The effectiveness of ambulatory continuous popliteal sciatic nerve blockade on patient-reported overall benefit of analgesia in patients undergoing foot or ankle surgery (CAREFREE trial); a randomized, open label, non-inferiority trial.

STUDY OBJECTIVE: Management of pain after foot and ankle surgery remains a concern for patients and healthcare professionals. This study determined the effectiveness of ambulatory continuous popliteal sciatic nerve blockade, compared to standard of care, on overall benefit of analgesia score (OBAS) in patients undergoing foot or ankle surgery. We hypothesized that usage of ambulatory continuous popliteal sciatic nerve blockade is non-inferior to standard of care. DESIGN: Single center, randomized, non-inferiority trial. SETTING: Tertiary hospital in the Netherlands. PATIENTS: Patients were enrolled if ≥18 years and scheduled for elective inpatient foot or ankle surgery. INTERVENTION: Patients were randomized to ambulatory continuous popliteal sciatic nerve blockade or standard of care. MEASUREMENTS: The primary outcome was the difference in OBAS, which includes pain, side effects of analgesics, and patient satisfaction, measured daily from the first to the third day after surgery. A non-inferiority margin of 2 was set as the upper limit for the 90% confidence interval of the difference in OBAS score. Mixed-effects modeling was employed to analyze differences in OBAS scores over time. Secondary outcome was the difference in opioid consumption. MAIN RESULTS: Patients were randomized to standard of care (n = 22), or ambulatory continuous popliteal sciatic nerve blockade (n = 22). Analyzing the first three postoperative days, the OBAS was significantly lower over time in the ambulatory continuous popliteal sciatic nerve blockade group compared to standard of care, demonstrating non-inferiority (-1.9 points, 90% CI -3.1 to -0.7). During the first five postoperative days, patients with ambulatory continuous popliteal sciatic nerve blockade consumed significantly fewer opioids over time compared to standard of care (-8.7 oral morphine milligram equivalents; 95% CI -16.1 to -1.4). CONCLUSIONS: Ambulatory continuous popliteal sciatic nerve blockade is non-inferior to standard of care with single shot popliteal sciatic nerve blockade on patient-reported overall benefit of analgesia.

Adductor canal block techniques do not lead to involvement of sciatic nerve branches: a radiological cadaveric study.

INTRODUCTION: Low and high volume mid-thigh (ie, distal femoral triangle) and distal adductor canal block approaches are frequently applied for knee surgical procedures. Although these techniques aim to contain the injectate within the adductor canal, spillage into the popliteal fossa has been reported. While in theory this could improve analgesia, it might also result in motor blockade due to coverage of motor branches of the sciatic nerve. This radiological cadaveric study, therefore, investigated the incidence of coverage of sciatic nerve divisions after various adductor canal block techniques. METHODS: Eighteen fresh, unfrozen and unembalmed human cadavers were randomized to receive ultrasound-guided distal femoral triangle or distal adductor canal injections, with 2 mL or 30 mL injectate volume, on both sides (36 blocks in total). The injectate was a 1:10 dilution of contrast medium in local anesthetic. Injectate spread was assessed using whole-body CT with reconstructions in axial, sagittal and coronal planes. RESULTS: No coverage of the sciatic nerve or its main divisions was found. The contrast mixture spread to the popliteal fossa in three of 36 nerve blocks. Contrast reached the saphenous nerve after all injections, whereas the femoral nerve was always spared. CONCLUSIONS: Adductor canal block techniques are unlikely, even when using larger volumes, to block the sciatic nerve, or its main branches. Furthermore, injectate reached the popliteal fossa in a small minority of cases, yet if a clinical analgesic effect is achieved by this mechanism is still unknown.

A radiological cadaveric study of obturator nerve involvement and cranial injectate spread after different approaches to the fascia iliaca compartment block.

Whether the fascia iliaca compartment block (FICB) involves the obturator nerve (ON) remains controversial. Involvement may require that the injectate spreads deep in the cranial direction, and might thus depend on the site of injection. Therefore, the effect of suprainguinal needle insertion with five centimeters of hydrodissection-mediated needle advancement (S-FICB-H) on ON involvement and cranial injectate spread was studied in this radiological cadaveric study. Results were compared with suprainguinal FICB without additional hydrodissection-mediated needle advancement (S-FICB), infrainguinal FICB (I-FICB), and femoral nerve block (FNB). Seventeen human cadavers were randomized to receive ultrasound-guided nerve block with a 40 mL solution of local anesthetic and contrast medium, on both sides. Injectate spread was objectified using computed tomography. The femoral and lateral femoral cutaneous nerves were consistently covered when S-FICB-H, S-FICB or FNB was applied, while the ON was involved in only one of the 34 nerve blocks. I-FICB failed to provide the same consistency of nerve involvement as S-FICB-H, S-FICB or FNB. Injectate reached most cranial in specimens treated with S-FICB-H. Our results demonstrate that even the technique with the most extensive cranial spread (S-FICB-H) does not lead to ON involvement and as such, the ON seems unrelated to FICB. Separate ON block should be considered when clinically indicated.

Viscoelastic Testing in Trauma.

Traumatic-induced coagulopathy (TIC) is a complex condition which develops both as a response to trauma as well as to clinical care interventions. Accurate and timely diagnostics are necessary to enable therapy aimed at correction of TIC. Viscoelastic hemostatic assays (VHA) are increasingly recognized for their potential to diagnose TIC as well as for guidance of treatment. This narrative review focuses on the evidence of the use of VHAs to diagnose TIC, to monitor efficacy of treatment of TIC during bleeding and to prognosticate outcome. Pitfalls of the use of VHA are also discussed.

Minimum local anesthetic volumes for a selective saphenous nerve block: a dose-finding study.

BACKGROUND: Saphenous nerve block contributes to analgesia after knee and lower leg surgery. However, literature reports a wide range of volumes of local anesthetic being used for this block. METHODS: A non-randomized controlled trial in a single university hospital in March 2015. Eighteen healthy volunteers (ASA 1 status, aged 27-43 years; male-to-female ratio 11/7) were needed to determine the minimum local anesthetic volume (MLAV) of mepivacaine 2% using the Dixon up-and-down method to achieve a selective ultrasound-guided saphenous nerve block. The primary endpoint MLAV (ED50 and ED95) for an ultrasound-guided saphenous nerve block were determined. The secondary endpoints were the position of the saphenous nerve, block onset and duration of action, cutaneous spread of the block, and the occurrence of femoral nerve motor block. RESULTS: The measured MLAV dose that was effective in 50% of cases (ED50) for a complete saphenous nerve block was 1.5 mL; the calculated MLAV dose for 95% of cases (ED95) was 1.9 mL. The saphenous nerve was encountered in almost all cases on the anterior/anteromedial aspect of the femoral artery. We found no correlation between local anesthetic volume and the onset or duration of the block. Cutaneous spread of the nerve block was observed on the anteromedial aspect of the lower leg, with considerable individual variation between individuals in the study. No femoral motor block was observed. CONCLUSIONS: For a selective ultrasound-guided saphenous nerve block, the ED95 MLAV of mepivacaine 2% is 1.9 mL.

Hemorrhagic-Induced Cardiovascular Complications During Reamer-Irrigator-Aspirator-Assisted Femoral Nonunion Treatment.

UNLABELLED: The reamer-irrigator-aspirator (RIA) is a device that has recently been developed to retrieve bone graft from the medullary canal of the femur and the tibia. As for most new surgical procedures, complications arise as part of the learning curve and/or imperfections in the design or technique. To increase awareness of potential complications and to prevent unnecessary harm to the patient, new complications need to be reported. We present case reports of 2 patients who developed severe intraoperative cardiac events presumably caused by excessive and rapid blood loss during RIA bone graft harvesting. This complication has not been described before. Increased awareness of excessive blood loss and subsequent cardiac events during an RIA procedure is warranted. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Effects of a hospital-wide introduction of a massive transfusion protocol on blood product ratio and blood product waste.

BACKGROUND: Massive transfusion protocols (MTPs) are increasingly used in the transfusion practice and are developed to provide the standardized and early delivery of blood products and procoagulant agents and to supply the transfusion of blood products in a well-balanced ratio. AIM: The aim of this study was to investigate the effect of a hospital-wide introduction of an MTP on blood product ratio and a waste of blood products. MATERIALS AND METHODS: Retrospective analysis was performed to compare the transfusion practice in massive bleeding patients before and after the introduction of an MTP and between the use of an MTP and transfusion off-protocol. Massive bleeding was defined as an administration of ≥5 units of red blood cells (RBCs) within 12 h. RESULTS: Of 547 massively transfused patients, 192 patients were included in the pre-MTP period and 355 patients in the MTP period. The ratio of RBC to fresh frozen plasma (FFP) and the platelets transfused shifted significantly toward 1:1:1 in the MTP period (P = 0.012). This was mainly caused by a shift in RBC: FFP ratio (P = 0.014). An increase in the waste of blood products was observed, most notably FFPs (P = 0.026). Extending the storage time after thawing reduced the waste of FFPs from 11% to 4%. CONCLUSION: Hospital-wide introduction of an MTP is an adequate way to achieve a well-balanced transfusion ratio of 1:1:1. This comes at the cost of an increase in the waste of FFPs, which is lowered after extending the duration of storage time after thawing.