Monitoring fluctuations in nasal patency in children: acoustic rhinometry versus rhinohygrometry.

Simple rhinohygrometry and passive rhinomanometry studies have suggested that the 'nasal cycle' in children is often different in pattern of that of adults and experimental animals. We aimed to establish whether this assertion was correct, using a reliable and sensitive method, acoustic rhinometry (AR), and to compare results with those of simple rhinohygrometry (RH). Healthy children with no evidence of nasal disease were examined (n = 15; age range three to 10 years; mean age six years). Simultaneous recordings using AR and RH were made on each child every 10-15 minutes over two to four hour periods. Six children underwent nine additional AR studies on separate occasions. 'Classical' reciprocal alternating patterns were evident in 80 per cent (12/15) AR and 53 per cent (8/15) RH studies, 'in concert' patterns in seven per cent (1/15) AR and 20 per cent (3/15) RH studies and 'irregular' patterns in 13 per cent (2/15) AR and 27 per cent (4/15) RH studies. The agreement between the two methods was 47 per cent, with a kappa (kappa) value of -0.17 (poor agreement compared to chance). Agreements between the acoustic rhinometry parameters were 'fair' for all data (kappa = 0.34) and excellent (kappa = 1.0) if irregular patterns were ignored. Repeated studies showed that the pattern of fluctuation varies within any particular individual. The nasal cycle is similar in pattern in children and adults, and acoustic rhinometry is currently the method of choice to further investigate and clarify this phenomenon.