Background: Coronavirus disease 2019 (COVID-19) is a global pandemic caused by severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2). It has brought tremendous challenges to public health and medical systems around the world. The current strategy for drug repurposing has accumulated some evidence on the use of N-acetylcysteine (NAC) in treating patients with COVID-19. However, the evidence remains debated. Methods: We performed the systematic review and meta-analysis that complies with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Five databases and reference lists were searched from inception to May 14, 2022. Studies evaluating the efficacy of NAC in treating patients with COVID-19 were regarded as eligible. The review was registered prospectively on PROSPERO (CRD42022332791). Results: Of 778 records identified from the preliminary search, four studies were enrolled in the final qualitative review and quantitative meta-analysis. A total of 355 patients were allocated into the NAC group and the control group. The evaluated outcomes included intubation rate, improvement, duration of intensive unit stay and hospital stay and mortality. The pooled results showed nonsignificant differences in intubation rate (OR, 0.55; 95% CI, 0.16-1.89; p = 0.34; I2 = 75%), improvement of oxygenation ([MD], 80.84; 95% CI, -38.16 to 199.84; p = 0.18; I2 = 98%), ICU stay (MD, -0.74; 95% CI, -3.19 to 1.71; p = 0.55; I2 = 95%), hospital stay (MD, -1.05; 95% CI, -3.02 to 0.92; p = 0.30; I2 = 90%), and mortality (OR, 0.58; 95% CI, 0.23-1.45; p = 0.24; I2 = 54%). Subsequent trial sequential analysis (TSA) showed conclusive nonsignificant results for mortality, while the TSA for the other outcomes suggested that a larger sample size is essential. Conclusions: The current evidence reveals NAC is not beneficial for treating patients with COVID- 19 with regard to respiratory outcome, mortality, duration of ICU stay and hospital stay.

Cleft palate is the most common congenital facial deformity and may result in multiple sequelae and disabilities. One common comorbidity is refractory otitis media with effusion (OME), as patients with cleft palate have impaired eustachian tube function with alteration of the nearby muscular structures. Ventilation tube insertion (VTI) is regarded as an effective mean to address OME in addition to palatal repair surgery. However, controversy regarding the efficacy of VTI and the timing of VTI remains. We aimed to assess the efficacy of VTI with palatal repair for cleft palate on OME development via a meta-analysis with systematic review and trial sequential analysis (TSA). Studies including patients with cleft palate who underwent palatal repair with or without VTI were considered eligible. After searching the Cochrane Library, PubMed, EMBASE, Web of Science, Scopus and China National Knowledge Infrastructure (CNKI) from inception through 5 September 2021, 9 studies involving 929 patients were included. Overall, a significantly higher OME-free rate was noted in those who underwent VTI and palatal repair than in those who underwent palatal repair alone (OR, 2.73; 95% CI, 1.37 to 5.42; p = 0.004; I2 = 84%). Subgroup analysis revealed that the OME-free rate remained higher in the concurrent VTI group (OR, 3.29; 95% CI, 1.64 to 6.59; p < 0.001; I2 = 81%). TSA indicated that all the analyses provided conclusive results by meeting the required information size and Z-value. The meta-analysis indicated that VTI is an effective procedure to prevent OME in patients with cleft palate and that VTI is beneficial when performed concurrently with palatal repair surgery.

Acute low-tone hearing loss (ALHL) is a common clinical disease and was first proposed by Abe in 1981 as sensorineural hearing loss confined to low frequencies. The best strategy for initiating medication is still unclear, as the superiority of steroids and diuretics is still debated, and combination therapy might yield additional benefits. However, no study regarding combination therapy has been published. The objective of this study was to evaluate the efficacy of steroid therapy versus combination therapy of diuretics with steroids by conducting a systematic review with a meta-analysis and trial sequential analysis (TSA). Studies enrolling patients with a diagnosis of acute low-tone hearing loss were considered eligible. After searching the PubMed, Cochrane Library, Embase, Scopus and Web of Science databases from inception to 31 December 2021, five studies including 433 patients were enrolled. Overall, the comparison between combination therapy with steroids and diuretics and single-modality treatment with steroids (OR, 1.15; 95% CI, 0.51 to 2.59; p = 0.74; I2 = 34%) and the comparison between combination therapy and treatment with diuretics alone (OR, 1.73; 95% CI, 0.93 to 3.23; p = 0.09; I2 = 5%) showed that combination therapy did not confer significant benefits when compared to single-modality treatments. A trial sequential analysis (TSA) showed conclusive nonsignificant results of the comparison between the combination of steroids and diuretics and a single-modality treatment. In conclusion, we reported that the combination of steroids and diuretics did not yield significant benefits when compared to single-modality treatment with steroids or diuretics. We suggest that treatment should be initiated with steroids or diuretics alone to avoid potential adverse effects.