Oxycodone vs. tramadol in postoperative parent-controlled intravenous analgesia in children: a prospective, randomized, double-blinded, multiple-center clinical trial.

BACKGROUND: Management of acute postoperative pain is one of the major challenges in pediatric patients. Oral oxycodone has shown good pain relief in postoperative pain relief in children, but no studies have investigated intravenous oxycodone in this context. OBJECTIVE: whether oxycodone PCIA can provide adequate and safe postoperative pain relief, in comparison to tramadol as reference opioid drug. DESIGN: a randomized, double-blind, parallel, multi-center clinical trial. SETTING: five university medical centers and three teaching hospitals in China. PARTICIPANTS: patients aged 3-month-old to 6-year-old undergoing elective surgery under general anesthesia. INTERVENTION: patients were randomly allocated to either tramadol (n = 109) or oxycodone (n = 89) as main postoperative opioid analgesic. Tramadol or oxycodone were administered with a loading dose at the end of surgery (1 or 0.1 mg.kg-1, respectively), then with a parent-controlled intravenous device with fixed bolus doses only (0.5 or 0.05 mg.kg-1, respectively), and a 10-min lockout time. OUTCOMES: the primary outcome was adequate postoperative pain relief, defined as a face, legs, activity, cry, and consolability (FLACC) score < 4/10 in the post-anesthesia care unit (PACU), with no need for an alternative rescue analgesia. FLACC was measured 10 min after extubation then every 10 min until discharge from PACU. Analgesia was currently conducted with the boluses of either tramadol or oxycodone if FLACC was ≥ 3, up to three bolus doses, after what rescue alternative analgesia was administered. RESULTS: tramadol and oxycodone provided a similar level of adequate postoperative pain relief in PACU and in the wards. No significant differences were either noted for the raw FLACC scores, the bolus dose demand in PACU, the time between the first bolus dose and discharge from PACU, analgesic drug consumption, bolus times required in the wards, function activity score, or the parents' satisfaction. The main observed side effects in both groups were nausea and vomiting, with no difference between groups. However, patients in the oxycodone group showed less sedation levels and had a shorter stay in the PACU, compared with the tramadol group. CONCLUSIONS: an adequate postoperative analgesia can be achieved with intravenous oxycodone, this with less side effects than tramadol. It can therefore be a choice for postoperative pain relief in pediatric patients. TRIAL REGISTRATION: The study was registered at www.chictr.org.cn (Registration number: ChiCTR1800016372; date of first registration: 28/05/2018; updated date:06/01/2023).

[Three-dimensional printed 316L stainless steel cardiovascular stent's electrolytic polishing and its mechanical properties].

The interventional therapy of vascular stent implantation is a popular treatment method for cardiovascular stenosis and blockage. However, traditional stent manufacturing methods such as laser cutting are complex and cannot easily manufacture complex structures such as bifurcated stents, while three-dimensional (3D) printing technology provides a new method for manufacturing stents with complex structure and personalized designs. In this paper, a cardiovascular stent was designed, and printed using selective laser melting technology and 316L stainless steel powder of 0-10 µm size. Electrolytic polishing was performed to improve the surface quality of the printed vascular stent, and the expansion behavior of the polished stent was assessed by balloon inflation. The results showed that the newly designed cardiovascular stent could be manufactured by 3D printing technology. Electrolytic polishing removed the attached powder and reduced the surface roughness Ra from 1.36 µm to 0.82 µm. The axial shortening rate of the polished bracket was 4.23% when the outside diameter was expanded from 2.42 mm to 3.63 mm under the pressure of the balloon, and the radial rebound rate was 2.48% after unloading. The radial force of polished stent was 8.32 N. The 3D printed vascular stent can remove the surface powder through electrolytic polishing to improve the surface quality, and show good dilatation performance and radial support performance, which provides a reference for the practical application of 3D printed vascular stent.

[Terahertz Spectroscopic Investigation of Substrate Materials for Biological Application in the Frequency Range of 1～15 THz].

As emerging modalities, terahertz time-domain spectroscopy and imaging have been widely applied to investigate the optical properties of different biological tissues. The substrate materials are usually needed for biological spectroscopic measurements. The ultra-broadband and facility in remote sensing of the terahertz air-biased-coherent-detection (ABCD) system mean it is a good potential tool for the spectroscopic study of biological tissues. In this paper, the optical parameters of four typical substrate materials (quartz, high-density polyethylene, teflon and paraffin) are measured using terahertz ABCD spectrometer. The absorption coefficients and refractive indices are presented in the frequency range of 1～15 THz. It is demonstrated that high-density polyethylene and paraffin are good candidates as sample substrate for broadband terahertz biological spectroscopic measurement. However, quartz and teflon which are common substrate materials in narrowband (0.1～3 THz) terahertz system can not be utilized in high terahertz frequency range because they have strong absorption above 5 THz.

Impact of inverse unequal height strut structure on the functional performance of an additively manufactured cardiovascular stent.

Recently, additive manufacturing (AM) has been investigated as an innovative method to manufacture stents due to its capability in producing complex and customized structures. In this paper, the cardiovascular stents of M-type and N-type with inverse unequal height strut structure and N-type with equal height strut structure were designed and manufactured by Selective Laser Melting (SLM). Following surface polishing, balloon expansion, plane compression and three-point bending experiments were carried out to evaluate the mechanical performance of the stent. The stents designed with inverse unequal height strut structure showed higher radial support performance and lower radial recoil when compared to the stents with uniform design. This study proved the feasibility of SLM in rapid manufacturing of cardiovascular stents that can be used for performance evaluation in design stage.

Effects of breakfast with different calorigenic amounts on blood glucose, insulin and glucagon levels.

This study was aimed to investigate the relationship between breakfast and serum glucose, insulin and glucagon concentrations in order to establish a model breakfast appropriate for Chinese. Twenty-four volunteers were randomly assigned to four study groups: high carbohydrate breakfast, high fat and protein breakfast, the typical breakfast and fasting. Each subject had serum and urine samples collected while fasting and at 1,2 and 3.5 hours following the meal. The concentration of serum glucose, insulin and glucagon was measured. The levels of serum glucose in group A, B and C differed significantly at 1 and 2 hour after meal compared to those at fasting (P<0.05). The serum glucose in group A increased insignificantly after meal. The serum insulin levels were in group A, B and C significant different compared with control group(P<0.05). Those peaked at 1 hour after meal, with group C rising the furthest. Compared with the fasting group, the serum glucagons rose and maintained the increase after breakfast in group A, B and C (P<0.05). The data suggested that various diets with different calorigenic amounts increased hormone concentration to various extents. We found that a breakfast rich in carbohydrates could maintain proper blood glucose level.