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Biomedical subjects

O Perier

Publications and source records attributed to O Perier.

At least 19 recordsLinked to original sources
PubMed1992

Treatment of chronic hyponatremia in rats by intravenous saline: comparison of rate versus magnitude of correction.

The role of the rate of correction in the development of demyelinating brain lesions after correction of chronic severe hyponatremia is controversial. It has been recently suggested in rats treated by intravenous (i.v.) hypertonic saline (NaCl) that both the rate and the absolute change in serum sodium represent critical risk factors. However, we previously demonstrated in rats treated by intraperitoneal (i.p.) injections of NaCl that below a threshold of serum sodium rise of 20 mEq/liter/24 hr, only 5% of the brain lesions were recorded, even in rats submitted to a rapid (1 hr) serum sodium increment following the i.p. injection. Working below this threshold (serum sodium rise less than 20 mEq/liter/24 hr) in the present work, allowed us to independently determine the role of the rate in the outcome of the correction. This was done by submitting the rats to a rapid (1 hr) intravenous infusion of NaCl. As a difference between the i.p. and i.v. route in the degree of volume expansion produced by the NaCl administration could also play a role in the pathogenesis of the brain lesions, rats treated with rapid i.v. infusion of NaCl (associated with volume expansion) were compared to a group of rats treated with water restriction (associated to volume contraction) to evaluate the role of volemia on the incidence of neurological damage. Hyponatremia was induced over three days with d-glucose in water and vasopressin. The group 1 was corrected by intravenous (i.v.) infusion of hypertonic saline over one hour.(ABSTRACT TRUNCATED AT 250 WORDS)

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PubMed1991

Limits of brain tolerance to daily increments in serum sodium in chronically hyponatraemic rats treated with hypertonic saline or urea: advantages of urea.

1. At present there is no consensus about the optimal management of hyponatraemia to prevent demyelinating brain lesions. We have evaluated in a large series of rats (n = 136) the protective role of urea for the brain in the treatment of severe chronic hyponatraemia. Urea (group I, n = 51) was compared with hypertonic saline in boluses (group II, n = 46) and with hypertonic saline in divided doses (group III, n = 39). Treatment was administered intraperitoneally over 48 h. The severity of brain lesions was assessed by histological scoring. 2. For 95% of the injured animals treated with hypertonic saline, brain lesions appeared for an absolute increment in serum Na+ concentration (delta SNa+) of 20 mmol day-1 l-1. Above this limit neurological injuries gradually worsened, and beyond a transition zone (delta SNa+ greater than or equal to 20 less than or equal to 23 mmol day-1 l-1) 89% (group III) to 100% (group II) of the animals were injured. This limit can be reached rapidly, as attested by the comparable severity of brain lesions observed in group II (mean delta SNa+ 1 h after a bolus injection, 19 mmol/l) and in group III (mean delta SNa+ 1 h after an injection, 2 mmol/l), both groups achieving similar daily delta SNa+. 3. A correction above the threshold of 20 mmol day-1 l-1 is as toxic during the first 24 h as during the second day of the treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

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PubMed1985

[Rehabilitation programs for patients with cochlear implants as a function of acquired experience in logopedics for deaf children].

Rehabilitation of patients after cochlear implant surgery should be planified along the same basic principles as those that have been envolved for the adaptation of patients to a classical hearing aid or acoustic prosthesis. When this is adapted to a patient with a sensorineural hearing loss, the quality of hearing differs from that of normal hearing because the pathological inner ear introduces distorsions. The patient therefore has to be trained to equate the new auditory sensations with those he had previously, which is basically the same situation as with a cochlear implant. Some profoundly or totally deaf patients are fitted with vibro-tactile aids and they also have to be trained to make use of these new sensations in a meaningful way for an aid to speech understanding. For the above reasons the term "cochlear prosthesis" is considered particularly adequate. It also has the advantage of playing down the surgical aspect of this new technique, often overemphasized by the media and creating exaggerated emotional involvement of the patients. If the above facts are recognized, one should entrust the rehabilitation of patients fitted with cochlear prostheses to logopeds (speech therapists) well trained in the habilitation and prosthetic adaptation of profoundly deaf children. Only they have the expertise necessary to devise and apply a program founded upon experience. This will help avoid the pitfalls into which several surgically directed cochlear implant teams are currently falling. One of these is to design a training program in function of the tests meant to measure the patients' new capacities.(ABSTRACT TRUNCATED AT 250 WORDS)

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