The continuous development of medicine in most fields requires physicians to apply the latest methods and technology to ensure patients\' safety. In the field of anesthesiology we are pioneers in the application of measures that guarantee the security of our patients, making possible the greatest reduction in mortality seen among all other specialties. This objective has been achieved thanks to the introduction of changes such as the one presented in this review article. The specific NRFit® connections for neuraxial and other regional anesthesia applications prevent wrong route medication errors to occur. These medication errors have been related to a high morbidity and mortality rate. This article reviews this new technology based in our own two-year experience at Hospital Universitario Príncipe de Asturias (Alcalá de Henares, Madrid) as well as a literature review using PubMed, UpToDate and ClinicalKey.

The report of anesthetic technique failure is crucial and the etiology of the problem should be determined. We describe a case of locoregional anesthesia failure, in which, after excluding its most common causes, the resistance to local anesthetics was considered as the most probable clinical hypothesis. For this reason, a genetic test was performed, as well as the efficacy of other local anesthetics was evaluated, constituting a different approach in the cases of locoregional anesthesia failure. True resistance to local anesthetics is difficult to diagnose so information about this is scarce in the literature. One of the proposed causes is a mutation of sodium channels where local anesthetics bind. If not recognized, the application of locorregional anesthesia in this patient\'s condition can lead to unpleasant experiences and unnecessary risks, related to toxic levels of local anesthetics. For this reason, the resistance to local anesthetics should be always precluded in cases of strong clinical suspicion. This approach could be applied in similar cases.

The combination of drugs and routes of administration produces a synergistic effect, and one of the most important components of multimodal analgesic strategies are, therefore, nerve blocks for pain management. The effect of a local anaesthetic can be prolonged by administering an adjuvant. In this systematic review, we included studies on adjuvants associated with local anaesthetics in peripheral nerve blocks published in the last 5 years in order to evaluate their effectiveness. The results were reported according to the PRISMA guidelines. The 79 studies selected using our criteria showed a clear prevalence of dexamethasone (n=24) and dexmedetomidine (n=33) over other adjuvants. Different meta-analyses comparing adjuvants suggest that dexamethasone administered perineurally achieves superior blockade with fewer side effects than dexmedetomidine. Based on the studies reviewed, we found moderate evidence to recommend the use of dexamethasone as an adjuvant to peripheral regional anaesthesia in surgeries that can cause moderate to severe pain.

OBJECTIVE: Surgery for an ingrown toenail of the great toe is a common procedure that requires an anesthetic neuromuscular blockade of the entire digit. Various digital block techniques have been described, but no evidence-based recommendations on the best choice have emerged. We aimed to compare the V block to the H block in this type of surgery.
METHODS: Multicenter randomized clinical trial in patients undergoing onychocryptosis surgery between February 2018 and February 2020. We recorded sex, age, foot intervened, type of blockade used (H block or V block), efficacy 10 and 20minutes after injection of the anesthetic, and number of attempts.
RESULTS: A total of 140 surgeries to treat ingrown toenails were assigned to 2 groups (H block or V block) of 70 patients each. The same anesthetic, dose, and volume were used in all cases. The V technique produced a better neuromuscular block in 7.2% more cases at 10minutes and in 12.8% more at 20minutes.
CONCLUSIONS: Both block techniques are safe and effective. The V block is a good alternative to the H block in patients undergoing surgery to treat an ingrown toenail.

OBJECTIVE: Surgery for an ingrown toenail of the great toe is a common procedure that requires an anesthetic neuromuscular blockade of the entire digit. Various digital block techniques have been described, but no evidence-based recommendations on the best choice have emerged. We aimed to compare the V block to the H block in this type of surgery.
METHODS: Multicenter randomized clinical trial in patients undergoing onychocryptosis surgery between February 2018 and February 2020. We recorded sex, age, foot intervened, type of blockade used (H block or V block), efficacy 10 and 20min after injection of the anesthetic, and number of attempts.
RESULTS: A total of 140 surgeries to treat ingrown toenails were assigned to 2 groups (H block or V block) of 70 patients each. The same anesthetic, dose, and volume were used in all cases. The V technique produced a better neuromuscular block in 7.2% more cases at 10min and in 12.8% more at 20min.
CONCLUSIONS: Both block techniques are safe and effective. The V block is a good alternative to the H block in patients undergoing surgery to treat an ingrown toenail.

Multimodal analgesia provides quality analgesia, with fewer side effects due to the use of combined analgesics or analgesic techniques. Regional anaesthesia plays a fundamental role in achieving this goal. The different techniques of regional anaesthesia that include both peripheral and central blocks in either a single dose or in continuous infusion help to modulate the nociceptive stimuli that access the central level. The emergence of the ultrasound as an effective system to perform regional anaesthesia techniques has allowed the development of new regional anaesthesia techniques that formerly could not be carried out since only neurostimulation or skin references were used. It is essential to take into account that even with effective blocking it is advisable to associate other drugs by other routes, in this way we will be able to reduce the required doses individually and attempt to achieve a synergistic, not purely additive, effect.

BACKGROUND: Arterial hypotension is the most frequent adverse effect of subarachnoid anaesthesia in the elderly sustaining a femoral proximal fracture. Decreasing the local anaesthetic dose reduces the incidence of hypotension but shortens sensory block duration that could be insufficient in some surgical procedures. Sensory block duration could be prolonged using hypobaric local anaesthetics. We evaluated whether low hypobaric bupivacaine doses were adequate for this type of surgery while maintaining the haemodynamic stability.
METHODS: A prospective, randomized, double blinded study was designed. Patients over 65 years old, sustaining traumatic hip fracture, were assigned to one of two groups: B0.5 group, hypobaric bupivacaine 7.5mg 5mg/ml (control group), and B0.25 group, hypobaric bupivacaine 3.75 mg 2.5mg/ml (study group). After subarachnoid injection, sensory level and motor blockade degree were registered, as were blood pressure, and heart rate at basal time and at 2, 5, 10, 15, 20 and 30 min after injection. The doses of vasopressor needed were registered as well. Surgical conditions and the duration of the surgical procedure-whether rescue analgesia or anaesthesia was needed-and sensory level regression to T12, were registered as well.
RESULTS: Sixty four patients was the calculated sample size. The study was stopped in an interim analysis because an elevated number of patients in the B0.25 group needed iv rescue anaesthesia. In the analyzed cases, blood pressure was significantly lower in the B0.5 group at the 15 and 30 min measurements. Vasopressor drugs needs were similar between groups [ephedrine accumulated mean (SD) doses 11.4 (5.2) mg vs. 9.1 (2.7) mg, p=0.045)]. Sensory block regression to T12 was faster in the B0.25 group, [(mean (SD) 68.2 (29.0) min vs. 112.8 (17.3) min in the B0.5 group, p<0.05]. Five out of 19 patients in the B0.25 group needed intravenous anaesthesia rescue before surgery started.
CONCLUSIONS: Lowering hypobaric bupivacaine dose to 3.75 mg in subarachnoid anaesthesia for hip fracture repair surgery in elderly patients decrease intraoperative blood pressure, but in an important number of patients intravenous anaesthesia rescue was needed and preclude recommendation.

Intravenous regional anesthesia is a widely used technique for brief surgical interventions, primarily on the upper limbs and less frequently, on the lower limbs. It began being used at the beginning of the 20th century, when Bier injected procaine as a local anesthetic. The technique to accomplish anesthesia has not changed much since then, although different drugs, particularly long-acting local anesthetics, such as ropivacaine and levobupivacaine in low concentrations, were introduced. Additionally, drugs like opioids, muscle relaxants, paracetamol, neostigmine, magnesium, ketamine, clonidine, and ketorolac, have all been investigated as adjuncts to intravenous regional anesthesia, and were found to be fairly useful in terms of an increased onset of operative anesthesia and longer lasting perioperative analgesia. The present article provides an overview of current knowledge with emphasis on long-acting local anesthetic drugs.