Case Presentation
A 37-years-old, healthy, non-smoker male construction worker attended our emergency department with a history of dry cough, fever, and shortness of breath for three days. His respiratory rate was 20/min with O2 Saturation of 94% on a nasal cannula 4 L/m, hypotensive on norepinephrine, looked confused but obeyed commands.
Chest radiography showed Non-homogeneous opacities in the right mid and lower zones. Arterial blood gas on admission revealed hypoxemia (PaO2 71 mmHg) and mild hypercapnia (PaCO2 43 mmHg), high bicarbonate concentration (23.6 mmol/L) and pH was 7.366 with normal lactate. Initially, he was started on broad-spectrum antibiotics. His oxygenation maintained with Nasal canula initially. Subsequent ABGs showed elevation PaCO2 and was supported with Bilevel positive airway pressure ventilation (Bi-PAP) alternated with high flow nasal cannula. The respiratory viral panel came positive for Rhinovirus PCR & Human Metapneumovirus PCR, and septic workup were negative.
He improved clinically and weaned from norepinephrine for over 24 hours. However, he continued to require BiPAP due to type 2 respiratory failure with noted episodes of bradypnea (8-10 BPM) and dropped oxygen saturation during sleep. Drug overdose was ruled out, and thyroid functions were normal. He developed mild occasional difficulty of swallowing on 6th day of hospital admission.
In view of persistent type 2 respiratory failure which is unexplainable by pulmonary pathology and mild occasional difficulty of swallowing and bradypnea Neurological evaluation was done showed absent gag reflex, horizontal nystagmus, and wide base walking. Deep tendon reflexes ware exaggerated with impaired sensation in lower limbs. Thin liquid- post swallowing cough was noted, pain while swallowing, so feeding nasogastric tube was inserted. MRI brain and Cervical Spine (see Fig 1 & Fig 2) was done, which revealed Arnold Chiari malformation with upper cervical syrinx suggestive of a Type-I ACM with associated cervico-medullary junction compression. The patient was transferred to the Neuro-surgery Unit for surgical decompression with cervical fixation.