edge, 5%; and mortality attributable to the technique, <2% for tracheostomy, <1/5,000 for intubations).
Damage from endotracheal tubes to mucosa in the airway is immediate and appears to result from mechanical effects of the tube. Damage to the larynx occurs after more prolonged periods and has been best studied in man by Whited. He described .. symmetrical vocal cord paresis or paralysis associated with arytenoid and posterior commissure edema and erythema. Spontaneous recovery usually occurs over days to weeks, although a 6% incidence of posterior commissure stenosis due to fibrosis in the posterior endolarynx has been noted. This series of200 prospectively enrolled subjects was divided into 3 groups: (1) 2-5 days intubated, (2) 6-10 days intubated, and (3) 11-24 days intubated. Posterior commissure stenosis was seen in all 3 groups, but the incidence and severity increased with increasing length of intubation. Conversion to tracheostomy was preventive. He concluded that prolonging intubation beyond 10 days is unacceptable as a routine policy. Others have suggested that these problems become particularly acute and severe in association with insulin-dependent diabetes mellitus and female gender.
Table 1—Complications from Prolonged Endolaryngeal Intubation (ELT) or Early Tracheostomy (T)
|Acute airway damage Laryngeal|
|Ulceration of vocal cords||+ + +, 51%M||–|
|Posterior commissure syndromes||+ , 6%||—|
|Ulceration||+ +||+ + +|
|False passage||± (esophagus)||+|
|Mortality from procedure||± (1/5,000)||+ ,<2%*|
|Chronic airway damage||+||+ +|
|Nosocomial infection||+||+ +|