Assessment of bronchial obstruction and its reversibility by shape indexes of the flow‐volume loop in asthmatic children

Asthma assessment by spirometry is challenging in children as forced expiratory volume in 1 s (FEV1) is frequently normal at baseline. Bronchodilator (BD) reversibility testing may reinforce asthma diagnosis but FEV1 sensitivity in children is controversial. Ventilation inhomogeneity, an early sign of airway obstruction, is described by the upward concavity of the descending limb of the forced expiratory flow‐volume loop (FVL), not detected by FEV1. The aim was to test the sensitivity and specificity of FVL shape indexes as β‐angle and forced expiratory flow at 50% of the forced vital capacity (FEF50)/peak expiratory flow (PEF) ratio, to identify asthmatics from healthy children in comparison to “usual” spirometric parameters. Seventy‐two school‐aged asthmatic children and 29 controls were prospectively included. Children performed forced spirometry at baseline and after BD inhalation. Parameters were expressed at baseline as z‐scores and BD reversibility as percentage of change reported to baseline value (Δ%). Receiver operating characteristic curves were generated and sensitivity and specificity at respective thresholds reported. Asthmatics presented significantly smaller zβ‐angle, zFEF50/PEF and zFEV1 (p ≤ .04) and higher BD reversibility, significant for Δ%FEF50/PEF (p = .02) with no difference for Δ%FEV1. zβ‐angle and zFEF50/PEF exhibited better sensitivity (0.58, respectively 0.60) than zFEV1 (0.50), and similar specificity (0.72). Δ%β‐angle showed higher sensitivity compared to Δ%FEV1 (0.72 vs. 0.42), but low specificity (0.52 vs. 0.86). Quantitative and qualitative assessment of FVL by adding shape indexes to spirometry interpretation may improve the ability to detect an airway obstruction, FEV1 reflecting more proximal while shape indexes peripheral bronchial obstruction.     

Cryosurgery for malignant endobronchial tumors: analysis of outcome

STUDY OBJECTIVES: More than 80% of patients with lung cancer are unsuitable for curative surgical treatment. Palliative relief of symptoms, often caused by airway obstruction, is very important. Endobronchial cryosurgery is used for destruction of intraluminal tumors. This study analyzes the effects of cryosurgery on patients with obstructive endobronchial carcinoma. DESIGN: Retrospective analysis of data extracted from a prospective computerized database. SETTING: Tertiary referral thoracic surgical center. PATIENTS: Data of the 172 patients who underwent at least two sessions of endobronchial cryosurgery (group A) were compared with 157 patients who underwent one session of cryosurgery (group B) for malignant primary or metastatic obstructive lung carcinoma over a 5-year period. INTERVENTION: Endobronchial cryosurgery is performed under general anesthesia. A nitrous oxide cryoprobe is inserted through a rigid bronchoscope. The probe achieves a temperature of - 70 degrees C at its tip and is applied to the tumor for two 3-min periods. Statistical analysis assessed the effects of cryosurgery on symptoms, lung function, Karnofsky performance score, and survival. RESULTS: Symptoms of dyspnea, cough, and hemoptysis were significantly reduced in both groups after cryosurgery (p < 0.001), although group A benefited more than group B. Lung function test results improved significantly in group A. The mean Karnofsky performance score (+/- SD) increased from 67 +/- 9 to 74 +/- 10 (group A) and from 67 +/- 10 to 73 +/- 11 (group B). The mean survival was 15 months (median, 11 months) for group A and 8.3 months (median, 6 months) for group B (p = 0.006). Univariate regression analysis showed that no particular patient or tumor characteristic was associated with reduction of symptoms. Patients who had cryosurgery and external beam radiotherapy showed longer survival (p < 0.01). Females and patients with stage IIIa and IIIb tumors achieved significantly improved Karnofsky scores (p < 0.02). Female sex was also a factor for increase in FEV at 1 min (p = 0.003) and FVC (p < 0.001). CONCLUSIONS: Cryosurgery is a safe method for palliation of endobronchial malignancies causing airway obstruction. Statistical analysis showed improvement of dyspnea, cough, and hemoptysis. Cryosurgery can be considered in patients with inoperable obstructive endobronchial carcinoma.