Table 2.
Measured and calculated densities of hypobaric LA-A solutions and difference from pure LA and calculated density. *—>0.0006; #—p < 0.05.
| Measured Density (g/mL) (±SD) | Pure LA Density—LA-A Measured Density (g/mL) | Calculated Density (p-Value) | Measured Density—Calculated Density | |
|---|---|---|---|---|
| CSF | 1.0003 (0.0003) |
|||
| Lidocaine (Lido) | 1.00011 (0.00002) |
|||
| Ropivacaine (Ropi) | 0.99966 (0.00009) |
|||
| Fentanyl | 0.99360 (0.00004) |
|||
| Morphine | 0.99993 (0.00003) |
|||
| 7.5 mg Ropi + 25 µg Fentanyl | 0.99824 (0.00011) |
0.00142 * |
0.99814 (0.016) |
0.00010 |
| 7.5 mg Ropi + 100 µg Morphine | 0.99975 (0.00005) |
−0.00009 |
0.99968 (0.001) # |
0.00008 |
| 15 mg Ropi + 25 µg Fentanyl | 0.99890 (0.00010) |
0.00076 * |
0.99879 (0.007) # |
0.00010 |
| 15 mg Ropi + 100 µg Morphine | 0.99970 (0.00005) |
−0.00004 |
0.99967 (0.11) |
0.00003 |
| 40 mg Lido + 25 µg Fentanyl | 0.99883 (0.00004) |
0.00128 * |
0.99881 (0.282) |
0.00002 |
| 40 mg Lido + 100 µg Morphine | 1.00002 (0.00004) |
0.00009 |
1.00010 (0.0001) # |
−0.00009 |
| 60 mg Lido + 25 µg Fentanyl | 0.99915 (0.00006) |
0.00096 * |
0.99918 (0.187) |
−0.00003 |
| 60 mg Lido + 100 µg Morphine | 0.99999 (0.00004) |
0.00012 |
1.00010 (0.00001) # |
−0.00011 |