Table 2. Effect of nasal surgery on the effective CPAP in patients with OSA.

Author (reference)	No	CPAP pre (cm H2O)	CPAP post (cm H2O)	p-value
Mayer-Brix et al. 1989 (e31)	3	9.7	6	None
Friedman et al. 2000 (e32)	6	9.3	6.7	<0.05
Dorn et al. 2001 (e33)	5	11.8	8.6	<0.05
Masdon et al. 2004 (e34)	35	9.7	8.9	n. s.
Nakata et al. 2005 (e35)	5	16.8	12	<0.05
Zonato et al. 2006 (e36)	17	12.4	10.2	<0.001
Total	71	11	9.1

CPAP, continuous positive airway pressure ; pre, preoperatively; post, postoperatively; OSA, obstructive sleep apnea; n.s., non-significant