Postoperative Pain Management Outcomes at a Chinese Hospital: A Cross-Sectional Survey.

PURPOSE: Postoperative pain is one of the most common postoperative complications, and improper management not only adds to patient suffering but also affects patients' recovery. In this study, we measured patients' postoperative pain to understand the status of patients after surgery and to identify factors influencing postoperative pain. DESIGN: A descriptive and cross-sectional study METHODS: This survey was conducted at a large tertiary hospital in Chengdu, Sichuan Province. A total of 655 postoperative inpatients were included. The survey was conducted using the Chinese version of the Houston Pain Outcome Instrument. General patient data, pain management-related factors, and the pain management index were used to survey risk factors. We used t-tests and ANOVA for univariate analysis of each pain outcome category to explore the association with the predictor variables. Then, those variables with a significance level of 0.05 on univariate analysis were entered into multivariable regression analysis to identify parsimonious subsets of independent risk factors. FINDINGS: In this survey, 58.7% of patients experienced moderate to severe pain in the 24-hour postoperative period, and 33.6% of patients had moderate to severe average pain over the 24-hour postoperative period. The postoperative pain impact scores on patient mood, somatic function, patient satisfaction with postoperative pain management, and pain education were 3.5 ± 2.1, 4.3 ± 3.1, 8.9 ± 1.4 and 8.2 ± 1.8, respectively. The pain management index, surgery type, insurance, and pain assessment of nurse were influential factors of postoperative pain intensity. Age, ethnicity, insurance, surgery type, patents' knowledge of pain, and pain assessment of the nurse affected the patients' postoperative physiological function (F = 3.822, R2 = 0.065, P = .000). In addition, area of residence and physician attitudes affected the outcomes of patient satisfaction with pain management (F = 26.652, R2 = 0.259, P = .000). CONCLUSIONS: The incidence of moderate to severe pain in post-surgical patients remains high, and postoperative pain affects patients physically and psychologically. Special attention should be given to patients with lower income and literacy levels.

[Correlation Between 6 Characteristics of Perioperative Hypothermia and Allogeneic Red Blood Cell Transfusion in Abdominal Surgery Patients]. / è ¹éƒ¨æ‰‹æœ¯æ‚£è€ å›´æœ¯æœŸå ­ç§ä½Žä½“æ¸©ç‰¹å¾ä¸Žå¼‚ä½“çº¢ç»†èƒžè¾“æ³¨çš„å ³è”æ€§åˆ†æž.

Objective: To explore the correlation between six characteristics of perioperative hypothermia and allogeneic red blood cell (RBC) transfusions in patients who underwent abdominal surgeries. Methods: Patients who underwent abdominal surgeries at West China Hospital, Sichuan University between October 2019 and July 2021 were retrospectively enrolled. A wearable wireless temperature sensor was used to continuously monitor the core body temperature of patients throughout the perioperative period. The perioperative temperature nadir, maximum temperature loss, percentage of time with hypothermia, time-weighted average temperature, area under the curve (AUC) at 36 ℃, and AUC at 37 ℃ were calculated for the period from entering the operation room to 24 hours after the end of anesthesia. The restricted cubic spline (RCS) and multiple logistic regression models were used to explore the correlation between these temperature characteristics and perioperative allogeneic RBC transfusions. Results: A total of 3119 patients were included in the study, with an allogeneic RBC transfusion rate of 2.8%. The RCS model showed that allogeneic RBC transfusion was associated with the perioperative temperature nadir (Poverall=0.048) and AUC at 36 ℃ (Poverall=0.026) and no statistical significance was found in the nonlinear test. The association between allogeneic RBC transfusions and other temperature characteristics was not statistically significant. According to the RCS model results, cut-off points were taken to form groups based on the body temperature characteristics. Multivariate logistic regression showed that the perioperative temperature nadir<35.5 ℃ (odds ratio [OR]=2.47, 95% confidence interval [CI]: 1.21-5.03) and AUC at 36 ℃≥100 ℃·min (OR=2.24, 95% CI:1.09-4.58) were associated with increased demand for allogeneic RBC transfusion. Conclusion: Hypothermia is associated with an increased need for perioperative allogeneic RBC transfusions and has a cumulative effect over time. For patients at high risk of bleeding, attention should be paid to the prevention of perioperative hypothermia and reduction in the cumulative exposure to hypothermia, thereby reducing the need for blood transfusion.

Trends in the prevalence of metabolically healthy and unhealthy obesity in the US adult population: analysis of eight NHANES cross-sectional survey cycles, 1999-2014.

OBJECTIVE: To exam the time trend of the prevalence of metabolically healthy obesity (MHO) in the US adult population. DESIGN: Eight cross-sectional survey cycles. SETTING: National Health and Nutrition Examination Survey (NHANES), 1999-2014. PARTICIPANTS: 16 459 NHANES participants aged 20 years and older. PRIMARY OUTCOME MEASURE: MHO was defined as central obesity (waist circumference ≥102 cm for men and ≥88 cm for women) without any of the following conditions: elevated levels of blood pressure (≥130/85 mm Hg), glucose (≥100 mg/dL) and triglycerides (≥150 mm/dL); reduced levels of high-density lipoprotein cholesterol (<40 mg/dL for men and <50 mg/dL for women) or any medication use for high cholesterol, hypertension or diabetes. RESULTS: The prevalence of central obesity significantly increased from 45.2% in 1999-2000 to 56.7% in 2013-2014 (p=0.003). Over the same period, MHO prevalence among those with central obesity only slightly and non-significantly increased from 11.0% to 15.7% (p=0.38). However, MHO prevalence among women increased significantly (p=0.04) from 7.1% to 13.7%. Female gender, a younger age, being Hispanic and non-Hispanic black and high education (some college or above) were significantly (p<0.05) associated with higher prevalence of MHO. CONCLUSIONS: While the prevalence of central obesity in the US population has increased since 1999, the prevalence of MHO among those who are centrally obese remained fairly stable.

Investigation of the Quality of Recovery of Surgical Patients Based on the Chinese Version of the Quality of Recovery-15 Survey, a Cross-Sectional Study.

PURPOSE: The quality of recovery (QoR) is an important indicator of a patient's health status in the early postoperative period. Despite its importance, the QoR from the patient's perspective is often neglected in clinical practice. This study was performed to survey and determine the QoR of surgical patients from their own subjective perspective and to provide a reference for the targeted postoperative care of surgical patients in the future. DESIGN: A descriptive and cross-sectional study. METHODS: The Chinese version of the Quality of Recovery-15 (QoR-15) scale was used to survey the QoR of 503 surgical patients in 20 surgical wards from 17 surgical departments of a large tertiary hospital in Sichuan Province, China. A questionnaire survey was administered to each patient before and after the operation, and the scores were compared. FINDINGS: There were no significant differences in "feeling worried or anxious" and "feeling sad or depressed" between the preoperative and postoperative periods (P > 0.05). The postoperative scores for the other items were significantly lower than the preoperative scores. The total postoperative QoR-15 score was significantly lower than the total preoperative score (P < 0.001). CONCLUSIONS: The QoR-15 scores of surgical patients were lower after the surgery than before, and patients still needed care after discharge. Therefore, due to the gradual shortening of the length of stay (LOS) of surgical patients, it is necessary for hospitals to construct a complete surgical patient transitional care process to meet the needs of patients after discharge and promote patient rehabilitation.

Risk of falls in 4 years of follow-up among Chinese adults with diabetes: findings from the China Health and Retirement Longitudinal Study.

OBJECTIVES: This study was to determine the incidence of falls and identify baseline factors increased risk for incident falls over time among people with diabetes. DESIGN: This study was a secondary analysis using the baseline and 4 years of follow-up data from the China Health and Retirement Longitudinal Study (CHARLS). SETTING: A nationally representative survey of 17 500 Chinese residents aged 45 years and older were recruited in the baseline national survey in 2011. These participants were followed up every 2 years. PARTICIPANTS: A total of 1238 middle-aged and older adults with diabetes and no history of falls at baseline were included in the current study. PRIMARY AND SECONDARY OUTCOME MEASURES: Information on incidence of falls and medical treatment resulting from falls were determined by self-report. RESULTS: The findings showed that the incidence of falls was 29.4% during 4 years of follow-up. Participants with incident falls were younger, were more likely to be women, had lower education level and were less likely to be current drinkers. In addition, former drinkers were 2.22 times more likely to fall. Socially active individuals were 47% less likely to fall compared with those without social activities. Every 5 kg increase in grip strength was associated with a 13% lower risk of falls. A 10 mg/dL higher total cholesterol and 1 mg/dL higher blood urea nitrogen were associated with a 4% and 6% higher risk of falls. Finally, participants with depressive symptoms were 1.47 times more likely to fall compared with those without depressive symptoms. CONCLUSIONS: These findings underscore the importance of developing a fall prevention programme for those with diabetes, and this programme should address potentially modifiable risk factors, including levels of total cholesterol, blood urea nitrogen, social activity, depressive symptoms and grip strength.

Key Experimental Factors of Machine Learning-Based Identification of Surgery Cancellations.

This study aimed to provide effective methods for the identification of surgeries with high cancellation risk based on machine learning models and analyze the key factors that affect the identification performance. The data covered the period from January 1, 2013, to December 31, 2014, at West China Hospital in China, which focus on elective urologic surgeries. All surgeries were scheduled one day in advance, and all cancellations were of institutional resource- and capacity-related types. Feature selection strategies, machine learning models, and sampling methods are the most discussed topic in general machine learning researches and have a direct impact on the performance of machine learning models. Hence, they were considered to systematically generate complete schemes in machine learning-based identification of surgery cancellations. The results proved the feasibility and robustness of identifying surgeries with high cancellation risk, with the considerable maximum of area under the curve (AUC) (0.7199) for random forest model with original sampling using backward selection strategy. In addition, one-side Delong test and sum of square error analysis were conducted to measure the effects of feature selection strategy, machine learning model, and sampling method on the identification of surgeries with high cancellation risk, and the selection of machine learning model was identified as the key factors that affect the identification of surgeries with high cancellation risk. This study offers methodology and insights for identifying the key experimental factors for identifying surgery cancellations, and it is helpful to further research on machine learning-based identification of surgeries with high cancellation risk.

Evaluation of a wearable wireless device with artificial intelligence, iThermonitor WT705, for continuous temperature monitoring for patients in surgical wards: a prospective comparative study.

OBJECTIVES: To evaluate a new-generation, non-invasive, wireless axillary thermometer with artificial intelligence, iThermonitor (WT705, Raiing Medical, Beijing, China), and to ascertain its feasibility for perioperative continuous body temperature monitoring in surgical patients. SETTING: Departments of Biliary Surgery and Operating Room and the post-anaesthesia care unit of a university teaching hospital in Chengdu, China. PARTICIPANTS: A total of 526 adult surgical patients were consecutively enrolled. DESIGN: This was a prospective observational study. Axillary temperatures were continuously recorded with iThermonitor throughout the whole perioperative period. The temperatures of the contralateral armpit were measured with mercury thermometers at 8:00, 12:00, 16:00 and 20:00 every day and were used as references. OUTCOME MEASURES: The outcomes were the accuracy and precision of the temperatures measured with iThermonitor, the validity to detect fever and the feasibility of continuous wear. Pairs of temperatures were evaluated with Student's t-test, Pearson's correlation and repeated-measures Bland-Altman plot. RESULTS: A total of 3621 pairs of body temperatures were obtained. The temperatures measured with iThermonitor agreed with those measured with the mercury thermometers overall, with a mean difference of 0.03°C±0.35°C and a moderate correlation (r=0.755, p<0.001). The 95% limits of agreement (LoA) ranged from -0.63°C to 0.73°C, with 5.11% of the differences outside the 95% LoA. The intraclass correlation coefficient was 0.753. Continuous temperature monitoring captured more fevers than intermittent observation (117/526 vs 91/526, p<0.001), detected fever up to 4.35 hours earlier, and captured a higher peak temperature (0.29°C±0.27°C, 95% CI: 0.26-0.31). All subjects felt that wearing iThermonitor was more or less comfortable and did not affect their daily activities. CONCLUSIONS: iThermonitor is promising for continuous remote temperature monitoring in surgical patients. However, further developments are still needed to improve the precision of this device, especially for temperature detection in underweight patients and those with lower body temperature. TRIAL REGISTRATION NUMBER: ChiCTR1900024549; Results (registered on 5 July 2019).

Machine learning for identification of surgeries with high risks of cancellation.

Surgery cancellations waste scarce operative resources and hinder patients' access to operative services. In this study, the Wilcoxon and chi-square tests were used for predictor selection, and three machine learning models - random forest, support vector machine, and XGBoost - were used for the identification of surgeries with high risks of cancellation. The optimal performances of the identification models were as follows: sensitivity - 0.615; specificity - 0.957; positive predictive value - 0.454; negative predictive value - 0.904; accuracy - 0.647; and area under the receiver operating characteristic curve - 0.682. Of the three models, the random forest model achieved the best performance. Thus, the effective identification of surgeries with high risks of cancellation is feasible with stable performance. Models and sampling methods significantly affect the performance of identification. This study is a new application of machine learning for the identification of surgeries with high risks of cancellation and facilitation of surgery resource management.

The placental growth factor attenuates intimal hyperplasia in vein grafts by improving endothelial dysfunction.

Saphenous vein grafts (SVG) patency is limited by intimal hyperplasia (IH) caused by endothelial dysfunction. This study aimed to explore the effect of placental growth factor (PlGF) on the endothelial function of SVG. In rat models of external jugular vein-carotid artery graft treated with PlGF or saline hydrogel, PlGF inhibited vein graft IH (day 28: 12.0 ± 1.9 vs. 61.7 ± 13.1 µm, P < 0.001), promoted microvessel proliferation (day 14: 33.3% 3+ vs. 50.0% 2+, P = 0.03), and increased nitric oxide (NO) production (P < 0.05 on days 1/3/5) and NO synthase (NOS) expression by immunohistochemistry. In human umbilical vein endothelial cells (HUVECs) cultured under hypoxia and treated or not with PlGF, PlGF restored the survival (50 ng/ml PlGF, 48 h: 91.7 ± 0.6% vs. 84.9 ± 0.5%, P < 0.01), migration (by Matrigel assay), and tube formation ability (junctions, tubules, and tubule total length; all P < 0.01) of HUVECs after hypoxia. PlGF increased NO production through increased eNOS expression (P < 0.05), without changes in iNOS expression. The mRNA expression of eNOS decreased after the addition of the PI3K inhibitor LY294002 (P < 0.05). PlGF promoted the protein expression of eNOS by up-regulating AKT, and the AKT and eNOS protein levels were decreased after adding LY294002 (all P < 0.05). In conclusion, PlGF is a candidate for the inhibition of IH in SVG after coronary artery bypass graft. The effects of PlGF are mediated by the upregulation of the eNOS mRNA and protein through the PI3K/AKT signaling pathway. PlGF promotes the secretion of NO by endothelial cells and thereby reduces the occurrence and development of IH.

A random forest and simulation approach for scheduling operation rooms: Elective surgery cancelation in a Chinese hospital urology department.

Many hospitals encounter surgery cancelations for various reasons. We present a methodology applying data mining and simulation to optimize operating room (OR) scheduling in a urology department in West China Hospital. To the best of our knowledge, this is 1 of the first efforts to seek an optimal schedule solution based on cancelation risk of elective surgeries as well as OR allocation between elective and nonelective surgeries. First, chi-square test and random forest prediction modeling were used to predict potential elective surgeries with high cancelation risk, and the factors, including surgeon, number of days since admission of patient, first surgery or not, etc., that influence elective surgery cancelation were identified. Second, a simulation technology was designed to compare 7 different scheduling strategies. The results demonstrated that for elective surgery, cancelation rate low surgery first outperformed the others and increased the productivity of the ORs from 72% to 83%, while for nonelective surgery performed in a separate OR, there was no improvement because the supply was greater than necessary at present. However, in total, the selected strategies led to 7% higher productivity.

Contributing factors of elective surgical case cancellation: a retrospective cross-sectional study at a single-site hospital.

BACKGROUND: Case cancellation (CC) has significant impact on the efficiency of operating room (OR) management, which can be mitigated by taking preventive measures. In this study, using the data of the West China Hospital (WCH), we identified the effect of contributing factors and recommended hospital interventions to facilitate CC prevention. METHOD: We conducted a retrospective review of 11,331 elective surgical cases from January 1 to December 31, 2014. CC reasons were grouped into six categories. The methods of descriptive statistics and hypothesis test were used to identify the effect of factors. RESULTS: CC reasons (746) were divided into six broad categories: workup related (preoperative diagnostic assessment issues or sudden medical condition changes) (25.8%), non-specified reasons (25.8%), coordination issues (15.1%), patient related (13.0%), support system issues (11.8%), and doctor related (8.5%). The types of the most frequently performed operations are identified, as well as their CRs. The cancellation rate (CR) of males was lower than that of females (16.7% to 18.3%). A large difference in the CRs existed among doctors. The CR on Monday was significantly higher than the other four weekdays. CONCLUSIONS: Workup related issues, the types of procedures, the menstrual cycle of females, highly imbalanced CRs among doctors, and tendency of cancellation on Monday are the major identified factors, which account for a significant amount of preventable cancellations. It is suggested that corresponding hospital interventions can reduce CR and improve OR efficiency, including maintaining effective coordination, good communication and well-designed preoperative assessment processes, focusing on the type of procedures which are more time-consuming and complex, paying special attention to the physiology of females during surgery planning, taking measures to reduce CR of top eight doctors, and improving surgery scheduling on Monday.

A MIP Model for Rolling Horizon Surgery Scheduling.

Most surgery scheduling is done 1 day in advance. Caused by lack of overall planning, this scheduling scheme often results in unbalanced occupancy time of the operating rooms. So we put forward a rolling horizon mixed integer programming model for the scheduling. Rolling horizon scheduling refers to a scheduling scheme in which cyclic surgical requests are taken into account. Surgical requests are updated daily. The completed surgeries are eliminated, and new surgeries are added to the scheduling list. Considering day-to-day demand for surgery, we develop a non-rolling scheduling model (NRSM) and a rolling horizon scheduling model (RSM). By comparing the two, we find that the quality of surgery scheduling is significantly influenced by the variation in demand from day to day. A rolling horizon scheduling will enable a more flexible planning of the pool of surgeries that have not been scheduled into this main blocks, and hence minimize the idle time of operating rooms. The strategy of the RSM helps balance the occupancy time among operating rooms. Using surgical data from five departments of the West China Hospital (WCH), we generate surgical demands randomly to compare the NRSM and the RSM. The results show the operating rooms' average utilization rate using RSM is significantly higher than when applying NRSM.

Identification of genes associated with methotrexate resistance in methotrexate-resistant osteosarcoma cell lines.

BACKGROUND: This study aimed to better understand the mechanisms underlying methotrexate (MTX)-resistance in osteosarcoma. METHODS: The raw transcription microarray data GSE16089 collected from three MTX-sensitive osteosarcoma (Saos-2) cell samples and three MTX-resistant osteosarcoma (Saos-2) cell samples were downloaded from Gene Expression Omnibus. After data processing, the differentially expressed genes (DEGs) were identified. Next, DEGs were submitted to DAVID for functional annotation based on the GO (Gene Ontology) database, as well as pathway enrichment analysis based on the KEGG (Kyoto Encyclopedia of Genes and Genomes) database. Transcription factors (TFs) and tumor-associated genes (TAGs) were identified with reference to TRANSFAC and TAG, and TSGene databases, respectively. The protein-protein interaction (PPI) network of the gene-encoded products was constructed, and the subnetwork with the highest score was also detected using Search Tool for the Retrieval of Interacting Genes and BioNet package. RESULTS: A total of 690 up-regulated genes and down-regulated 626 genes were identified. Up-regulated DEGs (including AARS and PARS2) were associated to transfer RNA (tRNA) aminoacylation while down-regulated DEGs (including AURKA, CCNB1, CCNE2, CDK1, and CENPA) were correlated with mitotic cell cycle. Totally, 13 TFs (including HMGB2), 13 oncogenes (including CCNA2 and AURKA), and 19 tumor suppressor genes (TSGs) (including CDKN2C) were identified from the down-regulated DEGs. Ten DEGs, including nine down-regulated genes (such as AURKA, CDK1, CCNE2, and CENPA) and one up-regulated gene (GADD45A), were involved in the highest score subnetwork. CONCLUSION: AARS, AURKA, AURKB, CENPA, CCNB1, CCNE2, and CDK may contribute to MTX resistance via aminoacyl-tRNA biosynthesis pathway, cell cycle pathway, or p53 signaling pathway.

[Effects of APOC3 polymorphisms on the plasma lipids in healthy adolescents with different body mass index].

OBJECTIVE: To investigate the possible effects of apolipoprotein C I gene (APOC3) polymorphisms on plasma lipids in healthy adolescents with different body mass index (BMI). METHODS: Seven hundred and twenty three adolescents were divided into four groups according to BMI: group 1 CBMI= (17.80 +/- 0.75) kg/m2,n=180], group 2 [BMI = (19.39 +/- 0.32) kg/m2, n=182), group 3 [BMI= (20.68 +/- 0.43) kg/m2, n=1813 and group 4 [BMI= (23.40 +/- 2.05) kg/m2 ,n=180J. Fasting venous blood samples were collected, plasma lipids were determined and genome DNA was extracted for determining the genotypes of the APOC3 Sst I and -482C>T polymorphisms by PCR-RFLP. RESULTS: With the elevation of BMI, height and plasma high-density lipoprotein cholesterol decreased significantly (P<0.001 for both), body mass, waist circumference, hip circumference, waist/hip ratio, plasma triglycerides (TG), total cholesterol and low-density lipoprotein cholesterol levels increased significantly (P<0.001 for all). No significant differences in TG levels among Sst I genotypes were observed in group 1, group 2 and group 3; but in group 4, significant differences in TG levels among Sst I genotypes were observed, S2 carriers had higher TG levels than the adolescents with S1S1 genotype. No significant differences in plasma lipids among -482C>T genotypes were observed in all groups. CONCLUSION: The elevation of plasma TG levels by the S2 allele of APOC3 Sst I polymorphism is associated with BMI. It is possible that the reduction of body mass could favorably modulate the elevation of TG levels by S2 allele in healthy adolescents.

[Effects of apolipoprotein A1 gene rs670 and rs5069 polymorphisms on the plasma lipid profiles in healthy adolescents with different body mass index].

OBJECTIVE: To investigate the possible effects of apolipoprotein A1 gene (APOA1) rs670 and rs5069 polymorphisms on plasma lipid profiles in healthy adolescents with different body mass index (BMI). METHODS: Totally 723 adolescents were divided into four groups according to their BMI: group 1[BMI =(17.80 ± 0.75)kg/m2], group 2[BMI = (19.39 ± 0.32) kg/m²], group 3[BMI = (20.68 ± 0.43) kg/m²], and group 4[BMI=(23.40 ± 2.05) kg/m²]. Height, weight, waist circumference, hip circumference, blood pressure, heart rate, plasma lipids, and blood glucose were determined, BMI and waist to hip ratio (W/H ratio) were calculated,and genome DNA was extracted for analyzing the genotypes of the APOA1 rs670 and rs5069 polymorphisms by polymerase chain reaction-restriction fragment length polymorphism. RESULTS: No significant differences in height, weight, BMI, waist circumference, hip circumference, W/H ratio, blood pressure, heart rate, plasma lipids, and blood glucose between APOA1 rs670 or rs5069 genotypes were observed among group 1, group 2, and group 3. In group 4, A carriers of the rs670 polymorphism had significantly higher systolic blood pressure (P=0.017) and blood glucose levels (P=0.009) than the adolescents with the GG genotype. T carriers of the rs5069 polymorphism had significantly higher height (P=0.013), weight (P=0.011), and hip circumference (P=0.026) than the adolescents with the CC genotype. CONCLUSIONS: In healthy adolescents with higher BMI, APOA1 rs670 polymorphism is associated with systolic blood pressure and blood glucose levels. The elevation of systolic blood pressure and blood glucose levels in A carriers of APOA1 rs670 polymorphism may be favorably modulated by weight loss.

Sequence-dependent anesthesia-controlled times: a retrospective study in an ophthalmology department of a single-site hospital.

BACKGROUND: Anesthesia-controlled time (ACT) generally refers to the time durations before and after the period of surgery. The ACT is typically dependent on the sequence of 2 consecutive surgeries and thus adds to the complexity of operating room scheduling. We report a study on sequence-dependent ACTs at the West China Hospital (WCH), focusing on elective surgeries (also referred to as "procedures" below) performed by the ophthalmology department of WCH over a 5-year period, 2007 to 2012. METHODS: ACTs associated with 4 high-volume procedures: phacoemulsification, vitrectomy, strabismus correction, and glaucoma filtration. A total of 29,452 cases were studied, classified into 4 groups according to the sequence of the procedures involved. Specifically, P-P plots were used to determine the distributions of the ACTs, Kruskal-Wallis H test, Nemenyi test, and Student t test were performed to examine the sequence-dependent nature of the ACTs, and the t test was also applied to examine the advantage of sequencing the same procedures consecutively. Permutations were enumerated to identify the best sequence when different procedures were involved. Monte Carlo simulation was used to compute the total completion time, ACTs plus surgical periods, of any given sequence of procedures. RESULTS: We confirm via statistical tests that the ACTs follow lognormal distributions, and identify their corresponding means and variances. Furthermore, we verify that the ACTs are statistically different in means: they are sequence dependent in general. Using statistical tests, we conclude that it is best to sequence identical procedures consecutively, and we also identify the best sequence involving different procedures. Using Monte Carlo simulation, we compared the daily completion times using the best sequences we have identified against actual data from WCH over a 2-year period; the average reduction is 4.7% (with a standard error (SE) of ± ± 0.5%). CONCLUSIONS: ACTs are usually sequence dependent and hence should be considered in operating room scheduling. Although identifying the best sequence in general is a difficult optimization problem, in certain departments (such as the ophthalmology department of WCH) where a set of high-volume small-variety procedures is present, the best sequences can be systematically identified using a combination of statistical tests and Monte Carlo simulation as illustrated in this study.

[Influence of intraoperative cervical posture in single segmental cervical disc replacement on restoration of cervical curve in neutral position].

OBJECTIVE: To study the correlation between the cervical posture in the cervical disc replacement (CDR). METHODS: Between January 2008 and August 2010, 51 and the cervical curve restoration in neutral position after surgery. patients underwent single segmental PRESTIGE LP replacement, and the clinical data were retrospectively analyzed. During the surgery, the patient was supinely placed and the lordosis of the cervical spine was mantained with a pillow placed beneath the neck. Of them, 28 were male and 23 were female, aged 30-64 years (mean, 45 years); 32 were diagnosed as having cervical spondylotic myelopathy, 7 having radiculopathy, and 12 having myelopathy and radiculopathy. The disease duration was 3-48 months (mean, 15 months). CDR was performed at C(4, 5) in 5 cases, at C(5, 6) in 42 cases, and at C(6, 7) in 4 cases. The Cobb angles of the cervical alignment, targeted functional spinal unit (FSU), and targeted disc were measured by sagittal X-ray film of the cervical spine in neutral position before and after surgery, as well as the intraoperative C-arm fluroscopy of the cervical spine. Linear correlation and regression were performed to analyze the relation between cervical Cobb angle difference at intraoperation and improvement of the Cobb angles at 3 months after operation. RESULTS: The cervical Cobb angles at intraoperation and 3 months after operation were larger than those at preoperation (P < 0.05). The difference of the Cobb angle between intra- and pre-operation was (6.72 +/- 9.13) degrees on cervical alignment, (2.10 +/- 5.12) degrees on targeted FSU, and (3.33 +/- 3.75) degrees on targeted disc. At 3 months after operation, the Cobb angle improvement of the cervical alignment, targeted FSU, and targeted disc was (6.30 +/- 7.28), (3.99 +/- 5.37), and (4.29 +/- 5.36) degrees, respectively. There was no significant difference in the Cobb angle improvement between the targeted FSU and the targeted disc (t = -4.391, P = 0.698), and between the targeted disc and the cervical alignment (t = -1.917, P = 0.061), but significant difference was found between the targeted FSU and the cervical alignment (t = -2.623, P = 0.012). The linear correlation between the Cobb angle difference and the Cobb angle improvement of the cervical spine was observed (P < 0.05). CONCLUSION: A slightly lordotic cervical posture during CDR is an important factor to maintaining normal physiological lordosis of the cervical spine after surgery.

[The role of CD14 promoter - 159 C-> T polymorphism on changes of serum lipid ratios induced by high-carbohydrate/low-fat diets in healthy Chinese Han youth].

OBJECTIVE: To investigate the role of CD14 promoter - 159 C-> T polymorphism on ratios of serum lipids and its interaction on the ratios with a high-carbohydrate/low-fat (HC/LF) diet in a young and healthy Chinese Han population. METHODS: After a washout diet for seven days, fifty six healthy young subjects (22.89 +/- 1.80 years) were given the HC/LF diet for six days. Twelve-hour fasting venous blood samples were collected in the mornings of the first, the eighth and the fourteenth days. The serum lipid profiles and the CD14 -159 C->T polymorphism were analyzed. The ratios of triglyceride/high density lipoprotein-cholesterol (TG/HDL-c), log (TG/HDL-c), total cholesterol/high density lipoprotein-cholesterol (TC/HDL-c) and low density lipoprotein-cholesterol/high density lipoprotein-cholesterol (LDL-c/HDL-c) were calculated. RESULTS: The male carriers of the C allele had significantly higher TG/HDL-c and log (TG/HDL-c) than the female carriers at baseline, after the washout diet and after the HC/LF diet, higher TC/HDL-c at baseline and after the washout diet, and higher LDL-c/HDL-c only after the washout diet. The female subjects with the TT genotype had higher TG/HDL-c and log (TG/HDL-c) than the female carriers of the C allele at baseline, after the washout diet and after the HC/LF diet, higher LDL-c/HDL-c at baseline and after the HC/LF diet, and higher TC/HDL-c only after the washout diet. Compared with that before the HC/LF diet, TC/HDL-c was significantly decreased after the HC/LF diet regardless of gender and the genotype of the CD14 -159 polymorphism. LDL-c/HDL-c was significantly decreased in both the male and female carriers of the C allele. TG/HDL-c and log (TG/HDL-c) were significantly increased only in the female carriers of the C allele. CONCLUSION: In the subjects with C allele, the HC/LF diet is a minor factor and its effects on the lipid ratios can be masked by the effects of the C allele at CD14 -159. The interaction between the HC/LF diet and the C allele at CD14 -159 can decrease LDL-c/HDL-c in both males and females and increase TG/ HDL-c and log (TG/HDL-c) in the females.

[Effects of a high-carbohydrate diet on the serum lipid and apolipoprotein ratios in healthy young adults with different genotypes of APOA1 -75 G/A polymorphism].

OBJECTIVE: To investigate the effects of a high-carbohydrate diet on the lipid and apolipoprotein ratios in healthy young adults with different genotypes of the polymorphism at -75 site in the promoter region of the gene of apolipoprotein AI (APOA1). METHODS: Fifty-six subjects aged (22.89 +/- 1.80) years were given a wash-out diet for 7 days, followed by a high-carbohydrate diet for 6 days. The wash-out diet contained 15% protein, 31% fat, and 54% carbohydrate. The high-carbohydrate diet contained 15% protein, 15% fat, and 70% carbohydrate. Twelve-hour fasting serum lipids and apolipoproteins B100 and AI were measured on the mornings of the 1st, the 8th, and the 14th days from the beginning of the wash-out diet. The ratios of triglyceride (TG)/high-density lipoprotein cholesterol (HDL-C), total cholesterol (TC)/HDL-C, low-density lipoprotein cholesterol (LDL-C)/HDL-C, and apolipoprotein B100 (APOB100)/apolipoprotein AI (APOAI) were calculated. The genome DNA was extracted and the polymorphism of APOA1 -75 G/A was determined by polymerase chain reaction followed by restriction fragment length polymorphism assay. RESULTS: At baseline, the lipid and apolipoprotein ratios showed no significant differences between the GG genotype and the A carriers in males (P > 0.05), whereas the female A carriers had a significantly higher ratio of LDL-C/ HDL-C compared with the female subjects with the GG genotype (P < 0.05). Following the high-carbohydrate diet, significant decreases of TC/HDL-C were found in all the groups, regardless of sex and genotype (P < 0.01). LDL-C/HDL-C experienced significant decreases in both the genotypes in males (P < 0.05), while in females, significant decrease of LDL-C/HDL-C was only observed in A carriers (P < 0.01). CONCLUSION: The A allele of the -75 G/A polymorphism in APOA1 may have specific effects on the LDL-C/HDL-C ratio in females.

[Effects of a low-fat and high-carbohydrate diet on the physiological and biochemical indices in healthy youth with different body mass index].

OBJECTIVE: To investigate the effects of a low-fat and high-carbohydrate (LF-HC) diet on the physiological and biochemical indexes in healthy youth with different body mass index (BMI). METHODS: Seven overweight participants [BMI=(27.82 +/- 1.64) kg/m2] and 49 age-matched controls [BMI = (20.06 +/- 2.41) kg/ m2] were given a washout diet for 7 d, followed by a LF-HC diet for 6 d. The washout diet contained 31.1% fat and 54.1% carbohydrate, and the LF-HC diet contained 14.8% fat and 70.1% carbohydrate of total energy. Anthropometric measurements were conducted on the mornings of the first, eighth and fourteenth days. Serum samples were prepared from twelve-hour fasting venous blood. Biochemical indexes including lipids; glucose and insulin were measured with routine methods. The homeostasis model assessment of insulin resistance (HOMA-IR) was calculated. RESULTS: At baseline, the control group had lower levels of body mass (P = 0.000), BMI (P = 0.000), waist-hip ratio (P = 0.000), systolic blood pressure (P = 0.001), diagnostic blood pressure (P = 0.016) and triglycerides (P = 0.006), and a higher level of HDL cholesterol (P = 0.005) than the overweight group. When compared with those before the ILF-HC diet, total cholesterol (P < 0.05) and LDL cholesterol (P < 0.05) decreased, and insulin (P < 0.05) and HOMA-IR (P < 0.05) increased in both the control group and the overweight group after the LF-HC diet. Increased triglycerides (P = 0.000) were observed only in the control subjects, and HDL cholesterol (P = 0.018) increased only in the overweight subjects after the LF-HC diet. CONCLUSION: The responses of serum TG and HDL-C to the LF-HC diet are related to BMI in healthy youth.