Table 2.
Studies reporting oxygen desaturation
| Study (Year), country | Patients | Study outline | Results | Favors lateral | Notes |
|---|---|---|---|---|---|
| Preoperative adult patients | |||||
| Rosenberg-Adamsen et al. [30] (1997) Denmark | 13 patients scheduled for gastro-intestinal surgery | Descriptive sleep study of | • Mean average SpO2 (%): Supine: 95, lateral: 95 | ? | We have used preoperative values only (postoperative values may be confounded). |
| • Mean average SpO2 supine vs. lateral sleeping during preoperative night. | • Mean number of desaturation episodes/h: Supine: 13, lateral: 3 | + | Reports p = 0.04. | ||
| • Mean number of desaturations pr. hour, defined as sudden desaturation of more than 5% below the patient’s baseline value. | No difference in mean SpO2, but in number of desaturation episodes. | ||||
| Adults with obstructive sleep apnea | |||||
| Cao et al. [31] (2005) China | 225 adults with known obstructive sleep apnea (OSA) | Descriptive sleep study of nadir (lowest) SpO2 in lateral vs. supine sleeping position. Reports separately on positional patients (with a known position dependent OSA) and non-positional patients. | Nadir SpO2 (mean; %), | ? | p-values not given. |
| • Positional patients: Supine: 78.9, lateral: 79.5 | Very low values for both groups in both positions. | ||||
| • Non-positional patients: Supine: 71.5, lateral: 75.1 | + | ||||
| Shao et al. [32] (2011) China | 110 elderly patients with OSA | Descriptive sleep study of oxygen saturation in supine left and right sleeping positions, reporting time intervals between desaturation episodes (the latter not defined). | Time between desaturation episodes (median; min): Supine: 2.36, left side: 11.54, right side: 12.45 | + | Conference abstract only. |
| p < 0.01 for both left and right vs. supine. | |||||
| Oksenberg et al. [33] (2000) Israel | 30 adults with OSA | Descriptive sleep study, reporting | • Mean apnea duration + (sec): Supine: 26.6, lateral: 22.8 | + | p < 0.0001 |
| • apnea duration | • Mean minimum SpO2 (%): Supine: 82.0, lateral: 86.2 | + | Clinically relatively small differences. | ||
| • minimum oxygen desaturation | • Mean ∆ SpO2 (%): Supine: 12.6, lateral: 8.3 | + | |||
| • difference between max. and min. oxygen desaturation | |||||
| Sasai et al. [34] (2011) | 30 adults with OSA | Descriptive study of average SaO2 in supine vs. all sleeping positions. Reports data sorted by severity of OSA (moderate and severe). | Mean average SaO2 (%), supine vs. all: | ? | p < 0.01 and < 0.05, respectively, but at least in the severe OSA group the differences are not clinically important. |
| • Moderate OSA: Supine: 93.9, all positions: 95.1 | |||||
| • Severe OSA: Supine: 88.0, all positions: 88.4 | ? | ||||
| Browaldh et al. [35] (2013) Sweden | 64 OSA patients | Two groups, one treated surgically for OSA (1), the other just observed (2). Reports data on oxygen desaturation index (ODI; events/h) before treatment. | ODI (events/h): | + | p-values not given. Clinically important difference, may have been even larger if supine was not included in all positions. |
| • 1: Supine: 62.7, all positions: 44.6 | |||||
| • 2: Supine: 54.5, all positions: 41.1 | + | ||||