From the Guidelines
An ESP block typically spreads 3-5 spinal levels from the injection site. The spread of an ESP block can vary based on several factors, including the volume of local anesthetic injected, patient positioning, anatomy, age, and the specific technique used by the anesthesiologist 1. The volume of local anesthetic injected is the primary determinant of spread, with larger volumes covering more segments. Patient positioning during and after injection affects spread through gravity, with local anesthetic flowing to dependent areas. Other factors influencing spread include the patient's anatomy, age (elderly patients often experience greater spread due to narrowed epidural spaces), and the concentration and type of local anesthetic used.
Some studies have shown that the spread of an ESP block can be influenced by the surgical approach, with open procedures requiring a higher level of block than laparoscopic procedures 1. For example, in open rectal surgery, a thoracic epidural anesthesia (TEA) inserted at the T10 level may not be sufficient to cover the perineal and sacral incisions, and additional measures such as adding morphine to bupivacaine or inserting another epidural at the lumbar level may be necessary.
In terms of morbidity, mortality, and quality of life, the goal of an ESP block is to provide adequate pain relief while minimizing unwanted effects on other body systems. Anesthesiologists carefully titrate the dose and monitor the block's extent to achieve this goal. The use of multimodal analgesia, including paracetamol, non-steroidal anti-inflammatory drugs (NSAIDs), and cyclo-oxygenase (Cox)-2 inhibitors, can also help to spare opioid use and side effects 1.
Key factors that influence the spread of an ESP block include:
- Volume of local anesthetic injected
- Patient positioning during and after injection
- Anatomy
- Age
- Concentration and type of local anesthetic used
- Surgical approach (open vs laparoscopic) It is essential to consider these factors when administering an ESP block to ensure adequate pain relief and minimize unwanted effects.
From the Research
ESP Block Spread Levels
- The studies provided do not directly address the question of how many levels an ESP block spreads 2, 3, 4, 5, 6.
- However, some studies mention the sensory block levels achieved with different combinations of local anesthetics and adjuvants:
- In one study, the median maximum sensory block level achieved after spinal component was T6, and the median highest sensory block level achieved after epidural anesthetic bolus was T7-4seg enhancement after regression to T11 2.
- Another study found that the highest dermatome level of sensory block was not significantly different between groups receiving different combinations of bupivacaine, fentanyl, and clonidine 3.
- It is worth noting that the spread of an ESP block can depend on various factors, including the type and dose of local anesthetic used, the addition of adjuvants, and individual patient characteristics.
- Further research would be needed to provide a more specific answer to the question of how many levels an ESP block spreads.