Show Summary Details
Page of

Airway Emergencies 

Airway Emergencies
Chapter:
Airway Emergencies
Author(s):

Laeben Lester

and Lauren Berkow

DOI:
10.1093/med/9780199377275.003.0002
Page of

PRINTED FROM OXFORD MEDICINE ONLINE (www.oxfordmedicine.com). © Oxford University Press, 2020. All Rights Reserved. Under the terms of the licence agreement, an individual user may print out a PDF of a single chapter of a title in Oxford Medicine Online for personal use (for details see Privacy Policy and Legal Notice).

date: 07 April 2020

Airway Fire

Definition

Ignition of combustible materials in the airway.

Presentation

Any fire requires three components: a fuel source, a source of ignition, and oxygen. In the operating room, alcohol-based skin prep solutions, drapes, and the plastic endotracheal tube are fuel sources, cautery and laser beams are the primary sources of ignition, and oxygen is often enriched.

Immediate Management

  • Immediately disconnect the breathing circuit from the endotracheal tube.

  • Inform the surgeons that a fire has occurred.

  • Remove the endotracheal tube.

  • Stop flow of all airway gases, especially N2O.

  • Remove all other flammable materials from the airway.

  • Pour saline into the airway to extinguish any flaming debris.

  • Reintubate the patient, even if injury is not immediately apparent.

Subsequent Management

  • After an airway fire has occurred, the patient should be reintubated and examined by fiberoptic bronchoscopy to determine the extent of airway injury and remove any residual debris.

  • Admission to an intensive care unit (ICU) is often required.

Prevention

  • Use the lowest FiO2 that the patient will tolerate.

  • Determine whether there is risk of a surgical fire before every procedure and formulate a plan of action that will be taken if a fire occurs.

  • Display a protocol for fire prevention and management in every operating room.

  • Whenever the surgical site is near the airway, a 60-mL syringe filled with saline solution should be immediately available.

  • Ensure that the surgeon does not enter the trachea with electrocautery during a tracheostomy.

  • When using lasers on the airway, use the lowest possible FiO2 (40% or less).

  • Avoid use of nitrous oxide for surgery near the airway.

  • Consider insufflating the endotracheal tube (ETT cuff) with saline rather than air.

  • Consider securing the airway as opposed to using a face mask or nasal cannula to administer O2 during head and neck procedures.

Special Considerations

  • The only indication of an airway fire may be a puff of smoke and a flash of light.

  • Alcohol-based skin cleansing solutions are highly flammable, and vapors can be trapped under the drapes if the site is not completely dry.

  • Alcohol-based solutions should not be allowed to pool, and should be given 3 minutes to dry before applying surgical drapes.

  • Fires caused by alcohol-based prep solutions may be invisible under ordinary room lighting and can spread within seconds.

  • If a face mask or nasal cannula oxygen is being used to deliver O2, it may accumulate under drapes and exacerbate a fire.

Further Reading

An Updated Report by the American Society of Anesthesiologists Task Force on Operating Room Fires. Practice advisory for the prevention and management of operating room fires. Anesthesiology. 2013; 118: 271–290.Find this resource:

ECRI Institute. New clinical guide to surgical fire prevention. Patients can catch fire: here’s how to keep them safer. Health Dev. 2009; 38: 314–332.Find this resource:

Rinder CS. Fire safety in the operating room. Curr Opin Anaesthesiol. 2008; 21(6): 790–795.Find this resource:

Aspiration

Definition

Passage of liquid or particulate material into the airway below the vocal cords.

Risk Factors for Aspiration with General Anesthesia

Patient-Related

  • Emergency surgical procedures

  • Inability to clear pharyngeal secretions/poor or absent gag reflex

    • Altered mental status

      • Head injury

      • Medications

    • Bulbar palsy

    • Multiple sclerosis

    • Parkinson disease

    • Guillain-Barréee syndrome

    • Muscular dystrophies

    • Cerebral palsy

  • Increased volume of food and acid in the stomach

    • Recent ingestion of food or fluids

    • Poor gastric emptying/gastroparesis

      • Obesity

      • Diabetes

      • Autonomic neuropathy

      • Pregnancy

      • Ileus

    • Renal failure

    • Head injuries

    • Pain

    • Stress

    • Trauma

  • Intestinal obstruction

    • Pyloric stenosis

  • Incompetence of the lower esophageal sphincter

    • Esophageal reflux

    • Achalasia cardia

    • Hiatal hernia

  • Increased intra-abdominal pressure

    • Obesity

    • Pregnancy

  • Patients with a history of prior upper abdominal surgery

  • Extremes of age

Surgery- and Anesthesia-Related

  • Poor induction technique

    • Large tidal volume or high airway pressure during mask ventilation

    • Incorrectly performed cricoid pressure

  • Difficult intubation resulting in:

    • Gas insufflation into the stomach during mask ventilation

    • Inability to intubate and protect the airway with a cuffed tube

  • Medications and drugs

    • Opioids

    • Topicalization of the airway leading to suppression of the gag reflex

  • Depth of anesthesia

    • Manipulation of upper airway under light anesthesia, leading to gagging and vomiting

  • Patient positioning

    • Trendelenburg position

    • Lithotomy position

  • Increased intra-abdominal pressure

    • Intra-abdominal air insufflation

    • External pressure on the abdomen

Presentation

  • Material found in the oropharynx

  • Wheezing

  • Elevated airway pressure

  • Infiltrates seen on chest X-ray

  • Clinical findings of acute respiratory distress syndrome as syndrome develops

Pathophysiology

Factors affecting outcome after aspiration include:

  • pH of aspirate

    • In general, the extent of injury increases with the acidity of the aspirated material.

    • Aspiration of bile is associated with extensive tissue injury.

  • Volume of aspirated material

  • Particulate matter

    • Particulate matter increases the mortality and incidence of pneumonitis and bacterial overgrowth.

  • Bacterial load

  • Blood in the airway

    • Blood in the airway generally produces minimal injury, but may predispose the patient to infection.

  • Host responses

Differential Diagnosis

  • Laryngospasm or airway obstruction during intubation

  • Bronchospasm, wheezing, or crackles following intubation

  • Hypoventilation, dyspnea, apnea

  • Reduced pulmonary compliance (acute respiratory distress syndrome [ARDS])

Immediate Management

  • Increase FiO2 to 100%.

  • Position the patient with the head down.

  • Maintain cricoid pressure. (Pressure must be released during active vomiting to avoid esophageal rupture.)

  • Suction the nasopharynx and oropharynx.

  • Intubate the trachea. (Consider rapid-sequence induction if the patient is not cooperative.)

  • Suction the lower airway.

  • Initiate mechanical ventilation as indicated. (Positive end-expiratory pressure [PEEP] of at least 5 cm H2O may be required.)

  • Administer bronchodilators (e.g., nebulized albuterol) as indicated.

  • Perform bronchoscopy and remove particulate matter.

  • Defer planned or noncritical surgery where feasible.

  • Obtain chest X-ray and arterial blood gas as indicated.

Subsequent Management

  • Do not administer routine prophylactic steroids.

  • Do not start empiric antibiotics unless there is a clear risk factor (e.g., aspiration of feculent matter). In most cases, initiate antibiotic therapy when there is a clear diagnosis of pneumonia.

  • Do not administer H2 blockers or proton pump inhibitors. Antacids and prokinetic drugs have not been shown to improve outcome after aspiration.

  • Ensure careful fluid management (because volume shifts may occur that lead to pulmonary edema).

Prevention

  • Follow nil per os (NPO) guidelines, except for urgent or emergency surgery.

  • Ensure early control of the airway in patients with poor gag reflex or altered sensorium.

  • Exercise increased vigilance during intubation and extubation.

  • If indicated, administer H2 blockers or proton pump inhibitors at least 90–120 minutes prior to the surgical procedure.

  • Use nonparticulate antacids (e.g., sodium citrate) that decrease the gastric pH.

  • Administration of prokinetic agents (e.g., metoclopramide) before surgery may decrease the risk of aspiration by decreasing the volume of gastric contents.

  • Use rapid-sequence intubation where appropriate.

  • Consider an awake intubation technique if difficulty is suspected.

Special Considerations

  • The incidence of aspiration in adults is roughly 1 in 3000 anesthetics. In patients undergoing emergency surgery, this risk increases to 1 in 600–800, and for caesarean sections under general anesthesia the incidence is 1 in 400–900.

  • Children are at increased risk for aspiration, with an overall incidence of 1 in 2600 and an incidence of 1 in 400 cases during emergency surgery.

  • The consequences of aspiration can be catastrophic: Patients requiring ventilation for more than 48 hours postaspiration have a 50% mortality rate.

Further Reading

Engelhardt T, Webster NR. Pulmonary aspiration of gastric contents in anaesthesia. Br J Anaesth. 1999; 83(3): 453–460.Find this resource:

Kalinowski C, Kirsch J. Strategies for prophylaxis and treatment for aspiration. Best Practice Res Clinical Anesthesiol. 2004; 18(4): 719–737Find this resource:

Practice guidelines for preoperative fasting and the use of pharmacologic agents to reduce the risk of pulmonary aspiration: application to healthy patients undergoing elective procedures. An updated report by the American Society of Anesthesiologists committee on standards and practice parameters. Anesthesiology. 2011; 114(3): 495–511.Find this resource:

Smith G, Ng A. Gastric reflux and pulmonary aspiration in anaesthesia. Minerva Anestesiol. 2003; 69(5): 402–406.Find this resource:

Bleeding following Tonsillectomy

Definition

Significant bleeding from the surgical field after tonsillectomy surgery.

Presentation

Post-tonsillectomy bleeding is most common in the first 24 hours, but can occur within the first week or longer after surgery. Signs of bleeding can include blood coming from the mouth or nose, spitting bright red blood, vomiting bright red or old blood (“coffee ground emesis”), or a metallic taste in the mouth.

Pathophysiology

Causes of bleeding after tonsillectomy include incomplete surgical hemostasis, treatment with antiplatelet agents or anticoagulants, and various coagulopathic states (e.g., hemophilia, von Willebrand disease).

Differential Diagnosis

  • Hemoptysis

  • Nontonsillar bleeding

Immediate Management

  • Evaluate the patient’s airway rapidly.

  • Administer 100% oxygen.

  • Request an emergency evaluation by the otolaryngology service.

  • Consider reintubation if the patient is bleeding rapidly or is unable to protect his or her airway.

  • If intubation is necessary, consider moving the patient to the operating room if this is a safe option.

  • Ensure that adequate suction is available. Blood in the oropharynx may obscure the view during laryngoscopy.

  • Assume that the patient has a full stomach and is at risk for extensive pulmonary aspiration. Rapid-sequence induction of general anesthesia is recommended.

  • Consider a “double set-up” approach with surgeons prepped and gowned for surgical airway before induction of anesthesia.

  • Restore intravascular volume if the patient has signs of hypovolemia.

  • Consider surgical re-exploration of the tonsillar bed.

Special Considerations

  • The blood supply to the tonsils comes from the external carotid artery and its branches. It is sometimes necessary to embolize or ligate the external carotid artery in patients with severe hemorrhage.

Further Reading

Henderson J. Airway management in the adult. In: Miller RD, ed. Miller’s Anesthesia. 7th ed. Philadelphia: Elsevier Churchill Livingstone; 2010:1573–1610.Find this resource:

Koshkareva YA, Cohen M, Gaughan JP, Callanan V, Szeremeta W. Utility of preoperative hematologic screening for pediatric adenotonsillectomy. Ear Nose Throat J. 2012 Aug; 91(8): 346–356.Find this resource:

Cannot Intubate/Can Ventilate

Definition

Inability to intubate the trachea. Adequate face mask ventilation is still possible.

Immediate Management

  • Call for help.

  • Ensure that the FiO2 is 100%.

  • Consider inserting a supraglottic airway (SGA) (e.g., a laryngeal mask airway) if appropriate.

  • If insertion of an SGA is not feasible, and if another attempt at intubation is not appropriate, awaken the patient. Consider deferring the surgery or proceeding with awake intubation.

  • If ventilation becomes difficult, proceed to Cannot Intubate/Cannot Ventilate.

  • If the patient becomes hypoxic and cannot be ventilated, consider a surgical airway (i.e., cricothyrotomy).

  • If another attempt at intubation is warranted, consider the options listed in Box 2.1.

  • Refer to the ASA Difficult Airway Algorithm in the inside front cover of this book.

Subsequent Management

  • Document the intraoperative events carefully in the medical record, with special attention to those techniques that were successful.

  • Explain the sequence of events to the patient and advise him or her to warn future anesthesia providers.

  • Write the patient a “difficult airway” letter. Advise the patient to enroll in a medical registry such as MedicAlert.

Further Reading

Henderson J. Airway management in the adult. In: Miller RD, ed. Miller’s Anesthesia. 7th ed. Philadelphia: Elsevier Churchill Livingstone; 2010:1573–1610.Find this resource:

Practice guidelines for management of the difficult airway: an updated report by the American Society of Anesthesiologists Task Force on Management of the Difficult Airway. Anesthesiology. 2013; 118: 251–270. www.medicalert.org Accessed July 17, 2013.Find this resource:

Cannot Intubate/Cannot Ventilate

Definition

Inability to intubate the trachea. Inability to ventilate the patient by face mask.

Immediate Management

  • Call for help. A surgical airway may become necessary.

  • Ensure that the FiO2 is 100%.

  • Call for the difficult airway cart.

  • Reposition the patient’s head and jaw.

  • Treat suspected laryngospasm with propofol 0.25–0.8 mg/kg or succinylcholine 0.1–2 mg/kg.

  • Insert an airway (e.g., oropharyngeal, nasopharyngeal, laryngeal mask airway) In many such cases the airway can be rescued with insertion of a supraglottic airway.

  • Consider two-person ventilation. One person holds the mask in position and delivers a jaw thrust using both hands while the other ventilates the patient by hand using the reservoir bag and the emergency O2 flush valve as needed.

  • If oxygenation remains satisfactory, consider the use of a video laryngoscope or fiberoptic intubation.

  • Consider a surgical airway (e.g., cricothyrotomy) or transtracheal jet ventilation if the patient is hypoxic.

  • Refer to the ASA Difficult Airway Algorithm in the inside front cover of this book.

Subsequent Management

  • Document the intraoperative events carefully in the medical record, with special attention to those techniques that were successful.

  • Explain the sequence of events to the patient and advise him or her to alert future anesthesia providers.

  • Write the patient a “difficult airway” letter and advise the patient to enroll in a medical registry such as MedicAlert.

  • If a surgical airway has been attempted, request an emergency ear-nose-throat (ENT) consultation.

Special Considerations

  • Ensure that extra help is available before attempting to manage the airway if difficult ventilation and/or ventilation is predicted. Be certain that the patient is adequately preoxygenated before inducing anesthesia. Optimize patient position (“sniffing position,” use of pillows or towels to “ramp up” obese patients). Have special intubation equipment readily at hand.

Further Reading

Henderson J. Airway management in the adult. In: Miller RD, ed. Miller’s Anesthesia. 7th ed. Philadelphia: Elsevier Churchill Livingstone; 2010:1573–1610.Find this resource:

Hsiao J, Pacheco-Fowler V. Videos in clinical medicine. Cricothyroidotomy. N Engl J Med. 2008; 358(22): e25.Find this resource:

Practice guidelines for management of the difficult airway: an updated report by the American Society of Anesthesiologists Task Force on Management of the Difficult Airway. Anesthesiology. 2013; 118: 251–270.Find this resource:

Scrase I, Woollard M. Needle vs surgical cricothyroidotomy: a short cut to effective ventilation. Anaesthesia. 2006; 61(10): 962–974.Find this resource:

Difficult Mask Ventilation

Definition

Inability to provide adequate ventilation with a face mask due to inadequate mask seal, excessive gas leak, or excessive resistance to gas flow.

Presentation

Absent or inadequate chest movement or breath sounds, signs of airway obstruction, cyanosis, gastric air entry causing dilatation, hypoxemia, absent or inadequate exhaled CO2, or low gas flows (reservoir bag does not fill).

Pathophysiology

There are five independent predictors for difficult face mask ventilation: (1) age >55 years; (2) body mass index (BMI) >26 kg/m2; (3) presence of a beard; (4) edentulous patient; and (5) history of snoring.

Immediate Management

  • Increase FiO2 to 100%.

  • Administer a jaw thrust.

  • Ensure that the face mask is correctly sized.

  • Consider an oral airway or a nasopharyngeal airway.

  • Consider inserting a supraglottic airway.

  • Consider two-person ventilation, with one person using both hands to get a good face mask fit and the second person doing the ventilation.

  • Consider endotracheal intubation.

Further Reading

El-Orbany M, Woehlck HJ. Difficult mask ventilation. Anesth Analg. 2009; 109(6): 1870–1880.Find this resource:

Langeron O, Masso E, Huraux C, Guggiari M, Bianchi A, Coriat P, Riou B. Prediction of difficult mask ventilation. Anesthesiology. 2000; 92: 1229–1236.Find this resource:

Practice guidelines for management of the difficult airway: an updated report by the American Society of Anesthesiologists Task Force on Management of the Difficult Airway. Anesthesiology 2013; 118: 251–270.Find this resource:

Difficult Ventilation through an Endotracheal Tube

Definition

High airway pressure and/or inability to adequately ventilate with a tracheal tube in place.

Presentation May Include

  • Stiff rebreathing bag during manual ventilation

  • Increased airway pressure

  • Hypercarbia/elevated end-tidal CO2 levels

  • Unilateral breath sounds

  • Atelectasis seen on chest X-ray

Differential Diagnosis

  • Endobronchial intubation

  • Bronchospasm

  • Kinked endotracheal tube

  • Blood or secretions occluding endotracheal tube

  • Pneumothorax

  • Anaphylaxis

  • Other causes (e.g., ARDS, pulmonary edema)

  • Light anesthesia

  • Patient/ventilator dyssynchrony

Immediate Management

  • Administer 100% oxygen.

  • Auscultate the lung fields for wheezes, crackles, and unilateral breath sounds (endobronchial intubation).

  • Pass a suction catheter down ETT to rule out kinking or the presence of blood, secretions, or a mucous plug.

  • Ventilate the patient with a self-inflating bag (Ambu Bag, Ambu Corp., Ballerup, Denmark) to rule out a problem with the anesthesia machine and patient breathing circuit.

  • Examine the patient for signs of anaphylaxis (e.g., erythema, urticaria, hypotension, tachycardia).

Diagnostic Studies

  • Auscultation of lung fields

  • Chest X-ray

  • Fiberoptic bronchoscopy

Subsequent Management

Treat the underlying problem. If difficulty persists, consider a pulmonary or critical care medicine consult.

Special Cases

Endobronchial Intubation

Inadvertent endobronchial intubation (usually into right mainstem bronchus) is common. Early detection and correction may decrease the risk of complications.

The average distance from the larynx to the carina is 12–14 cm and changes with age, height, and head position. The ETT moves cephalad when the neck is extended and caudad when the neck is flexed and can move as much as 5 cm with maximal cervical range of motion. Small changes in head position can cause endobronchial migration of the ETT in infants and small children. One-lung ventilation as a result of endobronchial ETT placement can cause atelectasis and hypoxemia.

Prevention

  • Observe the endotracheal tube passing through the glottis and ensure that the upper end of the cuff is no more than 3–4 cm beyond the glottis.

  • As a general rule, do not pass the endotracheal tube >21 cm in women and 23 cm in men (measured at the teeth) in average-sized patients.

  • Ensure that equal, bilateral breath sounds are present.

  • Chest X-ray should show the tip of the tube overlying the third or fourth thoracic vertebral body.

  • Fiberoptic bronchoscopy should show the tip of the endotracheal tube 5–7 cm above the carina.

Bronchospasm

Bronchospasm is characterized by wheezing, increased airway pressures, and prolonged expiration time, and can be exacerbated by several triggers, including direct stimulation of the laryngeal and tracheal areas, histamine release associated with drug administration, and noxious stimuli. Bronchospasm should be recognized and treated promptly to avoid hypoxia, hypotension, and increased morbidity and mortality. Anaphylaxis as a cause of bronchospasm should also be included in the differential and ruled out.

Risk Factors: Bronchospasm

  • Asthma

  • Chronic obstructive pulmonary disease

  • Anaphylaxis

  • Smoking

  • Light anesthesia

  • Upper respiratory infection

Management

  • Consider using a supraglottic airway instead of endotracheal intubation when appropriate.

  • Use sevoflurane or isoflurane in at-risk patients.

  • Increase the depth of anesthesia.

  • Sevoflurane and isoflurane are potent bronchodilators.

  • Ketamine and propofol have bronchodilating properties.

  • Increase exhalation time to prevent auto-PEEP.

  • Administer a β‎-agonist (e.g., albuterol MDI 8–10 puffs).

  • Administer an inhaled anticholinergic (e.g., ipratropium 500 μ‎g by neb or MDI).

  • Consider intravenous epinephrine (initial dose 5 to 10 μ‎g) in refractory or severe cases, especially if associated with anaphylaxis.

  • Consider intravenous magnesium (2 g over 20 minutes) in severe cases.

  • Consider administration of intravenous steroids (e.g., dexamethasone 10 mg). (Steroids take 4–6 hours to reach full effect.)

  • If the patient with severe bronchoconstriction or status asthmaticus deteriorates, consider disconnecting the ventilator to allow adequate expiratory time.

  • Ventilator settings may need to be adjusted with a long expiratory phase (1:3 or 1:4), low tidal volume (4–8 mL/kg), low rate (<14 bpm), no or low PEEP (<5) to prevent breath stacking and auto-PEEP, which will result in permissive hypercapnea.

Further Reading

Henderson J. Airway management in the adult. In: Miller RD, ed. Miller’s Anesthesia. 7th ed. Philadelphia: Elsevier Churchill Livingstone; 2010:1573–1610.Find this resource:

Owen RL, Cheney FW. Endobronchial intubation: a preventable complication. Anesthesiology. 1987; 67(2): 255–257.Find this resource:

Stanley D, Tunnicliffe W. Management of life threatening asthma in adults. Cont Educ Anesth Crit Care Pain. 2008; 8(3): 95–99.Find this resource:

Verghese ST, et al. Auscultation of bilateral breath sounds does not rule out endobronchial intubation in children. Anesth Analg. 2004; 99(1): 56–58.Find this resource:

Hemoptysis

Definition

Massive hemoptysis is defined as >600 mL of blood loss in 24 hours, and exsanguinating hemoptysis is considered to be the loss of at least 1000 mL of blood at a rate of >150 mL/h.

Presentation

  • Intubated patients: frothy or frank blood in the ETT.

  • Chest X-ray may show signs of aspirated blood.

Etiology

Infection

  • Bronchitis

  • Necrotizing pneumonia

  • Lung abscess

  • Tuberculosis

  • Fungal infection

  • Parasitic infection

Neoplastic

  • Primary lung cancer

  • Bronchial adenoma

  • Metastatic lung cancer

Cardiovascular

  • Pulmonary embolism

  • Mitral stenosis

  • Left ventricular failure

  • Atrioventricular fistula

  • Congenital heart disease

  • Pulmonary hypertension

Pulmonary

  • Cystic fibrosis

  • Bronchiectasis

  • Tuberculosis

  • Trauma during intubation, endoscopy, or endobronchial surgery

  • Related to tracheostomy

  • Arteriovenous fistula

  • Tumors

Hematologic

  • Upper airway bleeding

  • Disorders of coagulation

  • Disseminated intravascular coagulopathy

  • Thrombocytopenia

  • Uremia

  • Platelet dysfunction

Traumatic

  • Aortic aneurysm

  • Ruptured bronchus

  • Chest injury

  • Foreign body aspiration

  • Tracheal-innominate artery fistula

Iatrogenic

  • Bronchoscopy

  • Lung biopsy

  • Pulmonary artery catheterization

  • Endobronchial brachytherapy

  • Pulmonary hypertension

Alveolar Hemorrhage Syndromes

  • Antiphospholipid syndrome

  • Behçet syndrome

  • Goodpasture syndrome

  • Henoch-Schönlein purpura

  • Systemic lupus erythematosus

  • Wegener’s granulomatosis

  • Hematemesis and aspiration into the airway

  • Idiopathic pulmonary hemosiderosis

Unknown Cause (Cryptogenic)

Immediate Management

  • Increase FiO2 to 100%.

  • Ensure that adequate supplies of blood products are available. In the setting of exsanguinating hemoptysis, consider activating the massive transfusion protocol.

  • Initiate aggressive resuscitation with intravenous (IV) fluids.

  • Support blood pressure as needed with ephedrine (5 mg IV) or phenylephrine (100 mcg IV) boluses. If refractory, consider phenylephrine or epinephrine infusion.

  • Control the airway—intubate if ETT is not in place.

  • In most cases, a single lumen ETT facilitates evacuation of blood from the airway, bronchial lavage, and fiberoptic bronchoscopy.

  • Convert to a double lumen endotracheal tube (DLT) or use a bronchial blocker (BB) to isolate the lungs if indicated (e.g., massive hemorrhage from below the carina).

  • In an emergency when a DLT or a BB is not available, it is possible to push the ETT into a mainstem bronchus on the nonbleeding side to achieve lung isolation.

  • Rigid bronchoscopy identifies the site of bleeding and may allow immediate treatment by cauterization, ablation, or submucosal injection of vasoconstrictors.

  • Consider extracorporeal membrane oxygenation (ECMO) as a bridge to definitive treatment in appropriate patients with life-threatening hemoptysis.

Diagnostic Studies

  • Coagulation tests (PT/INR/aPTT/platelet count)

  • Rigid/fiberoptic bronchoscopy

  • Chest X-ray

  • Computed tomography (CT) scan of the chest and neck as indicated

  • Bronchial arteriogram

  • Echocardiogram to rule out cardiac origin

  • Right heart catheterization

Subsequent Management

  • Correct any coagulation defects (see Coagulopathy, chapter 5).

  • Recombinant activated factor VII is sometimes used with diffuse alveolar bleeding.

  • Treat the primary cause of bleeding.

  • Bronchial artery embolization can be effective in the management of life-threatening massive hemoptysis.

  • A thoracic surgeon should be consulted if bronchial artery embolization is not feasible.

  • Adopt a multidisciplinary approach to management of life-threatening massive intrapulmonary hemorrhage and hemoptysis.

Further Reading

Godfrey S. Pulmonary hemorrhage/hemoptysis in children. Pediatr Pulmonol. 2004; 37: 476–484.Find this resource:

Seijo LM, Daniel H, Sterman DH. Interventional pulmonology. N Engl J Med. 2001; 344(10): 740–749.Find this resource:

Shigemura N, et al. Multidisciplinary management of life-threatening massive hemoptysis: a 10-year experience. Ann Thorac Surg. 2009; 87(3): 849–853.Find this resource:

High-Risk Tracheal Extubation

Definition

Removal of the endotracheal tube from the airway in a patient who is at risk for respiratory complications.

Presentation

The risks of tracheal extubation are underestimated by many anesthesiologists. Although this is a routine procedure in most patients, extubation can cause serious morbidity and mortality. Closed claims data suggest that 12% of claims related to difficult airways occurred at extubation and 5% at recovery. Although the final decision to extubate is made at the end of the surgical procedure or in the ICU or postanesthesia care unit (PACU), planning should begin in the preoperative period and continues through the post-extubation phase.

  • Patients can be classified as “low risk” or “high risk.”

  • Tracheal extubation is an elective procedure.

  • Published guidelines can be used as a framework to guide decision making.

Pathophysiology and Relative Contraindications

  • Removal of the endotracheal tube decreases the anesthesiologists’s ability to control the airway.

  • Surgery and anesthesia can negatively impact airway patency.

  • Residual anesthesia, opioids, and neuromuscular blockade place the patient at risk for hypoventilation.

  • Blunted airway reflexes impair the patient’s ability to manage his or her airway.

  • Reduced functional residual capacity, V/Q mismatch, hypoventilation, diffusion hypoxia, and atelectasis may cause hypercarbia or hypoxemia.

  • Airway injury or edema

  • Cardiovascular instability

  • Neurologic dysfunction

  • Metabolic derangement

  • Electrolyte disturbance

  • Lack of availability of adequate equipment and/or skilled personnel

  • Patient position

  • Reduced access to the airway (e.g., dressings, gastric tubes, cervical collar)

  • Interruption of oxygen supply during transfer

Immediate Management

  • Determine whether the patient is at low or high risk for airway complications after extubation.

  • Confirm safety of tube removal. A key question is: Is it safe to remove this tube?

  • Increase FiO2 to 100%.

  • Suction the airway.

  • Position the patient appropriately.

  • Rule out residual neuromuscular blockade.

  • Establish regular spontaneous breathing and adequate ventilation.

  • Use a bite block. If the patient occludes the tube, consider deflating ETT or SGA cuff to prevent negative pressure edema.

  • The patient should open his or her eyes and follow commands.

  • Minimize head and neck movements.

  • Apply positive pressure, deflate the cuff, and remove the ETT while lung volumes are near vital capacity.

  • Deliver 100% oxygen and confirm airway patency with an anesthetic breathing system.

  • Continue delivering oxygen by face mask until recovery is complete.

  • Consider placement of an airway exchange catheter (AEC) before extubating high-risk patients.

  • Consider placement of SGA as a bridge to extubation.

Diagnostic Studies

  • Examine the airway for edema, bleeding, blood clots, trauma, foreign bodies, or anatomic changes.

  • Consider direct or indirect laryngoscopy.

  • Perform cuff-leak test.

  • Consider chest X-ray.

  • Consider gastric decompression by OG/NG tube if gastric distention is present.

  • Monitor neuromuscular blockade (via twitch monitor or accelerometer).

Airway Exchange Catheters

  • Airway should be suctioned and lidocaine can be administered through ETT.

  • When the patient meets criteria for extubation, lubricated airway exchange catheter (AEC) is placed through the tracheal tube to predetermined depth.

  • Placement of the AEC should be to a maximum depth of 25 cm (to avoid injury to the lung).

  • Remove the tracheal tube over the AEC while maintaining AEC position.

  • Secure AEC to the cheek or forehead with tape.

  • Clearly label the AEC to prevent confusion with the OG/NG tube.

  • Monitor patient in the PACU or ICU while the AEC is in place.

  • Supplemental oxygen can still be given by face mask, nasal cannula, or continuous positive airway pressure (CPAP) as needed.

  • The patient should remain NPO until the AEC is removed.

  • If the AEC triggers coughing, ensure that the tip is above the carina and administer lidocaine via AEC.

  • Remove the AEC when the airway is no longer at risk.

  • If reintubation is necessary, the patient can be intubated over the AEC.

Risk Factors: High-Risk Extubation

  • Known difficult airway

  • Airway deterioration (bleeding, edema, trauma)

  • Restricted airway access

  • Obesity/OSA

  • Aspiration risk

  • Uncertain ability to oxygenate

  • Potentially difficult reintubation

  • General risk (cardiovascular, respiratory, neurological, metabolic, special surgical, or medical)

Prevention

Recognition of extubation as a high-risk phase of anesthesia and appropriate perioperative planning are critical to prevent airway-related morbidity and mortality. Identification of low- and high-risk extubations and continuous reassessment are critical to this process.

Further Reading

Murphy M, Crosby E. The algorithms. In: Hung O, Murphy M, eds. Management of the Difficult and Failed Airway. New York: McGraw-Hill; 2008:15–28.Find this resource:

Peterson GN, et al. Management of the difficult airway: a closed claims analysis. Anesthesiology. 2005; 103: 33–39.Find this resource:

Popat M, et al. Difficult airway society guidelines for the management of tracheal extubation. Anaesthesia. 2012; 67: 318–340.Find this resource:

Intrinsic Upper Airway Obstruction

Definition

Partial or complete airway blockage that increases upper airway resistance (above the larynx) and may cause impaired oxygenation and ventilation.

Presentation

  • Dyspnea

  • Hypercarbia or hypoxemia (may cause obtundation)

  • Snoring

  • Wheezing

  • Stridor

  • Use of accessory muscles of respiration

  • Tracheal tug (downward movement of trachea with inspiration)

  • Retractions at sternal notch

  • Apnea

  • Agitation

  • Thoraco-abdominal dyssynchrony

Pathophysiology

Airway obstruction in the spontaneously breathing patient has many causes, including aspirated foreign bodies, infections (e.g., epiglottitis [Figure 2.1], diphtheria, Ludwig’s angina), laryngospasm, bronchospasm, tumor or a hematoma impinging on the airway, airway trauma, tonsillar hypertrophy, obstructive sleep apnea, nasopharyngeal and oral packing, and airway edema (e.g., anaphylaxis, smoke inhalation, burn injury).

Differential Diagnosis

  • Snoring/obstructive sleep apnea

  • Bronchospasm

  • Bradypnea or apnea from drug overdose or other causes

  • Laryngospasm

Immediate Management

  • Increase FiO2 to 100%.

  • Attempt to open the airway with a jaw thrust, a nasopharyngeal airway, an oropharyngeal airway, or a supraglottic airway device.

  • If possible, administer continuous positive airway pressure (CPAP).

  • Consider nebulized racemic epinephrine and/or intravenous dexamethasone (10 mg IV in an adult).

  • Consider lightening or reversing sedation.

  • Consider nasoendoscopy to assist in diagnosis of etiology.

  • Consider endotracheal intubation for unremitting obstruction.

  • Be prepared for surgical airway as primary or secondary intervention.

  • Consider a helium oxygen mixture as a bridge therapy in stridorous patients if intubation is not feasible.

Further Reading

Mathoera RB, Wever PC, van Dorsten FR, Balter SG, de Jager CP. Epiglottitis in the adult patient. Neth J Med. 2008; 66(9): 373–377.Find this resource:

Nicholau D. The postanesthesia care unit. In: Miller RD, ed. Miller’s Anesthesia. 7th ed. Philadelphia: Elsevier Churchill Livingstone; 2010:2711–2712.Find this resource:

Patil SP, Schneider H, Schwartz AR, Smith PL. Adult obstructive sleep apnea: pathophysiology and diagnosis. Chest. 2007; 132(1): 325–337.Find this resource:

Laryngospasm

Definition

Closure of the upper airway caused by glottic muscle spasm.

Presentation

  • Difficult or impossible face mask ventilation

  • Difficult or impossible ventilation with a supraglottic airway

  • “Crowing” sound on inspiration

Pathophysiology

Laryngospasm is especially common in children and is associated with light planes of anesthesia and irritation of the vocal cords by foreign matter (e.g., blood or secretions).

Differential Diagnosis

  • Bronchospasm

  • Stridor

  • Foreign body in the airway

  • Airway obstruction from edema, infection, tumor, hematoma, etc.

Immediate Management

  • Administer 100% oxygen with positive pressure ventilation.

  • If caused by light anesthesia, administer propofol or other drugs to deepen the level of anesthesia.

  • Consider succinylcholine 0.1 mg/kg IV.

Special Considerations

  • Untreated laryngospasm can rapidly lead to hypoxemia and hypercarbia.

  • Patients who generate high negative inspiratory pressures while attempting to breathe against the obstruction may develop negative-pressure pulmonary edema.

Further Reading

Tsui BC, Wagner A, Cave D, et al. The incidence of laryngospasm with a “no touch” extubation technique after tonsillectomy and adenoidectomy. Anesth Analg. 2004; 98: 327–329.Find this resource:

Visvanathan T, Kluger MT, Webb RK, Westhorpe RN. Crisis management during anaesthesia: laryngospasm. Qual Saf Health Care. 2005; 14(3): e3.Find this resource:

Ludwig’s Angina

Definition

Ludwig’s angina is a multispace infection of the floor of the mouth. The infection usually starts with infected mandibular molars and spreads to the sublingual, submental, buccal, and submandibular spaces.

Presentation

  • Signs of airway obstruction, such as the use of the accessory muscles of respiration

  • Dyspnea

  • Drooling

  • Edema and distortion of airway structures, especially when associated with fever and leukocytosis

Pathophysiology

The tongue becomes elevated and displaced posteriorly, which may lead to obstructive apnea, especially when the patient is in the supine position.

Differential Diagnosis

  • Retropharyngeal abscess

  • Submandibular abscess

  • Epiglottitis

  • Dental abscess

Immediate Management

  • Airway management depends on clinical severity, surgical preferences, and other factors (e.g., CT scan or MRI findings).

  • If the clinical situation permits, transport the patient to the operating room for airway management.

  • A skilled surgeon and emergency cricothyroidotomy equipment must be present before intubation is attempted.

  • Consider performing an awake fiberoptic intubation if at all possible (see page [link]). Elective tracheostomy prior to incision and drainage may be necessary in the setting of significant airway compromise.

Subsequent Management

  • Initiate antibiotic therapy, either empiric or based on culture and sensitivity testing.

  • Transfer the patient to the ICU until edema resolves and extubation can be safely achieved.

Special Considerations

  • Loss of the airway is the leading cause of death in patients with Ludwig’s angina.

  • Extubation may be hazardous. Special precautions, such as the use of a tube exchange catheter, may be appropriate.

  • The abscess may rupture spontaneously or after attempts at laryngoscopy and intubation, flooding the hypopharynx with pus that may then be aspirated.

Further Reading

Boscolo-Rizzo P, Da Mosto MC. Submandibular space infection: a potentially lethal infection. Int J Infect Dis. 2009; 13(3): 327–333.Find this resource:

Marple BF. Ludwig angina: a review of current airway management. Arch Otolaryngol Head Neck Surg. 1999; 125(5): 596–599.Find this resource:

Ovassapian A, Tuncbilek M, Weitzel EK, Joshi CW. Airway management in adult patients with deep neck infections: a case series and review of the literature. Anesth Analg. 2005; 100: 585–589.Find this resource:

Rapid-Sequence Intubation

Definition

A technique of inducing general anesthesia so as to reduce the risk of pulmonary aspiration of gastric contents. An induction agent (e.g., propofol or etomidate) is administered, immediately followed by a short-acting neuromuscular blocking agent (e.g., succinylcholine or rocuronium) to quickly render the patient unconscious and chemically paralyzed to block the active vomiting reflex and facilitate airway management. Pressure is usually applied at the cricoid cartilage (Sellick’s maneuver) to compress the esophagus, reducing the risk of passive regurgitation.

Indications

  • Emergency surgery in a patient who has not been fasting

  • Patients with paralytic ileus or acute abdomen

  • Patients with significant reflux or achalasia cardia

  • Patients with acute trauma requiring immediate surgery

  • Women presenting for surgery in the last trimester of pregnancy

Contraindications

  • Patients with anticipated or known difficult airway

  • Situations in which laryngeal injury may be present

Consider awake intubation in these situations.

The Rapid Sequence Induction (“The 9 Ps”)

Preparation

Prepare all necessary equipment and drugs, and have a backup plan.

  • A working laryngoscope and different types of blades. A video laryngoscope may be desirable if a difficult airway is anticipated.

  • ETTs of the desired size with smaller ETTs available. A stylet should be inserted prior to inducing anesthesia.

  • Device to confirm proper placement of ETT (e.g., capnograph)

  • Working suction

  • Gum elastic introducer (Bougie) or Eschmann stylet

  • Appropriately sized SGA for rescue

  • Equipment for emergency tracheotomy/cricothyrotomy where appropriate

  • Functional IV access

  • Appropriate monitoring equipment

Patient Evaluation

  • Evaluate the airway to rule out possible difficult ventilation or intubation.

  • Review possible contraindications to medications.

Preoxygenation

Administer 100% oxygen for 3–5 minutes with a tight seal around the mask. If the patient is cooperative, five vital-capacity breaths are nearly as effective.

Premedication

This should be used judiciously because it may increase the risk of aspiration or delay awakening in the event that the patient cannot be intubated.

  • Midazolam: 0.02–0.05 mg/kg. Use with caution in patients with head injury or those who may need to be awakened rapidly.

  • Fentanyl: 3 mcg/kg IV 2–3 minutes prior

  • Lidocaine: 1.5 mg/kg IV 2–3 minutes prior

  • Consider aspiration prophylaxis such as sodium citrate.

Paralysis and Induction

Rapidly administer an anesthetic followed by a neuromuscular blocking agent. Do not titrate medication to effect.

  • Choose an induction agent:

    • Etomidate: 0.3 mg/kg IV

    • Ketamine: 1–2 mg/kg IV

    • Propofol: 1–2 mg/kg IV

  • Choose a neuromuscular blocking agent:

    • Succinylcholine: 1–2 mg/kg

    • Rocuronium: 1–1.2 mg/kg

Position and Protect the Patient

  • Position the head and neck into the sniffing position by flexing the neck and extending the atlanto-occipital joint. Reposition the head if an adequate view of the glottic opening is not achieved.

  • If the patient is in a cervical spine collar, an assistant must maintain inline stabilization and the front of the collar must be removed.

  • Apply cricoid pressure (Sellick’s maneuver) before induction. Do not release the cricoid pressure until correct ETT position is confirmed.

  • Wait for 45–60 seconds to allow full effect of the neuromuscular blockade.

  • If the patient will tolerate apnea, do not ventilate him or her at this time to prevent gaseous distention of the stomach.

Pass the Endotracheal Tube

Visualize the tube going through the vocal cords.

Proof of Placement

Establish that the ETT is in the correct position by end-tidal capnography, bilateral breath sounds, chest rise, and fogging within the ETT.

Postintubation Care

  • Ventilate.

  • Secure the ETT.

  • Evacuate the stomach.

  • Administer postintubation sedation if out of the operating room (OR).

  • Maintain appropriate postintubation hemodynamics.

Further Reading

Langeron O, Birenbaum A, Amour J. Airway management in trauma. Minerva Anestesiol. 2009; 75(5): 307–311.Find this resource:

Pytka S, Carroll I, Crosby E. Aspiration: risks and prevention. In: Hung O, Murphy M, eds. Mangement of the Difficult and Failed Airway. New York: McGraw-Hill; 2008:77–94.Find this resource:

Reynolds SF, Heffner J. Airway management of the critically ill patient: rapid-sequence intubation. Chest. 2005; 127(4): 1397–1412.Find this resource: