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Biomedical subjects

G C Montiel

Publications and source records attributed to G C Montiel.

11 recordsLinked to original sources
PubMed1999

Evaluation of bronchodilator response in patients with airway obstruction.

The aim of this study was to define the most useful index of expressing bronchodilator response and to distinguish between asthma and COPD. A prospective study was carried out of bronchodilator response in 142 asthmatics and 58 COPD patients in a university hospital. Reversibility was expressed as: 1. absolute change (delta abs); 2. % of initial (delta %init); 3. % of predicted (delta %pred) and 4. % of maximum possible response (delta %max). Dependence on forced expirations volume in 1 sec (FEV1) as % of predicted and sensitivity and specificity for diagnosis of asthma were established. A relationship between delta abs and initial FEV1 was not found in asthma (delta abs vs. % initial FEV1. r = 0.07) or COPD (r = 0.02). delta %pred did not show a correlation in asthma (r = 0.10) or COPD (r = 0.06). delta %init was dependent on the baseline value in asthma (r = 0.38, P < or = 0.001) but not in COPD (r = 0.18, P = n.s.). delta max was dependent in both. The combination of best sensitivity and specificity to separate asthma and COPD was obtained with delta abs (70.4 or 70.6%). The worst specificity for asthma diagnosis was obtained with delta %init (50%). The best likelihood ratios were obtained with delta abs and delta %pred and the worst likelihood ratio with delta %init. delta %init is not recommended as an index for differential diagnosis between asthma and COPD; 2) delta %init overscores bronchodilator response in patients with low FEV1. The independence of each bronchodilator response index should be verified in clinical trials for each selected sample.

Aged↗
PubMed1998

[Non-invasive mechanical ventilation as treatment for severe pneumonia in an HIV positive patient].

A 27 year-old HIV+ patient was admitted to the hospital for probable Pneumocystis carinii pneumonia (PCP). He was severely dyspneic, with respiratory rate of 44 x min and accessory respiratory muscle contraction. The alveolar-arterial quotient was 0.35. Ventilation by BiPAP was applied during 12 hours. After BiPAP a/AO2 was O.42, with amelioration of dyspnea, decrease of respiratory rate (25 x min) and without using of accessory respiratory muscles. No complications occurred. At the end of hospital stay a/AO2 was 0.68. CPAP application but not BiPAP has been reported in PCP. Our patient showed evident improvement after BiPAP, suggesting that this method of ventilation is useful and should be incorporated to the routine management of these patients.

AIDS-Related Opportunistic Infections↗
PubMed1996

Bilateral diaphragmatic paralysis after mediastinal radiotherapy.

A 35-year-old man presented bilateral phrenic paralysis 7 months after radio-therapy for treatment of Hodgkin's lymphoma. Diaphragmatic dysfunction appeared after complete lymphoma remission and 4 months after chemotherapy discontinuation. There were no other potential causes. Idiopathic diaphragmatic paralysis was unlikely because it is usually unilateral. Radiation-induced neuropathy is well documented in other nerves as the brachial plexus. The timing, the applied dose and the location of the nerve within the radiation field are suggestive of radiation-induced phrenic nerve damage. Partial recovery was achieved after 4 years' follow-up.

Adult↗
PubMed1994

[Functional obstruction of the upper airway].

Laryngeal wheezing caused by emotional stress is usually confused with that caused by bronchospasm and diagnosed as asthma, a well known emotionally influenced entity. Therefore, it is treated with bronchodilators, including corticosteroids, frequently resulting in a iatrogenic Cushing's syndrome. This case report concerns a patient initially considered to have bronchial asthma. Physiological and endoscopic studies allowed us to exclude this disease, as well as any organic obstruction of the upper and lower airway. Flow-volume curve showed that the tidal volume (VT) loop was displaced towards RV during the crisis and the expiratory flow of the VT reached the envelope of the maximal expiratory flow (Fig. 1). Direct larynx observation during fiberoptic bronchoscopy showed not only expiratory but also inspiratory vocal cords adduction. A diagnosis of emotional laryngeal wheezing was made. Excluding asthma, bronchodilators were progressively discontinued. She started to receive alprazolam and psychotherapy and during one year of follow-up she remained symptomless. Two mechanisms may be present in our patient: partial inspiratory adduction of vocal cords and breathing at low lung volume. Despite reported dissimilarities between these two mechanisms both seem to have a similar emotional origin.

Airway Obstruction↗
PubMed1994

[Response to bronchodilators among patients with bronchial asthma].

The response to bronchodilators was evaluated in 295 spirometric studies performed in 82 patients with asthma (defined according to ATS criteria, with at least one previous basal test with 20% of change in FEV1 compared with the present test). The response to bronchodilators (Bd) was measured fifteen minutes after the inhalation of salbutamol 200 mcg by metered dose inhaler and in the absence of Bd inhalation in the previous six hours. Sixty-eight spirometries (23%) were classified as with no response to Bd (NR) (absolute delta FEVI[delta abs] < 200 ml, delta FEV1 in percentage of initial FEVI[delta%] < 15%, delta FVC in percentage of the initial [delta FVC] < 15% and delta FEF 25-75% in percentage of the initial [delta FEF] < 25%). Only 23% (n = 16) of them showed an initial FEVI greater than 80% of predicted. In this group 4 tests (5% of NR, 1.3% of the whole) showed delta abs > 150 ml and 1 (1.5% of NR, 0.3% of whole) delta% > 12%. Thirty six percent of the whole population (n = 109) would have been classified as NR taking as unique criterion delta VEF1% < 15%, 24 of which (8% of whole population) showed delta VEF1 abs > 200 ml (initial FEVI 2.48 +/- 0.60 l) (Table 3). On the other hand, 94 spirometries (31% of the whole) would have been classified as NR taking as unique criterion delta abs < 200 ml. twelve of which (4% of the whole) showed delta% > 15% (initial FEVI 0.81 +/- 0.171) (Table 2).(ABSTRACT TRUNCATED AT 250 WORDS)

Albuterol↗
PubMed1994

[Central alveolar hypoventilation with cor pulmonale: successful treatment by non-invasive intermittent positive pressure ventilation].

A 62 year-old woman with a bilateral carotid body paraganglioma presented, 2 years after the removal of the right one, with signs of right-heart failure. Hypoxemia, hypercapnia, polycythemia and pulmonary hypertension with normal ventilatory capacity were found. Central alveolar hypoventilation was diagnosed on the basis of absence of ventilatory response and sensation of provoked hypercapnia, prolonged breath-holding time and correction of hypercapnia by voluntary ventilation. Progesterone (200 mg/d during 3 weeks) or naloxone did not improve either arterial blood gases (ABG) or the P 0.1/PCO2 curve. Hypoxemia and hypercapnia were not corrected during metabolic acidosis provoked by acetazolamide (250 mg/d). Nasal CPAP did not control hypoventilation periods. Mechanical ventilation was initiated with negative pressure (NPV) through a poncho. The patient presented severe discomfort with NPV and obstructive apneas were verified during it. She refused to continue NPV. Mechanical ventilation was initiated with positive intermittent pressure (IPPV) through a nasal mask. The patient had excellent tolerance to the procedure. SpO2 during IPPV was always higher than 95%. During sleep induction (under IPPV), respiration in phase with the ventilator 1: 1 was observed; instead, during consolidated sleep there was a complete dependence of the ventilator with apnea for over 2 min when IPPV was interrupted (Fig. 1). After 2 months of treatment, a relief of right ventricular failure occurred and hematocrit fell to 39%. There was an improvement of day-time ABG (Table I). The P. 0.1/PaCO2 curve 3 months after IPPV was the same as the previous one (Fig. 2). The patient has been for 18 months on home ventilation.(ABSTRACT TRUNCATED AT 250 WORDS)

Female↗
PubMed1994

[Treatment of respiratory insufficiency secondary to vocal cord bilateral paralysis with continuous positive pressure].

Vocal cord paralysis can produce extrathoracic airway obstruction with severe respiratory failure, post-surgical traumatism being the most frequent. Definitive treatment can require aritenoidectomy. For emergency treatment tracheal intubation of tracheotomy are frequently needed. We report a patient with acute post-surgical upper airway obstruction successfully treated with CPAP application through nasal mask. A 29 year-old female showed stridor and retraction of the supraclavicular, intercostal and epigastric region following an uncomplicated tracheal extubation immediately after surgery (radical thyroidectomy with nodal dissection). Pulsosaturometry showed O2 desaturation despite high flow O2 administration. She received intravenous steroids and O2 through intermittent positive pressure by nasal mask (manual resuscitator) increasing SpO2 to 90%. Laringoscopy showed both vocal cords fixed at medium line. CPAP through a nasal mask was initiated with a 5 cm H2O pressure and high FIO2. Immediately afterwards, dyspnea, stridor, supraclavicular retraction and respiratory accessory muscles use disappeared. Heart rate decreased (120 to 92 x min.) and SpO2 increased to 99%. Arterial blood gases did not show hypercapnia. Dyspnea and physical signs of upper airway obstruction appeared immediately after interrupting CPAP application, with a marked decrease in SpO2. So the mask was reinstalled keeping the same pressure level during 18 hs. The procedure was well tolerated. There were no local or hemodynamic complications. CPAP was progressively discontinued.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

[Error factors in spirometry].

Spirometry is the more frequently used method to estimate pulmonary function in the clinical laboratory. It is important to comply with technical requisites to approximate the real values sought as well as adequate interpretation of results. Recommendations are made to establish: 1--quality control 2--define abnormality 3--classify the change from normal and its degree 4--define reversibility. In relation to quality control several criteria are pointed out such as end of the test, back-extrapolation and extrapolated volume in order to delineate most common errors. Daily calibration is advised. Inspection of graphical records of the test is mandatory. The limitations to the common use of 80% of predicted values to establish abnormality is stressed. The reasons for employing 95% confidence limits are detailed. It is important to select the reference values equation (in view of the differences in predicted values). It is advisable to validate the selection with local population normal values. In relation to the definition of the defect as restrictive or obstructive, the limitations of vital capacity (VC) to establish restriction, when obstruction is also present, are defined. Also the limitations of maximal mid-expiratory flow 25-75 (FMF 25-75) as an isolated marker of obstruction. Finally the qualities of forced expiratory volume in 1 sec (VEF1) and the difficulties with other indicators (CVF, FMF 25-75, VEF1/CVF) to estimate reversibility after bronchodilators are evaluated. The value of different methods used to define reversibility (% of change in initial value, absolute change or % of predicted), is commented. Clinical spirometric studies in order to be valuable should be performed with the same technical rigour as any other more complex studies.

Adolescent↗
PubMed1993

Bilateral carotid body paraganglioma and central alveolar hypoventilation.

A 62-year-old woman with a bilateral carotid body paraganglioma presented, 2 years after the removal of the right one, with signs of right-heart failure. Hypoxemia, hypercapnia, polycythemia and pulmonary hypertension with normal ventilatory capacity were found. Central alveolar hypoventilation was diagnosed on the basis of absence of ventilatory response and sensation to provoked hypercapnia, prolonged breath-holding time and correction of hypercapnia by voluntary hyperventilation.

Carotid Body Tumor↗
PubMed1991

[Diaphragmatic reserve strength in obese patients].

Nine obese patients (OB) and seven normal subjects (N) were studied in order to determine diaphragmatic strength reserve, measured in terms of diaphragm Tension/Time Index (TTdi). This index was measured with the patients awake and during the obstructive apnea (OA) episodes. TTdi was 2.7 times superior in the OB (p < 0.0005) and was related with a lower Pdi Max (102 vs 202 cm H2O; p < 0.005) and with a higher Pdi (9 vs 6 cm H2O; p < 0.05). During OA the TTdi was higher than the threshold value to develop diaphragmatic fatigue (0.15-0.20) in three patients. This value was not exceeded in one patient because of striking paradoxical diaphragmatic movements. As for anthropometric data, DPI% range was higher and wider in OB (Table 1). The pCO2 in OB was 40 +/- 6 mmHg. In all patients (Table 3), severe hypoxia and hypercapnial were observed. TTdi evolution in an OA in 4 patients can be appreciated in Figure 3. It can be concluded that the diaphragmatic strength reserve is reduced in OB so that they are more susceptible to develop diaphragmatic fatigue. A fatigant respiratory pattern was also registered during the OA.

Adult↗