PubMed Health⌕ Search

Biomedical subjects

M Valdes

Publications and source records attributed to M Valdes.

At least 19 recordsLinked to original sources
PubMed2000

[Risk factors and prognostics of urinary infections due to gram-negative bacteria].

Urinary infections due to gram-negative bacteria are important because of their high frequency, morbidity and mortality. In order to evaluate the risk factors and prognostics a group of 50 patients with nosocomial urinary infections were studied prospectively and consecutively and were compared with another group of 50 patients with similar characteristics but no infection. The most isolated bacteria were Escherichia coli (68%), followed by Pseudomonas aeruginosa (20%). Bacteremia was found in 22% of the cases. Risk factors included female gender, medical services, nosocomial acquisition, previous use of manipulation techniques such as vesicular probe, prior urinary infections, and the use of cytostatic drugs in the previous six weeks. Mortality was 4%. The factors significantly associated with a poor prognosis were the following: severe underlying disease, a clinically critical situation, previous surgery, complications, type of gram-negative bacteria, use of third generation cephalosporins and ciprofloxacin in the previous six weeks and older age. The mortality of the control group was 8%.

Adult↗
PubMed2000

[Risk factors and prognostics of nosocomial infectionof surgical wounds in a general hospital].

Surgical infections due to gram-negative bacteria are important because of their high frequency, morbidity and mortality. In order to evaluate the risk factors and prognostics of gram-negative surgical wound infections a group of 50 patients with surgical infections were studied prospectively and consecutively and were compared with another group of 50 patients with similar characteristics but no infection. No significant differences were observed with respect to age between the two groups. Previous surgery, prior surgical infections and use of wide-spectrum antibiotics in the six weeks before the study were significantly associated with the development of surgical wound infections due to gram-negative bacteria. The most isolated bacteria were Pseudomonas aeruginosa (34%), followed by polymicrobial flora (16%). The factors significantly associated with a poor prognosis were the following: severe underlying disease, a clinically critical situation, previous surgery, arterial hypertension, complications, type of gram-negative bacteria, prior use of wide-spectrum antibiotics in the previous six weeks and older age. No deaths occurred.

Cross Infection↗
PubMed2000

[Influence of serious infections due to Gram-negative bacteria on the hospital economy].

Nosocomial infections due to Gram-negative bacteria are very important since they are associated with high morbidity and high hospital costs. A prospective study of 250 inpatients was carried out, 200 of whom had Gram-negative bacterial infections. Patients were divided into groups of 50 according to the localization of the infection (urinary, surgical wound, respiratory tract and bacteremia), with a control group of 50 patients with similar characteristics but no infection. We calculated the cost for the different groups by multiplying the average length of hospital stay in days by the daily cost of the stay. Significant differences were observed in the average length of stay per patient according to the type of infection and how it was acquired. In terms of cost, nosocomial infection due to Gram-negative bacteria was 1,049,139 pesetas more expensive than community-acquired infection. The cost of the stay for patients with postsurgical infection due to Gram-negative bacteria was 1,108, 252 pesetas more expensive than for the group of control patients. Nosocomial infection due to Gram-negative bacteria is associated with a prolongation in hospital stay of 9 to 28 days, which is the factor that most reflects the cost that can be attributed to nosocomial infection. Consensual and protocolized measures which allow for better clinical management need to be developed.

Cross Infection↗
PubMed2000

[Prospective, comparative study (1994-1998) of the influence of short-term prophylactic treatment with azithromycin on patients with advanced COPD].

Despite the advances in therapy, chronic obstructive pulmonary disease (COPD) requires frequent hospital admissions due to acute exacerbations. We carried out a prospective randomized study of two groups of patients with COPD, one (n = 54) treated with azithromycin (500 mg/day) for three days every 21 days during the winter months, and a control group (n = 40) without treatment. A statistically significant reduction in the number of acute infectious episodes (187) and hospital admissions (22) was observed in the treated group versus the control group (249 and 45, respectively). A short prophylactic treatment course with azithromycin is a good alternative in the management of patients with severe, advanced COPD, and could lead to an improvement in social and healthcare costs

Aged↗
PubMed1999

Unusual congenital coronary anomaly and myocardial ischaemia.

Angiography was used to diagnose a rare congenital coronary anomaly with myocardial ischaemia in a woman with typical angina. All three coronary arteries arose from a solitary coronary ostium in the right aortic sinus; the left anterior descending coronary artery followed a septal course, the circumflex coronary artery ran behind the ascending aorta, and the right coronary artery followed a normal course. No significant coronary lumen narrowing was found. Transoesophageal echocardiography confirmed the anomalous origin and course of the aberrant coronary arteries. An exercise test reproduced angina, and ECG changes and myocardial perfusion study showed an anterior reversible defect. In contrast to previous reports, myocardial ischaemia was associated with the septal (intramuscular) course of the left anterior descending coronary artery; there was no other significant coronary artery disease.

Aged↗
PubMed1996

Acute stress markers in humans: response of plasma glucose, cortisol and prolactin to two examinations differing in the anxiety they provoke.

Although the endocrine response to psychological stressors has been extensively studied both in animals and humans, the sensitivity of these variables to the intensity of stress experienced by exposure to psychologically stressful situations has not been studied in humans. In the present work this was assessed by measuring plasma levels of glucose, cortisol and prolactin in female medical students just before taking two examinations clearly differing in the anxiety they provoke. It was found that both examinations increased anxiety just before taking them, but the physiology examination (EPh) caused higher anxiety than the psychology (EPs). Prolactin increased in response to both examinations as compared to the non-stress condition, but its levels were greater in the EPh than in the EPs. Cortisol followed the same pattern as prolactin, but increased only marginally in the EPs. Finally, glycemia rose to the same extent in response to both examinations. A significant positive correlation was found between anxiety and glucose, and between cortisol and prolactin when data from all situations were included. On the basis of these results, it appears that the three variables might be useful as putative markers of stress in humans, although glucose might reflect different underlying psychological processes than cortisol and prolactin. In addition, it was found for the first time that prolactin is able to discriminate between stressful situations of different intensity. The response of these physiological variables to other stressful situations differing both in quantitative and in qualitative terms merits to be studied in further work.

Adult↗
PubMed1995

Retrospective analysis of risk factors and prognosis in non-ventilated patients with nosocomial pneumonia.

Although nosocomial pneumonia in non-ventilated patients continues to be frequent and have high mortality rates, knowledge of the associated risk and prognostic factors is still limited. This retrospective study was designed to analyze epidemiological characteristics, risk and prognostic factors in patients with nosocomial pneumonia admitted to a hospital internal medicine department. Data on epidemiological, clinical and microbiological factors as well as diagnosis and clinical course were obtained from the medical records of 104 patients diagnosed with nosocomial pneumonia, according to Centers for Disease Control criteria, and from 104 control subjects. The incidence of nosocomial pneumonia was 18.8 per 1000 admissions. Risk factors significantly associated with contracting the disease were female sex, hospital stay longer than 14 days, other admission in the previous month and use of antibiotics during the previous six weeks. The most frequent underlying diseases were cardiorespiratory in nature (59.4%). Prognostic factors significantly associated with increased mortality were serious underlying disease, initially critical clinical status, severe and moderate respiratory insufficiency and bilateral radiological signs. More epidemiological data are needed to improve the diagnosis, treatment and prevention of nosocomial pneumonia.

Adrenal Cortex Hormones↗
PubMed1993

Physiologic responses to hyperthermia during epidural anesthesia and combined epidural/enflurane anesthesia in women.

BACKGROUND: During combined epidural/isoflurane anesthesia, the core temperature triggering finger-tip vasoconstriction is approximately 1 degree C less than that triggering redilation. This hysteresis suggests that thermoregulatory responses are not dependent entirely on current thermal status (state-dependence), but may be influenced also by the system's recent thermal history (direction-dependence). Once triggered, the gain and maximum response intensity of many thermoregulatory responses is nearly normal during isoflurane anesthesia. However, it remains unknown whether preserved gain and maximum response intensities are a characteristic paradigm describing thermoregulatory responses to general anesthetics. Also unknown is whether the sweating and pre-capillary vasodilation thresholds are comparably impaired by different volatile anesthetics. Accordingly, the authors tested the hypotheses that, during one minimum alveolar concentration of enflurane anesthesia: (1) there is a direction-dependent hysteresis for sweating; (2) the sweating and active vasodilation thresholds increase approximately 1.2 degrees C, as they do during one minimum alveolar concentration of isoflurane; and (3) the gain and maximum intensity of sweating are well preserved. METHODS: Six female volunteers each were studied on 2 days, once during epidural anesthesia alone and once with combined enflurane (1.7%)/epidural anesthesia. On each study day, core hyperthermia was induced by cutaneous warming restricted to the legs. Warming continued until chest sweating reached maximal values; the volunteers then were cooled gradually until sweating stopped. The core temperature at which the sweating rate departed from baseline values was considered the activation threshold. Gain was expressed as the slope of the sweating rate versus core temperature curve within the range 25-75% of the maximum sweating rate. Hysteresis was evaluated by subtracting the tympanic membrane temperature at which the sweating rate suddenly increased during warming (approximately 25% above baseline values) from that at which sweating precipitously decreased during cooling (approximately 75% of maximum values). RESULTS: The sweating threshold was 1.4 +/- 0.7 degrees C higher during combined enflurane/epidural anesthesia than during epidural anesthesia alone. Maximum intensity was approximately 700 g.m-2.h-1, and the gain approximately 1,300 g.m-2.h-1.degrees C-1 during each treatment. No hysteresis was detected on either study day. CONCLUSIONS: One minimum alveolar concentration of enflurane increased the sweating threshold only slightly more than previously reported for isoflurane. As in previous studies of sweating and vasoconstriction during isoflurane anesthesia, gain and maximum response intensity were well preserved during enflurane anesthesia. An increase in the interthreshold range (temperatures not triggering thermoregulatory responses), with little change in gain and maximum response intensities, appears to be the typical effect of volatile anesthetics. Sweating during enflurane anesthesia appears to be state-dependent and little influenced by the direction of core temperature perturbations.

Adult↗
PubMed1993

Hashimoto's thyroiditis and carcinoma of the thyroid: optimal management.

Several authors have noted a high incidence of thyroid carcinoma in patients with Hashimoto's thyroiditis (HT), and some have even considered HT a premalignant condition. The authors evaluated all patients with surgically proven HT at Beth Israel Medical Center in New York from 1985 through 1990. Of these 48 patients, 8 (17%) had thyroid carcinoma in addition to HT. No statistically significant difference between patients with and without concurrent carcinoma was noted in the percentage of patients with a dominant mass, irregular thyromegaly, compressive symptoms, suspicious fine needle aspiration biopsies (FNABs), or a cold nodule on thyroid scintigraphy. However, patients with neither a positive FNAB nor a cold nodule were much less likely to have carcinoma than patients with one or both of these tests positive (0% vs. 26%, P < or = .05). A management scheme for patients with HT is proposed to adequately and efficiently evaluate and treat patients for concurrent thyroid carcinoma.

Adenoma↗
PubMed1992

The effects of caffeine on the maxillary composition in the newborn rat.

The possible influence of caffeine on maxillary structure was studied. Seventeen pregnant rats at days 9 of gestation were randomly divided into two groups. The dams of group 1 received a 20% protein diet ad libitum throughout the experimental period. The dams of group 2 were pair-fed, with group 1, a 20% protein diet supplemented with 2 mg/100 g body weight (B.W.) caffeine. At birth, pups were mixed within the same group and 8 randomly selected pups were assigned to each dam and continuously fed the respective diet. On day 22, 11 male pups from the control and 12 males from the caffeine group were randomly selected, separated from the dams, and continued to be fed their respective diets. On day 44, a rubber elastic band was inserted between the first and second maxillary right molars. The size of the elastic band was increased throughout the next 5 days. Animals were sacrificed at day 49 and the composition of the maxillas was analyzed. After pulverization, organic and inorganic contents of the bones were measured. Zinc (Zn) and hydroxyproline concentration of the caffeine group showed a significant decrease when compared with those of the controls. However, Ca, P, Mg, and hexosamine concentration showed no difference between the groups. The interdental space measured occlusally and laterally with the visual method, and occlusally in histological sections showed no significant difference between the control and caffeine groups, although variation of the space in the caffeine group was less than in the control group.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Use of ceftriaxone in the treatment of bacterial infections in cirrhotic patients.

Sixty-two episodes of bacterial infection were studied in 51 cirrhotic patients. 2 g of ceftriaxone (active ingredient of Rocephin) were given intravenously once daily for 7-10 days. The infections were pneumonia, bacteremia, spontaneous bacterial peritonitis, urinary infection and others. Good responses were seen in 90% of the cases.

Adult↗
PubMed1987

Potassium disturbances as a cause of metabolic neuromyopathy.

We report two cases of ascending muscular weakness progressing to areflexic quadriplegia caused by severe derangement of potassium homeostasis. The first patient presented with a 17-alpha-hydroxylase deficiency and severe hypokalemia. The second case had primary adrenocortical deficiency (Addison's disease) and extreme hyperkalemia. Complete recovery ensued after correction of the metabolic disorder in both cases. The role of potassium in the pathophysiology of neuromuscular excitation is discussed. We conclude that when neuromyopathy is present, metabolic causes should be considered and the serum potassium determined.

Addison Disease↗
PubMed1979

Pituitary microadenoma: diagnostic studies.

Forty-one women with oligo-menorrhoea and/or galactorrhoea were subjected to hypothalamic pituitary-thyroid testing in an attempt to establish the presence or absence of an underlying pituitary microadenoma. They were divided into two groups in accordance with the serum level of prolactin (PRL): Group I (N = 25, mean +/- SE 17.6 +/- 1.5 ng/ml) and Group II (N = 16, 102.8 +/- 29.7 ng/ml). The dynamic tests performed were a TRH test, a stimulation test with metoclopramide (MCP) and a suppression test with bromocriptine. The results of these tests were compared with those obtained in nine normal women and eleven patients with surgically proved pituitary microadenoma. Radiologically abnormal pituitary fossas were found in ten subjects from Group I and in fourteen from Group II. All patients were euthyroid. A persistently elevated serum TSH in response to TRH was observed in patients of Group II suggesting an hypothalamic abnormality and a progressive decrease in the 120-min use of serum T3 was noted with increasing evidence of the existence of a pituitary tumour. A negative correlation was found between the basal serum PRL and the rise of serum PRL with TRH. Patients from Group II showed a lower PRL response to MCP when compared to Group I and again a negative correlation between basal level of serum PRL and the change after MCP was observed. No clear difference in the 4-h response to bromocriptine was found between the different groups of subjects. In conclusion, none of the three tests analysed permitted us to establish which of the patients had an underlying pituitary microadenoma.

Adenoma↗
PubMed1977

Accuracy of treadmill testing in assessment of direct myocardial revascularization.

Near-maximal treadmill exercise tests (TET) performed at the time of coronary arteriography and bypass graft visualization an average of 13 months after direct myocardial revascularization were analyzed in 217 consecutive patients to assess the accuracy of the TET in predicting completeness of revascularization. TET results were correlated with bypass patency and extent of revascularization. Although conversion of a TET from an abnormal to a normal test or relief of TET-induced angina following surgery is closely correlated with bypass graft patency, the high incidence of normal exercise tests in the presence of residual coronary disease limits their usefulness in the individual postoperative patient in estimating the completeness of revascularization.

Adult↗