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Biomedical subjects

O Parra

Publications and source records attributed to O Parra.

At least 19 recordsLinked to original sources
PubMed2000

Time course of sleep-related breathing disorders in first-ever stroke or transient ischemic attack.

To investigate the prevalence and behavior of sleep-related breathing disorders (SRBDs) associated with a first-ever stroke or transient ischemic attack (TIA), we prospectively studied 161 consecutive patients admitted to our stroke unit. Complete neurological assessment was performed to determine parenchymatous and vascular localization of the neurological lesion. Stroke subtype was categorized as TIA, ischemic (IS), or hemorrhagic (HS). A portable respiratory recording (PRR) study was performed within 48-72 h after admission (acute phase), and subsequently after 3 mo (stable phase). During the acute phase, 116 patients (71.4%) had an apnea-hypopnea index (AHI) > 10 events/h and 45 (28%) had an AHI > 30. No relationships were found between sleep-related respiratory events and the topographical parenchymatous location of the neurological lesion or vascular involvement. Cheyne-Stokes breathing (CSB) was observed in 42 cases (26.1%). There were no significant differences in SRBD according to the stroke subtype except for the central apnea index (CAI). During the stable phase a second PRR was performed in 86 patients: 53 of 86 had an AHI > 10 and 17 of 86 had an AHI > 30. The AHI and CAI were significantly lower than those in the acute phase (16.9 +/- 13.8 versus 22.4 +/- 17.3 and 3.3 +/- 7.6 versus 6.2 +/- 10.2, respectively) (p < 0.05) while the obstructive apnea index (OAI) remained unchanged. CSB was observed in 6 of 86 patients. The prevalence of SRBD in patients with first-ever stroke or TIA is higher than expected from the available epidemiological data in our country. No correlation was found between neurological location and the presence or type of SRBD. Obstructive events seem to be a condition prior to the neurological disease whereas central events and CSB could be its consequence.

Aged↗
PubMed1999

Blood metabolites and their relationship with production variables in dual-purpose cows in Venezuela.

A survey was carried out on 79 lactating Bos taurus/indicus cross-bred cows on three dual-purpose cattle farms to measure the blood concentration of metabolites and to evaluate possible relationships with nutritional status and productive variables. A rotational grazing system on Star grass and other tropical pastures (10-12% CP in leaves) was used and 2-3 kg/cow/day of concentrate were fed on two farms. Restricted calf suckling was used in two herds. Average milk yield sold per farm was 6 kg/day/cow and body condition scores (BCS) were between 3.0 and 3.8 on a scale of one-to-five. On two farms, the average interval from calving to conception (ICC) was more than 145 days. Mean blood concentrations of albumin, globulin, urea, beta-hydroxybutyrate and phosphorus were generally within reference values, but a significant group of cows had low levels of albumin and urea and high levels of globulin. Packed cell volume (PCV) was below normal values, with anemia in 63% of cows during the second trimester of lactation, which was negatively correlated to milk yield. The high incidence of anemia could be related to factors such as hematophagic parasites, not evaluated in this study. ICC values were negatively related to albumin level and could be associated with protein deficiency in the diet or with disease, as globulin values were high in many cows. Based on these diagnoses, an experiment was carried out on one of the farms to evaluate the influence of supplementation with 0.5 kg/cow/day of fish meal. Total milk yield was not influenced by the fish meal and reproductive efficiency was high in the two supplemental treatments. It was shown that supplementation with undergraded protein is not required in these cows.

3-Hydroxybutyric Acid↗
PubMed1997

Should patients with sleep apnoea/hypopnoea syndrome be diagnosed and managed on the basis of home sleep studies?

The purpose of this study was to analyse the validity and the economic efficiency of a portable monitor of respiratory parameters (PMRP), used in a home setting for the diagnosis of sleep apnoea/hypopnoea syndrome (SAHS). Eighty nine patients with suspected SAHS were studied in two settings: in the sleep laboratory using full-polysomnography (full-PSG); and at the patient's home using a PMRP. In the home setting, 50 patients were assisted by a technician and 39 set up the equipment themselves. SAHS (apnoea/hypopnoea index (AHI) >10 events x h(-1) by means of full-PSG) was diagnosed in 75 of the 89 patients. An acceptable agreement was obtained between the AHI measured by full-PSG and PMRP, according to the Bland and Altman method of concordance (mean bias 2.56; 95% confidence interval 3.25). Sensitivity and specificity of PMRP were adequate for diagnostic purposes; however, their values rely on the prior PMRP-AHI cut-off point selected with reference to full-PSG-AHI >10. The clinical therapeutic decision taken after PMRP agreed with that taken with full-PSG in 79 patients (89%). Although 10% of the studies with an individual set-up needed repetition, both of the domiciliary modalities (with and without a technician's intervention) were, economically, about three times more efficient than full-PSG. In conclusion, we believe that patients with a suspected sleep apnoea/hypopnoea syndrome should initially be studied in a home setting with a portable monitor of respiratory parameters, since it is a reliable method with an acceptable cost-effective profile.

Adult↗
PubMed1996

Determination of aromatic metabolites in ruminant urine by high-performance liquid chromatography.

A method based on reversed-phase HPLC is reported for the separation and quantification of various urinary aromatic metabolites: hippuric, phenylaceturic, salicyluric, benzoic, phenylacetic, salicylic, 3-phenylpropionic and cinnamic acids and several phenols in ruminant urine. In this method, a Nova-Pak C18 (4 microns) 150 x 3.9 mm I.D. column, two solvents [A: 15% methanol in 20 mM acetic acid (pH 3.3); B: methanol) in a gradient mode at a flow-rate of 0.8 ml/min, and UV detection at 210 nm were used. Quantification of the total (free and conjugated) benzoic, phenylacetic and salicylic acids present in urine was achieved by hydrolysis of the samples in 3 M HCl at 100 degrees C for 24 h prior to HPLC analysis. The lowest detection concentration was 50 mumol/l. This method is useful for scanning the profile of aromatic metabolites in urine of ruminants, which provides information on the diets the animals receive.

Animals↗
PubMed1996

Comparison of partially attended night time respiratory recordings and full polysomnography in patients with suspected sleep apnoea/hypopnoea syndrome.

BACKGROUND: Laboratory full polysomnography (PSG) is considered to be the gold standard for the diagnosis of the sleep apnoea/hypopnoea syndrome (SAHS), but it is expensive and time consuming. A study was undertaken to evaluate the diagnostic usefulness of a partially attended night time respiratory recording (NTRR) and a clinical questionnaire in patients with suspected SAHS in comparison with full PSG. METHODS: Seventy six patients (54 men) of mean (SD) age 51 (11.5) years with a body mass index of 31 (5.7) kg/m2 were studied at random on two different nights with full PSG at the sleep laboratory and with NTRR on a respiratory ward. NTRR records oximetry, airflow, chest and abdominal motion. All signals were continuously displayed on a computer screen throughout the night and respiratory events were scored automatically the following morning. All patients completed a clinical questionnaire. RESULTS: Mean values of the apnoea/hypopnoea index (AHI) using NTRR were lower than those obtained with full PSG (22.7 (2.4) versus 32.2 (3) events/hour) which was mainly due to underrecognition of hypopnoeas. Sensitivity and specificity of NTRR for the diagnosis of SAHS were 82% and 90%, respectively, taking as reference AHI > 10 on full PSG (AHI-PSG > 10). The mean (+/-2SD) difference in AHI between the two methods was 9.6 (range -5.4-24.6) (95% confidence interval 6.2 to 13). Symptoms of witnessed apnoeas, impotence, the overall clinical impression of a trained physician, and a neck size over 40 cm were significantly more prevalent in patients with AHI-PSG of > 10, but impotence was the only clinical feature significantly more prevalent in patients with false negative compared with true negative NTRR results that helped to distinguish patients with NTRR < 10 but AHI-PSG > 10. CONCLUSIONS: NTRR is a helpful and easy complementary diagnostic tool in clinical practice because it detects patients with moderate to severe SAHS reasonably well and therefore can be useful for confirming a diagnosis of SAHS and also for treatment decisions. It is suggested that patients with suspicion of SAHS should be initially studied by NTRR. When NTRR is negative, a full PSG should be performed if witnessed apnoeas, impotence, systemic hypertension, ischaemic heart disease, and a trained physician's clinical impression of SAHS are present.

Adult↗
PubMed1996

[Human ehrlichiosis: report of the 1st case in Venezuela].

Human ehrlichiosis is a zoonotic disease, caused by a rickettsia that infects leukocytes. It was described for the first time in the United States of America in 1986. More than 300 cases have been reported in that country. One case has been reported in Portugal, two in France and one more in a tourist coming from Mali (Africa). In Venezuela, a tropical country, where ehrlichiosis is endemic in dogs and horses, the first case of human ehrlichiosis is reported in a seventeen month old girl. She initially had symptoms compatible with a viral illness. Then she developed a rash, acute respiratory failure, hepato-splenomegaly, neurologic abnormalities, renal failure and hematologic alterations including pancytopenia and disseminated intravascular coagulation (DIC). Different diagnoses were given before it was concluded that it was a case of ehrlichiosis. She was treated with tetracycline and very soon recovered. The initial diagnosis was made using buffy coat blood smears stained with Diff Quick Stain. Indirect Immunofluorescence (IFA) test was used to detect antibodies against Ehrlichia chaffeensis (1:126) but not to other rickettsias. Also the presence of platelets with ehrlichia bodies similar to E. platys from dogs, it was demonstrated, in peripheral blood from the child. The presence of these bodies in human platelets has not been previously reported. In this case, it could not be proved that the disease was transmitted by a tick bite. The presence of ehrlichia bodies in platelets from the girl's peripheral blood is also described.

Adolescent↗
PubMed1995

Prognostic factors of pneumonia requiring admission to the intensive care unit.

All patients with severe pneumonias (community-acquired and nosocomial) who required treatment in the intensive care unit (ICU) were included in a 3-year prospective study. Predictive factors for a fatal outcome were analyzed in 127 patients. An etiologic diagnosis was made in 70 (55.1%) patients. Culture of sputum or tracheobronchial secretions were used only as criteria for microbiologic diagnosis of Legionella pneumophila. The pathogens most frequently identified were L pneumophila, Streptococcus pneumoniae, and Pseudomonas aeruginosa. Viruses were not detected as causative agents. A total of 54 patients died (mortality rate, 42.5%). The univariate analysis showed the following factors associated with mortality: advanced age (> or = 70 years); presence of septic shock, requirement of mechanical ventilation, and Simplified Acute Physiology Score [SAPS] index > 12 at the time of admission to the ICU or when symptoms appeared in patients already admitted to the ICU; development of any complication during ICU hospitalization; and P aeruginosa as the etiologic agent of the pneumonia. When all variables were introduced by a stepwise method, the final model included advanced age (> or = 70 years), SAPS index > 12, presence of septic shock, requirement of mechanical ventilation, bilateral pulmonary involvement, and P aeruginosa as the etiologic agent of pneumonia as prognostic factors associated with a fatal outcome.

Adolescent↗
PubMed1994

[A decrease in the level of CPAP required after prolonged treatment in patients with the obstructive sleep apnea syndrome].

Application of continuous positive upper airway pressure (CPAP) is the treatment of choice in obstructive sleep apnea syndrome (OSAS). CPAP keeps the upper airway open by providing a "pneumatic splint" on the pharyngeal walls. However, it has been suggested that prolonged nasal CPAP treatment may also improve the physiopathological mechanisms responsible for OSAS by a variety of mechanisms such as the reduction of edema of the pharyngeal mucosa, modification of upper airway muscle dynamics; there may even be a reduction in the intensity of phenomena responsible for brief awakening and ending of apneic episodes. The objective of this study was to determine whether prolonged nasal CPAP is associated to a reduction of CPAP pressure required for eliminating apnea in patients with OSAS. We studied 22 patients (4 women) with OSAS diagnosed by conventional polysomnography, including study of neurological variables during sleep (electroencephalogram, ocular movement, submental electromyogram), respiratory variables (nasal air flow, thoracic-abdominal movement, O2 saturation in the blood), and others (electrocardiogram, leg movement). Treatment was exclusively with nasal CPAP. All 22 patients were middle-aged (52.3 +/- 10 years), presented a mean apnea/hypoapnea index of 65.2 +/- 24 per hour. CPAP levels needed to eliminate episodes of apnea, blood O2 desaturation and snoring at the time of diagnosis and after long-term treatment (8.5 +/- 4.6 months) were applied. Weight was recorder at both measurement times. Eighteen of the 22 patients (1 woman, mean age 53.1 +/- 11.4 years and apnea/hypopnea index 64.8 +/- 23.4 per hour) experienced no weight change during treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Hygroscopic condenser humidifier as a solution to nasal dryness due to nasal CPAP treatment for obstructive sleep apnea syndrome.

We report an apparent solution to nasal dryness for patients with obstructive sleep apnea syndrome treated with nasal continuous positive airway pressure (CPAP) when a hygroscopic condenser humidifier is introduced into the CPAP circuit. Six patients underwent a 5-h test period of nasal CPAP therapy with a mask containing a hygroscopic humidifier. The water vapor showed a statistically significant increase in both inspired and expired gases. The relative humidity of the inspired gases increased significantly. The levels of O2 and CO2 in the respired gases did not change. When patients were asked about nasal dryness at the end of the test, all of them reported marked improvement.

Air Conditioning↗
PubMed1989

[Early detection of tuberculosis by the evaluation of contacts].

We have evaluated the close contacts of 191 patients diagnosed of tuberculosis in our center between 1984 and 1987. The overall number of evaluated contacts was 666, and the mean number of contacts for each index case was 3.7. In 55% of the evaluated population PPD reaction was positive, and their mean age was 33.3 years. In 132 cases chemoprophylaxis was given during one year (22%). Forty-one new cases of tuberculosis were detected, with a mean age of 25.6 years. In ten new cases the source of infection was familial. When the contacts were distributed according to the bacteriologic status of the index case (direct investigation of tubercle bacilli positive in 103 cases and negative in 167), the rate of disease and infection was significantly higher among those related to positive patients. In the group related to negative patients we discovered 7 new cases of active tuberculosis. Our results confirm the usefulness of the systematic evaluation of the contacts of tuberculous patients in our area, as it permits the identification of an important number of new patients which should be adequately treated. This practice contributes to interrupt the epidemiologic transmission chain of the disease and to facilitate its eradication.

Adolescent↗
PubMed1989

Amiodarone toxicity: recurrence of interstitial pneumonitis after withdrawal of the drug.

Amiodarone hydrochloride, an iodinated benzofuran derivative, is effective for treatment of supraventricular and ventricular arrhythmias. Pulmonary fibrosis has been reported after treatment with this drug. We present a patient with amiodarone pulmonary toxicity, who initially responded to corticosteroid therapy, but who developed a clinical relapse two months after withdrawal of the drug.

Amiodarone↗