Recurrent episodes of upper airway blockage associated with Ascaris lumbricoides causing cardiopulmonary arrest in a young patient

Abstract

Ascaris lumbricoides (AL) is one of the most common helminthic infections of humans, affecting mainly children and malnourished individuals residing in developing countries. It is estimated the 25% of the world’s population is infected with this nematode. Infection occurs via ingestion of water and food contaminated by Ascaris eggs, causing asymptomatic infection to disease with abdominal pain, vomiting, constipation and faecal passage of worms. The present report concerns an unusual case in which AL travelled retrograde and lodged in the vocal cords causing upper airway obstruction leading to asystolic cardiac arrest.

BACKGROUND

A very rare and serious complication of Ascaris infestation is upper airway obstruction caused by the adult worm if they enter the trachea. There are only few cases in the literature where children or adults with altered sensorium developed fatal respiratory obstruction due to Ascaris.

Our patient was unique because she had no complaints suggestive of an Ascaris infection and subsequently had two episodes of airway obstruction within a few minutes, even though a thorough oropharygeal exam was normal before extubation. She unfortunately experienced anoxic brain injury even though the asystolic arrest was only for 3 min.

CASE PRESENTATION

A 31-year-old woman, a resident of urban Karachi (the largest city in Pakistan) was admitted to the intensive care unit with a diagnosis of viral haemorrhagic fever. She required mechanical ventilation due to excessive nasopharyngeal bleeding. Her clinical condition improved gradually. She was extubated on day 5 in the intensive care unit (ICU); however, within a couple of minutes she developed respiratory distress followed by hypoxia. She was immediately reintubated. During direct laryngoscopy she was found to have a dark brown tube-like organism obstructing the hypopharynx. Upon removal with forceps, it was identified to be a 12 cm long Ascaris lumbricoides worm. The patient was fully awake and conscious soon after reintubation. After thorough oropharyngeal suctioning the patient was extubated 4 h after the first episode. Within 30 s she again had an episode of choking followed by hypoxia, an urgent direct laryngoscopy was performed that revealed a large thick structure that had completely occluded the vocal cords and was partly inside the trachea. The object was removed with McGill forceps and an endotracheal tube was passed. During the course the patient became asystolic requiring cardiopulmonary resuscitation (CPR) for 3 min after which her rhythm and blood pressure returned to normal. The second object was 25 cm long and 3 cm thick at the widest portion (fig 1). This was identified as a large female Ascaris lumbricoides worm. The patient was treated with pyrantel pamoate and maintained on mechanical ventilation.

Figure 1.

Female Ascaris lumbricoides worm, 25 cm long and 3 cm thick at the widest portion recovered from the patient.

On clinical exam and electroencephalography (EEG) she was found to have experienced anoxic brain injury. She underwent tracheostomy and was weaned from the ventilator.

TREATMENT

Pyrantal pamoate was administered.

OUTCOME AND FOLLOW-UP

The patient is in a vegetative state, which is gradually improving.

DISCUSSION

Only five cases reports are described in the literature where children or adults with altered sensorium developed fatal respiratory obstruction due to Ascaris lumbricoides.

Ascaris lumbricoides eggs, after ingestion, hatch in the stomach and duodenum and form larvae that penetrate the intestinal walls and enter the blood vessels. The larvae travel via the portal circulation to the right heart, and subsequently into the pulmonary circulation where they are filtered out in the capillaries. They stay in this vicinity and mature for a few days. They subsequently break into the airways and traverse the bronchi and trachea, epiglottis and pharynx and then are swallowed and reach the jejunum. They mature into adult worms in the jejunum, where they mate and lay their eggs. They ultimately are passed in stools.¹

It has been reported that, rarely, the adult worms may move in a reverse direction towards the pharynx via the oesophagus, and emerge from the mouth or nose or enter the Eustachian tube or even the nasopharyngeal duct.² This usually occurs during sepsis or debilitating illness, with the use of anaesthetic drugs or ascaricidal drugs. These “ectopic wanderers” as they are known, may very rarely result in a serious complication if they obstruct the upper airway or enter the trachea causing asphyxia.² There are only a handful of cases in the literature where children or adults with altered sensorium developed fatal respiratory obstruction due to Ascaris.^3–5

Upper airway obstruction among patients in the ICU after extubation occasionally occurs and is due to vocal cord dysfunction or laryngeal oedema due to trauma from the endotracheal tube.^6,7 The patient probably had a heavy symptom-free infestation of the upper gastrointestinal tract with AL which travelled retrograde via the oesophagus due to incompetence of the lower oesophageal sphincter from the affect of sepsis, drugs and the presence of the nasogastric tube. The deep suctioning of oropharynx after removal of endotracheal tube made her gag and cough, causing the worm to travel up the oesophagus due to reverse peristalsis. She was unable to expel the worm, which had lodged itself at the vocal cords resulting in asphyxia causing hypoxia and subsequently asystolic cardiac arrest. She unfortunately developed significant anoxic brain injury resulting in a persistent vegetative state.

In endemic areas such as China, Southeast Asia and coastal regions of West and Central Africa, AL should be suspected as a cause when a patient develops sudden upper airway obstruction immediately after extubation. Whenever a foreign body is suspected, immediate laryngoscopy must be performed and all efforts be taken to prevent serious complications.

LEARNING POINTS

• Ascaris lumbricoides is a rare cause of acute fatal upper airway obstruction.

• Upper airway obstruction by Ascaris lumbricoides should be considered in the differential diagnosis when a patient develops sudden upper airway obstruction in a highly endemic area.