Combined femoral and sciatic nerve blocks sufficient to control tourniquet-induced hypertension in Lower-Limb Surgery: Study

Tourniquet-induced hypertension (TH) is still a challenging problem, and different strategies like peripheral nerve blocks, peri-femoral artery blocks, and subcutaneous infiltration have been investigated to manage it. Recent study aimed to compare the efficacy of peri-femoral artery block (P-FAB) and subcutaneous infiltration, both combined with femoral and sciatic nerve blocks, in reducing tourniquet-induced hypertension (TH) during lower-limb surgery under general anesthesia. The primary objective was to compare the incidence of TH between the two groups. Secondary objectives included intraoperative use of intravenous fentanyl and antihypertensive medications, as well as postoperative pain scores.

The study was a single-center, double-blind, randomized controlled trial involving 58 patients scheduled for elective lower-limb surgery. Participants were randomly assigned to the P-FAB or subcutaneous infiltration (SI) groups. All patients received general anesthesia with femoral and sciatic nerve blocks. TH was defined as a 30% increase in systolic blood pressure from baseline. The results showed no significant difference in the incidence of TH between the P-FAB and SI groups (51.9% vs 51.9%, p=1.00). Similarly, there were no significant differences in intraoperative fentanyl (p=0.459) or antihypertensive use (p=0.992). Pain scores at the thigh and surgical sites, measured using a numerical rating scale, were also not significantly different between the two groups (p>0.05).

Conclusion

In conclusion, adding a peri-femoral artery block to general anesthesia with femoral and sciatic nerve blocks did not reduce the incidence of tourniquet-induced hypertension compared to subcutaneous infiltration in patients undergoing lower-limb surgery. The findings suggest that the use of combined femoral and sciatic nerve blocks may be sufficient to mitigate the effects of tourniquet-induced hypertension, and the addition of a peri-femoral artery block does not provide further benefits.

Key Points

1. The study aimed to compare the efficacy of peri-femoral artery block (P-FAB) and subcutaneous infiltration, both combined with femoral and sciatic nerve blocks, in reducing tourniquet-induced hypertension (TH) during lower-limb surgery under general anesthesia.

2. The primary objective was to compare the incidence of TH between the P-FAB and subcutaneous infiltration (SI) groups. Secondary objectives included intraoperative use of intravenous fentanyl and antihypertensive medications, as well as postoperative pain scores.

3. The study was a single-center, double-blind, randomized controlled trial involving 58 patients scheduled for elective lower-limb surgery. Participants were randomly assigned to the P-FAB or SI groups.

4. The results showed no significant difference in the incidence of TH between the P-FAB and SI groups (51.9% vs 51.9%, p=1.00). There were also no significant differences in intraoperative fentanyl use or antihypertensive use.

5. Pain scores at the thigh and surgical sites, measured using a numerical rating scale, were not significantly different between the two groups (p>0.05).

6. The findings suggest that the use of combined femoral and sciatic nerve blocks may be sufficient to mitigate the effects of tourniquet-induced hypertension, and the addition of a peri-femoral artery block does not provide further benefits.

Reference –

Chonruethai Tangkittithaworn et al. (2024). Efficacy Of Local Anaesthetic Peri-Femoral Artery Injection Compared To Subcutaneous Infiltration In Combination With Femoral And Sciatic Nerve Blocks For Reducing Thigh Tourniquet-Induced Hypertension During Lower-Limb Surgery Under General Anaesthesia: A Randomised Controlled Double-Blinded Trial. *Indian Journal Of Anaesthesia*. https://doi.org/10.4103/ija.ija_968_24.