The relationship between volumetric capnography and the severity of chronic obstructive pulmonary disease / 中华老年医学杂志

Objective To explore the correlation between volumetric capnography(VCap)and traditional pulmonary function in chronic obstructive pulmonary disease(COPD),so as to assess whether VCap can be used as alternative indicators for the evaluation of COPD severity when some of the elderly COPD patients do not accomplish the traditional pulmonary function tests.Methods 960 patients admitted to Fujian Geriatric Hospital from June 2008 to June 2015 and undergoing pulmonary function tests were included in the study.They were divided into 2 groups of the COPD group(640 cases)and the control group(320 cases).The pulmonary function of COPD group was divided into 4 subgroups(Ⅰ~Ⅳ).All persons received tests of traditional pulmonary function and VCap.The correlations between VCap and traditional pulmonary function indexes and between VCap and COPD severity were observed.Results The differences in Vm25-50/VT,Vm50-75/VT,dC/dV3,SR23 of VCap between the 4 subgroups(COPDⅠ~COPDⅣ)and control group were statistically significant(all P0.05).The difference in CO2 max between the COPD Ⅲ group(severe or more severe group)and control group was statistically significant(t=6.91 and 4.65,all P0.555,P<0.05).The specificity of Vm25-50/VT of VCap for the diagnosis of COPD was best,but its sensitivity was poor than other indexes of VCap.The indexes with both high sensitivity and high specificity were Vm50-75/VT and dC/dV3.Conclusions When the patients with COPD manifest the mild airflow limited,Vm25-50/VT,Vm50-75/VT,dC/dV3 and SR23 of VCap are gradually increased with abnormal VCap figures when the illness progressed.The CO2max of VCap might be one of the indexes for assessing the severity of severe or more severe COPD.

Evaluación de flujos y volúmenes dinámicos en pacientes con compromiso muscular respiratorio / Dynamic flows and volumes evaluation in patients with respiratory muscle impairment

Spirometry measures the forced expiratory volumes and flows. In patients with neuromuscular disease, these are altered since there is some respiratory muscle involvement. The usefulness of this test is based on the interpretation of the shape of the flow / volume loop and values of spirometric variables. In patients with neuromuscular disease, Forced Vital Capacity is the most used especially for its prognosis value.

La espirometría mide volúmenes y flujos espiratorios forzados. En los pacientes con enfermedad neuromuscular (ENM) estos se ven alterados debido al compromiso muscular respiratorio. La utilidad de este examen se basa en la interpretación de la forma de la curva flujo/volumen y los valores de las variables espirométricas. En los pacientes con ENM la Capacidad Vital Forzada es la más utilizada ya que otorga valor pronóstico.

Changes in the Flow-Volume Curve According to the Degree of Stenosis in Patients With Unilateral Main Bronchial Stenosis

OBJECTIVES: The shape of the flow-volume (F-V) curve is known to change to showing a prominent plateau as stenosis progresses in patients with tracheal stenosis. However, no study has evaluated changes in the F-V curve according to the degree of bronchial stenosis in patients with unilateral main bronchial stenosis. METHODS: We performed an analysis of F-V curves in 29 patients with unilateral bronchial stenosis with the aid of a graphic digitizer between January 2005 and December 2011. RESULTS: The primary diseases causing unilateral main bronchial stenosis were endobronchial tuberculosis (86%), followed by benign bronchial tumor (10%), and carcinoid (3%). All unilateral main bronchial stenoses were classified into one of five grades (I, 90% to near-complete obstruction without ipsilateral lung collapse). A monophasic F-V curve was observed in patients with grade I stenosis and biphasic curves were observed for grade II-IV stenosis. Both monophasic (81%) and biphasic shapes (18%) were observed in grade V stenosis. After standardization of the biphasic shape of the F-V curve, the breakpoints of the biphasic curve moved in the direction of high volume (x-axis) and low flow (y-axis) according to the progression of stenosis. CONCLUSION: In unilateral bronchial stenosis, a biphasic F-V curve appeared when bronchial stenosis was >25% and disappeared when obstruction was near complete. In addition, the breakpoint moved in the direction of high volume and low flow with the progression of stenosis.

Fisiología de la curva flujo/volumen espirométrica / Flow-volume curve: its physiological basis

We describe physiological basis to explain flow/volume curve obtained by forced spirometry. The main factors involved are alveolar and intraluminal airway pressure and transthoracic pressure, whose interrelationship determines dynamic airway compression. Lung and thoracic elastic recoil pressure and lung volumes also participate.

Se describen las bases fisiológicas de la curva flujo/volumen obtenida mediante espirometría forzada. Los principales factores involucrados son la presión alveolar y de la vía aérea y la presión transtorácica, cuyo balance determina la compresión dinámica de la vía aérea. Además intervienen la presión de retracción elástica pulmonar y de la caja torácica y los volúmenes pulmonares.

Contribution of flow-volume curves to the detection of central airway obstruction / Contribuicao da curva de fluxo-volume na deteccao de obstrucao da via aerea central

OBJECTIVE: To assess the sensitivity and specificity of flow-volume curves in detecting central airway obstruction (CAO), and to determine whether their quantitative and qualitative criteria are associated with the location, type and degree of obstruction. METHODS: Over a four-month period, we consecutively evaluated patients with bronchoscopy indicated. Over a one-week period, all patients underwent clinical evaluation, flow-volume curve, bronchoscopy, and completed a dyspnea scale. Four reviewers, blinded to quantitative and clinical data, and bronchoscopy results, classified the morphology of the curves. A fifth reviewer determined the morphological criteria, as well as the quantitative criteria. RESULTS: We studied 82 patients, 36 (44%) of whom had CAO. The sensitivity and specificity of the flow-volume curves in detecting CAO were, respectively, 88.9% and 91.3% (quantitative criteria) and 30.6% and 93.5% (qualitative criteria). The most prevalent quantitative criteria in our sample were FEF50%/FIF50% ≥ 1, in 83% of patients, and FEV1/PEF ≥ 8 mL . L–1 . min–1, in 36%, both being associated with the type, location, and degree of obstruction (p < 0.05). There was concordance among the reviewers as to the presence of CAO. There is a relationship between the degree of obstruction and dyspnea. CONCLUSIONS: The quantitative criteria should always be calculated for flow-volume curves in order to detect CAO, because of the low sensitivity of the qualitative criteria. Both FEF50%/FIF50% ≥ 1 and FEV1/PEF ≥ 8 mL . L–1 . min–1 were associated with the location, type and degree of obstruction. .

OBJETIVO: Verificar a sensibilidade e especificidade das curvas de fluxo-volume na detecção de obstrução da via aérea central (OVAC), e se os critérios qualitativos e quantitativos da curva se relacionam com a localização, o tipo e o grau de obstrução. MÉTODOS: Durante quatro meses foram selecionados, consecutivamente, indivíduos com indicação para broncoscopia. Todos efetuaram avaliação clínica, preenchimento de escala de dispneia, curva de fluxo-volume e broncoscopia num intervalo de uma semana. Quatro revisores classificaram a morfologia da curva sem conhecimento dos dados quantitativos, clínicos e broncoscopicos. Um quinto revisor averiguou os critérios morfológicos e quantitativos. RESULTADOS: Foram incluídos 82 doentes, 36 (44%) com OVAC. A sensibilidade e especificidade da curva de fluxo-volume na detecção de OVAC foram, respectivamente, de 88,9% e 91,3% (critérios quantitativos) e de 30,6% e 93,5% (critérios qualitativos). Os critérios quantitativos mais frequentes na amostra foram o FEF50%/FIF50% ≥ 1 em 83% e o VEF1/PFE ≥ 8 mL . L–1 . min–1 em 36% dos doentes, e ambos se relacionaram com o tipo, a localização e o grau de obstrução (p < 0,05). Houve concordância dos revisores quanto à existência ou não de OVAC. Existe relação entre o grau de obstrução e o de dispneia. CONCLUSÕES: Os critérios quantitativos devem ser sempre calculados nas curvas de fluxo-volume de forma a detectar OVAC, dado a baixa sensibilidade dos critérios qualitativos. Os critérios FEF50%/FIF50% ...

Padrões ventilatórios na espirometria em pacientes adolescentes e adultos com fibrose cística / Respiratory patterns in spirometric tests of adolescents and adults with cystic fibrosis

OBJETIVO: Avaliar os padrões dos distúrbios ventilatórios observados na espirometria em pacientes com fibrose cística (FC) e suas relações com a gravidade funcional e com o comportamento dos fluxos máximos expiratórios a baixos volumes. MÉTODOS: Estudo transversal e retrospectivo, incluindo pacientes adolescentes e adultos com FC. Todos os pacientes foram submetidos à espirometria. Os pacientes foram classificados como tendo função ventilatória preservada, distúrbio ventilatório obstrutivo (DVO), DVO com CVF reduzida, sugestivo de distúrbio ventilatório restritivo (DVR) ou distúrbio ventilatório combinado (DVC). Os fluxos máximos expiratórios a baixos volumes foram avaliados utilizando-se FEF25-75 por cento, FEF75 por centoe FEF75 por cento/CVF. O grupo controle incluiu 65 indivíduos normais, também submetidos à espirometria. RESULTADOS: Foram incluídos 65 pacientes no grupo de estudo: 8 (12,3 por cento) com função pulmonar preservada, 18 (27,7 por cento) com DVO, 24 (36,9 por cento) com DVO com CVF reduzida, 5 (7,7 por cento) com padrão sugestivo de DVR e 10 (15,4 por cento) com DVC. O VEF1 foi significativamente menor nos grupos DVO com CVF reduzida e DVC, comparados com os outros grupos (p < 0,001). Nos pacientes com função ventilatória preservada, FEF25-75 por cento e FEF75 por cento foram significativamente reduzidos em 1 paciente, assim como FEF75 por cento/CVF em 2 pacientes. CONCLUSÕES: O padrão ventilatório estava alterado em 88 por cento dos pacientes com FC. O distúrbio mais frequente foi DVO com CVF reduzida. Houve maior prejuízo funcional nos pacientes com DVO e CVF reduzida e com DVC. Os fluxos expiratórios máximos a baixos volumes foram alterados em uma pequena percentagem de pacientes com função pulmonar preservada.

OBJECTIVE: To evaluate spirometric patterns of respiratory disorders and their relationship with functional severity and maximal expiratory flows at low lung volumes in patients with cystic fibrosis (CF). METHODS: A retrospective cross-sectional study including adolescents and adults with CF. All of the patients were submitted to spirometry. Patients were classified as having preserved respiratory function, obstructive lung disease (OLD), OLD with reduced FVC, presumptive restrictive lung disease (RLD) or mixed obstructive and restrictive lung disease (MORLD). Maximal expiratory flows at low lung volumes were assessed using FEF25-75 percent, FEF75 percent and FEF75 percent/FVC. We included 65 normal subjects, also submitted to spirometry, as a control group. RESULTS: The study group included 65 patients: 8 (12.3 percent) with preserved lung function; 18 (27.7 percent) with OLD; 24 (36.9 percent) with OLD and reduced FVC; 5 (7.7 percent) with presumptive RLD; and 10 (15.4 percent) with MORLD. The FEV1 was significantly lower in the OLD with reduced FVC group and the MORLD group than in the other groups (p < 0.001). In the patients with preserved respiratory function, FEF25-75 percent and FEF75 percent were significantly reduced in 1 patient, as was FEF75 percent/FVC in 2 patients. CONCLUSIONS: The respiratory pattern was impaired in 88 percent of the patients with CF. The most common pattern was OLD with reduced FVC. The degree of functional impairment was greater in the OLD with reduced FVC group and in the MORLD group than in the other groups. Maximal expiratory flows at low lung volumes were impaired in a low percentage of patients with preserved respiratory function.