Physiological Effects of Sildenafil Versus Placebo at High Altitude: A Systematic Review.

Poudel, Sangeeta, Sandesh Gautam, Purushottam Adhikari, and Ken Zafren. Physiological effects of sildenafil versus placebo at high altitude: a systematic review. High Alt Med Biol. 25:16-25, 2024. Introduction: High altitude pulmonary edema (HAPE), a life-threatening condition that affects individuals ascending to high altitude, requires the development of pulmonary hypertension. Sildenafil can be used to prevent and treat HAPE, presumably by decreasing pulmonary artery pressure (PaP). We compared the physiological effects of sildenafil versus placebo at high altitude (above 2,500 m), including the effects on PaP. Methods: We performed a systematic search of PubMed, EMBASE, and Cochrane CENTRAL for randomized controlled studies of the physiological effects of sildenafil in hypoxia in healthy individuals. We conducted a systematic review of all studies meeting our criteria. Results: Of the 14 studies that met the inclusion criteria, 8 were hypobaric hypoxia studies. Six studies reported data at rest at altitudes from 3,650 to 5,245 m. Two were simulations reporting exercise data at equivalent altitudes of 2,750-5,000 m. Nine studies used normobaric hypoxia corresponding to altitudes between 2,500 and 6,400 m. One reported only rest data, two reported rest and exercise data, and the others reported only exercise data. Sildenafil significantly reduced PaP at rest and exercise in hypobaric or normobaric hypoxia. There were no significant differences between arterial oxygen saturation (SpO2) with sildenafil in hypobaric or normobaric hypoxia at rest or exercise. There were no significant differences in heart rate or mean arterial pressure (MAP) at rest or exercise and cardiac output during exercise in hypobaric or normobaric hypoxia. Conclusions: Sildenafil significantly reduces PaP at rest and exercise in normobaric or hypobaric hypoxia. Sildenafil has no significant effects on SpO2, heart rate, cardiac output (during exercise), or MAP at rest or exercise in hypobaric or normobaric hypoxia.

Prevalence of Loss of Smell and Loss of Taste in COVID-19 Infected Patients.

BACKGROUND: The clinical presentations of COVID-19 have been variable, with atypical presentations being reported worldwide. Different studies have shown that olfactory and gustatory symptoms are present in confirmed COVID-19 cases, who may not have had other nasal complaints earlier. The high prevalence of these symptoms, exhibiting olfactory dysfunction before the appearance of others, is a relevant finding to aid for early detection of COVID-19. In this study, we aim to find out about the prevalence of anosmia and ageusia in COVID-19 and its correlation with age, sex, and severity of disease in the Nepalese population. METHODS: Patients with laboratory-confirmed COVID-19 infection by reverse transcription-polymerase chain reaction (RT-PCR) done at Shukraraaj Tropical and Infectious Disease Hospital, Kathmandu were recruited. Questionnaires based on loss of taste and loss of smell components including age, sex, ethnicity, comorbidities were prepared, and the patients were interviewed retrospectively by phone contact. RESULTS: A total of 300 patients were enrolled in our study. The mean age of the patients was 38.36±14.24 years. Prevalence of loss of smell was 54%(N=162) and loss of taste was 53% (N=159). Both of the symptoms were present in 45% of patients. The severity of the disease has a statistically significant effect on the loss of smell and taste whereas gender and smoking history has no significant difference over it. CONCLUSIONS: More than half of the COVID-19 positive patients in our cohort had either loss of taste or loss of smell with the severity of disease having a significant effect on it.

Quality of reporting web-based and non-web-based survey studies: What authors, reviewers and consumers should consider.

BACKGROUND: Several influential aspects of survey research have been under-investigated and there is a lack of guidance on reporting survey studies, especially web-based projects. In this review, we aim to investigate the reporting practices and quality of both web- and non-web-based survey studies to enhance the quality of reporting medical evidence that is derived from survey studies and to maximize the efficiency of its consumption. METHODS: Reporting practices and quality of 100 random web- and 100 random non-web-based articles published from 2004 to 2016 were assessed using the SUrvey Reporting GuidelinE (SURGE). The CHERRIES guideline was also used to assess the reporting quality of Web-based studies. RESULTS: Our results revealed a potential gap in the reporting of many necessary checklist items in both web-based and non-web-based survey studies including development, description and testing of the questionnaire, the advertisement and administration of the questionnaire, sample representativeness and response rates, incentives, informed consent, and methods of statistical analysis. CONCLUSION: Our findings confirm the presence of major discrepancies in reporting results of survey-based studies. This can be attributed to the lack of availability of updated universal checklists for quality of reporting standards. We have summarized our findings in a table that may serve as a roadmap for future guidelines and checklists, which will hopefully include all types and all aspects of survey research.

Definitions for warning signs and signs of severe dengue according to the WHO 2009 classification: Systematic review of literature.

Since warning signs and signs of severe dengue are defined differently between studies, we conducted a systematic review on how researchers defined these signs. We conducted an electronic search in Scopus to identify relevant articles, using key words including dengue, "warning signs," "severe dengue," and "classification." A total of 491 articles were identified through this search strategy and were subsequently screened by 2 independent reviewers for definitions of any of the warning or severe signs in the 2009 WHO dengue classification. We included all original articles published in English after 2009, classifying dengue by the 2009 WHO classification or providing the additional definition or criterion of warning signs and severity (besides the information of 2009 WHO). Analysis of the extracted data from 44 articles showed wide variations among definitions and cutoff values used by physicians to classify patients diagnosed with dengue infection. The establishment of clear definitions for warning signs and severity is essential to prevent unnecessary hospitalization and harmonizing the interpretation and comparability of epidemiological studies dedicated to dengue infection.