Risk of dispersion or aerosol generation and infection transmission with nasopharyngeal and oropharyngeal swabs for detection of COVID-19: a systematic review.

OBJECTIVES: SARS-CoV-2-related disease, referred to as COVID-19, has emerged as a global pandemic since December 2019. While there is growing recognition regarding possible airborne transmission, particularly in the setting of aerosol-generating procedures and treatments, whether nasopharyngeal and oropharyngeal swabs for SARS-CoV-2 generate aerosols remains unclear. DESIGN: Systematic review. DATA SOURCES: We searched Ovid MEDLINE and EMBASE up to 3 November 2020. We also searched the China National Knowledge Infrastructure, Chinese Medical Journal Network, medRxiv and ClinicalTrials.gov up to 29 March 2020. ELIGIBILITY CRITERIA: All comparative and non-comparative studies that evaluated dispersion or aerosolisation of viable airborne organisms, or transmission of infection associated with nasopharyngeal or oropharyngeal swab testing. RESULTS: Of 7702 citations, only one study was deemed eligible. Using a dedicated sampling room with negative pressure isolation room, personal protective equipment including N95 or higher masks, strict sterilisation protocols, structured training with standardised collection methods and a structured collection and delivery system, a tertiary care hospital proved a 0% healthcare worker infection rate among eight nurses conducting over 11 000 nasopharyngeal swabs. No studies examining transmissibility with other safety protocols, nor any studies quantifying the risk of aerosol generation with nasopharyngeal or oropharyngeal swabs for detection of SARS-CoV-2, were identified. CONCLUSIONS: There is limited to no published data regarding aerosol generation and risk of transmission with nasopharyngeal and oropharyngeal swabs for the detection of SARS-CoV-2. Field experiments to quantify this risk are warranted. Vigilance in adhering to current standards for infection control is suggested.

Management of Acute Pain From Non-Low Back, Musculoskeletal Injuries : A Systematic Review and Network Meta-analysis of Randomized Trials.

BACKGROUND: Patients and clinicians can choose from several treatment options to address acute pain from non-low back, musculoskeletal injuries. PURPOSE: To assess the comparative effectiveness of outpatient treatments for acute pain from non-low back, musculoskeletal injuries by performing a network meta-analysis of randomized clinical trials (RCTs). DATA SOURCES: MEDLINE, EMBASE, CINAHL, PEDro (Physiotherapy Evidence Database), and Cochrane Central Register of Controlled Trials to 2 January 2020. STUDY SELECTION: Pairs of reviewers independently identified interventional RCTs that enrolled patients presenting with pain of up to 4 weeks' duration from non-low back, musculoskeletal injuries. DATA EXTRACTION: Pairs of reviewers independently extracted data. Certainty of evidence was evaluated by using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach. DATA SYNTHESIS: The 207 eligible studies included 32 959 participants and evaluated 45 therapies. Ninety-nine trials (48%) enrolled populations with diverse musculoskeletal injuries, 59 (29%) included patients with sprains, 13 (6%) with whiplash, and 11 (5%) with muscle strains; the remaining trials included various injuries ranging from nonsurgical fractures to contusions. Topical nonsteroidal anti-inflammatory agents (NSAIDs) proved to have the greatest net benefit, followed by oral NSAIDs and acetaminophen with or without diclofenac. Effects of these agents on pain were modest (around 1 cm on a 10-cm visual analogue scale, approximating the minimal important difference). Regarding opioids, compared with placebo, acetaminophen plus an opioid improved intermediate pain (1 to 7 days) but not immediate pain (≤2 hours), tramadol was ineffective, and opioids increased the risk for gastrointestinal and neurologic harms (all moderate-certainty evidence). LIMITATIONS: Only English-language studies were included. The number of head-to-head comparisons was limited. CONCLUSION: Topical NSAIDs, followed by oral NSAIDs and acetaminophen with or without diclofenac, showed the most convincing and attractive benefit-harm ratio for patients with acute pain from non-low back, musculoskeletal injuries. No opioid achieved benefit greater than that of NSAIDs, and opioids caused the most harms. PRIMARY FUNDING SOURCE: National Safety Council. (PROSPERO: CRD42018094412).

High-flow nasal cannula for acute hypoxemic respiratory failure in patients with COVID-19: systematic reviews of effectiveness and its risks of aerosolization, dispersion, and infection transmission.

PURPOSE: We conducted two World Health Organization-commissioned reviews to inform use of high-flow nasal cannula (HFNC) in patients with coronavirus disease (COVID-19). We synthesized the evidence regarding efficacy and safety (review 1), as well as risks of droplet dispersion, aerosol generation, and associated transmission (review 2) of viral products. SOURCE: Literature searches were performed in Ovid MEDLINE, Embase, Web of Science, Chinese databases, and medRxiv. Review 1: we synthesized results from randomized-controlled trials (RCTs) comparing HFNC to conventional oxygen therapy (COT) in critically ill patients with acute hypoxemic respiratory failure. Review 2: we narratively summarized findings from studies evaluating droplet dispersion, aerosol generation, or infection transmission associated with HFNC. For both reviews, paired reviewers independently conducted screening, data extraction, and risk of bias assessment. We evaluated certainty of evidence using GRADE methodology. PRINCIPAL FINDINGS: No eligible studies included COVID-19 patients. Review 1: 12 RCTs (n = 1,989 patients) provided low-certainty evidence that HFNC may reduce invasive ventilation (relative risk [RR], 0.85; 95% confidence interval [CI], 0.74 to 0.99) and escalation of oxygen therapy (RR, 0.71; 95% CI, 0.51 to 0.98) in patients with respiratory failure. Results provided no support for differences in mortality (moderate certainty), or in-hospital or intensive care length of stay (moderate and low certainty, respectively). Review 2: four studies evaluating droplet dispersion and three evaluating aerosol generation and dispersion provided very low certainty evidence. Two simulation studies and a crossover study showed mixed findings regarding the effect of HFNC on droplet dispersion. Although two simulation studies reported no associated increase in aerosol dispersion, one reported that higher flow rates were associated with increased regions of aerosol density. CONCLUSIONS: High-flow nasal cannula may reduce the need for invasive ventilation and escalation of therapy compared with COT in COVID-19 patients with acute hypoxemic respiratory failure. This benefit must be balanced against the unknown risk of airborne transmission.

RéSUMé: OBJECTIF: Nous avons réalisé deux comptes rendus sur commande de l'Organisation mondiale de la santé pour guider l'utilisation de canules nasales à haut débit (CNHD) chez les patients ayant contracté le coronavirus (COVID-19). Nous avons synthétisé les données probantes concernant leur efficacité et leur innocuité (compte rendu 1), ainsi que les risques de dispersion des gouttelettes, de génération d'aérosols, et de transmission associée d'éléments viraux (compte rendu 2). SOURCE: Des recherches de littérature ont été réalisées dans les bases de données Ovid MEDLINE, Embase, Web of Science, ainsi que dans les bases de données chinoises et medRxiv. Compte rendu 1 : nous avons synthétisé les résultats d'études randomisées contrôlées (ERC) comparant les CNHD à une oxygénothérapie conventionnelle chez des patients en état critique atteints d'insuffisance respiratoire hypoxémique aiguë. Compte rendu 2 : nous avons résumé sous forme narrative les constatations d'études évaluant la dispersion de gouttelettes, la génération d'aérosols ou la transmission infectieuse associées aux CNHD. Pour les deux comptes rendus, des réviseurs appariés ont réalisé la sélection des études, l'extraction des données et l'évaluation du risque de biais de manière indépendante. Nous avons évalué la certitude des données probantes en nous fondant sur la méthodologie GRADE. CONSTATATIONS PRINCIPALES: Aucune étude éligible n'incluait de patients atteints de COVID-19. Compte rendu 1 : 12 ERC (n = 1989 patients) ont fourni des données probantes de certitude faible selon lesquelles les CNHD réduiraient la ventilation invasive (risque relatif [RR], 0,85; intervalle de confiance [IC] 95 %, 0,74 à 0,99) et l'intensification de l'oxygénothérapie (RR, 0,71; IC 95 %, 0,51 à 0,98) chez les patients atteints d'insuffisance respiratoire. Les résultats n'ont pas démontré de différences en matière de mortalité (certitude modérée), ni de durée du séjour hospitalier ou à l'unité des soins intensifs (certitude modérée et faible, respectivement). Compte rendu 2 : quatre études évaluant la dispersion de gouttelettes et trois évaluant la génération et la dispersion d'aérosols ont fourni des données probantes de très faible certitude. Deux études de simulation et une étude croisée ont donné des résultats mitigés quant à l'effet des CNHD sur la dispersion des gouttelettes. Bien que deux études de simulation n'aient rapporté aucune augmentation associée concernant la dispersion d'aérosols, l'une a rapporté que des taux de débit plus élevés étaient associés à des régions à densité d'aérosols élevée plus grandes. CONCLUSION: Les canules nasales à haut débit pourraient réduire la nécessité de recourir à la ventilation invasive et l'escalade des traitements par rapport à l'oxygénothérapie conventionnelle chez les patients atteints de COVID-19 souffrant d'insuffisance respiratoire hypoxémique aiguë. Cet avantage doit être soupesé contre le risque inconnu de transmission atmosphérique.

Histopathological characterization of a Cameron lesion.

Cameron lesions are linear erosions located at the neck of a hiatal hernia (HH) in patients with a large HH. The prevalence has been seen in up to 5% of patients with HH who undergo esophagogastroduodenoscopy, and they can be associated with overt gastrointestinal bleeding or anemia. These lesions occur due to vascular compression by the diaphragm in a large sliding HH. Histopathologic changes seen in the biopsy tissue of a Cameron lesion are due to ischemia, but this ischemia is reversible with treatment of HH. The existence of this entity and the histopathologic picture of a Cameron lesion is not well known to pathologists, and therefore, a microscopic picture of a Cameron lesion can be easily confused with ischemic gastritis. Ischemic gastritis is the result of atherosclerosis, usually seen in older people, unrelated to HH, and is not easily reversible. The authors received a gastric biopsy of a hiatal hernia without any associated clinical diagnosis of a Cameron lesion conveyed to the pathologist. This biopsy tissue showed ischemic changes in the gastric mucosa on microscopic examination. Diagnosis of ischemic gastritis was considered but ruled out after the case was discussed with the gastroenterologist. The correct diagnosis was made once the clinical diagnosis of HH with Cameron lesion (ie, a vertical red erosion) was made known to the pathologist. By reporting this case, the authors aim to increase awareness of Cameron lesion among pathologists so that they ask about the presence of a Cameron lesion before making the diagnosis of ischemic gastritis.

Diagnosis and management of mucoepidermoid carcinoma of the lacrimal duct.

Primary tumors of the lacrimal sac are rare, and mucoepidermoid carcinomas of the lacrimal sac have only been reported 13 times in the literature. We reported an intermediate-grade mucoepidermoid carcinoma that was managed with wide local excision, medial maxillectomy, and external beam radiotherapy, and the patient has remained disease-free for 7 years. Orbital exenteration had generally been recommended for these tumors, but newer, more conservative resections along with radiation therapy may be equally effective.

Iron accumulation in the substantia nigra of patients with Alzheimer disease and parkinsonism.

BACKGROUND: Preliminary studies have shown an increase in iron accumulation in the substantia nigra but not in the hippocampus in patients with Parkinson disease without dementia and the reverse in patients with Alzheimer disease (AD) and no parkinsonism. OBJECTIVE: To determine whether iron levels (measured as T2 shortening on magnetic resonance images) are greater in the substantia nigra of patients with AD who have parkinsonism than in those with AD alone. DESIGN: Case-control study. SETTING: Albany Medical College, Albany, New York. PARTICIPANTS: Fifteen patients with only AD (controls) and 18 with AD as well as parkinsonism, aged 56 to 89 years, and with a total Clinical Dementia Rating of 5.0 to 11.5. Patients were selected according to the purity of their disease; patients with a Unified Parkinson's Disease Rating Scale motor score of 15 or greater were considered to have parkinsonism. Main Outcome Measure Area under the curve for short T2 (30 milliseconds) in patients with only AD vs patients with AD who developed parkinsonism. RESULTS: Patients who developed parkinsonism along with their existing dementia had significantly more iron in their substantia nigra than did patients with AD alone (P = .03, 2-sample t test). CONCLUSIONS: Iron accumulation may be a predictor of parkinsonism. The development of parkinsonism during the course of AD appears to be associated with the accumulation of iron, which in turn may contribute to the pathogenesis of neurologic decline.

Better perception of global motion after monocular than after binocular deprivation.

We used random-dot kinematograms to compare the effects of early monocular versus early binocular deprivation on the development of the perception of the direction of global motion. Patients had been visually deprived by a cataract in one or both eyes from birth or later after a history of normal visual experience. The discrimination of direction of global motion was significantly impaired after early visual deprivation. Surprisingly, impairments were significantly worse after early binocular deprivation than after early monocular deprivation, and the sensitive period was very short. The unexpectedly good results after monocular deprivation suggest that the higher centers involved in the integration of global motion profit from input to the nondeprived eye. These findings suggest that beyond the primary visual cortex, competitive interactions between the eyes can give way to collaborative interactions that enable a relative sparing of some visual functions after monocular deprivation.