Flow characteristics of long spinal needles

PDPH is a common complication of neuraxial blockade in parturients: a meta-analysis of obstetrical studies

PURPOSE

Postdural puncture headache (PDPH) is an iatrogenic complication of neuraxial blockade. We systematically reviewed the literature on parturients to determine the frequency, onset, and duration of PDPH.

METHODS

Citations on PDPH in the obstetrical population were identified by computerized searches, citation review, and hand searches of abstracts and conference proceedings. Citations were included if they contained extractable data on frequency, onset, or duration of PDPH. Using meta-analysis, we calculated pooled estimates of the frequency of accidental dural puncture for epidural needles and pooled estimates of the frequencies of PDPH for epidural and spinal needles.

RESULTS

Parturients have approximately a 1.5% [95% confidence interval (CI) 1.5% to 1.5%) risk of accidental dural puncture with epidural insertion. Of these, approximately half (52.1%; 95% CI, 51.4% to 52.8%) will result in PDPH. The risk of PDPH from spinal needles diminishes with small diameter, atraumatic needles, but is still appreciable (Whitacre 27-gauge needle 1.7%; 95% CI, 1.6% to 1.8%). PDPH occurs as early as one day and as late as seven days after dural puncture and lasts 12 hr to seven days.

CONCLUSION

PDPH is a common complication for parturients undergoing neuraxial blockade.

Spinal anaesthesia--the current trend towards narrow gauge atraumatic (pencil point) needles. Case reports and review

Advances in manufacturing technology have led to the wider availability and affordability of narrow gauge atraumatic spinal needles. The use of these needles is the most effective method available for anaesthetists to reduce the incidence of post dural puncture headache. Their use in all circumstances however, may not be appropriate in light of the problems which may be associated. These problems are illustrated here by four case reports and a review of the literature.

Prospective clinical evaluation of two combined spinal-epidural kits

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 the 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.