Over 350,000 total hip arthroplasties (THA) are performed annually in the United States. After these surgeries, adequate pain relief promotes postoperative ambulation, facilitates initiation of physiotherapy, and helps ensure optimal outcomes. It is also the right thing to do. The problem facing anesthesiologists is deciding how best to provide good analgesia while minimizing risks, side effects, and expense. Historically, epidural and spinal analgesia techniques were often chosen for hip and knee arthroplasty. Now, the nearly ubiquitous use of anticoagulation for prevention of deep vein thrombosis makes continuous epidural and (likely) other continuous deep block techniques impractical. So what is the best alternative option? In this issue of Anesthesia & Analgesia, Ilfeld and colleagues1 report a randomized, controlled trial comparing continuous proximal femoral nerve block and posterior lumbar plexus nerve blocks for analgesia following THA. In addition, all patients received scheduled long-acting opioids, and could also receive on-demand opioids. The 2 treatment groups reported similar pain scores, demonstrating noninferiority of the proximal femoral block to the lumbar plexus block technique under the conditions of the study. So, is proximal femoral block analgesia the nerve block solution to the problem of providing regional analgesia for an anticoagulated THA patient?
First, are either of these techniques compatible with anticoagulation? The latest American Society of Regional Anesthesia guideline on anticoagulation clearly discourages the use of continuous epidural or other “deep” block techniques when twice-daily low molecular weight heparin or other modern prophylactic agents will be used.2 The American Society of Regional Anesthesia guideline states, “For patients undergoing deep plexus or peripheral block, we recommend that recommendations regarding neuraxial techniques be similarly applied.” When warfarin will be used, the guideline recommends withdrawal of epidural catheters (and other “deep” catheters) only when the international normalized ratio (INR) is 1.5 or less. The usefulness of the INR during induction of warfarin anticoagulation has been questioned by the work of Benzon et al., who showed that soon after initiation of warfarin the INR overestimates the degree of anticoagulation.3 The prevailing wisdom appears to accept that femoral infusion blocks can be maintained during prophylactic anticoagulation. On the other hand, though the data are sparse on negative outcomes following lumbar plexus blocks in anticoagulated patients, we would not routinely place such a block in patients undergoing THA with modern anticoagulation.
Second, are there concerns other than efficacy that guide our selection of analgesic technique? Within the context of this study, femoral nerve blocks were as effective as posterior lumbar plexus blocks for pain relief after total hip arthroplasty. On the other hand, Ilfeld and colleagues observed that the femoral catheter group more often experienced a greater degree of quadricep weakness that decreased total ambulation time and appeared to increase the risk of falls than did the posterior lumbar plexus block group. The increased risk of falls with quadriceps weakness had been demonstrated by Ilfeld et al. and Sharma et al.4,5 Both groups reported an association among continuous peripheral nerve blocks, reduced quadriceps strength, and the risk of falling after knee and hip arthroplasty. For us, the decreased mobility that some patients experienced and the increased risk of falls would lead us to request that femoral blocks not be performed on us if we were to undergo a THA.
The study by Ilfeld and colleagues provides us with valuable and interesting new information. However, neither of the studied approaches seem optimal for a truly “fast track” recovery for the contemporary THA patient who will receive modern prophylactic anticoagulation and who will experience a postoperative length of stay as short as 48 hours. In such patients we find that a useful, simple anesthesia and analgesia strategy will include the use of spinal or epidural anesthesia and a single dose of spinal or epidural opioid (in the former case, intrathecal hydromorphone or morphine and in the latter case, extended-release epidural morphine).6–8 Such techniques provide excellent surgical anesthesia and 18 to 48 hours of postoperative analgesia, promote early ambulation (unencumbered by IV, epidural, or continuous nerve block infusions), and avoid some of the unwanted side effects of general anesthesia.9,10 On the other hand, a patient who requires hip surgery despite opioid tolerance, severe obstructive sleep apnea, or coagulation abnormalities would likely benefit from a proximally sited femoral nerve catheter and a reduced requirement for IV or oral opioids using the technique proposed by Dr. Ilfeld and colleagues. Finally, patients with hip fracture scheduled for open reduction internal fixation will experience less discomfort during positioning for placement of a femoral nerve catheter than for placement of a lumbar plexus catheter.11 Having an effective block that can be placed while these patients remain supine will represent an important new option.
Name: Yar Luan Yeap, MD.
Contribution: This author coauthored the editorial.
Attestation: Yar Luan Yeap approved the final manuscript.
Name: John F. Butterworth, MD.
Contribution: This author coauthored the editorial.
Attestation: John F. Butterworth approved the final manuscript.
1. Ilfeld BM, Mariano ER, Madison SJ, Loland VJ, Sandhu NS, Suresh PJ, Bishop ML, Kim E, Donohue MC, Kulidjian AA, Ball ST. Continuous femoral versus posterior lumbar plexus nerve blocks for analgesia after hip arthroplasty: a randomized, controlled study. Anesth Analg 2011;113:897–903
2. Horlocker TT, Wedel DJ, Rowlingson JC, Enneking FK, Kopp SL, Benzon HT, Brown DL, Heit JA, Mulroy MF, Rosenquist RW, Tryba M, Yuan CS. Regional anesthesia in the patient receiving antithrombotic or thrombolytic therapy: American Society of Regional Anesthesia and Pain Medicine evidence-based guidelines (3rd ed.). Reg Anesth Pain Med 2010;35:64–101
3. Benzon HT, Avram MJ, Benzon HA, Kirby-Nolan M, Nader A. Factor VII levels and international normalized ratios in the early phase of warfarin therapy. Anesthesiology 2010;112:298–304
4. Ilfeld BM, Duke KB, Donohue MC. The association between lower extremity continuous peripheral nerve blocks and patient falls after knee and hip arthroplasty. Anesth Analg 2010;111:1552–4
5. Sharma S, Iorio R, Specht LM, Davies-Lepie S, Healy WL. Complications of femoral nerve block for total knee arthroplasty. Clin Orthop Relat Res 2010;468:135–40
6. Fischer HB, Simanski CJ. A procedure-specific systematic review and consensus recommendations for analgesia after total hip replacement. Anesthesiology 2005;60:1189–202
7. Gwirtz KH, Young JV, Byers RS, Alley C, Levin K, Walker SG, Stoelting RK. The safety and efficacy of intrathecal opioid analgesia for acute postoperative pain: seven years' experience with 5969 surgical patients at Indiana University Hospital. Anesth Analg 1999;88:599–604
8. Kahl L, Parvizi J, Viscusi ER, Hozack WJ, Sharkey PF, Rothman RH. Lessons learned with extended-release epidural morphine after total hip arthroplasty. Clin Orthop Relat Res 2010;468:1082–7
9. Macfarlane AJ, Prasad GA, Chan VW, Brull R. Does regional anesthesia improve outcome after total hip arthroplasty? A systematic review. Br J Anaesth 2009;103:335–45
10. Chang CC, Lin HC, Lin HW, Lin HC. Anesthetic management and surgical site infections in total hip or knee replacement: a population-based study. Anesthesiology 2010;113:279–84
11. Chudinov A, Berkenstadt H, Salai M. Continuous psoas compartment block for anesthesia and perioperative analgesia in patients with hip fractures. Reg Anesth Pain Med 1999;24:563–8