251 resultados para Neuromuscular Blockade

em Université de Lausanne, Switzerland


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RÉSUMÉ Introduction L'effet des agents myorelaxants ainsi que des anticholinestérases sur la profondeur d'anesthésie a été étudié avec des résultats contradictoires. C'est pourquoi nous avons évalué l'effet de l'atracurium et de la néostigmine sur le BIS (bispectral index) ainsi que sur les potentiels auditives évoqués (middle-latency auditory evoked potentials, A-Line® autoregressive index [AAI]). Méthodes Après avoir obtenu l'accord du comité d'éthique local, nous avons étudié 40 patients ayant donné leur consentement écrit, ASA I-II, âgé de 18-69 ans. L'anesthésie générale a consisté en anesthésie intra-veineuse à objectif de concentration avec du propofol et du remifentanil. La fonction de la jonction neuromusculaire était monitorée en continu au moyen d'un électromyographe. Le BIS et l'AAI ont été enregistrés en continu. Après avoir atteint des valeurs stables au niveau du BIS, les patients ont été attribués à deux groupes par randomisation. Les patients du groupe 1 ont reçu 0.4 mg kg-1 d'atracurium et 5 minutes plus tard le même volume de NaCI 0.9%, dans le groupe 2 la séquence d'injection était inversée, le NaCI 0.9% en premier et l'atracurium en deuxième. Au moment où le premier « twitch » d'un train de quatre atteignait 10% de l'intensité avant la relaxation, les patients ont été randomisés une deuxième fois. Les patients du groupe N ont reçu 0.04 mg kg-1 de néostigmine et 0.01 rn9 kg-1 de glycopyrrolate alors que le groupe contrôle (G) ne recevait que 0.01 mg kg-] de glycopyrrolate. Résultats : L 'injection d'atracurium ou de NaCI 0.9% n'a pas eu d'effet sur le BIS ou l'AAI. Après l'injection de néostigmine avec glycopyrrolate, le BIS et I `AAI a augmenté de manière significative (changement maximal moyen du BIS 7.1 ± 7.5, P< 0.001, de l'AAI 9.7 ± 10.5, P< 0.001). Suite à l'injection de glycopyrrolate seule, le BIS et l'AAI a augmenté également (changement maximal moyen du BIS 2.2 ± 3.4, P< 0.008, de l'AAI 3.5 ± 5.7, P< 0.012), mais cette augmentation était significativement moins importante que dans le groupe N (P< 0.012 pour le BIS, P< 0.027 pour l'AAI). Conclusion Ces résultats laissent supposer que la néostigmine peut altérer la profondeur de l'anesthésie. La diminution de la profondeur d'anesthésie enregistrée par le BIS et l'AAI correspond probablement à une réapparition brusque d'une stimulation centrale liée à la proprioception. Au contraire, lors de la curarisation, le tonus musculaire diminue de manière beaucoup plus progressive, pouvant ainsi expliquer l'absence d'effet sur la profondeur d'anesthésie. ABSTRACT Background. Conflicting effects of neuromuscular blocking drugs and anticholinesterases on depth of anaesthesia have been reported. Therefore we evaluated the effect of atracurium and neostigmine on bispectral index (BIS) and middle-latency auditory evoked potentials (AAI). Methods. We studied 40 patients (ASA I-II) aged 18-69 yr. General anaesthesia consisted of propofol and remifentanil by target-controlled infusion and neuromuscular function was monitored by electromyography. When BIS reached stable values, patients were randomly assigned to one of two groups. Group I received atracurium 0.4 mg kg-1 and, 5 min later, the same volume of NaCl 0.9%; group 2 received saline first and then atracurium. When the first twitch of a train of four reached 10% of control intensity, patients were again randomized: one group (N) received neostigmine 0.04 mg kg-1 and glycopyrrolate 0.01 mg kg-1, and the control group (G) received only glycopyrrolate. Results. Injection of atracurium or NaCl 0.9% had no effect on BIS or AAI. After neostigmine¬glycopyrrolate, BIS and AAI increased significantly (mean maximal change of BIS 7.1 [SD 7.5], P<0.001; mean maximal change of AAI 9.7 [10.5], P<0.001). When glycopyrrolate was injected alone BIS and AAI also increased (mean maximal change of BIS 2.2 [3.4], P=0.008; mean maximal change of AAI 3.5 [5.7], P=0.012), but this increase was significantly less than in group N (P=0.012 for BIS; P=0.027 for AAI). Conclusion. These data suggest that neostigmine alters the state of propofol-remifentanil anaesthesia and may enhance recovery.

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OBJECTIVE: To provide an update to the original Surviving Sepsis Campaign clinical management guidelines, "Surviving Sepsis Campaign Guidelines for Management of Severe Sepsis and Septic Shock," published in 2004. DESIGN: Modified Delphi method with a consensus conference of 55 international experts, several subsequent meetings of subgroups and key individuals, teleconferences, and electronic-based discussion among subgroups and among the entire committee. This process was conducted independently of any industry funding. METHODS: We used the Grades of Recommendation, Assessment, Development and Evaluation (GRADE) system to guide assessment of quality of evidence from high (A) to very low (D) and to determine the strength of recommendations. A strong recommendation (1) indicates that an intervention's desirable effects clearly outweigh its undesirable effects (risk, burden, cost) or clearly do not. Weak recommendations (2) indicate that the tradeoff between desirable and undesirable effects is less clear. The grade of strong or weak is considered of greater clinical importance than a difference in letter level of quality of evidence. In areas without complete agreement, a formal process of resolution was developed and applied. Recommendations are grouped into those directly targeting severe sepsis, recommendations targeting general care of the critically ill patient that are considered high priority in severe sepsis, and pediatric considerations. RESULTS: Key recommendations, listed by category, include early goal-directed resuscitation of the septic patient during the first 6 hrs after recognition (1C); blood cultures before antibiotic therapy (1C); imaging studies performed promptly to confirm potential source of infection (1C); administration of broad-spectrum antibiotic therapy within 1 hr of diagnosis of septic shock (1B) and severe sepsis without septic shock (1D); reassessment of antibiotic therapy with microbiology and clinical data to narrow coverage, when appropriate (1C); a usual 7-10 days of antibiotic therapy guided by clinical response (1D); source control with attention to the balance of risks and benefits of the chosen method (1C); administration of either crystalloid or colloid fluid resuscitation (1B); fluid challenge to restore mean circulating filling pressure (1C); reduction in rate of fluid administration with rising filing pressures and no improvement in tissue perfusion (1D); vasopressor preference for norepinephrine or dopamine to maintain an initial target of mean arterial pressure > or = 65 mm Hg (1C); dobutamine inotropic therapy when cardiac output remains low despite fluid resuscitation and combined inotropic/vasopressor therapy (1C); stress-dose steroid therapy given only in septic shock after blood pressure is identified to be poorly responsive to fluid and vasopressor therapy (2C); recombinant activated protein C in patients with severe sepsis and clinical assessment of high risk for death (2B except 2C for postoperative patients). In the absence of tissue hypoperfusion, coronary artery disease, or acute hemorrhage, target a hemoglobin of 7-9 g/dL (1B); a low tidal volume (1B) and limitation of inspiratory plateau pressure strategy (1C) for acute lung injury (ALI)/acute respiratory distress syndrome (ARDS); application of at least a minimal amount of positive end-expiratory pressure in acute lung injury (1C); head of bed elevation in mechanically ventilated patients unless contraindicated (1B); avoiding routine use of pulmonary artery catheters in ALI/ARDS (1A); to decrease days of mechanical ventilation and ICU length of stay, a conservative fluid strategy for patients with established ALI/ARDS who are not in shock (1C); protocols for weaning and sedation/analgesia (1B); using either intermittent bolus sedation or continuous infusion sedation with daily interruptions or lightening (1B); avoidance of neuromuscular blockers, if at all possible (1B); institution of glycemic control (1B), targeting a blood glucose < 150 mg/dL after initial stabilization (2C); equivalency of continuous veno-veno hemofiltration or intermittent hemodialysis (2B); prophylaxis for deep vein thrombosis (1A); use of stress ulcer prophylaxis to prevent upper gastrointestinal bleeding using H2 blockers (1A) or proton pump inhibitors (1B); and consideration of limitation of support where appropriate (1D). Recommendations specific to pediatric severe sepsis include greater use of physical examination therapeutic end points (2C); dopamine as the first drug of choice for hypotension (2C); steroids only in children with suspected or proven adrenal insufficiency (2C); and a recommendation against the use of recombinant activated protein C in children (1B). CONCLUSIONS: There was strong agreement among a large cohort of international experts regarding many level 1 recommendations for the best current care of patients with severe sepsis. Evidenced-based recommendations regarding the acute management of sepsis and septic shock are the first step toward improved outcomes for this important group of critically ill patients.

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Background: In patients with cervical spine injury, a cervical collar may prevent cervical spine movements but renders tracheal intubation with a standard laryngoscope difficult if not impossible. We hypothesized that despite the presence of a semi-rigid cervical collar and with the patient's head taped to the trolley, we would be able to intubate all patients with the GlideScopeR and its dedicated stylet. Methods: 50 adult patients (ASA 1 or 2, BMI ≤35 kg/m2) scheduled for elective surgical procedures requiring tracheal intubation were included. After standardized induction of general anesthesia and neuromuscular blockade, the neck was immobilized with an appropriately sized semi-rigid Philadelphia Patriot® cervical collar, the head was taped to the trolley. Laryngoscopy was attempted using a Macintosh laryngoscope blade 4 and the modified Cormack Lehane grade was noted. Subsequently, laryngoscopy with the GlideScopeR was graded and followed by oro-tracheal intubation. Results: All patients were successfully intubated with the GlideScopeR and its dedicated stylet. The median intubation time was 50 sec [43; 61]. The modified Cormack Lehane grade was 3 or 4 at direct laryngoscopy. It was significantly reduced with the GlideScopeR (p <0.0001), reaching 2a in most of patients. Maximal mouth opening was significantly reduced with the cervical collar applied, 4.5 cm [4.5; 5.0] vs. 2.0 cm [1.8; 2.0] (p <0.0001). Conclusions: The GlideScope® allows oro-tracheal intubation in patients having their cervical spine immobilized by a semi-rigid collar and their head taped to the trolley. It furthermore decreases significantly the modified Cormack Lehane grade.

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We assessed the blockade of the renin-angiotensin system (RAS) achieved with 2 angiotensin (Ang) antagonists given either alone at different doses or with an ACE inhibitor. First, 20 normotensive subjects were randomly assigned to 100 mg OD losartan (LOS) or 80 mg OD telmisartan (TEL) for 1 week; during another week, the same doses of LOS and TEL were combined with 20 mg OD lisinopril. Then, 10 subjects were randomly assigned to 200 mg OD LOS and 160 mg OD TEL for 1 week and 100 mg BID LOS and 80 mg BID TEL during the second week. Blockade of the RAS was evaluated with the inhibition of the pressor effect of exogenous Ang I, an ex vivo receptor assay, and the changes in plasma Ang II. Trough blood pressure response to Ang I was blocked by 35+/-16% (mean+/-SD) with 100 mg OD LOS and by 36+/-13% with 80 mg OD TEL. When combined with lisinopril, blockade was 76+/-7% with LOS and 79+/-9% with TEL. With 200 mg OD LOS, trough blockade was 54+/-14%, but with 100 mg BID it increased to 77+/-8% (P<0.01). Telmisartan (160 mg OD and 80 mg BID) produced a comparable effect. Thus, at their maximal recommended doses, neither LOS nor TEL blocks the RAS for 24 hours; hence, the addition of an ACE inhibitor provides an additional blockade. A 24-hour blockade can be achieved with an angiotensin antagonist alone, provided higher doses or a BID regimen is used.

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BACKGROUND: In myasthenia gravis, antibody-mediated blockade of acetylcholine receptors at the neuromuscular junction abolishes the naturally occurring 'safety factor' of synaptic transmission. Acetylcholinesterase inhibitors provide temporary symptomatic treatment of muscle weakness but there is controversy about their long-term efficacy, dosage and side effects. This is the second update of a review published in The Cochrane Library Issue 2, 2011. OBJECTIVES: To evaluate the efficacy of acetylcholinesterase inhibitors in all forms of myasthenia gravis. SEARCH METHODS: On 8 July 2014 we searched the Cochrane Neuromuscular Disease Group Specialized Register, CENTRAL, MEDLINE and EMBASE for randomised controlled trials and quasi-randomised controlled trials regarding usage of acetylcholinesterase inhibitors in myasthenia gravis. Two authors scanned the articles for any study eligible for inclusion. We also contacted the authors and known experts in the field to identify additional published or unpublished data and searched clinical trials registries for ongoing trials. SELECTION CRITERIA: The types of studies were randomised or quasi-randomised trials. Participants were myasthenia gravis patients diagnosed by an internationally accepted definition. The intervention was treatment with any form of acetylcholinesterase inhibitor. Types of outcome measures Primary outcome measureImprovement in the presenting symptoms within one to 14 days of the start of treatment. Secondary outcome measures(1) Improvement in the presenting symptoms more than 14 days after the start of treatment.(2) Change in impairment measured by a recognised and preferably validated scale, such as the quantitative myasthenia gravis score, within one to 14 days and more than 14 days after the start of treatment.(3) Myasthenia Gravis Association of America post-intervention status more than 14 days after start of treatment.(4) Adverse events including muscarinic side effects. DATA COLLECTION AND ANALYSIS: One author (MMM) extracted the data, which were checked by a second author. We contacted study authors for extra information and collected data on adverse effects from the trials. MAIN RESULTS: We did not find any large randomised or quasi-randomised trials of acetylcholinesterase inhibitors in generalised myasthenia gravis either for the first version of this review or this update. One cross-over randomised trial using intranasal neostigmine in a total of 10 participants was only available as an abstract. It included three participants with ocular myasthenia gravis and seven with generalised myasthenia gravis. Symptoms of myasthenia gravis (measured as improvement in at least one muscle function) improved in nine of the 10 participants after the two-week neostigmine treatment phase. No participant improved after the placebo phase. Lack of detail in the report meant that the risk of bias was unclear. Adverse events were minor. AUTHORS' CONCLUSIONS: Except for one small and inconclusive trial of intranasal neostigmine, no other randomised controlled trials have been conducted on the use of acetylcholinesterase inhibitors in myasthenia gravis. The response to acetylcholinesterase inhibitors in observational studies is so clear that a randomised controlled trial depriving participants in a placebo arm of treatment would be difficult to justify.

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BACKGROUND: Depending on its magnitude, lower body negative pressure (LBNP) has been shown to induce a progressive activation of neurohormonal, renal tubular, and renal hemodynamic responses, thereby mimicking the renal responses observed in clinical conditions characterized by a low effective arterial volume such as congestive heart failure. Our objective was to evaluate the impact of angiotensin II receptor blockade with candesartan on the renal hemodynamic and urinary excretory responses to a progressive orthostatic stress in normal subjects. METHODS: Twenty healthy men were submitted to three levels of LBNP (0, -10, and -20 mbar or 0, -7.5, and -15 mm Hg) for 1 hour according to a crossover design with a minimum of 2 days between each level of LBNP. Ten subjects were randomly allocated to receive a placebo and ten others were treated with candesartan 16 mg orally for 10 days before and during the three levels of LBNP. Systemic and renal hemodynamics, renal sodium excretions, and the hormonal response were measured hourly before, during, and for 2 hours after LBNP. RESULTS: During placebo, LBNP induced no change in systemic and renal hemodynamics, but sodium excretion decreased dose dependently with higher levels of LBNP. At -20 mbar, cumulative 3-hour sodium balance was negative at -2.3 +/- 2.3 mmol (mean +/- SEM). With candesartan, mean blood pressure decreased (76 +/- 1 mm Hg vs. 83 +/- 3 mm Hg, candesartan vs. placebo, P < 0.05) and renal plasma flow increased (858 +/- 52 mL/min vs. 639 +/- 36 mL/min, candesartan vs. placebo, P < 0.05). Glomerular filtration rate (GFR) was not significantly higher with candesartan (127 +/- 7 mL/min in placebo vs. 144 +/- 12 mL/min in candesartan). No significant decrease in sodium and water excretion was found during LBNP in candesartan-treated subjects. At -20 mbar, the 3-hour cumulative sodium excretion was + 4.6 +/- 1.4 mmol in the candesartan group (P= 0.02 vs. placebo). CONCLUSION: Selective blockade of angiotensin II type 1 (AT1) receptors with candesartan increases renal blood flow and prevents the antinatriuresis during sustained lower body negative pressure despite a modest decrease in blood pressure. These results thus provide interesting insights into potential benefits of AT1 receptor blockade in sodium-retaining states such as congestive heart failure.

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Myotonic dystrophy Type 1 (DM-1) is caused by abnormal expansion of a (CTG) repeat located in the DM protein kinase gene. Respiratory problems have long been recognized to be a major feature of this disorder. Because respiratory failure can be associated with dysfunction of phrenic nerves and diaphragm muscle, we examined the diaphragm and respiratory neural network in transgenic mice carrying the human genomic DM-1 region with expanded repeats of more than 300 CTG, a valid model of the human disease. Morphologic and morphometric analyses revealed distal denervation of diaphragm neuromuscular junctions in DM-1 transgenic mice indicated by a decrease in the size and shape complexity of end-plates and a reduction in the concentration of acetyl choline receptors on the postsynaptic membrane. More importantly, there was a significant reduction in numbers of unmyelinated, but not of myelinated, fibers in DM-1 phrenic nerves; no morphologic alternations of the nerves or loss of neuronal cells were detected in medullary respiratory centers or cervical phrenic motor neurons. Because neuromuscular junctions are involved in action potential transmission and the afferent phrenic unmyelinated fibers control the inspiratory activity, our results suggest that the respiratory impairment associated with DM-1 may be partially due to pathologic alterations in neuromuscular junctions and phrenic nerves.

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We have recently reported that the PD-1 and CTLA4 signaling pathways are active in both effector and regulatory T cells, causing profound immune dysfunctions in the tumor microenvironment. In line with this notion, the dual blockade of PD-1- and CTLA4-conveyed signals may exert robust therapeutic effects. Here, we discuss the mechanisms possibly underlying such a synergic interaction.

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We investigated the physiological consequences of the most challenging mountain ultra-marathon (MUM) in the world: a 330-km trail run with 24000 m of positive and negative elevation change. Neuromuscular fatigue (NMF) was assessed before (Pre-), during (Mid-) and after (Post-) the MUM in experienced ultra-marathon runners (n = 15; finish time  = 122.43 hours ±17.21 hours) and in Pre- and Post- in a control group with a similar level of sleep deprivation (n = 8). Blood markers of muscle inflammation and damage were analyzed at Pre- and Post-. Mean ± SD maximal voluntary contraction force declined significantly at Mid- (-13±17% and -10±16%, P<0.05 for knee extensor, KE, and plantar flexor muscles, PF, respectively), and further decreased at Post- (-24±13% and -26±19%, P<0.01) with alteration of the central activation ratio (-24±24% and -28±34% between Pre- and Post-, P<0.05) in runners whereas these parameters did not change in the control group. Peripheral NMF markers such as 100 Hz doublet (KE: -18±18% and PF: -20±15%, P<0.01) and peak twitch (KE: -33±12%, P<0.001 and PF: -19±14%, P<0.01) were also altered in runners but not in controls. Post-MUM blood concentrations of creatine kinase (3719±3045 Ul·(1)), lactate dehydrogenase (1145±511 UI·L(-1)), C-Reactive Protein (13.1±7.5 mg·L(-1)) and myoglobin (449.3±338.2 µg·L(-1)) were higher (P<0.001) than at Pre- in runners but not in controls. Our findings revealed less neuromuscular fatigue, muscle damage and inflammation than in shorter MUMs. In conclusion, paradoxically, such extreme exercise seems to induce a relative muscle preservation process due likely to a protective anticipatory pacing strategy during the first half of MUM and sleep deprivation in the second half.

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Antagonism of renin-angiotensin-aldosterone system is exerted through angiotensin-converting enzyme inhibitors, angiotensin receptor antagonists, renin inhibitors and mineralocorticoid receptor antagonists. These drugs have been successfully tested in numerous trials and in different clinical settings. The original indications of renin-angiotensin-aldosterone system blockers have progressively expanded from the advanced stages to the earlier stages of cardiorenal continuum. To optimize the degree of blockade of renin-angiotensin-aldosterone system, dose uptitrations of angiotensin-converting enzyme inhibitors and angiotensin receptor antagonists or the use of a dual blockade, initially identified with the combination of angiotensin-converting enzyme inhibitors and angiotensin receptor antagonists, have been proposed. The data from the Ongoing Telmisartan Alone and in Combination with Ramipril Global Endpoint Trial (ONTARGET) study do not support this specific dual blockade approach. However, the dual blockade of angiotensin-converting enzyme inhibitors/angiotensin receptor antagonists with direct renin inhibitors is currently under investigation while that based on an aldosterone blocker with any of the previous three drugs requires more evidence beyond heart failure. In this review, we revisited potential advantages of dual blockade of renin-angiotensin-aldosterone system in arterial hypertension and diabetes.

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The acute blood pressure response to an angiotensin converting enzyme inhibitor (enalaprilat) was compared in patients with uncomplicated essential hypertension with that obtained under similar conditions with a calcium entry blocker (nifedipine). The patients were studied after a 3 week washout period. At a 48 h interval, each patient received in randomized order either enalaprilat (5 mg i.v.) or nifedipine (10 mg p.o.). Enalaprilat and nifedipine were equally effective in acutely lowering blood pressure. However, good responders to one agent were not necessarily good responders to the other.

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OBJECTIVES: We have reported previously that 80 mg valsartan and 50 mg losartan provide less receptor blockade than 150 mg irbesartan in normotensive subjects. In this study we investigated the importance of drug dosing in mediating these differences by comparing the AT(1)-receptor blockade induced by 3 doses of valsartan with that obtained with 3 other antagonists at given doses. METHODS: Valsartan (80, 160, and 320 mg), 50 mg losartan, 150 mg irbesartan, and 8 mg candesartan were administered to 24 healthy subjects in a randomized, open-label, 3-period crossover study. All doses were given once daily for 8 days. The angiotensin II receptor blockade was assessed with two techniques, the reactive rise in plasma renin activity and an in vitro radioreceptor binding assay that quantified the displacement of angiotensin II by the blocking agents. Measurements were obtained before and 4 and 24 hours after drug intake on days 1 and 8. RESULTS: At 4 and 24 hours, valsartan induced a dose-dependent "blockade" of AT(1) receptors. Compared with other antagonists, 80 mg valsartan and 50 mg losartan had a comparable profile. The 160-mg and 320-mg doses of valsartan blocked AT(1) receptors at 4 hours by 80%, which was similar to the effect of 150 mg irbesartan. At trough, however, the valsartan-induced blockade was slightly less than that obtained with irbesartan. With use of plasma renin activity as a marker of receptor blockade, on day 8, 160 mg valsartan was equivalent to 150 mg irbesartan and 8 mg candesartan. CONCLUSIONS: These results show that the differences in angiotensin II receptor blockade observed with the various AT(1) antagonists are explained mainly by differences in dosing. When 160-mg or 320-mg doses were investigated, the effects of valsartan hardly differed from those obtained with recommended doses of irbesartan and candesartan.

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Optimum management of non-acquired neuromuscular disorders requires a multidisciplinary approach in order to prevent secondary complications related to the progression of the disease and to maintain the patient's independency in daily activities. For treatments, the physiotherapists and occupational therapists must have precise and measurable goals to quantify muscle strength and functions in conjunction with a specialist in neurorehabilitation. Examples of simple motor scores or scales are given in order to transmit precise information to the GP and the multidisciplinary team, and type of orthosis and physiotherapy programmes are given as pieces of advice to assume the follow-up of patients.

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Recent data indicate that bradykinin participates in the regulation of neonatal glomerular function and also acts as a growth regulator during renal development. The aim of the present study was to investigate the involvement of bradykinin in the maturation of renal function. Bradykinin beta2-receptors of newborn rabbits were inhibited for 4 days by Hoe 140. The animals were treated with 300 microg/kg s.c. Hoe 140 (group Hoe, n = 8) or 0.9% NaCl (group control, n = 8) twice daily. Clearance studies were performed in anesthetized rabbits at the age of 8-9 days. Bradykinin receptor blockade did not impair kidney growth, as demonstrated by similar kidney weights in the two groups, nor did it influence blood pressure. Renal blood flow was higher, while renal vascular resistance and filtration fraction were lower in Hoe 140-treated rabbits. No difference in glomerular filtration rate was observed. The unexpectedly higher renal perfusion observed in group Hoe cannot be explained by the blockade of the known vasodilator and trophic effect of bradykinin. Our results indicate that in intact kallikrein-kinin system is necessary for the normal functional development of the kidney.