DeepHealthNet: Adolescent Obesity Prediction System Based on a Deep Learning Framework.

The global prevalence of childhood and adolescent obesity is a major concern due to its association with chronic diseases and long-term health risks. Artificial intelligence technology has been identified as a potential solution to accurately predict obesity rates and provide personalized feedback to adolescents. This study highlights the importance of early identification and prevention of obesity-related health issues. To develop effective algorithms for the prediction of obesity rates and provide personalized feedback, factors such as height, weight, waist circumference, calorie intake, physical activity levels, and other relevant health information must be taken into account. Therefore, by collecting health datasets from 321 adolescents who participated in Would You Do It! application, we proposed an adolescent obesity prediction system that provides personalized predictions and assists individuals in making informed health decisions. Our proposed deep learning framework, DeepHealthNet, effectively trains the model using data augmentation techniques, even when daily health data are limited, resulting in improved prediction accuracy (acc: 0.8842). Additionally, the study revealed variations in the prediction of the obesity rate between boys (acc: 0.9320) and girls (acc: 0.9163), allowing the identification of disparities and the determination of the optimal time to provide feedback. Statistical analysis revealed that the performance of the proposed deep learning framework was more statistically significant (p 0.001) compared to the other general models. The proposed system has the potential to effectively address childhood and adolescent obesity.

Is the Direct Fixation of Displaced Quadrilateral Plates in Acetabular Fractures Necessary?

Quadrilateral plate fractures represent a heterogeneous group of acetabular fractures. Accurate reduction is required to prevent post-traumatic arthritis. The purpose of this study is to determine the reduction effect of the direct fixation of quadrilateral plates in acetabular fractures, and to evaluate the strength of direct fixation compared to indirect fixation. Between 2005 and 2021, 49 patients underwent surgery for open reduction and internal fixation in acetabular fractures with severely displaced quadrilateral plates. Twenty-nine patients comprised the indirect fixation group, and twenty patients comprised the direct fixation group. In a comparison of primary outcome between two groups, 10 out of 29 indirect-group patients and 1 out of 20 direct-group patients developed post-traumatic osteoarthritis, wherein the difference between the two groups is statistically significant. In the assessment of postoperative Matta's radiological reduction status, 19 out of 20 patients in the direct group had achieved anatomical and congruent reduction. The treatment using a direct reduction and internal fixation improved the reduction quality of articular displacement and offered a better survivorship of the affected hip joint.

miRNA-Based Early Healing Mechanism of Extraction Sockets: miR-190a-5p, a Potential Enhancer of Bone Healing.

Objective: Tooth extraction causes a wound with hard and soft tissue defects in the alveolar ridge. Few studies have reported the function of microRNAs (miRNAs) in the healing of extraction sockets. This study used bioinformatics analysis to reveal the possible relevance and role of miRNAs during the early stages following tooth extraction. Materials and Methods: Socket tissues from beagle dogs (Canis familiaris; two males and two females) were collected 1 and 12 hours after extraction of premolars on both sides of the mandible. miRNA expression was profiled through miRNA sequencing, and hub miRNAs showing characteristic expression patterns were selected and subjected to target enrichment analysis. Alkaline phosphatase (ALP) activity analysis and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) were performed to verify the effect of hub miRNA on osteoblast differentiation and bone regeneration in vivo. Results: Five miRNAs were identified to have consistently high expression levels, with cfa-miR-451 showing the highest expression. Additionally, 20 hub miRNAs were selected as candidates expected to play an important role in the healing process. Pathways, such as the MAPK, axon guidance, TGF-ß, and Wnt signaling, were significantly enriched. Among hub miRNAs, miR-190a-5p increased ALP activity and mRNA expression of osteogenic markers and increased new bone formation in vivo. Conclusions: Our findings suggest that miRNAs may be involved in the earliest stages of socket healing after tooth extraction and can play an important role in moderating the entire socket healing mechanism in the extraction socket.

A study on the relationship between the rate of vertebral body height loss before balloon kyphoplasty and early adjacent vertebral fracture.

BACKGROUND: The number of patients with an osteoporotic vertebral compression fracture, which is often accompanied by lower back pain and restrained activities, is growing. Balloon kyphoplasty involves the inflation of a balloon to restore height and reduce kyphotic deformity before stabilization with polymethylmethacrylate. However, there is a great deal of debate about whether balloon kyphoplasty also increases fracture morbidity by either inducing or facilitating subsequent adjacent vertebral fractures. OBJECTIVE: To evaluate the relationship between the rate of vertebral body height loss before balloon kyphoplasty and the etiology of early adjacent vertebral fracture after augmentation. METHODS: A total of 59 patients with osteoporotic vertebral compression fractures who underwent kyphoplasty were enrolled. This study defined early adjacent segmental fractures as new fractures occurring within three months after surgery. This study included the rate of vertebral body height loss. RESULTS: Early adjacent vertebral fractures were diagnosed in nine (15%) of the 59 patients. The patients were divided into two groups, with and without adjacent vertebral fractures. There was no significant difference in terms of age, body mass index, bone mineral density, local kyphotic angle, Cobb's angle, cement volume, cement leakage, and percent height restored between the groups with fractures and without fractures. There was a statistically significant difference between the two groups in the rate of vertebral body height loss. The rate of vertebral body height loss was significantly higher in the fracture group than in the without fracture group. CONCLUSIONS: A high rate of vertebral body height loss increased the risk of early adjacent vertebral fractures after balloon kyphoplasty.

Impact of Al doping on a hydrothermally synthesized ß-Ga2O3 nanostructure for photocatalysis applications.

Aluminum (Al)-doped beta-phase gallium oxide (ß-Ga2O3) nanostructures with different Al concentrations (0 to 3.2 at%) are synthesized using a hydrothermal method. The single phase of the ß-Ga2O3 is maintained without intermediate phases up to Al 3.2 at% doping. As the Al concentration in the ß-Ga2O3 nanostructures increases, the optical bandgap of the ß-Ga2O3 increases from 4.69 (Al 0%) to 4.8 (Al 3.2%). The physical, chemical, and optical properties of the Al-doped ß-Ga2O3 nanostructures are correlated with photocatalytic activity via the degradation of a methylene blue solution under ultraviolet light (254 nm) irradiation. The photocatalytic activity is enhanced by doping a small amount of substitutional Al atoms (0.6 at%) that presumably create shallow level traps in the band gap. These shallow traps retard the recombination process by separating photogenerated electron-hole pairs. On the other hand, once the Al concentration in the Ga2O3 exceeds 0.6 at%, the crystallographic disorder, oxygen vacancy, and grain boundary-related defects increase as the Al concentration increases. These defect-related energy levels are broadly distributed within the bandgap, which act as carrier recombination centers and thereby degrade the photocatalytic activity. The results of this work provide new opportunities for the synthesis of highly effective ß-Ga2O3-based photocatalysts that can generate hydrogen gas and remove harmful volatile organic compounds.

One-Stage Anatomical Revision Anterior Cruciate Ligament Reconstruction: Results According to Tunnel Overlaps.

PURPOSE: To present clinical results according to tunnel overlap in 1-stage anatomical revision anterior cruciate ligament reconstruction (ACLR). METHODS: All patients who underwent revision ACLR performed by a single surgeon (J.H.A.) from 2012 to 2017 and were followed up for >24 months were retrospectively evaluated. The exclusion criteria were concomitant ligament injury, including medial collateral ligament injury, modified Outerbridge grade ≥3 cartilage lesion, and severe meniscus defects. Tunnel overlap was measured on 3-dimensionally reconstructed computed tomography images. Patients in the nonoverlapped femoral tunnel group (group NO, n = 52) were treated with new tunnel drilling that completely avoided previous tunnels, and those in the overlapped femoral tunnel group (group O, n = 41) were treated with a new tunnel that overlapped with previous tunnels. Clinical outcomes were evaluated using the subjective International Knee Documentation Committee (IKDC) and Lysholm scores. Knee joint stability was measured using the Lachman and pivot shift tests. Patients with femoral tunnel widening of ≥14 mm underwent 2-stage ACLR. RESULTS: The mean follow-up duration of 93 patients was 46.9 months (range, 24-97 months). All preoperative subjective and objective IKDC (P<0.001) and Telos stress test scores (P = .016) were significantly improved at the last follow-up. Forty-one patients had overlapping femoral tunnels, whereas 87 had overlapping tibial tunnels. At the last follow-up, subjective IKDC and Lysholm scores (73.6 ± 15.3 vs 74.9 ± 12.1, P = .799 and 80.0 ± 19.2 vs 81.44 ± 13.5, P = .505, respectively) and objective pivot shift (IKDC grade) in the Lachman test (P = .183 and P = .450, respectively) did not differ significantly between groups NO and O, respectively. CONCLUSIONS: One-stage anatomical revision ACLR significantly improved the clinical results. Most tibial tunnels (94%) and approximately one-half (44%) of the femoral tunnels overlapped. The overlapped femoral tunnel group did not show inferior outcomes or stability. LEVEL OF EVIDENCE: Level III, cohort study.

High Failure Rates of Locking Compression Plate Osteosynthesis with Transverse Fracture around a Well-Fixed Stem Tip for Periprosthetic Femoral Fracture.

This study investigated the incidence of failure after locking compression plate (LCP) osteosynthesis around a well-fixed stem of periprosthetic femoral fractures (PFFs). We retrospectively evaluated outcomes of 63 Vancouver type B1 and C PFFs treated with LCP between May 2001 and February 2018. The mean follow-up duration was 47 months. Only patients with fracture fixation with a locking plate without supplemental allograft struts were included. We identified six periprosthetic fractures of proximal Vancouver B1 fractures with spiral pattern (Group A). Vancouver B1 fractures around the stem tip were grouped into seven transverse fracture patterns (Group B) and 38 other fracture patterns such as comminuted, oblique, or spiral (Group C). Vancouver C fractures comprised 12 periprosthetic fractures with spiral, comminuted, or oblique patterns (Group D). Fracture healing without complications was achieved in all six cases in Group A, 4/7 (57%) in Group B, 35/38 (92%) in Group C, and 11/12 (92%) in Group D, respectively. The failure rates of transverse Vancouver type B1 PFFs around the stem tip were significantly different from those of Vancouver type B1/C PFFs with other patterns. For fracture with transverse pattern around the stem tip, additional fixation is necessary because LCP osteosynthesis has high failure rates.

Comparison of femoral tunnel widening after anterior cruciate ligament reconstruction using cortical button fixation versus transfemoral cross-pin fixation: a systematic review and meta-analysis.

BACKGROUND: The aim was to compare tunnel widening of autogenous hamstring anterior cruciate ligament reconstruction (ACLR) using cortical button versus cross-pin femoral fixation. METHODS: The PubMed, Embase, and Cochrane Central Register of Controlled Trials databases were searched from inception to 11 April 2019. The study included all levels of evidence in studies that reported femoral tunnel widening and compared cortical button and cross-pin femoral fixation for ACLR. RESULTS: Six studies were included, covering a total of 344 knees. Using transtibial techniques for ACLR, the mean absolute amount of femoral tunnel widening was significantly greater with cortical button fixation than with transfemoral cross-pin fixation (-0.30 mm; 95% confidence interval (CI) -0.56,-0.05 mm; p= 0.02). Using the transtibial technique, the mean relative percentage of femoral tunnel widening was significantly greater with cortical button fixation than with transfemoral cross pin fixation (-5.73%; 95% CI -10.32, -1.14% ; p= 0.01). CONCLUSION: The present meta-analysis revealed greater widening of the femoral tunnel when using cortical button fixation for hamstring ACLR via the transtibial technique than when using transfemoral cross-pin fixation.

Effects of pectoralis minor length on strength improvement and pain reduction during scapular reposition test.

[Purpose] This study aimed to compare pain and shoulder elevation strength when scapular reposition test is applied to subclinical individuals with a short or long pectoralis minor. [Participants and Methods] Subclinical participants (n=34) with a positive impingement result on at least one of three tests were assigned to short (n=18) or long (n=16) pectoralis minor groups. Impingement tests were repeated with and without scapular reposition test. Visual analog scale was used to measure pain intensities under both conditions. Isometric shoulder elevation strength was measured by dynamometry. Two-way analyzes of variance and paired t-test were used to evaluate the effects of scapular reposition test in the two groups. [Results] The effects of pectoralis minor length on the frequencies of meaningful strength, pain reduction, and positive scapular reposition test result were evaluated. Repositioning reduced pain in both groups. In the short pectoralis minor group, shoulder elevation strength was significantly improved by scapular reposition test. A meaningful strength improvement and positive scapular reposition test result were reported more frequently in the short pectoralis minor group. [Conclusion] Consideration of pectoralis minor length and scapular reposition test results could aid the identification of factors contributing to scapular dyskinesis and related shoulder injuries, thereby enabling the selection of appropriate interventions.

Restoration of the inferomedial orbital strut using a standardized three-dimensional printing implant.

The inferomedial orbital strut (IOS) is the thin bony junction of the orbital medial wall and floor. Its fracture is common and leads to serious complications, including enophthalmos, globe dystopia and diplopia. However, anatomical restoration of the IOS is challenging owing to reduced structural support; sound anatomical background and accurate implants are therefore essential. The aim of the present study was to incorporate data from cadaveric orbit anatomy into three-dimensional (3D) printing technology and to reconstruct the complex orbital fracture elaborately. After averaging the data from computed tomography (CT) images of 100 adult cadavers, the dimensions of the IOS were extracted, and a tangent sphere was created using a computer-aided design program. The curves were compared with the CT data of 10 adult patients from the simulation test. Based on these data, a standardized 3D implant, 1.15 mm thick, was designed using polycaprolactone. The implant was placed in five patients with complex orbital fractures. The radius of the sphere in contact with the orbit, measuring 33.54 mm, was confirmed to be appropriate. A comparison between the normal side volume (V0) and the postoperative volume (Vpost ) showed that they were statistically similar. Furthermore, a comparison between V0 and the preoperative volume (Vpre ), and Vpost compared with Vpre also showed a statistically significant difference (P < 0.05). On follow-up, the preoperative ocular symptoms were resolved. The orbital data obtained from 100 cadavers provided standardized orbital anatomy, and 3D printed implants were created. The implants were anatomically accurate with regard to the orbital cavity and adequately covered the simulation model. The implant also showed satisfactory results when applied clinically in actual patients.

Microbial Synthesis of Linoleate 9 S-Lipoxygenase Derived Plant C18 Oxylipins from C18 Polyunsaturated Fatty Acids.

Plant oxylipins, including hydroxy fatty acids, epoxy hydroxy fatty acids, and trihydroxy fatty acids, which are biosynthesized from C18 polyunsaturated fatty acids (PUFAs), are involved in pathogen-specific defense mechanisms against fungal infections. However, their quantitative biotransformation by plant enzymes has not been reported. A few bacteria produce C18 trihydroxy fatty acids, but the enzymes and pathways related to the biosynthesis of plant oxylipins in bacteria have not been reported. In this study, we first report the biotransformation of C18 PUFAs into plant C18 oxylipins by expressing linoleate 9 S-lipoxygenase with and without epoxide hydrolase from the proteobacterium Myxococcus xanthus in recombinant Escherichia coli. Among the nine types of plant oxylipins, 12,13-epoxy-14-hydroxy- cis, cis-9,15-octadecadienoic acid was identified as a new compound by NMR analysis, and 9,10,11-hydroxy- cis, cis-6,12-octadecadienoic acid and 12,13,14-trihydroxy- cis, cis-9,15-octadecadienoic were suggested as new compounds by LC-MS/MS analysis. This study shows that bioactive plant oxylipins can be produced by microbial enzymes.

High-Aspect Ratio ß-Ga2O3 Nanorods via Hydrothermal Synthesis.

High-aspect ratio ß-Ga2O3 nanorods consisting of prism-like crystals were formed using gallium oxyhydroxide and ammonia hydroxide via a hydrothermal synthesis followed by the subsequent calcination process. The formation of high-aspect ratio ß-Ga2O3 nanorods was attributed to the oriented attachment mechanism that was present during the hydrothermal synthesis. A field-effect transistor was fabricated using the high-aspect ratio ß-Ga2O3 nanorod, and it exhibited the typical charge transfer properties of an n-type semiconductor. This facile approach to forming high-aspect ratio nanorods without any surfactants or additives can broaden the science of ß-Ga2O3 and expedite the integration of one-dimensional ß-Ga2O3 into future electronics, sensors, and optoelectronics.

Efficacy of Pectoral Nerve Block Type II for Breast-Conserving Surgery and Sentinel Lymph Node Biopsy: A Prospective Randomized Controlled Study.

Objectives: The pectoral nerve block type II (PECS II block) is widely used for postoperative analgesia after breast surgery. This study evaluated the analgesic efficacy of PECS II block in patients undergoing breast-conserving surgery (BCS) and sentinel lymph node biopsy (SNB). Methods: Patients were randomized to the control group (n=40) and the PECS II group (n=40). An ultrasound-guided PECS II block was performed after induction of anesthesia. The primary outcome measure was opioid consumption, and the secondary outcome was pain at the breast and axillary measured using the Numerical Rating Scale (NRS) 24 hours after surgery. Opioid requirement was assessed according to tumor location. Results: Opioid requirement was lower in the PECS II than in the control group (43.8 ± 28.5 µg versus 77.0 ± 41.9 µg, p < 0.001). However, the frequency of rescue analgesics did not differ between these groups. Opioid consumption in the PECS II group was significantly lower in patients with tumors in the outer area than that in patients with tumors in the inner area (32.5 ± 23.0 µg versus 58.0 ± 29.3 µg, p=0.007). The axillary NRS was consistently lower through 24 hr in the PECS II group. Conclusion: Although the PECS II block seemed to reduce pain intensity and opioid requirements for 24 h after BCS and SNB, these reductions may not be clinically significant. This trial is registered with Clinical Research Information Service KCT0002509.

Synergistic Effects of Beta Tri-Calcium Phosphate and Porcine-Derived Decellularized Bone Extracellular Matrix in 3D-Printed Polycaprolactone Scaffold on Bone Regeneration.

Bone-derived extracellular matrix (ECM) is widely used in studies on bone regeneration because of its ability to provide a microenvironment of native bone tissue. However, a hydrogel, which is a main type of ECM application, is limited to use for bone graft substitutes due to relative lack of mechanical properties. The present study aims to fabricate a scaffold for guiding effective bone regeneration. A polycaprolactone (PCL)/beta-tricalcium phosphate (ß-TCP)/bone decellularized extracellular matrix (dECM) scaffold capable of providing physical and physiological environment are fabricated using 3D printing technology and decoration method. PCL/ß-TCP/bone dECM scaffolds exhibit excellent cell seeding efficiency, proliferation, and early and late osteogenic differentiation capacity in vitro. In addition, outstanding results of bone regeneration are observed in PCL/ß-TCP/bone dECM scaffold group in the rabbit calvarial defect model in vivo. These results indicate that PCL/ß-TCP/bone dECM scaffolds have an outstanding potential as bone graft substitutes for effective bone regeneration.

Preparation of Wrinkled Graphene Oxide Using Solution Method.

Wrinkled graphene oxide (WGO) is formed using the solution method. The sub-µm-sized wrinkles are generated on the GO surface, with more wrinkles forming as the GaCl3 in the solution increases. The wrinkles are observed using scanning electron microscopy (SEM) and atomic force microscopy (AFM) methods. The OH bonds connected to the GO surface are believed to cause the WGO, and these additional chemical bonds are detected via the Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy. As with the wrinkled graphene, the wrinkled GO provides a much larger surface area and can expedite the production of advanced sensor and energy charging devices.

Ultrasound-Guided Genicular Nerve Block for Knee Osteoarthritis: A Double-Blind, Randomized Controlled Trial of Local Anesthetic Alone or in Combination with Corticosteroid.

BACKGROUND: Recently, several studies suggested that radiofrequency (RF) ablation of the genicular nerves is a safe and effective therapeutic procedure for intractable pain associated with chronic knee osteoarthritis (OA). Diagnostic genicular nerve block (GNB) with local anesthetic has been generally conducted before making decisions regarding RF ablation. Although GNB has been recently performed together with corticosteroid, the analgesic effects of corticosteroids for treating chronic pain remain controversial. OBJECTIVES: The current study aims to assess the effects of combining corticosteroids and local anesthesia during ultrasound-guided GNB in patients with chronic knee OA. STUDY DESIGN: A randomized, double-blinded institutional study. SETTING: This study took place at Asan Medical Center in Seoul, Korea. METHODS: Forty-eight patients with chronic knee OA were randomly assigned to either the lidocaine alone group (n = 24) or lidocaine plus triamcinolone (TA) group (n = 24) before ultrasound-guided GNB. Visual analog scale (VAS), Oxford Knee Score (OKS), and global perceived effects (7-point scale) were assessed at baseline and at 1, 2, 4, and 8 weeks after the procedure. RESULTS: The VAS scores were significantly lower in the lidocaine plus TA group than in the lidocaine alone group at both 2 (P < 0.001) and 4 (P < 0.001) weeks after GNB. The alleviation of intense pain in the lidocaine plus TA group was sustained up to 2 weeks after the procedure, in accordance with the definition of a minimal clinically important improvement. Although a similar intergroup difference in OKSs was observed at 4 weeks (P < 0.001), the clinical improvement in functional capacity lasted for only one week after the reassessment of OKSs, in accordance with a minimal important change. No patient reported any postprocedural adverse events during the follow-up period. LIMITATIONS: The emotional state of the patients, which might affect the perception of knee pain, was not evaluated. The follow-up period was 2 months; this period might be insufficient to validate the short-term effects of GNB. CONCLUSIONS: Ultrasound-guided GNB, when combined with a local anesthetic and corticosteroid, can provide short-term pain relief. However, the clinical benefit of corticosteroid administration was not clear in comparison with local anesthesia alone. Given the potential adverse effects, corticosteroids might not be appropriate as adjuvants during a GNB for chronic knee OA.The study protocol was approved by our institutional review board (2012-0210), and written informed consent was obtained from all patients. The trial was registered with the Clinical Research Information Service (KCT 0001139). KEY WORDS: Chronic pain, knee osteoarthritis, genicular nerve block, ultrasound, corticosteroid, local anesthetic, visual analog scale, Oxford Knee Score.

Impedance Spectroscopy Analysis and Equivalent Circuit Modeling of Graphene Oxide Solutions.

The optical and electrical characteristics of a graphene oxide solution (GS) with different graphene oxide (GO) concentrations in de-ionized water are investigated via the electrochemical impedance spectroscopy (EIS) method. The measurement results produced by the EIS for the GS are represented with both Bode and Nyquist plots in a frequency range from 1 kHz to 10 MHz. Using these results, we develop an equivalent circuit model as a function of the GO concentration, representing the GS as a mixed circuit of two-dimensional (2D) GO dispersed in parallel in de-ionized (DI) water. The underlying physics of the current-flowing behavior in the GS are explained and interpreted using empirical circuit models; the circuit model also shows that highly resistive GO becomes conductive in GS form in the DI water. The findings in this work should draw new attention toward GSes and related applications, including functional composite materials, catalysts, and filter membranes.

Compliment Graphene Oxide Coating on Silk Fiber Surface via Electrostatic Force for Capacitive Humidity Sensor Applications.

Cylindrical silk fiber (SF) was coated with Graphene oxide (GO) for capacitive humidity sensor applications. Negatively charged GO in the solution was attracted to the positively charged SF surface via electrostatic force without any help from adhesive intermediates. The magnitude of the positively charged SF surface was controlled through the static electricity charges created on the SF surface. The GO coating ability on the SF improved as the SF's positive charge increased. The GO-coated SFs at various conditions were characterized using an optical microscope, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), Raman spectroscopy, and LCR meter. Unlike the intact SF, the GO-coated SF showed clear response-recovery behavior and well-behaved repeatability when it was exposed to 20% relative humidity (RH) and 90% RH alternatively in a capacitive mode. This approach allows humidity sensors to take advantage of GO's excellent sensing properties and SF's flexibility, expediting the production of flexible, low power consumption devices at relatively low costs.

A Gallium Oxide-Graphene Oxide Hybrid Composite for Enhanced Photocatalytic Reaction.

Hybrid composites (HCs) made up of gallium oxide (GaO) and graphene oxide (GO) were investigated with the intent of enhancing a photocatalytic reaction under ultraviolet (UV) radiation. The material properties of both GaO and GO were preserved, even after the formation of the HCs. The incorporation of the GO into the GaO significantly enhanced the photocatalytic reaction, as indicated by the amount of methylene blue (MB) degradation. The improvements in the reaction were discussed in terms of increased surface area and the retarded recombination of generated charged carriers.

Intraoperative infusion of 0.6-0.9 µg·kg(-1)·min(-1) remifentanil induces acute tolerance in young children after laparoscopic ureteroneocystostomy.

BACKGROUND: Intraoperative infusion of opioids has been associated with increased postoperative pain and analgesic requirements, but the development of tolerance in young children is less clear. This prospective, randomized, double-blinded study was designed to test the hypothesis that the intraoperative administration of remifentanil results in postoperative opioid tolerance in a dose-related manner in young children. METHODS: We enrolled 60 children (aged 1-5 yr) who were undergoing elective laparoscopic ureteroneocystostomy. Patients were randomized and received an intraoperative infusion of 0, 0.3, 0.6, or 0.9 µg·kg·min remifentanil. Postoperative pain was managed by a parent/nurse-controlled analgesia pump using fentanyl. The primary outcome included the total fentanyl consumptions at 24 and 48 h postsurgery. Secondary outcomes were the postoperative pain scores and adverse effects. RESULTS: The children who received 0.6 and 0.9 µg·kg·min remifentanil required more postoperative fentanyl than the children who received saline or 0.3 µg·kg·min remifentanil (all P < 0.001) for 24 h after surgery. The children who received 0.3-0.9 µg·kg·min intraoperative remifentanil reported higher pain scores at 1 h after surgery than the children who received saline (P = 0.002, P = 0.023, and P = 0.006, respectively). No significant intergroup differences in recovery variables were observed, but vomiting was more frequent in the 0.9 µg·kg·min remifentanil group than in the other groups (P = 0.027). CONCLUSIONS: The intraoperative use of 0.3 µg·kg·min remifentanil for approximately 3 h (range: 140-265 min) did not induce acute tolerance, but the administration of 0.6 and 0.9 µg·kg·min remifentanil to young children resulted in acute tolerance for 24 h after surgery in an apparently dose-related manner.