RT Book, Section A1 Gehlbach, Brian K. A1 Kress, John P. A2 Hall, Jesse B. A2 Schmidt, Gregory A. A2 Kress, John P. SR Print(0) ID 1107718293 T1 Upper Airway Obstruction T2 Principles of Critical Care, 4e YR 2015 FD 2015 PB McGraw-Hill Education PP New York, NY SN 9780071738811 LK accesssurgery.mhmedical.com/content.aspx?aid=1107718293 RD 2024/11/10 AB Suspected upper airway obstruction (UAO) constitutes a medical emergency. The immediate bedside consultation of a clinician experienced in the management of this condition is indicated.The initial evaluation of UAO is focused on determining the severity and suspected site of the obstruction. Arterial desaturation is a late manifestation; better indicators of severity include stridor, poor air movement, accessory muscle use, abnormal mentation or agitation, tachycardia, hypertension, and pulsus paradoxus.Infections represent important causes of oropharyngeal and hypopharyngeal UAO and include Ludwig angina, peritonsillar abscess, and infections of the retropharyngeal and lateral pharyngeal spaces. Otolaryngology consultation is indicated. Depending on the initial site of infection, spread to other critical sites (eg, the mediastinum) may occur.While intubation is not always required in adults with epiglottitis, management in an ICU is mandatory, and intubation equipment and a tracheostomy tray should be at the bedside.Bacterial infections of the larynx are life-threatening. Causative organisms include Staphylococcus aureus, Streptococcus pneumoniae, Haemophilus influenzae, and Corynebacterium diphtheriae.Laryngospasm and laryngeal edema are important causes of postextubation stridor. Prophylactic corticosteroids may be effective at preventing this phenomenon in high-risk patients. A reasonable approach is to administer methylprednisolone 20 mg IV q4h beginning 12 to 24 hours prior to planned extubation and continued until the tube is removed. Patients with postextubation stridor from laryngeal edema may be treated with a short (eg, 24 hours) course of corticosteroids.Long-term intubation may result in a variety of problems related to the upper airway, including endotracheal tube obstruction from secretions, vocal cord injury, subglottic stenosis, and tracheal stenosis.Risk factors for foreign body aspiration in adults include diminished level of consciousness; impaired swallowing mechanism or diminished upper airway sensation as a result of neuromuscular disorder, prior cerebrovascular accident, or advanced age; and inability to chew food properly because of poor dentition.All suspected traumatic laryngeal injuries should be evaluated promptly to reduce the immediate risk of UAO, as well as to prevent long-term sequelae such as subglottic stenosis.Early laryngoscopic examination of the upper airway is crucial in the evaluation of burn patients with suspected inhalation injury. The risk of UAO increases throughout the first 24 hours.Functional upper airway obstruction may occur in patients who exhibit abnormal glottic closure during inspiration and/or expiration. There is a high risk of coincident asthma, complicating the evaluation of such patients.Angioedema may result from allergy, hereditary or acquired disorders of the complement cascade, direct release of histamine from mast cells from nonallergic mechanisms (eg, opiates), and from angiotensin-converting enzyme inhibitors.Angioedema from angiotensin-converting enzyme inhibitors may occur at any time during the course of therapy.Helium-oxygen mixtures reduce the density-dependent pressure required to drive airflow across obstructing upper airway lesions, and may stabilize patients with UAO pending definitive therapy.Prompt evaluation and management of suspected UAO may prevent subsequent complications including cardiac arrest, anoxic brain injury, and negative pressure pulmonary edema.