Optimizing Algorithm for Existing Fiber-Optic Displacement Sensor Performance.

This paper describes the optimal design of a miniature fiber-optic linear displacement sensor. It is characterized by its ability to measure displacements along a millimetric range with sub-micrometric resolution. The sensor consists of a triangular reflective grating and two fiber-optic probes. The measurement principle of the sensor is presented. The design of the sensor's triangular grating has been geometrically optimized by considering the step angle of the grating to enhance the sensor's resolution. The optimization method revealed a global optimum at which the highest resolution is obtained.

Deep Learning Transformer Models for Building a Comprehensive and Real-time Trauma Observatory: Development and Validation Study.

BACKGROUND: Public health surveillance relies on the collection of data, often in near-real time. Recent advances in natural language processing make it possible to envisage an automated system for extracting information from electronic health records. OBJECTIVE: To study the feasibility of setting up a national trauma observatory in France, we compared the performance of several automatic language processing methods in a multiclass classification task of unstructured clinical notes. METHODS: A total of 69,110 free-text clinical notes related to visits to the emergency departments of the University Hospital of Bordeaux, France, between 2012 and 2019 were manually annotated. Among these clinical notes, 32.5% (22,481/69,110) were traumas. We trained 4 transformer models (deep learning models that encompass attention mechanism) and compared them with the term frequency-inverse document frequency associated with the support vector machine method. RESULTS: The transformer models consistently performed better than the term frequency-inverse document frequency and a support vector machine. Among the transformers, the GPTanam model pretrained with a French corpus with an additional autosupervised learning step on 306,368 unlabeled clinical notes showed the best performance with a micro F1-score of 0.969. CONCLUSIONS: The transformers proved efficient at the multiclass classification of narrative and medical data. Further steps for improvement should focus on the expansion of abbreviations and multioutput multiclass classification.

Comparison of two infant cardiopulmonary resuscitation techniques explained by phone in a non-health professionals' population: Two-thumbs encircling hand technique vs. two-fingers technique, a randomised crossover study in a simulation environment.

BACKGROUND: Paediatric out-of-hospital cardiac arrest (OHCA) is the reason for an emergency call in approximately 8/100,000 person-years. Improvement of OHCA resuscitation needs a quality chain of survival and a rapid start of resuscitation. The aim of this study was to compare the efficacy of two resuscitation techniques provided on a mannequin, the two-fingers technique (TFT) and the two-thumbs encircling hand technique (TTHT), explained by a trained emergency call responder on the phone in a population of non-health professionals. METHODS: We conducted a randomised crossover study in the simulation lab of a University Hospital. The participants included in the study were non-health professional volunteers of legal age. The participants were assigned (1:1 ratio) to two groups: group A: TFT then TTHT, group B: TTHT then TFT. Scenario and techniques were discovered during the evaluation. RESULTS: Thirty-five volunteers were randomised before the sessions and 33 ultimately came to the simulation lab. We found a better median QCPR global score during TTHT sessions than during TFT sessions (74 vs. 59, P = 0.046). Linear mixed models showed that the TTHT method was the only variable associated with a better QCPR global score [model 1: ß = 14.3; 95% confidence interval (CI), 2.4-26.2; model 2: ß = 14.5; 95% CI, 2.5-26.6]. CONCLUSION: Our study showed the superiority of TTHT for infant CPR performed by non-health professionals when an emergency call responder advised them over the phone. It seemed to be the best technique for a solo rescuer regardless of previous training.

Investigation of Surface Integrity Induced by Various Finishing Processes of AISI 52100 Bearing Rings.

Surface integrity induced by finishing processes significantly affects the functional performance of machined components. In this work, three kinds of finishing processes, i.e., precision hard turning, conventional grinding, and sequential grinding and honing, were used for the finish machining of AISI 52100 bearing steel rings. The surface integrity induced by these finishing processes was studied via SEM investigations and residual stress measurements. To investigate rolling contact fatigue performance, contact fatigue tests were performed on a twin-disc testing machine. As the main results, the SEM observations show that precision hard turning and grinding introduce microstructural alterations. Indeed, in precision hard turning, a fine white layer (<1 µm) is observed on the top surface, followed by a thermally affected zone in the subsurface, and in grinding only, a white layer with 5 µm thickness is observed. However, no microstructural changes are found after sequential grinding and honing processes. White layers induced by precision hard turning and grinding possess compressive residual stresses. Grinding and sequential grinding and honing processes generate similar residual stress distributions, which are maximum and compressive at the machined surface and tensile at the subsurface depth of 15 µm. Precision hard turning generates a "hook"-shaped residual stress profile with maximum compressive value at the subsurface depth and thus contributes as a prenominal factor to the obtainment of the longest fatigue life with respect to other finishing processes. Due to the high quality of surface roughness (Ra = 0.05 µm), honing post grinding improves the fatigue life of bearing rings by 2.6 times in comparison with grinding. Subsurface compressive residual stresses, as well as low surface roughness, are key parameters for extending bearing fatigue life.

Trends in reasons for emergency calls during the COVID-19 crisis in the department of Gironde, France using artificial neural network for natural language classification.

OBJECTIVES: During periods such as the COVID-19 crisis, there is a need for responsive public health surveillance indicators in order to monitor both the epidemic growth and potential public health consequences of preventative measures such as lockdown. We assessed whether the automatic classification of the content of calls to emergency medical communication centers could provide relevant and responsive indicators. METHODS: We retrieved all 796,209 free-text call reports from the emergency medical communication center of the Gironde department, France, between 2018 and 2020. We trained a natural language processing neural network model with a mixed unsupervised/supervised method to classify all reasons for calls in 2020. Validation and parameter adjustment were performed using a sample of 39,907 manually-coded free-text reports. RESULTS: The number of daily calls for flu-like symptoms began to increase from February 21, 2020 and reached an unprecedented level by February 28, 2020 and peaked on March 14, 2020, 3 days before lockdown. It was strongly correlated with daily emergency room admissions, with a delay of 14 days. Calls for chest pain and stress and anxiety, peaked 12 days later. Calls for malaises with loss of consciousness, non-voluntary injuries and alcohol intoxications sharply decreased, starting one month before lockdown. No noticeable trends in relation to lockdown was found for other groups of reasons including gastroenteritis and abdominal pain, stroke, suicide and self-harm, pregnancy and delivery problems. DISCUSSION: The first wave of the COVID-19 crisis came along with increased levels of stress and anxiety but no increase in alcohol intoxication and violence. As expected, call related to road traffic crashes sharply decreased. The sharp decrease in the number of calls for malaise was more surprising. CONCLUSION: The content of calls to emergency medical communication centers is an efficient epidemiological surveillance data source that provides insights into the societal upheavals induced by a health crisis. The use of an automatic classification system using artificial intelligence makes it possible to free itself from the context that could influence a human coder, especially in a crisis situation. The COVID-19 crisis and/or lockdown induced deep modifications in the population health profile.

Assessment of the SpO2/FiO2 ratio as a tool for hypoxemia screening in the emergency department.

OBJECTIVE: We assessed the performance of the ratio of peripheral arterial oxygen saturation to the inspired fraction of oxygen (SpO2/FiO2) to predict the ratio of partial pressure arterial oxygen to the fraction of inspired oxygen (PaO2/FiO2) among patients admitted to our emergency department (ED) during the SARS-CoV-2 outbreak. METHODS: We retrospectively studied patients admitted to an academic-level ED in France who were undergoing a joint measurement of SpO2 and arterial blood gas. We compared SpO2 with SaO2 and evaluated performance of the SpO2/FiO2 ratio for the prediction of 300 and 400 mmHg PaO2/FiO2 cut-off values in COVID-19 positive and negative subgroups using receiver-operating characteristic (ROC) curves. RESULTS: During the study period from February to April 2020, a total of 430 arterial samples were analyzed and collected from 395 patients. The area under the ROC curves of the SpO2/FiO2 ratio was 0.918 (CI 95% 0.885-0.950) and 0.901 (CI 95% 0.872-0.930) for PaO2/FiO2 thresholds of 300 and 400 mmHg, respectively. The positive predictive value (PPV) of an SpO2/FiO2 threshold of 350 for PaO2/FiO2 inferior to 300 mmHg was 0.88 (CI95% 0.84-0.91), whereas the negative predictive value (NPV) of the SpO2/FiO2 threshold of 470 for PaO2/FiO2 inferior to 400 mmHg was 0.89 (CI95% 0.75-0.96). No significant differences were found between the subgroups. CONCLUSIONS: The SpO2/FiO2 ratio may be a reliable tool for hypoxemia screening among patients admitted to the ED, particularly during the SARS-CoV-2 outbreak.

Impact des deux confinements sur le recours aux soins d'urgence lors de l'épidémie de COVID-19 en Nouvelle-Aquitaine.

INTRODUCTION: Following the emergence of the COVID-19 epidemic in France, several preventive measures have been put in place, including a mandatory lockdown of the entire population. This measure was intended to slow down the viral circulation and protect the healthcare system, especially hospital departments. The aim of this study was to describe the activity of emergency department (ED) during the two lockdowns related to the COVID-19 epidemic in the Nouvelle-Aquitaine region. METHOD: A retrospective descriptive analysis of ED visits was performed for the period December 09, 2019 to December 20, 2020. The distribution of the number of ED visits was studied. RESULTS: ED visits decreased by 50% during the first lockdown in line with the COVID-19 epidemic and by 30% during the second. Hospitalization rate increased during the two lockdowns (+ 48% and + 20%, respectively). A differentiated use was observed during both lockdowns, with the emergence of the use of care for "coronavirus", "stroke" or "dyspnea / respiratory failure" while the typical pathologies "ENT infections" or "skin infections" were no more or less observed. CONCLUSION: Data from Oscour® allowed a real-time monitoring of the COVID-19 epidemic in France, and to assess the impact of lockdown on ED activity in the region. A decline in the use of healthcare services, the increase in hospitalization rate and the pathologies observed during the two lockdowns are in favour of a refocusing of the recourse for most serious pathologies.

Stress and lasting symptoms following injury: Results from a 4-month cohort of trauma patients recruited at the emergency department.

INTRODUCTION: Recent research suggests that up to 20% of minor trauma patients admitted to the emergency department (ED) will suffer from non-specific chronic conditions over the subsequent several months. Thus, the present study assessed the correlates of symptoms that persisted at 4 months after an ED visit and, in particular, evaluated the associations between these symptoms and self-reported stress levels at ED admission and discharge. METHOD: This study was a prospective observational investigation conducted in the ED of Bordeaux University Hospital that included patients admitted for minor trauma. All participants were contacted by phone 4 months after presentation at the ED to assess the occurrence of post-concussion-like symptoms (PCLS). RESULTS: A total of 193 patients completed the follow-up assessment at 4 months; 5.2% of the participants suffered from post-traumatic stress disorder (PTSD) and 24.5% suffered from PCLS. A multivariate analysis revealed an association between PCLS and stress level at discharge from the ED (odds ratios [OR]: 2.85, 95% confidence interval [CI]: 1.10-7.40). CONCLUSIONS: The risk of PCLS at 4 months after an ED visit for a minor injury increased in association with the level of stress at discharge from the ED. These results may improve the quality of life for the millions of patients who experience a stressful injury event every year.

Fibrinolysis in trauma patients: wide variability demonstrated by the Lysis Timer.

Hyperfibrinolysis contributes to the pathophysiology of trauma-induced coagulopathy. At present, systematic administration of tranexamic acid (TXA) is recommended in all patients in the early phase of trauma. However, there is some debate regarding whether TXA is beneficial in all trauma patients. A rapid and accurate tool to diagnose hyperfibrinolysis may be useful for tailoring TXA treatment. We conducted a proof-of-concept study of consecutive adult trauma patients. A first blood sample was obtained at the time of pre-hospital care (T1). Patients received 1 g of TXA after T1. A second sample was obtained on arrival at the emergency unit (T2). We examined coagulation, fibrin and fibrinogen formation and degradation. Fibrinolysis was assessed by determining tissue plasminogen activator (t-PA) antigen and plasminogen activator inhibitor 1 (PAI-1) activity and global fibrinolysis capacity assay using a device developed by Hyphen BioMed: the Lysis Timer (GFC/LT). The study population consisted of 20 patients (42 ± 21 years, index of severity score 32 ± 21). Both coagulation and fibrinolysis were altered at T1. GFC/LT values exhibited hyperfibrinolysis only in five patients. Principal component analysis carried out at T1 showed two main axes of alteration. The major axis was related to coagulation, altered in all patients, while the second axis was related to fibrinolysis. GFC/LT was mainly influenced by PAI-1 activity while fibrin monomers were related to the severity of trauma. At T2, GFC/LT exhibited the marked effect of TXA on clot lysis time. In conclusion, GFC/LT demonstrated huge variation in the fibrinolytic response to trauma.

Prevention of post-concussion-like symptoms in patients presenting at the emergency room, early single eye movement desensitization, and reprocessing intervention versus usual care: study protocol for a two-center randomized controlled trial.

BACKGROUND: Recent data suggest that 10-20% of injury patients will suffer for several months after the event from diverse symptoms, generally referred to as post-concussion-like symptoms (PCLS), which will lead to a decline in quality of life. A preliminary randomized control trial suggested that this condition may be induced by the stress experienced during the event or emergency room (ER) stay and can be prevented in up to 75% of patients with a single, early, short eye movement desensitization and reprocessing (EMDR) psychotherapeutic session delivered in the ER. The protocol of the SOFTER 3 study was designed to compare the impact on 3-month PCLS of early EMDR intervention and usual care in patients presenting at the ER. Secondary outcomes included 3-month post-traumatic stress disorder, 12-month PCLS, self-reported stress at the ER, self-assessed recovery expectation at discharge and 3 months, and self-reported chronic pain at discharge and 3 months. METHODS: This is a two-group, open-label, multicenter, comparative, randomized controlled trial with 3- and 12-month phone follow-up for reports of persisting symptoms (PCLS and post-traumatic stress disorder). Those eligible for inclusion were adults (≥18 years old) presenting at the ER departments of the University Hospital of Bordeaux and University Hospital of Lyon, assessed as being at high risk of PCLS using a three-item scoring rule. The intervention groups were a (1) EMDR Recent Traumatic Episode Protocol intervention performed by a trained psychologist during ER stay or (2) usual care. The number of patients to be enrolled in each group was 223 to evidence a 15% decrease in PCLS prevalence in the EMDR group. DISCUSSION: In 2012, the year of the last national survey in France, 10.6 million people attended the ER, some of whom did so several times since 18 million visits were recorded in the same year. The SOFTER 3 study therefore addresses a major public health challenge. TRIAL REGISTRATION: Clinical Trials. NCT03400813 . Registered 17 January 2018 - retrospectively registered.

Emergency room intervention to prevent post concussion-like symptoms and post-traumatic stress disorder. A pilot randomized controlled study of a brief eye movement desensitization and reprocessing intervention versus reassurance or usual care.

Up to 20% of patients presenting at an emergency room (ER) after a stressful event will for several months suffer from very diverse long-lasting symptoms and a potentially significant decline in quality of life, often described as post concussion-like symptoms (PCLS). The objectives of our randomized open-label single-center study were to assess the feasibility of psychologist-led interventions in the context of the ER and to compare the effect of eye movement desensitization and reprocessing (EMDR) with reassurance and usual care. Conducted in the ER of Bordeaux University Hospital, the study included patients with a high risk of PCLS randomized in three groups: a 15-min reassurance session, a 60-min session of EMDR, and usual care. Main outcomes were the proportion of interventions that could be carried out and the prevalence of PCSL and post-traumatic stress disorder (PTSD) three months after the ER visit. One hundred and thirty patients with a high risk of PCLS were randomized. No logistic problem or patient refusal was observed. In the EMDR, reassurance and control groups, proportions of patients with PCLS at three months were 18%, 37% and 65% and those with PTSD were 3%, 16% and 19% respectively. The risk ratio for PCLS adjusted for the type of event (injury, non-injury) for the comparison between EMDR and control was 0.36 [95% CI 0.20-0.66]. This is the first randomized controlled trial that shows that a short EMDR intervention is feasible and potentially effective in the context of the ER. The study was registered at ClinicalTrials.gov (NCT03194386).

Forced vital capacity assessment for risk stratification of blunt chest trauma patients in emergency settings: A preliminary study.

OBJECTIVE: The aim of this study was to assess the performance of Forced Vital Capacity (FVC) for prediction of secondary respiratory complications in blunt chest trauma patients. METHODS: During a 15-month period, all consecutive blunt chest trauma patients admitted in our emergency intensive care unit with more than 3 rib fractures were eligible, unless they required mechanical ventilation in the prehospital or emergency settings. FVC was measured at admission and at emergency discharge after therapeutic interventions. The main outcome was the occurrence of secondary respiratory complications defined by hospital-acquired pulmonary infection, secondary admission in the intensive care unit or mechanical ventilation for respiratory failure or death. The performance of FVC for prediction of secondary respiratory complications was assessed by receiver operating characteristic (ROC) curve and multivariate analysis after logistic regression. RESULTS: Sixty-two consecutive patients were included and 13 (21%) presented secondary respiratory complications. Only FVC measured at emergency discharge - not FCV at admission - was significantly lower in patients who developed secondary respiratory complications (44±15 vs. 61±20%, P=0.002). The area under the ROC curves for FCV in predicting secondary pulmonary complications was 0.79 [95% CI: 0.66-0.88], P=0.0001. An FVC at discharge≤50% was independently associated with the occurrence of secondary complications with an OR at 7.9 [1.9-42.1], P=0.004. CONCLUSION: The non-improvement of FVC≤50% at emergency discharge is associated with secondary respiratory complications and should prevent the under-triage of patients with no sign of respiratory failure at admission.

Bundle of care for blunt chest trauma patients improves analgesia but increases rates of intensive care unit admission: A retrospective case-control study.

INTRODUCTION: This single-centre retrospective case-control study aimed to assess the effectiveness of a multidisciplinary clinical pathway for blunt chest trauma patients admitted in emergency department (ED). PATIENTS AND METHODS: All consecutive blunt chest trauma patients with more than 3 rib fractures and no indication of mechanical ventilation were compared to a retrospective cohort over two 24-month periods, before and after the introduction of the bundle of care. Improvement of analgesia was the main outcome investigated in this study. The secondary outcomes were the occurrence of secondary respiratory complications (pneumonia, indication for mechanical ventilation, secondary ICU admission for respiratory failure or death), the intensive care unit (ICU) and hospital length of stay (LOS). RESULTS: Sixty-nine pairs of patients were matched using a 1:1 nearest neighbour algorithm adjusted on age and indices of severity. Between the two periods, there was a significant reduction of the rate of uncontrolled analgesia (55 vs. 17%, P<0.001). A significant increase in the rate of primary ICU transfer during the post-protocol period (23 vs. 52%, P<0.001) was not associated with a reduction of secondary respiratory complications or a reduction of ICU or hospital LOS. Only the use of non-steroidal anti-inflammatory drugs appeared to be associated with a significant reduction of secondary respiratory complications (OR=0.3 [0.1-0.9], P=0.03). CONCLUSION: Implementation of a multidisciplinary clinical pathway significantly improves pain control after ED management, but increases the rate of primary ICU admission without significant reduction of secondary respiratory complications.

Vital Capacity Impairment due to Neuromuscular Disease and its Correlation with Diaphragmatic Ultrasound: A Preliminary Study.

The purpose of this pilot study was to evaluate the correlation between diaphragmatic excursion measured by a right sub-costal ultrasound approach and forced vital capacity in patients with amyotrophic lateral sclerosis (ALS) or myotonic dystrophy (MD). All patients referred for pulmonary function testing underwent ultrasonic measurement of diaphragmatic excursion during quiet breathing, voluntary sniffing (Esniff) and forced breathing (EDEmax). Forty-five patients were included, mainly for amyotrophic lateral sclerosis or myotonic dystrophy. There was a significant correlation between EDEmax values and forced vital capacity (FVC) values (r = 0.68 [0.46­0.90], p < 0.0001) and between EDEmax values and percentage of predicted FVC values (r = 0.75 [0.55­0.95], p < 0.0001). At a threshold of EDEmax < 5.5 cm, the sensitivity and specificity of ultrasonic diaphragmatic excursion in predicting FVC ≤ 50% of theoretical values were 100% [66%­100%] and 69% [52%­84%] respectively, without any significant difference between males and females. There was no statistical correlation between maximal inspiratory pressure and Esniff.

Noninvasive assessment of macrovesicular liver steatosis in cadaveric donors based on computed tomography liver-to-spleen attenuation ratio.

Fatty liver disease, including liver steatosis, is a major health problem worldwide. In liver transplantation, macrovesicular steatosis in donor livers is a major cause of graft failure and remains difficult to assess. On one hand, several imaging modalities can be used for the assessment of liver fat, but liver biopsy, which is still considered the gold standard, may be difficult to perform in this context. On the other hand, computed tomography (CT) is commonly used by teams managing cadaveric donors to assess donors and to minimize the risk of complications in recipients. The purpose of our study was to validate the use of CT as a semiquantitative method for assessing macrovesicular steatosis in cadaveric donors with liver biopsy as a reference standard. A total of 109 consecutive cadaveric donors were included between October 2009 and May 2011. Brain death was diagnosed according to French legislation. Liver biopsy and then CT were performed on the same day to determine the degree of macrovesicular steatosis. All liver biopsies and CT scans were analyzed in a double-blinded fashion by a senior pathologist and a senior radiologist, respectively. For CT, we used the liver-to-spleen (L/S) attenuation ratio, which is a validated method for determining 30% or greater steatosis in living liver donors. Fourteen of 109 biopsies exhibited macrovesicular steatosis > 30% upon histologic analysis. A receiver operating characteristic curve was generated for the L/S ratio to identify its ability to predict significant steatosis, which was defined as >30%. A cutoff value of 0.9 for the CT L/S ratio provided a sensitivity of 79% and a specificity of 97% to detect significant steatosis.

Goal-directed ultrasound in emergency medicine: evaluation of a specific training program using an ultrasonic stethoscope.

OBJECTIVE: This observational study aimed to define the learning curve in goal-directed ultrasound (US) after a 2-day training course dedicated to novice emergency residents. MATERIALS AND METHODS: After completion of the training program, 180 patients requiring goal-directed US examination were examined by a resident and by an experienced investigator. The main endpoints were the diagnostic agreement between the two operators for 14 clinical questions, the duration of the examinations, the number of nonaddressed questions, and the final diagnosis. All criteria were analyzed according to the experience of the resident every 10 examinations. RESULTS: After 30 supervised examinations, residents adequately assessed with a very good or considerable agreement global left ventricular systolic dysfunction [κ=0.92; 95% confidence interval (CI): 0.80-1], severe right ventricular dilation (κ=0.73; 95% CI: 0.37-1), inferior vena cava diameter (κ=0.88; 95% CI: 0.71-1), and pericardial effusion (κ=0.85; 95% CI: 0.55-1). In general US, 20 supervised examinations were required to diagnose intraperitoneal effusion (κ=0.81; 95% CI: 0.61-1), cholelithiasis (κ=0.73; 95% CI: 0.36-1), obstructive uropathy (κ=0.85; 95% CI: 0.56-1), bladder distention (κ=1; 95% CI: 1-1), abdominal aortic aneurism (κ=0.9; 95% CI: 0.74-1), alveolar interstitial pattern (κ=0.87; 95% CI: 0.74-0.99), consolidated lung (κ=0.83; 95% CI: 0.68-0.97), or pleural effusion (κ=0.89; 95% CI: 0.77-1). After 30 supervised examinations, the overall diagnostic accuracy was judged excellent between the two investigators, with a significant improvement during the learning curve. CONCLUSION: The performance of 30 supervised and goal-oriented examinations appeared adapted to adequately answer clinical questions covered by core applications of emergency US.

Benefits of intravenous lidocaine on post-operative pain and acute rehabilitation after laparoscopic nephrectomy.

BACKGROUND AND AIMS: Intravenous (I.V.) lidocaine has analgesic, antihyperalgesic and anti-inflammatory properties and is known to accelerate the return of bowel function after surgery. We evaluated the effects of I.V. lidocaine on pain management and acute rehabilitation protocol after laparoscopic nephrectomy. MATERIALS AND METHODS: A total of 47 patients scheduled to undergo laparoscopic nephrectomy were included in a two-phase observational study where I.V. lidocaine (1.5 mg/kg/h) was introduced, in the second phase, during surgery and for 24 h post-operatively. All patients underwent the same post-operative rehabilitation program. Post-operative pain scores, opioid consumption and extent of hyperalgesia were measured. Time to first flatus and 6 min walking test (6MWT) were recorded. RESULTS: Patient demographics were similar in the two phases (n = 22 in each group). Lidocaine significantly reduced morphine consumption (median [25-75% interquartile range]; 8.5 mg[4567891011121314151617] vs. 25 mg[1920212223242526272829303132]; P < 0.0001), post-operative pain scores (P < 0.05) and hyperalgesia extent on post-operative day 1-day 2-day 4 (mean ± standard deviation (SD); 1.5 ± 0.9 vs. 4.3 ± 1.2 cm (P < 0.001), 0.6 ± 0.5 vs. 2.8 ± 1.2 cm (P < 0.001) and 0.13 ± 0.3 vs. 1.2 ± 1 cm (P < 0.001), respectively). Time to first flatus (mean ± SD; 29 ± 7 h vs. 48 ± 15 h; P < 0.001) and 6MWT at day 4 (189 ± 50 m vs. 151 ± 53 m; P < 0.001) were significantly enhanced in patients with i.v. lidocaine. CONCLUSION: Intravenous (I.V.) lidocaine could reduce post-operative morphine consumption and improve post-operative pain management and post-operative recovery after laparoscopic nephrectomy. I.V. lidocaine could contribute to better post-operative rehabilitation.

Relevance of roughness parameters of surface finish in precision hard turning.

Precision hard turning is a process to improve the surface integrity of functional surfaces. Machining experiments are carried out on hardened AISI 52100 bearing steel under dry condition using c-BN cutting tools. A full factorial experimental design is used to characterize the effect of cutting parameters. As surface topography is characterized by numerous roughness parameters, their relative relevance is investigated by statistical indices of performance computed by combining the analysis of variance, discriminant analysis and the bootstrap method. The analysis shows that the profile Length ratio (Lr) and the Roughness average (Ra) are the relevant pair of roughness parameters which best discriminates the effect of cutting parameters and enable the classification of surfaces which cannot be distinguished by one parameter: low profile length ratio Lr (Lr = 100.23%) is clearly distinguished from an irregular surface corresponding to a profile length ratio Lr (Lr = 100.42%), whereas the roughness average Ra values are nearly identical.