Tetra-block: ultrasound femoral, lateral femoral-cutaneous, obturator, and sciatic nerve blocks in lower limb anesthesia: a case series

BACKGROUND

The gold standard anesthesiologic procedure for urgent femur fracture surgery is Spinal Anesthesia. It is not always feasible because of patients' severe comorbidities and difficulties in optimizing drug therapy in the appropriate time frame such as discontinuation of anticoagulant drugs. The use of four peripheral nerve blocks (tetra-block) can be a winning weapon when all seems lost.

CASE PRESENTATION

We present, in this case series, three Caucasian adult femur fractures (an 83-year-old woman, a 73-year-old man, and a 68-year-old woman) with different and major comorbidities (cardiac or circulatory disorders on anticoagulants therapy that were not discontinued on time; breast cancer and others) underwent the same anesthesiologic approach in the urgent setting. Ultrasound peripheral nerve blocks, that is femoral, lateral femoral cutaneous, obturator, and sciatic with parasacral approach were successfully performed in all patients who underwent intramedullary nailing for intertrochanteric fracture. We evaluated the adequacy of the anesthesia plane, postoperative pain control with the VAS scale, and the incidence of postoperative side effects.

CONCLUSIONS

Four peripheral nerve blocks (Tetra-block) can be alternative anesthesiologic management in urgent settings, in patients where drug therapy cannot be optimized, as in antiplatelet and anticoagulant therapy.

Comparison of three obturator nerve block techniques for injectate spread into the obturator canal: a randomized controlled trial

Purpose

The obturator nerve branches into the obturator canal; therefore, local anesthetic spread into the obturator canal predicts the success of the obturator nerve block (ONB). We compared three ONB techniques for the spread of local anesthetic mixed with contrast medium into the obturator canal.

Methods

We performed the ONB using the classical pubic approach (PA), inguinal approach (IA), or ultrasound-guided methodologic approach (UMA) in 143 patients undergoing transurethral resection of bladder tumors. The obturator nerve course and branching patterns of the UMA group were examined using ultrasound imaging. After injecting a local anesthetic mixed with a contrast medium, we evaluated its spread into the obturator canal using fluoroscopic imaging. P < 0.05 indicated statistical significance.

Results

Success rate of obturator canal enhancement was the greatest in the UMA group (84%; P < 0.001); the PA (42.6%; 20/47 patients) and IA (47.8%; 22/46 patients) groups did not differ significantly (P = 1.000). Both branches of the obturator nerve passed above the superior margin of the external obturator muscle (EOM), and the obturator canal was enhanced in 13 of 50 (26%) patients in the UMA group. The posterior branch of the obturator nerve passed between the superior and main fasciculi of the EOM in 37 of 50 patients (74%) in the UMA group; the obturator canal was enhanced in 29 of these 37 patients (78%).

Conclusion

Local anesthetic spread into the obturator canal using the UMA was superior to that using the PA and IA. Both branches of the obturator nerve could be blocked using the UMA.

Anatomic Study of the Bifurcation of the Obturator Nerve: Application to More Precise Surgical/Procedural Localization

BACKGROUND

This anatomic study aimed to more precisely locate the bifurcation of the obturator nerve in relationship to the obturator foramen. Such information might improve outcomes in neurotization or other procedures necessitating exposure of the obturator nerve and could increase success rates for obturator nerve blockade.

METHODS

Fourteen sides from fresh-frozen cadaveric specimens were used in this study. Dissection of the obturator nerve was performed, and its bifurcation into anterior and posterior branches was documented and classified. Measurements of these branches were also performed. Bifurcations of the obturator nerve were classified as type I when proximal to the obturator foramen, type II when inside the obturator foramen, and type III when distal to the obturator foramen.

RESULTS

Type I, type II, and type III obturator nerve bifurcations were observed in 14.3%, 64.3%, and 21.4% of sides, respectively. In type I nerves, the mean distance from the bifurcation of the obturator nerve to the obturator foramen was 15.8 mm, and in type II nerves the mean was 14.0 mm. The mean diameter of the main trunk, anterior branch, and posterior branch was 3.74 mm, 2.64 mm, and 2.28 mm, respectively.

CONCLUSIONS

Bifurcation of the obturator nerve can occur proximally, distally, or inside the obturator foramen. Therefore using imaging modalities such as ultrasound is strongly recommended for identifying the main trunk or anterior and posterior branches of the obturator nerve before surgery or other procedures aimed at this nerve due to such anatomic variations.

Superior perioperative analgesia with combined femoral-obturator-sciatic nerve block in comparison with posterior lumbar plexus and sciatic nerve block for ACL reconstructive surgery

PURPOSE

The purpose of this randomized controlled study is to compare and evaluate the intraoperative and post-operative outcome of PLPS nerve block and that of femoral, obturator and sciatic (FOS) nerve block as a method of anaesthesia, in performing ACL reconstruction.

METHODS

Patients referred for elective arthroscopic ACL reconstruction using hamstring autograft were divided in two groups. The first group received combined femoral-obturator-sciatic nerve block (FOS Group) under dual guidance, whereas the second group received posterior lumbar plexus block under neurostimulation and sciatic nerve block (PLPS Group) under dual guidance.

RESULTS

The two groups were comparable in terms of age, sex, BMI and athletic activity. The time needed to perform the nerve blocks was significantly shorter for the FOS group (p < 0.005). Similarly, VAS scores during tourniquet inflation and autograft harvesting were significantly higher (p < 0.005) in the PLPS group and this is also reflected in the intraoperative fentanyl consumption and conversion to general anaesthesia. Finally, patients in this group also reported higher post-operative VAS scores and consumed more morphine.

CONCLUSIONS

Peripheral nerve blockade of FOS nerve block under dual guidance for arthroscopic ACL reconstructive surgery is a safe and tempting anaesthetic choice. The success rate of this technique is higher in comparison with PLPS and results in less peri- and post-operative pain with less opioid consumption. This study provides support for the use of peripheral nerve blocks as an exclusive method for ACL reconstructive surgery in an ambulatory setting with almost no complications.

LEVEL OF EVIDENCE

I.

Classic versus Inguinal Approach for Obturator Nerve Block in Transurethral Resection of Bladder Cancer under Spinal Anesthesia: A Randomized Controlled Trial

Single spinal anesthesia in transurethral resection of bladder tumor (TURBT) has been reported to be unable to prevent obturator nerve stimulation and adductor muscle contraction, which can cause complications like bladder perforation. The present study aimed to compare the effectiveness of the classic and inguinal approaches for obturator nerve block (ONB ). Seventy patients with cancers of the lateral wall of the bladder, scheduled to undergo TURBT at Imam Reza Hospital (Tabriz, Iran) during a 6-month period as of June 2016, were randomly allocated to groups of inguinal and classic methods (n=35). After the infusion of 500 mL of normal saline, spinal anesthesia was commenced using 3 mL (15 mg) of bupivacaine. Then ONB was performed using 10 mL of 1% lidocaine via the inguinal or classic approach in the inguinal group or the classic group, respectively. The success rate, defined as lack of post-block contraction with stimulation or during surgery, number of puncture attempts, time of block onset, and patient and surgeon satisfaction, was compared between the 2 methods using SPSS, version 19. The success rate of ONB was significantly higher in the inguinal group (97.1% vs. 71.4%; P=0.003). The number of puncture attempts in the classic group was more than that in the inguinal group (3.71±1.10 vs. 1.66±0.68, respectively; P<0.001). The block onset time was shorter in the inguinal group (1.5±0.66 min vs. 2.9±1.18 min; P<0.001). Dissatisfaction of the patient (19 cases vs. 2 cases) and the surgeon (10 cases vs. no case) was higher in the classic group (P<0.001). Compared to the classic approach, the inguinal approach for ONB appeared to be an easily performable, effective block with a high success rate, rapid onset, and good patient and surgeon satisfaction.

TRIAL REGISTRATION NUMBER

IRCT 201608171772N21.

Obturator Nerve Block in Transurethral Resection of Bladder Tumor: A Comparative Study by two Techniques

CONTEXT

Sparing of obturator nerve is a common problem encountered during transurethral resection of bladder tumor (TURBT) under spinal anesthesia.

AIMS

To evaluate and compare obturator nerve block (ONB) by two different techniques during TURBT.

SETTINGS AND DESIGN

This is prospective observational study.

SUBJECTS AND METHODS

Forty adult male patients from the American Society of Anesthesiologists Class I-IV planned to undergo TURBT under spinal anesthesia were divided into two groups of twenty each. In one group, ONB was performed with nerve locator. In other group, transvesical nerve block was performed with a cystoscope. The primary endpoints of this study were the occurrence of adductor reflex, ability to resect the tumor, and number of surgical interruptions. A number of transfusions required and bladder perforation were the secondary endpoints.

RESULTS

There was statistically significant difference between the groups for resection without adductor jerk, resection with a minimal jerk, and unresectable with high-intensity adductor jerk. Bleeding was observed in both groups and one bladder perforation was encountered.

CONCLUSIONS

We conclude that ONB, when administered along with spinal anesthesia for TURBT, is extremely safe and effective method of anesthesia to overcome adductor contraction. ONB with nerve locator appears to be more effective method compared to the transvesical nerve block.

Comparison of the success rate of inguinal approach with classical pubic approach for obturator nerve block in patients undergoing TURB

Background

During transurethral resection of bladder tumors (TURB) under spinal anesthesia, electrical resection of the lateral wall mass may cause violent adductor contraction and possible inadvertent bladder perforation. Therefore, obturator nerve block (ONB) is mandatory after spinal anesthesia to avoid adductor muscle contraction. We compared the success rate and efficacy of an inguinal approach, to a pubic approach for ONB.

Methods

One hundred and two patients who required ONB undergoing TURB with spinal anesthesia were included in this study. After spinal anesthesia, ONB was performed with an inguinal approach (Group I, n = 51) or pubic approach (Group P, n = 51) using a nerve stimulator. In the pubic approach, a needle was inserted at a point 1.5 cm lateral and 1.5 cm inferior to the pubic tubercle. For the inguinal approach, a needle was inserted at the midpoint of the femoral artery and the inner margin of the adductor longus muscle 0.5 cm below the inguinal crease. If the adductor contracture had not occurred by the 3rd attempt, it was defined as a failed block. Puncture frequency, success rate, anatomical characteristics, and the presence of adductor muscle contraction during operation were evaluated.

Results

The success rate of ONB was higher in group I compared to group P (96.1% vs. 84.0%, P = 0.046) and the frequency of needle attempts was lower in group I than in group P (1.8 ± 0.9 vs. 1.3 ± 0.6, P = 0.01).

Conclusions

The inguinal approach for ONB appears to be technically easier and offers certain anatomical advantages when compared to the pubic approach.

Efficacy of ultrasound-guided obturator nerve block in transurethral surgery

Background:

During transurethral resection surgery (TUR), accidental stimulation of the obturator nerve can cause violent adductor contraction, leading to serious intraoperative complications. General anesthesia with muscle relaxation is currently the preferred technique for TUR surgery. Spinal anesthesia combined with obturator nerve block has also been used for TUR surgery in geriatric population. Blind, anatomical methods for identifying the obturator nerve are often unsatisfactory. Therefore, we conducted this prospective study to validate the efficacy of ultrasound-guided obturator nerve block (USONB) during TUR procedures.

Methods:

Eighteen male patients undergoing TURP surgery under spinal anesthesia were included in the study. Bilateral USONB with maximum 20 ml of 1% lidocaine per patient was performed. An independent observer was present to monitor any adduction movements during the operation and to record patient and surgeon satisfactions.

Results:

In all patients, obturator nerve was visualized from the first attempt, requiring an average of 4.3 min for blocking of each side. USONB was successful (97.2%) in preventing an adductor spasm in all except one patient. Patient’s and surgeon’s satisfaction were appropriate. In all patients, adductor muscle strength recovered fully within 2 h following the surgical procedure.

Conclusions:

USONB is safe and effective during TUR surgery. It provides optimal intra-and postoperative conditions.