Pneumonia immunization in older adults: review of vaccine effectiveness and strategies

Usama Assaad,2 Ibrahim El-Masri,2 Jahan Porhomayon,1,3 Ali A El-Solh1–41The Veterans Affairs Western New York Healthcare System, Buffalo, NY, USA; 2Division of Pulmonary, Critical Care, and Sleep Medicine, 3Department of Anesthesia, 4Department of Social and Preventive Medicine, State University of New York at Buffalo School of Medicine and Biomedical Sciences and School of Public Health and Health Professions, Buffalo, NY, USAAbstract: Vaccination remains the primary preventive strategy in the elderly against Streptococcus pneumoniae and influenza infections. The effectiveness of this strategy in preventing pneumonia has been in doubt despite the increase in vaccination coverage among older adults. Randomized controlled trials (RCTs) and observational studies aimed at determining clinical outcomes and immune response following pneumococcal vaccination have yielded conflicting results. The protective efficacy of pneumococcal vaccination against pneumonia in older adults has not been firmly established due to a lack of RCTs specifically examining patients ≥ 65 years of age. Similarly, the reported benefits of influenza vaccination have been derived from observational data. The assessment of clinical benefit from influenza vaccination in the elderly population is complicated by varying cohorts, virulence of the influenza strain, and matching of vaccine and circulating viral strains. The presence of selection bias and use of nonspecific end points in these studies make the current evidence inconclusive in terms of overall benefit. The development of more immunogenic vaccines through new formulations or addition of adjuvants holds the promise of revolutionizing delivery and improving efficacy. Dismantling existing barriers through education, providing technology assistance predominantly to developing countries, and establishing clear regulatory guidance on pathways for approval are necessary to ensure timely production and equitable distribution.Keywords: pneumococcal vaccine, influenza vaccine, vaccine effectiveness, pneumonia, older adult

A clinical trial of volume- versus pressure-controlled intraoperative ventilation during laparoscopic bariatric surgeries

Background: Intra-operative ventilation is often challenging in patients with morbid obesity undergoing bariatric surgery. Objectives: To test the noninferiority of pressure-controlled ventilation (PCV) to volume-controlled ventilation (VCV) in respiratory mechanics. Setting: Bariatric Surgery Center, Iran. Methods: In a randomized open-labeled clinical trial, 66 individuals with morbid obesity undergoing laparoscopic bariatric surgeries underwent intraoperative ventilation with either PCV or VCV. The measurements taken were peak and mean airway pressures (H2O), partial pressure of arterial oxygen (PaO2), partial pressure of arterial carbon dioxide (PaCO2) and end-tidal carbon dioxide (CO2). We additionally collected pulse-oximetric oxygen saturation, inspiratory concentration of oxygen (FiO2), and hemodynamic variables. Data were analyzed with repeated measures over the time of intubation, after peritoneal insufflation, and every 15 minutes, thereafter up to one hour. Results: PCV mode was successful to sustain adequate ventilation in 97 of the patients, which was similar to the 94 success rate of the VCV mode. Peak airway pressure increased 6 cmH2O and end-tidal CO2 rose by 5 mm Hg after abdominal insufflation in both groups (P = .850 and .376). Alveolar-arterial oxygen gradient similarly increased within 30 minutes after tracheal intubation both in PCV and VCV groups, with small trend of being higher in the VCV group. The ratio of dead space to tidal volumes (VD/VT) did not have a meaningful change (P = .724). Conclusion: PCV was noninferior to VCV during laparoscopic bariatric surgery. Either mode of ventilation could be alternatively used during the anesthesia care of these patients. © 2020 American Society for Bariatric Surger