New ultrasound-guided capsular blocks for hip surgery: A narrative review

Surgery on the hip joint is very common. Improving pain management has been and is one of the fundamental pillars to optimize the functional recovery of patients. To do this, we must design a multimodal anesthetic-analgesic plan that covers the entire perioperative period. Peripheral nerve blocks and fascial blocks are an important component of multimodal analgesic strategies. Traditional blocks have moderate efficacy, prolonged motor impairment, and increased risk of falls. As an alternative, capsular blocks ("ileopsoas plane block" or "IPB" and pericapsular nerve group block or "PENG block") have recently been described that aim to avoid motor impairment while maintaining optimal analgesic efficacy. The objective of this review is to describe the new capsular blocks and to analyze whether they allow to improve postoperative analgesia and promote functional recovery with fewer complications, based on the innervation of the hip. To do this, a bibliographic review was carried out in the PubMed, Embase and Cochrane Library databases from January 2018 to June 2020.