We thank the editorial team in providing an excellent overview with regards to testing for COVID-19 in pre-op surgical patients. 1 This is especially in light of the latest NHS plans for COVID-19 free sites.
The majority of tests currently used by the NHS is based on the nucleic acid amplification tests for viral RNA. Currently the sensitivity and specificity of RT-PCR is unknown. 2 We would like to highlight the statement made by the editorial team that a negative test does not mean that an individual does not have the virus. 1 This is illustrated with a recent case of ours.
We recently had a 61 year old gentleman who had undergone an excisional biopsy for an unknown right cystic neck mass under general anaesthesia. The treatment planning was agreed as per MDT discussion . The provisional diagnosis based on his imaging was a branchial cleft cyst but malignancy of unknown primary origin could not be fully ruled out.
Ultrasound FNA proved inconclusive. PET CT was not undertaken as due to the inflammatory nature of the lesion on the MRI, this investigation would again prove to be inconclusive. He had RT-PCR for COVID-19 before his procedure, which he tested negative. The surgery was uneventful and he was discharged home three days later. He then presented to the acute OMFS oncall team 10 days later, complaining of general malaise and fever over two days. He also complained of symptoms of diarrhoea. He had a repeat swab for COVID-19 and other respiratory viruses. The tests were all negative. He was admitted overnight and an urgent CT PA was requested after a plain film xray suggest possible COVID-19 infection. The CT scan reported ground glass appearances bilaterally in his mid and lower zones of his lungs. As there was no clinical deterioration overnight, he was discharged the following day with antibiotics and instructions to self isolate for 7 days. However, he was readmitted the J o u r n a l P r e -p r o o f following day as he was struggling with shortness of breath when moving and eating. He was admitted to ITU with a type 1 respiratory failure. Further COVID-19 swabs remain negative. He had a COVID blood panel taken which showed a tranferrin level of 821, IL6 223.7 and a trop 8 which although not specific for COVID is typical of the secondary haemophagocytic lymphohistocytosis syndrome seen in COVID-19 and acute respiratory syndromes. This consist of an unremitting fever, cytopaenias, hyperferrintinaemis and an elevated cytocyne profile. 3 Sadly as this letter is written, he currently remains ventilated in ITU. We have since found that patients within his bay where he was admitted for his surgery have also been poorly and tested positive for COVID-19. Infection diseases are doing a contact tracing to understand what occurred.
Although the RT-PCR test is available in most hospitals, the test should be interpreted with caution. Patients should be treated accordingly with any signs and symptoms of deterioration. Other diagnoses should also be considered. A CT thorax can be used to improve the accuracy of diagnosis in inconclusive cases . 4 However, local policy should always be consulted and staff protected by donning procedure appropriate PPE.