RELIABILITY OF CLINICAL ASSESSMENTS OF RESPIRATORY SYSTEM COMPLIANCE (CRS) MADE BY JUNIOR DOCTORS

Objective: To assess the reliability of estimates of static respirator y system compliance (Crs) made by junior hospital doctors caring for v entilated newborn infants. Design: A prospective comparison of junior doctors' estimates of Crs to the Crs measured immediately afterwards. Setting: A regional neonatal intensive care nursery in Edinburgh, Scot land. Patients: 46 ventilated newborn infants. Measurements and result s: Crs was estimated by three grades of junior doctor (Senior House Of ficer, Registrar and Research Fellow) using two different methods, (i) based on visual assessment of tidal volume in relation to inflation p ressure (optimal Crs) and (ii) directly using a visual analogue scale (analogue Crs). The Crs was then measured immediately afterwards using the single breath passive expiratory flow technique. The differences between the estimates and the measurements were calculated for each gr ade of observer and plotted against the corresponding measurements. Th e relationship between estimates and measurements was also expressed i n terms of the coefficients of determination r2 calcualted by least sq uares regression. With both methods of estimation observers tended to overestimate the Crs of infants with lower measured Crs and underestim ate that of infants with higher measured Crs with many estimates diffe ring from the measurements by more than 50%. Values of r2 ranged from 0.086 to 0.481 indicating a weak relationship between the estimates an d the measurements. Conclusions: Junior doctors' estimates of Crs were unreliable and did not represent a useful method of assessing respira tory function. The clinical use of compliance measurements merits wide r evaluation.