Place, duration, and design of the study
This prospective single-center study was performed in our department between May 2021 and December 2021.
Ethics
Informed consent was obtained for all patients. The examinations were only performed after a careful explanation of the characteristics, non-invasiveness, and aim of the study. The study was approved by the Ethics Committee of Centro Hospitalar Universitário do Porto (Number: 2021.93 [075-DEFI/078-CE]) and the design complies with the Declaration of Helsinki ethical standards.
Inclusion criteria
Adulthood, OD concomitant with SARS-CoV-2 documented infection), subjective persistence of OD, and a cognitive status that allowed the patient to sign an informed consent and to self-treat with the medical therapeutic proposed.
Exclusion criteria
Chronic rhinosinusitis, recent head trauma with loss of consciousness, olfactory complaints before documented COVID-19, gestation, prior nasal surgery, known olfactory bulb lesion on imaging, neurologic or psychiatric disease, or inability to tolerate nasal endoscopy.
Evaluation
Our evaluation consisted of several steps: A general assessment of days before the onset of hyposmia, co-morbidities, a subjective assessment using the Portuguese Language Olfactory Disorders Questionnaire [12 (link)], and a VAS toward subjective impairment of hyposmia in quality of life. Our VAS consisted of an 11-point scale ranging between 0 and 10, being “not a problem” on the left end of the scale (number 0) and “worst problem in my life” on the right end of the scale (number 10). An objective assessment of olfactory thresholds using the Sniffin´ Sticks threshold test with n-butanol: 16 levels in 48 pens were also performed [13 (link)]. The nasal status assessment was performed by nasal endoscopy for exclusion of nasal pathology and evaluation of Lund-Kennedy score - when a polyp score ≥ 1 was seen, the patient was excluded from our cohort while follow-up and further management were maintained in parallel. Also, all patients underwent olfactory training and adjuvant therapy using the strategy described in the protocol described by Sousa et al. [14 (link)].
Variables evaluated
Age, gender, relevant comorbidities, date of perceived onset of OD, olfactory thresholds, and VAS (related to OD). Patients were re-evaluated after three months, and data was collected.
Statistical analysis
Collected data were analyzed using SPSS version 26 (Statistical Package for Social Studies) - IBM, USA. For numerical values, the range, mean, and standard deviations were calculated. The differences between the two mean values were used using the Mann-Whitney U test. Differences in mean values before and after the intervention were done by Wilcoxon signed ranks test. The correlation between VAS and olfactory thresholds was done using Pearson’s correlation coefficient. To access the confounding variables, ANCOVA analysis was also performed. All reported p-values are two-tailed, with a p-value ≤ 0.05 indicating statistical significance.
This prospective single-center study was performed in our department between May 2021 and December 2021.
Ethics
Informed consent was obtained for all patients. The examinations were only performed after a careful explanation of the characteristics, non-invasiveness, and aim of the study. The study was approved by the Ethics Committee of Centro Hospitalar Universitário do Porto (Number: 2021.93 [075-DEFI/078-CE]) and the design complies with the Declaration of Helsinki ethical standards.
Inclusion criteria
Adulthood, OD concomitant with SARS-CoV-2 documented infection), subjective persistence of OD, and a cognitive status that allowed the patient to sign an informed consent and to self-treat with the medical therapeutic proposed.
Exclusion criteria
Chronic rhinosinusitis, recent head trauma with loss of consciousness, olfactory complaints before documented COVID-19, gestation, prior nasal surgery, known olfactory bulb lesion on imaging, neurologic or psychiatric disease, or inability to tolerate nasal endoscopy.
Evaluation
Our evaluation consisted of several steps: A general assessment of days before the onset of hyposmia, co-morbidities, a subjective assessment using the Portuguese Language Olfactory Disorders Questionnaire [12 (link)], and a VAS toward subjective impairment of hyposmia in quality of life. Our VAS consisted of an 11-point scale ranging between 0 and 10, being “not a problem” on the left end of the scale (number 0) and “worst problem in my life” on the right end of the scale (number 10). An objective assessment of olfactory thresholds using the Sniffin´ Sticks threshold test with n-butanol: 16 levels in 48 pens were also performed [13 (link)]. The nasal status assessment was performed by nasal endoscopy for exclusion of nasal pathology and evaluation of Lund-Kennedy score - when a polyp score ≥ 1 was seen, the patient was excluded from our cohort while follow-up and further management were maintained in parallel. Also, all patients underwent olfactory training and adjuvant therapy using the strategy described in the protocol described by Sousa et al. [14 (link)].
Variables evaluated
Age, gender, relevant comorbidities, date of perceived onset of OD, olfactory thresholds, and VAS (related to OD). Patients were re-evaluated after three months, and data was collected.
Statistical analysis
Collected data were analyzed using SPSS version 26 (Statistical Package for Social Studies) - IBM, USA. For numerical values, the range, mean, and standard deviations were calculated. The differences between the two mean values were used using the Mann-Whitney U test. Differences in mean values before and after the intervention were done by Wilcoxon signed ranks test. The correlation between VAS and olfactory thresholds was done using Pearson’s correlation coefficient. To access the confounding variables, ANCOVA analysis was also performed. All reported p-values are two-tailed, with a p-value ≤ 0.05 indicating statistical significance.
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