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Background General anesthesia may cause atelectasis and deterioration in oxygenation in obese patients. The authors hypothesized that individualized positive end-expiratory pressure (PEEP) improves intraoperative oxygenation and ventilation distribution compared to fixed PEEP. Methods This secondary analysis included all obese patients recruited at University Hospital of Leipzig from the multicenter Protective Intraoperative Ventilation with Higher versus Lower Levels of Positive End-Expiratory Pressure in Obese Patients (PROBESE) trial (n = 42) and likewise all obese patients from a local single-center trial (n = 54). Inclusion criteria for both trials were elective laparoscopic abdominal surgery, body mass index greater than or equal to 35 kg/m2, and Assess Respiratory Risk in Surgical Patients in Catalonia (ARISCAT) score greater than or equal to 26. Patients were randomized to PEEP of 4 cm H2O (n = 19) or a recruitment maneuver followed by PEEP of 12 cm H2O (n = 21) in the PROBESE study. In the single-center study, they were randomized to PEEP of 5 cm H2O (n = 25) or a recruitment maneuver followed by individualized PEEP (n = 25) determined by electrical impedance tomography. Primary endpoint was Pao2/inspiratory oxygen fraction before extubation and secondary endpoints included intraoperative tidal volume distribution to dependent lung and driving pressure. Results Ninety patients were evaluated in three groups after combining the two lower PEEP groups. Median individualized PEEP was 18 (interquartile range, 16 to 22; range, 10 to 26) cm H2O. Pao2/inspiratory oxygen fraction before extubation was 515 (individual PEEP), 370 (fixed PEEP of 12 cm H2O), and 305 (fixed PEEP of 4 to 5 cm H2O) mmHg (difference to individualized PEEP, 145; 95% CI, 91 to 200; P < 0.001 for fixed PEEP of 12 cm H2O and 210; 95% CI, 164 to 257; P < 0.001 for fixed PEEP of 4 to 5 cm H2O). Intraoperative tidal volume in the dependent lung areas was 43.9% (individualized PEEP), 25.9% (fixed PEEP of 12 cm H2O) and 26.8% (fixed PEEP of 4 to 5 cm H2O) (difference to individualized PEEP: 18.0%; 95% CI, 8.0 to 20.7; P < 0.001 for fixed PEEP of 12 cm H2O and 17.1%; 95% CI, 10.0 to 20.6; P < 0.001 for fixed PEEP of 4 to 5 cm H2O). Mean intraoperative driving pressure was 9.8 cm H2O (individualized PEEP), 14.4 cm H2O (fixed PEEP of 12 cm H2O), and 18.8 cm H2O (fixed PEEP of 4 to 5 cm H2O), P < 0.001. Conclusions This secondary analysis of obese patients undergoing laparoscopic surgery found better oxygenation, lower driving pressures, and redistribution of ventilation toward dependent lung areas measured by electrical impedance tomography using individualized PEEP. The impact on patient outcome remains unclear. Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New

BACKGROUND There is an unmet need to improve the HBV vaccination status in patients with chronic liver diseases. Primary care physicians and outpatient hepatologists often fail to vaccinate as recommended. Thus, new strategies to improve the HBV vaccination rate are required. MATERIAL AND METHODS This study was performed in a cohort of patients with chronic liver diseases evaluated for liver transplantation. Vaccination status was taken from the patients' vaccination cards. HBsAg-, anti-HBc-, and anti-HBs-negative individuals were vaccinated against HBV at hospital discharge, and subsequent outpatient completion of the standard vaccination protocol was recommended in detail in the discharge letter. At months 2 and 8, titer controls were performed, and completion of vaccination was evaluated. RESULTS We prospectively recruited 37 patients. At baseline, the vaccination rate against HBV was 24% (N=9/37), and 3/9 HBV vaccinated patients presented with an anti-HBs-titer10 IU/L. Thus, N=34 were vaccinated with Engerix® or Twinrix®. We evaluated 26/34 patients at month 2 and 10/26 again at month 8. The second vaccine dose was obtained by 21/26 (80%) of the patients seen at month 2, and 9/10 (90%) seen at month 8 obtained the third vaccine dose by primary care physicians or ambulant hepatologists. Only 2 patients presented with an anti-HBs-titer10 IU/L at month 8. CONCLUSIONS Initiation of HBV vaccination during hospitalization and detailed recommendations on subsequent vaccinations in the discharge letter improve previously inadequate vaccination rates in the outpatient setting. Similar measures should be implemented at earlier time points of chronic liver diseases to achieve higher immune response rates.