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: Since clinical signs of meningeal irritation in infants may be absent or misleading, the American Academy of Pediatrics in 1996 recommended that a lumbar puncture be performed in young children following a febrile seizure. Recent evidence supports a conservative approach in children who do not look ill at the time of the physician's assessment. Moreover, seizures as the presenting or sole symptom of bacterial meningitis are very rare.

Objectives: To assess physicians’ compliance with the Academy’s recommendations and to determine the incidence of meningitis among febrile seizure patients, including those who did not undergo the puncture.

Methods: We conducted a retrospective analysis of the number of punctures obtained in febrile seizure patients aged 6–24 months, focusing on the clinician's indications for performing the procedure and on the clinical course of children who did not undergo the puncture.

Results: Among 278 patients (84% simple febrile seizure), 52 (18.7%) underwent the procedure. It was performed in 38% of 45 complex febrile seizure cases and in 48% of 91 infants younger than 12 months of age. Aseptic meningitis occurred in two infants, both with post-ictal apathy. Bacterial meningitis was not found and in none of the patients who did not undergo the puncture was meningitis later diagnosed.

Conclusions: Compliance with the Academy’s recommendations was low, as emergency room physicians based their decision whether to obtain a lumbar puncture solely on clinical grounds. No case of bacterial meningitis was detected among 278 young children with a febrile seizure, including those who did not undergo the puncture.