Table 2. Diaphragmatic ultrasound to measure diaphragmatic mobility and thickness in healthy subjects.
| Reference | n | Patient positioning Probe placement Probe orientation |
Measure | Reference values |
|---|---|---|---|---|
| Harris et al. 33 | 50 | Supine Subcostal MCL and longitudinal |
Mobility DB |
Anterior third: 4.0 ± 1.6 cm Middle and posterior third: 4.8 ± 1.6 cm 4.0 ± 1.2 cm (F); 5.4 ± 1.7 cm (M) |
| Gerscovich et al. 36 | 23 | Supine Longitudinal semi-coronal Subcostal or low intercostal between MCL and MAL |
Mobility QB |
Right hemidiaphragm - QB: 1.5 cm; DB: 5.7 cm; VS: 1.7 cm Left hemidiaphragm - QB: 1.6 cm; DB: 6.7 cm; VS: 1.8 cm |
| Kantarci et al. 39 | 160 | Supine Coronal plane Low anterior intercostal, subcostal, or both |
Mobility DB |
DB Right: 4.7 ± 1.0 (F) vs. 5.3 ± 1.1 cm (M) Left: 4.8 ± 0.3 (F) vs. 5.4 ± 1.3 cm (F) |
| Boussuges et al. 8 | 210 | Standing Right subcostal between MCL and AAL Left lower intercostal spaces or subcostal, between AAL and MAL |
Mobility QB DB |
QB - Right: 1.6 ± 0.3 cm (F); 1.8 ± 0.3 cm (M) - Left: 1.6 ± 0.4 cm (F); 1.8 ± 0.4 cm (M) DB - Right: 5.7 ± 1.0 cm (F); 7.0 ± 1.1 cm (M) - Left: 6.4 ± 1.0 cm (F); 7.5 ± 0.9 cm (M) VS - Right: 2.6 ± 0.5 cm (F); 2.9 ± 0.6 cm (M) - Left: 2.7 ± 0.5 cm (F); 3.1 ± 0.6 cm (M) |
| Testa et al. 9 | 40 | Supine, semi-recumbent 45° Subcostal anterior at MCL Probe is orientated transversely and directed cranially |
Mobility QB DB |
QB - Experienced operator: 1.8 ± 0.8 cm - Inexperienced operator 2.2 ± 0.9 cm DB - Experienced operator 6.9 ± 1.4 cm - Inexperienced operator 7.9 ± 1.3 cm |
| Ueki et al. 27 | 13 | Sitting ZOA |
Thickness | Tdi-exp: 1.7 ± 0.2 mm Tdi-insp: 4.5 ± 0.9 mm |
| Baldwin et al. 10 | 13 | Semi-recumbent 45° ZOA, ninth intercostal space |
Thickness Tdi-exp |
Tdi-exp: 1.7 [1.1-3.0] mm |
| Boon et al. 25 | 150 | Supine eighth or ninth intercostal space, immediately anterior to the AAL |
Thickness Tdi-exp Thickening ratio |
Tdi-exp: 2.7 ± 1 mm (F); 3.8 ± 1.5 mm (M) - LLN Tdi-exp: 1.4-1.7 mm - LLN thickening ratio: 1.2-1.3% |
| Carrillo-Esper et al. 29 | 109 | Supine ZOA, at FRC |
Thickness Tdi-exp |
Tdi-exp: 1.6 ± 0.4 mm 1.4 ± 0.3 mm (F); 1.9 ± 0.4 mm(M) |
| Cardenas et al. 24 | 64 | Semi-recumbent 45° Mobility: right anterior, subcostal region Diaphragm thickness: ZOA between AAL and MAL, at FRC and at TLC |
Mobility QB DB Thickness Tdi-exp Tdi-insp TF |
Mobility QB: 1.5 ± 0.4 cm DB: 6.41 ± 1.02 cm (F); 7.79 ± 0.82 cm (M) LLN DB mobility: 4.37 cm (F); 6.15 cm (M) Tdi-exp: 1.9 ± 0.3 mm (M) LLN at FRC: 1.2 mm (F); 1.3 mm (M) Tdi-insp: 4.81 ± 0.95 mm (F); 5.6 ± 0.9 mm (M) TF: 169 ± 43% (F); 204 ± 61% (M) |
MCL: midclavicular line; DB: deep breathing; F: female; M: male; MAL: midaxillary line; QB: quiet breathing; VS: voluntary sniff; AAL: anterior axillary line; ZOA: zone of apposition; Tdi-exp: diaphragm thickness at end-expiration; Tdi-insp: diaphragm thickness at end-inspiration; LLN: lower limit of normal; FRC: functional residual capacity; and TF: thickening fraction.