Work of breathing and lung volume during forward leaning supported by the upper limbs.

This study compared work of breathing (WOB) and the pressure time product (PTP) to verify whether WOB and PTP decrease in the forward-leaning posture compared with erect sitting. Seven healthy adults (two females and five males) adopted three sitting postures: upright, and two forward-leaning postures of 15° and 30°. The WOB was obtained using the modified Campbell diagram, and PTP was calculated as the time integral of the area between esophageal and chest wall pressure. End-expiratory lung volume and transpulmonary pressure were significantly increased in the 15° and 30° forward-leaning postures compared with erect sitting (p â‰¦ 0.05). End-inspiratory lung volume was significantly increased in the 30° forward-leaning posture compared to erect sitting (p â‰¦ 0.05). PTP and inspiratory resistive WOB were significantly lower in the 15° and 30° forward-leaning postures compared to erect sitting (p â‰¦ 0.05). Forward leaning increases lung volume, which may dilate the airways, decrease resistant WOB, and reduce respiratory muscle activity.

Changes in ventilation mechanics during expiratory rib cage compression in healthy males.

[Purpose] The purpose of this study was to clarify the differences in ventilation mechanics between quiet breathing and expiratory rib cage compression, and between expiratory rib cage compression on the upper rib cage and on the lower rib cage. [Subjects and Methods] Subjects comprised 6 healthy males. Expiratory rib cage compression was performed manually by compressing the upper and lower rib cages. Changes in the lung volume, flow rate, and esophageal and gastric pressure were examined. [Results] The end expiratory lung volume was significantly lower during expiratory rib cage compression than at rest, but the end inspiratory lung volume was not significantly different. When compared with the esophageal and gastric pressures on the upper and lower rib cages at rest, the gastric pressures were significantly higher at end expiration. Lung resistance was significantly higher during expiratory rib cage compression than at rest. [Conclusion] Although expiratory rib cage compression promoted expiration and increased tidal volume, the lung volume did not increase beyond end inspiratory levels at rest. Lung resistance may increase during expiratory rib cage compression due to a decrease in lung volume. The mechanism by which expiration is promoted differed between the upper and lower rib cages.

Effects of posture on chest-wall configuration and motion during tidal breathing in normal men.

[Purpose] The purpose of this study was to clarify the impact of postural changes during tidal breathing on the configuration and motion of chest-wall in order to further breathing motion evaluation. [Subjects and Methods] Chest-wall configuration and motion in the supine, right lateral, and sitting positions were measured using optoelectronic plethysmography in 15 healthy adult men. [Results] The anteroposterior diameters of the chest wall were significantly lower in the supine position for the pulmonary and abdominal rib cages, whereas the mediolateral diameters in the lateral position were lowest for the abdominal rib cage. Regarding chest-wall motion, both craniocaudal and anteroposterior motions of the anterior surface of the pulmonary and abdominal rib cages were significantly greater in the sitting position. Regarding motion of the left lateral abdominal rib cage, lateral motion was greatest in the lateral position. [Conclusion] Chest-wall configuration and motion changed according to posture in healthy men, particularly in the pulmonary and abdominal rib cages.

Validity of Quadriceps Muscle Thickness Measurement in Patients with Subacute Stroke during Hospitalization for Assessment of Muscle Wasting and Physical Function.

BACKGROUND: Many patients with stroke have difficulty performing voluntary muscle contraction; thus, measurement of patients' muscle power or leg strength is challenging. We investigated the validity of quadriceps muscle thickness (QMT) measurement using ultrasonography (US) for the assessment of muscle wasting and physical function in patients with subacute stroke during hospitalization for convalescent rehabilitation. METHODS: Participants included 52 men with ischemic or hemorrhagic stroke (mean age, 69 ± 11 years) who were hospitalized for inpatient convalescent rehabilitation. The QMT of both legs was measured using US, and functional outcome was assessed according to the modified Rankin Scale (mRS) score and the leg motor selectivity score (6 motor stages defined by Brunnstrom). RESULTS: There was a significant correlation between QMT and leg motor selectivity score (paretic limb: r = .60, P < .001; nonparetic limb: r = .54, P < .001). Additionally, there were significant interaction effects between the QMT of the paretic limb (mRS scores = 1 or 2, 3, 4, and 5 = 3.52 ± .84 cm, 3.19 ± .52 cm, 2.50 ± .46 cm, and 2.20 ± .71 cm, respectively; F = 11.2; P < .0001), the QMT of the nonparetic limb (mRS scores = 1 or 2, 3, 4, and 5 = 3.72 ± .82 cm, 3.16 ± .49 cm, 2.91 ± .54 cm, and 2.42 ± .82 cm, respectively; F = 8.3; P < .001), and functional outcome. CONCLUSION: QMT measurement is a valid method to assess muscle wasting and physical function in patients with subacute stroke during hospitalization for convalescent rehabilitation.

Compression of the lungs by the heart in supine, side-lying, semi-prone positions.

[Purpose] Clarification of the differences in the compression volume of the lungs by the heart (CVLH) between postures may facilitate the selection of optimal postures in respiratory care. Determining CVLH in the supine, semi-prone (Sim's position), and side-lying positions was the aim of this study. [Subjects and Methods] Eight healthy volunteers (six males, two females; mean age, 29.0 ± 9.2 years) were enrolled in the study. Measurements were performed in the supine, right and left semi-prone, and right and left side-lying positions. semi-prone position was inclined 45° ventrally from the side-lying position. A 1.5-T system with a fast advanced spin-echo sequence in the coronal plane was used for magnetic resonance imaging. [Results] CVLH and heart compression ratio were significantly lower in the semi-prone position on both sides than the other positions. The heart was displaced ventrally when semi-prone and a larger area of the heart leaned on the ventral chest wall, localizing compression to part of the ventral region of the dependent lung. [Conclusion] The region of lungs compressed by the heart is reduced in the semi-prone position due to ventral displacement of the heart. These results suggest that maintaining expansion of the dependent lung is easier in the semi-prone position.

Changes in Quadriceps Muscle Thickness, Disease Severity, Nutritional Status, and C-Reactive Protein after Acute Stroke.

BACKGROUND: Lower leg muscle wasting is common in stroke patients; however, patient characteristics in the acute phase are rarely studied. This study aimed to examine the relationship between changes in quadriceps muscle thickness and disease severity, nutritional status, and C-reactive protein (CRP) levels after acute stroke. METHODS: Thirty-one consecutive patients with acute intracerebral hemorrhage or ischemic stroke had quadriceps muscle thickness measured in the paretic and nonparetic limbs within 1 week after admission (first week) and 2 weeks after the first examination (last week) using ultrasonography. We also determined the relationship between the percentage change in muscle thickness and disease severity, nutritional status, and CRP levels on admission. RESULTS: There was a significant correlation between changes in muscle thickness for both paretic and nonparetic sides and National Institutes of Health Stroke Scale (NIHSS) scores (paretic limb: r = -.46, P = .01; nonparetic limb: r = -.54, P = .002, respectively); however, there was no significant correlation with nutritional status on admission. Quadriceps muscle thickness was reduced more in the CRP-positive (≥.3 mg/dL) patients than in the CRP-negative (<.3 mg/dL) patients in the nonparetic limb (positive: -21.4 ± 12.1, negative: -11.4 ± 16.4%; P = .039), but not in the paretic limb (positive: -23.4 ± 9.0, negative: -19.1 ± 15.7; P = .27). CONCLUSIONS: A high NIHSS score and a positive CRP on admission were both significantly correlated with decreased quadriceps muscle thickness after acute stroke. Nutritional status on admission was not correlated with changes in quadriceps muscle thickness for these patients.

Effects of chest wall compression on expiratory flow rates in patients with chronic obstructive pulmonary disease

Background: Manual chest wall compression (CWC) during expiration is a technique for removing airway secretions in patients with respiratory disorders. However, there have been no reports about the physiological effects of CWC in patients with chronic obstructive pulmonary disease (COPD). Objective: To compare the effects of CWC on expiratory flow rates in patients with COPD and asymptomatic controls. Method: Fourteen subjects were recruited from among patients with COPD who were receiving pulmonary rehabilitation at the University Hospital (COPD group). Fourteen age-matched healthy subjects were also consecutively recruited from the local community (Healthy control group). Airflow and lung volume changes were measured continuously with the subjects lying in supine position during 1 minute of quiet breathing (QB) and during 1 minute of CWC by a physical therapist. Results: During CWC, both the COPD group and the healthy control group showed significantly higher peak expiratory flow rates (PEFRs) than during QB (mean difference for COPD group 0.14 L/sec, 95% confidence interval (CI) 0.04 to 0.24, p<0.01, mean difference for healthy control group 0.39 L/sec, 95% CI 0.25 to 0.57, p<0.01). In the between-group comparisons, PEFR was significantly higher in the healthy control group than in the COPD group (-0.25 L/sec, 95% CI -0.43 to -0.07, p<0.01). However, the expiratory flow rates at the lung volume at the PEFR during QB and at 50% and 25% of tidal volume during QB increased in the healthy control group (mean difference for healthy control group 0.31 L/sec, 95% CI 0.15 to 0.47, p<0.01: 0.31 L/sec, 95% CI 0.15 to 0.47, p<0.01: 0.27 L/sec, 95% CI 0.13 to 0.41, p<0.01, respectively) but not in the COPD group (0.05 L/sec, 95% CI -0.01 to 0.12: -0.01 L/sec, 95% CI -0.11 to 0.08: 0.02 L/sec, 95% CI -0.05 to 0.90) with the application of CWC. Conclusion: The effects of chest wall compression on expiratory flow rates was different between COPD patients and asymptomatic controls.

Effects of chest wall compression on expiratory flow rates in patients with chronic obstructive pulmonary disease.

BACKGROUND: Manual chest wall compression (CWC) during expiration is a technique for removing airway secretions in patients with respiratory disorders. However, there have been no reports about the physiological effects of CWC in patients with chronic obstructive pulmonary disease (COPD). OBJECTIVE: To compare the effects of CWC on expiratory flow rates in patients with COPD and asymptomatic controls. METHOD: Fourteen subjects were recruited from among patients with COPD who were receiving pulmonary rehabilitation at the University Hospital (COPD group). Fourteen age-matched healthy subjects were also consecutively recruited from the local community (Healthy control group). Airflow and lung volume changes were measured continuously with the subjects lying in supine position during 1 minute of quiet breathing (QB) and during 1 minute of CWC by a physical therapist. RESULTS: During CWC, both the COPD group and the healthy control group showed significantly higher peak expiratory flow rates (PEFRs) than during QB (mean difference for COPD group 0.14 L/sec, 95% confidence interval (CI) 0.04 to 0.24, p<0.01, mean difference for healthy control group 0.39 L/sec, 95% CI 0.25 to 0.57, p<0.01). In the between-group comparisons, PEFR was significantly higher in the healthy control group than in the COPD group (-0.25 L/sec, 95% CI -0.43 to -0.07, p<0.01). However, the expiratory flow rates at the lung volume at the PEFR during QB and at 50% and 25% of tidal volume during QB increased in the healthy control group (mean difference for healthy control group 0.31 L/sec, 95% CI 0.15 to 0.47, p<0.01: 0.31 L/sec, 95% CI 0.15 to 0.47, p<0.01: 0.27 L/sec, 95% CI 0.13 to 0.41, p<0.01, respectively) but not in the COPD group (0.05 L/sec, 95% CI -0.01 to 0.12: -0.01 L/sec, 95% CI -0.11 to 0.08: 0.02 L/sec, 95% CI -0.05 to 0.90) with the application of CWC. CONCLUSION: The effects of chest wall compression on expiratory flow rates was different between COPD patients and asymptomatic controls.

Measurements of chest wall volume variation during tidal breathing in the supine and lateral positions in healthy subjects.

PURPOSE: To study the feasibility and the laterality of measurements of chest wall volume variation during tidal breathing in the lateral position in healthy subjects. METHODS: Eighteen normal subjects were studied. Chest wall volume changes were measured by optoelectronic plethysmography in the supine and right and left lateral positions during quiet breathing. The accuracy of measuring lung volume was also examined using hot wire spirometry in 10 of the subjects. RESULTS: The measurement errors between lung volume changes and chest wall volume changes were not significantly different in all positions. There was no significant difference between right and left compartmental volume changes in the supine position. However, chest wall volume changes were lower on the dependent side in the lateral position than on the non-dependent side because of the decrease in abdominal rib cage and abdomen volume changes. CONCLUSION: Chest wall volume measurements during quiet breathing in the lateral position have high measuring accuracy and show laterality.

Use of glucose solution for the alleviation of gemcitabine-induced vascular pain: a double-blind randomized crossover study.

PURPOSE: Gemcitabine is widely used for chemotherapy in many types of cancers. However, vascular pain frequently occurs during its infusion, which can be serious enough to cause treatment discontinuation. This study was conducted to determine whether dissolution with 5 % glucose solution would relieve vascular pain compared with the approved use of saline as the diluent. METHODS: Patients with cancer who were treated with weekly gemcitabine were eligible. Vascular pain was assessed during two consecutive administrations in a double-blind, randomized crossover study. One group was scheduled to receive gemcitabine dissolved in saline followed by gemcitabine in 5 % glucose solution. In the other group, 5 % glucose solution was followed by saline. The primary endpoint was frequency of vascular pain for the total infusions of each solvent and the secondary endpoints were intensity, as assessed on a visual analogue scale and duration of vascular pain. RESULTS: Eighty-seven patients were randomly assigned to each treatment schedule. Frequency of vascular pain was significantly lower with 5 % glucose solution compared with saline (40 versus 63 %; p < 0.001). The intensity of vascular pain was also reduced with 5 % glucose solution compared with saline (mean, 1.3 versus 2.7 points; p < 0.001). There was no significant statistical difference in duration of vascular pain between the 5 % glucose solution and saline solution groups (mean, 21 versus 18 min; p = 0.420). CONCLUSIONS: The use of 5 % glucose solution to dissolve gemcitabine significantly reduced the frequency and the intensity of vascular pain compared with the use of saline.

Relationship between spontaneous expiratory flow-volume curve pattern and air-flow obstruction in elderly COPD patients.

BACKGROUND: Assessment of the degree of air-flow obstruction is important for determining the treatment strategy in COPD patients. However, in some elderly COPD patients, measuring FVC is impossible because of cognitive dysfunction or severe dyspnea. In such patients a simple test of airways obstruction requiring only a short run of tidal breathing would be useful. We studied whether the spontaneous expiratory flow-volume (SEFV) curve pattern reflects the degree of air-flow obstruction in elderly COPD patients. METHODS: In 34 elderly subjects (mean ± SD age 80 ± 7 y) with stable COPD (percent-of-predicted FEV(1) 39.0 ± 18.5%), and 12 age-matched healthy subjects, we measured FVC and recorded flow-volume curves during quiet breathing. We studied the SEFV curve patterns (concavity/convexity), spirometry results, breathing patterns, and demographics. The SEFV curve concavity/convexity prediction accuracy was examined by calculating the receiver operating characteristic curves, cutoff values, area under the curve, sensitivity, and specificity. RESULTS: Fourteen subjects with COPD had a concave SEFV curve. All the healthy subjects had convex SEFV curves. The COPD subjects who had concave SEFV curves often had very severe airway obstruction. The percent-of-predicted FEV(1)% (32.4%) was the most powerful SEFV curve concavity predictor (area under the curve 0.92, 95% CI 0.83-1.00), and had the highest sensitivity (0.93) and specificity (0.88). CONCLUSIONS: Concavity of the SEFV curve obtained during tidal breathing may be a useful test for determining the presence of very severe obstruction in elderly patients unable to perform a satisfactory FVC maneuver.