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Biomedical subjects

J F Payen

Publications and source records attributed to J F Payen.

At least 19 recordsLinked to original sources

[Delayed evaluation of continuous medical education].

OBJECTIVES: To analyse the results of delayed evaluation of European teaching sessions using a questionnaire provided by the French College of Anaesthesiologists. STUDY DESIGN: Open evaluation. MATERIAL: Questionnaires were completed 3-6 months after European courses provided in November-December 1999. METHOD: The types of professional exercise and the medical practice as well as the theme of the courses were pointed out. The evaluation included six items noted from 1 to 10: usefulness of the abstract book, discussion with colleagues, discussion with a manager, decision to modify medical practice, application of that decision, own objectives fulfilled. The global mean score for each item was calculated. Results were compared according to the professional mode of exercise and the theme of the course. RESULTS: 5/7 centres provided information. 91/239 questionnaires were returned to the organizers. The participants were working in different structures (private clinic: 25, university hospital: 31, general hospital: 27, PSPH: 8). The main exercise was anaesthesiology (75/77 answers). Means scores affected to the different items were around 7 for all but one of them. The mean score concerning discussion with a manager was significantly decreased to 3.5 +/- 3.2. Decision to modify their own practise was higher in private clinics compared to PSPH. The abstract book was more consulted after the first course (respiration and thorax). CONCLUSION: 3-6 months following the FEEA courses the participants thought to have fulfil their objectives and declared to have modify their medical practise. The lack of discussion with a manager should be analysed.

Anesthesiology↗

[Brain oedema following blood-brain barrier disruption: mechanisms and diagnosis].

Brain oedema following blood-brain barrier (BBB) disruption, or vasogenic oedema, is present in most cases of brain oedema. According to the Starling's law, water, ions and plasma proteins cross the BBB toward the interstitium if the driving forces for transmural bulk flow are excessive (mechanical origin) and/or if the BBB permeability is enhanced (chemical origin). Both mechanisms coexist in most cases. Excessive elevation of the gradient of hydrostatic pressure with lost of cerebral autoregulation has been proved in ischaemia/reperfusion and trauma, and suggested in acute mountain sickness and eclampsia. The BBB permeability can be enhanced by immediate (chemical mediators) or delayed (cellular infiltration) inflammatory response, or by alteration of the membrane integrity. This later can be transient (hyperosmolar BBB disruption), or permanent by activation of matrix metalloproteinase or by neovascularization with BBB breakdown. The reference method for the diagnosis of vasogenic oedema is the MRI diffusion-weighted imaging.

Blood-Brain Barrier↗

[Difficult tracheal intubation in paediatric: myth or reality?].

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.

Child↗

Brain electrical activity during combined hypoxemia and hypoperfusion in anesthetized rats.

In order to investigate the effects of moderate hypoxemia on brain electrical activity and the consequences of an altered cerebro-vascular response to hypoxemia, we recorded changes in electrical activity of the brain in anesthetized rats following unilateral carotid artery ligation (UCAL). In these animals, on the clamped side, cerebral blood flow, whilst normal during normoxia, shows less augmentation during hypoxemia. Six anesthetized (Halothane) Sprague-Dawley rats with UCAL were studied during 20 min periods of baseline (FI(O(2))=30%), hypoxemia (FI(O(2))=9.5%) and recovery (FI(O(2))=30%): mean arterial pressure of oxygen (PA(O(2))) achieved was 177.0, 37.6 and 160.1 mmHg, respectively. A significant decrease in the frequencies of the ECoG was observed bilaterally during hypoxemia: centroid frequency (fc)=3.37+/-0.14 and 2.85+/-0.13 Hz on the intact and clamped hemisphere respectively during hypoxemia versus fc=4.09+/-0.20 Hz (mean+/-S.E.M.) during baseline, which was not reversed during recovery (3.27+/-0.11 Hz) (ANOVA, P<0.01). The total power of the signal (Pw) was unaffected on the intact hemisphere but diminished on the clamped side during hypoxemia. Our results show that a significant slowing of ECoG is observed during hypoxemia of moderate intensity (40 mmHg) even when cerebro-vascular response to hypoxemia is preserved and that total power of the ECoG signal is severely diminished when the cerebro-vascular response to hypoxemia is impaired.

Animals↗

Regional response of cerebral blood volume to graded hypoxic hypoxia in rat brain.

BACKGROUND: The response of cerebral blood flow to hypoxic hypoxia is usually effected by dilation of cerebral arterioles. However, the resulting changes in cerebral blood volume (CBV) have received little attention. We have determined, using susceptibility contrast magnetic resonance imaging (MRI), changes in regional CBV induced by graded hypoxic hypoxia. METHODS: Six anaesthetized rats were subjected to incremental reduction in the fraction of inspired oxygen: 0.35, 0.25, 0.15, and 0.12. At each episode, CBV was determined in five regions of each hemisphere after injection of a contrast agent: superficial and deep neocortex, striatum, corpus callosum and cerebellum. A control group (n = 6 rats) was studied with the same protocol without contrast agent, to determine blood oxygenation level dependent (BOLD) contribution to the MRI changes. RESULTS: Each brain region exhibited a significant graded increase in CBV during the two hypoxic episodes: 10-27% of control values at 70% SaO2, and 26-38% at 55% SaO2. There was no difference between regions in their response to hypoxia. The mean CBV of all regions increased from 3.6 (SD 0.6) to 4.1 (0.6) ml (100 g)-1 and to 4.7 (0.7) ml (100 g)-1 during the two hypoxic episodes, respectively (Scheffé F-test; P < 0.01). Over this range, CBV was inversely proportional to SaO2 (r2 = 0.80). In the absence of the contrast agent, changes due to the BOLD effect were negligible. CONCLUSIONS: These findings imply that hypoxic hypoxia significantly raises CBV in different brain areas, in proportion to the severity of the insult. These results support the notion that the vasodilatory effect of hypoxia is deleterious in patients with reduced intracranial compliance.

Animals↗

Vessel size imaging.

Vessel size imaging is a new method that is based on simultaneous measurement of the changes Delta R(2) and Delta R(2)(*) in relaxation rate constants induced by the injection of an intravascular superparamagnetic contrast agent. Using the static dephasing approximation for Delta R(2)(*) estimation and the slow-diffusion approximation for Delta R(2) estimation, it is shown that the ratio Delta R(2)/Delta R(2)(*) can be expressed as a function of the susceptibility difference between vessels and brain tissue, the brain water diffusion coefficient, and a weighted mean of vessel sizes. Comparison of the results with 1) the Monte Carlo simulations used to quantify the relationship between tissue parameters and susceptibility contrast, 2) the experimental MRI data in the normal rat brain, and 3) the histologic data establishes the validity of this approach. This technique, which allows images of a weighted mean of the vessel size to be obtained, could be useful for in vivo studies of tumor vascularization. Magn Reson Med 45:397-408, 2001.

Animals↗

Assessing pain in critically ill sedated patients by using a behavioral pain scale.

OBJECTIVE: To establish the validity and reliability of a new behavioral pain scale (BPS) for critically ill sedated adult patients. DESIGN: Prospective evaluation. SETTING: Ten-bed trauma and surgical intensive care unit in a university teaching hospital. PATIENTS: Thirty mechanically ventilated patients who were receiving analgesia and sedation. INTERVENTION: Assessments with the BPS were completed consecutively at standardized times (morning, afternoon, night) by pairs of evaluators (nurse and nurse's aide). They collected physiologic parameters and BPS results before and during care procedures: non-nociceptive (group 1, compression stockings application and central venous catheter dressing change), nociceptive (group 2, endotracheal suctioning and mobilization), and retested nociceptive (group 3). The BPS score was the sum of three items that had a range score of 1-4: facial expression, movements of upper limbs, and compliance with mechanical ventilation. MEASUREMENTS AND MAIN RESULTS: Two hundred and sixty nine assessments were completed, including 104, 134, and 31 measurements in groups 1, 2 and 3, respectively. There was no difference in Ramsay scale scores between the three groups (Ramsay 4-6). Nociceptive stimulations (group 2) resulted in significantly higher BPS values than non-nociceptive ones (group 1, 4.9 vs. 3.5, p <.01), whereas the two groups had comparable BPS values before stimulation (3.1 vs. 3.0). A trend was found in group 2 between the dosage of sedation/analgesia and BPS: the higher the dosage, the lower BPS values and BPS changes to nociceptive stimulation. Group 3 had BPS values similar to group 2 at rest (3.2 vs. 3.2) and during the procedure (4.4 vs. 4.5), with good interrater correlations (r(2) =.71 and.50, respectively). CONCLUSIONS: These results indicate that the expression of pain can be scored validly and reliably by using the BPS in sedated, mechanically ventilated patients. Further studies are warranted regarding the utility of the BPS in making clinical decisions about the use of analgesic drugs in the intensive care unit.

Adult↗

Regional cerebral blood volume response to hypocapnia using susceptibility contrast MRI.

We used steady-state susceptibility contrast MRI to evaluate the regional cerebral blood volume (rCBV) response to hypocapnia in anesthetised rats. The rCBV was determined in the dorsoparietal neocortex, the corpus striatum, the cerebellum, as well as blood volume in extracerebral tissue (group 1). In addition, we used laser-Doppler flow (LDF) measurements in the left dorsoparietal neocortex (group 2), to correlate changes in CBV and in cerebral blood flow. Baseline values, expressed as a percentage of blood volume in each voxel, were higher in the brain regions than in extracerebral tissue. Hypocapnia (P(a)CO(2) approximately 25 mmHg) resulted in a significant decrease in CBV in the cerebellum (-17 +/- 9%), in the corpus striatum (-15 +/- 6%) and in the neocortex (-12 +/- 7%), compared to the normocapnic CBV values (group 1). These changes were in good agreement with the values obtained using alternative techniques. No significant changes in blood volume were found in extracerebral tissue. The CBV changes were reversed during the recovery period. In the left dorsoparietal neocortex, the reduction in LDF (group 2) induced by hypocapnia (-21 +/- 8%) was in accordance with the values predicted by the Poiseuille's law. We conclude that rCBV changes during CO(2) manipulation can be accurately measured by susceptibility contrast MRI. Abbreviations used: ANOVA analysis of variance CBF cerebral blood flow CBV cerebral blood volume CPMG Carr-Purcell-Meiboom-Gill FiO(2) fractional inspired oxygen ICP intracranial pressure LDF laser-Doppler flow MABP mean arterial blood pressure MRI magnetic resonance imaging MTT mean transit time PaCO(2) arterial partial pressure of carbon dioxide PaO(2) arterial partial pressure of oxygen PET positron emission tomography rCBV regional cerebral blood volume SPECT single-photon emission computed tomography

Analysis of Variance↗

[Prospective national survey on alternatives to obstetrical peridural analgesia].

OBJECTIVE: To assess the type of an alternative technique for epidural analgesia for pain relief during labour, the reason of its choice and its efficiency. STUDY DESIGN: A one-year prospective survey in 34 french hospitals. MATERIAL AND METHODS: A questionnaire was filled for each request for a non-epidural technique during labour. The data recorded the reason for this non-epidural method, the technique used, the repeated visual analog scale (VAS) pain scores before (T0) and during the treatment (T30, T60 T120,...), the maternal and foetal side effects of the method, and the maternal satisfaction. RESULTS: 177 questionnaires were studied among the 270 collected. The lack of VAS measurements was the main reason for excluding questionnaires. Refusing the epidural by the obstetric patient was the most frequent reason for requesting a non-epidural method (39%). Five non-epidural methods were identified: nalbuphine (NAL, n = 75), sufentanil by patient-controlled analgesia (SUF, n = 44), nitrous oxide/oxygen inhalation (N2O, n = 22), pethidine (PET, n = 19), and spinal analgesia (SA, n = 17). The choice of the method was dependant on the prescribe (midwife or anaesthetist) and of the cervical dilation. The SA group exhibited the most pain relief compared to the other groups during the treatment. No difference in pain relief was noted between the 4 groups (SUF, NAL, PET, N2O). Only in the PET group did the VAS pain score remain unchanged at T30. There were 25 maternal side effects, with a significant maternal sedation in the NAL group, and pruritus in the SA group. There were 6 respiratory depressions in infants, unrelated with the analgesic method. Maternal satisfaction was higher in the SA, SUF and N2O groups than in the PET and NAL groups. Factors explaining lack of analgesic effect (i.e. no decrease in VAS pain score more than 10 mm during the treatment) were the use of pethidine, the VAS pain score at T0 and the induced labour. CONCLUSION: Epidural and spinal analgesia are the most efficient methods for pain relief during labour. The analgesic effect of non-regional methods during labour is minimal, associated with some maternal side effects. Due to its lack of analgesic effect, pethidine should be avoided in this indication.

Adult↗

[Evaluating the quality of the anesthetic records].

OBJECTIVE: To assess the quality of the anaesthetic record for surgical and non surgical procedures and for elective and emergency surgery. STUDY DESIGN: Retrospective study in a university hospital. MATERIAL AND METHODS: Anaesthetic records collected over one month were analysed. The record included a referential with 38 items: nine for the identification of the patient and those who completed the record, 16 for the preoperative period and 13 for the operative period. Each item was qualified either as present (or correct), or absent, or unreadable or not applicable. RESULTS: Overall, 2,422 anaesthesia records were analysed, including 88,732 items. The mean level of correct items was 72%, and 1% of them were unreadable. Items for identification were significantly more correctly recorded (86%) than those concerning the preoperative (63%) and the operative (73%) periods (P < 0.01). Anaesthetic data for surgical procedures were significantly more correctly recorded (73%) than those for non-surgical procedures (63%) and surgery under local anaesthesia (52%; P < 0.01). Emergency surgical procedures were significantly less correctly recorded than elective ones (70 vs. 72%; P < 0.01). CONCLUSIONS: These results suggest that the quality of the anaesthetic records should be improved, mainly for the preoperative period and for non-surgical procedures.

Anesthesia↗

[Cellular energy metabolism: physiologic and pathologic aspects].

Cellular homeostasis requires permanent energy production and consumption. Adenosine triphosphate (ATP) is the major energy component for the cell. Its synthesis occurs mainly in mitochondria where the oxidative phosphorylations realise the coupling between oxygen consumption and phosphorylation of adenosine diphosphate. The anaerobic production of ATP plays an important role in the intermediary metabolism. The enzymatic complexes of the mitochondrial respiratory chain are energy transducers acting as proton pumps. In cardiomyocytes, the phosphocreatine circuit allows a substrate channelling between mitochondria and myofibrils. This metabolic compartmentation explains the difficulties of studying energetic metabolism in the beating heart and the lack of correlation between cardiac function and the usual energy parameters. Mitochondria are a potential site of action of anaesthetic agents. Lipophilic local anaesthetics impair cellular energy metabolism and mitochondrial ATP production. Such effects could be associated with toxic effects of these molecules. NMR or near-infrared spectroscopy are non invasive techniques for monitoring energetic metabolism in vivo. Clinical applications are developed for analysing brain, muscle or cardiac function in physiological and pathological conditions.

Adenosine Triphosphate↗

Changes in specific markers of haemostasis during reduction mammoplasty.

We have investigated the time course of the coagulation and fibrinolytic changes during moderate surgical trauma (elective reduction mammoplasty) in the absence of other confounding factors that could affect haemostasis. Specific markers for coagulation (prothrombin fragment 1.2 (F1.2), thrombin-antithrombin III complex (TAT)) and fibrinolysis (plasmin-antiplasmin complex (PAP) and D-dimer) were examined. Blood samples were obtained in 20 ASA I anaesthetized female patients at T0 (before operation), T75 (during operation) and T150 (before the end of operation). There was a progressive increase in blood loss during operation:mean 110 (SD 80) ml at T75 and 470 (180) ml at T150. This was associated with a significant increase in plasma concentrations of F1.2, PAP and D-dimer at T150 only (P < 0.05 vs T0). We conclude that moderate surgical trauma with blood losses greater than 300 ml can activate thrombin generation and fibrinolysis during operation.

Adult↗

Regional cerebral plasma volume response to carbon dioxide using magnetic resonance imaging.

BACKGROUND: Noninvasive techniques used to determine the changes in cerebral blood volume in response to carbon dioxide are hampered by their limited spatial or temporal resolution or both. Using steady state contrast-enhanced magnetic resonance imaging, the authors determined regional changes in cerebral plasma volume (CPV) induced by hypercapnia in halothane-anesthetized rats. METHODS: Cerebral plasma volume was determined during normocapnia, hypercapnia and recovery in the dorsoparietal neocortex and striatum of each hemisphere, in cerebellum, and in extracerebral tissue of rats with either intact carotid arteries (group 1) or unilateral common carotid ligation (group 2). Another group was studied without injection of a contrast agent (group 3). RESULTS: Hypercapnia (partial pressure of carbon dioxide in arterial blood [PaCO2] approximately 65 mmHg) resulted in a significant increase in CPV in the striatum (+42 +/- 8%), neocortex (+34 +/- 6%), and cerebellum (+49 +/- 12%) compared with normocapnic CPV values (group 1). Carotid ligation (group 2) led to a marked reduction of the CPV response to hypercapnia in the ipsilateral striatum (+23 +/- 14%) and neocortex (+27 +/- 17%) compared with the unclamped side (+34 +/- 15% and +38 +/- 16%, respectively). No significant changes in CPV were found in extracerebral tissue. In both groups, the CPV changes were reversed by the carbon dioxide washout period. Negligible changes in contrast imaging were detected during hypercapnia without administration of the contrast agent (group 3). CONCLUSIONS: The contrast-enhanced magnetic resonance imaging technique is sensitive to detect noninvasively regional CPV changes induced by hypercapnia in rat brain. This could be of clinical interest for determining the cerebrovascular reactivity among different brain regions.

Animals↗

Histological support for the difference between malignant hyperthermia susceptible (MHS), equivocal (MHE) and negative (MHN) muscle biopsies.

The aim of this study was to find, using modern techniques, any histological differences in muscle biopsies between malignant hyperthermia (MH) susceptible (MHS), MH equivocal (MHE) and MH negative (MHN) patients. On the basis of the European MH contracture test carried out in 83 patients, 23 were shown to be MHS, nine MHE and 51 MHN. Four lesions were found with a significantly high frequency in MHS and MHE biopsies: muscle fibre hypertrophy and atrophy, internal nuclei and myofibrillar necrosis. These four lesions were observed together in 35% of MHS but in none of the MHE or MHN biopsies. Three of these lesions occurred together in 57% of MHS, 33% of MHE and 4% of MHN biopsies. Our results support a histological difference between MHE, MHS and MHN biopsies and attempt to contribute towards a better definition of MHE status.

Adolescent↗

Effects of preoperative intentional hemodilution on the extravasation rate of albumin and fluid.

OBJECTIVE: To evaluate the effects of preoperative intentional hemodilution with 4% albumin solution on the extravasation rate of intravascular albumin and fluid in surgical patients. DESIGN: A prospective, randomized, clinical study. SETTING: University teaching hospital. PATIENTS: Two groups (control group [group 1] and hemodiluted group [group 2]) of 13 healthy patients were studied during a long-term (>4 hrs) surgical procedure. INTERVENTIONS: Autologous technetium-99m (99mTc)-labeled red blood cells and indium-oxine ((111)In)-labeled human serum albumin were injected intravenously during anesthesia at T = 0 min in the two groups for the determination of total blood volume and albumin diffusion space, respectively. In addition, body tetrapolar electrical impedance was used to assess extracellular fluid volume. In the hemodiluted group (group 2), 15 mL/kg of blood was withdrawn over 30 mins (T = 20 mins to T = 50 mins) and simultaneously replaced by an equal volume of 4% albumin solution (0.6 g/kg). MEASUREMENTS AND MAIN RESULTS: The albumin diffusion space, the colloid oncotic pressure, the plasma albumin concentration and the electrical impedance were measured before (T = 10 mins) and after (T = 60, 120, and 240 mins) hemodilution. Urine was collected from T = 10 mins to T = 240 mins. The total blood volume was calculated at T = 10 mins. No differences in the initial values were found between the two groups. In group 2, hemodilution (hematocrit 30 +/- 3%) resulted in a steeper increase in the albumin diffusion space (p < .05) and a progressive decrease in the body electrical impedance (p < .05). The extravasation rate of albumin was 0.052 +/- 0.007 mL/kg/min in group 2 vs. 0.038 +/- 0.020 mL/kg/min in group 1 (p < .05). The value of calculated plasma volume at T = 0 min did not shown any difference between the two groups. This value was then lower than expected in group 2, corresponding to a loss of plasma volume of >3 mL/kg. Urine output was significantly lower in group 2 than in group 1 (0.7 +/- 0.4 vs. 1.4 +/- 1.0 mL/min, respectively; p < .05). A comparable decrease in colloid oncotic pressure and in plasma albumin concentration was observed in both groups. CONCLUSIONS: These results suggest that preoperative hemodilution using 4% albumin on a 1:1 volume basis for blood substitution during a prolonged surgical procedure with reduced blood losses enhances the extravasation rate of albumin and fluid to the interstitial tissues, impeding the maintenance of isovolemia. These findings support the use of a volume of infused colloid solution higher than that of withdrawn blood during preoperative hemodilution.

Adolescent↗

[Skeletal muscle abnormalities in chronic obstructive lung disease with respiratory insufficiency. Value of P31 magnetic resonance spectroscopy].

31P magnetic resonance spectroscopy (31P MRS) is a non-invasive method to evaluate high energy compounds [adenosine triphosphate (ATP), phosphocreatin (PCr), inorganic phosphates (Pi)] and intracellular pH (pHi) of skeletal muscle during exercise and recovery. It is a clinically applicable method of investigation for severe COPD patients with respiratory failure since exercise is limited to a single group of muscle (calf). Pronounced alterations of muscular metabolism have been shown in these patients: (1) reduced aerobic capacity (as reflected by the ratio of Pi/PCr as a function of power and changes in recovery kinetics of PCr after exercise and (2) increased anaerobic metabolism (reflected by a decrease in intracellular pH). Four different studies reveal similar abnormalities. Acute oxygen administration partially improves these parameters, suggesting that other factors in addition to hypoxaemia may contribute to the metabolic impairment. The effect of increased physical activity on these abnormalities deserve further investigations.

Adenosine Triphosphate↗

[Prospective evaluation of a nuclear magnetic resonance score in the screening of malignant hyperthermia susceptibility. Initial results].

A prospective study for the noninvasive diagnosis of malignant hyperthermia (MH) susceptibility was conducted in 30 patients using 31P magnetic resonance spectroscopy (MRS). A score of MRS muscle abnormalities was determined before the in vitro contracture test. The patients were classified as MH susceptible or MH negative, according to an algorithm of MRS score values. Twenty-three patients were correctly classified using the MRS test, five had inclusive MRS score values and two patients were false-positive. There were no false-negative patients. These preliminary results suggest that the MRS test could be useful as a possible noninvasive diagnostic test in MH susceptibility.

Adolescent↗

In vitro 31P-magnetic resonance spectroscopy of muscle extracts in malignant hyperthermia-susceptible patients.

BACKGROUND: It was recently suggested that malignant hyperthermia-susceptible (MHS) patients could have an elevated peak of phosphodiesters in leg muscles using in vivo phosphorus magnetic resonance spectroscopy. In the current study, analysis of the phosphodiesters of muscle extracts of MHS and malignant hyperthermia-negative patients was performed using in vitro phosphorus magnetic resonance spectroscopy to chemically identify and to compare the muscle concentrations of water-soluble compounds between the two groups with respect to the muscle fiber type composition. METHODS: Perchloric acid extracts of the vastus medialis muscle of seven MHS patients and ten malignant hyperthermia-negative patients on the basis of the European malignant hyperthermia contracture test were subjected to in vitro phosphorus magnetic resonance spectroscopy carried out at 9.4 T. In addition, chemical identification of the phosphodiester region and histologic examination of the muscle specimens were performed. RESULTS: The peak in the phosphodiester region was assigned to glycerophosphorylcholine. Muscle perchloric acid extracts of MHS patients had a significantly (P < 0.05) higher glycerophosphorylcholine to the sum of phosphocreatine and inorganic phosphate (glycerophosphorylcholine/ [phosphocreatine +inorganic phosphate]) value than those of malignant hyperthermia-negative patients. Neither a difference in the fiber type composition between the two groups nor any specific myopathy were found. CONCLUSIONS: In the absence of histologic differences between muscle specimens of MHS and malignant hyperthermia-negative patients, these results could suggest that glycerophosphorylcholine could be a marker of an impairment in the phospholipid metabolism in the skeletal muscle of MHS patients.

Adolescent↗