Update on Current Enhanced Recovery After Surgery (ERAS) Pathways for hip and Knee Arthroplasty

A Review of the Literature

Om V. Patel, MD; Giles R. Scuderi, MD


Curr Orthop Pract. 2022;33(2):178-185. 

In This Article


Anesthesia Protocol

The ideal anesthetic for ERAS pathways should be tailored to optimize anesthetic depth while allowing for rapid awakening and safe mobilization.[21] Recent data from large patient databases may suggest that the pendulum appears to be swinging towards neuraxial anesthesia.[5] Regional neuraxial anesthesia, in contrast to general anesthesia, has demonstrated superior qualities with improved outcomes, decreased in-hospital mortality, pneumonia, and systemic infections.[21,39,40] Decreased risks of deep venous thrombosis (DVT), pulmonary embolism (PE), blood transfusion, and respiratory depression have also been noted.[40] However, contrasting evidence has been published demonstrating no clinically relevant difference in functional recovery, LOS, urinary complications, or mobilization when compared with modern general anesthesia.[13] Modern general anesthesia is the culmination of pharmacologic, drug delivery, and patient-monitoring advancements that allow for quicker recovery while minimizing side effects.[41] Furthermore, spinal anesthesia is not complication-free and can be rarely associated with spinal hematoma, epidural abscess, and nerve injury.[29] Because of this contrasting evidence, the ERAS Society in its latest consensus statement in 2020 strongly recommended either neuraxial or modern general anesthesia as appropriate for ERAS pathways with moderate evidence.[13]


Maintaining normothermia during the perioperative period is crucial to prevent complications and reduce the body's stress response,[42] which will aid in speedy recovery.[43] Hypothermia, defined as core body temperature below 36 degrees Celsius,[44] is associated with complications such as coagulopathy, increased blood loss,[45] wound infection, adverse cardiovascular effects, and altered metabolism.[28] Many methods of active and passive patient warming exist, two effective methods include resistive heating pads (electric pad that uses heat conduction) and forced-air warming (FAW) that heats the patient through convection of circulated warm air.[46] Some studies implicate FAW to increase the risk of surgical site infection because of disruption of laminar flow in the operating room.[46,47] However, based on this review of the current literature, the most effective and efficient method of warming is via forced warm air,[42,48] which ideally should begin preoperatively because there can be a large temperature drop between preoperative holding and induction of anesthesia.[42,44] To prevent this drop, a recent study by Kay et al.[49] found that forced-air gowns in the preoperative holding area reduced perioperative hypothermia by 30%. Current literature continues to support the maintenance of normothermia perioperatively, with forced-air methods proving the most effective.

Hemostasis and Blood Conservation

Hip and knee arthroplasty have long been associated with pronounced blood loss and blood transfusions. Allogenic blood transfusions are associated with delay of discharge and higher mortality[28] and can account for up to 90% of readmissions in enhanced recovery protocols.[50] However, the advent of tranexamic acid (TXA) and the utilization of blood-conserving techniques have significantly decreased postoperative transfusion rates and the associated morbidities.[28,51] The most recent consensus statement by the ERAS society provided a strong recommendation for the use of TXA for hip and knee arthroplasty.[13]

Many questions surrounding TXA administration persist regarding route of administration, dosage, timing, and its concurrent use on patients with known history of thromboembolism. To help answer these questions, evidence-based clinical practice guidelines were published in 2018 by consensus from the American Association of Hip and Knee Surgeons (AAHKS), the American Academy of Orthopedic Surgeons (AAOS), the Hip Society, the Knee Society, and the American Society of Regional Anesthesia and Pain Medicine (ASRA).[52] These consensus recommendations utilizing the AAOS systematic review methodology were based on high quality evidence and are summarized:

  1. Studies have shown that IV, topical, oral or combinations of TXA are effective strategies to reduce blood loss and need for transfusion without a clear superior route of administration.

  2. The dose of perioperative TXA was not found to significantly affect the reduction in blood loss or need for transfusion.

  3. No significant differences in blood loss or transfusion rate were seen in single versus repeat TXA dose administrations.

  4. The administration of TXA prior to incision, as opposed to after, reduces blood loss and need for transfusion.

  5. The use of TXA in patients with known thromboembolic events such as myocardial infarction (MI), cerebrovascular accident (CVA), transient ischemic attack (TIA), and/or vascular stent placement has been controversial.

However, these guidelines set forth in conjunction with the ASRA conclude with moderate evidence that these comorbidities do not increase the risk of adverse thromboembolic events during the perioperative episode of primary TJA. This final recommendation is provided with some uncertainty and disclaimer that the summation of an individual's risk profile must be taken into consideration. Further high-quality research in this area is indicated.[53]

A recent meta-analysis of 19 RCTs by Zhang et al.[53] concluded that closed suction drains were not superior to no drain. The drain group was found to have an increased risk of transfusion (RR 1.38) and a longer time to regain straight leg raise although there was no significant difference in total blood loss, hemoglobin drop, superficial wound infections, deep infections, LOS, or development of DVTs.[53] Bipolar cautery was found to be just as effective as conventional electrocautery in terms of blood loss, transfusion rates, LOS, and functional recovery in a prospective cohort study of tourniquetless primary TKAs.[54]