From the Guidelines
Tap blocks typically last for approximately 6 hours, as evidenced by the study of Elkassabany et al. 1, which found that VAS scores were lower during only 6 hours in the TAP block group. The duration of tap blocks can vary depending on several factors, including the type and dose of local anesthetic used, as well as individual patient factors such as metabolism and body composition.
- The study of Elkassabany et al. 1 used 20 ml of 5-mg/ml bupivacaine for the TAP block, which may have contributed to the relatively short duration of action.
- Other studies, such as those by Skjelsager et al. 1 and Maquoi et al. 1, did not find a significant difference in pain scores or morphine consumption between the TAP block group and the control group, which may suggest that the duration of the block was not sufficient to provide significant pain relief.
- However, the study of Dal Moro et al. 1 found that a bilateral TAP block performed postoperatively with 200 ml of 2.5 mg/ml bupivacaine resulted in lower pain scores and postoperative analgesic requirements, which may suggest that a higher volume or dose of local anesthetic can provide longer-lasting pain relief.
- It is also worth noting that the use of additives such as epinephrine or dexamethasone can extend the duration of the block, but this was not investigated in the studies mentioned above.
- For optimal pain management, patients should be advised to take their prescribed oral pain medications before the block completely wears off to prevent breakthrough pain.
- The block's duration is limited by the pharmacokinetics of the local anesthetic, which gradually gets absorbed into the bloodstream from the fascial plane where it was injected.
- Some surgeons and anesthesiologists may place catheters for continuous infusion in cases where longer pain control is needed, which can extend the analgesic effect for several days.
- Understanding the expected duration helps patients and healthcare providers plan appropriate supplemental pain management strategies.
From the Research
Duration of Tap Blocks
- The duration of tap blocks can vary depending on the type of local anesthetic used 2, 3, 4, 5, 6.
- Studies have shown that bupivacaine can provide a longer duration of anesthesia compared to lidocaine, with a duration of action ranging from 14.1 to 21.5 hours 2, 3, 4, 6.
- Ropivacaine has also been shown to provide a long duration of anesthesia, with a duration of action ranging from 13.8 to 15.8 hours 3, 4.
- The addition of epinephrine to local anesthetics can also affect the duration of anesthesia, with some studies showing a longer duration of action with epinephrine 2, 3.
- The timing of administration of tap blocks can also impact the duration of anesthesia, with some studies showing no significant difference in postoperative pain scores or opioid consumption when blocks are administered before or after induction of anesthesia 5.
Factors Affecting Duration of Tap Blocks
- The type and concentration of local anesthetic used can affect the duration of anesthesia 2, 3, 4, 6.
- The addition of epinephrine to local anesthetics can also affect the duration of anesthesia 2, 3.
- The timing of administration of tap blocks can also impact the duration of anesthesia 5.
- Patient factors, such as age and medical history, can also affect the duration of anesthesia 6.
Comparison of Local Anesthetics
- Bupivacaine and ropivacaine are commonly used long-acting local anesthetics for peripheral nerve blocks 2, 3, 4.
- Lidocaine is a shorter-acting local anesthetic that can provide a faster onset of anesthesia, but a shorter duration of action 2, 3, 6.
- The choice of local anesthetic depends on the specific procedure and patient needs, as well as the desired duration of anesthesia 3, 4, 6.