Apnoeic oxygenation in morbid obesity: a randomised controlled trial comparing facemask and high-flow nasal oxygen delivery.

BACKGROUND: Obesity is a risk factor for airway-related incidents during anaesthesia. High-flow nasal oxygen has been advocated to improve safety in high-risk groups, but its effectiveness in the obese population is uncertain. This study compared the effect of high-flow nasal oxygen and low-flow facemask oxygen delivery on duration of apnoea in morbidly obese patients. METHODS: Morbidly obese patients undergoing bariatric surgery were randomly allocated to receive either high-flow nasal (70 L min-1) or facemask (15 L min-1) oxygen. After induction of anaesthesia, the patients were apnoeic for 18 min or until peripheral oxygen saturation decreased to 92%. RESULTS: Eighty patients were studied (41 High-Flow Nasal Oxygen, 39 Facemask). The median apnoea time was 18 min in both the High-Flow Nasal Oxygen (IQR 18-18 min) and the Facemask (inter-quartile range [IQR], 4.1-18 min) groups. Five patients in the High-Flow Nasal Oxygen group and 14 patients in the Facemask group desaturated to 92% within 18 min. The risk of desaturation was significantly lower in the High-Flow Nasal Oxygen group (hazard ratio=0.27; 95% confidence interval [CI], 0.11-0.65; P=0.007). CONCLUSIONS: In experienced hands, apnoeic oxygenation is possible in morbidly obese patients, and oxygen desaturation did not occur for 18 min in the majority of patients, whether oxygen delivery was high-flow nasal or low-flow facemask. High-flow nasal oxygen may reduce desaturation risk compared with facemask oxygen. Desaturation risk is a more clinically relevant outcome than duration of apnoea. Individual physiological factors are likely to be the primary determinant of risk rather than method of oxygen delivery. CLINICAL TRIAL REGISTRATION: NCT03428256.

Apolipoprotein E Polymorphisms and Parkinson Disease With or Without Dementia: A Meta-Analysis Including 6453 Participants.

A large number of case-control studies have investigated the association of apolipoprotein E ( APOE) polymorphisms with Parkinson disease (PD) and Parkinson disease dementia (PDD), with inconsistent results. This meta-analysis aimed to evaluate the relationship between APOE polymorphisms and PD/PDD risk. We searched for published studies in PubMed, Web of Science, WanFang Data (in Chinese), and CNKI (in Chinese) from inception to June 2017. Case-control studies reporting part or complete APOE genotype and allele frequency data were included. Pooled odds ratios (ORs) with 95% confidence intervals (95% CIs) were calculated using RevMan 5.3 software. A total of 39 studies involving 6453 cases with PD, with 461 cases with PDD, and 6855 controls were included in this meta-analysis. The results showed that the APOE ε3 allele was a protective factor for PD (OR = 0.90, 95% CI: 0.81-0.99; P = .04), whereas no significant differences in PD risk among all cases compared to controls were found for APOE ε2 and ε4. In Asian subgroups, the APOE ε4 allele was shown to be a risk factor for PD (OR = 1.22, 95% CI: 1.01-1.46; P = .04). Additionally, APOE polymorphisms were significantly associated with PDD risk in the entire case group (ε3: OR = 0.72, 95% CI: 0.58-0.89, P = .003; ε4: OR = 1.46, 95% CI: 1.12-1.88, P = .004) and in Asian subgroups.