Un mecanismo nefrogénico subyace a la poliuria inducida por dexmedetomidina: informe de un caso / Nephrogenic mechanism underlies dexmedetomidine-induced polyuria: A case report

La dexmedetomidina, agonista del adrenorreceptor α, se utiliza cada vez más como agente sedativo-hipnótico y analgésico, aunque su popularidad suscita preocupación acerca de los efectos secundarios de dicho fármaco.La bradicardia y la hipotensión son efectos adversos comunes, pero también existen diversos informes de gasto urinario excesivo, posiblemente debido a la secreción de vasopresina y a la permeabilidad de los conductos colectores.La poliuria se resuelve normalmente con la discontinuación del fármaco, no habiéndose reportado morbilidad significativa. La identificación temprana, la eliminación del agente y el tratamiento son imperativos para minimizar las complicaciones, principalmente natremia y síntomas neurológicos.Este informe de caso describe la poliuria relacionada con dexmedetomidina durante la anestesia general libre de opioides para cirugía mayor de cabeza y cuello. Nuestra hipótesis de etiología nefrogénica se ve reforzada por los datos analíticos obtenidos. También describimos cómo abordar la poliuria intraoperatoria. (AU)

Dexmedetomidine's α-adrenoreceptor agonism has been gaining popularity in the anesthetic room as a sedative-hypnotic and analgesic agent, and with extensive perioperative use rising concern about side effects is necessary.Bradycardia and hypotension are common but excessive urine output is increasingly reported, suggested mechanisms being vasopressin secretion and increasing permeability of the collecting ducts.Polyuria usually resolves with discontinuation of the drug and significant morbidity has not been reported. Early identification, removal of agent and treatment are imperative to minimize complications, mainly associated with natremia levels and neurological symptoms.This case report describes a dexmedetomidine-related polyuric syndrome during opioid-free general anesthesia for major head and neck surgery. A nephrogenic mechanism for the clinical effect is proposed and reinforced by analytical data obtained. An intra-operative polyuria approach is also delineated. (AU)

A nephrogenic mechanism underlies dexmedetomidine-induced polyuria. A case report.

Dexmedetomidine's α-adrenoreceptor agonism has been gaining popularity in the anesthetic room as a sedative-hypnotic and analgesic agent, and with extensive perioperative use rising concern about side effects is necessary. Bradycardia and hypotension are common adverse effects, but there are also several reports of excessive urine output, possibly due to vasopressin secretion and permeability of collecting ducts. Polyuria usually resolves with discontinuation of the drug, and significant morbidity has not been reported. Early identification, removal of the agent, and treatment are imperative to minimize complications - mainly natremia and neurological symptoms. This case report describes a dexmedetomidine-related polyuric syndrome during opioid-free general anesthesia for major head and neck surgery. A nephrogenic mechanism for the clinical effect is proposed and reinforced by analytical data obtained. An intra-operative polyuria approach is also delineated.

Epworth Sleepiness Scale in obstructive sleep apnea syndrome--an underestimated subjective scale.

Excessive daytime sleepiness is a major symptom in obstructive sleep apnea syndrome (OSAS) and can be evaluated using both subjective and objective methods. The Epworth Sleepiness Scale (ESS) is a simple and validated questionnaire for assessing subjective daytime sleepiness in the context of sleep disorders. Although its subjective character may limit the accurate expression of daytime sleepiness, the clinical benefit of sequential ESS is clear and demonstrates how ESS scores evolve in individual patients and how these scores may relate to various parameters. In this context we compared the severity of daytime sleepiness reported at baseline visit with severity of baseline sleepiness assessed, retrospectively, after treatment with automatic positive airway pressure (APAP). We conducted a prospective study that included 66 patients evaluated in a sleep clinic diagnosed with OSAS. The diagnosis was confirmed by in-laboratory or portable sleep studies. Their mean age was 53.3 years and the majority were men (88%, n=58). The ESS was answered during the first interview (baseline daytime sleepiness). During follow-up visits, after APAP treatment, the patient was asked to assess baseline sleepiness, retrospectively, as well as post-treatment sleepiness. The mean baseline ESS score was 11.8, mean retrospective baseline ESS 15.4, with a mean difference of 3.55 (p<0.001 t-Test) and post-treatment ESS 7.3. There was no significant correlation between the difference in ESS score (baseline - retrospective baseline) with the average daily (hours) use of APAP, the apnea-hypopnea index (AHI), the minimal recorded SatO(2), disease duration, body mass index (BMI) and age. Our findings confirm that the severity of subjective sleepiness reported before treatment with positive airway pressure is often underestimated by patients with OSAS.

Severe α-1 antitrypsin deficiency caused by Q0(Ourém) allele: clinical features, haplotype characterization and history.

α-1 Antitrypsin deficiency (AATD) caused by null alleles is associated with the total lack of protein and generally it translates into more severe clinical features of pulmonary disease. This is the case of Q0(Ourém) , a rare variant found in several families of Central Portugal caused by the L353fsX376 mutation. A total of 41 patients carrying at least one copy of Q0(Ourém) were evaluated for SERPINA1 levels, respiratory function values and lung parenchyma status (chest X-ray and computerized tomography scan). Q0(Ourém) haplotype background was characterized using seven microsatellites flanking SERPINA1 and Q0(Ourém) age was estimated by a statistical method relying on the decay of haplotype sharing at linked markers (DHSMAP). Homozygous patients showed a compromised lung function and extensive emphysema. SQ0(Ourém) , although having serum levels below the 11 µM threshold, did not necessarily result in signs of disease. MQ0(Ourém) were found to be a heterogeneous group, mainly composed of normal individuals. Eight Q0(Ourém) haplotypes were identified and the allele was estimated to have arisen 650 years ago. Q0(Ourém) was associated with mild to severe AATD and has a single origin, probably linked to the major Ourém settlements where the occurrence of severe AATD may not be explained by recent consanguinity.

[Anatomy for the bronchologist: a prospective study of the normal endobronchial anatomic variants]. / Anatomia endobrônquica: estudo prospectivo das variações anatómicas da árvore traqueobrônquica.

A comprehensive knowledge of the normal pattern of endobronchial branching is essential to any pulmonologist. The classification systems available are predominantly static descriptions and only seldom do they refer to possible variations within the normal spectrum. To evaluate all possible anatomical variants of the tracheobronchial tree we conducted a prospective study in our endoscopy unit between February, 1st and July, 10th (2009). A total of 181 individuals were included in the study. Anatomical variants were found to be present in 79 individuals (43% of total). Overall we found 20 different anatomical variants. Variations were more frequently found within the right upper lobe (16.6% of individuals). Middle lobe and lingula presented no variations. The variant most frequently found was the presence of a bifurcate pattern of the right upper bronchus (13.8%). The present study revealed a relatively high frequency of anatomical alternatives to the normal endobronchial branching pattern. Recognition of these variants and the frequency of their expression are fundamental for the bronchologist in establishing the limits of normal anatomy and preparing endobronchial techniques or surgical procedures.