Indications for tracheotomy in children have changed in the last 30 years. This is directly due to significant changes in the years 1960 to 1970, when tracheal intubation in treatment of respiratory failure reduced the risk of tracheotomy in those patients. At first children were intubated for 48 hours, and then the decision of tracheotomy was taken (4). In the 1970s it was practiced that in cases where intubation lasted longer than 7 days tracheotomy was inevitable (3). Further development of pediatric anesthesiology and intensive care, together with introduction of new materials of which the intubation tubes are made, allowed longer intubation time and furthermore limited the need for tracheotomy. Analyzing the data from the literature from the last 30 years one can evidently observe a decreasing number of tracheotomies. A decrease in the number of tracheotomies due to acute infections of the respiratory system such as laryngotracheobronchitis or epiglottitis is evident. Prolonged intubation replaced tracheotomy in the above-mentioned respiratory conditions. On the other hand, the number of tracheotomies due to congenital anomalies of the larynx or postintubation narrowing of the larynx is increasing. Also noticeable is an increase in the number of tracheotomies for ensuring ventilation and hygiene of the respiratory tract in chronic diseases, severe congenital malformations or in terminally ill patients (1, 3, 4, 5, 6, 7).

Early indications for tracheotomy can be divided into three groups of diseases:

1^st group ? disturbances of respiratory tract patency,

2^nd group ? diseases in which ventilation monitoring and aided ventilation are needed,

3^rd group ? diseases in which permanent hygiene of the respiratory tract is needed.

The widest group of indications for tracheotomy comprises those with disturbances in patency of the respiratory tract such as: congenital defects of the larynx and trachea (congenital stenosis of the larynx and the trachea, laryngeal webs, laryngeal angiomas, laryngomalacia, tracheomalacia, laryngeal cysts); acquired postintubational laryngeal stenosis; paralysis of the vocal cords; inflammatory conditions of the larynx, trachea and bronchi; foreign body of the larynx; external traumas of the larynx and the trachea; massive maxillofacial trauma obscuring intubation; chemical and thermal burns of the respiratory tract; congenital maxillofacial malformations and blockage of patency of the respiratory tract by tumors in the vicinity of the nasopharynx, throat, larynx and trachea which apply direct pressure from the exterior; and tumors of the neck and the mediastinum.
According to the literature from the last 10 years, the most common indications for tracheotomy in children with disturbed patency of the respiratory tract are:

1. Acquired postintubation stenosis of the larynx.

2. Congenital malformations of the larynx and the trachea.

3. Prolonged intubation (2, 3, 6, 7).

The aim of the study was to analyze additional diseases and local condition of the larynx before intubation in children in whom tracheotomy was performed due to postintubational complications.

In the period of 1990-2009, in our pediatric ENT clinic 124 tracheotomies were performed in children with disturbed patency of the respiratory tract. The indication for tracheotomy in 92 patients (75% of cases) was due to postintubation complications.

In the group of 92 patients with postintubation complications, additional systemic diseases and changed local conditions of the larynx were noticed. They might have had an impact on postintubation complications. In this group of 92 children with postintubation complications, in 62 patients (67.39%) the larynx was normal before intubation and in 30 patients (32.61%) additional diseases or laryngeal malformations were observed.
In the group of children with laryngeal malformation, 22 children had laryngomalacia (73.33%), and 8 children (26.67%) had paralysis of the vocal cords with etiologies other than postintubation.

Only 11 children (11.96%) did not have additional diseases, while in the remaining 81 patients (88.04%) severe general diseases were diagnosed. Diseases of the heart and circulatory system requiring cardiosurgical treatment were diagnosed in 17 (18.48%) patients, respiratory tract diseases in 15 (16.3%), congenital multisystem malformation in 23 (25%), and hypoxia of the central nervous system at birth in 9 (9.78%). In the group of 92 children with postintubation complications of the larynx, clinical signs of laryngeal stridor appeared in the period of 1-21 days after extubation in 37 patients (40.22%). On the other hand, in 55 patients (59.78%) extubation for longer than 1 day was not possible due to stridor and respiratory failure of the patients. All children had undergone tracheotomy in order to reverse the patency of the respiratory tract.

In the presented study 124 cases of tracheotomy in children were analyzed. Indications for tracheotomy were the following conditions: paralysis of the vocal cords, laryngeal angiomas, laryngeal cysts, maxillofacial malformations and postintubation stenosis of the larynx. Postintubation stenosis of the larynx was the most common indication for tracheotomy in the above-mentioned group.

In 124 children available for this study up to 92 postintubation complications of the larynx were diagnosed. The authors have analyzed this group of children taking into consideration the local condition of the larynx during intubation and presence of accompanying diseases. A healthy larynx is less prone to postintubation complications than an unhealthy and changed larynx. These changes might be laryngomalacia, laryngitis and other inflammations of the respiratory tract, laryngeal edema, congenital stenosis of the subglottic area, bilateral vocal cord paralysis, burns of the larynx, and defects of laryngeal cartilages. Jorgensen studied 144 children intubated due to inflammatory changes of the respiratory tract mainly of the trachea and lungs (9). The mean intubation period was about 5.5 days. In about 40% of the patients problems with extubation were experienced, which were related to early changes of intubation such as edema and granulation, and in 4% endoscopic examination revealed subglottic stenosis. Furthermore, McEniery noticed that inflammatory changes of the larynx during intubation may have a direct relation with increased risk of postintubation complications (16). Congenital changes of the larynx such as congenital stenosis of the cricoid cartilage are listed as late postintubation complications. It is often difficult to distinguish congenital from acquired postintubation stenosis of the larynx, especially when the child is intubated immediately after birth (10). The anatomy of the larynx might have an impact on the postintubation complications and their treatment, for instance in Down syndrome, as was illustrated by Boseley, Jacobs, and Miller independently (11, 14, 15). Boseley et al. demonstrated that in children with Down syndrome occurrence of stenosis of the posterior glottis is far more common than in the normal population, and subglottic stenosis is a more serious condition. Intubation of children with massive trauma of the head, maxillofacial region and neck is very difficult (8,12). Difficulties intubating patients after trauma (especially of the larynx) additionally increase the risk of postintubation complications (13). In the presented study abnormal anatomy of the larynx was observed in 30 children (32.61%). Laryngomalacia was the most common congenital malformation and was seen in 22 children. Laryngomalacia caused difficulties intubating the patient and furthermore caused iatrogenic trauma. Because disturbances of the respiratory tract patency in laryngomalacia is due to excessive collapse of the laryngeal cartilages, achieving complete patency of the respiratory tract in those patients after extubation was often impossible.

Gaynor and Greenberg were the first to notice that acute and chronic conditions may provoke severe postintubation complications (17). Toxemic condition, anemia, arterial hypotension, hypoxemia, liver failure, kidney failure, heart failure and lower respiratory tract infections all may lead to disturbances in cellular exchanges, hypoxemia and furthermore more serious changes of the intubated larynx. All these are according to our findings. In the studied group of 92 patients, almost 88% of the patients had already diagnosed serious heart, lung, CNS and/or multisystem diseases.

Of special consideration were patients with congenital heart malformations, who according to Khariwala et al. are predisposed to postintubation laryngeal changes due to recurrent intubation, prolonged tracheal ventilation and risk of injury to the recurrent laryngeal nerve during cardiological operations (18). In our study of 92 children, 18.48% had undergone cardiosurgical operations. In more than 30% of cases paralysis of the recurrent laryngeal nerve due to surgical procedures was observed. This group was characterized by the most serious postintubation changes of the larynx.

At present the most common causes of tracheotomy in children are postintubation complications of the larynx. Children with changes in the vicinity of the larynx, in particular laryngomalacia, are more prone to postintubation complications. Serious systemic diseases related to hypoxia increase the risk of postintubation laryngeal complications. In particular, patients who have undergone cardiosurgical procedures are more predisposed to such complications.