Expiratory Airflow Patterns in Children and Adults With Cystic Fibrosis

Williams, Edgar M.; Madgwick, Richard G.; Thomson, Anne; Morris, MJ

doi:10.1378/chest.117.4.1078

Cited by 15 publications

(21 citation statements)

References 16 publications

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“…Subsequent studies have demonstrated that a shortened ratio may also be associated with lower airway obstruction in children and infants. A significant, albeit weak, relationship has been observed between TPTEF:TE and forced expiratory volume in one second in subjects with CF aged 6-36 yrs [32]. Similarly, VAN DER ENT et al [26] found that, amongst children aged 3-11 yrs, TPTEF:TE not only correlated with spirometric parameters, but increased following bronchodilator therapy in those with asthma.…”

Section: Discussionmentioning

confidence: 95%

Assessment of tidal breathing parameters in infants with cystic fibrosis

Ranganathan¹,

Goetz²,

Hoo³

et al. 2003

Eur Respir J

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Simple methods are needed to assess lung function in infants with cystic fibrosis (CF). This study determined the relationship between simple measurements obtained from tidal breathing with those from more complicated forced expiratory manoeuvres.Healthy infants and infants with CF were recruited from two maternity units and five specialist CF hospitals, respectively. Respiratory rate, tidal volume, minute ventilation and the tidal breathing ratio (TPTEF:TE) were measured in sedated infants and compared with forced expiratory volume in 0.4 seconds (FEV0.4) measured by the raised volume technique.Altogether, 95 healthy infants and 47 infants with CF of similar age, sex, ethnicity and proportion exposed to maternal smoking were recruited. There was no difference in TPTEF:TE and tidal volume between healthy infants and those with CF. Minute ventilation was significantly greater in infants with CF due to a mean (95% confidence interval) increase in respiratory rate of 5.8 (3.2-8.4) min -1 . Thirteen (28%) infants with CF had a respiratory rate elevated by w2 SD. However, no association between respiratory rate and FEV0.4 could be identified.Tidal breathing ratio was not useful in identifying diminished airway function in infants with cystic fibrosis. An elevated respiratory rate may be due in part to ventilation heterogeneity but is poorly predictive of diminished airway function measured by forced expiration. Eur Respir J 2003; 22: 761-766.

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Section: Discussionmentioning

confidence: 95%

Assessment of tidal breathing parameters in infants with cystic fibrosis

Ranganathan¹,

Goetz²,

Hoo³

et al. 2003

Eur Respir J

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“…On the other hand, assessment of the spontaneous expiratory flow-volume (SEFV) curve has been reported as a method to evaluate the severity of airway obstruction, which has the advantage that it is easily measured via spirometry during quiet breathing. [3][4][5][6][7][8][9][10] Shortening of the time to reach the peak expiratory flow 3 and the slope of the late SEFV curve, 4 which can be obtained from the SEFV curve, has been reported to be related to airway obstruction. Moreover, a method to assess the pattern of the SEFV curve has been reported, and concavity of the SEFV curve has been found to be related to expiratory flow limitation.…”

Section: Introductionmentioning

confidence: 99%

Relationship Between Spontaneous Expiratory Flow-Volume Curve Pattern and Air-Flow Obstruction in Elderly COPD Patients

Nozoe¹,

Mase

Murakami³

et al. 2013

Respir Care

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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 airflow 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.

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“…These increased loads would provide a significant stimulus to the respiratory muscles which when combined with the effects of AAS could result in significant improvements in the strength of these muscles so that they may better cope with the increased loads associated with COPD. Tidal flow-time patterns in expiration are different in normal subjects from those seen in patients with severe airways obstruction (Williams et al, 2000). Indices of the shape of the expiratory flow-time tracing have been described and developed to help in assessment of airways obstruction.…”

Section: Discussionmentioning

confidence: 99%

“…An unchanged expiratory flow profile also illustrates that despite the inspiratory muscles being stronger, they do not alter airway tone or resistance. If, for instance, there were more postinspiratory flow braking, then more convex patterns would be seen (Williams et al, 2000; Figure 2). Differences in grip strength between the four groups followed the same pattern as MIP; i.e., grip strength was significantly greater in SU compared with SC, but there was no difference between the other groups.…”

Section: Discussionmentioning

confidence: 99%

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Effects of Long-Term Anabolic Androgenic Steroid Administration on Respiratory Function

Gething

Grace

Davies

et al. 2011

Research in Sports Medicine

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The purpose of this study was to investigate the effects of resistance training and long-term anabolic androgenic steroids (AASs) administration on respiratory function. Subject groups consisted of AAS users (n = 9) who were still using AAS at time of testing (SU); AAS users (n = 6) who had been abstinent for > 3 months (SA), bodybuilding controls (n = 8) (BC), and (n = 8) sedentary male controls (SC). FEV(1), FVC, and PEF were measured. The results found that all subjects were within normal range, and there were no differences between groups. Maximum inspiratory pressure (MIP), and grip strength were both significantly greater in SU (P < 0.05) compared with SC; no significant difference was found between the other groups. Their MIP and grip strength was significantly correlated (r = 0.57; P < 0.05). The data from this study suggest that the combination of resistance training and AAS administration produce a significant increase in MIP in a cohort of long-term AAS users.

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Expiratory Airflow Patterns in Children and Adults With Cystic Fibrosis

Cited by 15 publications

References 16 publications

Assessment of tidal breathing parameters in infants with cystic fibrosis

Assessment of tidal breathing parameters in infants with cystic fibrosis

Relationship Between Spontaneous Expiratory Flow-Volume Curve Pattern and Air-Flow Obstruction in Elderly COPD Patients

Effects of Long-Term Anabolic Androgenic Steroid Administration on Respiratory Function

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