Immediately after intubation, the lung fields should be auscultated and an x-ray ordered to determine if the tube is placed properly. Because the right bronchus is straighter than the left, the tube may be improperly inserted into the right mainstream bronchus, permitting aeration of the right lung only. If the end of the endotracheal tube rests on the carina (i.e., the area where the trachea bifurcates into the left bronchus and right bronchus), partial or complete obstruction results. Inadvertent slipping of the tube into the esophagus will result in gastric dilatation [1,4].

Prior to removal of an endotracheal tube, the patient should be ventilated, oxygenated, and suctioned to remove tracheal and pharyngeal secretions. The cuff is deflated, and the patient is again suctioned. The tube is then removed. The patient is then placed on supplemental oxygen and carefully observed over the next several hours. The choice of supplemental oxygen by nasal cannula, high-flow oxygen mask, continuous positive airway pressure (CPAP), or bilevel positive airway pressure (BIPAP) is dependent on patient factors. CPAP or BIPAP should be considered for patients at high risk of re-intubation. An extubation failure is classified as a patient who is extubated but re-intubated within 48 hours. This occurs in 10% and 20% of patients undergoing extubation [24].

Excessive pressure on the trachea from the endotracheal tube cuff can decrease blood supply to the area and cause tissue necrosis. This may lead to tracheal stenosis or a tracheoesophageal fistula.

In volume-cycled or volume-limited ventilation, a set amount of air is delivered for each inspiration. The advantage of this form of ventilation is that the tidal volume remains consistent and the pressure necessary to deliver the volume varies, dependent on the patient's lung compliance. Volume-cycled is the most frequently used type of ventilation for adult patients [9].

IMV delivers a preset tidal volume at a specific rate while also providing a continuous flow of air for spontaneous breaths. IMV was originally introduced for the purpose of gradually weaning individuals from ventilators, but the use of this type of ventilation has expanded, and it has become popular for patients who require mechanical ventilation but are able to initiate some inspiratory effort on their own, such as patients with chronic obstructive pulmonary disease. IMV cannot be used for individuals who are apneic (e.g., those who have suffered damage to the brain stem). An advantage of IMV ventilation is that it allows the patient to use respiratory muscles, which prevents atrophy [2,3,5,6].

Physiologic changes occur with the administration of PEEP. PEEP causes an increase in intrathoracic pressure, which decreases the venous return of blood to the heart. The baroreceptors in the thoracic aorta interpret the decreased venous return as hypovolemia and stimulate an increase in production of antidiuretic hormone (ADH). Increased ADH can lead to the development of hypervolemia, which results in decreased cardiac output. Another potential problem encountered is the development of a pneumothorax [2,6].

Patients will occasionally "fight" or "buck" the ventilator, also referred to as "being out of phase with the ventilator." In these cases, the patient attempts to actively exhale while the ventilator is delivering the inspired volume. This conflict should be corrected because it results in decreased volume delivery and excessively high airway pressures. A bag-valve mask may be used to increase volume delivery gradually and decrease the respiratory rate. Altered inspiratory flow rates may be ordered for the ventilator to correct the situation, or medication may be prescribed to sedate the patient and allow the ventilator to function more efficiently [2,8,13,26].

If the patient is receiving PEEP, it should be no higher than 5 cm; otherwise, it will interfere with the patient's independent inspiratory efforts. Vital capacity should be greater than 15 mL/kg of body weight, as this indicates that the patient is able to move enough air. This measurement can be obtained using a respirometer attached to the end of the patient's endotracheal or tracheotomy tube. Maximum inspiratory effort should also be assessed to determine whether the patient's chest expansion is sufficient to produce negative alveolar pressure and stimulate a deep inspiration. The greater the patient's ability to inhale, the more negative the inspiratory pressure will be. This is assessed by attaching a pressure gauge to the end of the endotracheal or tracheotomy tube and instructing the patient to take in a deep breath. The patient is considered to be ready for weaning with a pressure of -25 to -30 cm. Respiratory rate and minute volume measurements should be taken. The respiratory rate should be at least 12 breaths per minute, but no greater than 20 breaths per minute [6,8,13]. Additional criteria for weaning include a stable chest wall, an acceptable chest x-ray, adequate cardiac output, normal body temperature, adequate nutritional status, and a generally well-rested condition.

The major objective of nursing care for patients with chest tubes is to facilitate drainage of fluid and air, fostering lung re-expansion. It is imperative to identify which system is being used and why. After insertion of the chest tube, a dressing is applied using sterile technique. Gauze or a hydrocolloid dressing is wrapped around the insertion site, and wide tape is applied to provide an occlusive dressing. This prevents air from entering the intrapleural space. Although the chest tube is sutured in place, further care should be taken to secure the tube when applying the tape. If drainage is present on the dressing, the physician should be notified [8].

Patients with chest tubes may restrict their breathing and movement not only to minimize pain, but because they fear they may dislodge the tube. They should be informed that the tube is secured with sutures and tape. Movement such as turning, coughing, and deep breathing should be encouraged, as this will facilitate re-expansion of the lung. The patient should be told that pain medication is available to decrease discomfort during breathing exercises. Opioids, however, should be avoided or administered judiciously because they can depress the respiratory rate [8].

The collection receptacle should also be explained to the patient. If suction is necessary, patients should be aware that bubbling and some noise are expected. Patients and family members should be given the opportunity to verbalize fears and ask questions regarding the procedure and equipment. Be aware that chest tubes may seem more frightening to visitors than other sorts of tubes, and be prepared to reassure patients that it is the visitor's lack of knowledge, not the patient's situation, that has caused the reaction [8].