A hazard of double-orifice epidural catheters

Acute cauda equina syndrome after total knee arthroplasty as a result of epidural anesthesia and spinal stenosis

An unusual complication of epidural anesthesia performed for routine total knee arthroplasty is presented. Epidural catheter placement or removal resulted in an acute cauda equina syndrome in a patient with asymptomatic high-grade lumbar spinal stenosis at L3-4. The case is presented along with a literature review.

Uniport soft-tip, open-ended catheters versus multiport firm-tipped close-ended catheters for epidural labor analgesia: a quality assurance study

STUDY OBJECTIVE

To compare a multiport, firm-tipped, close-ended, epidural catheter (Portex catheter) with a uniport, open-ended, soft-tipped, wire-reinforced catheter (Arrow catheter) in obstetric patients.

STUDY DESIGN

Prospective data collection for intradepartmental quality assurance.

SETTING

Obstetric unit in a tertiary care maternity hospital.

PATIENTS

2612 patients requesting labor analgesia.

INTERVENTIONS

The Arrow catheter was used in 1,352 women and the Portex catheter in 1,260 women.

MEASUREMENTS AND MAIN RESULTS

The incidence of unsatisfactory block were 3.3% and 4.4% with the Arrow and Portex catheters, respectively (p = 0.2). The catheter perforated the dura matter in 0.4% of cases with both catheters. The incidence of epidural venipuncture was 1.1% with the Arrow catheter and 5.7% with the Portex catheter (p = 0.0001). Paresthesias occurred in 6% of cases with the Arrow catheter and 11. 2 % of cases with the Portex catheter (p = 0.0001). Epidural catheter reinsertion was required in fewer patients in the Arrow group than in the Portex group (4.8% vs. 7.1%; p = 0.01).

CONCLUSIONS

In obstetric patients, the softer uniport Arrow catheter produces paresthesias and venipunctures less frequently than the firm multiport Portex catheter.

The intravascular migration of an epidural catheter

The intravascular migration of an endhole epidural catheter in a child is described. We suggest measures to reduce the risk of inadvertent intravenous administration of local anaesthetic and means of reducing the effects of this with particular relevance to paediatric practice.

A comparison of multiport and uniport epidural catheters in laboring patients

The relative incidence of technical difficulties associated with multiport (three lateral ports) and uniport (single distal port) epidural catheters remains controversial. As part of a continuing institutional evaluation of epidural catheter insertion, 500 parturients were randomized to have either a multiport or a uniport epidural catheter inserted 6 cm into the epidural space. Multiport epidural catheters were associated with inadequate analgesia less often and required manipulation less often than uniport epidural catheters. The incidences of intravenous cannulation, subsequent catheter dislodgement, and catheter replacement were similar for each catheter type. No multiport epidural catheter was associated with multicompartment placement. We conclude that multiport epidural catheters are preferable for use in laboring patients since they reduce the incidence of inadequate epidural analgesia.

Superiority of multi-orifice over single-orifice epidural catheters for labor analgesia and cesarean delivery

STUDY OBJECTIVE

To investigate whether a change from a single-orifice to multi-orifice catheter could reduce the incidence of inadequate epidural blocks requiring replacement of the epidural catheter in obstetric patients.

STUDY DESIGN

Prospective before-after cohort study.

SETTING

Obstetric unit at a university hospital.

PATIENTS

872 patients requesting epidural analgesia for vaginal delivery or cesarean section.

INTERVENTIONS

Patients received epidural analgesia via single-orifice (n = 433) or multi-orifice (n = 439) epidural catheters, depending on the month of the trial.

MEASUREMENTS AND MAIN RESULTS

Patient characteristics, obstetric procedure, anesthesiologist characteristics, and details of epidural placement did not differ significantly between the groups. The overall replacement rate was 14.3% in the single-orifice group versus 9.3% in the multi-orifice group (p = 0.032). There were no difference in the frequency of replacement for subarachnoid placement or migration, immediate intravascular placement, vascular migration, or absence of any block. Significantly fewer catheters were replaced in the multi-orifice group for inadequate analgesia, defined as unblocked segments or unilateral block (6.4% vs. 2.8%, p = 0.018). Paresthesias were less common in the multi-orifice group (22.4% vs. 31.5%, p = 0.003). There were no unrecognized subarachnoid or vascular catheter placements in either group.

CONCLUSIONS

The multi-orifice design offers significant advantages over the single-orifice type for obstetricepidural analgesia.

Misplacement of multihole epidural catheters--a report of two cases

The misplacement of a multihole (three lateral holes) epidural catheter such that it lies partly in the subdural space is demonstrated in two patients by means of epidurographic studies.

A new epidural catheter. Closer eyes for safety?

A new design of epidural catheter with three lateral eyes placed in close proximity to its closed end is described. Prototype models of this catheter were tested in 200 obstetric and surgical patients. In a single-blind randomised study it was found to be easy to insert and highly satisfactory in use, when compared to the current catheter type, with three widely spaced lateral eyes. It is hoped that the close spacing of the eyes will eliminate the complication of multicompartment block, as seen with earlier multihole catheters, and improve the safety of epidural block.

Differential flow from multihole epidural catheters

The pressures used in vivo to administer epidural doses of local anaesthetic were recorded for 16- and 18-gauge multihole catheters. Observations were made on 10 patients in labour for each catheter gauge. The pressure range for the 16-gauge catheters was 39.9-266 kPa, with a mean of 167.2 kPa, and for 18-gauge, a range of 53.2-266 kPa, mean, 159 kPa. Similar pressures were then applied in vitro to 10 catheters of each gauge, and the flow of fluid observed from the three holes. For each size of catheter, with increasing pressure, flow appeared at the proximal, then the middle, and finally the distal hole. This emphasises that the effect of epidural doses can vary depending on the pressure of injection, especially if the catheter had been passed partially through the dura.

Unintentional dural puncture. A survey of recognition and management

A survey of the recognition and management of 21 unintentional dural punctures that occurred in a series of 3500 obstetric epidurals is presented. In seven cases, dural puncture was not recognised at the time of occurrence and two patients may have subsequently received mixed epidural and subarachnoid analgesia. In two patients with dural puncture in whom air had been used to locate the epidural space, cerebrospinal fluid did not drip from the hub of the needle. A test dose did not reveal incorrect catheter placement in seven patients. The provision of an epidural infusion of Hartmann's solution for 24 hours, together with bed rest, appeared to delay the onset of dural puncture headache rather than prevent it entirely. Blood patching was required only in five of the 21 patients but was entirely successful. The implications of these observations in relationship to obstetric epidural practice are discussed.

Epidural catheters of the multi-orifice type: dangers and complications

A study on epidural catheters of the multi-orifice type, investigating their tendency to epidurovasal (with an intravascularly positioned catheter tip) and epidurosubarachnoid (with the catheter tip inserted in the subarachnoid space) malpositioning, was conducted on 113 patients using clinical and radiological criteria as controls. Of the improperly placed catheters, 13 were in an epidurovasal (11.5%) and one was in an epidurosubarachnoid (0.9%) position. The findings demonstrate the occasional hazardous dual compartmental misplacement of multi-orifice catheters, in which a distal opening can lie intravascularly or within the subarachnoid space, while a proximal orifice simultaneously retains normal access to the epidural space. The insufficiency of controlling or even recognizing such improperly placed catheters which are only partially in the epidural space, as well as the danger of causing a secondary dural or vascular perforation with epidural catheters, is discussed. Since epidural catheters of the multi-orifice type apparently represent an inherent, vital danger due to their construction (regardless of the catheter material and workmanship), they should no longer be used.