Background and objective: Although combined spinal and epidural anaesthesia is efficient and easy to perform, the technique can be a double-edged sword having the potential risk that an increased flux of drugs across the meninges through the hole made in it may lead to severe adverse effects. The aim was to compare the incidence of adverse events when an epidural injection of morphine was given after combined spinal and epidural anaesthesia or after epidural anaesthesia.

Methods: Fifteen patients had an epidural catheter inserted at the L2–3 interspace, and then a spinal block administered via the L3–4 interspace. Another 15 patients only had an epidural catheter inserted. After the onset of spinal or epidural anaesthesia had been confirmed, morphine 2 mg was injected into the epidural space, and a continuous epidural infusion of morphine was started. At the end of the operation and at 4, 8 and 12 h after the administration of epidural morphine and on the next day, the following variables were examined: blood pressure, heart rate, respiratory rate, arterial blood-gas analysis, visual analogue scale pain scores, nausea/ vomiting scores, and pruritus scores.

Results: In the study population, the epidural injection of morphine was not associated with a significantly higher incidence of adverse events when given after spinal anaesthesia than after epidural anaesthesia.

Conclusions: The adverse effects associated with epidural morphine given after spinal anaesthesia did not increase significantly when a 27-G Whitacre needle was used. Thus, the morphine flux through the meningeal hole into the cerebrospinal fluid was trivial.

Background and objective In recent studies, ultrasonic diagnostic imaging has proved useful in the screening of the trajectory of the epidural needle. With regard to possible side-effects of spinal and epidural anaesthesia caused by vessel injury, we aimed to evaluate the usability of Colour Doppler imaging for the depiction of interspinous vessels in prepuncture examination.

Methods Ultrasonic examination of the L¾ interspace area was performed in 20 volunteers. Using a 4-MHz and a 7-MHz probe with B-mode and Colour Doppler imaging, respectively, we compared four settings for the quality of vessel depiction in the puncture area. Overall resolution was evaluated according to the distinction of landmarks. Vascular structures were identified by pulsation (B-mode) or blood flow (Doppler).

Results Colour Doppler imaging of the L3/4 interspace was unachievable using the 7-MHz transducer. Vessel detection was possible in 50% of the B-mode images and in all of the 4-MHz Doppler images. Vessels were perceptible from a diameter of 0.5 mm. Veins were the predominantly visible structures. Overall vessel visibility was best using 4-MHz Colour Doppler.

Conclusions Prepuncture Doppler imaging can provide the epiduralist with information regarding the position of vessels in the needle trajectory. This might help to reduce complications in regional anaesthesia.