Israel Medical Association Journal

Background: The single-breath diffusing capacity of the lungs (DLCO_SB) test measures the extent to which carbon monoxide (CO) passes from the lung air sacs into the blood. The accessible alveolar volume (VA_SB) is measured by inert gas during a 10-second period. The single-breath transfer coefficient of the lung for carbon monoxide (KCO_SB) is the DLCO_SB divided by VA_SB. Cystic fibrosis (CF) disease comprises progressive airway obstruction with bronchiectasis and parenchyma fibrosis. Yet, the KCO_SB appears insignificant in the assessment of pulmonary function in CF.

Objectives: To challenge the precision of normal KCO_SB in CF.

Methods: The authors collected pulmonary function tests (PFT) data from 74 confirmed CF patients (mean age 26 ± 10 years) with various levels of pulmonary disease severity. Tests included spirometry, DLCO_BP, and body plethysmography (_BP). Anatomical dead space was calculated by deducting anatomical dead space from total lung capacity TLC(_BP) to establish alveolar volume (VA_BP) and to determine KCO_BP. We also included individual data of arterial pCO₂ blood-gas level.  

Results: KCO_SB values were normal or higher in most patients, regardless of patient FEV1 value (R² = 0.2204; P < 0.02). In contrast, the measurements of KCO_BP were low corresponding with low FEV1 values, and negatively correlated with the elevation of trapped air and pCO₂ levels (R² = 0.1383; P = 0.0133, P > 0.05, respectively).

Conclusions: The 10- second perfusion time of the inert gas during DLCO_SB represent the communicative alveolar volume in CF patients with advanced pulmonary disease. The findings justify the use of DLCO_SB with the deterioration of FEV1 and elevation of pCO₂ levels.

Background: In infants, small volume nebulizers with a face mask are commonly used to facilitate aerosol therapy. However, infants may be disturbed by mask application, causing poor mask-to-face seal and thus reducing the dose delivered.

Objectives: To compare lung function response to bronchodilator nebulization via two delivery devices: hood versus mask.

Methods: We studied 26 recurrently wheezy infants aged 45.8 weeks (95% confidence interval 39.6–52.0). Inhalations of 0.30 mg/kg salbutamol were administered in two alliqots 30 minutes apart using mask and hood in alternating order (M+H or H+M). Response to inhalations was measured by maximal expiratory flows at functional residual capacity at 5 minute intervals after each dose, and area under the VmaxFRC[1] curve was documented.

Results: A small but significant response to salbutamol was observed following the second inhalation with VmaxFRC, improving by 31.7% (7.2–56.2, P < 0.02) and AUC[2] by 425 %•min (-154, 1004; P < 0.02). The improvement following salbutamol was similar by both delivery modalities but with a small but significantly better response when H was used after M (P < 0.01).

Conclusions: Nebulized salbutamol induced a variable but positive response in wheezy infants. Salbutamol via hood was as effective as conventional face mask delivery. Since it is simple and patient-friendly, it could replace the face mask method particularly with uncooperative infants.

Background: Blunt chest trauma can cause severe acute pulmonary dysfunction due to hemo/pneumothorax, rib fractures and lung contusion.

Objectives: To study the long-term effects on lung function tests after patients' recovery from severe chest trauma.

Methods: We investigated the outcome and lung function tests in 13 patients with severe blunt chest trauma and lung contusion.

Results: The study group comprised 9 men and 4 women with an average age of 44.6 ± 13 years (median 45 years). Ten had been injured in motor vehicle accidents and 3 had fallen from a height. In addition to lung contusion most of them had fractures of more than three ribs and hemo/pneumothorax. Ten patients were treated with chest drains. Mean intensive care unit stay was 11 days (median 3) and mechanical ventilation 19 (0–60) days. Ten patients had other concomitant injuries. Mean forced expiratory volume in the first second was 81.2 ± 15.3%, mean forced vital capacity was 85 ± 13%, residual volume was 143 ± 33.4%, total lung capacity was 101 ± 14% and carbon monoxide diffusion capacity 87 ± 24. Post-exercise oxygen saturation was normal in all patients (97 ± 1.5%), and mean oxygen consumption max/kg was 18 ± 4.3 ml/kg/min (60.2 ± 15%). FEV1[1]. was significantly lower among smokers (71.1 ± 12.2 vs. 89.2 ± 13.6%, P = 0.017). There was a non-significant tendency towards lower FEV1 among patients who underwent mechanical ventilation.

Conclusions: Late after severe trauma involving lung contusion, substantial recovery is demonstrated with improved pulmonary function tests. These results encourage maximal intensive care in these patients. Further larger studies are required to investigate different factors affecting prognosis.

Background: Since surgical repair of tetralogy of Fallot was introduced, follow-up studies have shown that the majority of patients lead actives lives and have no subjective exercise limitation.

Objectives: To examine lung function, cardiopulmonary functional capacity and echo-Doppler assessment of pulmonary pressure in adult patients 20 years after repair of TOF.

Methods: Unselected consecutive patients performed full lung function testing, progressive cardiopulmonary exercise, and echo-Doppler assessments of pulmonary pressure.

Results: Fifty consecutive patients (33 men, 17 women) aged 29 ± 11 years who underwent surgical repair of TOF at age 10.1 ± 10.9 years were enrolled in this study. Patients after TOF showed no restriction (forced expiratory vital capacity 80%, total lung capacity 91%) and had normal oxygen saturation (97%) and 6 minute walking distance (600 meters). Echocardiography showed normal pulmonary pressure and left ventricular ejection function (62%). Cardiopulmonary exercise testing showed mild limitation of exercise capacity with oxygen uptake at maximal effort of 75–78% predicted.

Conclusions: After corrections of TOF the study patients had normal lung function and pulmonary arterial pressure but mild limitation in their exercise capacity.