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Biomedical subjects

C Fracchia

Publications and source records attributed to C Fracchia.

At least 37 records · Page 2Linked to original sources
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

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↗
PubMed1993

Effect of pressure and timing of contraction on human rib cage muscle fatigue.

Breathing against inspiratory loads can be accomplished with different degrees of coupling between the diaphragm and the other muscles attached to the rib cage (RCM). Thus, the electromyographic signs of fatigue develop separately in each muscle group. While breathing with diaphragm emphasis, the occurrence of diaphragmatic fatigue was found to be related to the tension-time index TTdi (= Pdi/Pdimax x Ti/Ttot). Above the critical range of 0.15 to 0.18, the endurance of the diaphragm is less than 1 h and it is inversely related to the TTdi value. However, in most loaded breathing conditions, the spontaneous pattern of breathing is characterized by predominant activation of RCM. The tension-time conditions at which fatigue develops during breathing with RCM emphasis are not known. We assessed the critical tension-time value in four normal subjects breathing with RCM emphasis against inspiratory threshold loads. RCM predominance was achieved by developing negative abdominal pressure swings during inspiration, and it was characterized by the tension-time index TTrc (Ppl/Pplmax x Tl/Ttot), where Ppl is pleural pressure developed under this condition. Above a critical TTrc value of 0.30, endurance time was inversely related to TTrc, and it resulted from failure of the RCM rather than of the diaphragm. We conclude that the critical threshold, as assessed by TTrc, is higher for breathing patterns with RCM emphasis than previously described by TTdi for diaphragm emphasis. However, when predominantly recruited, as in breathing patterns commonly adopted in loaded conditions, the RCM fatigue earlier than the diaphragm.

Adult↗
PubMed1993

Effect of nasal pressure support ventilation and external PEEP on diaphragmatic activity in patients with severe stable COPD.

Nasal pressure support ventilation (NPSV) has been shown to be useful in the treatment of acute and chronic pulmonary failure. However, little is known about respiratory muscle activity during NPSV in stable patients with COPD. The aim of this study was to test the effect of two levels (10 and 20 cm H2O) of NPSV on diaphragmatic activity, in a group of seven stable, severe COPD patients (FEV1 20 percent +/- 7 of pred, FEV1/FVC 35 percent) with hypercapnic respiratory insufficiency. Since these patients had an intrinsic PEEP (PEEPi) of 2.6 +/- 1.3 cm H2O, we also investigated the effect of adding 5 cm H2O external PEEP (PEEPe) during NPSV. Blood gases, ventilatory pattern by inductive plethysmography, integrated electromyogram of the diaphragm (Edi), transdiaphragmatic pressure (Pdi), and the diaphragmatic pressure time product (PTPdi) were recorded during randomized 15-min runs of both levels of NPSV with and without the addition of PEEPe. Minute ventilation did not change with the application of NPSV, but a significant decrease in breathing frequency with a parallel increase in tidal volume was observed, so that blood gas determinations improved at the higher levels of support. A marked statistically significant reduction in diaphragmatic activity, as assessed by a decrease in Pdi swings, PTPdi, and Edi, was detected at the levels of 10 and 20 cm H2O; a further significant decrease in these values was observed when PEEPe was added. PEEPi decreased significantly only with the application of PEEPe, resulting in a small increase in end-expiratory lung volume. We conclude that NPSV improves diaphragmatic function in patients with severe stable COPD; this effect may be enhanced by the applications of external PEEP.

Aged↗
PubMed1993

Effect of long-term therapy with oral steroids on respiratory muscle function and ventilatory drive.

It has been shown that chronic oral steroid therapy (ST) does not induce respiratory muscle dysfunction in normal and asthmatic subjects. As corticosteroids are sometimes chronically used in the treatment of the patients with chronic obstructive pulmonary disease (COPD), the aim of our study was to verify whether ST could cause respiratory muscle impairment and, since ST also affects the central nervous system, whether ST could influence the ventilatory pattern. We retrospectively studied 12 COPD patients (group A), on long-term therapy (for at least 4 consecutive months, range 4-18 months) with an oral steroid, deflazacort, 15 mg.d-1. The subjects were strictly matched, with regard to age, sex, height, weight, forced expiratory volume in one second (FEV1), residual volume (RV), arterial oxygen tension (PaCO2), arterial carbon dioxide tension (PaCO2) and pH, with 12 COPD patients (Group B) who had never taken oral steroids. To assess respiratory muscle strength, we measured maximal inspiratory (MIP) and expiratory (MEP) pressures, while mouth occlusion pressure (P0.1) was employed to assess neuromuscular drive; ventilatory pattern and airway impedence were also evaluated. Effectiveness of ST was confirmed by the plasmatic levels of endogenous cortisol. No significant differences were observed between the two groups with regard to MIP (A 72.2 +/- 9.7 vs B: 70 +/- 7.2 cmH2O) and MEP (A 91.6 +/- 10.5 vs B 94.4 +/- 7.6 cmH2O) whilst P0.1 was significantly higher in group A (2.6 +/- 0.3 cmH2O) than in group B (1.8 +/- 0.1 cmH2O). No significant differences were found among all the ventilatory parameters, but the impedence was significantly higher in group A.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1992

Evidence of acute diaphragmatic fatigue in a "natural" condition. The diaphragm during labor.

Acute diaphragmatic fatigue has been experimentally shown to occur in normal healthy subjects and in patients with chronic obstructive pulmonary disease by asking them to modify their pattern of breathing or to breathe against high inspiratory resistances. During the expulsive period of labor women are asked periodically to make strong expulsive efforts and to sustain them isometrically for many seconds; this is likely to produce "natural" diaphragmatic fatigue. To investigate whether this was the case, six women were studied in the delivery room from the moment of the rupture of the amnion until delivery of the infant occurred. The development of diaphragmatic fatigue was assessed both by measuring the static maximal inspiratory pressure (MIP) and by analyzing the electromyographic power spectrum of the diaphragm (H/L ratio). The majority of contractions were concentrated in the expulsive period of labor. MIP, recorded in the supine position, significantly decreased from 103.2 +/- 17.2 cm H2O (at the beginning of the expulsive period) to 73.8 +/- 10.1 cm H2O (after the delivery). The H/L ratio fell progressively during the expulsive period; after the delivery, it was 59.2 +/- 15.7% of the value recorded at the beginning of the expulsive period. This study demonstrates that (1) the diaphragm is active in the expulsive efforts during labor and (2) the tension developed and the time each contraction is maintained may lead to the development of diaphragmatic fatigue. Therefore, we provide evidence of acute diaphragmatic fatigue in a natural condition.

Acute Disease↗
PubMed1992

Effect of a beta 2-agonist (broxaterol) on respiratory muscle strength and endurance in patients with COPD with irreversible airway obstruction.

The effect of broxaterol, a new beta 2-agonist, on respiratory muscle endurance and strength was studied in a double-blind, placebo-controlled, randomized crossover clinical trial in 16 patients with chronic obstructive pulmonary disease (COPD) with irreversible airway obstruction (FEV1 = 57.1 percent of predicted). One patient withdrew from the study because of acute respiratory exacerbation. Inspiratory muscle strength was assessed by maximal inspiratory pressure (MIP) and endurance time was determined as the length of time a subject could breathe against inspiratory resistance (target mouth pressure = 70 percent of MIP, Ti/Ttot = 0.4). Broxaterol (B) or placebo (P) was given orally for seven days at the dose of 0.5 mg three times a day with a washout period of 72 h between study treatments. Measurements were performed before administration of B or P and 2 h (six patients) or 8 h (nine patients) after the end of each treatment. No significant changes in FEV1 or FRC were observed after B or P suggesting that diaphragmatic length was maintained constant with each treatment. The MIP did not significantly change, while endurance time increased after B in the patients tested at 2 h (from 234.8 +/- 48.1 s to 284.0 +/- 48.0 s, p less than 0.05) and at 8 h (from 187.2 +/- 31.1 s to 258.2 +/- 40.4 s, p less than 0.005). No changes were observed after P. Minute ventilation, airway occlusion pressure (P0.1), integrated electromyographic activities of the diaphragm (Edi), and intercostal parasternals (Eic) (normalized to the value obtained during MIP) showed no change during the endurance run with different treatments. We conclude that in a group of COPD patients with irreversible airway obstruction, B significantly improves respiratory muscle endurance, and that this does not arise as a result of an effect on neuromuscular drive or pulmonary mechanics, but may be mediated by peripheral factors.

Adrenergic beta-Agonists↗
PubMed1992

Physiologic evaluation of pressure support ventilation by nasal mask in patients with stable COPD.

We evaluated the physiologic effects of pressure support ventilation by nasal route (NPSV) in eight patients with severe stable COPD and chronic hypercapnia who were randomly submitted to 2-h sessions of NPSV both with a portable ventilator (Respironics BIPAP device) and with a standard ventilator (Bird 6400ST device) at an inspiratory airway pressure of 22 cm H2O. Two sessions with each ventilator were performed using an FIO2 of 0.21 in each patient on two consecutive days. One patient did not tolerate either form of ventilation. Comparison of spontaneous with BIPAP ventilation showed a significant improvement in pH, PaCO2, and PaO2. Ventilatory pattern assessed by a respiratory inductive plethysmograph showed a significant increase in minute ventilation (VE), VT, and Ttot. Integrated surface diaphragmatic EMG activity measured only during BIPAP device ventilation decreased from that measured during spontaneous breathing. Similar changes in blood gases and ventilatory pattern were observed during ventilation by the Bird 6400ST except for VT/Ti ratio, which significantly increased. Comparison of baseline with measurements performed 12 h after the whole cycle of treatment showed a significant increase in pH and VE and a decrease in PaCO2. We conclude that short-term NPSV may be useful in improving respiratory pattern and blood gases in stable COPD patients with chronic hypercapnia.

Humans↗
PubMed1990

Hemodynamic effects of negative-pressure ventilation in patients with COPD.

In order to evaluate the hemodynamic effects of INPV, eight patients with COPD (FEV1/FVC, 54 +/- 6 percent; mean +/- SD), respiratory failure (PaO2, 52 +/- 6 mm Hg; PaCO2, 56 +/- 4 mm Hg), and clinical signs of inspiratory muscle fatigue underwent right cardiac catheterization while performing 20 minutes of INPV by a cuirass ventilator at a pressure (-20 to -40 cm H2O) able to reduce the diaphragmatic electromyographic activity. Patients showed a mild basal pulmonary artery hypertension. During INPV, no changes in the mean values of HR (from 79 +/- 20 to 80 +/- 18 beats per minute), systolic BP (141 +/- 19 to 139 +/- 16 mm Hg), CO (5.2 +/- 0.8 to 5.1 +/- 1.3 L/min), mean PAP (23.8 +/- 3.8 to 23.9 +/- 4.4 mm Hg), RAP (4.3 +/- 2.6 to 5.5 +/- 2.5 mm Hg), PWP (10.3 +/- 4.5 to 9.4 +/- 2.9 mm Hg), TPR (369 +/- 76 to 392 +/- 124 dynes.s.cm-5), and PVR (199 +/- 51 to 233 +/- 94 dynes.s.cm-5) were observed. Direct systemic BP monitoring could be performed in six patients. During INPV, three patients showed "pulsus paradoxus," as assessed by an inspiratory fall in systolic BP of 11, 13, and 20 mm Hg, respectively. We conclude that INPV by cuirass ventilator does not induce adverse hemodynamic effects in patients with COPD who have pulmonary artery hypertension.

Adult↗
PubMed1990

Hypophosphatemia in course of chronic obstructive pulmonary disease. Prevalence, mechanisms, and relationships with skeletal muscle phosphorus content.

Serum phosphorus levels (Ps), dietary intake of phosphorus, and renal phosphate handling indexes were evaluated in 158 patients with chronic obstructive pulmonary disease (COPD) of varying degrees of severity; moreover, skeletal muscle phosphorus content (Pm) was measured in muscle samples obtained by quadriceps femoris needle biopsy in 14 of the same patients. Hypophosphatemia (Ps less than or equal to 2.5 mg/dl) was found in 34 (21.5 percent) of 158 patients without differences between groups of COPD patients presenting increasing severity of respiratory illness. No relationship was found between serum levels and dietary intake of phosphorus; hypophosphatemia was associated with low renal phosphate threshold (TmPO4/GFR) values in 31 (91 percent) of 34 patients. The prevalence of hypophosphatemia was significantly higher among COPD patients taking one or more drugs commonly used in COPD and known as negatively influencing renal phosphate handling: xanthine derivatives, corticosteroids, loop diuretics, and beta 2-adrenergic bronchodilators. Short-term administration of therapeutic doses of these drugs in COPD patients previously not taking any drug reduced TmPO4/GFR values; phosphaturic effect of short-term theophylline administration on renal phosphate handling was additive to that of long-term assumption of the drug. Muscle phosphorus content was both reduced in COPD patients as compared with control subjects and significantly correlated to serum phosphorus levels and to TmPO4/GFR values. The present investigation revealed a high prevalence of hypophosphatemia among COPD patients as well as a defect in renal phosphate reabsorption secondary, at least in part, to pharmacologic therapy. Moreover, it also suggests that in COPD patients muscle phosphorus content is likely to be reduced in presence of hypophosphatemia.

Adult↗
PubMed1990

Simultaneous Doppler and thermodilution assessment of pulmonary artery flow during acute interventions in patients with chronic obstructive pulmonary disease.

Subcostal pulsed wave Doppler echocardiography of the right ventricular outflow tract was used to assess pulmonary arterial flow at basal conditions and during interventions in 20 patients with chronic obstructive pulmonary disease. The changes in the pulmonary flow induced by interventions ranged from -1.5 l/min to +4.18 l/min (73% to 183% of the basal value). When considered alone, heart rate changes induced by the interventions could explain 53% of the changes in pulmonary flow measured with thermodilution. When Doppler-assessed right ventricular stroke volume changes were also considered the coefficient of determination (R) increased to 77% (r = 0.88, p less than 0.001, SEE = 12%). Doppler echocardiography was less precise in predicting absolute basal values of pulmonary artery flow (r = 0.70, p less than 0.001, SEE = 1.00 l/min), probably indicating inaccurate assessment of the diameter of the right ventricular outflow tract.

Administration, Sublingual↗