Radiofrequency Volumetric Tissue Reduction of the Palate in Subjects With Sleep-Disordered Breathing: RF Parameters Results

16 May
2014

Radiofrequency Volumetric Tissue Reduction of the Palate in Subjects With Sleep-Disordered Breathing: RF Parameters ResultsThe mean RFe delivered per treatment session was 688±106 J. The mean overall total number of joules per patient at the end of treatment was 2,377±869 J. The mean duration in seconds at a single treatment visit was 141 ±30 s. The mean total duration for an individual subject for all procedures combined was 500 ± 169 s. The mean of the joules for the individual paramedian (right and or left) was 199±91.5 J. The mean power delivery in watts was 4.99±1.9, and impedance was a mean of 145±25.7 ohms. The temperature in Celsius was a mean at the active electrode of 73.5± 16.9°, and at the junction of the active electrode and protective sheath, a mean of 46.6±9.6°. The protective sheath was 10 mm in length for all treatments and was found sufficient to spare the surface tissues of thermal damage when using the mean RF parameters above. buy zyrtec online

Polysomnography Results
Polysomnograms were performed at baseline, 48 to 72 h after the initial treatment, and 8 to 12 weeks following the last treatment. Table 2 summarizes the results of these tests. It also reports the results of repeated measures analyses of variance that compare mean values of key polysomno-graphic parameters at the three time points. The table indicates that at 48 to 72 h, patient status was significantly worse than at baseline when it was measured by RDI (p = 0.0007), apnea index (p<0.0001), hypopnea index (p = 0.006), minimum Sa02 (p = 0.0007), and normal awake Sa02 (p = 0.033). However, all of these values returned to baseline on the 10- to 12-week posttreatment polysomnogram. None of the polysomnographic parameters in Table 3 became worse after completion of treatment. The sleep efficiency index (SEI) was a parameter whose pretreatment value of 0.74±0.14 improved significantly to 0.82±0.09 (p = 0.006) at 48 to 72 h and 0.84±0.09 (p = 0.002) at 10 to 12 weeks posttreatment. The final point of note in Table 2 is that the pretreatment mean inspiratory negative Pes nadir of — 27.8± 11.9 cm H20 was significantly reduced to —21.8± 11.9 cm H20 (p = 0.031) on the posttreatment assessment. Only two subjects, both with UARS, had a pretreatment Pes of —19 and —13 cm H20, respectively, which was reduced posttreatment to a Pes of —5 cm H20. These pressures represent the most negative pressures nadir during nocturnal sleep. A more detailed representation is reflected by the mean of the 95th percentile of the Pes values. These data were determined from the recording of a mean of 5,522 breaths during nocturnal sleep (range, 4,372 to 6,316). The results were as follows: the pretreatment mean 95th percentile inspiratory pressure nadir was -19.71±5.29 cm H20 (range, 14.1 to 30.4) and posttreatment was -12.78±6.28 cm H20 (range, 7.6 to 30.0) (p = 0.0001).
Table 2—Changes in Polysomnographic Parameters

p Values
VariablePre-Tx48-72 h Post 1st Tx10-12 wk Post-TxPre-Vs 48-72 hPre-Vs 10-12 wk48-72 h vs 10-12 wk
RDI3.93 ±3.310.5 ±9.13.4 ±3.10.00070.548<0.0001
AI0.88±2.54.45±5.90.55 ±1.1<0.00010.628<0.0001
HI3.05±2.56.01±4.42.84±2.40.0060.5430.001
SEI0.74±0.140.82±0.090.84±0.090.0060.0020.636
L-SAT91.2±4.686.5 ±6.391.5±3.20.00070.7620.0003
Base SAT95.7±2.194.1±2.496.2±2.30.0330.4080.004
% REM14.0±6.115.7±6.514.3±7.10.3370.8640.429
Pes (nadir)27.8±11.929.5 ±22.121.8±11.90.8960.0310.559
Pes 95th %’ 19.71±5.29(n=19)Not done (n= 11) 12.78±6.28(n=17)<0.0001
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