Keywords
Regional anesthesia, general anesthesia, hip replacement, knee replacement
Regional anesthesia, general anesthesia, hip replacement, knee replacement
The discussion on the optimal anesthetic technique for most surgical procedures regarding the use of regional anesthetic versus general anesthetic techniques has been going on for decades. In hip and knee replacement, several randomized trials performed several decades ago were in favor of spinal or epidural analgesia1,2. This is probably explained by the positive physiological effects of the provided afferent blockade with better initial pain relief, a reduced endocrine metabolic response, and sympathetic blockade with less blood loss and increased leg blood flow, all resulting in reduced cardiopulmonary and thromboembolic morbidity, but at the potential cost of reduced capability for early postoperative mobilization, urinary bladder dysfunction, and rare but potentially severe neurological complications.
In recent years, several large epidemiological studies based on the large US databases (Premier and National Surgical Quality Improvement Program) have supported the old studies by demonstrating less postoperative morbidity when using regional anesthetic techniques2–7. However, these large-scale studies have little or no information on the type of general anesthesia, perioperative pain management, or details on the provided regional anesthetic technique. Furthermore, information on the care principles regarding the use of the fast-track methodology8 has not been provided, and most importantly comparisons have not been made on a randomized basis, thereby introducing a potential large selection bias. More recent reviews from randomized studies, but again without exact data on care principles and pain management, have questioned the benefits of regional anesthesia versus general anesthesia9 or even a higher risk for cardiovascular complications with neuraxial anesthesia10. In conclusion, the jury is still out for conclusive evidence for the optimal choice of regional versus general anesthetic techniques for knee and hip arthroplasty.
The goal of this brief review is to update the literature and discuss the potential for a more balanced view regarding the choice of anesthesia for hip and knee arthroplasty within a fast-track setup8, in which length of stay (LOS) before going home is now usually between 1 and 3 days11–13 and in which previous data have not shown firm differences between the two anesthetic techniques or in selected patient groups2–7,9.
Recently, two relatively small randomized studies (n = 120 in each) have compared modern target-controlled infusion with propofol and remifentanil versus a conventional spinal anesthesia (without opioids), within a fast-track setup and expected LOS of around 2 days, and with additional multimodal oral opioid-sparing analgesia14,15. These two studies showed no clinically relevant differences in functional recovery outcomes, LOS, or side effects regarding urinary bladder dysfunction and mobilization. However, after the initial few postoperative hours with residual effects of the spinal anesthesia, there were minor but probably not clinically relevant advantages in analgesia and opioid requirements in the general anesthesia group. Though of interest because of the modern general anesthesia technique and fast-track setup, these studies obviously cannot answer the important question about safety issues and potential differences in postoperative morbidity between the two anesthetic techniques but merely serve as a stimulus to perform the required large comparative studies.
Epidural analgesia should not be used routinely in fast-track total hip arthroplasty (THA) or total knee arthroplasty (TKA) because of the limited analgesic effect, especially in comparison with local wound infiltration (local infiltration analgesia, or LIA) in TKA16 combined with the potential for adverse effects such as urinary retention, pruritus, hypotension, and motor blockade17,18, all of which delay recovery.
Spinal anesthesia should be performed using only local anesthetics, as intrathecal opioids increase the risk of urinary retention, pruritus, and respiratory depression19 unless low doses (less than 200 µg) are used, and may not have superior analgesic efficacy compared with LIA in TKA16,20. Recommendations on the optimal dosage of the various types of local anesthetics are beyond the scope of this review. However, one of the challenges in spinal anesthesia for fast-track THA and TKA is optimal titration to provide sufficient analgesia during surgery without a recovery delay due to adverse effects, including impairment to motor function. This requires a strict focus on time spent for preparation and surgery, where a dosage of local anesthetic that is too low may result in the need for supplemental intravenous analgesics (opioids) or conversion to general anesthesia during surgery. However, doses as low as 5 mg bupivacaine have been proven sufficient for 60-minute procedures without the need for conversion to general anesthesia, but in combination with femoral and sciatic nerve blocks21 and their possible negative implications for motor function and recovery.
General anesthesia imposes various degrees of potential risks related mainly to airway management and respiration (dental and oral soft tissue injuries, vocal cord trauma, barotrauma from positive pressure ventilation, aspiration, and so on) and circulation (negative inotropic and chronotropic cardiac effects from anesthetics)4,6,7. Complications to spinal and epidural anesthesia also include hypotension due to the vasodilatory effect of the sympathetic blockade, in addition to the rare but potentially serious risk of compressive neuraxial hematoma. However, this occurs after spinal anesthesia in a maximum of 1 out of 775,000 procedures but in 1 out of 9000 to 1 out of 26,000 epidural procedures, again emphasizing that epidural should not be used22–24. The occurrence of neurological deficits from neuraxial blockade should be held against the overall risk of nerve injury after THA (0.08% to 1.7% in larger series) and TKA (0.3% to 0.9% in larger series)25. Comparison of the risk profiles for adverse events after general and spinal anesthesia needs to take into account that the choice of anesthesia and subsequent complications are affected mainly by patient characteristics. This is a main bias in the current large nationwide database studies reporting significantly higher complication rates after general anesthesia4,6,7. There is general agreement that neuraxial anesthesia may lead to bladder dysfunction in the perioperative period, even in patients undergoing THA and TKA26–29. So far, preoperative selection criteria, including preoperative urinary bladder function, have failed to solve the problem, but potentially postoperative catheterization may be avoided or reduced by using a lower-dose spinal anesthesia30. Furthermore, a higher ultrasound-verified bladder volume before catheterization may reduce catheterization, but the literature is inconclusive27. In the two recent fast-track modern anesthesia randomized series14,15, no differences in need for urinary catheterization with well-defined criteria were found.
In summary, there is a need for large-scale randomized studies with well-defined criteria for urinary bladder catheterization to demonstrate potential differences between the two anesthetic techniques. Importantly, such studies need to provide multimodal opioid-sparing analgesia since opioids may have a negative effect on urinary bladder function27.
Improvements in overall perioperative care regarding anesthesia, analgesia, fluid management, nursing care, and rehabilitation have led to a pronounced reduction of LOS to about 1 to 3 days with return to home11–15 and more recently even the potential to perform THA and TKA on an outpatient basis in selected patients31–33. A common feature of previous randomized studies as well as the large epidemiological studies2–7 is the lack of detailed information about the perioperative management and the two anesthetic techniques, including patient characteristics. Furthermore, the epidemiological studies rely on diagnostic codes, which may not always be exact. Although a balanced view of all available data from within a reasonably recent time frame may support the use of regional anesthesia, there is a severe need for large-scale prospective randomized controlled trials to compare general versus spinal anesthesia, knowing that the choice of anesthesia represents only one of the many factors that influence outcome. In this context, the focus must include potential identification of subgroups of patients who may or may not benefit from a given anesthetic procedure. Such studies must use an evidence-based approach when choosing the two anesthetic techniques, especially within the context of a fast-track setup with provision of an optimized multimodal, oral opioid-sparing analgesia to facilitate early mobilization and reduce adverse events, including the possibility for early mobilization and urinary bladder dysfunction34. Thus, most previous studies have not included gabapentinoids, which may be appropriate in hip replacement35 but not in knee replacement36,37, and preoperative high-dose glucocorticoid may provide major analgesic effects with reduced opioid use and side effects38,39. Furthermore, the use of high-volume LIA is evidence based in TKA but not in THA16. Also, future studies should include early (within a few hours) mobilization, which may be important to reduce thromboembolic complications40 that may be independent of anesthetic technique.
In summary, the recent development of optimized general and regional anesthetic techniques together with advances in multimodal opioid-sparing analgesia combined with the fast-track methodology may provide an opportunity in a large randomized study to answer the old question of whether regional anesthesia is better than general anesthesia41.
Views | Downloads | |
---|---|---|
F1000Research | - | - |
PubMed Central
Data from PMC are received and updated monthly.
|
- | - |
Competing Interests: No competing interests were disclosed.
Competing Interests: No competing interests were disclosed.
Alongside their report, reviewers assign a status to the article:
Invited Reviewers | ||
---|---|---|
1 | 2 | |
Version 1 15 Dec 15 |
read | read |
Provide sufficient details of any financial or non-financial competing interests to enable users to assess whether your comments might lead a reasonable person to question your impartiality. Consider the following examples, but note that this is not an exhaustive list:
Sign up for content alerts and receive a weekly or monthly email with all newly published articles
Already registered? Sign in
The email address should be the one you originally registered with F1000.
You registered with F1000 via Google, so we cannot reset your password.
To sign in, please click here.
If you still need help with your Google account password, please click here.
You registered with F1000 via Facebook, so we cannot reset your password.
To sign in, please click here.
If you still need help with your Facebook account password, please click here.
If your email address is registered with us, we will email you instructions to reset your password.
If you think you should have received this email but it has not arrived, please check your spam filters and/or contact for further assistance.
Comments on this article Comments (0)