Ultrasound assessment of gastric contents in children before general anaesthesia for acute appendicitis.

There is increasing evidence that a minority of adults with acute appendicitis have gastric contents, posing an increased risk of pulmonary aspiration. This study aimed to evaluate the proportion of children with acute appendicitis who have gastric contents considered to pose a higher risk of pulmonary aspiration. We analysed point-of-care gastric ultrasound data routinely collected in children before emergency appendicectomy in a specialist paediatric hospital over a 30-month period. Based on qualitative and quantitative antral assessment in the supine and right lateral decubitus positions, gastric contents were classified as 'higher-risk' (clear liquid with calculated gastric fluid volume > 0.8 ml.kg-1 , thick liquid or solid) or 'lower-risk' of pulmonary aspiration. The 115 children studied had a mean (SD) age of 11 (3) years; 37 (32%; 95%CI: 24-42%) presented with higher-risk gastric contents, including 15 (13%; 95%CI: 8-21%) with solid/thick liquid contents. Gastric contents could not be determined in 13 children as ultrasound examination was not feasible in the right lateral decubitus position. No cases of pulmonary aspiration occurred. This study shows that gastric ultrasound is feasible in children before emergency appendicectomy. This technique showed a range of gastric content measurements, which could contribute towards defining the risk of pulmonary aspiration.

An elevated respiratory quotient predicts complications after cardiac surgery under extracorporeal circulation: an observational pilot study.

Following cardiac surgery, hyperlactatemia due to anaerobic metabolism is associated with an increase in both morbidity and mortality. We previously found that an elevated respiratory quotient (RQ) predicts anaerobic metabolism. In the present study we aimed to demonstrate that it is also associated with poor outcome following cardiac surgery. This single institution, prospective, observational study includes all those patients that were consecutively admitted to the intensive care unit (ICU) after cardiac surgery with cardiopulmonary bypass, that had also been monitored using pulmonary artery catheter. Data were recorded at admission (H0) and after one hour (H1) including: oxygen consumption ([Formula: see text]), carbon dioxide production ([Formula: see text]), RQ ([Formula: see text]), lactate levels and mixed venous oxygen saturation ([Formula: see text]). The primary endpoint was defined as mortality at 30 days. Comparison of the area under the curve (AUC) for receiver operating characteristic curves was used to analyze the prognostic predictive value of RQ, lactate levels and [Formula: see text], in terms of patient outcome. We studied 151 patients admitted to the ICU between May 2015 and February 2016. Seventy eight patients experienced a worse than expected outcome in the post-operative period, and among those seven died. RQ at H1 in non-survivors ([Formula: see text]) was higher than in survivors ([Formula: see text]; p = 0.02). The AUC for RQ to predict mortality was 0.77 (IC95% [0.70-0.84]), with a threshold value of 0.76 (sensitivity 64%, specificity 100%). By comparison, the AUC for lactate levels was significantly superior (AUClact 0.89, IC95% [0.83-0.93], p = 0.02). In this study, elevated RQ appeared to be predictive of mortality after cardiac surgery with CPB.

Hypertonic sodium lactate reverses brain oxygenation and metabolism dysfunction after traumatic brain injury.

BACKGROUND: The mechanisms by which hypertonic sodium lactate (HSL) solution act in injured brain are unclear. We investigated the effects of HSL on brain metabolism, oxygenation, and perfusion in a rodent model of diffuse traumatic brain injury (TBI). METHODS: Thirty minutes after trauma, anaesthetised adult rats were randomly assigned to receive a 3 h infusion of either a saline solution (TBI-saline group) or HSL (TBI-HSL group). The sham-saline and sham-HSL groups received no insult. Three series of experiments were conducted up to 4 h after TBI (or equivalent) to investigate: 1) brain oedema using diffusion-weighted magnetic resonance imaging and brain metabolism using localized 1H-magnetic resonance spectroscopy (n = 10 rats per group). The respiratory control ratio was then determined using oxygraphic analysis of extracted mitochondria, 2) brain oxygenation and perfusion using quantitative blood-oxygenation-level-dependent magnetic resonance approach (n = 10 rats per group), and 3) mitochondrial ultrastructural changes (n = 1 rat per group). RESULTS: Compared with the TBI-saline group, the TBI-HSL and the sham-operated groups had reduced brain oedema. Concomitantly, the TBI-HSL group had lower intracellular lactate/creatine ratio [0.049 (0.047-0.098) vs 0.097 (0.079-0.157); P < 0.05], higher mitochondrial respiratory control ratio, higher tissue oxygen saturation [77% (71-79) vs 66% (55-73); P < 0.05], and reduced mitochondrial cristae thickness in astrocytes [27.5 (22.5-38.4) nm vs 38.4 (31.0-47.5) nm; P < 0.01] compared with the TBI-saline group. Serum sodium and lactate concentrations and serum osmolality were higher in the TBI-HSL than in the TBI-saline group. CONCLUSIONS: These findings indicate that the hypertonic sodium lactate solution can reverse brain oxygenation and metabolism dysfunction after traumatic brain injury through vasodilatory, mitochondrial, and anti-oedema effects.

Reduced mortality by meeting guideline criteria before using recombinant activated factor VII in severe trauma patients with massive bleeding.

BACKGROUND: Management of trauma patients with severe bleeding has led to criteria before considering use of recombinant activated factor VII (rFVIIa), including haemoglobin >8 g dl-1, serum fibrinogen ≥1.0 g l-1, platelets >50,000 x 109 l-1, arterial pH ≥ 7.20, and body temperature ≥34 °C. We hypothesized that meeting these criteria is associated with improved outcomes. METHODS: In this prospective cohort study of 26 French trauma centres, subjects were included if they received rFVIIa for persistent massive bleeding despite appropriate care after severe blunt and/or penetrating trauma. RESULTS: After surgery and/or embolization as haemostatic interventions, 112 subjects received a first dose of 103 µg kg-1 rFVIIa (82-200) (median, 25th-75th percentile) at 420 min (285-647) post-trauma. Of these, 71 (63%) "responders" were still alive at 24h post-trauma and had their transfusion requirements reduced by > 2 packed red blood cell units after rFVIIa treatment. Mortality was 54% on day 30 post-trauma. There were 21%, 44% and 35% subjects who fulfilled 0-1, 2-3 or 4-5, respectively, of the guidelines before receiving rFVIIa. Survival at day 30 was 13%, 49% and 64% and the proportion of responders was 39%, 64% and 82%, when subjects fulfilled 0-1, 2-3 or 4-5 conditions, respectively (both P <0.01). CONCLUSIONS: In actively bleeding trauma patients, meeting guideline criteria before considering rFVIIa was associated with lower mortality and a higher proportion of responders to the rFVIIa.

Reduction of red blood cell transfusion with a patient blood management protocol in urological and visceral surgery: a before-after study.

BACKGROUND: Although Patient Blood Management (PBM) is recommended by international guidelines, little evidence of its effectiveness exists in abdominal surgery. The aim of this study was to evaluate the benefits of the implementation of a PBM protocol on transfusion incidence and anaemia-related outcomes in major urological and visceral surgery. METHODS: In this before-after study, a three-pillar PBM protocol was implemented in 2020-2021 in a tertiary care centre, including preoperative correction of iron-deficiency anaemia, intraoperative tranexamic acid administration, and postoperative restrictive transfusion. A historical cohort (2019) was compared to a prospective cohort (2022) after the implementation of the PBM protocol. The primary outcome was the incidence of red blood cell transfusion intraoperatively or within 7 days after surgery. RESULTS: Data from 488 patients in the historical cohort were compared to 499 patients in the prospective cohort. Between 2019 and 2022, screening for iron deficiency increased from 13.9% to 69.8% (p < 0.01), tranexamic acid administration increased from 9.5% to 84.6% (p < 0.01), and median haemoglobin concentration before transfusion decreased from 77 g.L-1 to 71 g.L-1 (p = 0.02). The incidence of red blood cell transfusion decreased from 11.5% in 2019 to 6.6% in 2022 (relative risk 0.58, 95% CI 0.38-0.87, p = 0.01). The incidence of haemoglobin concentration lower than 100 g.L-1 at discharge was 24.2% in 2019 and 21.8% in 2022 (p = 0.41). The incidence of medical complications was comparable between the groups. CONCLUSION: The implementation of a PBM protocol over a two-year period was associated with a reduction of transfusion in major urological and visceral surgery.

A beat-by-beat, on-line, cardiovascular index, CARDEAN, to assess circulatory responses to surgery: a randomized clinical trial during spine surgery.

Automated assessment of circulatory response to surgical stimuli is unsolved. Would detection of cardiac baroreflex inhibition assess adequacy of intra-operative anti-nociception upon incision, as performed on-line on a beat-by-beat basis by a cardiovascular index, CARDEAN™? 18 ASA I-II patients undergoing spinal disc repair were studied, in a prospective randomized single-blinded trial (observational study). During infusion of propofol to maintain bispectral index between 40 and 60, patients were allocated to receive an effect site target-controlled infusion of remifentanil at Ce = 2 or 4 ng ml(-1). Upon incision and during surgery, circulatory response was assessed using beat-by-beat measurements of minor hypertension and tachycardia to give a cardiovascular index, CARDEAN, scaled between 0 and 100. Upon skin incision, CARDEAN increased in the remifentanil Ce = 2 ng ml(-1) group (n = 7, P < 0.05), while it did not increase in the remifentanil Ce = 4 ng ml(-1) group (n = 7, P = 0.18). During surgery, retrospectively, CARDEAN > 60 was associated with tachycardia and hypertension (P (k) = 0.81 ± 0.10). Changes in CARDEAN appeared linked to adequacy of anti-nociception.

French recommendations for the management of patients with spinal cord injury or at risk of spinal cord injury.

OBJECTIVES: To update the French guidelines on the management of trauma patients with spinal cord injury or suspected spinal cord injury. DESIGN: A consensus committee of 27 experts was formed. A formal conflict-of-interest (COI) policy was developed at the outset of the process and enforced throughout. The entire guidelines process was conducted independently of any industrial funding (i.e. pharmaceutical, medical devices). The authors were advised to follow the rules of the Grading of Recommendations Assessment, Development and Evaluation (GRADE®) system to guide assessment of quality of evidence. The potential drawbacks of making strong recommendations in the presence of low-quality evidence were emphasised. METHODS: The committee studied twelve questions: (1) What are the indications and arrangements for spinal immobilisation? (2) What are the arrangements for pre-hospital orotracheal intubation? (3) What are the objectives of haemodynamic resuscitation during the lesion assessment, and during the first few days in hospital? (4) What is the best way to manage these patients to improve their long-term prognosis? (5) What is the place of corticosteroid therapy in the initial phase? (6) What are the indications for magnetic resonance imaging in the lesion assessment phase? (7) What is the optimal time for surgical management? (8) What are the best arrangements for orotracheal intubation in the hospital environment? (9) What are the specific conditions for weaning these patients from mechanical ventilation for? (10) What are the procedures for analgesic treatment of these patients? (11) What are the specific arrangements for installing and mobilising these patients? (12) What is the place of early intermittent bladder sampling in these patients? Each question was formulated in a PICO (Patients, Intervention, Comparison, Outcome) format and the evidence profiles were produced. The literature review and recommendations were made according to the GRADE® Methodology. RESULTS: The experts' work synthesis and the application of the GRADE method resulted in 19 recommendations. Among the recommendations formalised, 2 have a high level of evidence (GRADE 1+/-) and 12 have a low level of evidence (GRADE 2+/-). For 5 recommendations, the GRADE method could not be applied, resulting in expert advice. After two rounds of scoring and one amendment, strong agreement was reached on all the recommendations. CONCLUSIONS: There was significant agreement among experts on strong recommendations to improve practices for the management of patients with spinal cord injury.

Integrating a pharmacist into an anaesthesiology and critical care department: Is this worthwhile?

Background Operating rooms and Intensive Care Units are places where an optimal management of drugs and medical devices is required. Objective To evaluate the impact of a dedicated pharmacist in an academic Anaesthesiology and Critical Care Department. Setting This study was conducted in the Anaesthesiology and Critical Care Department of Grenoble University Hospital. Method Between November 2013 and June 2017, the drug-related problems occurring in three Intensive Care Units and their corrections by a full-time clinical pharmacist were analyzed using a structured order review instrument. Pharmaceutical costs in the Anaesthesiology and Critical Care Department were analyzed over a 7 year period (2010-2016), during which automated dispensing systems and recurrent meetings to review indications of medications and medical devices were implemented in the department. Main outcome measure Analysis of two issues: correcting drug-related problems and containing pharmaceutical costs. Results A total of 324 drug-related problems were identified. The most frequent problem concerned anti-infective agents (45%), and this was mainly due to the over-dosage of drugs (30%). Dosage adjustments were the most frequent interventions performed by the pharmacist (43%). Over the 7 year period, pharmaceutical costs decreased by 9% (€365,469), while the care activity of the department increased by 55% (+ 12,022 surgical procedures and + 1424 admissions in the ICU). Conclusion Integrating a pharmacist into the Anaesthesiology and Critical Care Department was associated with interventions to correct drug-related problems and containing pharmaceutical costs. Pharmacists should play a central role in such medical environments, to optimize the use of drugs and medical devices.

[Brain perfusion and metabolism imaging techniques]. / Imagerie de la perfusion et du métabolisme cérébral.

Due to recent efforts in improving spatial and temporal resolution in imaging techniques, it is now possible to get relevant information about brain perfusion and metabolism in humans. This information can significantly impact on brain pathophysiology, diagnosis assessment and therapy options, particularly in patients having brain ischemia. Among these imaging and metabolism techniques are dynamic perfusion computed tomography, perfusion MRI, positron emission tomography and NMR spectroscopic imaging. The goal of this article is an overview of these four techniques, with their own technical description, advantages and drawbacks. Details are provided about brain parameters given by each technique and their clinical relevance, the accessibility of the technique in the emergency setting and the optimal window to use it during the patient's evolution.

[Contribution of magnetic resonance spectroscopy in predicting severity and outcome in traumatic brain injury]. / Apport de la spectroscopie RMN à l'évaluation du traumatisme crânien.

Nuclear magnetic spectroscopy (MRS) is a useful method for noninvasively studying intracerebral metabolism. Proton MRS can identify markers of the neuronal viability (N-acetyl-aspartate, NAA), of the metabolism of cellular membranes (choline), of the cellular energy metabolism (creatine, lactate). In Phosphorus MRS, the peaks most readily identified are involved in the high-energy cellular metabolism (ATP, phosphocreatine, inorganic phosphate), and intracellular pH (pHi) can be determined using this method. MRS has been used in experimental models of traumatic brain injury (TBI), primarily to study the cellular metabolism and the relation between biochemical and histological changes after trauma. In trauma patients, significant changes in NAA, choline and pHi were found in both grey and white matter comparing with controls, and these alterations correlated with injury severity. Correlations have been reported between these biochemical changes (reduction in NAA, increase in choline) measured at 1 to 6 months after TBI and the clinical outcome of the patients. However, there are methodological issues which still impede to recommend MRS as a tool for predicting neurological outcome in the clinical setting.

[Thromboprophylaxis in neurosurgery and head trauma]. / Thromboprophylaxie en neurochirurgie et en neurotraumatologie intracrânienne.

The incidence of deep vein thrombosis (DVT) is between 20 and 35% using contrast venography, with a rate of symptomatic DVT between 2.3 and 6% in neurosurgery without any prophylaxis. The risk of DVT is poorly evaluated in head injured patients but is around 5%. Specific risk factors in neurosurgery are: a motor deficit, a meningioma or malignant tumour, a large tumour, age over 60 years, surgery lasting more than 4 hours, a chemotherapy. The benefit of mechanical methods or low molecular weight heparin (LMWH) for the prevention of DVP in neurosurgery is demonstrated (grade A). Each method decreases the risk by about 50%. A postoperative prophylaxis with a LMWH does not seem to increase the risk of intracranial bleeding (grade C). There is no demonstrated benefit to begin a prophylaxis with LMWH before the intervention. The duration of the prophylaxis is 7 to 10 days but this has not been scientifically determined.

[Thromboprophylaxis in elective spinal surgery and spinal cord injury]. / Thromboprophylaxie en chirurgie rachidienne traumatologique et non traumatologique.

The risk of deep vein thrombosis (DVT) after spinal cord injury is very high. Without prophylaxis the incidence of DVT using venography is 81% and the risk of symptomatic DVT is between 12 and 23%. The risk is much lower in elective spine surgery. After discectomy or laminectomy on less than two spine levels, the risk of DVT is less than 1%. After spinal fusion or extended laminectomy, the risk can be estimated between 0.3 and 2.2%. A prophylaxis is recommended for all patients after spinal cord injury (grade A). The association of a mechanical method and heparin is recommended (grade B). The duration of prophylaxis is 3 months in patients with a motor deficit (grade C). No prophylaxis is recommended after discectomy or limited laminectomy in patients without additional risk factors. Mechanical methods are recommended after spinal fusion or extended laminectomy. For patients with additional risk factors a low molecular weight heparin is recommended.

[Prevention of venous perioperative thromboembolism in ENT and maxillofacial surgery]. / Prévention de la maladie thromboembolique veineuse périopératoire en chirurgie ORL et maxillofaciale.

There are few studies of poor methodological quality on the risk of thromboembolism in head and neck surgery. The incidence of symptomatic deep vein thrombosis is estimated between, 0.1% and 0.6%. The patient's risk factors (cancer, alcoholism, smoking, malnutrition) determine for the assessment of the potential benefit of thromboembolism prophylaxis. No method can be recommended based on the literature. In patients receiving anticoagulant therapy undergoing superficial head and neck surgery or dental extraction, the literature suggest to continue anticoagulation throughout the perioperative period.

Which pelvic ring fractures are potentially lethal?

PURPOSE: Global mortality of polytraumatised patients presenting pelvic ring fractures remains high (330%), despite improvements in treatment algorithms in Level I Trauma Centers. Many classifications have been developed in order to identify and analyse these pelvic ring lesions. However, it remains difficult to predict intra-pelvic haemorrhage. The aim of this study was to identify pelvic ring anatomical lesions associated with significant blood loss, susceptible to lead to life-threatening haemorrhage. MATERIAL AND METHOD: This study focused on a retrospective analysis of patients' medical files, all of whom were admitted to one of the shock rooms of Grenoble University Hospital, France, between January 2004 and December 2008. Treatment was given according to the institutional algorithm of the Alps Trauma Center and Emergency North Alpine Network Trauma System (TRENAU). Different hemodynamical parameters at arrival were measured, and the fractures were classified according to Young and Burgess, Tile, Letournel and Denis. One hundred and ninety seven patients were analysed. They were subdivided into two groups, embolised (Group E) and non-embolised (Group NE). RESULTS: Group NE included 171 patients with a mean age of 40.2 ± 8.7 years (15-90). Group E included 26 patients with a mean age of 41.6 ± 5.3 years (18-67). Twenty-six patients died during the initial treatment phase. Eleven belonged to Group E and 15 to Group NE. Mortality was significantly higher in Group E (42.3% vs 8.8% in Group NE) (p < 0.05). There were significantly many more Tile C unstable fractures in Group E (p = 0.0014), and anterior lesions, according to Letournel, with pubic symphysis disruption were significantly more likely to lead to active bleeding treated by selective embolisation (p = 0.0014). Posterior pelvic ring lesions with iliac wing fracture and transforaminal sacral fractures (Denis 2) were also more frequently associated with bleeding treated by embolisation (p = 0.0088 and p = 0.0369 respectively). DISCUSSION/CONCLUSION: It appears that in our series the primary identification and classification of osteo-ligamentous lesions (according to Letournel and Denis' classifications) allows to anticipate the importance of bleeding and to adapt the management of patients accordingly, in order to quickly organise angiography with embolisation.

Prone position affects stroke volume variation performance in predicting fluid responsiveness in neurosurgical patients.

BACKGROUND: Stroke volume variation (SVV) during mechanical ventilation predicts preload responsiveness. We hypothesized that the prone position would alter the performance of this dynamic indicator. METHODS: Two parallel groups of ventilated neurosurgical patients with low tidal volume (6-8 ml.kg-1) were studied before surgical incision. SVV was measured at T0, T15 and T30 min during a fluid volume expansion (250 mL hetastarch 6% over 30 min) with patients in either the supine (N.=29; Supine group) or prone position (N.=23; Prone group). Fluid responsiveness was defined as an increase in the stroke volume index (SVI) of ≥20% at T30. Receiver-operating characteristics (ROC) curves were generated for SVV. RESULTS: Prone positioning significantly increased SVV. Volume expansion in the Prone group increased SVI but led to a decline in SVV from 16% (12-22; median, 25-75th percentile) at T0 to 9% (8-13%) at T30. These effects on SVI and SVV were more pronounced compared to those obtained in the Supine group (P ≤0.05). Fluid responsiveness was predicted by SVV >12% at T0 (sensitivity 88%, specificity 62%) in the Supine group. In the Prone group, the area under the ROC curve of SVV (0.53; 95% confidence interval 0.27-0.79) did not allow the determination of a threshold SVV value. CONCLUSION: In ventilated patients with low tidal volume, a prone position may have a direct effect on the heart that alters the performance of SVV in predicting fluid responsiveness. External factor such as prone position renders difficult the interpretation of SVV as a dynamic indicator of cardiac preload.

Lactate accumulation during moderate hypoxic hypoxia in neocortical rat brain.

Neocortical metabolism was studied during moderate hypoxic hypoxia, reoxygenation, and postmortem periods in anesthetized normocapnic rats using 1H nuclear magnetic resonance (NMR) spectroscopic imaging. Rats were prepared with unilateral common carotid occlusion to determine the ipsilateral metabolic effects of inadequate cerebral blood flow (CBF) response to hypoxia. No difference in brain metabolism between the two hemispheres was found during the control period. Hypoxic hypoxia (PaO2 = 54.1 +/- 5.8 mm Hg) resulted in a significant rise in neocortical lactate peak in both hemispheres, with an additional marked rise in the clamped side compared to the unclamped side (53 +/- 27 vs. 22 +/- 13% of postmortem value, p < 0.001). These lactate changes were not reversible within 30 min of reoxygenation in the clamped hemisphere. No changes in neocortical lactate peak were observed while elevating arterial lactate via intravenous lactate infusion without hypoxia. In addition, hypoxic hypoxia resulted in an apparent decrease in neocortical water and N-acetyl aspartate (NAA) signals, which were related to a shortening in T2 relaxation times. It is concluded that neocortical lactate is an early metabolic indicator during moderate hypoxic hypoxia in normocapnic conditions.

Exertional heatstroke and muscle metabolism: an in vivo 31P-MRS study.

An impairment of muscle energy metabolism has been suggested as a predisposing factor for, as well as a consequence of exertional heatstroke (EHS). Thirteen young men were investigated 6 months after a well-documented EHS using 31Phosphorus Magnetic Resonance Spectroscopy (31P-MRS). The relative concentrations of ATP, phosphocreatine (PCr), inorganic phosphate (Pi), phosphomonoesters (PME), and the intracellular pH (pHi) were determined at rest, during a graded standardized exercise protocol (360 active plantar flexions) and during recovery. Also the leg tissue blood flow was determined by venous occlusion plethysmography during the MRS procedure. Sixteen age-matched healthy male volunteers served as control group. In resting muscle, there were no significant differences between the groups as regards pHi, Pi/PCr, and ATP/PCr+Pi+PME ratios. During steady state exercise conditions, effective power outputs were similar for both groups at each level of exercise: 20, 35, and 50% of maximal voluntary contraction (MVC) of the calf muscle. No significant differences were shown between the two groups in Pi/PCr, pHi, or changes of leg blood flow at each level of exercise. At 50% MVC, Pi/PCr was 0.48 +/- 0.08 vs 0.47 +/- 0.05 (P = 0.96), pHi was 6.94 +/- 0.03 vs 6.99 +/- 0.02, respectively (P = 0.13). Finally, the rate of PCr resynthesis during recovery was not significantly different between the two groups: t1/2 PCr = 0.58 +/- 0.07 vs 0.50 +/- 0.05 min, respectively (P = 0.35). Therefore, no evidence of an impairment of muscle energy metabolism was shown in the EHS group during a standardized submaximal exercise using 31P-MRS performed 6 months after an EHS.

Discrimination between cross-country and downhill skiers by pulmonary and local 31PNMR evaluations.

The purpose of the present study was to correlate data on calf muscle metabolism using 31P nuclear magnetic resonance spectroscopy with measurements of whole body maximal oxygen consumption and maximal power output, and to determine whether the combination of these data could be used to predict athletic ability. Experiments were performed in a 2.35 Tesla, 35 cm diameter electromagnet on the leg muscle of sedentary human subjects (N = 6) and groups of athletes trained for endurance (cross-country skiers, N = 7) or strength performance (downhill skiers, N = 5). The exercise protocol consisted of successive plantar flexions performed at graded fractions of the maximal voluntary contraction (MVC). The results obtained from NMR investigation (changes in content of inorganic phosphate: Pi, phosphocreatine: PC and muscle ATP, and intracellular pH) were then compared with those of maximal O2 consumption (VO2max) and maximal power (MP). When the data on athletes were compared with those obtained on sedentary subjects, the curves illustrating the relationship between the imposed load and the Pi/PC ratio were significantly shifted toward high output power for a given Pi/PC value. It also appeared from this study that specific training in force development (downhill skiing) induced a slighter decrease in PC level than for endurance (cross-country skiers) despite improvement in physical performance. A slight but significant intracellular acidification was observed in the muscles of sedentary subjects and downhill skiers for contraction at, respectively, 50% and 80% of MVC, but not in the skeletal muscles of cross-country skiers.(ABSTRACT TRUNCATED AT 250 WORDS)

[Abnormalities of the skeletal muscle in hypertrophic cardiomyopathy. Spectroscopy using phosphorus-31 nuclear magnetic resonance]. / Anomalies du muscle squelettique dans la myocardiopathie hypertrophique. Une étude par spectroscopie RMN-31P.

There have been several reports of electromyographic and histological changes of striated skeletal muscle, especially of the type I oxidative fibres, in hypertrophic cardiomyopathy. In order to determine whether these anomalies also cause metabolic changes, a P-31 magnetic resonance spectroscopic study was undertaken at rest and on exercise in 5 pauci-symptomatic patients and 10 control subjects. The 5 patients had primary hypertrophic cardiomyopathy without alteration of systolic function or signs of congestive cardiac failure (Stages I or II). There were no clinical signs of myopathy. None of the patients were receiving betablocker therapy at the time of investigation. No significant difference was observed at rest. Intracellular acidosis was particularly pronounced in 2 of the 5 patients at the peak of exercise. In addition, the phosphocreatine recovery time (T1/2) was longer in the patient group (3.4 +/- 1.7 vs 1.6 +/- 0.9 mn; p less than 0.01) suggesting a mitochondrial metabolic oxidation abnormality. These results suggest that some patients with primary hypertrophic cardiomyopathy have abnormalities of mitochondrial oxidation in their striated skeletal muscle which can be demonstrated by P-31 magnetic resonance spectroscopy. This would suggest a global abnormality of striated muscle which, at a more advanced stage of the disease, could account for decreased effort tolerance in these patients.

[Difficult tracheal intubation in paediatric: myth or reality?]. / L'intubation difficile chez l'enfant : mythe ou réalité ?

Difficult tracheal intubation is a rare event according to the airway feature in child. This situation is mostly predictable, occurring in identified malformations and in specific diseases. Pre-operative clinical evaluation must detect facial abnormalities (lip or palate cleft, microtia, facial asymmetry.), micro or retrognathia, limited mouth opening, reduced distance between thyroid cartilage and chin, macroglossia and external ear malformations. According to this clinical evaluation, a strategy for managing difficult tracheal intubation is planned.