One hundred combined spinal-epidural kits (Portex, n = 51, Mallinckrodt, n=49) were evaluated clinically by twelve anaesthetists with respect to performance of the loss-of-resistance syringe, epidural needle and spinal needle, and success in establishing single-segment combined spinal-epidural anaesthesia for caesarean section. Similar components included a plastic loss-of-resistance device, a Tuohy epidural needle, 26 or 27 gauge pencil-point spinal needle and closed end, three-lateral-eye epidural catheter. The Mallinckrodt kit incorporated a “back-eye” design for exit of the spinal needle from the epidural needle. The epidural and subarachnoid spaces were satisfactorily identified on 98 occasions. Most anaesthetists preferred the Mallinckrodt kit packaging and the Portex loss-of-resistance syringe, although the latter may have been biased by familiarity with this device. The Portex spinal needle was more likely to be felt penetrating the dura (P=0.02) and aspiration of cerebrospinal fluid was more frequently described as easy (P=0.01). The most common criticisms of both kits were difficulty controlling the spinal needle position after entry into the subarachnoid space and subjectively, a high degree of resistance to injection through the spinal needle.
Loss of Resistance to Saline Reduces Responses Accompanying Spinal Needle Insertion during Institution of ‘Needle-Through-Needle’ Combined Spinal-Epidural Analgesia
