Background: It has been hypothesized that silent hypoxemia is the cause of the rapid progressive respiratory failure with severe hypoxia that occurs in some patients with COVID-19 without warning. Here, we reported one COVID-19 case with the possibility of silent hypoxemia.
Case presentation: A 60-year-old male presented with complaints of cough that he felt starting two weeks before admission without any breathing difficulty. Complaints were accompanied by fever, runny nose and sore throat. Vital signs examination showed blood pressure 130/75 mmHg, pulse 84 times per minute, normal respiratory rate (RR) of 21 times per minute, body temperature 36.5 C, and 99% oxygen saturation with oxygen via nasal cannula 3 liters per minute were recorded. On physical examination, an increase in vesicular sounds and crackles in both lungs were identified. Chest x-ray showed bilateral pneumonia. Nasopharyngeal and oropharyngeal swab real-time polymerase chain reaction tests for COVID-19 were positive. On the third day of treatment, the patient complained of worsening of shortness of breath, but his RR was still normal with 22 times per minute. On the fifth day of treatment, the patient experienced severe shortness of breath with a RR of 38 times per minute. The patient was then intubated and his blood gas analysis showed respiratory alkalosis (pH 7.54, PaO2 58.9 mmHg, PaCO2 31.1 mmHg, HCO3 26.9 mEq/L, SaO2 94.7%). On the eighth day of treatment, his condition deteriorated starting in the morning, with blood pressure 80/40 mmHg with norepinephrine support, pulse 109 times per minute, and 72% SpO2 with ventilator. In the afternoon, the patient experienced cardiac arrest and underwent basic life support, then resumed strained breathing with return of spontaneous circulation. Blood gas analysis showed severe respiratory acidosis (pH 7.07, PaO2 58.1 mmHg, PaCO2 108.9 mmHg, HCO3 32.1 mEq /L, SaO2 78.7%). Three hours later, he suffered cardiac arrest again, but was unable to be resuscitated. The patient eventually died.
Conclusions: Silent hypoxemia might be considered as an early clinical sign of deterioration of patients with COVID-19, thus, the physician may be able to intervene early and decrease its morbidity and mortality.