Studies on the spread of local anaesthetic solution in transversus abdominis plane blocks*

Abstract

SummaryThe extent of analgesia provided by transversus abdominis plane blocks depends upon the site of injection and pattern of spread within the plane. There are currently a number of ultrasoundguided approaches in use, including an anterior oblique-subcostal approach, a mid-axillary approach and a more recently proposed posterior approach. We wished to determine whether the site of injection of local anaesthetic into the transversus abdominis plane affects the spread of the local anaesthetic within that plane, by studying the spread of a local anaesthetic and contrast solution in four groups of volunteers. The first group underwent the classical landmark-based transversus abdominis plane block whereby two different volumes of injectate were studied: 0.3 ml.kg )1 vs 0.6 ml.kg )1 . The second group underwent transversus abdominis plane block using the anterior subcostal approach. The third group underwent transversus abdominis plane block using the mid-axillary approach. The fourth group underwent transversus abdominis plane block using the posterior approach, in which local anaesthetic was deposited close to the antero-lateral border of the quadratus lumborum. All volunteers subsequently underwent magnetic resonance imaging at 1, 2 and 4 h following each block to determine the spread of local anaesthetic over time. The studies demonstrated that the anterior subcostal and mid-axillary ultrasound approaches resulted in a predominantly anterior spread of the contrast solution within the transversus abdominis plane and relatively little posterior spread. There was no spread to the paravertebral space with the anterior subcostal approach. The mid-axillary transversus abdominis plane block gave faint contrast enhancement in the paravertebral space at T12-L2. In contrast, the posterior approaches, using both landmark and ultrasound identifications, resulted in predominantly posterior spread of contrast around the quadratus lumborum to the paravertebral space from T5 to L1 vertebral levels. We concluded that the pattern of spread of local anaesthetic differs depending on the site of injection into the transversus abdominis plane. This may have important implications for the extent of analgesia produced with each approach.

Evaluation of the effectiveness of the Quadratus Lumborum Block type I using ropivacaine in postoperative analgesia after a cesarean section — a controlled clinical study

“…Carney et al demonstrated, by using an MRI of the chest and abdomen, when comparing between four groups of volunteers, that the spread of LA after TAPB occurs only in the area of the transversus abdominis plane, determining a slowdown of only somatic pain and providing a sensory block only within the scope of the innervation of Th9-Th10 or Th11-L1. Conversely, the block within the QLM revealed the spread of the contrast towards the paravertebral space between Th4-L1 spaces [10,13,23]. The aim of our study was to confirm what Blanco indicated in 2007, that a new concept of the block of the abdominal wall of the inhibitory effect of somatic and visceral pain, the so called paravertebral block component, was beneficial [14,15].…”

“…Dozens of clinical trials and their meta-analyses show that TAPB, as a component of multimodal pain therapy, provides effective analgesia after a C-section within the field of somatic pain which in fact is only coming from the abdominal wall [10][11][12]. Conducting research on a new access to TAPB using ultrasound led to the Quadratus Lumborum Block (QLB) [13,14]. A unique component of the QLB is not only that it stops somatic pain but also that it inhibits visceral pain due to the spread of the local anesthetic to the paravertebral space.…”

Abdominal Surgery: Advances in the Use of Ultrasound-Guided Truncal Blocks for Perioperative Pain Management

“…Actually, the block has never been intended to be conducted without the use of US guidance, and the block is thus a purely USG block. In an absolutely brilliant paper by Carney et al the block is compared to other TAP block techniques using volunteers rather than patients (Carney 2011). Dr. Carney found that there was a non-contiguous paravertebral, epidural and lymphatic contrast enhancement Th5-Th10 in one subject, and similarly contrast at Th6-Th10 in two other subjects (Carney 2011).…”

“…The IHN provides sensation to the buttock and abdominal wall above the pubis (Abrahams 2010). In our own previous studies, we have been unable to register effective dermatomal anaesthesia of the L1 branch with our BD-TAP block technique, but other studies have shown the L1 branches to be blocked by other versions of the TAP block technique , Carney 2011. For the selective USG IIN/IHN block the patient is placed in a supine position, and the anterior superior iliac spine (ASIS) is localized by palpation first and since ultrasonographically (Fig.…”

“…If post-or perioperative pain sensations are predominantly transmitted via the autonomic nervous system, then the choice of analgesic management would today primarily rely on continuous intrathecal and especially epidural infusions of local anaesthetic. It is also possible to block central visceral pain conduction with thoracic paravertebral blockade or maybe even with the novel quadratus lumborum block (Carney 2011). We will deal with these blocks later in this chapter.…”