Case Study on the Benefits of Procalcitonin in COVID-19 Treatment

We will now examine a second case study relating to COVID-19 – this time focusing on respiratory infections.

Background

The patient was a 58-year-old female, with a medical history that included obesity, hypertension, and asthma. She was admitted to the ICU from the ED with severe acute respiratory failure – she produced a positive coronavirus result and had a pneumococcal co-infection.

Initial measurements

On admission to ICU the following measurements were taken:

• Temperature = 39.2°C
• WCC = 25.6, CRP = 465, PCT = 75.3
• Lactate = 3.4

She required vasopressor support to keep her Mean Arterial Pressure at 65, despite adequate fluid resuscitation.

Next steps

Organ support and benzyl-penicillin were used, and general improvement was noted in her condition. The antibiotic course was finished after 5 days as her PCT measurements were <0.25, CRP = 54 and WCC = 10.3. She had single organ lung failure, with hallmarks of COVID-19 Acute Respiratory Distress Syndrome (ARDS), as well as segmental pulmonary embolism.

On day 10, her respiratory compliance decreased, and she stopped absorbing nasogastric (NG) feed. The patient’s temperature was recorded at 38.3°C after some apyrexial days. On this day her WCC = 11.2, CRP = 78, and PCT = 2.56.

The next steps to consider would be antibiotic cover for a secondary infection, further microbiological investigation (e.g. blood culture, bronchoscopy sputum sample and urine sample), as well as further chest/abdominal imaging.

Challenges

Diagnosis of ventilator-acquired pneumonia (VAP) is challenging, and current data points towards an increased rate of VAP in COVID-19 pneumonitis. PCT and, more importantly, serial measurement of PCT might help to distinguish between colonisation and an active infection.

If further imaging or bronchoscopy results suggest a new bacterial infection is present, it would be prudent to start broad-spectrum antibiotics. A daily check of PCT level could help in stopping the antibiotics at the appropriate time, to avoid overuse.

To find out more about VAP in COVID-19 patients and the use of PCT, please find further reading in the ‘see also’ section below.