COVID-19 pandemic did not impact all countries in the same way, and in Spain, the percentage of intensive care unit (ICU) and the mortality rate patients has been very high. The present work aims to present the first case of the new Coronavirus-2019 (COVID-19) on March 23, 2020, in Tenerife, Canary Islands, Spain, of a patient on Invasive Mechanical Ventilation (IMV) affected by acute pneumonia which was treated by airway clearance techniques (ACT) thinking that she was not infected with COVID-19, since the first polymerase chain reaction (PCR) test was negative. The subject presented septic shock, hypoxemic encephalopathy, and seizures. Right lung base consolidation and pleural effusion were visible in the echography. The thorax x-ray presented subcutaneous emphysema and pleural effusion in the right base and an alveolar-interstitial opacity pattern in the left. Bilateral crackles and rhonchus were evident in the right lung during the lung auscultation. The airway clearance protocol comprises Cough Assist (CA) and chest compressions. The variables collected were the ventilatory parameters, blood gas analysis, and thorax x-ray description. ACT protocol improves gas exchange and expands consolidated lung areas in this atypical clinical case presented. At that time, this type of treatment was not performed on patients affected by COVID-19, and the next day we found that the patient had improved, coinciding with the second PCR test, which was positive.