Posterior vitreous detachment is a fairly common condition in elderly people. Tractions exerted by the detached vitreous on the retina may result in retinal tears and detachments. We studied how these tractions can arise from saccadic eye movements. Numerical simulations have been performed on a two-dimensional model of the vitreous chamber within a rigid spherical sclera, subjected to prescribed finite-amplitude rotations about a vertical axis. The vitreous chamber was assumed to be split into two regions: one occupied by the detached vitreous, modeled as an elastic viscous solid, and the other occupied by the separated liquefied vitreous, modeled as a Newtonian fluid. At the interface between the two phases, we also considered the presence of the vitreous cortex, modeled as an elastic membrane. We tested several different configurations of the interface. In all cases, we found that eye rotations generate large tractions on the retina close to the attachment points of the membrane. Comparing them, we identified configurations of the vitreous detachment that exhibit higher tractions. We also investigated how the response to saccadic movements depends on some physical parameters, in particular on the rheological properties of the solid phase and the membrane. The numerical simulations show that the generated tractions may be of the same order of magnitude as the adhesive force between the retina and the pigment epithelium. Therefore, the model provides a sound physical justification for the hypothesis that saccadic movements, in the presence of posterior vitreous detachment, could be responsible for high tractions on the retina, which may trigger retinal tear formation.

Context The influence of the gonadal hormones on some aspects of the human physiology has been studied with uncertain results. Still a confusion exists in relation to the real effects of the female hormones on the perception of pain. The existing data refer mainly to experimental studies and have provided results not always useful in the clinical practice. Data source This study was designed to detect whether there are differences in the perception of the postoperative pain in women, during two clearly defined phases of hormonal asset: luteal and follicular phases. Conclusion The results of this study have demonstrated that in postoperative female patients pain is perceived significantly more in the luteal phase of the menstrual period, than in the follicular phase. This could suggest that female in child‐bearing age should be scheduled for elective surgery preferentially during the follicular phase, unless differently necessary. It would guarantee a more comfortable postoperative period, with reduced necessity of analgesics.

Painful rib fractures may be a factor in trauma patients remaining intubated and being given postoperative mechanical ventilation after emergency surgery. Regional techniques could provide sufficient analgesia in these patients to enable weaning and extubation and thus prevent or minimize complications related to prolonged ventilatory support. We describe a trauma patient with multiple rib fractures requiring an emergency splenectomy for whom an ultrasound-guided serratus plane block provided good quality pain relief for his rib fractures and enabled fast-track extubation in the operating room.

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