Ultraviolet Resonant Raman Scattering of Electrolyte Solutions.

Saltwater stands as the most prevalent liquid on Earth. Consequently, substantial interest has been directed toward its characterization, both as an independent system and as a solvent for complex structures such as biomacromolecules. In the last few decades, special emphasis was placed on the investigation of the hydration properties of ions for the fundamental role they play in numerous chemical processes. In this study, we employed multi-wavelength Raman spectroscopy to examine the hydration shell surrounding bromide ions in solutions of simple electrolytes, specifically lithium bromide, potassium bromide, and cesium bromide, at two different concentrations. Cation-induced differences among electrolytes were observed in connection to their tendency to form ion pairs. An increased sensitivity to reveal the structure of the first hydration shell was evidenced when employing ultraviolet excitation in the 228-266 nm range, under resonance conditions with the charge transfer transition to the solvent peaked at about 200 nm. Other than a significant increase in the Raman cross-section for the OH stretching band when shifting from pure water to the solution, a larger enhancement for the Raman signal of the H-O-H bending mode over the stretching vibration was observed. Thus, the bending band plays a crucial role in monitoring the H-bond structure of water around the anions related to the charge distribution within the first hydration shell of anions, being an effective probe of hydration phenomena.

Pseudo-tunneling procedure for PICC-ports catheters insertion in patients with small veins at the middle third of the arm.

BACKGROUND: Axillary vein in the brachial tract or Basilic vein in the proximal third of the arm usually present a diameter wide enough to receive a catheter of 5 Fr. Therefore, a peripherally inserted central catheters with port (PICC-Ports) cannot be positioned in these areas. Pseudo-tunneling procedure allows the positioning of the Port in the middle part of the arm without using tunnelers during insertion of PICC with Port in patients who present deep veins of the arm too small to receive a PICC-Port catheter. The aim of this study was to present our experience with pseudo-tunneling procedure during the positioning of the PICC-Port, while using a particular variation of the technique already described for PICCs and midline. METHODS: From January to December 2023, 103 PICC-Ports were placed in adult patients. Ninety catheters were tunneled from the puncture of the axillary vein at the proximal arm point, while we used this new technique in 42 patients by the same trained team of Vascular Access Unit at ASST Spedali Civili Hospital of Brescia. RESULTS: All procedures were successfully performed at the first attempt. No insertion related complications were observed. CONCLUSIONS: Our data suggest pseudo-tunnelling is a safe and effective technique for PICC-Ports insertion avoiding central venous catheterization, even in patient with small vein at the arms.

Guidewire replacement of valved tunneled-cuffed silicone catheters with power injectable polyurethane tunneled-cuffed catheters or with ports.

BACKGROUND: Silicone Cuffed Centrally Inserted Central venous catheters (CICCs) were a type of catheters that have been used for a long time especially in cancer patients. Recently, thanks to biomedic research progresses, polyurethane catheters have resulted in higher surgical performances compared to classical silicone ones. Indeed, the inferior calibers of these new catheters lead to an extremely faster infusion rate. The presence of a valve at the tip of the catheter could suggest an impossible replacement procedure over a Seldinger guidewire. METHOD: The aim of this article is to explain our replacement technique over guidewire of silicone cuffed and valved tunneled CICCs with a power injectable polyurethane cuffed tunneled CICC. The casistic presented was evaluated at the Vascular Access Unit of ASST Spedali Civili in Brescia, Italy. The study involved 35 successful catheter replacement over guidewire, meanwhile cases where patients presented sepsis, exit site infection, or catheter damage were premeditatedly excluded. RESULTS: The maneuver was always conducted following the same procedure without noticing particular complications associated with CICC insertion. Indeed, the operation was quick, feasible, and safe. Septic, thromboembolic, or hemorrhagic complications also related to patients presenting dysfunctional coagulation cascade were not encountered. CONCLUSIONS: Our experience regarding the replacement technique of silicone cuffed and valved catheters over guidewire was considered feasible, accurate, and efficient for all patients treated, even in those presenting thrombocytopenia or a dysfunctional coagulation cascade.

How to remove a tunneled and cuffed central venous catheter quickly and safely? A little trick useful in children.

BACKGROUND: The aim of this study was to present our experience with a use of own variation of the traditional technique for tunneled and cuffed catheters removal. METHODS: From July 2021 to March 2023, 110 tunneled cuffed centrally inserted central catheters (CICCs) were removed at the Vascular Access Unit of ASST Spedali Civili of Brescia using our particular technique; pediatric patients were 15 admitted to "Children Hospital" of Brescia. The catheter is cut with its adhesions above the cuff and then pulled out. The cuff is then removed with all adhesions attached. RESULTS: Each procedure was successfully performed to the end with local anesthesia, also in younger children. The maneuver was very short and well tolerated. No related complications were observed. The maneuver has always been considered easy even by less experienced surgeons. The scars were aesthetically good and well accepted by the patients. CONCLUSIONS: The technique described has the advantage of not requiring the careful lysis of the adherence from the cuff. If the procedure is quick it can be performed without general anesthesia and without significant psychological trauma also in less compliant children. The skin cut very short leaves an almost invisible scar. It is another notable advantage especially for young girls.

Guidewire replacement of tunneled central venous catheters in children reusing the same subcutaneous route.

BACKGROUND: Tunneled centrally inserted central venous catheters (CICCs) are a type of catheters used especially in cancer pediatric patients or affected from short bowel disease and malabsorption. Recently, thanks to biomedical research progresses, polyurethane catheters have resulted in high surgical performances with a low caliber but extremely fast infusion rate. Sometimes the replacement procedure over a Seldinger guidewire could be an appreciable technique especially reusing the same vein and the same tunnel of the previous catheter, with local anesthesia. The aim of this article was to explain our replacement technique over guidewire of tunneled CICCs on pediatric patients. METHODS: The casuistry presented was evaluated at the Unit of Vascular Access of ASST Spedali Civili in Brescia, Italy. The study involved 7 successful catheter replacement over guidewire, meanwhile cases where patients presented sepsis, exit site infection or catheter damage were premeditatedly excluded. Three of them were tunneled and cuffed. Five catheters were in brachiocephalic vein and 2 in internal jugular vein. RESULTS: Every procedure was ended without complications. Of seven patients, five of them underwent to the procedure only with local anesthesia and 2 patients require premedication with Midazolam. No one required general anesthesia. The maneuver was always conducted following the same procedure without noticing particular complications associated with CICC insertion. Indeed, the operation was quick, feasible and safe. Septic, thromboembolic, or hemorrhagic complications also related to patients presenting dysfunctional coagulation cascade were not encountered. CONCLUSIONS: Our experience regarding the replacement technique of tunneled catheters over guidewire was considered feasible, accurate and efficient for all patients treated, even in those presenting thrombocytopenia or dysfunctional coagulation cascade.