C14 A PROMISING SURGICAL TECHNIQUE IN PATIENTS WITH ATRIAL FUNCTIONAL MITRAL REGURGITATION: HYPER–DOWN–SIZING ANNULOPLASTY

Objective

Atrial functional mitral valve regurgitation is a less common form of functional mitral regurgitation with normal leaflet motion and morphology, preserved dimension and function of left ventricle, associated with atrial fibrillation ad/or left atrial dilatation. Several factors are involved into the etiology, such as mitral annular dilation and insufficient leaflet remodeling, atriogenic leaflet tethering, loss of annular saddle shape and contractility, changes in heart rate.

Methods

Eleven consecutive patients with atrial functional mitral regurgitation, mean age 65 ± 12 years, normal left ventricle dimension and ejection fraction greater than 50% underwent mitral valve repair via right mini–thoracotomy in case of isolated mitral and tricuspid valve surgery or via median sternotomy in case of combined procedures. Concomitant procedures include tricuspid valve repair in 1 patient and coronary artery bypass in 5 patients. All patients presented an increased dimension of left atrium (mean left atrial volume: 90 ± 23 ml); mitral annular dimension was investigated with trans–esophageal echocardiography before operation. In all patients was implanted a downsized complete rigid annuloplasty ring with asymmetrical design of two sizes smaller respect to measured intercommissural distance. Clinical outcomes of patients and echocardiographic findings related to mitral regurgitation recurrence and left ventricle function were followed in the time.

Results

At discharge, any patient present a residual mitral regurgitation greater than mild, mean trans–mitral gradient was 2.5 ±2.1 mmHg. During the follow–up period of 24 ± 5 months, the New York Heart Association functional class significantly improved from 2.5 ± 0.4 to 1.5 ± 2.1. In three patients occurred cardiac rhythm disturbances requiring hospital stay, only one patient developed a greater than mild mitral regurgitation, reoperation was not becessary in any case. Left atrial volume decreased from 90 ± 23 ml to 58 ± 30 ml.

Conclusions

Mitral annuloplasty with downsized ring is a safe and effective procedure in patient with atrial functional mitral regurgitation in the same way of patient with functional mitral regurgitation due to ventricular dilation and tethering. The comforting clinical and echocardiographic outcome in our small group of patient encourage future studies in this particular group of patients.

Awake pronation with helmet continuous positive airway pressure for COVID-19 acute respiratory distress syndrome patients outside the ICU: A case series

OBJECTIVE

Continuous positive airway pressure (CPAP) is an important therapeutic tool in COVID-19 acute respiratory distress syndrome (ARDS) since it improves oxygenation, reduces respiratory rate and can prevent intubation and intensive care unit (ICU) admission. CPAP during pronation has seldom been described and never during sedation.

DESIGN

Case series.

SETTING

High dependency unit of San Carlo University Hospital (Potenza, Italy).

PATIENTS

Eleven consecutive patients with COVID-19 ARDS.

INTERVENTION

Helmet CPAP in prone position after failing a CPAP trial in the supine position.

MAIN VARIABLE OF INTEREST

Data collection at baseline and then after 24, 48 and 72h of pronation. We measured PaO₂/FIO₂, pH, lactate, PaCO₂, SpO₂, respiratory rate and the status of the patients at 28-day follow up.

RESULTS

Patients were treated with helmet CPAP for a mean±SD of 7±2.7 days. Prone positioning was feasible in all patients, but in 7 of them dexmedetomidine improved comfort. PaO₂/FIO₂ improved from 107.5±20.8 before starting pronation to 244.4±106.2 after 72h (p<.001). We also observed a significantly increase in Sp0₂ from 90.6±2.3 to 96±3.1 (p<.001) and a decrease in respiratory rate from 27.6±4.3 to 20.1±4.7 (p=.004). No difference was observed in PaCO₂ or pH. At 28 days two patients died after ICU admission, one was discharged in the main ward after ICU admission and eight were discharged home after being successfully managed outside the ICU.

CONCLUSIONS

Helmet CPAP during pronation was feasible and safe in COVID-19 ARDS managed outside the ICU and sedation with dexmedetomidine safely improved comfort. We recorded an increase in PaO₂/FIO₂, SpO₂ and a reduction in respiratory rate.

Vacuum ultraviolet silicon photomultipliers applied to BaF2cross-luminescence detection for high-rate ultrafast timing applications

Inorganic scintillators are widely used for fast timing applications in high-energy physics (HEP) experiments, time-of-flight positron emission tomography and time tagging of soft and hard x-ray photons at advanced light sources. As the best coincidence time resolution (CTR) achievable is proportional to the square root of the scintillation decay time it is worth studying fast cross-luminescence, for example in BaF₂which has an intrinsic yield of about 1400 photons/MeV. However, emission bands in BaF₂are located in the deep-UV at 195 nm and 220 nm, which sets severe constraints on photodetector selection. Recent developments in dark matter and neutrinoless double beta decay searches have led to silicon photomultipliers (SiPMs) with photon detection efficiencies of 20%-25% at wavelengths of 200 nm. We tested state-of-the-art devices from Fondazione Bruno Kessler and measured a best CTR of 51 ± 5 ps full width at half maximum when coupling 2 mm × 2 mm × 3 mm BaF₂crystals excited by 511 keV electron-positron annihilation gammas. Using these vacuum ultraviolet SiPMs we recorded the scintillation kinetics of samples from Epic Crystal under 511 keV excitation, confirming a fast decay time of 855 ps with 12.2% relative light yield and 805 ns with 84.0% abundance, together with a smaller rise time of 4 ps beyond the resolution of our setup. The total intrinsic light yield was determined to be 8500 photons/MeV. We also revealed a faster component with 136 ps decay time and 3.7% light yield contribution, which is extremely interesting for the fastest timing applications. Timing characteristics and CTR results on BaF₂samples from different producers and with different dopants (yttrium, cadmium and lanthanum) are given, and clearly show that the the slow 800 ns emission can be effectively suppressed. Such results ultimately pave the way for high-rate ultrafast timing applications in medical diagnosis, range monitoring in proton or heavy ion therapy and HEP.

Early mandibular morphological differences in patients with FGFR2 and FGFR3-related syndromic craniosynostoses: A 3D comparative study

Syndromic craniosynostoses are defined by the premature fusion of one or more cranial and facial sutures, leading to skull vault deformation, and midfacial retrusion. More recently, mandibular shape modifications have been described in FGFR-related craniosynostoses, which represent almost 75% of the syndromic craniosynostoses. Here, further characterisation of the mandibular phenotype in FGFR-related craniosynostoses is provided in order to confirm mandibular shape modifications, as this could contribute to a better understanding of the involvement of the FGFR pathway in craniofacial development. The aim of our study was to analyse early mandibular morphology in a cohort of patients with FGFR2- (Crouzon and Apert) and FGFR3- (Muenke and Crouzonodermoskeletal) related syndromic craniosynostoses. We used a comparative geometric morphometric approach based on 3D imaging. Thirty-one anatomical landmarks and eleven curves with sliding semi-landmarks were defined to model the shape of the mandible. In total, 40 patients (12 with Crouzon, 12 with Apert, 12 with Muenke and 4 with Crouzonodermoskeletal syndromes) and 40 age and sex-matched controls were included (mean age: 13.7 months ±11.9). Mandibular shape differed significantly between controls and each patient group based on geometric morphometrics. Mandibular shape in FGFR2-craniosynostoses was characterized by open gonial angle, short ramus height, and high and prominent symphysis. Short ramus height appeared more pronounced in Apert than in Crouzon syndrome. Additionally, narrow inter-condylar and inter-gonial distances were observed in Crouzon syndrome. Mandibular shape in FGFR3-craniosynostoses was characterized by high and prominent symphysis and narrow inter-gonial distance. In addition, narrow condylar processes affected patients with Crouzonodermoskeletal syndrome. Statistical analysis of variance showed significant clustering of Apert and Crouzon, Crouzon and Muenke, and Apert and Muenke patients (p < 0.05). Our results confirm distinct mandibular shapes at early ages in FGFR2- (Crouzon and Apert syndromes) and FGFR3-related syndromic craniosynostoses (Muenke and Crouzonodermoskeletal syndromes) and reinforce the hypothesis of genotype-phenotype correspondence concerning mandibular morphology.

Awake pronation with helmet continuous positive airway pressure for COVID-19 acute respiratory distress syndrome patients outside the ICU: A case series

OBJECTIVE

Continuous positive airway pressure (CPAP) is an important therapeutic tool in COVID-19 acute respiratory distress syndrome (ARDS) since it improves oxygenation, reduces respiratory rate and can prevent intubation and intensive care unit (ICU) admission. CPAP during pronation has seldom been described and never during sedation.

DESIGN

Case series.

SETTING

High dependency unit of San Carlo University Hospital (Potenza, Italy).

PATIENTS

Eleven consecutive patients with COVID-19 ARDS.

INTERVENTION

Helmet CPAP in prone position after failing a CPAP trial in the supine position.

MAIN VARIABLE OF INTEREST

Data collection at baseline and then after 24, 48 and 72h of pronation. We measured PaO2/FIO2, pH, lactate, PaCO2, SpO2, respiratory rate and the status of the patients at 28-day follow up.

RESULTS

Patients were treated with helmet CPAP for a mean±SD of 7±2.7 days. Prone positioning was feasible in all patients, but in 7 of them dexmedetomidine improved comfort. PaO2/FIO2 improved from 107.5±20.8 before starting pronation to 244.4±106.2 after 72h (p<.001). We also observed a significantly increase in Sp02 from 90.6±2.3 to 96±3.1 (p<.001) and a decrease in respiratory rate from 27.6±4.3 to 20.1±4.7 (p=.004). No difference was observed in PaCO2 or pH. At 28 days two patients died after ICU admission, one was discharged in the main ward after ICU admission and eight were discharged home after being successfully managed outside the ICU.

CONCLUSIONS

Helmet CPAP during pronation was feasible and safe in COVID-19 ARDS managed outside the ICU and sedation with dexmedetomidine safely improved comfort. We recorded an increase in PaO2/FIO2, SpO2 and a reduction in respiratory rate.

Environmental and climatic risk factors for cystic and alveolar echinococcosis in Kyrgyzstan

Cystic and alveolar echinococcosis-CE and AE-are parasitic zoonoses caused by tapeworms Echinococcus granulosus and E. multilocularis. Their lifecycle is associated with particular environmental and climatic conditions, which have been identified as risk factors for CE and AE transmission. In this study, we assessed potential environmental and climatic risk factors for CE and AE in Kyrgyzstan where both diseases are endemic.

We previously estimated CE and AE surgical incidence and standardised incidence ratio (SIR) at the local community level in Kyrgyzstan for the period 2014-2016. We obtained 190 geospatial covariates on potential environmental and climatic risk factors for the two diseases from remotely sensed datasets. To account for the prolonged latency of CE and AE, we used covariates for different years (i.e. 2000, 2005 and 2010) and for an extended period of 30 years (i.e. monthly mean). We summarised the different covariates at the local community level and assessed correlations with the SIR of CE and AE using the Spearman's rank correlation test. We also computed the variance inflation factor (VIF) to assess multicollinearity between covariates. We then fitted three types of conditional autoregressive (CAR) models for each disease, namely an independent, a convolution, and a so-called Leroux model. We used covariates exhibiting significant correlation with the SIR of CE or AE and no multicollinearity as explanatory variables, and case counts as response variables. We selected the best CAR model and further refined the covariate selection using the Deviance Information Criterion (DIC).

Convolution models exhibited the best fit in terms of DIC for both diseases. None of the selected environmental variables exhibited significant effect on the number of CE cases, whilst there was a significative negative effect of mean annual temperature in 2005 on AE cases. These preliminary findings might inform targeted prevention and control in high-risk areas.

Key messages

We assessed environmental and climatic risk factors for cystic and alveolar echinococcosis in Kyrgyzstan. Our preliminary findings suggest that alveolar echinococcosis risk in Kyrgyzstan is associated with climatic factors such as 10-year lag mean annual temperature.

[Development and growth of the vault of the skull]

The vault of the skull is a region of the neurocranium formed by a process of membranous ossification. It consists of several bones: frontal bone, parietal bone, squamous part of the temporal bone, lamina ascendens of the sphenoid, and interparietal bone. The embryological origin of the bones of the skull vault is still the subject of controversy. This can be explained by the different animal models used for these purposes, but also by the various techniques applied to this problem. At all events, it seems that the cells of the neural crest generate some of the bones of the vault and that the others are derived from the mesoderm. This uncertainty should lead readers to be extremely cautious before using the presumptive maps published in the literature. Several tissues interact with osteo-progenitor cells: neural tube, surface ectoderm and dura mater. Analysis of genes in which mutations lead to abnormalities of the skull vault has partly revealed the molecular interactions. These are very complex and are the field of very numerous experimental investigations. In the relatively near future, we can hope to discover some of the molecular networks leading to the formation of these bony structures.

Correction to: Diffusion tensor imaging (DTI) and Tractography of the spinal cord in pediatric population with spinal lipomas: preliminary study

The article which was recently published contained error. The figures and figure captions were interchanged during the publication process of the paper.

A method to identify the areas at risk for the introduction of avian influenza virus into poultry flocks through direct contact with wild ducks

Wild dabbling ducks are the main reservoir for avian influenza (AI) viruses and pose an ongoing threat to commercial poultry flocks. Combining the (i) size of that population, (ii) their flight distances and (iii) their AI prevalence, the density of AI-infected dabbling ducks (DID) was calculated as a risk factor for the introduction of AI viruses into poultry holdings of Emilia-Romagna region, Northern Italy. Data on 747 poultry holdings and on 39 AI primary outbreaks notified in Emilia-Romagna between 2000 and 2017 were used to validate that risk factor. A multivariable Bayesian logistic regression was performed to assess whether DID could be associated with the occurrence of AI primary outbreaks. DID value, being an outdoor flock, hobby poultry trading, species reared, length of cycle and flock size were used as explanatory variables. Being an outdoor poultry flock was significantly associated with a higher risk of AI outbreak occurrence. The probability of DID to be a risk factor for AI virus introduction was estimated to be 90%. A DID cut-off of 0.23 was identified to define high-risk areas for AI virus introduction. Using this value, the high-risk area covers 43% of the region. Seventy-four per cent of the primary AI outbreaks have occurred in that area, containing 39% of the regional poultry holdings. Poultry holdings located in areas with a high DID value should be included in a risk-based surveillance programme aimed at AI early detection.

Subcutaneous blood patch for iatrogenic suboccipital pseudomeningocele following decompressive suboccipital craniectomy and enlarging duroplasty for the treatment of Chiari I malformation. Technical note

PURPOSE

Epidural blood patch (EBP) represents one of the best nonsurgical treatment for intracranial hypotension syndrome. Orthostatic headache caused by reduced intracranial cerebrospinal fluid (CSF) pressure, like in "spontaneous" intracranial hypotension or as consequence of lumbar puncture or anesthesiological procedure, can be managed with the injection of autologous blood on the epidural space with a successful rate of 89%, increased to 97% after a second application.

MATERIALS AND METHODS

This 9-year-old girl was admitted to our department because of a suboccipital pseudomeningocele. She was previously operated on for a Chiari type I malformation by suboccipital craniectomy, C1 laminectomy and duraplasty. At the admission, she complained for nucal pain. Brain MRI showed a large suboccipital fluid collection that persisted even after the revision of the duraplasty and the placement of an external lumbar drainage. The child underwent a first injection of a mixture of blood (10 ml) and fibrin glue (10 ml) within the subcutaneous space after needle-aspiration of the collection. The same treatment was repeated 3 weeks later.

RESULTS

The procedures were well tolerated and no local or systemic complications occurred. The fluid collection was significantly reduced after the first injection and it was completely effaced following the second one. Such a result remained stable after 3 months, as demonstrated by MRI. No recurrence of the pseudomeningocele was detected at the last clinical control (8-month follow-up).

CONCLUSION

Subcutaneous blood patch could represent a safe and effective option for the treatment of CSF fistula, especially in case of failure of the traditional management.

Mortality reduction in cardiac anesthesia and intensive care: results of the first International Consensus Conference

There is no consensus on which drugs/techniques/strategies can affect mortality in the perioperative period of cardiac surgery. With the aim of identifying these measures, and suggesting measures for prioritized future investigation we performed the first International Consensus Conference on this topic. The consensus was a continuous international internet-based process with a final meeting on 28 June 2010 in Milan at the Vita-Salute University. Participants included 340 cardiac anesthesiologists, cardiac surgeons, and cardiologists from 65 countries all over the world. A comprehensive literature review was performed to identify topics that subsequently generated position statements for discussion, voting, and ranking. Of the 17 major topics with a documented mortality effect, seven were subsequently excluded after further evaluation due to concerns about clinical applicability and/or study methodology. The following topics are documented as reducing mortality: administration of insulin, levosimendan, volatile anesthetics, statins, chronic β-blockade, early aspirin therapy, the use of pre-operative intra-aortic balloon counterpulsation, and referral to high-volume centers. The following are documented as increasing mortality: administration of aprotinin and aged red blood cell transfusion. These interventions were classified according to the level of evidence and effect on mortality and a position statement was generated. This International Consensus Conference has identified the non-surgical interventions that merit urgent study to achieve further reductions in mortality after cardiac surgery: insulin, intra-aortic balloon counterpulsation, levosimendan, volatile anesthetics, statins, chronic β-blockade, early aspirin therapy, and referral to high-volume centers. The use of aprotinin and aged red blood cells may result in increased mortality.

Mortality reduction in cardiac anesthesia and intensive care: results of the first International Consensus Conference

BACKGROUND

There is no consensus on which drugs/techniques/strategies can affect mortality in the perioperative period of cardiac surgery. With the aim of identifying these measures, and suggesting measures for prioritized future investigation we performed the first international consensus conference on this topic.

METHODS

The consensus was a continuous international internet-based process with a final meeting on June 28th 2010 in Milan at the Vita-Salute University. Participants included 340 cardiac anesthesiologists, cardiac surgeons and cardiologists from 65 countries all over the world. A comprehensive literature review was performed to identify topics that subsequently generated position statements for discussion, voting and ranking.

RESULTS

Of the 17 major topics with a documented mortality effect, seven were subsequently excluded after further evaluation due to concerns about clinical applicability and/or study methodology. The following topics are documented as reducing mortality: administration of insulin, levosimendan, volatile anesthetics, statins, chronic beta-blockade, early aspirin therapy, the use of preoperative intra-aortic balloon counterpulsation and referral to high-volume centers. The following are documented as increasing mortality: administration of aprotinin and aged red blood cell transfusion. These interventions were classified according to the level of evidence and effect on mortality and a position statement was generated.

CONCLUSION

This international consensus conference has identified the non-surgical interventions that merit urgent study to achieve further reductions in mortality after cardiac surgery: insulin, intra-aortic balloon counterpulsation, levosimendan, volatile anesthetics, statins, chronic beta-blockade, early aspirin therapy, and referral to high-volume centers. The use of aprotinin and aged red blood cells may result in increased mortality.

Mini-Invasive Surgery for Chiari Type I Malformation

Surgical treatment of Chiari I malformation and associated syringomyelia includes several different techniques with various degrees of invasiveness. Most extensive procedures may provide good long-term outcome in a good proportion of cases but are burdened by a quite high risk of postoperative complications. Thirty children operated on by simple bone decompression are retrospectively reviewed to assess the effectiveness of a less invasive technique. The present series comprises 30 children (18 females, 12 males; mean age: 68 months) treated from 1993 to 2005. All patients underwent foramen magnum decompression by means of suboccipital craniectomy and resection of the fibrous band at the level of foramen itself. Twenty-one children also required C1 laminectomy while a dural delamination was performed in 11 cases. The mean current follow-up is 4.3 years (1–12.6 years). Head and/or neck pain was the most frequent preoperative finding (56.7%), followed by upper and lower extremity weakness (20.0%), ataxia (20.0%) and vertigo (27.7%). Syringomyelia was present in 12 patients. A significant improvement of preoperative clinical symptoms and signs was observed in 28 patients (93.3%). Two children required adjunctive surgery. Neuroimaging revealed minor postoperative modifications in most cases regardless of tonsils location, while syringomyelia was reduced in size in 50% of the cases. Complication rate and length of hospital stay were significantly reduced compared with the literature data and our own experience using more invasive techniques. These data, compared with the literature, allow us to conclude that suboccipital craniectomy and Cl laminectomy (possibly integrated by dural delamination) is an effective and safe treatment for symptomatic children with Chiari I malformation and syringomyelia.

Endoscopic management of intra and paraventricular CSF cysts

BACKGROUND

The management of intra- and paraventricular lesions is one of the fields in which modern neuroendoscopic techniques have given the most significant contribution in terms of reduction in operative invasiveness and postoperative complications. In this context, fluid cysts represent an ideal ground on which results obtained with traditional surgical procedures (open surgery, shunting) have more and more to compare with the increasing number of encouraging results obtained by neuroendoscopy.

OBJECTIVE

The objective of this study was to retrospectively evaluate the results of the endoscopic treatment of intra- and paraventricular cysts performed at our institution and how they compare with what has been reported in the literature, concerning the results of open surgery, shunting, and endoscopic management.

MATERIALS AND METHODS

All the patients with intra- and paraventricular cerebrospinal fluid (CSF) cysts endoscopically managed at our institution between March 2000 and October 2006 were included. Based on cyst location documented by magnetic resonance imaging (MRI), the cohort of patients examined was subdivided in five groups: A, paraventricular cysts; B, choroids plexuses cysts; C, secondary intraventricular cysts in previously hydrocephalus shunted patients; D, quadrigeminal cistern arachnoid cysts; and E, suprasellar arachnoid cysts. The neuroendoscopic procedures were performed with a 30 degrees rigid endoscope (Storz Decq, 3.8 mm). The surgical plan and best trajectory were selected on preoperative MR imaging. Postoperatively, all patients underwent CT scans in the first 48 h after surgery and MR control 3 months after surgery.

RESULTS

There were 26 patients (18 M/8F). The mean age at diagnosis was 8.95 years. Five of 26 cases were adult patients. Four patients had paraventricular cysts; 2 patients had a choroids plexuses cyst; 6 patients a secondary intraventricular cyst in previously shunted hydrocephalus; 11 patients had a quadrigeminal cistern arachnoid cyst and 3 patients had a suprasellar arachnoid cyst. Fifteen patients had an associated hydrocephalus at the time of the surgical treatment (one patient in group A, six patients in group C, six in group D, and two in group E). Twenty-three out of 26 patients underwent endoscopic management of their cystic lesion as primary procedure; in the remaining three cases, it represented a secondary procedure after open cyst marsupialization or/and the implant of a cystoperitoneal shunt. Endoscopic management consisted in a cystoventriculostomy (CV) in 19 patients. Third ventriculostomy (ETV) was associated to CV in seven cases, and it was performed at the same time of the CV procedure in all these cases. There was no mortality, neither operative morbidity. At a mean follow-up of 2.15 years (0.1-4 years), a complete resolution of preoperative clinical symptoms and signs was recorded in 80.9% of symptomatic patients. Control MRI showed a reduced cyst size in 25/26 patients and a stable cyst size in the last case, with signs of CSF flow between the cyst and the cerebral ventricles in all cases. One out of 15 patients with associated hydrocephalus had a persistent ventriculomegaly without signs of increased intracranial pressure.

CONCLUSIONS

Our results confirm that endoscopic management of intra- and paraventricular cysts is a valid alternative to open surgery as well as to shunting procedures. Control of clinical symptoms and signs was obtained in around 80% of our patients, while radiological evidence of cyst size reduction occurred in more than 95% of them. These rates are comparable with results of open surgery and shunting. The main advantage of neuroendoscopy is the low incidence of complications, a result that is confirmed by the present series.

[Dialysis in the elderly]

Assuming >/= 75 years old as the age limit to define dialysis in the elderly, the incidence in this group of patients is progressively increasing in most dialysis units, with an annual growth of 8 to 16%, and represents 20 to 33% of the overall population being affected. The prevalence of the elderly dialysis group is also high, 14 to 20%, in the main literature casistics. Vascular nephropathies, 13 to 50%, represent the major cause of end-stage renal disease, followed by diabetes, 11 to 37%. First year survival rate is an acceptable 52 to 82%, whereas the fifth year value is on average 20 %, also due to the high baseline mortality in these patients. The death causes are mainly cardiac related and represent 45% of the overall mortality. The main prognostic factors are frequency and severity of comorbid factors, in addition to nutritional indexes that are particularly important in this age group. Dialysis dose and treatment time are not related to mortality. Haemodialysis and peritoneal dialysis complement each other to allow the best results. The survival rate, however, is usually better with haemodialysis, especially in old diabetic patients and after some years of treatment. Vascular access, intradialytic hypotension, cardiopathy, intestinal bleeding and amyloidotic arthropathy represent the more critical aspects of dialysis in the elderly, while the quality of life is sometimes unexpectedly good.

Monopharmacologic general anaesthesia with sevoflurane in paediatric patient with Prader-Willi syndrome

Prader-Willi syndrome (PWS) is a genetic disease caused by a loss of paternal genes located in chromosome 15. Children affected by this syndrome often have preterm delivery; during childhood the hallmarks are: severe infantile hypotonia and feeding problems. Afterward, neurologic manifestations, endocrine signs and dysmetabolic abnormalities are usually seen together with craniofacial manifestations and musculoskeletal abnormalities. Obesity causes sleep abnormalities including sleep apnea. The case we present is of a 5 year old child (CA) scheduled for strabismus surgery. The child has a lot of typical (PWS) signs. A number of anaesthesiologic problems are associated with (PWS). Some of them relate to obesity, others to facial dysmorphism. Moreover, the syndrome may give a prolonged and exaggerated response to every sedative drug. P.W.S. is also characterized by thermoregulatory disorders. Sleep apnea occurs often. Considering all these problems, we planned a monopharmacologic anaesthesiologic procedure using sevoflurane.

Peritoneal dialysis compared with hemodialysis in the treatment of end-stage renal disease

Whether to use peritoneal dialysis (PD) or hemodialysis (HD) is a major decision in terms of clinical outcome and management implications; the final choice is difficult because of the conflicting results of comparisons reported in the literature. A review of studies comparing survival shows either superiority of HD, or superiority of PD, or equivalence of the two techniques, but an analysis of the comparisons as a whole brings to light two clear phases in the survival curves. In the first, residual renal function (RRF) gives PD an advantage, or at least puts it on the same level as HD. In the second phase, the reduction in Kt/V as RRF declines gives PD a potential risk. After a few years of PD treatment a sharp watch is therefore necessary to detect signs of under-dialysis promptly and to shift the patient to HD. In patients without RRF it is more difficult to control hypertension with PD and they are more prone to hyperhydration. Despite a widespread belief in the Eighties that PD was the treatment modality of election for diabetics, HD is in fact preferable in these patients, except younger ones. High-turnover and low-turnover bone lesions are more frequent respectively in HD and PD patients. Anemia is better controlled with PD. Blood lipids and nutritional indices are less well controlled with PD. Despite poor technical survival, the "pool" of patients treated with PD frequently reaches 20-30% because it is indicated as first treatment in a large proportion. PD preserves renal function better than HD and is useful while awaiting renal transplantation, with faster postoperative restoration of diuresis. The quality of life with PD as home treatment is usually better than with HD. In conclusion, dialytic centers should establish an integrated PD/HD programme as the two methods are not competitive but are different tools for the treatment and rehabilitation of uremic patients.

[Dialysis in the elderly. Indications for and efficacy of hemodialysis]

In Italy, as in all industrialized countries, life expectancy is raised during the past 100 years; this trend leads to important implications in medicine and among nephrologists. The increased number of end stage renal disease patients living beyond 65 years, who start dialysis, has modified the typical picture in dialysis centers. The causes of this phenomenon are different, including an increasing number of chronic diseases, typical of the "third age", like type II diabetes mellitus or vascular disease, creation of treatment facilities and success of prevention. Besides goods results obtained in elderly dialysis patients, mainly due to a better psychological reaction to the treatment and to an easy achievement of a high dialytic dose (Kt/V), there are some negative aspects, like the hemodynamic intolerance or the difficulties to make an ideal vascular access. However, these problems don't discourage the nephrologist but rather they must lead to achieve a personalized or alternative treatment. Even if the quality of life and rehabilitation are quite acceptable in many elderly patients, so to justify the wide acceptance criteria, many ethical and medical problems concern the most serious cases. Also in this condition, a wide acceptance criteria, followed by a possible withdrawal (time limited trial of treatment), can represent a reasonable solution.

[Emergency and temporary vascular access]

The vascular access in emergency represents a basic need for every nephrologist in order to realize an extracorporeal circuit necessary to perform hemodialysis and many other derived therapies. In the eighties a progressive abandonment of the external shunt was noted with a concomitant increase of vena cava catheterization simpler to perform, especially under echographic control, and made increasingly possible by continuous technological improvements. The femoral access is utilized in about 30% of cases, especially in critically ill patients, due to easy performing procedures and few complications. Subclavian vein is abandoned as a first choice in favour of the jugular vein due to frequent and severe early complications and to thrombo-stenotic lesions observed in about 50% of catheterizations. Prevention and rapid treatment of the complications and careful management have an important role in obtaining a prolonged catheter survival. Even if, when possible, the classical arterio-venous fistula remains the ideal solution, at least in particular patient categories a jugular vein utilization as permanent access is justified.

[Effect of dialytic treatment and the relation between erythrocyte urea and plasma urea]

The existence of an intraerythrocytic binding between haemoglobin and urea is known; it determines, in normals, a higher erythrocyte than plasma urea concentration; this binding, in vitro, is progressive for an urea concentration range of 10-400 mg/dl. The only data found relating to dialysis patients, are reported by Nolph et al.; they indicate a decrease in the plasma-blood urea ratio during the blood transit through the dialyzer and a different ratio in comparison with normals, but in our opinion the method used to measure urea concentration was unsuitable. We determined urea distribution ratios by measuring, in blood and plasma, water and urea concentration in uremic inflow and outflow blood samples during dialysis. Our data indicate 1) an increase in outflow erythrocyte water (H2Oe inflow: 0.659, H2Oe outflow: 0.671 P less than 0.01) induced by a different erythrocyte osmotic gradient; 2) a not different ratio between urea of erythrocyte water and urea of plasma water in inflow and outflow samples of dialysed patients and in normals (respectively 1.06, 1.16, 1.13 p = n.s.). Our data from normal and uremic patients are like those found by Murdaugh & Doyle and by Colton & Lowrie in normals.

Renal tolerance of rubidium chloride: short-term clinical evaluation

The rubidium and lithium ions are known to have opposite effects on a wide range of biochemical and behavioral parameters in experimental animals. Based on the proven effectiveness of lithium as an antimanic agent, several trials have been conducted with rubidium in the acute treatment of the depressive phase of bipolar illness. The results to date are promising. However, the 30- to 60-day biologic half-life of rubidium has mandated careful studies of potential toxicity before engaging in long-term administration of this ion to depressive subjects. One area of potential concern is the possibility of renal toxicity, which could be expressed as unexpectedly increased retention of rubidium. The data in this paper show that after 15 days of rubidium administration, there are no changes beyond the normal range in a variety of kidney function tests, including in four enzymes which are specific markers of tubule cell function.