CASE PRESENTATION
A 14-year-old boy, previously fit and healthy, presented to his local
hospital in March 2020 with rapidly developing respiratory symptoms of
breathlessness, cough, and fever over 24 hours post smoking Midwakh,
mixed with crushed Damas tree leaves (Conocarpus Lancifolius). On
admission, he underwent a series of investigations including COVID 19;
started on empirical broad-spectrum antibiotics and oseltamivir, and
underwent a high-resolution computerized tomogram of the chest (HRCT),
which demonstrated interstitial pneumonia with patchy consolidation and
ground-glass appearance (figure 1). Within a few hours, he required
intubation and mechanical ventilation due to significant hypoxia.
On day four of mechanical ventilation, he was transferred to our center
on Volume control-Assist control settings (FiO2 40 - 70 %, PEEP 8,
Tidal volume 400 ml). Initial arterial blood gas upon admission revealed
relative hypoxemia (PaO2 77.9, PCO2 42.3 mm Hg). The patient met the
criteria for moderately severe ARDS (Bilateral infiltrates on
radiographs, PaO2/FiO2 ratio 192 mm Hg (<200) on PEEP 8 and no
cardiogenic cause). He was managed with ultra-short lung-protective
ventilation (Tv ~5 ml/kg), given poor lung compliance.
Neuromuscular blockage and sedation were administered. Auscultation of
the chest revealed bilateral decreased air entry and crackles.
Continuous infusion of low dose furosemide was commenced for a positive
cumulative fluid balance of 4 liters. During his admission, regular
chest physiotherapy was performed.
Flexible bronchoscopy was performed on day 5, which revealed severe
bilateral inflammation, petechial hemorrhages, and erythematous
bronchial walls beside mild increase of airway secretions, in keeping
with fulminant lung injury. Bronchoalveolar lavage had negative
microbiology culture, viral PCR including the COVID-19 PCR and cell
count differentiation of 71 % neutrophils, 5 % Lymphocytes, 6%
monocytes, 18% macrophages, and no eosinophils. A diagnosis of
interstitial pneumonitis with ARDS due to inhaled toxins was considered,
for which the patient was commenced on a five day course of the
following anti-inflammatory medications; intravenous Methyl Prednisolone
one gram/day (15 mg/kg/day), oral hydroxychloroquine (300 mg per day)
and oral azithromycin (500 mg per day). During the PICU admission
course, he developed hypertension and pre-renal failure for which
anti-hypertensive medications were administered, and diuretics were
discontinued. The patient was rehydrated following this episode,
balancing the perfusion of his kidneys and lungs. Antibiotics were
rationalized because of negative microbiology results. On day 10,
high-pressure ventilation was still required despite the high dosage of
methylprednisolone. A repeat chest HRCT scan (figure 2) was performed,
which revealed left lower lobe consolidation and right lower lobe
collapse and the interstitial lung changes with ground glass
appearances. Subsequently, a prolonged period of prone ventilation was
initiated, after which there was a significant improvement of the
ventilator requirements until extubation on day 14. Spirometry was done
five days post-extubation and revealed a restrictive ventilatory pattern
with forced vital capacity (FVC), Forced expiratory volume in one second
(FEV1), and FEV1/FVC being 2.15 L (46.8 %), 2.02 L (53.3%) and 94.09
% (112.8 %) respectively. A minimal global weakness, features of
critical illness myopathy and peripheral neuropathy were noted. The
patient was discharged on a tapering dose of Prednisone.
Follow up at three months post-discharge showed significant recovery
with resolving respiratory symptoms and improving effort tolerance. A
follow-up HRCT Chest (figure 3) at three months post-discharge was
normal, Spirometry has significantly improved with FVC of 3.8 L (91%
predicted), FEV1 of 3.1 L (89% predicted), slightly reduced Diffusion
capacity (DLCO) of 6.3 L (70% predicted) and normal 6 min walk test was
obtained (with a heart rate of 110 bpm before a walk and 121 bpm after.
Oxygen saturation (SpO2) of 100% before the walk and 98% after).