Overview of the Trachea
The trachea or “windpipe” is the one of the most important structures used in breathing. It is a tube about 1 inch in diameter and 4-6 inches long (in a normal adult), located vertically in front of the esophagus.
It is a membrane supported by 16-20 cartilage rings which prevent the trachea from collapsing. These rings are opened on the back, being connected by bands of muscles, which in turn aids the trachea to contract and expand whenever we breathe in and out. 
Trachea also serves as a line of defense whenever we are exposed to certain environmental irritants. The mucous membrane that is lining it on the inside is very sensitive and stimulates the coughing reflex to cough up any foreign body that has entered.
Figure 1: Trachea
Causes of Tracheal Deviation
- A lot of factors may cause the trachea to shift to either sides. Tracheal deviation is the resultant effect wherein it shifts to the area where there is a relatively high negative pressure.
- As it is normally situated vertically on a straight manner from the neck area down to the chest, a change on its anatomical orientation will be an area of concern especially if it is co-presented with other major symptoms. 
- In this article, the different causes of tracheal deviation will be presented but a special approach will be given to pneumothorax since it is said to be the most life threatening condition associated with it.
Figure 2: Tracheal Deviation
Tracheal Deviation on Infants
This is a condition of no clinical concern. The infants up to age of five years old tend to have tracheal deviation which is not linked to any medical conditions. This is due to their relatively short neck compared to the trachea which will then resolve on its own and will be outgrown afterwards. 
Atelectasis is the medical term used for collapsed lung. The lung collapses due to an obstruction or blockage that impedes its ability to sufficiently inflate.
This is the thickening of the pleura (the lining inside the chest cavity) that could have resulted from chronic inflammation and results to calcification.
This is a procedure that is done to treat lung cancer. It is a surgical removal of the lung, partially or completely.
A condition wherein there is an accumulation of fluid between the chest wall and the lungs (also called pleural space). Though tracheal deviation is a significant finding, its manifestation can only be seen once there is a massive amount of fluid involved.
Either benign or malignant, it still can cause tracheal deviation. A large mass found on the lung, bronchi or pleural cavity can displace the trachea to the side. 
When there is an injury to the lungs, pneumothorax may arise. The lungs may collapse due to the large volume of air entering the pleural space. This air will then compress and restrict the expansion of the lungs during inspiration, leading to other life threatening manifestations. Due to the trachea’s proximity to the heart, the signs and symptoms that might be present also have affectation to the heart and the organs surrounding it.
Figure 3: Pneumothorax
Signs and Symptoms
- Respiratory distress or respiratory arrest (considered a cardinal finding)
- Increase in respiratory rate (tachypnea)
- Asymmetry in lung expansion
- Absence or decrease of breath sounds
- Wheezes or crackles (also called as adventitious breath sounds)
- Difficulty in breathing (dyspnea)
- Increase in cardiac rate (tachycardia)
- Decrease in blood pressure (hypotension)
- Distention of the jugular vein (though this one is not always present especially if severe hypotension is present) 
- Other Findings
- Epigastric Pain (rare) 
- Needle Thoracostomy
A gauge 14-16 cannula that is typically used in intravenous insertion will be introduced on the second intercostal space. It will then be advanced until air can be aspirated to the syringe that will be connected to the cannula. Once in place, a guiding needle will be removed to let the air that is trapped inside to escape. Since this procedure is done blindly, it is very risky and raises some concerns and is even labeled that it results to some complications.
- Chest Drain Placement
This one is the most definitive treatment for pneumothorax and is surgically done. A tube will be placed on the pleura, the same mechanism that the air will be allowed to escape. But this one is said to be safer since this is done visually compared to the needle thoracostomy. 
Figure 4: Needle Thoracostomy
Figure 5: Chest Tube Placement
Detection of Tracheal Deviation and other Signs
Deviation of the trachea can be easily detected by grossly examining it or a mere palpation will do. But if you want to ascertain your assessment, you won’t need any high end diagnostic procedure since a simple x-ray will do. There are also common signs and symptoms that can be generally present accompanying tracheal deviation such as:
- Dyspnea (difficulty breathing)
- Abnormal breath sounds (as assessed by a doctor using a stethoscope or even only with the bare ears if it is audible enough ) 
- Acute Coronary Syndrome (ACS)
- Congestive Heart Failure
- Acute Respiratory Distress Syndrome
- Myocardial Infarction
- Cardiac Tamponade
- Rib Fracture 
Tracheal deviation is a manifestation rather than a condition that is why the treatment will be focused on correcting the underlying problems for it to be addressed. Just like in the management of pneumothorax, where chest tube insertion or needle thoracostomy can be performed to remove the pressure inside the pleural space. Overall, tracheal deviation should always be treated with great concern. A prompt and effective management should be started and always on hand since it imposes a great risk which imposes a life threatening state or even death.