0071643192.pdf

CAUSES

■ Infection: Epiglottitis, croup, retropharyngeal abscess, peritonsillar

abscess, Ludwig angina

■ Medical conditions: Anaphylaxis, angioedema, laryngospasm, neoplasm

■ Trauma: Blunt or penetrating trauma; tongue in presence of altered men-

tal status

■ Physical and chemical agents: Foreign body, burn, caustic ingestion

SYMPTOMS/EXAM

■ The patient will typically appear anxious or agitated and will often prefer

to sit upright.

■ Dyspnea, stridor

■ Drooling or spitting secretions

■ Other symptoms depend on underlying cause (eg, fever and sore throat

with epiglottitis).

DIAGNOSIS

■ Often based on clinical presentation alone

■ Soft-tissue neck XR: May reveal foreign body or inflammation (steeple

sign,which is supraglottic swelling on the AP view typically found in

croup;thumbprint signin epiglottitis; or an irregular tracheal marginin

bacterial tracheitis)

■ Direct laryngoscopy: Can define degree of obstruction

TREATMENT

■ Treatment depends on the underlying cause of the obstruction.

■ Allow the patient to maintain a position of comfort (typically a sniffing

position) and provide supplemental O 2.

■ Immediate procedures to control the airway are needed if the obstruction

is severe or progressing.

■ If foreign body is present or suspected:

■ Heimlich maneuver (see Chapter 1) if patient is awake

■ Direct laryngoscopy and removal with Magill forceps if patient is

unconscious

HYPOXEMIA

Defined as a ↓in blood O 2 (in general, a PaO 2 of<60 mmHg). Hypoxemia

may (or may not) result in inadequate delivery of O 2 to tissues (tissue

hypoxia). Five distinct causes or a combination thereof may →hypoxemia

(see Table 10.4).

SYMPTOMS/EXAM

Hypoxemia can →tissue hypoxiaand cause impaired judgment, motor dys-

function, fatigue, drowsiness, respiratory distress, and respiratory failure.

DIAGNOSIS

■ Formal diagnosis of hypoxemia requires arterial blood gas analysis.

■ Perform history, examination, and obtain studies (eg, CXR, CT-PE), as

indicated, to search for underlying cause.

■ Calculate the alveolar-arterial (A-a) O 2 gradient (to narrow the etiology):

THORACIC AND RESPIRATORY

DISORDERS

Inspiratorystridor is

associated with obstruction

above the glottis. Expiratory

stridor is more likely to result

from intrathoracic obstruction.