Additional file 1: of Working hours and self-rated health over 7Â years: gender differences in a Korean longitudinal study

Directed acyclic graph illustrating the hypothesized pathway of working hours to self-rated health and associated covariates. (PDF 81 kb

Effect of Positive End-Expiratory Pressure on the Sonographic Optic Nerve Sheath Diameter as a Surrogate for Intracranial Pressure during Robot-Assisted Laparoscopic Prostatectomy: A Randomized Controlled Trial

<div><p>Background</p><p>Positive end-expiratory pressure (PEEP) can increase intracranial pressure. Pneumoperitoneum and the Trendelenburg position are associated with an increased intracranial pressure. We investigated whether PEEP ventilation could additionally influence the sonographic optic nerve sheath diameter as a surrogate for intracranial pressure during pneumoperitoneum combined with the Trendelenburg position in patients undergoing robot-assisted laparoscopic prostatectomy.</p><p>Methods</p><p>After anesthetic induction, 38 patients were randomly allocated to a low tidal volume ventilation (8 ml/kg) without PEEP group (zero end-expiratory pressure [ZEEP] group, n = 19) or low tidal volume ventilation with 8 cmH₂O PEEP group (PEEP group, n = 19). The sonographic optic nerve sheath diameter was measured prior to skin incision, 5 min and 30 min after pneumoperitoneum and the Trendelenburg position, and at the end of surgery. The study endpoint was the difference in the sonographic optic nerve sheath diameter 5 min after pneumoperitoneum and the Trendelenburg position between the ZEEP and PEEP groups.</p><p>Results</p><p>Optic nerve sheath diameters 5 min after pneumoperitoneum and the Trendelenburg position did not significantly differ between the groups [least square mean (95% confidence interval); 4.8 (4.6–4.9) mm vs 4.8 (4.7–5.0) mm, P = 0.618]. Optic nerve sheath diameters 30 min after pneumoperitoneum and the Trendelenburg position also did not differ between the groups [least square mean (95% confidence interval); 4.5 (4.3–4.6) mm vs 4.5 (4.4–4.6) mm, P = 0.733].</p><p>Conclusions</p><p>An 8 cmH₂O PEEP application under low tidal volume ventilation does not induce an increase in the optic nerve sheath diameter during pneumoperitoneum combined with the steep Trendelenburg position, suggesting that there might be no detrimental effects of PEEP on the intracranial pressure during robot-assisted laparoscopic prostatectomy.</p><p>Trial Registration</p><p>ClinicalTrial.gov <a href="https://clinicaltrials.gov/ct2/show/NCT02516566" target="_blank">NCT02516566</a></p></div

Variables in the ZEEP and PEEP groups during robot-assisted laparoscopic prostatectomy.

<p>Variables in the ZEEP and PEEP groups during robot-assisted laparoscopic prostatectomy.</p

Sonographic optic nerve sheath diameter in the ZEEP and PEEP groups during robot-assisted laparoscopic prostatectomy.

<p>Sonographic optic nerve sheath diameter in the ZEEP and PEEP groups during robot-assisted laparoscopic prostatectomy.</p

Study flow diagram.

<p>Patients in the zero end-expiratory pressure (ZEEP) group received mechanical ventilation with a tidal volume 8 ml/kg of ideal body weight without positive end-expiratory pressure (PEEP), and those in PEEP group received mechanical ventilation with a tidal volume 8 ml/kg of ideal body weight with 8 cmH₂O PEEP.</p

Demographic data.

<p>Demographic data.</p