Abstract
Objectives: To ascertain if topical lignocaine application in oropharynx prior to swab sampling to test for COVID-19 improves a patient’s comfort and to assess its effect on the swab sample taken to conduct the RT-PCR.
Methods: Adult patients testing positive on the RT-PCR COVID-19 test were sampled again within 48 h after administering topical oropharyngeal anaesthesia. Patients were asked to rate their discomfort on a visual analog scale (VAS) for both sample A and B. A qualitative real-time RT-PCR for detection of SARS-CoV-2 RNA, was performed, and the cycle threshold value (Ct), used as a surrogate marker for the viral load, was measured for the sample taken without lignocaine (sample A) and the sample taken post-lignocaine application (sample B). The difference in Ct values of both the groups was checked for any statistical significance using paired t-test. Wilcoxon signed rank test was used on VAS scores to determine any significant decrease in discomfort.
Results: Forty patients were included in the study. Twenty-nine patients (72.5%) reported the procedure to be more comfortable post-lignocaine application. Median (IQR) discomfort on VAS decreased from 7 (1) to 5 (2) after lignocaine use, which was statistically significant (p < 0.05). Mean Ct value for sample A was 17.21 ± 5.25 and for sample B was 18.44 ± 4.8 (p > 0.05), indicating a non-significant effect of lignocaine on SARS-CoV-2 concentration in the sample.
Conclusion: Topical lignocaine, while improving the comfort of the procedure of oropharyngeal sampling for patient did not alter the SARS-CoV-2 viral load that was detected in nasal and oropharyngeal samples taken together.
Keywords: Lignocaine; RT-PCR; SARS coronavirus.
【저자키워드】 RT-PCR, SARS Coronavirus, Lignocaine, 【초록키워드】 COVID-19, SARS-CoV-2, nasal, RT-PCR, Viral load, Patient, Ct value, sampling, SARS-CoV-2 RNA, Oropharyngeal, Swab, SARS Coronavirus, real-time RT-PCR, group, marker, Concentration, Cycle threshold value, COVID-19 test, Lignocaine, Ct values, anaesthesia, Comfort, Adult patients, statistical significance, SARS-CoV-2 viral load, t-test, discomfort, significant decrease, positive, oropharynx, topical, Alter, paired t-test, swab sample, Wilcoxon signed rank test, IMPROVE, was measured, was used, reported, was performed, determine, statistically significant, checked, Adult patient, asked, IQR, the SARS-CoV-2, 【제목키워드】 COVID-19, Oropharyngeal, Lignocaine, anaesthesia, topical,