Life Cycle Assessment of a system for the extraction and transformation of Waste Water Treatment Sludge (WWTS)-derived lipids into biodiesel.

In recent years, the demand for biofuels has been growing exponentially, as has the interest in biodiesel produced from organic matrices. Particularly interesting, due to its economic and environmental advantages, is the use of the lipids present in sewage sludge as a raw material for the synthesis of biodiesel. The possible processes of this biodiesel synthesis, starting from lipid matter, are represented by the conventional process with sulfuric acid, by the process with aluminium chloride hexahydrate and by processes that use solid catalysts such as those consisting of mixed metal oxides, functionalized halloysites, mesoporous perovskite and functionalized silicas. In literature there are numerous Life Cycle Assessment (LCA) studies concerning biodiesel production systems, but not many studies consider processes that start from sewage sludge and that use solid catalysts. In addition, no LCA studies were reported on solid acid catalysts nor on those based on mixed metal oxides which present some precious advantages, over the homogeneous analogous ones, such as higher recyclability, prevention of foams and corrosion phenomena, and an easier separation and purification of biodiesel product. This research work reports the results of a comparative LCA study applied to a system that uses a solvent free pilot plant for the extraction and transformation of lipids from sewage sludge via seven different scenarios that differ in the type of catalyst used. The biodiesel synthesis scenario using aluminium chloride hexahydrate as catalyst has the best environmental profile. Biodiesel synthesis scenarios using solid catalysts are worse due to higher methanol consumption which requires higher electricity consumption. The worst scenario is the one using functionalized halloysites. Further future developments of the research require the passage from the pilot scale to the industrial scale in order to obtain environmental results to be used for a more reliable comparison with the literature data.

Analysis of voice in patients with untreated active acromegaly.

BACKGROUND: Voice changes are common clinical findings of acromegaly, although scanty data are available so far. OBJECTIVE: To analyze features and quantify changes of voice in patients with untreated active acromegaly. DESIGN AND METHODS: This was a pilot case-control study. Voice was analyzed using the Multi Dimensional Voice Program software, which generates 33 parameters related to fundamental frequency (F0), micro-perturbation of F0 and amplitude, noise, tremor, voice breaks and irregularities, and diplophony. PATIENTS: Thirteen consecutive patients (8 women, 5 men, mean age 48+/-9 yr) with active acromegaly, at first diagnosis, and 13 sex- and age-matched normal subjects (controls). RESULTS: Patients with untreated active acromegaly had mean values of parameters related to F0 significantly lower than those of controls, although mostly remaining in the normal range. Most acromegalic patients had micro-perturbation of F0, as indicated by higher mean of absolute or percentage jitter values than those of controls; micro-perturbation of amplitude was a common feature of voice in most acromegalic men. Noise-related parameters were also affected by acromegaly, being higher in male acromegalic patients than in controls and acromegalic women. On the contrary, parameters related to tremors, voice breaks, voice irregularities and diplophony did not differ in acromegalic patients and controls. CONCLUSIONS: Patients with untreated active acromegaly had low-pitched voice characterized by lowering F0 and increased values related to noise, micro perturbation of frequency, and amplitude.

Possible association between thyroid autoimmunity and Menière's disease.

Various aetiopathological mechanisms have been postulated to be at the root of Menière's disease (MD), and some data suggest that there may be also an underlying autoimmune factor. In fact, Menière patients manifest certain characteristics that are typical of autoimmune involvement association of particular human leucocyte antigen haplotypes, the presence of antibodies against internal ear antigens. In this study, we evaluated the association between thyroid autoimmunity and MD in a non-selected group of patients. We recruited 50 consecutive MD patients and two groups as controls: group A, 82 healthy volunteers; and group B, 50 subjects suffering from acute unilateral peripheral vestibulopathy. All subjects were submitted to instrumental assessment of cochlear-vestibular function and analysis of thyroid-stimulating hormone (TSH), free triiodothyronine, free thyroxine, anti-TSH receptor antibody (TR-Ab), anti-thyroperoxidase antibody (TPO-Ab) and anti-thyroglobulin antibody (Tg-Ab) in the blood. The prevalence of autoimmune thyroiditis in group B [6/50 (12%); 66.7% TPO-Ab and 33.3% Tg-Ab] was superimposable with the healthy controls [6/82 (7%); 66.7% TPO-Ab and 33.3% Tg-Ab]. In contrast, 38% of the MD patients (P = 0.0001 versus group A and group B) had significant autoantibody levels (68.4% TPO-Ab; 15.8% TPO-Ab + TR-Ab; 10.5% Tg-Ab; 5.2% TPO-Ab + Tg-Ab). Furthermore, 14% of the MD patients were hyperthyroid under l-thyroxine therapy, while no dysfunction was seen in the control groups. Overall, our data demonstrate a significant association between MD and thyroid autoimmunity, which suggests that an autoimmune factor is involved in the aetiopathogenesis of this disease. These findings suggest that it should be useful to submit MD patients to multi-disciplinary clinical investigation.

Fiberoptic endoscopic evaluation of swallowing (FEES): proposal for informed consent.

Fiberoptic endoscopic evaluation of swallowing (FEES) is now a first choice method for studying swallowing disorders on account of the various advantages it offers: easy to use, very well tolerated, allows bedside examination and is economic. Nevertheless, this diagnostic procedure is not without risks, the most probable consequences of which include discomfort, gagging and/or vomiting, vasovagal syncope, epistaxis, mucosal perforation, adverse reactions to topical anaesthetics and laryngospasm. The risks involved with FEES stress the importance of informing the patient of these; this is an important aspect in medicine that necessarily and immediately implies receiving the patient's so-called "informed consent". Informed consent should be obtained not only by means of specific printed forms but also after the patient has had an interview with the physician who will be performing the procedure and who will offer information according to the personal clinical, psychological, cultural and linguistic situation of the patient and in keeping with the type of procedure proposed. In the case of FEES, as with other invasive or non-invasive diagnostic procedures, therefore, routine written and signed consent, together with a patient/physician interview should fulfil what is known as "complete information". In this report, a specific form for informed consent to FEES procedures, is proposed.

Swallowing disorders: proposal of a method for forensic medicine assessment.

For a correct classification of dysphagia, morphologic instrumental investigations capable of analysing the anatomical structures of the digestive tract, are undoubtedly essential, but the most important investigations are the functional investigations, such as videofluoroscopy, fiberoptic endoscopic evaluation of swallowing, oro-pharyngo-oesophageal scintigraphy, manometry and pH-metry. Results of these examinations enable us to identify, in patients with dysphagia, the extent of permanent damage, as a consequence of injury to the structures designated to swallowing, must be such that it at least minimally impairs and decreases the relative function, but to a degree that can be detected and, in some manner, measured. From a legal point of view, alterations in swallowing, caused by damage to structures belonging to the respiratory-digestive tract, can be found in crimes against persons and particularly in those involving body injury. In the case of civil, but also in private or social insurance proceedings, it is necessary to distinguish which parameters are to be used as reference for evaluating and quantifying the injury in terms of reimbursement. With the introduction of complete biological well-being, injury is considered as an impairment of the worth and right to enjoy psychological-physical integrity as a quality of life. The criteria currently used internationally take into account the conception of psychological-physical efficiency; nevertheless, in Italian forensic medicine, there is no table that offers a thorough quantification of swallowing modifications, if one excludes oesophageal disorders. Herewith, an evaluation table, dividing oro-pharyngo-oesophageal dysphagia into five, progressively serious classes, is proposed.

Clinical applications of oro-pharyngo-oesophageal scintigraphy in the study of dysphagia.

The diagnostic approach to patients with dysphagia is well established and relies mainly on videofluoroscopy and endoscopy. Oro-pharyngo-oesophageal scintigraphy permits both a functional and a semi-quantitative study of the various stages of swallowing. Moreover, by means of this investigation, it is possible to estimate the amount of inhaled bolus. Oro-pharyngo-oesophageal scintigraphy with 99mTc-nanocolloid has been found to be easy to use, economical, well tolerated and, supplying precise indications regarding the extent of the swallowing disorder, then permits a better clinical definition of the patient. The limitations of swallowing scintigraphy are: poor definition in visualizing anatomic structures and low specificity when used as the only diagnostic test. Scintigraphy plays an important role in the diagnosis and follow-up of dysphagia, and its use, together with other diagnostic techniques, increases diagnostic accuracy. In this study, the role of oro-pharyngo-oesophageal scintigraphy has been analysed in patients with post-surgical, neurological and oesophageal dysphagia.

Paradoxical vocal cord dysfunction: clinical experience and personal considerations.

Paradoxical vocal cord dysfunction is a nosographic entity that remains to be fully elucidated as far as concerns criteria required for diagnosis and underlying aetiopathogenesis. The disorder manifests with repeated episodes of acute dyspnoea associated with a series of symptoms that may include hoarseness, globus, chest pain and "shortness of breath". A retrospective analysis of cases with acute dyspnoea referred to our Department between June 2004 and June 2005 revealed 3 patients with paradoxical vocal cord dysfunction. In 2 of these 3 cases, concomitant psychiatric morbidity was observed and the third also presented gastro-oesophageal reflux. In one patient, the episodes of dyspnoea were triggered by inspiration of irritating substances. Diagnosis of the condition requires a high level of suspicion, which is confirmed by a laryngoscopic investigation that demonstrates hyperadduction of the true vocal cords and a reduction of at least 50% in the breathing space. From a therapeutic point of view, patients with paradoxical vocal cord dysfunction require, in our opinion, a multidisciplinary approach; in fact, only a team comprising otorhinolaryngologists, phoniatricians, pulmonologists, neurologists, allergologists, psychotherapists and speech therapists is capable of defining the appropriate treatment according to the clinical and psychological characteristics of each individual patient. Our results with speech therapy, focused on respiratory and speech retraining, are reported.

Stabilometric findings in patients affected by organic dysphonia before and after phonomicrosurgery.

The purpose of this study is to understand if there is any alteration in the posture of patients affected by organic dysphonia and describe possible postural modifications after phonomicrosurgery on the vocal folds. Forty subjects (22 males, 18 females; mean age 32.6 ± 7.5 years) suffering from organic dysphonia (15 cases of polyps, 11 submucosal retention cysts, 10 bilateral fibrous vocal fold nodules and 4 bilateral Reinke's oedema) were examined by open-eye and closed-eye posturography while breathing spontaneously before surgery, 24 hours after surgery and after 6 months. The variables taken into account were: the coordinates of the centre of pressure on both frontal and sagittal planes, length and surface of the track, mean velocity of the oscillations and relative standard deviations, spectral analysis of oscillation frequency, statokinesigram and stabilogram values. No characteristic pathological pattern was seen in basal stabilometry in any of the subgroups (polyps, cysts, Reinke's oedema). Only the subgroup of patients with fibrous vocal fold nodules (8/10; 80%) showed a slight forward shift from the centre of gravity when analysed in both open-eye and closed-eye posturography. A comparison performed within the same subgroup using open-eye and closed-eye posturography before and after surgery revealed no significant difference in any of the parameters being studied. The use of static stabilometry in this study demonstrates the absence of characteristic postural alterations in patients affected by organic dysphonia and also excludes that simple removal of the vocal fold lesion can change posture.

Transtympanic steroids in refractory sudden hearing loss. Personal experience.

The treatment of choice for sudden sensorineural hearing loss is still lacking. Many drugs have been used over the years, with varying results and steroids have proven to be effective in clinical trials, albeit systemic administration is associated with untoward side-effects and cannot be used in all patients. The transtympanic approach presents two main advantages: first, it allows higher concentrations in the inner ear environment and, second, it minimizes systemic absorption. Aim of the present investigation was to establish the effectiveness of transtympanic steroid treatment for sudden sensorineural hearing loss in patients in whom conventional treatment had failed. For this purpose, a prospective, non-randomized study was designed to evaluate hearing improvement in sudden sensorineural hearing loss patients treated with transtympanic steroids. A solution of methyl-prednisolone and sodium bicarbonate was administered, via a transtympanic injection, in 10 patients. Hearing levels were evaluated before treatment and on days 1, 7 and 30, thereafter. Improvement in hearing was observed in 70% of patients, moreover, in patients not usually considered amenable to this kind of treatment. Transtympanic steroid treatment is an effective and safe option for patients with sudden sensorineural hearing loss when conventional treatment regimens have failed. Further studies are needed to define the optimal dosage, route of administration and type of steroids.

Comparison between videofluoroscopy, fiberoptic endoscopy and scintigraphy for diagnosis of oro-pharyngeal dysphagia.

The purpose of this study was to compare videofluoroscopy (VFS), fiberoptic endoscopic evaluation of swallowing (FEES) and oro-pharyngo- oesophageal scintigraphy (OPES) with regards to premature spillage, post-swallowing residue and aspiration to assess the reliability of these tests for detection of oro-pharyngeal dysphagia. Sixty patients affected with dysphagia of various origin were enrolled in the study and submitted to VFS, FEES and OPES using a liquid and semi-solid bolus. As a reference, we used VFS. Both the FEES and the OPES showed good sensitivity with high overall values (≥ 80% and ≥ 90% respectively). The comparison between FEES vs VFS concerning drop before swallowing showed good specificity (84.4% for semi-solids and 86.7% for liquids). In the case of post-swallowing residue, FEES vs VFS revealed good overall validity (75% for semi-solids) with specificity and sensitivity well balanced for the semi-solids. OPES vs. VFS demonstrated good sensitivity (88.6%) and overall validity (76.7%) for liquids. The analysis of FEES vs. VFS for aspiration showed that the overall validity was low (≤ 65%). On the other hand, OPES demonstrated appreciable overall validity (71.7%). VFS, FEES and OPES are capable of detecting oro-pharyngeal dysphagia. FEES gave significant results in the evaluation of post-swallowing residues.

How does radiotherapy impact swallowing function in nasopharynx and oropharynx cancer? Short-term results of a prospective study.

The objective of this study is to report the initial results of a prospective trial assessing instrumental deglutition function in nasopharynx and oropharynx cancers after radio or chemoradiotherapy using intensity-modulated radiotherapy (IMRT). IMRT was delivered aiming to spare the swallowing organ at risk (SWOARs) for Stage II-IV naso- and oropharynx cancer. Objective instrumental assessment included videofluoroscopy (VFS), fiberoptic endoscopic evaluation of swallowing (FEES) and oro-pharyngeal-oesophageal scintigraphy (OPES) at baseline and at 1 month after radiotherapy. Dysphagia parameter scores were calculated at each exam after liquid (L) and semi-liquid (SL) bolus intake: pre-deglutition penetration, aspiration, pharyngeal transit time (PTT) and hypopharyngeal retention index (HPRI). Overall, 20 patients (6 nasophaynx and 14 oropharynx) completed treatment and instrumental assessment after 1 month. Comparison between pre- and post-treatment HPRI score values showed a significant worsening in both FEES-L (p = 0.021) and SL (p = 0.02) and at VFS-L (p = 0.008) and SL (p = 0.005). Moreover, a relationship between HPRI worsening at FEES-L and FEES-SL (p = 0.005) as well as at VFS-L and VFS-SL (p < 0.001) was observed. PTT was not significantly affected by radiotherapy (p > 0.2). Only a few patients experienced pre-deglutition penetration (1 patient with base of tongue cancer at FEES-L and SL) and aspiration (1 patient with nasopharynx cancer at OPES-L and FEES-SL) after radiotherapy. Our early results showed that IMRT-SWOARs sparing caused a significant increase in the post-deglutition HPRI score. Longer follow-up will be necessary to evaluate if the increase of HPRI is related to a high risk of developing late aspiration.

Drop attacks and vertical vertigo after transtympanic gentamicin: diagnosis and management.

Drop attacks represent a significant problem during the natural course of Meniere's disease. They are characterized by a sudden fall to the ground without loss of consciousness. Diagnosis is clinical and based on the typical description of the patient. Involvement of vertical canal is possible during Meniere's disease and also after gentamicin application. Treatment of drop attacks is still a matter of discussion; most cases have a benign course with spontaneous remission and no treatment is necessary. In severe cases, aggressive treatment (surgical or pharmacological) is necessary. A case of drop attack associated with vertical vertigo is presented. Vestibular tests were performed in order to assess the involvement of inner ear. Caloric test and ice water test reveal no response. Vestibular Evoked Myogenic Potentials are present even after high doses of gentamicin. Drop attacks and vertical vertigo can occur after transtympanic gentamicin and can be well managed with high doses of local gentamicin.

A biorobotic model of the human larynx.

This work focuses on a physical model of the human larynx that replicates its main components and functions. The prototype reproduces the multilayer vocal folds and the ab/adduction movements. In particular, the vocal folds prototype is made with soft materials whose mechanical properties have been obtained to be similar to the natural tissue in terms of viscoelasticity. A computational model was used to study fluid-structure interaction between vocal folds and the airflow. This tool allowed us to make a comparison between theoretical and experimental results. Measurements were performed with this prototype in an experimental platform comprising a controlled air flow, pressure sensors and a high-speed camera for measuring vocal fold vibrations. Data included oscillation frequency at the onset pressure and glottal width. Results show that the combination between vocal fold geometry, mechanical properties and dimensions exhibits an oscillation frequency close to that of the human vocal fold. Moreover, computational results show a high correlation with the experimental one.

The value of oropharyngoesophageal scintigraphy in the management of aspiration into the tracheobronchial tree in neurological patients.

AIM: Dysphagia and bolus aspiration are two of the most frequent and invalidating symptoms of various neurological diseases. Swallowing disorders often lead to tracheobronchial aspiration with consequent pneumonia episodes. Aspiration pneumonia per se constitutes the most frequent cause of death in these patients, with mortality rate ranging from 20% to 62%. Oropharyngoesophageal scintigraphy (OPES) permits functional quantitative assessment of the different stages of swallowing, together with the detection and quantitative measurement of bolus aspiration. In this work, we analyzed the role of OPES in patients with different neurological conditions to evaluate swallowing and to detect and quantify bolus aspiration. MATERIAL AND METHODS: We enrolled 43 neurological patients (25 women and 18 men, mean age 67.3±12.4 yr) complaining of dysphagia with suspected inhalation. All patients underwent OPES with (99m)Tc-nanocolloid using a liquid bolus first, followed by a semi-solid bolus. We evaluated the following parameters: Oral, Pharyngeal and Esophageal Transit Time, Oro-Pharyngeal Retention Index, Esophageal Emptying Rate, and Aspiration Rate (% AR). RESULTS: OPES detected some airway aspiration in 26/43 patients. 19 patients had tracheal aspiration (with a mean 18.1% AR) and the remaining 7 patients had bilateral broncho-pulmonary aspiration (mean 44.9% AR). CONCLUSIONS: OPES is a feasible, repeatable and noninvasive method that allows quantitative assessment of bolus aspiration into the tracheobronchial tract, thus representing a useful and accurate tool to guide the most appropriate treatment and to monitor response to therapy in neurological patients with dysphagia.

Plasmodium vivax malaria after autologous bone marrow transplantation: an unusual complication.

We report the case of unusually early infection by Plasmodium vivax after autologous bone marrow transplantation in a 20-year-old female from Bangladesh affected by acute myelogenous leukemia in first complete remission (CR) who underwent autologous bone marrow transplantation in our center. During the aplastic phase she became febrile; broad spectrum antibiotics and antifungal therapy were without effect. Blood smears were examined and Plasmodium vivax was detected despite a very low number of red cells infected. Cloroquine therapy for 3 days was given followed by primaquine for 2 weeks in order to avoid possible cloroquine resistance. Fever disappeared within 48 h from initial treatment and the patient was discharged having completely recovered at day +30. Primary malaria infection in non-endemic areas is a very rare event. In this particular case, after excluding primary infection or blood transfusion-mediated infection, malaria was attributed to a recrudescence of a primary unidentified infection.

Hemostatic alterations in patients with acute, unilateral vestibular paresis.

OBJECTIVES: The etiopathogenesis of acute unilateral peripheral vestibulopathy (APV) still remains a matter of debate; ischemic changes in the circulation of the labyrinth may play a role. We consequently looked for possible hemostasis alterations in a group of patients with APV of an unknown nature. METHODS: We evaluated blood parameters known to be involved in circulation disorders, including total and HDL cholesterol, triglycerides, apolipoprotein A and B, lipoprotein(a), homocysteine, folate, prothrombin time, activated partial thromboplastin time, fibrinogen, D-dimer, antithrombin III, protein C, protein S, activated protein C resistance, and anticardiolipin IgG and IgM antibodies. A series of 23 patients affected with APV were consecutively referred to our department, in the acute phase, before treatment, and in the follow-up phase after 4 to 6 weeks of pharmacologic washout. The aforementioned blood parameters were also measured in a series of 15 patients with Menière's disease. RESULTS: The patients with APV in the acute phase compared with the patients with Menière's disease in the acute phase exhibited increased plasma levels of fibrinogen (mean, 338.3 +/- 135.9 SD vs 271.3 +/- 69.8 SD mg/dL, P = 0.05), increased plasma levels of D-dimer (mean, 320 +/- 207.8 SD vs 226.7 +/- 138.7 SD NG/mL), enhanced plasma levels of lipoprotein(a) (41.4 +/- 38.6 SD vs 16 +/- 18.2 SD mg/dL, F = 5.67, P = 0.02), high leukocyte count (9.1 +/- 2.7 SD vs 6.5 +/- 1.3 SD x 10(3)/microL; F = 8.42, P < 0.006), and low serum folate concentration (5.3 +/- 1.8 SD vs 7.1 +/- 2.7 NG/mg; F = 4.34, P = 0.04). During follow-up the prothrombin time was prolonged (F = 4.34, P = 0.04) and leukocyte count decreased (F = 7.39, P < 0.019) in the APV patients, whereas fibrinogen, D-dimer, lipoprotein(a), and folate were unchanged. CONCLUSION: Our results provide evidence suggesting an involvement of the hemostatic system in APV.

Bacterial and viral DNA in periodontal disease: a study using multiplex PCR.

Recent studies have suggested an association between periodontal disease and the presence of Herpesviruses, in particular: Epstein-Barr virus (EBV) and Human Cytomegalovirus (CMV) (Contreras et al., 1999--Contreras et al., 2000--Slots et al., 2000--Ting et al., 2000). In the work reported in this paper, we use a multiplex Polymerase Chain Reaction (PCR) to compare the presence of Herpesviruses and putative bacterial pathogens in patients with periodontal disease and in healthy individuals. Direct detection of microorganisms with PCR is shown to offer significant advantages in terms of time, effort and cost. The study detected no statistically significant differences between the prevalence of EBV and CMV in patients and controls. The failure to replicate previous findings may be due to differences in the age composition and the geographical and social origins of the study groups. The study detected a significant excess of HSV-1 in periodontal patients. This suggests that the role of Herpesviruses in the pathogenesis of periodontal disease deserves further investigation. The bacterial assay confirmed the results of previous studies showing a strong association between periodontitis and the presence of A. actinomycetemcomitans, P. gingivalis and P. intermedia.

Alternobaric oxygen therapy in long-term treatment of Ménière's disease.

Hyperbaric oxygen therapy (HBQ) has been used for several years as a treatment for Ménière's disease, particularly in Sweden. In this study continuous variations in pressure (from 1.7 to 2.2 ATA; alternobaric oxygen therapy: ABOT) were used to decrease endolymphatic hydrops, the typical histopathological substrate of Ménière's disease by increasing hydrostatic pressure and mechanical stimulation of the endolymphatic flow toward the duct and the endolymphatic sac, which produces a consequent increase in the dissolved O2 content in the labyrinth liquid, which should contribute to recovering cell metabolism and restoring cochlear electrophysiological function to normal. An experimental group of 20 patients suffering from unilateral Ménière's disease received a total of 15 ABOT treatment sessions during the acute episodes. Treatment foresaw two days without therapy every five days of application. Maintenance treatment consisted of one session per day for five consecutive days every month for one year. Thereafter, during the second, third, and fourth years of treatment, patients were submitted to one session per day for five consecutive days every three months. A control group of 18 patients suffering from Ménière's disease was treated with 10% glycerol i.v. (during the acute episodes) and with betahistine (8 mg x 3/day) in the periods in between. Mean pure tone average (PTA in dBHL) hearing thresholds at octave frequencies from 500 to 3,000Hz, and frequency of episodes of vertigo and tinnitus, both after 15 days of treatment and at the end of a four-year follow-up, were compared for both groups according to the 1995 Committee on Hearing and Equilibrium criteria. No statistically significant differences were found between the two groups at the end of the first 15 days of treatment. However, at the end of the follow-up period, patients treated with ABOT had significantly fewer vertiginous episodes and improved PTAs and tinnitus compared to the controls. The results support the use of ABOT as a valid alternative to drugs in the long-term treatment of Ménière's disease.

Sudden hypoacusis treated with hyperbaric oxygen therapy: a controlled study.

The term sudden hypoacusis describes a hearing loss of rapid onset and unknown origin that can progress to severe deafness. Of the many therapeutic protocols that have been proposed for treating sudden hypoacusis, hyperbaric oxygen therapy (HOT) plays a leading role. We studied 50 patients who had been referred to our ENT unit within 48 hours of the onset of sudden hypoacusis. We randomly assigned 30 of these patients to undergo once-daily administration of HOT for 10 days; the other 20 patients were treated for 10 days with an intravenous vasodilator. Response to therapy in all patients was evaluated by calculating the mean hearing threshold at frequencies between 500 and 4,000 Hz and by assessing liminal tonal audiometry results recorded at baseline and 10 days after the cessation of treatment. These results, plus the findings of other audiologic and otoneurologic examinations, revealed that the patients in the HOT group experienced a significantly greater response to treatment than did those in the vasodilator group, regardless of age and sex variables. Significantly more patients in the HOT group experienced a good or significant response. In both groups, patients with pantonal hypoacusis responded significantly better than did those with a milder condition. Based on our findings, coupled with the fact that oxygen therapy is well tolerated and produces no side effects, we conclude that HOT should be considered the preferred treatment for patients with sudden hypoacusis.

[Oxygen therapy in the long term treatment of Meniere's disease]. / L'ossigenoterapia nel trattamento a lungo termine della malattia di Ménière.

Endolymphatic hydrops is the hystopathological substrate characteristic of Ménière's disease. Besides the classical treatment with diuretics and/or osmotic drugs for some time, now treatment in a "pressure chamber" (OTI) has also been applied. The oxygen administered in the hyperbaric chamber can reduce the hydrops both by increasing the hydrostatic pressure and by mechanically stimulating the flow of endolymph toward the duct and endolymphatic sac. In addition, an increase is seen in the amount of O2 dissolved in the labyrinthine fluids and this contributes to recovering cell metabolism and restoring normal cochlear electrophysiological functions. Between 1992 and 1996 40 patients with monolateral Ménière's disease were studied: 15 underwent oxygen therapy at a constant pressure (2.2 ATA) (HOT), 25 with a continuous variation in pressure (from 1.7 to 2.2 ATA) (Alternobaric therapy, AOT). During the acute phase the patients underwent daily OTI treatment for 15 days in a row. The maintenance treatment called for one treatment cycle (one session a day for 5 days in a row) a month for 1 year, followed by for one treatment cycle (one session a day for 5 days in a row) every three months during the 2nd, 3rd and 4th years. The controls consisted of a group of 18 patients treated with 10% glycerol i.v. (during the acute phase) and betahystine (8 mg x 3/die) between episodes. A comparison was made of the average hearing threshold for the frequencies 500-3000 Hz (PTA), how frequently episodes of dizziness arose and extent of hearing loss in the three groups after the initial 15 days of treatment and at the end of the 4-year follow-up, in compliance with the criteria laid down by the Committee on Hearing and Equilibrium in 1995. At the end of the first 15 days of treatment, there were no statistically significant differences between the three groups. At the end of the follow-up, on the other hand, hyperbaric treatment, and in particular alternobaric therapy, enabled a significant reduction in the episodes of dizziness as compared to the control group. PTA and deafness also improved significantly in the patients who had undergone hyperbaric treatment. The results of the present work show that HOT, and in particular AOT, offer a valid alternative to drugs in the treatment of Ménière's disease.