A third forced spirometry blow is unnecessary in some patients say researchers whose study findings challenge existing guidelines.
The study of 49 cystic fibrosis patients and 64 lung transplant patients compared the best FEV1 measurement from trials 1 and 2 with trial 3 and calculated the difference in litres and % predicted.
The researchers from the Prince Charles Hospital in Brisbane found 63% of the CF patients and 73% of the transplant patients performed better on trials one and two.
No significant link was found between the visit number and difference between blows.
“A third spirometry manoeuvre does not provide additional clinical information in specific groups of patients and may prove unnecessary in carefully selected patient groups,” they concluded.
However the researchers did acknowledge limitations such as their patient population was younger than the average patient seen in a respiratory lab, were highly motivated and understood the implications of lower measurements.