The impact of ultrasound-guided erector spinae plane block on hemodynamic stability and postoperative pain in patients undergoing modified radical mastectomy for breast cancer.

OBJECTIVE: Breast cancer, a prevalent global malignancy in women, necessitates a comprehensive treatment approach, with surgery playing a crucial role. Severe acute pain is common post-radical breast cancer surgery, emphasizing the significance of hemodynamic stability and postoperative pain control for optimal outcomes. This study evaluates the impact of ultrasound-guided erector spinae plane block (ESPB) on these parameters in ASA scores 1-2 patients undergoing modified radical breast cancer surgery with general anesthesia. PATIENTS AND METHODS: Forty-eight patients were divided into two groups: a general anesthesia group, with erector spinae plane block (GA+ESPB), and a control group receiving only general anesthesia (GA). Hemodynamic parameters were continuously monitored, and postoperative pain was assessed using the visual analog scale (VAS) at various time points. RESULTS: Ultrasound-guided ESPB effectively maintained hemodynamic stability and reduced postoperative pain in breast cancer surgery patients. Statistically significant differences were observed in heart rate, systolic and diastolic blood pressure, and mean arterial pressure between the GA and GA+ESPB groups at multiple time points (p < 0.05). VAS scores showed a significant interaction time*group (p < 0.001), with consistent differences between the groups at all time points (p ≤ 0.001). CONCLUSIONS: Ultrasound-guided ESPB application proved effective in preserving hemodynamic stability and managing postoperative pain in modified radical breast cancer surgery. The technique demonstrates promise in minimizing complications related to hemodynamic variations and postoperative pain, contributing to a comprehensive approach to breast cancer surgical treatment.

Interplay of model ingredients affecting aggregate shape plasticity in diffusion-limited aggregation.

We analyze the combined effect of three ingredients of an aggregation model--surface tension, particle flow and particle source--representing typical characteristics of many aggregation growth processes in nature. Through extensive numerical experiments and for different underlying lattice structures we demonstrate that the location of incoming particles and their preferential direction of flow can significantly affect the resulting general shape of the aggregate, while the surface tension controls the surface roughness. Combining all three ingredients increases the aggregate shape plasticity, yielding a wider spectrum of shapes as compared to earlier works that analyzed these ingredients separately. Our results indicate that the considered combination of effects is fundamental for modeling the polymorphic growth of a wide variety of structures in confined geometries and/or in the presence of external fields, such as rocks, crystals, corals, and biominerals.

Fractal analysis of retinal vessel patterns in ophthalmically normal dogs.

OBJECTIVE: To study the applicability of the fractal dimension as a parameter for describing retinal vessel patterns in ophthalmically normal dogs. PROCEDURES: The following strategy was adopted: (i) development of an experimental procedure to obtain digitalized photographs of the fundus; (ii) development of software to segment retinal vessel images and calculate the box-counting and radius of gyration fractal dimensions of the retinal vessels and diffusion-limited aggregation (DLA), a process with similar characteristics to retinal vessel morphology, and (iii) establishment of a standard curve for the fractal dimensions of segmented vessels. RESULTS: Digitalized photographs of the fundus showed an adequate contrast between the vessels and the rest of the fundus for numerical analysis. The software developed produced a binary image of the retinal vessels permitting calculation of the fractal dimension. The mean values of the fractal dimensions calculated by the methods of box-counting and radius of gyration for the DLA were significantly different (t = -40.33, P approximately 0). The radius of gyration method was found to be more suitable for documenting the dimension of the DLA and, consequently, of the dog's retinal vessels. CONCLUSION: This methodology may be useful to differentiate between normal and pathologic states of canine retinal vascularization.

Can a patient be successfully prepared for pheochromocytoma surgery in three days? A case report.

The case of a patient who insisted on urgent surgical removal of a pheochromocytoma is presented. Rapid preparation started with continuous infusion of urapidil 3 days before surgery. On the evening before the operation, an additional infusion of magnesium sulphate was started. The target of preoperative optimization was to maintain blood pressure <140/90 mm Hg and heart rate <100 beats min(-l). Anesthesia was induced with fentanyl, propofol and rocuronium and maintained with sevoflurane in 100% oxygen and continuous infusion of fentanyl. Hypertensive events were treated by continuous infusions of urapidil and magnesium sulphate. Just before tumor resection, additional boluses of urapidil and MgSO4 were administered; both fentanyl infusion and end tidal concentration of sevoflurane were increased. Blood pressure was well maintained through the anesthesia; no transient periods of hypotension after tumor removal were observed. The patient's peroperative course was uneventful. He was discharged home without antihypertensive medication on the 5th postoperative day. This case demonstrates that with urapidil and magnesium sulphate administration rapid preparation for pheochromocytoma resection can be successfully achieved within 3 days.