Comparison of circadian variations using FEV1 and peak expiratory flow rates among normal and asthmatic subjects.

BACKGROUND--Most studies that describe circadian variations in asthma have used maximum rate of peak expiratory flow (PEF) rather than forced expiratory volume in one second (FEV1) to assess airway calibre. This study was designed to assess circadian variations in PEF and FEV1 measured simultaneously and to compare variations in these measurements in normal and asthmatic subjects in a stable clinical state. METHODS--Twenty nine subjects (nine asthmatic subjects on bronchodilators, 10 on inhaled steroids, and 10 normal controls) were asked to record their PEF and FEV1 with a new portable instrument every two hours during the day and once on waking at night for two weeks. Circadian variations were examined in different ways using arithmetical indices and cosinor analysis. RESULTS--78% of PEF values and 75% of FEV1 values were considered to be reproducible and were included in the analysis. Variations obtained using PEF did not differ from those obtained using FEV1. Significant cosinor variations were found in at least 50% of recording days for most of the subjects and showed the same features as for arithmetical indices. Daily variations in PEF and FEV1 were significantly correlated with airway calibre and PC20 methacholine (r approximately 0.5 to approximately 0.6). CONCLUSIONS--PEF is as satisfactory as FEV1 for describing circadian variations among normal subjects and stable asthmatic subjects.     

Changes in specific airways conductance and forced expiratory volume in one second after a bronchodilator in normal subjects and patients with airways obstruction

Skinner, C. and Palmer, K.N.V. (1974).Thorax, 29, 574-577. Changes in specific airways conductance and forced expiratory volume in one second after a bronchodilator in normal subjects and patients with airways obstruction. Specific conductance (SGaw) and the forced expiratory volume in one second (FEV₁) were measured in 10 normal, 10 asthmatic, and 10 obstructive bronchitic subjects before and after aerosol salbutamol. Mean SGaw increased by 37% in normals, by 109% in asthmatics, and by 38% in obstructive bronchitics. Mean FEV₁ increased by 2% in normals, by 32% in asthmatics, and by 12% in obstructive bronchitics. SGaw appears to be a more sensitive indicator than FEV₁ of changes in airways calibre following a bronchodilator drug in normal subjects, but FEV₁ is as good an indicator of these changes as SGaw in patients with airways obstruction.     

Discordance between predicted postoperative forced expiratory volumes in one second (ppoFEV1) calculated before and after resection of bronchogenic carcinoma

The aim of this study is to evaluate the concordance between predicted postoperative forced expiratory volumes in 1s (ppoFEV1) calculated on the basis of data known before surgery with ppoFEV1 calculated after completing surgical procedure. We have prospectively studied 66 consecutive patients (55 cases scheduled for lobectomy and 11 for pneumonectomy) operated on for bronchial carcinoma. According to location, 33 tumours were classified as central and 33 as peripheral. In all cases, ppoFEV1 was calculated twice: first (ppoFEV1-A) according to the scheduled surgical procedure; second (ppoFEV1-B) according to the procedure eventually performed. At operation, 43 lobectomies (65.2%) and 23 pneumonectomies (34.8%) were performed. Differences between ppoFEV1 A and B were found in 18 cases (12 central tumours). In three of them (4.5% of 66 cases), ppoFEV1-B was under 40%. Pearson coefficient was 0.85 (P<0.001) for the whole series of cases; 0.83 (P<0.001) for central and 0.87 (P<0.001) for peripheral tumours. On multiple regression analysis, R2 was 0.76 and ppoFEV1-A had the highest influence on the dependent variable. We have found that: (1) there is no perfect correlation between ppoFEV1 calculated with data known before and after surgery; (2) discrepancies are most important in centrally located tumours and (3) in 4.5% of cases, discrepancies could have influenced the preoperative risk estimation.     

Sonographic evaluation of the shoulder in asymptomatic elderly subjects with diabetes

Background  

The prevalence of rotator cuff tears increases with age and several studies have shown that diabetes is associated with symptomatic shoulder pathologies. Aim of our research was to evaluate the prevalence of shoulder lesions in a population of asymptomatic elderly subjects, normal and with non insulin - dependent diabetes mellitus.     

Effects of propranolol inhalation on the diurnal increase in FEV1 and on propranolol airways responsiveness in atopic subjects with asthma.

BACKGROUND--Propranolol inhalation provocation tests are used to measure indirect airways responsiveness in the investigation of asthma. In this study the effects of repeated propranolol inhalation provocation tests within the same day on normal diurnal variation in the forced expiratory volume in one second (FEV1) and subsequent propranolol airways responsiveness were investigated. METHODS--Fifteen atopic asthmatic subjects were challenged with doubling concentrations of propranolol at 08.00 and 16.00 hours on the same study day and at 16.00 hours on a control day to exclude changes related to normal diurnal variation. RESULTS--Mean (SD) baseline FEV1 at 16.00 hours on the study day was 3.38 (0.23) 1, significantly lower than the value at 16.00 hours on the control day of 3.70 (0.24) 1 (p = 0.001). No differences were found between the geometric mean provocative concentration of propranolol causing a 20% fall in FEV1 (PC20) measured on the study day (08.00 hours, 9.3 mg/ml; 16.00 hours, 11.3 mg/ml) and on the control day (16.00 hours 9.3 mg/ml). CONCLUSIONS--The results suggest that propranolol provocation at 08.00 hours has a long lasting effect on FEV1, thereby counteracting the normal diurnal increase in diameter of the airways. This makes propranolol challenge tests less suitable for studying indirect airways responsiveness in the course of one day. Because the FEV1 does not return to control values, it is not possible to determine whether tachyphylaxis to repeated propranolol challenge with a time interval of up to eight hours occurs.     

Risk factors for rate of decline in FEV(1) in adults with cystic fibrosis

BackgroundPreviously we assessed risk factors for FEV₁ decline in children and adolescents using the Epidemiologic Study of Cystic Fibrosis (J Pediatr 2007;151:134–139); the current study assessed risk factors in adults.MethodsRisk factors for FEV₁ decline over 3–5.5 years for ages 18–24 and ≥ 25 years were assessed using mixed-model regression.ResultsMean rates of FEV₁ decline (% predicted/year) were − 1.92 for ages 18-24y (n = 2793) and − 1.45 for ages ≥ 25y (n = 1368). For the 18-24y group, B. cepacia, pancreatic enzyme use, multidrug-resistant P. aeruginosa, cough, mucoid P. aeruginosa, and female sex predicted greater decline; low baseline FEV₁ and sinusitis predicted less decline. For the ≥ 25y group, only pancreatic enzyme use predicted greater decline; low baseline FEV₁ and sinusitis predicted less decline.ConclusionsRisk factors for FEV₁ decline in adults < 25 years are similar to those previously identified in children and adolescents; older adults had few statistically significant risk factors.     

Evaluation of two techniques for measurement of respiratory resistance by forced oscillation: A study in young subjects with obstructive lung disease

The measurement of respiratory resistance by forced oscillation requires minimal patient co-operation and should be a useful test in children. Sixty-eight children and adolescents with obstructive lung disease were studied using two different techniques. In patients with severe obstructive lung disease, unexpectedly low values for respiratory resistance were found when the measurement was made at points of peak flow (write-out method). Measurements made at simulated resonant frequency (subtraction method) in these patients were more in keeping with other tests of respiratory function; however, they probably did not reflect true respiratory resistance. The subtraction method of measuring respiratory resistance would seem to be of value in separating the normal from the abnormal, but the absolute values in obstructed subjects are difficult to interpret.     

Isokinetic assessment of spasticity in subjects with traumatic spinal cord injury (ASIA A).

OBJECTIVE: To assess resistance to passive isokinetic movements at specified speeds and range of motion, as a measure of muscular tonus. METHODS: A group of 12 subjects with complete traumatic spinal cord injury and a group of 12 able-bodied subjects were analysed, distinguishing the level of spasticity in the SCI group. Maximum eccentric peak torque was observed in passive isokinetic flexion (F) and extension (E) knee movement in displacements of 30, 60 and 120 per second. RESULTS: The Student t-test showed that the average torque in the injured group was significantly higher than in the control group (F= 120 degrees per second, P<0.001). Variance analysis showed that the lower level presented lower torque levels (E=60 and 120 degrees per second, P<0.032), while those in the higher level presented higher torque levels (F and E=60 and 120 per second, P<0.032) when compared to the control group. In the control group the Student t-test (P<0.0006) showed a significantly different muscle behavior (Flexion>Extension Torque). CONCLUSION: By using isokinetic assessment it was possible to quantify hypertonic spasticity in a group of subjects with spinal cord injury, distinguishing groups with higher and lower levels of spasticity as compared to a control group.     

Improving rate of decline of FEV1 in young adults with cystic fibrosis

BACKGROUND: CF is characterised by a progressive decline in lung function; reductions in this decline are often used as a measure of success in clinical trials. With improvements in treatment it may be that there has been a temporal shift in the pattern of the disease. METHODS: 318 patients born in five successive cohorts and attending a specialist clinic with at least two routine measurements of lung function made between the ages of 18 and 22 were included. The declines in their lung function were estimated and compared. RESULTS: The mean (SE) slopes for percentage predicted forced expiratory volume in 1 second (FEV(1)) and forced vital capacity (FVC) were -1.53 (0.36)% and -1.27 (0.34)%, respectively (NS). The annual deterioration in FEV(1) was -2.49%, -1.99% -2.20%, -1.65%, and -0.65% from the earliest to the most recent birth cohort; a similar pattern was observed for changes in FVC. There were no differences between male and female patients. Patients infected with Pseudomonas had a greater average decline in FEV(1) (-1.6% v -1.1%). CONCLUSIONS: The rates of decline in lung function in young adults with CF have diminished with successive birth cohorts. This has important implications for the design of clinical studies in this disease.     

Influence of age and predicted forced expiratory volume in 1 s on prognosis following complete resection for non-small cell lung carcinoma.

OBJECTIVE: To evaluate age of the patient at the time of surgery and estimated postoperative forced expiratory volume in 1 s (FEV1%) as predictors of long-term survival following complete resection of non-small cell lung carcinoma (NSCLC). METHODS: Retrospective, observational study. Records of patients operated on for NSCLC between January 1994 and December 1997 were reviewed. One hundred and ninety three patients who underwent complete pathological resection and survived surgery were included for study. Patients were divided in groups depending on age at the time of surgery and predicted postoperative FEV1% calculated according to the number of resected segments. Values of the 75th percentile of age (70.29 years) and 50th percentile of predicted FEV1% (52.9) were the cut-points selected for group division. To increase the power of the analysis pathological staging was also converted in a binary variable and resumed to localized (stage I) or extended (stage II-IIIB). Univariate analysis of the effect of each variable on survival was assessed by Kaplan-Meier method and log-rank test. Relationship between variables was investigated using 2x2 tables and Fisher's exact test. Unrelated variables (extension, age and low estimated postoperative FEV1%) entered in a Cox-regression model to predict long-term survival following resection. RESULTS: Pathological stage (P<0.0001), age (P=0.01) and low estimated postoperative FEV1% (P=0.0007) showed independent value to predict the outcome. CONCLUSION: Advanced age and low predicted postoperative FEV1% play an adverse effect on survival of completely resected NSCLC.     

Lumacaftor/Ivacaftor reduces pulmonary exacerbations in patients irrespective of initial changes in FEV1

Background

Improved lung function and fewer pulmonary exacerbations (PEx) were observed with lumacaftor/ivacaftor (LUM/IVA) in patients with cystic fibrosis homozygous for F508del. It is unknown whether PEx reduction extends to patients without early lung function improvement.

Changes of cervical spinal cord and cervical spinal canal with age in asymptomatic subjects

STUDY DESIGN: Prospective study on magnetic resonance imaging (MRI) and radiographic findings of the cervical spine. OBJECTIVE: To elucidate the age-related changes of the cervical spinal cord and the cervical spinal canal and the relationship between the spinal cord and the spinal canal in asymptomatic subjects using MRI and radiography. SETTING: Tokyo, Japan. METHODS: The transverse area of the cervical spinal cord and the ratio of the anteroposterior diameter to the transverse diameter (RAPT) were investigated, using MRI in 229 asymptomatic subjects. The sagittal spinal canal diameter and anteroposterior diameter of the cervical vertebral body were also measured on plain lateral radiographs. The canal body ratio (CBR), which was defined as the diameter of the spinal canal divided by that of the vertebral body, was calculated. RESULTS: The transverse spinal cord area correlated negatively with age. RAPT did not correlate with age. The CBR correlated negatively with age. The correlation between spinal cord area and CBR was significant but weak and the correlation between RAPT and CBR was not significant. CONCLUSION: The transverse area of the cervical spinal cord measured by MRI decreased with age, while RAPT remained unchanged. The bony spinal canal became narrower with age. The spinal cord area and the shapes of the spinal cord were independent from the spinal canal diameter in asymptomatic subjects. These facts should be considered when evaluating radiological findings in patients with cervical spinal disorders.