Most Common Complications of Endotracheal Intubation

The most common complications resulting from intubation are trauma to the lips, teeth, pharynx and larynx caused by forceful handling or unintentional pinching of structures. Rocking back on the teeth with the laryngoscope, instead of lifting the scope upward and out ward is a common cause of dental damage. Hypoxia, hypercarbia, acidosis, arrhythmia (variation in the rhythm of the heartbeat), and death can result from improper placement of the endotracheal tube. Intubation of the trachea in bronchospastic patients (bronchial asthma) can induce or exacerbate bronchospasm. Sedation, analgesia, topical or general inhalation anesthesia, transtracheal, and parenteral bronchodilators, and vagolytic agents may ameliorate the bronchospastic response.

Dental Trauma

It is the most frequent type of damage related to direct laryngoscopy. Patients undergoing upper airway management during anesthesia may sustain a dental injury that requires further treatment or extraction. Patients at likely risk for dental injury include those with preexisting poor dentition and those who possess upper airway anatomy that makes direct laryngoscopy or tracheal intubation technically difficult. Use of a plastic shield placed over the upper teeth (if available) and avoidance of using the laryngoscope blade as a lever on the teeth may minimize the likelihood of dental trauma. Should injury occur, prompt consultation with a dentist is often indicated. A dislodged tooth must be found, but if the search is unsuccessful, appropriate radiographs of the head/neck, chest, and abdomen should be obtained to ensure that the tooth has not passed through the glottic opening into the trachea or more distal airways.

Systemic Hypertension and Tachycardia

They frequently accompany direct laryngoscopy and tracheal intubation. These responses are usually transient and mild. In patients with preexisting systemic hypertension or ischemic heart disease, however, these changes may be exaggerated or may jeopardize the balance between myocardial oxygen requirements and delivery. In these patients, duration of direct laryngoscopy should be as short as possible. Serious or persistent cardiac dysrhythmias during tracheal intubation are unlikely if apneic time is minimized and adequate oxygenation and denitrogenation are performed and sufficient analgesia is administered.

Main Stem Bronchus Intubation

Advancing the endotracheal tube too far between the vocal cords, results in a mainstem bronchus intubation which needs to be corrected. If it is not rapidly corrected it may cause atelectasis (collapse of the alveoli) in one of the patient's lung fields, and may cause trauma due to excessive pressures associated with ventilation. The key to detecting this complication is auscultation of the lungs with a stethoscope immediately after intubation. It is also important to auscultate the lungs with a stethoscope anytime there is a change in the pulse oximetry, change in the ease of ventilation, and any time the patient's head or body is repositioned for surgery. Auscultation will help confirm that the endotracheal tube has not been moved.

The chance of endobronchial intubation can be minimized by calculating the proper endotracheal tube length for the patient and then noting the centimeter marking on the tube at the point of fixation at the patient's lips. In adults, taping the endotracheal tube at the patient's lips corresponding to the 21- to 23-cm markings on the tracheal tube usually places the distal end of the endotracheal tube in the midtrachea. Flexion of the patient's head may advance the tube up to 1 .9 c m and convert a tracheal placement into an endobronchial intubation, especially in children. Conversely, extension of the head can withdraw the tube up to 1.9 cm and result in pharyngeal placement. Lateral rotation of the head moves the distal end of the tracheal tube approximately 0.7 cm.

The most common site of a mainstem bronchus intubation is the right side. Signs and symptoms of a mainstem bronchus intubation may include the following:

  • Drop in pulse oximetry reading
  • Unequal breath sounds
  • Wheezing

Measures to take for a mainstem bronchus intubation

  • Pulling the chin up may pull the endotracheal tube back enough to identify this initially occurs more easily in infants and children since there is a small distance between the trachea and the right and left mainstem bronchus.
  • Neonates and infants are difficult to auscultate since breath sounds may be radiated throughout the chest. Listen for breath sounds on the lateral side (right and left) of the chest in pediatric patients.
  • After deflating the cuff, pull the endotracheal tube back under direct visualization with the laryngoscope until lung sounds are equal and bilateral.

Esophageal Intubation

All anesthesia providers will intubate the esophagus from time to time. It is essential to recognize this complication rapidly. Without rapid intervention, the patient will suffer harm. If the endotracheal tube is not in the trachea, abnormal sounds will be auscultated over the stomach with attempted ventilation. There will be an absence of breath sounds over the patient's lung fields with ventilation. Ventilation may be difficult. If endotracheal tube placement is uncertain, remove it, mask ventilate the patient with 100% oxygen, and start over.

Difficult to Ventilate After Successful Intubation

After intubation the endotracheal tube may become obstructed due to a number of causes:

  • Thick secretions in the upper airway.
  • Foreign body or dried mucous in the endotracheal tube.
  • Compression of the tube by surgical gag
  • Pressure of the tube bevel against the tracheal wall
  • The end of the endotracheal tube is against the patient's bronchus or other tissue.
  • Kinking or compression of the endotracheal tube.
  • Endotracheal tube cuff moves to cover the outlet of the endotracheal tube

If after intubation your patient's airways appear to be obstructed, you must rapidly check for these possibilities and make appropriate correction. In particular, check the patency of the tube by passing suction catheter through it, check the position of the tube with laryngoscope, rotate the tube if the bevel and end of ETT attached with tracheal tissue and deflate the cuff in case it has herniated over the end of the tube.

If after you have checked all these points, the patient's airway remains obstructed, you must remove the tube and begin again. You can prevent certain type of obstruction by taking precaution (checking ETT for patency and herniation) before intubation.

Laryngospasm

A laryngospasm occurs when the vocal cords come together. This prevents or reduces the amount of air the patient can inspire or expire. This complication occurs more commonly in the pediatric population during the induction or emergence from anesthesia. Laryngospasm is unlikely if the depth of anesthesia is sufficient during tracheal extubation (laryngeal reflexes suppressed) or the patient is allowed to awaken before tracheal extubation (laryngeal reflexes intact). A patient who is lightly anesthetized at the time of tracheal extubation (laryngeal reflexes neither adequately suppressed nor recovered) is most at risk.

Treatment includes:

  • Continuous positive pressure with oxygen
  • Suctioning secretions
  • If the laryngospasm does not break with positive pressure ventilation administer succinylcholine 0.15-0.3 mg/kg IV. The patient should be monitored closely for bradycardia, atropine 0.01-0.02 mg/kg if Bradycardia occurs. Succinylcholine and atropine can be administered by intramuscular injection. The dose of succinylcholine for intramuscular injection is 4 mg/kg
  • Reintubation if necessary

Aspiration of Gastric Contents

Pulmonary aspiration is inhalation of gastric contents in to the tracheobroncheal tree. This can be caused by passive regurgitation or active vomiting when the patient is unable to protect the airway. Patients undergoing emergency surgery with a full stomach, the pregnant patient, bowel obstruction, the obese patient, diabetics, and patients with gastric reflux disease are at risk for aspiration. Even a well conducted rapid sequence induction may result in this complication. Aspiration can occur during induction of anesthesia, during a difficult intubation, or emergence.

Signs and Symptoms Include

  • Gastric contents in the endotracheal tube despite correct placement in the trachea.
  • Wheezing, rales, or rhonchi (the most common site that aspiration is noted is on the right side of the lung).
  • Hypoxia (large particles of food can block the lung passages).
  • Signs of aspiration may take a few hours to develop on chest x-ray.

Treatment is Supportive and Includes

  • Suction the endotracheal tube. Do not lavage the endotracheal tube. This is not effective and may worsen the situation.
  • Bronchoscopy may be required to remove large food particles, if available.
  • The patient may require postoperative ventilation.
  • Cough, deep breath, and incentive spirometry for patients who are not intubated.
  • Supplemental oxygen may be required. Observe the patient for signs of respiratory distress.
  • Corticosteroids may be considered.
  • Broad spectrum antibiotics may be considered if solid food particles have been aspirated or bacterial pneumonia occurs.

Pharmacologic Aspiration Prophylaxis

Adult patients at risk for the aspiration of gastric contents should have pharmacologic aspiration prophylaxis prior to the use of cricoid pressure and rapid sequence induction. Damage to lung tissue, caused by aspiration, is related to the volume and acidity of the aspirated gastric contents. A combination of medications may help reduce the volume and acidity of gastric contents, in addition to cricoid pressure/rapid sequence induction. These medications should be administered, if available, as long as there are no contraindications. Histamine 2 blocker, such as rantidine 150 mg orally or cimetidine 200-300mg orally, should be administered 60 minutes prior to anesthesia. H2 blockers help decrease gastric acid secretion and the volume of gastric secretions. Metoclopramide promote gastric emptying and increase lower esophageal tone. Metoclopramide should be administered slowly, in a dose of 10 mg IV, 30-60 minutes prior to anesthesia. Onset is within 1-3 minutes and peak effect is less than 1 hour. Do not administer metoclopramide to patients with a bowel obstruction, gastrointestinal bleeding, or pheochromocytoma. A non-particulate antacid such as sodium citrate should be administered immediately prior to the induction of anesthesia. Never use a particulate antacid. If aspiration occurs, the particulate may result in a more severe form of aspiration pneumonia.

Post Extubation Croup

Post extubation croup is more common in children. The peak incidence occurs in children aged 1-4 years. This problem is more likely to occur in patients with a history of infectious croup or post extubation croup. Post extubation croup is characterized by stridor (high pitched noise associated with breathing), a barking and brassy cough, hoarseness, and suprasternal, intercostal, or subcostal retractions (indicating that the patient is working hard to breathe). These symptoms occur due to edema in the subglottic region.

Clinical course of post extubation croup: symptoms occur within 1 hour of extubation. The maximum intensity of symptoms occurs within 4 hours. Symptoms should completely resolve in 24 hours. Knowledge of the cause and the use of a correct sized endotracheal tube, with a small air leak, will decrease this complication.

Factors Associated With Post Extubation Croup

  • Age 1-4 years
  • Tight fitting endotracheal tube with no air leak
  • Traumatic or repeated intubation
  • Prolonged intubation
  • Tissue irritants from the endotracheal tube (cleaning solutions such as cidex)
  • Use of an endotracheal tube with a cuff
  • Patient coughing while intubated
  • Frequent repositioning of the head while intubated
  • History of post extubation croup or infectious croup

Treatment

  • Humidified oxygen and hydration (taking into account the amount of IV fluids given to the patient during surgery.)
  • Racemic epinephrine should be administered, if available, (0.5 ml of 2.25% and 2.5 cc of normal saline by aerosolized inhaled respiratory treatment.
  • Alternatively nebulized (vaporized) epinephrine 0.5% in a dose of 0.5 ml, diluted in 1.5 ml of normal saline should be administered.
  • Corticosteroids should be administered to decrease tissue swelling (i.e. dexamethasone 4-8 mg IV).
  • Patient should be closely monitored after treatment for several hours. If concerns remain about the patient, they should be closely monitored overnight.

Last modified: Tuesday, 15 November 2016, 2:16 PM