Intravenous Lidocaine for the Prevention of Postoperative Catheter-Related Bladder Discomfort in Male Patients Undergoing Transurethral Resection of Bladder Tumors: A Randomized, Double-Blind, Controlled Trial.

BACKGROUND: Male patients undergoing transurethral resection of bladder tumors (TURBT) are prone to suffer from catheter-related bladder discomfort (CRBD). Lidocaine administration has been widely performed to reduce postoperative pain. Here, the effect of intravenous lidocaine administration on moderate-to-severe CRBD was evaluated in male patients undergoing TURBT. METHODS: Patients were randomly allocated to receive intravenous lidocaine (1.5 mg/kg bolus dose followed by a 2 mg/kg/h continuous infusion during the intraoperative period, which was continued for 1 hour postsurgery; group L) or placebo (normal saline; group C). The primary outcome was moderate-to-severe CRBD at 0 hour postsurgery (on admission to the postanesthetic care unit), analyzed using the χ test. The secondary outcome was opioid requirement during the 24-hour postoperative period. None, mild, and moderate-to-severe CRBD at 1, 2, and 6 hours postsurgery, postoperative pain, patient satisfaction, side effects of lidocaine and rescue medications (tramadol and fentanyl), and surgical complications were also assessed. RESULTS: A total of 132 patients were included in the study (66 patients in each group). The incidence of moderate-to-severe CRBD at 0 hour postsurgery was significantly lower in group L than in group C (25.8% vs 66.7%, P < .001, relative risk: 0.386, 95% confidence interval: 0.248-0.602). Opioid requirements during the 24-hour postoperative period were significantly lower in group L than in group C (10.0 mg [interquartile range (IQR), 5.0-15.0 mg] vs 13.8 mg [IQR, 10.0-20.0 mg], P = .005). At 1 and 2 hours postsurgery (but not at 6 hours), the incidence of moderate-to-severe CRBD was significantly lower in group L than in group C (1 hour: 10.6% vs 27.3%, P = .026; 2 hours: 0.0% vs 15.2%, P = .003). Patient satisfaction was significantly greater in group L than in group C (5.0 [IQR, 4.8-6.0] vs 4.0 [IQR, 4.0-5.0], P < .001). No lidocaine-related side effects were reported. Rescue medication-related side effects and surgical complications did not differ significantly between the 2 groups. CONCLUSIONS: Intravenous lidocaine administration resulted in lower incidence of moderate-to-severe CRBD, lower opioid requirement, and higher patient satisfaction in male patients undergoing TURBT without evidence of significant side effects.

Characterization of protein-immobilized polystyrene nanoparticles using impedance spectroscopy.

A novel approach for characterization of non-conductive protein-immobilized nanoparticles using AC impedance spectroscopy combined with conductive atomic force microscopy was examined. As AC impedance spectroscopy can provide information on diverse electrical properties such as capacitance and inductance, it is applicable to the characterization of non-conductive substances. Several non-conductive protein-immobilized polystyrene nanoparticles were analyzed using AC impedance spectroscopy, and their impedance spectra were used as markers for nanoparticle identification. Analyses of impedance signals using an electrical circuit model established that the capacitance and inductance of each nanoparticle changed with the adsorbed protein and that impedance spectral differences were characteristic properties of the proteins. From this study, AC impedance spectroscopy was shown to be a useful tool for characterization of non-conductive nanoparticles and is expected to be applicable to the development of sensors for nanomaterials.

Simultaneous mineralization and deposition of inorganic nanoparticles onto micropatterns with a perfluoropolyether-decorated surface as a passivating layer.

We achieved simultaneous mineralization and patterning of inorganic nanoparticles on micropatterns using peptide as a linker and perfluoropolyether (PFPE) as a passivating molecule. The peptide was used as a linker molecule immobilizing inorganic nanoparticles on the substrate and PFPE was exploited as a mask material preventing nanoparticle binding. These two substances were used as surface-modifying molecules for the positive and negative patterns, respectively. On the patterned surface, mineralization and selective deposition of inorganic nanoparticles (such as TiO2 and Cu2S) were achieved by exploiting the characteristics of the surface-modifying molecules. The aqueous precursors of inorganic sources were mineralized to the nanoparticles, and the mineralized nanoparticles were bound directly to the peptide-decorated positive pattern, while their deposition on the negative pattern was repelled because of the low surface energy of PFPE. The nanoparticle-bound surface was identified by making a sandwich structure with a fluorescece-decorated peptide and observing the surface topology. The nanoparticle layers retained their inherent electrical properties, suggesting potential applications in micro device fabrication. This study demonstrates that selective deposition of metallic and inorganic nanoparticles can be achieved with the use of PFPE and reactive peptides while keeping the original characteristics of the nanoparticles.

Comparison between total intravenous anesthesia and balanced anesthesia on postoperative opioid consumption in patients who underwent laparoscopic-assisted distal gastrectomy.

Remifentanil is the most frequently prescribed opioid for total intravenous anesthesia (TIVA) or balanced anesthesia (BA), due to its favorable pharmacological properties. However, several studies have reported opioid-induced hyperalgesia and/or acute tolerance after intraoperatively using remifentanil. In addition, it is imperative to control postoperative pain with lower doses of opioid anesthetic agents. Therefore, we compared the amount of opioid consumption between TIVA with propofol-remifentanil and BA with desflurane-remifentanil, to control postoperative pain in patients who underwent laparoscopic-assisted distal gastrectomy (LADG) with gastroduodenostomy.We retrospectively evaluated demographic variables (age, gender, height, weight, and smoking habits), the duration of general anesthesia (GA), and intraoperatively administered remifentanil consumption through the electronic medical records of patients who underwent LADG with gastroduodenostomy due to early stomach cancer. The primary outcome was postoperative opioid consumption during postoperative day (POD) 2. The secondary outcomes were the incidence of any rescue opioid analgesics administered, numeric rating scale, and various adverse effects during POD 2. We categorized the data in 2 patient groups to compare TIVA with propofol-remifentanil (TIVA group) to BA with desflurane-remifentanil (BA group) on the postoperative opioid analgesic consumption.We divided 114 patients into the TIVA (46 patients) and BA (68 patients) groups. Opioid consumption as a primary outcome was significantly higher in the BA group than in the TIVA group during POD 2 except in the post-anesthesia care unit. The cumulative opioid consumption was significantly higher in the BA than in the TIVA group. The incidence of rescue analgesic at POD 2 was higher in the BA than in the TIVA group. In the TIVA group, remifentanil consumption was higher, and the duration of GA was shorter than that in the BA group. No statistically significant differences were observed when comparing other variables.Our results indicated that the maintenance of GA with TIVA (propofol-remifentanil) reduces opioid consumption for postoperative pain control compared to BA (desflurane-remifentanil) in patients undergoing LADG with gastroduodenostomy.

Does Erector Spinae Plane Block Have a Visceral Analgesic Effect?: A Randomized Controlled Trial.

The visceral analgesic efficacy of erector spinae plane block (ESPB) is still a matter of debate. This study attempted to investigate the visceral analgesic efficacy of ESPB in clinical setting. After randomized, we performed ultrasound-guided bilateral rectus sheath block (RSB), which was aimed to prevent postoperative somatic pain on all patients who underwent laparoscopic cholecystectomy (LC). Ultrasound-guided bilateral ESPB at T7 level was performed only to the intervention group to provide the visceral analgesic block. The intraoperative requirement for remifentanil (P = 0.021) and the cumulative fentanyl consumption at postoperative 24-hours was significantly lower in the ESPB group (206.5 ± 82.8 µg vs.283.7 ± 102.4 µg, respectively; P = 0.004) compared to non-ESPB group. The ESPB group consistently showed lower accumulated analgesic consumption compared with those in the non-ESPB group at all observed time-points (all P < 0.05) after 2 hours and the degree of the accumulated analgesic consumption reduction was greater (P = 0.04) during the 24-hour postoperative period. Pain severity was lower in the ESPB group at 6-hours postoperatively. The significantly reduced opioid consumption in ESPB group may imply that while preliminary and in need of confirmation, ESPB has potential visceral analgesic effect. Therefore, performing ESPB solely may be feasible in inducing both somatic and visceral analgesia.

Use of the self-assembly of tyrosine-containing bolaamphiphile molecules as a reactive template for metal deposition.

A novel bolaamphiphile molecule exploiting biochemical functionality was synthesized and self-assembled to form a spherical reactive template for the preparation of composite metallic nanoshells. A tyrosine-containing bolaamphiphile, bis(N-alpha-amido-tyrosine)-1,7-heptane dicarboxylate, self-assembles instantaneously in an aqueous solution forming nanoscaled spheres. Instantaneous assembly of the prepared bolaamphiphile is driven by the polarity and stacking of phenol moiety in tyrosine. Through spectroscopic investigations, molecular interactions such as hydrogen bonding and π-π stacking of aromatic rings were found to induce the self-assembly of the molecule. The phenol moiety of tyrosine is exposed to the surface of the spherical assembly due to its polarity. Under basic conditions, the spherical assembly was used as a reactive template on which metal clusters were deposited. The surface-exposed phenol group reduced the silver ions to solid clusters, and these clusters were further exploited as catalysts for the gold layer deposition. This study illustrates that the bolaamphiphilic molecule with designed biochemical functionality provides a facile way to prepare supramolecular structures with chemical activity.