Inflammation of the larynx may result from bacterial or viral infection or inhalation of irritant gases. Unaccustomed overuse of the voice leads to edema of the vocal cords. Laryngitis is characterized by hoarseness and loss of voice. Irritant nonproductive cough may be present. Treatment consists of rest to the voice, steam inhalations, avoidance of smoking, and administration of analgesics and antibodies. In many cases the condition is self-limiting with rest and analgesics.
Paralysis of the vocal cords may be organic or functional. The abductors and the adductors and supplied by the recurrent laryngeal nerves which arise from the vagi. In organic paralysis the abductors, the tensors and the adductors are affected in order of sequence. The completely paralyzed vocal cord lies immobile midway between abduction and adduction (cadaveric position). Abductor paralysis is always organic in nature and it may be uni- or bilateral. On the other hand pure adductor paralysis is always bilateral and it is functional in nature. This is frequently seen in hysteria.
Causes of organic laryngeal paralysis
Involvement of the left recurrent laryngeal nerve is common in mediasternal tumors, aortic aneurysm and enlargement of the left atrium occurring in mitrial stenosis. One or other of the recurrent laryngeal nerves may be affected in the neck by enlargement of the cervical lymph nodes, goiter or other surgical causes. Paralysis of the vagus occurs in infective polyneuritis, diphtheria, fractures of the base of the skull or space occupying lesions in the posterior fossa. Vagal nuclei are affected in brainstem lesions. These include basilar artery insufficiency, bulbar poliomyelitis, motor neuron disease, syringobulbia and tumors.
Symptoms include hoarseness of voice, cough, alteration in the quality of the cough and dyspnea. Organic paralysis is accompanied by cough, whereas hysterical paralysis is not. In bilateral abductor paralysis, the cough is devoid of its explosive phase (“bovine cough”). In unilateral vocal cord paralysis, the hoarseness and loss of voice may disappear with time, since the opposite vocal cord crosses the midline and restores the vocal aperture. Laryngeal paralysis is confirmed by laryngoscopy.
It is symptomatic. Bilateral abductor paralysis results in glottis obstruction and it is fatal if the airway is not established by tracheostomy or intubation. Persons with laryngeal paralysis should avoid swimming and diving, since they cannot hold breath and, therefore, they run the risk of drowning.
Acute laryngeal obstruction may present as a fatal emergency unless relieved in time.
• Foreign bodies may get impacted in the larynx, eg, dentures, large chunks of meat of other foreign bodies, etc. Obstruction by bolus of food is more common in subjects intoxicated with alcohol. This is called “Caf coronary”.
• Angioneurotic edema due to food, inhaled material or insect stings.
• Acute laryngitis and epiglottitis. This is especially common in infants. The organisms include H. Influenzae, pneumococcus or group A streptococcus. Irritant fumes like smoke, noxious chemicals or corrosives cause acute laryngeal edema.
• Chronic progressive obstruction occurs in carcinoma.
Stridor, aphonia and dysnea are the hallmarks of laryngeal obstruction. Acute obstruction in children leads to cyanosis and inspiratory indrawing of the trachea. The movement of a foreign body within the larynx may be palpable during respiratory efforts. When obstruction due to large bolus of food occurs at table, the victim becomes anxious, restless and cyanosed. He tries to cry, but the voice is lost. If the obstruction continues he falls unconscious and death may occur within minutes.
Acute laryngeal obstruction should be suspected when an otherwise healthy individual suddenly becomes choked and cyanotic with loss of voice.
First aid consists of the removal of the foreign body manually or with a pair of tongs. The impacted foreign body can be dislodged by a sudden forcible thud on the chest with the head lowered.
This effective method is to be learnt by all first aid teams. The patient is hugged from behind with the rescuer’s hands crossing each other over the patient’s epigastrium and the chest is compressed suddenly. This helps in dislodging the obstruction. If this fails, the airway should be made patent by tracheostomy or by inserting a few large-bore hypodermic needles in to the trachea. The patient is transported to hospital for further management. Further management of chronic obstruction depends upon the cause.