Plasma concentrations of bupivacaine following combined sciatic and femoral 3 in 1 nerve blocks in open knee surgery

Adding a low-concentration sciatic nerve block to total knee arthroplasty in patients susceptible to the adverse effects of non-steroidal anti-inflammatory drugs (NSAIDs): a randomized controlled trial

Background

This study compared the effects of adductor canal blocks with those of a low concentration of popliteal-sciatic nerve block (SNB) and dexamethasone as an adjunctive technique for total knee arthroplasties (TKA) in patients susceptible to the adverse effects of NSAIDs.

Methods

A prospective, double-blinded, randomized controlled trial was performed in 50 patients susceptible to the adverse effects of NSAIDs undergoing unilateral TKAs. All patients received spinal anesthesia, adductor canal blocks, and periarticular infiltration. The 25 patients in the intervention group received SNB (0.125% bupivacaine [20 ml] and dexamethasone [5 mg]).

Results

The SNB group significantly had lower median resting pain scores at 6, 12, and 18 h: the control group, 1 (0–4.5), 3 (0–5), and 3 (2–5); the intervention group, 0 (0–0), 0 (0–3), and 1 (0–3); p-values, 0.012, 0.021, and 0.010, respectively. Movement-evoked pain scores at 6, 12, and 18 h were also lower: control group, 3 (0–5.5), 5 (2.5–6.5), and 7 (4–9); intervention group, 0 (0–1.5), 2 (0–4), and 3 (2–5); p-values, 0.019, 0.005, and 0.001, respectively. There were no differences in motor function. Moreover, the mean morphine consumption 24 h was also reduced in the SNB group: control group, 3.80 ± 2.48 mg; intervention group, 1.96 ± 2 mg; p-value, 0.005.

Conclusion

For patients susceptible to the adverse effects of NSAIDs, a low concentration of SNB and dexamethasone is an effective adjunctive technique for early postoperative pain control (especially on movement) following TKAs, without an increase in motor weakness.

Trial registration

ClinicalTrials.gov, NCT03486548, Registered 3 April 2018.

Regional anaesthesia in trauma

Regional anaesthesia is very effective in alleviating pain due to trauma, and is also used to provide anaesthesia for trauma surgery. It has the advantage of producing localized but complete pain relief, whilst avoiding the side effects of systemic analgesics or anaesthetics. However, regional anaesthetic drugs and techniques have potentially life-threatening complications, which the practitioner must be able to manage. This article discusses the use of regional anaesthesia, and the benefits and disadvantages of specific regional techniques in various traumatic conditions.

Optimizing dose infusion of 0.125% bupivacaine for continuous femoral nerve block after total knee replacement

Background

The optimal dose infusion of 0.125% bupivacaine via a femoral catheter after total knee replacement (TKR) has not been defined. This study examined various dose infusions of bupivacaine to determine the analgesic quality in patients receiving a continuous femoral nerve block (CFNB).

Methods

Patients were randomized to receive a single-injection femoral nerve block (SFNB) or CFNB performed with 20 ml of 0.125% bupivacaine, followed by a continuous infusion of 0.125% bupivacaine in four groups (n = 20 per group): 1) 0 ml/h (SFNB), 2) 2 ml/h, 3) 4 ml/h, and 4) 6 ml/h. The pain intensity at rest and on knee movement was assessed using a visual analog scale (VAS) for the first 2 postoperative days. The cumulative bolus use of IV patientcontrolled analgesia (PCA) with a morphine-ketorolac combination was evaluated.

Results

A lower cumulative bolus of IV PCA was noted in all CFNB groups compared to SFNB on postoperative days (PODs) 1 and 2, respectively (P < 0.05). Lower VAS scores at rest were observed in the 4 ml/h and 6 ml/h groups than in the SFNB group on PODs 1 and 2, respectively, but only on POD 2 in the 2 ml/h group (P < 0.05). Lower VAS scores on movement were noted in the 4 ml/h than the SFNB group on PODs 1 and 2, but only on POD 1 in 6 ml/h (P < 0.05).

Conclusions

The minimum effective infusion rate of 0.125% bupivacaine for CFNB after TKR appears to be 4 ml/h according to the VAS pain scores.

[Efficacy of obturator and femoral cutaneous nerve blocks for postoperative analgesia in hip surgery]

OBJECTIVES

The treatment of pain after surgery to repair a hip fracture is essential for an early start of rehabilitation and for reducing morbidity and mortality. Given that patients are elderly and have multiple medical conditions, local-regional analgesia can be an effective approach. Our aim was to compare the efficacy of obturator and femoral cutaneous nerve blocks and total intravenous analgesia in terms of level of patient satisfaction, complications, start of rehabilitation, and cost.

PATIENTS AND METHODS

Prospective study of 75 patients undergoing surgery to repair hip fractures. Patients were randomized to receive intravenous analgesia only, blockade of both nerves, or blockade of only the obturator nerve. In each group we recorded visual analog scale (VAS) pain scores, satisfaction with postoperative analgesia, time elapsed until start of rehabilitation, need for postoperative analgesics, side effects, and the cost of drugs.

RESULTS

Analgesia was significantly more effective in patients with nerve blocks than in those who received only intravenous analgesia (mean [SD] VAS scores, 2.6 [1.4] and 5.6 [0.7], respectively). Patients with nerve blocks also had a pain-free period of more than 24 hours (P < .001), needed fewer doses of supplementary analgesics or other drugs, had fewer side effects (P < .01), started rehabilitation earlier (32.6 [5.4] hours vs 45.7 [8.2] hours), generated less expenditure (2.6 Euros [1.5 Euros]/patient vs 7.0 Euros [0.4 Euros]/patient). The tested techniques had no complications.

CONCLUSIONS

The nerve blocks were effective, easy to perform, and safe. They afforded numerous advantages: extended period of postoperative analgesia, fast recovery, lower costs, and no complications.

Bloqueio do plexo lombar no compartimento do psoas para analgesia pós-operatória em cirurgias ortopédicas

OBJETIVOS: O plexo lombar foi localizado entre os músculos quadrado lombar e psoas maior. O objetivo deste estudo foi avaliar a eficácia da injeção única de bupivacaína 0,25% através do bloqueio do compartimento do psoas na analgesia pós-operatória em pacientes de cirurgias ortopédicas. MÉTODO: Quarenta pacientes receberam bloqueio do plexo lombar no compartimento do psoas através da localização com estimulador de nervos e injeção de bupivacaína a 0,25%. Avaliou-se a analgesia e a intensidade da dor às 4, 8, 12, 16, 20 e 24 horas após o término da cirurgia, assim como opióides de resgate. RESULTADOS: Os nervos ilioinguinal, genitofemoral, cutâneo femoral lateral, femoral e obturatório foram bloqueados em 90% dos pacientes. O bloqueio reduziu o regaste de opióides administrados, sendo que 52,5% dos pacientes não necessitaram de complementação analgésica, com duração de 24 horas. Não foram observados sinais e sintomas clínicos da toxicidade da bupivacaína, nem seqüelas associadas com o bloqueio dos nervos. CONCLUSÕES: Este estudo mostra que a injeção no espaço do compartimento do psoas é fácil de realizar com efetivo bloqueio dos cinco nervos. O bloqueio do plexo lombar no compartimento do psoas pode ser recomendado para o uso na analgesia pós-operatória após cirurgias ortopédicas.

Double-blind comparison of ropivacaine 7.5 mg ml(-1) with bupivacaine 5 mg ml(-1) for sciatic nerve block

Two groups of 12 patients had a sciatic nerve block performed with 20 ml of either ropivacaine 7.5 mg ml(-1) or bupivacaine 5 mg ml(-1). There was no statistically significant difference in the mean time to onset of complete anaesthesia of the foot or to first request for post-operative analgesia. The quality of the block was the same in each group. Although there was no statistically significant difference in the mean time to peak plasma concentrations the mean peak concentration of ropivacaine was significantly higher than that of bupivacaine. There were no signs of systemic local anaesthetic toxicity in any patient in either group.

The successful use of regional anesthesia to prevent involuntary movements in a patient undergoing awake craniotomy

IMPLICATIONS

The authors demonstrate that the combination of single and continuous peripheral nerve blocks allows the control of involuntary movements in patients undergoing awake craniotomy.

[Sciatic nerve block: an new lateral mediofemoral approach. The value of its combination with a "3 in 1" block for invasive surgery of the knee]

OBJECTIVE

To describe a new midfemoral lateral approach for the sciatic nerve block. Its combination with the "3 in 1" block was tested for postoperative analgesia following major surgery of the knee.

STUDY DESIGN

Descriptive, anatomical and clinical study prospective.

PATIENTS

After testing in four unembalmed corpses the new approach was applied to 42 ASA 1-2 patients, in combination with a continuous "3 in 1" block.

METHODS

The new approach was analysed for reliability of the surface landmarks (a line drawn from the posterior margin of the greater trochanter towards the knee and parallel to the femur) and block extent assessed on the foot. Its combination with the "3 in 1" block was evaluated with a visual analogue scale (VAS) scoring, for postoperative analgesia after total knee arthroplasty.

RESULTS

The sciatic nerve was located in less than 10 min. A block of the sciatic nerve was fully achieved in all patients. Its median duration was 16 h. The median VAS score at rest was 0 mm (sciatic bloc + continuous block "3 in 1"), but increased to 40 mm (block "3 in 1" alone).

CONCLUSION

The new lateral midfemoral sciatic block is easy to master. Combined with a continuous "3 in 1" block, it provides excellent analgesia during the early postoperative period after major surgery of the knee.

Comparison of intrathecal morphine and continuous femoral 3-in-1 block for pain after major knee surgery under spinal anaesthesia

Major knee surgery is associated with moderate or severe post-operative pain. Intrathecal morphine and continuous femoral 3-in-1 block were compared prospectively in 40 patients for pain after major knee surgery under spinal anaesthesia, with 4 mL isobaric 0.5% bupivacaine. In a random order, 20 patients received preservative free morphine 0.3 mg mixed with spinal bupivacaine. In 20 patients, following spinal anaesthesia with only bupivacaine, femoral 3-in-1 block was performed post-operatively with 0.5% bupivacaine 2 mg kg-1. The block was continued via a catheter with 0.25% bupivacaine 0.1 mL h-1 kg-1 until the next morning (24 h after induction of spinal anaesthesia). Intramuscular oxycodone was given as a rescue analgesic in all patients. Two patients from the femoral group were excluded due to technical failure. Three patients in the morphine group and one patient in the femoral group did not need any additional oxycodone. In the morphine group on average 2.8 (range 0-7) and in the femoral group 3.2 (0-5) additional doses of oxycodone were needed during the 24 h observation period. The mean pain scores were significantly lower in the morphine group at 9 and 12 h into the 24-h trial. Itching was seen only in the morphine group (40% of the patients). Other side effects were similar in the two groups. All patients were satisfied with their pain therapy. Both intrathecal morphine and femoral 3-in-1 block alone were insufficient for the treatment of severe pain after major knee surgery.

Femoral nerve block as an alternative to parenteral narcotics for pain control after anterior cruciate ligament reconstruction

Anterior cruciate ligament (ACL) reconstruction is associated with significant postoperative pain, usually requiring parenteral narcotics. A prospective study of arthroscopically assisted autograft patellar tendon ACLR was initiated using Winnie's "three-in-one" femoral nerve block (FNB) as the primary means of postoperative pain control. Patient satisfaction and absence of parenteral narcotic use indicated clinical success. Of 24 patients studied, 92% had no parenteral narcotics administered following FNB. Ninety-five percent of patients believed FNB was beneficial and would request another. The average duration of pain control was 29 hours and the majority of patients (79%) believed discharge was possible within 23 hours. There were two patients who failed to respond to FNBs (8%) and no major complications. FNB is a safe, reliable, and effective form of analgesia following ACLR, eliminating the need for parenteral narcotics.

Posterior approach to the lumbar plexus combined with a sciatic nerve block using lidocaine

A combination of lumbar plexus block, by a posterior technique, and sciatic nerve block can be a useful technique for outpatient anaesthesia. The purpose of this study was to examine the clinical characteristics of these blocks using lidocaine and to measure the serum lidocaine concentrations. Forty-five patients, undergoing lower extremity surgery, were studied. Sciatic nerve and lumbar plexus blocks were made with lidocaine, 680 mg with adrenaline 0.3 mg. For each patient the following data were collected: weight, age, sex, site of surgery, time to perform each block, needle depth, speed of onset of the sensory and motor blocks in the territories of the sciatic, femoral, obturator and lateral cutaneous (sensory) nerves and postoperative analgesic requirements. Lidocaine serum concentrations were measured in ten of these patients at 0, 2, 5, 10, 30, 60, 90 and 120 min after the second block. Analgesia was complete in 88% (40/45) of the patients. The remaining five patients needed analgesics (fentanyl 150 micrograms or less). Despite the high dose of lidocaine, the serum concentrations were within safe limits (mean +/- SD) (CMAX = 3.66 +/- 2.21 micrograms.ml-1). Only one patient had a serum concentration > 5 micrograms.ml-1 (CMAX = 9.54 micrograms.ml-1). This was associated with a contra-lateral extension of the block. We conclude that this combination of blocks is a valuable alternative for unilateral lower extremity anaesthesia. However, clinicians must be aware of the implications of a contra-lateral extension of the block.