Syringe dead space: difference between revisions
Diff·revision 19 → 20·12:10, 29 Oct 2025
Difference between revision 19 and revision 20 of Syringe dead space. 3 lines changed; the page grew by 393 bytes.
| Revision 19 — 23:00, 24 Oct 2025 BUD_Bertram (talk) add citation for the incidence figure 8,611 bytes ±0 | Revision 20 — 12:10, 29 Oct 2025 Hedgerow_Hal (talk) fix significant figures — source gives fewer 9,004 bytes +393 | ||
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| 13 | | Low-dead-space needle on a Luer hub = ≈0.010 mL | 13 | | Low-dead-space needle on a Luer hub = ≈0.010 mL |
| 14 | }} | 14 | }} |
| + | 15 | {{hatnote|For the devices in which dead space is measured, see [[Insulin syringe]]. For the volume arithmetic of a reconstituted vial, see [[Reconstitution calculator]].}} | |
| 15 | 16 | ||
| 16 | '''Syringe dead space''' is the volume of liquid that remains inside a syringe and its needle after the plunger has been fully depressed. It occupies the cavity of the needle hub, the lumen of the needle itself and any recess in the face of the plunger tip, and it is not delivered to the injection site.{{r|zule2009}} | 17 | '''Syringe dead space''' is the volume of liquid that remains inside a syringe and its needle after the plunger has been fully depressed. It occupies the cavity of the needle hub, the lumen of the needle itself and any recess in the face of the plunger tip, and it is not delivered to the injection site.{{r|zule2009}} |
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| 65 | Volumes are computed as the product of cross-sectional area and length; outside diameters follow the metric equivalents of the Birmingham gauge series used in ISO 9626, and inside diameters are typical regular-wall values.{{r|iso9626}} A 27G half-inch needle therefore holds 0.44 µL, roughly one part in 160 of a 70 µL hub. Changing needle gauge or length has almost no effect on dead space; changing the hub design changes it by an order of magnitude. | 66 | Volumes are computed as the product of cross-sectional area and length; outside diameters follow the metric equivalents of the Birmingham gauge series used in ISO 9626, and inside diameters are typical regular-wall values.{{r|iso9626}} A 27G half-inch needle therefore holds 0.44 µL, roughly one part in 160 of a 70 µL hub. Changing needle gauge or length has almost no effect on dead space; changing the hub design changes it by an order of magnitude. |
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| + | 68 | {{note|Because the needle contributes so little, a device described as low dead space by virtue of having a fine needle has been described inaccurately. The relevant question is whether the plunger tip enters the hub.}} | |
| 66 | 69 | ||
| 67 | === Effect of needle length === | 70 | === Effect of needle length === |