Biomedical subjects

Isabella Romagnoli

Publications and source records attributed to Isabella Romagnoli.

7 recordsLinked to original sources

PubMed2005

Cortical excitability in obstructive sleep apnea syndrome: transcranial magnetic stimulation study.

STUDY OBJECTIVE: To investigate cortical motor area function in patients with obstructive sleep apnea syndrome (OSAS) during the daytime. DESIGN: The day after a nocturnal polysomnography, transcranial magnetic stimulation (TMS) of the motor cortex was performed recording Motor Evoked Potential from the first dorsal interosseous muscle of the dominant hand. We evaluated: 1) the relaxed motor threshold (RMT), 2) the threshold of the cortical silent period (CSP), 3) the duration of CSP elicited by five stimulus intensities (95%,100%,105%,130%, and 150% of RMT). To estimate the influence of waking on TMS, recordings were performed five times in a day. The Epworth Sleepiness Scale (ESS), and Stanford Sleepiness Scale (SSS) were also measured. SETTING: The study was carried out in the Sleep and Evoked Potentials laboratories of the Don C. Gnocchi Foundation (ONLUS IRCCS) Pozzola tico, (Florence), Italy. PATIENTS: 10 patients with OSAS and 10 healthy volunteers. INTERVENTION: N/A Measurements and Results: In OSAS patients, ESS and SSS were significantly higher than in controls. Patients had a longer duration of CSP at 95%,100% and 105% RMT intensity at almost recording hours; with 130% of RMT stimuli intensity OSAS patients were significantly different at 10AM from controls and with 150% of RMT intensity the difference did not reach significativity. PaCO2 was significantly correlated with CSP duration elicited at 10AM with 95%, 100% and 105% of RMT stimulus intensities. CONCLUSIONS: We found alterations of motor cortical excitability in OSAS patients during the daytime. We believe that PaCO2 levels, acting probably on various ion channels or metabolic pathways, may change the excitability of motor cortex modifying excitatory and inhibitory cortical circuits.

Adult↗

PubMed2004

Walking modality affects respiratory muscle action and contribution to respiratory effort.

We hypothesized that walking at increased speed or increasing gradient might have different effects on chest wall kinematics and respiratory muscle power components, and contribute differently to respiratory effort sensation. We measured the volumes of chest wall compartments by optoelectronic plethysmography, esophageal, gastric and transdiaphragmatic ( P(di)) pressures, and the sensation of the respiratory effort by a Borg scale in five normal subjects walking both at ascending gradient with constant speed (AG) and at ascending speed with constant gradient (AS). Chest wall kinematics, evaluated by displacement of chest wall compartments, did not show any significant difference between AS and AG. Muscle power, calculated as the product of mean flow and mean pressure, increased similarly, but its partitioning into pressure and velocity of shortening differed in the two modes. A greater increase in the pressure developed by the abdominal muscles ( P(abm)) (4.06-fold), and in the velocity of shortening of both rib cage inspiratory muscles ( v(rcm,i)) (2.01-fold) and the diaphragm ( v(di)) (1.90-fold) was associated with a lower increase in the pressure developed by the rib cage inspiratory muscles ( P(rcm,i)) (1.24-fold) and P(di) (0.99-fold) with AG. Instead, with AS, a lower increase in P(abm) (2.12-fold), v(rcm,i) (1.66-fold) and v(di) (1.54-fold) was associated with a greater increase in P(rcm,i) (1.56-fold) and P(di) (1.97-fold). A combination of P(abm) and v(di) during AG (Wald chi(2)=23.19, P<0.0000), with the addition of P(rcm,i) during AS (Wald chi(2)=29.46, P<0.0000), was the best predictor of Borg score. In conclusion, the general strategy adopted by respiratory centers during different walking modes does not differ in terms of ventilation, chest wall kinematics, and respiratory muscle power production, whereas it does in terms of partitioning of power into pressure and velocity of shortening, and respiratory muscle contribution to respiratory effort sensation. Combinations of different patterns of flow and pressure generation made the respiratory effort sensation similar during AS and AG modes.

Adult↗

PubMed2004

Chest wall kinematics and breathlessness during pursed-lip breathing in patients with COPD.

BACKGROUND: Pursed-lip breathing (PLB) is a strategy often spontaneously employed by patients with COPD during distress situations. Whether and to what extent PLB affects operational lung volume is not known. Also, conflicting reports deal with PLB capability of decreasing breathlessness. PARTICIPANTS AND MEASUREMENTS: Twenty-two patients with mild-to-severe COPD were studied. Volumes of chest wall (CW) compartments (rib cage [RC] and abdomen) were assessed using an optoelectronic plethysmograph. Dyspnea was assessed by a modified Borg scale. RESULTS: Compared to spontaneous breathing, patients with PLB exhibited a significant reduction (mean +/- SD) in end-expiratory volume of the CW (VCW) [VCWee; - 0.33 +/- 0.24 L, p < 0.000004], and a significant increase in end-inspiratory VCW (VCWei; + 0.32 +/- 0.43 L, p < 0.003). The decrease in VCWee, mostly due to the decrease in end-expiratory volume of the abdomen (VAbee) [- 0.25 +/- 0.21 L, p < 0.00002], related to baseline FEV(1) (p < 0.02) and to the increase in expiratory time (TE) [r(2) = 0.49, p < 0.0003] and total time of the respiratory cycle (TTOT) [r(2) = 0.35, p < 0.004], but not to baseline functional residual capacity (FRC). Increase in tidal volume (VT) of the chest wall (+ 0.65 +/- 0.48 L, p < 0.000004) was shared between VT of the abdomen (0.31 +/- 0.23 L, p < 0.000004) and VT of the rib cage (+ 0.33 +/- 0.29 L, p < 0.00003). Borg score decreased with PLB (p < 0.04). In a stepwise multiple regression analysis, decrease in VCWee accounted for 27% of the variability in Borg score at 99% confidence level (p < 0.008). CONCLUSIONS: Changes in VCWee related to baseline airway obstruction but not to hyperinflation (FRC). By lengthening of TE and TTOT, PLB decreases VCWee and reduces breathlessness.

Aged↗

PubMed2003

Chest wall kinematics in patients with hemiplegia.

Owing to difficulties in measuring ventilation symmetry, good evidence of different right/left respiratory movements has not yet been provided. We investigated VT differences between paretic and healthy sides during quiet breathing, voluntary hyperventilation, and hypercapnic stimulation in patients with hemiparesis. We studied eight patients with hemiparesis and nine normal sex- and age-matched subjects. Right- and left-sided VT was reconstructed using optoelectronic plethysmography. In control subjects, no asymmetry was found in the study conditions. VTs of paretic and healthy sides were similar during quiet breathing, but paretic VT was lower during voluntary hyperventilation in six patients and higher during hypercapnic stimulation in eight patients (p = 0.02). The ventilatory response to hypercapnic stimulation was higher on the paretic than on the healthy side (p = 0.012). In conclusion, hemiparetic stroke produces asymmetric ventilation with an increase in carbon dioxide sensitivity and a decrease in voluntary ventilation on the paretic side.

Adult↗

PubMed2003

Exercise training improves exertional dyspnea in patients with COPD: evidence of the role of mechanical factors.

BACKGROUND: To our knowledge, no data have been reported on the effects of exercise training (EXT) on central respiratory motor output or neuromuscular coupling (NMC) of the ventilatory pump, and their potential association with exertional dyspnea. Accurate assessment of these important clinical outcomes is integral to effective management of breathlessness of patients with COPD. MATERIAL AND METHODS: Twenty consecutive patients with stable moderate-to-severe COPD were tested at 6-week intervals at baseline, after a nonintervention control period (pre-EXT), and after EXT. Patients entered an outpatient pulmonary rehabilitation program involving regular exercise on a bicycle. Incremental symptom-limited exercise testing (1-min increments of 10 W) was performed on an electronically braked cycle ergometer. Oxygen uptake (O(2)), carbon dioxide output (CO(2)), minute ventilation (E), time, and volume components of the respiratory cycle and, in six patients, esophageal pressure swings (Pessw), both as actual values and as percentage of maximal (most negative in sign) esophageal pressure during sniff maneuver (Pessn), were measured continuously over the runs. Exertional dyspnea and leg effort were evaluated by administering a Borg scale. RESULTS: Measurements at baseline and pre-EXT were similar. Significant increase in exercise capacity was found in response to EXT: (1) peak work rate (WR), O(2), CO(2), E, tidal volume (VT), and heart rate increased, while peak exertional dyspnea and leg effort did not significantly change; (2) exertional dyspnea/O(2) and exertional dyspnea/CO(2) decreased while E/O(2) and E/CO(2) remained unchanged. The slope of both exertional dyspnea and leg effort relative to E fell significantly after EXT; (3) at standardized WR, E, and CO(2), exertional dyspnea and leg effort decreased while inspiratory capacity (IC) increased. Decrease in E was accomplished primarily by decrease in respiratory rate (RR) and increase in both inspiratory time (TI) and expiratory time; VT slightly increased, while inspiratory drive (VT/TI) and duty cycle (TI/total time of the respiratory cycle) remained unchanged. The decrease in Pessw and the increase in VT were associated with lower exertional dyspnea after EXT; (4) at standardized E, VT, RR, and IC, Pessw and Pessw(%Pessn)/VT remained unchanged while exertional dyspnea and leg effort decreased with EXT. CONCLUSION: In conclusion, increases in NMC, aerobic capacity, and tolerance to dyspnogenic stimuli and possibly breathing retraining are likely to contribute to the relief of both exertional dyspnea and leg effort after EXT.

Carbon Dioxide↗

PubMed2002

Dissociation between respiratory effort and dyspnoea in a subset of patients with stroke.

Dyspnoea is not a prominent complaint of resting patients with recent hemispheric stroke (RHS). We hypothesized that, in patients with RHS presenting abnormalities in respiratory mechanics, increased respiratory motor output could translate into an increased perception of dyspnoea. We studied eight wheelchair-bound patients with RHS (mean age 62.4 years), previously evaluated by computerized tomography scanning, and a control group of normal subjects, matched for age and sex. We assessed routine spirometry, inspiratory and expiratory muscle pressures, breathing pattern and dyspnoea using a modified Borg scale. In six patients, we also measured oesophageal pressure during the maximal sniff manoeuvre and tidal inspiratory swing, and mechanical characteristics of the lung in terms of dynamic elastance during both quiet breathing and a hypercapnic/hyperoxic rebreathing test. During room air breathing, ventilation and tidal volume were similar in patients and controls, while tidal inspiratory swings of oesophageal pressure, an index of inspiratory motor output, were greater in patients ( P =0.005). Patients also exhibited a greater dynamic elastance ( P =0.013). During rebreathing, dynamic elastance remained higher ( P =0.01) and a greater than normal inspiratory motor output was found ( P =0.03). Responses of ventilation and tidal volume to carbon dioxide tension were normal, and in all patients but one a lower Borg score for the unit change in carbon dioxide tension and ventilation was found. In conclusion, a higher than normal inspiratory motor output was unexpectedly associated with a blunted perception of dyspnoea in this subset of RHS patients. This is likely to be due to the modulation of the integration process of respiratory sensation.

Adult↗

PubMed2002

Inspiratory capacity and decrease in lung hyperinflation with albuterol in COPD.

STUDY OBJECTIVES: Inspiratory capacity (IC) has been proposed as a simple method to assess acute changes in functional residual capacity (FRC) with bronchodilation, assuming that total lung capacity (TLC) is unchanged. This assumption is based on studies using body plethysmography, which may not accurately measure TLC in severely obstructed subjects. The aim of this study is to validate the use of IC measured by optoelectronic plethysmography (OEP) [ICOEP], a noninvasive technique capable of computing changes in absolute lung volumes with great accuracy. MEWTHODS AND MEASUREMENTS: We studied 13 subjects with COPD in clinically stable condition at baseline and after 200 microg of inhaled albuterol. Changes in lung volumes were obtained from changes in chest wall volume (Vcw) measured by OEP and were compared with those measured by standard techniques. RESULTS: Albuterol treatment caused a small but significant increase in FEV(1) and FVC, a significant decrease of Vcw at FRC (VcwFRC), but no changes of Vcw at TLC (VcwTLC) and breathing pattern variables. The reduction of VcwFRC was not correlated with either spirometric or breathing-pattern variables. IC measured with a pneumotachograph was highly correlated with and not significantly different from ICOEP (p < 0.001). CONCLUSIONS: A single dose of inhaled albuterol does not significantly modify VcwTLC in subjects with COPD, thus validating the use of IC to measure changes of FRC in the assessment of reversibility of airway obstruction.

Administration, Inhalation↗