Table 1.

The patient test

	Humid-Heat	Fisher & Paykel MR730	P
Duration of the test (h)	24 ± 0.5	22± 4.0	0.27
Change in the patient's body temperature (°C)	-0.28 ± 0.36	+0.01 ± 1.1	0.56
Change in the temperature at the Y-piece or the flex-tube (°C)	-0.13 ± 0.64	0.0 ± 0.54	0.71
Suctions (n)	10.4 ± 3.9	9.2 ± 3.2	0.75
Saline instillations (n)	5.9 ± 3.1	4.6 ± 2.9	0.43
Total volume of saline instilled (ml)	30 ± 20	24 ± 23	0.41
No of nebulizations (salbutamol 2.5 mg plus 200 mg N-acetylcystein	3.6 ± 1.8	3.9 ± 2.0	0.75
diluted with saline to a total of 5 ml)
Quality of secretions at the start of the experiment (thick, normal, thin) (n)	thick 2, normal 2, thin 4	thick 4, normal 3, thin 1	0.26
Quality of secretions at the end of the experiment, patients (n)	thick 0, normal 5, thin 3	thick 1, normal 5, thin 2	0.18
Change in thickness of secretions (i = increase, d = decrease,	d = 3, i = 3, O = 2	D = 3, i = 1, O = 4	0.44
O = no change), patients (n)
Change in airway pressure at a prolonged expiratory pause	0	0	0.99
Water consumed/h (ml)	5.6 ± 1.2	30 ± 15	0.0008
Water consumed/l inspired gas (ml)	0.009 ± 0.003	0.043 ± 0.018	0.0008
Number of times that the water traps were emptied	0	8.3 ± 3.2	0.0008
Total amount of fluid in the water traps (ml)	0	213 ± 84	0.0008
Number of changes of machine filters due to excessive water condensation	0	4.7 ± 1.6	0.0008

The numbers are presented as mean ± standard deviation when applicable.