Biomedical subjects

S Nava

Publications and source records attributed to S Nava.

At least 19 recordsLinked to original sources

PubMed1995

Elevated static compliance of the total respiratory system: early predictor of weaning unsuccess in severed COPD patients mechanically ventilated.

OBJECTIVE: To assess in a group of COPD patients mechanically ventilated for an episode of acute respiratory failure the respiratory mechanics with a simple and non invasive method at the bedside in order to evaluate if these parameters may be predictive of weaning failure or success. DESIGN: A prospective study. SETTING: Intensive care and intermediate intensive care units. PATIENTS: 23 COPD patients ventilated for acute respiratory failure and studied within 24 hours from intubation. METHODS: Using end-expiratory and end-inspiratory airway occlusion technique, we measured PEEPi, static compliance of the respiratory system (Crs, st) maximum respiratory resistance (Rrsmax) and minimum respiratory resistance (Rrsmin). MEASUREMENTS AND RESULTS: The weaned group (A) and the not weaned group (B) were not different regarding to static PEEPi (group A 8.5 +/- 4.0 vs group B 8.9 +/- 2.6 cmH2O), TO Rrsmax (22.4 +/- 5.3 versus 22.2 +/- 9.0 cmH2O/1/s) and to Rrsmin (17.6 +/- 5.5 versus 17.9 +/- 8.0 cmH2O/1/s), while a significant difference (p < 0.001) has been found in Cst, rs (62.7 +/- 17.% versus 111.6 +/- 18.0 ml/cm H2O). The threshold value of 88.5 ml/cmH2O was identified by discriminant analysis and provided the best separation between the two groups, with a sensitivity of 0.85 and a specificity of 0.87. CONCLUSION: Cst, rs measured non invasively in the first 24 h from intubation, provided a good separation between the patients who were successfully weaned and those who failed.

Acute Disease↗

PubMed1995

Quantitative analysis of IgA-subclass antibodies against tetanus toxoid.

Sera were analysed for levels of IgA- and IgG-class and IgA-subclass antibodies against tetanus toxoid and synthesized, tetanus-toxoid, beta-chain peptides. Forty-five peptides, deduced from the amino-acid sequence of the tetanus-toxoid beta-chain, were synthesized, in order to analyse epitope-binding of antibodies. Monoclonal, human, anti-tetanus antibodies were used to evaluate the synthesized peptides. Five synthesized peptides, bound by high, medium or low levels of IgA antibodies, were selected for the quantification of IgA1 and IgA2 antibodies. A set of chimeric, IgA-subclass antibodies with NP-specificity were used to quantify the antigen-specific IgA-subclass antibodies in a novel assay. Antibodies against the synthesized peptides were predominantly of IgA1 subclass.

Adult↗

PubMed1995

Non-invasive mechanical ventilation in acute respiratory failure due to chronic obstructive pulmonary disease: correlates for success.

BACKGROUND: Non-invasive mechanical ventilation is increasingly used in the treatment of acute respiratory failure in patients with chronic obstructive pulmonary disease (COPD). The aim of this study was to identify simple parameters to predict the success of this technique. METHODS: Fifty nine episodes of acute respiratory failure in 47 patients with COPD treated with non-invasive mechanical ventilation were analysed, considering each one as successful (78%) or unsuccessful (22%) according to survival and to the need for endotracheal intubation. RESULTS: Pneumonia was the cause of acute respiratory failure in 38% of the unsuccessful episodes but only in 9% of the successful ones. Success with non-invasive mechanical ventilation was associated with less severely abnormal baseline clinical and functional parameters, and with less severe levels of acidosis assessed during an initial trial of non-invasive mechanical ventilation. CONCLUSIONS: The severity of the episode of acute respiratory failure as assessed by clinical and functional compromise, and the level of acidosis and hypercapnia during an initial trial of non-invasive mechanical ventilation, have an influence on the likelihood for success with non-invasive mechanical ventilation and may prove to be useful in deciding whether to continue with this treatment.

Aged↗

PubMed1995

Hemidiaphragm dysfunction due to megacolon: functional recovery after colectomy.

We describe an uncommon case of hemidiaphragm dysfunction in a man with megacolon. The patient complained of exertional dyspnoea associated with a restrictive ventilatory impairment, a reduction in respiratory muscle force, and a left hemidiaphragm elevation on roentgenogram. During maximal inspiratory manoeuvre, the electromyograph (EMG) showed an abnormal pattern in the time of recruitment of the left hemidiaphragm, associated with a rapid decline in force. After abdominal surgery (total colectomy) a significant improvement in lung volumes was observed, together with a resolution of dyspnoea. Respiratory muscle force returned to normal values with a normal EMG, whilst the elevation of the left hemidiaphragm at radiography was still present, though to a lesser extent.

Colectomy↗

PubMed1994

The role of radiotherapy in the treatment of stage III non-small cell lung cancer: a survey of clinical practices in Lombardy, Italy, by the Airo*-Lombardia Cooperative Group.

AIMS AND BACKGROUND: The role of radiotherapy in the treatment of stage III non-small cell lung cancer is controversial. The aim of this survey was to investigate the use of this modality in current clinical practice in Lombardy, a highly industrialized region of northern Italy. METHODS: A questionnaire was sent to all 13 radiotherapy centers in Lombardy, covering statistical, clinical, technical and strategical aspects, and the responses were analyzed. RESULTS: A wide range of attitudes was observed among participating radiation oncologists; the percentage of cases treated with curative intent varied largely between centers (4-100%), as did the proportion of patients given to radiation only rather than combined modality treatment (5-100% vs 0-90%). CONCLUSIONS: An urgent need exists for better cooperation between all clinicians involved in lung cancer treatment, pursuing the goals of a more uniform clinical practice and a more aggressive clinical research attitude.

Carcinoma, Non-Small-Cell Lung↗

PubMed1994

Acute effect of corticosteroids on respiratory mechanics in mechanically ventilated patients with chronic airflow obstruction and acute respiratory failure.

We assessed the short-term effect of steroids on respiratory mechanics in eight mechanically ventilated patients with chronic airflow obstruction (CAO) and hypercapnic respiratory failure. Airflow (V), airway pressure (Paw), and changes in pulmonary volume were measured using a conventional ventilator. End-expiratory and end-inspiratory airway occlusions were performed to assess intrinsic PEEP (PEEPi), static compliance of total respiratory system (Cstrs), maximum inspiratory resistance (Rrsmax), and minimum inspiratory resistance (Rrsmin). These parameters were recorded at control, 30 min after saline, and 90 min after steroid (methylprednisolone 0.8 mg/kg intravenous) administration. No significant changes were found in respiratory mechanics after administration of saline. Steroids induced a significant decrease (p < 0.01) in inspiratory resistance (Rrsmax from 20.3 +/- 8.6 cm H2O/L/s (control) to 15.3 +/- 6.1 (90 min) and Rrsmin from 16.2 +/- 8.0 (control) to 11.9 +/- 6.5 (90 min), with no significant reduction in Paw and Cstrs. The PEEPi, reflecting pulmonary dynamic hyperinflation, was also significantly reduced (-16% from control). We conclude that in mechanically ventilated CAO patients, steroids may be useful in improving respiratory mechanics and therefore in providing better conditions for weaning from mechanical ventilation.

Female↗

PubMed1994

Survival and prediction of successful ventilator weaning in COPD patients requiring mechanical ventilation for more than 21 days.

We studied survival and failure or success of weaning from mechanical ventilation (MV) in 42 consecutive chronic obstructive pulmonary disease (COPD) patients requiring prolonged MV (more than 21 days) after an episode of acute respiratory failure requiring admission to our Intermediate Intensive Care Unit (IICU). Parameters including arterial blood gases, pulmonary function tests, respiratory muscle force, neuromuscular drive, and nutritional status were recorded during a phase of clinical stability, in order to identify the features related to survival and weaning. All the patients were submitted to a comprehensive rehabilitation programme. Successful weaning from MV was defined as complete respiratory autonomy for at least 48 h. Twenty three patients were successfully weaned from MV after an average period of 44 days (Group A), requiring no further MV during their stay in hospital, whilst the remaining 19 patients were not able to be disconnected from the ventilator (Group B). The discriminant analysis showed that weaning from MV was significantly associated with arterial carbon dioxide tension (PaCO2), neuromuscular drive (P0.1), maximal inspiratory pressure (MIP), arterial oxygen tension (PaO2), the ratio of respiratory frequency to tidal volume (f/VT) and the serum protein level. Other pulmonary function tests (forced expiratory volume in one second (FEV1), FEV1/forced vital capacity (FVC), anthropometric data, nutritional status, number of pulmonary exacerbations during MV and evidence of cor pulmonale, were similar in the two groups. The discriminant equation considering PaCO2 and MIP could separate the two groups with an accuracy of 84%. The overall survival at 2 yrs was 40%; in Group B it was significantly lower than in Group A (22 vs 68%). Most of the deaths occurred within the first 120 days after intubation.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1994

[Primary antiphospholipid syndrome and cardiac involvement. Description of a clinical case of right atrial thrombosis].

Antiphospholipid syndrome is a well-defined clinical and serological entity characterized by venous and arterial thrombosis, recurrent abortion and thrombocytopenia. The immunological feature shows the presence of anticardiolipin antibodies and lupus anticoagulant. Cardiac involvement includes pericardial effusion, myocardial dysfunction, valvular disease, coronary artery occlusion. The literature reports only a few cases of intracardiac thrombosis associated with primary antiphospholipid syndrome. Here we describe a case of a 54 year-old woman with thrombocytopenia and history of recurrent abortions. When she was 51 she presented a left deep iliac venous thrombosis, followed by recurrent pulmonary embolism; a caval filter was placed in the inferior vena cava. Transthoracic and transoesophageal echocardiogram showed 3 masses in the right atrium: the first one was connected with the atrial wall, hyperechogenic and extending to the right ventricle in diastole: th second was connected with the interatrial septum and less echogenic; the third was in connection with septum-tricuspid valve junction and it was floating in the atrium. The immunological feature showed the presence of lupus anticoagulant and antiphospholipid antibodies; the histological examination of the masses, surgically removed, proved they were thrombi coated by endothelial cells. The case reported is very uncommon and offers the opportunity to emphasize the difficulty of diagnostic differentiation of intracardiac masses using echocardiographic imaging: thrombotic masses may present similar characteristics of seat, morphology and echogenicity of other cardiac masses. For these reasons it can be useful to look for antiphospholipid antibodies and lupus anticoagulant in such clinical conditions.

Antiphospholipid Syndrome↗

PubMed1994

Ventilatory techniques during weaning.

Ventilatory techniques are only a part of the weaning process, that also includes medical therapy, physiokinesitherapy, nutrition, psychological support and nursing. Traditional ventilatory techniques used in weaning are: T-piece trials (alternated with assist-control ventilation (ACV)), pressure support ventilation (PSV), intermittent mandatory ventilation (IMV) and continuous positive airway pressure (CPAP) ventilation. None of these techniques has been demonstrated to be better than the others, and the physician must be prepared--to try alternate strategies according to the kind of patient. Noninvasive mechanical ventilation (NIMV) can be successfully used in weaning from invasive mechanical ventilation. Furthermore, NIMV by nasal or facial mask has been successfully used in the treatment of acute respiratory failure (ARF) due to various pathologies. In these cases, the weaning trial has an immediate beginning, since noninvasive ventilation is performed alternatively with spontaneous breathing after the early phase of ARF.

Humans↗

PubMed1994

Weaning and outcome from mechanical ventilation.

Weaning means the ability of a patient to breath spontaneously after mechanical ventilation. In chronic obstructive pulmonary disease (COPD) patients, inability to tolerate discontinuation of mechanical ventilation is reported to have an incidence of 25-60%. It is, therefore, important to employ simple parameters able to predict weaning success, since, in the case of failure, the validation of predictive indices of weaning may also contribute to the decision of whether or not these patients should eventually enter a programme of home ventilation. Among other indices employed, respiratory frequency/tidal volume (f/VT) ratio, compliance, rate, oxygenation and pressure (CROP) index, mouth occlusion pressure (P0.1) and static compliance of the respiratory system have been shown to be quite accurate. The survival at one year of these patients requiring mechanical ventilation ranges 34-49%. Indeed, there is a particular subset of COPD patients in whom mechanical ventilation is prolonged due to the severity of their pathology. We studied 42 of these patients requiring mechanical ventilation for more than 21 days, to assess with simple parameters (arterial blood gases, pulmonary function tests, respiratory muscle force, P0.1, nutritional status) their potential for weaning and their survival at 2 yrs. Using discriminant analysis, and employing an equation comprising maximal inspiratory pressure (MIP) and arterial carbon dioxide tension (PaCO2), we were able to predict the patients able or unable to be weaned with an accuracy of almost 85%.(ABSTRACT TRUNCATED AT 250 WORDS)

Humans↗

PubMed1994

[Infectious endocarditis following artificial insemination. A clinical case report and review of the literature].

We describe a case of infective endocarditis in a 33 year old patient, with mitral valve prolapse (MVP), who underwent nine attempts of artificial insemination with semen by donor. Several blood cultures demonstrated the presence of Enterococcus faecalis; the same agent was identified in some vaginal cultures. Despite antibiotic therapy, infective endocarditis was complicated by severe mitral regurgitation, followed by the rupture of a chorda tendinea. The patient underwent cardiac surgery: valvuloplasty of posterior mitral cusp, chordae tendineae in Goretex and anulus reinforcement with autologous pericardium. MVP is the most common heart disease associated with infective endocarditis in non-drug addict patients (32-54%). The review of the literature did not show any other case of infective endocarditis after artificial insemination procedures. Because of the large spread of these procedures, we think antibiotic prophylaxis of infective endocarditis should be considered in patients with MVP.

Adult↗

PubMed1994

Noninvasive mechanical ventilation in the treatment of acute respiratory failure due to infectious complications of lung transplantation.

Patients that have undergone lung and heart-lung transplantation may contract severe respiratory infections, often leading to acute respiratory failure requiring mechanical ventilation. Endotracheal intubation may induce infectious complications of the respiratory tract, which can be avoided by noninvasive modes of ventilation. We describe the use of noninvasive modes of ventilation in three cases of acute respiratory failure induced by infectious complication of lung and heart-lung transplantation. In two cases endotracheal intubation was avoided and treatment was successful.

Acute Disease↗

PubMed1994

[Nasal pressure support ventilation (NPSV) in a case of Pneumocystis carinii pneumonia in single-lung transplantation].

In patients who underwent lung transplantation one of the primary determinants of patient survival is infection. Contributing factors in the development of pneumonia include immunosuppression and alterations in the natural lung defense mechanism induced by transplantation. We describe a case of a Pneumocystis carinii pneumonia occurring in the recipient of single lung transplantation for interstitial lung disease four months after surgery. The patient developed severe acute respiratory failure (ARF) requiring mechanical ventilation. Because of the increased infectious risk, tracheal intubation was avoided and pressure support ventilation was performed by the nasal route (NPSV) with PEEP (PS: 16 cm H2O PEEP: 8 cm H2O). NPSV and PEEP were applied 20-22 hours/day in the first 4 days, thereafter 2 to 6 hours 3 times a day, together with medical therapy. This treatment was performed for 15 days. This mode of ventilation was well tolerated and was successful. We conclude that NPSV may be useful in the treatment of ARF in patients with lung transplantation, particularly to avoid invasive mechanical ventilation related infectious complications.

Humans↗

PubMed1993

Non-invasive modalities of positive pressure ventilation improve the outcome of acute exacerbations in COLD patients.

OBJECTIVE: 1) To compare the clinical usefulness of both non-invasive pressure support ventilation (NPSV) and non-invasive intermittent positive pressure ventilation in assist-control (A/C) mode (NIPPV) in chronic obstructive lung disease (COLD) patients with acute hypercapnic respiratory failure: 2) to compare retrospectively the usefulness of non-invasive mechanical ventilation (NMV) with standard medical therapy alone. DESIGN: Prospective randomized retrospective study. SETTING: 2 Respiratory intermediate intensive units. PATIENTS: 29 COLD patients (age: 62 +/- 8 years) with chronic respiratory failure were hospitalized in a department for rehabilitation during acute relapses of their disease. They were transferred to our intermediate intensive care unit (IICU) and submitted randomly to either NPSV (16 patients) or NIPPV (13 patients). MEASUREMENTS AND RESULTS: Blood gas analysis, dynamic flows, clinical variables, success rate, time of ventilation, side effects and subjective score of compliance to therapy. Therapy was considered successful when endotracheal intubation was avoided and patients were returned to their condition prior to exacerbation. No statistically significant difference was found between NPSV and NIPPV in success rate (NPSV 87.5%; NIPPV 77%) or in time of ventilation (NPSV: 69 +/- 49; NIPPV: 57 +/- 49 h). A better compliance to non-invasive mechanical ventilation (NMV) was found in NPSV patients than in NIPPV patients; side effects were observed less frequently in the NPSV group. Comparison of the success rate of NMV was retrospectively performed with 35 control COLD patients with chronic respiratory insufficiency who had undergone an acute relapse of their disease in the 2 years preceding the institution of the IICU and had been treated with oxygen and medical therapy alone. Patients submitted to NMV showed a greater success rate than control (82 versus 54%) after a period of ventilation ranging from 4-216 h. CONCLUSION: Non-invasive mechanical ventilation performed either by NPSV or NIPPV may improve the outcome of acute exacerbations of COLD, as compared to medical therapy alone. NPSV seems to be more acceptable to patients in comparison with NIPPV.

Acute Disease↗

PubMed1993

Total cavopulmonary direct anastomosis: a logical approach in selected patients.

A 2.5-year-old boy with a diagnosis of situs solitus, tricuspid atresia, anatomically corrected malposition of the great arteries (S,D,L), left juxtaposition of atrial appendages, and pulmonary stenosis underwent successful total cava-to-pulmonary connection by means of a superior vena cava-to-pulmonary artery end-to-side anastomosis associated with an inferior vena cava-to-pulmonary artery direct anastomosis. Anatomic features and surgical technique are described.

Abnormalities, Multiple↗

PubMed1993

Methods for the analysis of cellular kinetics in PHA-stimulated blood lymphocytes using BrdU incorporation. A comparative study.

The cellular cycle (cc) span was measured by using differential sister-chromatid staining (DSCS) and applying the following methods: cellular cycle time (cct) according to the graphic method of Dutrillaux and Fosse (G-cct); the analytical equation (A-cct) proposed in the present paper, and the average generation time (AGT) suggested by Ivett and Tice. The mean values obtained by the three methods were 12.5, 12.7, and 19.5 h, respectively. A-cct is the more precise method, since the equation of the analytical procedure allows the utilization of numerical data, and when the graphical method is used, the values plotted in a graph may vary according to the employed scale. Cct is the choice over AGT because the first evaluates actively dividing cells and only considers those at M2 or M3. It will be useful to study cell proliferation kinetics in genetic pathological conditions and to investigate with accuracy the effect of cytostatic and cytotoxic drugs.

Adolescent↗

PubMed1993

Haemodynamic effects of pressure support and PEEP ventilation by nasal route in patients with stable chronic obstructive pulmonary disease.

BACKGROUND: Intermittent positive pressure ventilation applied through a nasal mask has been shown to be useful in the treatment of chronic respiratory insufficiency. Pressure support ventilation is an assisted mode of ventilation which is being increasingly used. Invasive ventilation with intermittent positive pressure, with or without positive end expiratory pressure (PEEP), has been found to affect venous return and cardiac output. This study evaluated the acute haemodynamic support ventilation by nasal mask, with and without the application of PEEP, in patients with severe stable chronic obstructive pulmonary disease and hypercapnia. METHODS: Nine patients with severe stable chronic obstructive pulmonary disease performed sessions lasting 10 minutes each of pressure support ventilation by nasal mask while undergoing right heart catheterisation for clinical evaluation. In random order, four sessions of nasal pressure support ventilation were applied consisting of: (1) peak inspiratory pressure (PIP) 10 cm H2O, PEEP 0 cm H2O; (2) PIP 10 cm H2O, PEEP 5 cm H2O; (3) PIP 20 cm H2O, PEEP 0 cm H2O; (4) PIP 20 cm H2O, PEEP 5 cm H2O. RESULTS: Significant increases in arterial oxygen tension (Pao2) and saturation (Sao2) and significant reductions in arterial carbon dioxide tension (PaCO2) and changes in pH were observed with a PIP of 20 cm H2O. Statistical analysis showed that the addition of 5 cm H2O PEEP did not further improve arterial blood gas tensions. Comparison of baseline values with measurements performed after 10 minutes of each session of ventilation showed that all modes of ventilation except PIP 10 cm H2O without PEEP induced a small but significant increase in pulmonary capillary wedge pressure. In comparison with baseline values, a significant decrease in cardiac output and oxygen delivery was induced only by the addition of PEEP to both levels of PIP. CONCLUSIONS: In patients with severe stable chronic obstructive pulmonary disease and hypercapnia, pressure support ventilation with the addition of PEEP delivered by nasal mask may have short term acute haemodynamic effects in reducing oxygen delivery in spite of adequate levels of SaO2.

Aged↗

PubMed1993

Recruitment of some respiratory muscles during three maximal inspiratory manoeuvres.

BACKGROUND: A study was undertaken to determine the level of recruitment of the muscles used in the generation of respiratory muscle force, and to ascertain whether maximal diaphragmatic force and maximal inspiratory muscle force need to be measured by separate tests. The level of activity of three inspiratory muscles and one expiratory muscle during three maximal respiratory manoeuvres was studied: (1) maximal inspiration against a closed airway (Muller manoeuvre or maximal inspiratory pressure (MIP)); (2) maximal inspired manoeuvre followed by a maximal expiratory effort (combined manoeuvre); and (3) maximal inspiratory sniff through the nose (sniff manoeuvre). METHODS: All the manoeuvres were performed from functional residual capacity. The gastric (PGA) and oesophageal (POES) pressures and their difference, transdiaphragmatic pressure (PDI), and the integrated EMG activity of the diaphragm (EDI), the sternomastoid (ESTR), the intercostal parasternals (ERIC), and the rectus abdominis muscles (ERA) were recorded. RESULTS: Mean (SD) PDI values for the Muller, combined, and sniff manoeuvres were: 127.6 (19.4), 162.7 (22.2), and 136.6 (24.8) cm H2O, respectively. The pattern of rib cage muscle recruitment (POES/PDI) was similar for the Muller and sniff manoeuvres (88% and 80% respectively), and was 58% in the combined manoeuvre, confirming data previously reported in the literature. Peak EDI amplitude was greater during the sniff manoeuvre in all subjects (100%) than during the combined (88.1%) and Muller (61.1%) manoeuvres. ESTR and EIC were more active in the Muller and the sniff manoeuvres. The contribution of the expiratory muscle (ERA) to the three manoeuvres was 100% in the combined, 26.1% for the sniff, and 11.5% for the Muller manoeuvre. CONCLUSIONS: Each of these three manoeuvres results in different mechanisms of inspiratory and expiratory muscle activation and the intrathoracic and intra-abdominal pressures generated are a reflection of the interaction between the various muscle groups. The Muller and sniff manoeuvres reflect mainly the force of the inspiratory muscles and the combined manoeuvre that of the diaphragm.

Adult↗