Guest post: COVID-19 primer for CDI

by Alba Kuqi, MD, CCS, CDIP, CCDS, CRCR, CICA, CSCM

Coronaviruses (CoV) are a large family of viruses that cause illness ranging from the common cold to more severe diseases such as Middle East Respiratory Syndrome (MERS-CoV) and Severe Acute Respiratory Syndrome (SARS-Cove). Novel coronavirus disease (COVID-19) is a new strain that was discovered in 2019 and has not been previously identified in humans. COVID-19 is responsible for a global pandemic.

COVID-19 is caused by SARS-CoV-2, and it is genetically like SARS coronavirus, which was responsible for the SARS outbreak in 2002. The coronaviruses that circulate among humans are typically benign, and they cause about a quarter of all common colds. But occasionally, coronaviruses, like COVID-19, circulate in an animal reservoir and mutate just enough to where they’re able to start infecting and causing disease in humans.

In the case of COVID-19, there was a coronavirus circulating among bats, which are a natural animal reservoir, and it mutated just enough to start infecting an intermediate host, the pangolin (an animal that looks like a cross between an anteater and an armadillo). In late 2019, the coronavirus mutated again and started causing disease in humans.

COVID-19 is now spreading primarily person-to-person and can be spread by asymptomatic carriers as well. Viral particles enter the lungs via droplets, and viral S spike binds to ACE-2 on type two pneumocytes. Other routes of infection (contact, enteric) are possible but it’s unclear if these are significant means of spread. The attack rate is 30%-40%, with an incubation time from four to 14 days typically but can be up to 24 days. The outbreak began in China but has since spread around the world. China notified the World Health Organization (WHO) on December 31, 2019; the first case in the United States was seen in Seattle on January 15, 2020. The WHO declared COVID-19 a pandemic disease on March 11, 2020.

As of March 9, 2020, or roughly three months into the outbreak, there were 109,578 confirmed cases of COVID-19 and 3,809 deaths resulting in a fatality rate of 3.5%, but that represents an average across different countries and timeframes. As a point of comparison, the flu typically causes a fatality rate of 0.1%. According to an article published in The Lancet on March 11, “The potential risk factors of older age, high SOFA [Sequential Organ Failure Assessment] score, and d-dimer greater than 1 μg/mL could help clinicians to identify patients with poor prognosis at an early stage." The article goes on to say that "prolonged viral shedding provides the rationale for a strategy of isolation of infected patients and optimal antiviral interventions in the future."

It's worth pointing out that for COVID-19, the mortality rate differs by the group, and the fatality rate is relatively low if you're below 60-years-old. It is higher in people with comorbid conditions such as hypertension, diabetes, cardiovascular disease, chronic respiratory disease, and cancer. Those conditions are typically more common in older adults, so it is not surprising that they go hand in hand. Although the COVID-19 pandemic is still ongoing, the good news is that in China and in South Korea, the number of new cases per day has dropped off largely due to the aggressive public health measures like quarantining, aggressive testing, and ensuring hospitals have the right equipment and staffing.

Symptoms and diagnostics

Common signs of infection include respiratory symptoms, fever, cough, shortness of breath, and breathing difficulties. In more severe cases, the infection can cause pneumonia, severe acute respiratory syndrome, kidney failure, and even death. Between 65%-80% of patients present with cough, and 45% are febrile on admission. Complete blood count (CBC) might show leukopenia and lymphopenia. Chest x-ray findings might show hazy bilateral, peripheral opacities.

Furthermore, computed tomography (CT) findings might demonstrate ground-glass opacities (GGO), crazy paving, consolidation, rarely may be unilateral. Point of care ultrasounds (POCUS) show numerous B-lines, pleural line thickening, consolidations with air bronchograms. We might consider using POCUS to monitor/evaluate the lungs. To confirm the diagnosis, a reverse transcription-polymerase chain reaction (RT-PCR) test can be done and can detect small amounts of viral RNA. Anyhow, this test is not sensitive.

According to another article from The Lancet published on February 13, 2020, “there seem to be three major patterns of the clinical course of infection: mild illness with upper respiratory tract presenting symptoms; non-life-threatening pneumonia; and severe pneumonia with acute respiratory distress syndrome (ARDS) that begins with mild symptoms for 7–8 days and then progresses to rapid deterioration and ARDS requiring advanced life support."

Treatment and prevention

Treatment is focused on supportive care, such as providing fluids, oxygen, and ventilatory support for ill people. There are also early data showing that Remdesivir, an antiviral drug previously used against Ebola, can be helpful. This medicine is currently being tested in large scale clinical trials in the United States and China. Unfortunately, there is no vaccine currently available against COVID-19. Some are being researched, including one that is in clinical trials and will likely be ready by 2021.

We should avoid person-to-person transmission, and in areas with community transmission, anyone with mild symptoms should wear a mask and self-quarantine in their home. If symptoms worsen, they should call their clinic or use telemedicine to talk to their clinician. Self-quarantine requires having a few weeks’ supply of medications, groceries, household items, and an emergency contact person.

Physicians need to triage and treat patients. Many hospital facilities use a coronavirus assessment tool where patients can check by themselves if they carry any signs or symptoms of coronavirus. Telehealth is essential nowadays as well because of social distancing and self-quarantine.

Coding and documentation

Currently, only confirmed cases of COVID-19 are being coded. CDI professionals need to look for these signs and symptoms by reviewing the entire medical record and placing a query whenever they find it necessary and supported by clinical indicators. It is essential asking for the etiology of signs and symptoms when sequencing the principal diagnosis.

The WHO said that “the COVID-19 disease outbreak has been declared a public health emergency of international concern and an emergency ICD-10 code of U07.1 is assigned to the disease diagnosis of COVID-19.” They further stated that “in ICD-11, the code for the illness would be RA01.0."

Based on the current data, over 80% of patients with COVID-19 have a mild infection, and some people don't develop symptoms at all. For others, they can develop symptoms that range from a pretty mild like fever, cough, and shortness of breath to serious problems like pneumonia. According to the ICD-10-CM Interim Coding Guidelines, “if the provider documents ‘suspected,’ ‘possible,’ or ‘probable’ COVID-19, do not assign code B97.29 (Other coronavirus as the cause of diseases classified elsewhere). Assign code(s) explaining the reason for encounter (such as fever, or Z20.828).”

Severe lung damage can cause acute respiratory distress syndrome (ARDS), which occurs when the lung inflammation is so severe that fluids build up around and within the lungs. The exact cause is unknown but usually diagnosed in critically ill patients or those with severe injuries. Common symptoms include difficulty breathing, fatigue, weakness, cough, and fever. Treatment involves oxygen level management, fluid management, and medication.

The severe infection can cause septic shock, which happens when the blood pressure falls dramatically, and the body's organs are starved for oxygen. This is most likely to occur in people over the age of 60, smokers, and those with previous medical conditions. CDI professionals need to review the vital signs as these provide a baseline for medical necessity, clinical support, present on admission status, and evidence of disease processes (e.g., systemic inflammatory response syndrome, sepsis, infections, respiratory failure). For confirmed ARDS due to COVID-19, assign codes:

• J80, Acute respiratory distress syndrome, and
• B97.29, Other coronavirus as the cause of diseases classified elsewhere

CDI professionals should stay up-to-date on the latest COVID-19 updates and keep an eye out of any new coding and documentation guidelines from the WHO, the Centers for Disease Control and Prevention, and CMS.

Editor’s note: Kuqi is the CDI supervisor at Prime Healthcare in Philadelphia. Contact her at albakuqi88@gmail.com. Opinions expressed are those of the author and do not necessarily reflect those of ACDIS, HCPro, or any of its subsidiaries. For more of ACDIS’ coverage of the COVID-19 pandemic, click here.