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Biomedical subjects

L Blanch

Publications and source records attributed to L Blanch.

At least 55 records · Page 3Linked to original sources
PubMed1995

Cloning of the sulphamidase gene and identification of mutations in Sanfilippo A syndrome.

Sanfilippo A syndrome is one of four recognised Sanfilippo sub-types (A, B, C and D) that result from deficiencies of different enzymes involved in the lysosomal degradation of heparan sulphate; patients suffer from severe neurological disorders. The Sanfilippo syndrome sub-types are also known as mucopolysaccharidosis (MPS) type III (MPS-IIIA, B, C and D), and are part of the large group of lysosomal storage disorders. Each of the MPS-III types is inherited as an autosomal recessive disorder with considerable variation in severity of clinical phenotype. The incidence of Sanfilippo syndrome has been estimated at 1:24,000 in The Netherlands with MPS IIIA (MIM #252900) the most common. MPS-IIIA is the predominant MPS-III in the United Kingdom, and has a similar high incidence to that found in The Netherlands (E. Wraith, personal communication). There is a particularly high incidence of a clinically severe form of MPS-IIIA in the Cayman Islands with a carrier frequency of 0.1 (ref. 4). Due to the mild somatic disease compared to other MPS disorders there is difficulty in diagnosing mild cases of MPS-III, hence Sanfilippo syndrome may be underdiagnosed, especially in patients with mild mental retardation. Here, we report the isolation, sequence and expression of cDNA clones encoding the enzyme sulphamidase (EC 3.10.1.1). In addition, we report the chromosomal localisation of the sulphamidase gene as being 17q25.3. An 11-bp deletion, present in sulphamidase cDNA from two unrelated Sanfilippo A patients, is described.

Amino Acid Sequence↗
PubMed1995

The effect of short-term instillation of a mucolytic agent (mesna) on airway resistance in mechanically ventilated patients.

STUDY OBJECTIVE: To determine whether bolus instillation of a mucolytic agent (mesna) could diminish airway resistance, endotracheal tube resistance, or both in patients mechanically ventilated for acute respiratory failure. DESIGN: Randomized, double-blind, placebo-controlled, crossover trial. SETTING: Medical-surgical ICU of a county hospital covering 350,000 inhabitants. PATIENTS: Twenty sedated and paralyzed patients with an endotracheal tube (ET) in place more than 72 h. INTERVENTIONS: Data were recorded in three steps: (1) basal; (2) 10 min after endotracheal instillation of 3 mL of either saline solution or mesna; and (3) 10 min after instillation of the opposite drug. A 2-h washout period was allowed between data collection. MEASUREMENTS AND RESULTS: We measured tidal volume (VT), inspiratory flow (VI), auto-PEEP, peak pressure (both at airway opening [Pmax.aw] and trachea [Pmax-.tr]) and plateau pressure (Pplat), and we calculated respiratory system compliance (Crs) and the inspiratory resistances of airways+tube (Rmax.aw), airways (Rmax.tr), and ET (Rtube). We found significant differences after the instillation of mesna compared with baseline in the following: airway plus tube resistance (Rmax.aw) (16.9 +/- 7.1 vs 18.9 +/- 7.7 cm H2O); airways resistance (Rmax.tr) (9.8 +/- 6.2 vs 12.0 +/- 6.4 cm H2O), PaO2 (96 +/- 28.5 vs 80 +/- 24.8 mm Hg), PaO2/PAO2 (0.360 +/- 0.152 vs 0.296 +/- 0.127), and PaCO2 (42 +/- 12.9 vs 43 +/- 14.1 mm Hg). We found no changes in compliance, auto-PEEP, and hemodynamics during the study. Instillation of saline solution had no effect on the physiologic variables studied. CONCLUSIONS: In our patients, bolus tracheal instillation of mesna does not improve airway resistance; in fact, mesna instillation induces episodes of bronchospasm that disappear 2 h later.

Aged↗
PubMed1994

Role of bronchoalveolar lavage in mechanically ventilated patients with suspected pneumonia.

To determine the usefulness of samples obtained by bronchoalveolar lavage (BAL) in establishing the diagnosis of ventilator-associated pneumonia, quantitative cultures of BAL and protected specimen brush (PSB) samples obtained via fiberoptic bronchoscope were compared in 42 patients with suspected ventilator-associated pneumonia. Direct examination of BAL fluid was also used to identify cells with intracellular organisms. Ventilator-associated pneumonia was diagnosed in 18 patients; a total of 39 microorganisms were recovered from BAL fluid and 29 from PSB specimens. Cultures of 21 BAL and 23 PSB specimens were sterile. Quantitative BAL and PSB cultures coincided in 76% of cases. Sterile BAL and PSB cultures agreed in 87% of cases. Cultures were completely discordant in only three cases. The sensitivity of BAL for diagnosis of ventilator-associated pneumonia using bacterial counts of > or = 10(4) cfu/ml was 89%, and specificity was 100%. In 14 of the 18 patients with ventilator-associated pneumonia, the percentage of cells containing intracellular organisms in specimens recovered by BAL was 11.6% versus 0.45% in patients without pneumonia (p < 0.05). In the remaining four patients, all of whom had Pseudomonas aeruginosa pneumonia, no intracellular organisms could be detected. Using a cut-off point of > or = 5% of cells with intracellular organisms, the sensitivity and specificity for the early diagnosis of ventilator-associated pneumonia was 67% and 96%, respectively. The results confirm the usefulness of the quantitative BAL culture (with a cut-off at 10(4) cfu/ml) for the diagnosis of ventilator-associated pneumonia. The identification of intracellular organisms in BAL fluid is a good early indicator of pneumonia, but the sensitivity of this technique may be lower for Pseudomonas aeruginosa infections.

Adult↗
PubMed1994

Effect of two tidal volumes on oxygenation and respiratory system mechanics during the early stage of adult respiratory distress syndrome.

PURPOSE: To study the effect of two tidal volumes on gas exchange, lung mechanics, and hemodynamics in 12 patients with acute respiratory distress syndrome (ARDS) within the first 72 hours of mechanical ventilation. METHODS: Tidal volume (VT) was increased by 40% from the initial value at fixed positive end-expiratory pressure (PEEP) and matched minute ventilation by adjusting the respiratory rate (RR) of the ventilator. Initial VT and RR were 592 +/- 42 mL and 19 +/- 1 min-1, respectively. High VT amounted to 825 +/- 54 mL with a RR of 12 +/- 1 min-1. RESULTS: We found that at high VT (1) the index of oxygenation increased from 0.22 +/- 0.03 to 0.32 +/- 0.04 (P < .001) with a parallel decrease in the right to left venous admixture from 0.26 +/- 0.02 to 0.23 +/- 0.02 (P < .001), and in the ratio of physiological dead space to tidal volume (VDS/VT) from 0.53 +/- 0.05 to 0.46 +/- 0.04 (P < .01), without impairment to hemodynamics and (2) respiratory system compliance improved significantly from 34.8 +/- 2.8 mL/cm H2O to 37.2 +/- 2.9 mL/cm H2O (P < .05). In 4 patients, we performed pressure-volume curves on PEEP with the ventilator finding an upward concavity reflecting progressive alveolar recruitment with increasing inflation volume in 3. CONCLUSIONS: High-tidal ventilation in the early stage of ARDS improved gas exchange, suggesting recruitment during the inspiratory phase. However, the benefit of better oxygenation should be weighed against the potential risk of barotrauma induced at high VT.

Adolescent↗
PubMed1994

Relationship between expired capnogram and respiratory system resistance in critically ill patients during total ventilatory support.

To examine the relationship of expired capnograms and respiratory system resistance (Rrs) in intubated critically ill patients, we consecutively studied 41 mechanically ventilated patients to (1) analyze the association between expired CO2 slope and auto-positive end-expiratory pressure (auto-PEEP), between Rrs and auto-PEEP, between Rrs and expired CO2 slope, and between Rrs and arterial minus end-tidal PCO2 gradient (PaCO2-PETCO2 gradient) and (2) to investigate the capacity of the expired CO2 slope and PaCO2-PETCO2 gradient to predict Rrs during mechanical ventilation. Regression analysis found a close correlation between Rrs and expired CO2 slope (r = 0.86; p < 0.001), between Rrs and auto-PEEP (r = 0.75; p < 0.001), and between auto-PEEP and expired CO2 slope (r = 0.74; p < 0.001). Weak correlation was found between Rrs and PaCO2-PETCO2 gradient (r = 0.48; p < 0.01). Prediction interval limits at 95 percent confidence level for Rrs are approximately +/- 7.39 cm H2O/L/s from the predicted value obtained by the regression equation, where Rrs = 11.42 + 2.28 expired CO2 slope. These observations suggest that CO2 elimination in critically ill patients is strongly modulated by lung, airway, endotracheal tube, and ventilator equipment resistances. Although continuous capnogram waveform monitoring at the bedside might be useful to assess Rrs, very accurate predictions could be done only in determinate patients.

Adult↗
PubMed1994

Hemodynamic responses to external counterbalancing of auto-positive end-expiratory pressure in mechanically ventilated patients with chronic obstructive pulmonary disease.

OBJECTIVE: To study the effect of positive end-expiratory pressure (PEEP) on right ventricular hemodynamics and ejection fraction in patients with chronic obstructive pulmonary disease and positive alveolar pressure throughout expiration by dynamic hyperinflation (auto-PEEP). DESIGN: Open, prospective, controlled trial. SETTING: General intensive care unit of a community hospital. PATIENTS: Ten patients sedated and paralyzed with an acute exacerbation of chronic obstructive pulmonary disease undergoing mechanical ventilation. INTERVENTIONS: Insertion of a pulmonary artery catheter modified with a rapid response thermistor and a radial arterial catheter. PEEP was then increased from 0 (PEEP 0) to auto-PEEP level (PEEP = auto-PEEP) and 5 cm H2O above that (PEEP = auto-PEEP +5). MEASUREMENTS: At each level of PEEP, airway pressures, flow and volume, hemodynamic variables (including right ventricular ejection fraction by thermodilution technique), and blood gas analyses were recorded. MAIN RESULTS: The mean auto-PEEP was 6.6 +/- 2.8 cm H2O and the total PEEP reached was 12.2 +/- 2.4 cm H2O. The degree of lung inflation induced by PEEP averaged 145 +/- 87 mL with PEEP = auto-PEEP and 495 +/- 133 mL with PEEP = auto-PEEP + 5. The PEEP = auto-PEEP caused a right ventricular end-diastolic pressure increase, but there was no other significant hemodynamic change. With PEEP = auto-PEEP + 5, there was a significant increase in intravascular pressures; this amount of PEEP reduced cardiac output (from 4.40 +/- 1.38 L/min at PEEP 0 to 4.13 +/- 1.48 L/min; p < .05). The cardiac output reduction induced by PEEP = auto-PEEP + 5 was > 10% in only five cases and this group of patients had significantly lower right ventricular volumes than the group with less cardiac output variation (right ventricular end-diastolic volume: 64 +/- 9 vs. 96 +/- 26 mL/m2; right ventricular end-systolic volume: 38 +/- 6 vs. 65 +/- 21 mL/m2; p < .05) without significant difference in the other variables that were measured. Neither right ventricular ejection fraction nor right ventricle volumes changed as PEEP increased, but there were marked interpatient differences and also pronounced changes in volume between stages in individual patients. CONCLUSIONS: In the study conditions, PEEP application up to values approaching auto-PEEP did not result in the impairment of right ventricular hemodynamics, while higher levels reduced cardiac output in selected patients.

APACHE↗
PubMed1993

Inflation static pressure-volume curves of the total respiratory system determined without any instrumentation other than the mechanical ventilator.

OBJECTIVE: To assess the accuracy of static pressure-volume (PV) curves of the total respiratory system performed with the data directly obtained from the Servo 900 C vs. the data obtained from an external calibrated device. DESIGN: Performance of the PV curve by the method of Levy with simultaneous recording of data obtained from both systems. SETTING: The general ICU of Hospital de Sabadell. PATIENTS: Ten sedated and paralyzed patients ventilated in the control mode for acute respiratory failure were evaluated. INTERVENTIONS AND MEASUREMENTS: Inflation static PV curves were performed by the method of Levy. We simultaneously measured airway pressure and volume by means of calibrated pressure transducer and pneumotachograph and by the internal devices built in the ventilator Siemens Servo 900 C. Statistics were concordance analysis between the two methods and covariance analysis between derived curves. RESULTS: concordance analysis between both methods showed a 95% confidence interval of (+4%, -5%) in volume and (+2.2 cmH2O, -1.7 cmH2O) in pressure. Derived PV curves analyzed by MANOVA showed no significant differences whichever the method used within subject (p = 0.579). CONCLUSION: Inflation static pressure volume curves of the total respiratory system can be accurately performed with the data directly obtained from the Servo Ventilator 900 C without the need of any other external device.

Aged↗
PubMed1993

Pressure support ventilation via face mask in acute respiratory failure in hypercapnic COPD patients.

OBJECTIVE: To test whether non-invasive ventilation via facial mask could reduce the need for tracheal intubation when mechanical ventilation must be initiated in COPD patients. DESIGN: Open prospective interventional study. SETTING: General Intensive Care Service of a County Hospital. PATIENTS: We have studied 12 COPD patients during 14 episodes of acute exacerbation of chronic respiratory failure who failed to improve with intensive medical therapy and showed impairments in severe respiratory acidosis and/or hypercapnic encephalopathy leading their attending physicians to order mechanical ventilation. INTERVENTIONS: In these circumstances, a trial of pressure-support (PS) ventilation (Servo Ventilator 900C) via facial mask Vital Signs Inc.) was performed. The level of pressure support was adjusted to obtain a tidal volume > 400 ml. If the patient deteriorated, tracheal intubation and standard mechanical ventilation were performed. MEASUREMENTS AND RESULTS: Measurements are presented as means +/- SEM. A pressure-support level of 14 +/- 3 cmH2O was used during a period of 8 +/- 4 h. Low levels of external PEEP were used in 4 patients, while it generated excessive leaks in the others. Significant differences (p < 0.05 ANOVA for repeated measures) in data obtained on admission, when patients deteriorated and after pressure support was administered were only observed in PaCO2 (68 +/- 3 versus 92 +/- 3 versus 67 +/- 3 mmHg), arterial pH (7.27 +/- 0.03 versus 7.19 +/- 0.02 versus 7.31 +/- 0.01). SaO2 (60 +/- 4 versus 86 +/- 3 versus 92 +/- 1%) and respiratory rate (35 +/- 2 versus 32 +/- 2 versus 23 +/- 1 breaths.min-1). Three patients needed intubation and one of them died in the ICU. CONCLUSION: Non-invasive ventilation (pressure-support) via face mask may reduce the need for tracheal intubation in the severe hypercapnic failure of COPD patients.

Acute Disease↗
PubMed1992

Effect of tidal volume and PEEP in ethchlorvynol-induced asymmetric lung injury.

We examined the effects of positive end-expiratory pressure (PEEP) and tidal volume on the distribution of ventilation and perfusion in a canine model of asymmetric lung injury. Unilateral right lung edema was established in 10 animals by use of a selective infusion of ethchlorvynol. Five animals were tested in the supine position (horizontal asymmetry) and five in the right decubitus position (vertical asymmetry). Raising PEEP from 5 to 12 cmH2O improved oxygenation despite a redistribution of blood flow toward the damage lung and a consistent decrease in total respiratory system compliance. This improvement paralleled a redistribution of tidal ventilation to the injured lung. This was effected primarily by a fall in the compliance of the noninjured lung due to hyperinflation. The effects of higher tidal volume were additive to those of PEEP. We propose that the major effect of PEEP in inhomogeneous lung injury is to restore tidal ventilation to a population of alveoli recruitable only at high airway pressures.

Animals↗
PubMed1992

[Emphysematous pyelonephritis: a case report and review of the literature].

A case is presented of an E. Coli emphysematous pyelonephritis in a 66 year old female diabetic patient who presented systemic sepsis with positive hemoculture. Diagnosis was obtained thanks to X-ray and the patient had a favorable evolution after left nephrectomy. This is a rare kidney disease (123 described cases) which evolves with necrosis of renal parenchyma and gas formation which frequently expands to the perirenal space and/or to the collector system. It presents a high mortality which can decrease according to the promptness of diagnosis based on X-ray. Thirty eight literature cases of the last decade are reviewed evaluating the efficiency of image diagnostic measures and surgical performance.

Aged↗