Case Report
A developmentally normal 13-year-old female presented to the adult
hospital with 5 days of increasing abdominal pain and distention
associated with decreased oral intake and non-bloody, nonbilious emesis.
She had a history of chronic constipation requiring intermittent use of
polyethylene glycol and magnesium citrate. She reported daily small
watery stools with her last normal bowel movement occurring over one
month prior to presentation.
In the emergency department (ED), she was afebrile with a heart rate of
140-150 beats per minute, respiratory rate of 28 breaths per minute, and
peripheral oxygen saturations (SpO2) below 90%. Physical examination
revealed a distressed female with significant abdominal distention,
tenderness to palpation and associated rigidity. Laboratory evaluation
revealed leukocytosis with white blood count 31.6
103/uL (reference range 4.5-13.5
103/uL), bandemia at 60.9% (reference range
5.0-11.0%), and lactate 2.4 (reference range 0.5-2.2 mmol/L). The
contrast-enhanced abdominal Computed tomography (CT) scan revealed an
obstructing stool ball with massive diffuse upstream colonic distention
(Fig 1). This distention compressed adjacent organs and intrahepatic
inferior vena cava. Chest CT showed multifocal compressive atelectasis
with low lung volumes (Fig 1). She was started on 4 liters nasal canula
and given intravenous fluids and piperacillin/tazobactam. The patient
was transferred to our pediatric institution for concerns of toxic
megacolon and the necessity of surgical fecal decompaction.
Upon arrival, the patient was prepped for urgent decompression. She had
desaturations with SpO2 between 70-80% following sedation and prior to
intubation. Upon with direct laryngoscopy fecal material was visualized
on the vocal cords by the anesthesiologist. Although this procedure was
uncomplicated, she was unable to tolerate extubation and was transferred
to the intensive care unit for ongoing care. Overnight into hospital day
(HD) 1, the patient had symptoms consistent with septic shock requiring
epinephrine and broadened antibiotic coverage to Vancomycin, Cefepime,
and Metronidazole.
Due to continued ventilator support, worsening lung compliance, and
increasing FiO2 requirements, a bronchoscopy with bronchoalveolar lavage
(BAL ) was performed. Tracheobronchial tree was evaluated and
feculent material was noted in several subsections of the right middle
and upper lobes. A total of 20 mL of fluid were instilled with return
notable for feculent small airway casts (Fig 1), sent for cultures and
cytology. The patient subsequently underwent a total of 3 bronchoscopy
procedures with therapeutic lavages for airway clearance resulting in
improved respiratory status and radiologic findings.
BAL cultures grew rare Lactobacillus species and antimicrobial
management was adjusted to solely to piperacillin/tazobactam, for total
10-day course. She tolerated extubation to high flow nasal canula on HD
9 and was weaned to room air on HD 13. She underwent a bowel clean out
after surgical decompression. Her home going bowel regiment included
polyethylene glycol powder 17 grams twice daily and bisacodyl 10 mg
daily, with close gastroenterology follow up.
The patient was ultimately diagnosed with functional constipation.
Initial imaging that assessed for any neurologic, spinal etiologies was
negative. She had normal thyroid function and had not been on any
medications known to delay stool passage. Currently, the patient is
undergoing a comprehensive workup for Hirschsprung’s Disease. With the
inpatient anorectal manometry inconclusive, a second attempt to evaluate
her will be repeated as an outpatient.
Discussion:
Chronic constipation is a relatively prevalent condition, affecting
approximately 10-15 % of the pediatric population with a functional
etiology accounting for up to 6%. Constipation detrimentally impacts
quality of life and incurs a substantial healthcare burden to the
individual[4]. Although fecal impaction is
frequently diagnosed, chronic constipation associated with toxic
megacolon is less prevalent among the pediatric population. Megacolon
criteria is obtained when the sigmoid colon measures 6 cm or more in
diameter. With the presence of toxic megacolon, a volvulus should be
ruled out. Although she presented with the triad of symptoms concerning
for volvulus (abdominal pain, distension, and constipation), this was
not seen on diagnostic modalities[5].
The literature rarely reports presentations of severe constipation
leading to respiratory failure in the pediatric population. Severe
constipation can cause considerable abdominal distention that mimics
patients with ascites or pregnancy. In such instances, there is a
reduction in lung height and an increase in anterior-posterior diameter,
resulting in an overall reduction in chest volume. This deficit in lung
mechanics is caused by abdominal and rib cage restrictions resulting in
a restrictive lung pattern and reduced vital capacity. Significant
abdominal distention critically impacts the mobility of the diaphragm,
causing a reduction of excursion during
inspiration[3].
While the mechanics described above most definitely contributed to our
patient’s respiratory failure, this case highlights the possibility of
aspirated fecal material as a cause of ARDS in profoundly constipated
individuals hospitalized for respiratory failure. ARDS is a disabling
and potential lethal syndrome that is relatively common among
mechanically ventilated patients. This well-known syndrome was recently
redefined as occurring within 7 days of known clinical insult with new
or worsening respiratory symptoms. In addition, bilateral opacities on
radiologic imaging, accompanied with respiratory failure unexplained by
fluid status, are required. Its severity is determined by an
increased fraction of inspired oxygen (FiO2) requirements or
minimum positive end-expiratory pressure (PEEP). The differential
diagnosis includes infections, toxic inhalations, allergies, mechanical
obstructive process, and systemic diseases. This syndrome requires
prompt recognition and urgent interventions to improve any associated
morbidity and mortality, with severe cases carrying a mortality rate up
to 46% in pediatric patients[1].
Although multiple risk factors for the development of ARDS are known,
constipation has not historically been considered as a known factor.
To our knowledge, this is the first case to describe aspiration of
feculent material and removal of airway casts via bronchoscopy with
therapeutic lavage. Although occurring in rare instances, constipation
with abdominal distention must be assessed in the differential diagnosis
of a healthy child with ARDS that could lead to more complicated
conditions of varying severity for the patient.
References:
- Thompson BT, Chambers RC, Liu KD. Acute Respiratory Distress Syndrome.
N Engl J Med. 2017 Aug 10;377(6):562-572.
- Badiani S, McArthur D, Bowley D, Balasubramanian B. Chronic
constipation presenting as acute respiratory distress because of
mediastinal shift. Colorectal Dis. 2010 Jul;12(7 Online):e176-7.
- Luder AS, Segal D, Saba N. Hypoxia and chest pain due to acute
constipation: an underdiagnosed condition? Pediatr Pulmonol. 1998
Sep;26(3):222-3.
- Aziz I, Whitehead WE, Palsson OS, Törnblom H, Simrén M. An approach to
the diagnosis and management of Rome IV functional disorders of
chronic constipation. Expert Rev Gastroenterol Hepatol. 2020
Jan;14(1):39-46.
- Nurko S, Zimmerman LA. Evaluation and treatment of constipation in
children and adolescents. Am Fam Physician. 2014 Jul 15;90(2):82-90.