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Biomedical subjects

C Lanteri

Publications and source records attributed to C Lanteri.

13 recordsLinked to original sources

Non-invasive determination of alveolar pressure during mechanical ventilation.

The development of inadvertent positive end-expiratory pressure (PEEPi) in ventilated infants is of clinical relevance and difficult to measure non-invasively. A method for estimating end-expiratory alveolar pressure by applying a multiple regression analysis to airway opening pressure, flow and volume recordings during mechanical ventilation was evaluated. In eight open-chested, paralysed and mechanically ventilated mongrel dogs, alveolar pressure was measured directly with "alveolar capsules". Alteration of ventilation patterns and addition of a resistive element were used in three dogs to induce different levels of PEEPi. End-expiratory alveolar pressure measured directly and determined from multilinear regression of airway opening pressure correlated well (mean error 0.06 +/- 0.53 (+/- SD) hPa, limits of agreement -1.16 to +1.04 hPa). The other five dogs received inhalation challenges, two with histamine, two with hypertonic saline and one with methacholine resulting in a mean increase of respiratory system resistance of 230% (range 141-489%) of the baseline values. The mean error in determining PEEPi was 0.54 +/- 0.37 hPa, the limits of agreement were -0.20 to 1.28 hPa. The method was then applied to seven mechanically-ventilated children (aged 2 months to 8 yrs, weight 4.9-23.5 kg) and the results were compared to the pressure at which inspiration began (equalling PEEPi). Seventy eight measurements were performed during open heart surgery, while compliance changed by between 3 and 186% of baseline values due to the surgical procedures. PEEPi estimated by multiple regression agreed well with the pressure at which inspiration began (mean difference 0.25 +/- 0.68 hPa, limits of agreement -1.12 to 1.62 hPa).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals

Effect of the thermodynamics of an infant plethysmograph on the measurement of thoracic gas volume.

Adult plethysmographs have frequency responses that are essentially flat over the range of frequencies encountered in the measurement of thoracic gas volume (TGV). An infant plethysmograph is necessarily much smaller than an adult model. This means that there is a smaller mean distance over which heat diffusion must occur between the air in the plethysmograph and its walls. This in turn leads to a much reduced thermal time constant. We examined the effects of thermal time constant of a 60 L infant plethysmograph on measurements of TGV in infants. The thermal time constant was measured by rapidly injecting 20 mL of air into the plethysmograph, and found to be 0.16 +/- 0.09s when the box was empty. We calculated from this time constant that measurements of TGV should be quite dependent on the frequency at which the associated panting maneuvers are performed. TGV was measured in 5 infants less than 6 months old in the recovery phase following acute viral bronchiolitis. When we performed a digital correction of the measurements, to compensate for the thermal time constant of the plethysmograph, the TGV values decreased by a mean of 12%. Agitating the air in the plethysmograph with a fan decreased the thermal time constant of the box and reduced measured TGV by a mean of 8.4%. These results indicate that thermodynamics of infant plethysmographs can be an important source of error in TGV measurements.

Algorithms

[Relationship of orthodontics and periodontal support].

The Authors, in the light of available data in the published literature and using their own personal experience as a basis, examine the relationship existing between orthodontia and periodontology, giving prominence to the more immediate and dynamic aspects of the comparison. An obvious cause-and-effect relationship often links the position of the teeth and the periodontal pathology; if this relationship is understood by the orthodontist, it can guide him in his choice of treatment, both where curative treatment is required but also, and more importantly, where prevention can be provided. Emphasis is placed on how serious can be the damages caused to the periodontium where the monitoring of the bacterial plaque and of the inflammation which it brings about is not sufficiently constant. Certain programs of treatment are proposed which, using orthodontal methods, can make a substantial contribution to solving periodontal problems, the kind of problems which are hard to control when traditional methods are used.

Adolescent

[Bonding of "E"].

When mixed dentition therapy is indicated, the Authors suggest the banding of second deciduous molars to avoid the risk of demineralization of first permanent molars. The method suggested is supported by few clinical cases, shown in the figures, where heavy forces are exerted against the second deciduous molar.

Child

[Dyslalia and orofacial dysmorphism].

In the light of reported data and personal experience, relations between malocclusions and dyslalias are examined. Although the coexistence of malocclusions and dyslalia is a frequent clinical observation, correlations between the two conditions do not appear to be closely linked by any clearly identifiable cause-effect relationship. Considering the high number of aetiological factors involved, stress is laid on the need for a multidisciplinary approach to cases that present contemporaneously malocclusions and dyslalias in the interests of correct diagnosis and rational therapeutic orientation.

Cleft Palate