Comparison of continuous epidural infusion of a local anesthetic and administration of systemic narcotics in the management of pain after total knee replacement surgery

Effectiveness of ERAS (Enhanced Recovery after Surgery) Protocol via Peripheral Nerve Block for Total Knee Arthroplasty

Peripheral nerve block (PNB) for patients with total knee arthroplasty (TKA) is one of the recommended interventions in ERAS protocols. However, most existing studies involved unilateral TKA (UTKA). As such, this study aimed to evaluate the effectiveness of PNB in terms of immediate postoperative analgesia, length of hospital stays (LOS), and early functional outcomes in both UTKA and simultaneous bilateral TKAs (BTKAs). We reviewed 236 patients who underwent primary TKA with PNB, with 138 and 98 being UTKA and BTKAs, respectively; those in the PNB group underwent femoral nerve and adductor canal block. The matched control and PNB groups—who received intravenous/epidural patient-controlled analgesia (IVPCA/PCEA) alone or IVPCA in addition to PNB after surgery, respectively—were compared. The VAS scores at rest until 48 h after surgery were significantly lower in PNB groups compared to those in the IVPCA groups. At 0– 6 h of activity, VAS scores of the UTKA with PNB group were also lower than the IVPCA group. Compared to PCEA groups, VAS scores at 0–6 h of activity were higher in both the UTKA and BTKAs with PNB groups. However, at 24–48 h at rest, the scores of those in the UTKA with PNB group were lower than those in the PCEA group. The control and experimental UTKA and BTKAs groups had similar LOS and functional outcomes at 90 days postoperatively. In primary TKA, PNB has great analgesic effects for immediate postoperative pain control, and represents a similar analgesic effect to epidural PCA.

Assessing outcome in postoperative pain trials: are we missing the point? A systematic review of pain-related outcome domains reported in studies early after total knee arthroplasty

ABSTRACT

The management of acute postoperative pain remains suboptimal. Systematic reviews and Cochrane analysis can assist with collating evidence about treatment efficacy, but the results are limited in part by heterogeneity of endpoints in clinical trials. In addition, the chosen endpoints may not be entirely clinically relevant. To investigate the endpoints assessed in perioperative pain trials, we performed a systematic literature review on outcome domains assessing effectiveness of acute pain interventions in trials after total knee arthroplasty. We followed the Cochrane recommendations for systematic reviews, searching PubMed, Cochrane, and Embase, resulting in the screening of 1590 potentially eligible studies. After final inclusion of 295 studies, we identified 11 outcome domains and 45 subdomains/descriptors with the domain "pain"/"pain intensity" most commonly assessed (98.3%), followed by "analgesic consumption" (88.8%) and "side effects" (75.3%). By contrast, "physical function" (53.5%), "satisfaction" (28.8%), and "psychological function" (11.9%) were given much less consideration. The combinations of outcome domains were inhomogeneous throughout the studies, regardless of the type of pain management investigated. In conclusion, we found that there was high variability in outcome domains and inhomogeneous combinations, as well as inconsistent subdomain descriptions and utilization in trials comparing for effectiveness of pain interventions after total knee arthroplasty. This points towards the need for harmonizing outcome domains, eg, by consenting on a core outcome set of domains which are relevant for both stakeholders and patients. Such a core outcome set should include at least 3 domains from 3 different health core areas such as pain intensity, physical function, and one psychological domain.

Effectiveness of 3-in-1 Continuous Femoral Block of Differing Concentrations Compared to Patient Controlled Intravenous Morphine for Post Total Knee Arthroplasty Analgesia and Knee Rehabilitation

We assessed the effectiveness of the 3-in-l continuous femoral block as a form of postoperative pain relief for unilateral total knee arthroplasty (TKA). Sixty patients undergoing elective unilateral TKA under subarachnoid block were randomized into three groups. Postoperative analgesia was provided with a continuous 3-in-l femoral nerve catheter with 0.15% ropivacaine in group A, a continuous 3-in-l femoral nerve catheter with 0.2% ropivacaine in group B, or patient controlled intravenous morphine in group C (control group). Groups A and B received patient controlled intravenous morphine pumps for rescue analgesia. Patients in each group were followed for 72 hours postoperatively. Five patients were excluded after randomization. In the remaining 55 patients there was no statistical difference in pain score between the groups. Total morphine use was highest in group C (P< 0.05). No appreciable difference could be found with sensorimotor blockade, morphine usage and satisfaction scores when comparing groups A and B. Femoral catheter dislodgement rate was 7.9%. There was no statistical difference between the groups when comparing the day of first ambulation and the time to discharge from the hospital. Satisfaction scores were higher in group A (P = 0.028) and group B (P = 0.002) compared to group C. We conclude that a continuous 3-in-l femoral nerve block with ropivacaine 0.15% or 0.2% for elective unilateral TKA has an opioid-sparing effect.

Potential superiority of periarticular injection in analgesic effect and early mobilization ability over femoral nerve block following total knee arthroplasty

PURPOSE

Pain management after total knee arthroplasty (TKA) should permit early knee mobilization with minimal pain. Periarticular injection (PAI) with local anaesthetics has been recently discussed as a protocol of pain control. The purpose of this review of the literature was to evaluate the efficacy of PAI in comparison with femoral nerve block (FNB).

METHODS

A literature search was performed in PubMed, EMBASE, the OVID database and the Cochrane Library databases. Risk of bias was assessed using the Cochrane collaboration tool. Outcomes of interest included narcotic consumption, pain score, early mobilization ability, length of stay and adverse effects or events.

RESULTS

Research identified 918 articles, of which six with a total of 284 knees, met the inclusion criteria and were eligible for the current study. Conflicting evidence was found in terms of narcotic consumption on the postoperative day 1 and early mobilization ability. Total narcotic consumption, pain score in the first 2 days after surgery, length of stay and adverse effects or events showed no difference between two groups. Lower pain score on the day of surgery was detected after PAI. When compared to continuous FNB, patients in PAI group showed a tendency to achieving better ability of early mobilization.

CONCLUSIONS

In consideration of its relatively simple practice and its potential in analgesic effects or early mobilization ability, PAI had superiority to FNB in the management of pain control after TKA. Before PAI could be widely used in clinical practice after TKAs, further investigations would be necessary to confirm or refute our observed results and to unify the protocol of PAI.

LEVEL OF EVIDENCE

I.

Femoral nerve block for patient undergoing total knee arthroplasty: Prospective, randomized, double-blinded study evaluating analgesic effect of perineural fentanyl additive to local anesthetics

BACKGROUND

The existence of peripheral opioid receptors and its effectiveness in peripheral nerve block remain controversial. The aim of this prospective, randomized, double-blinded study was to examine the analgesic effects of adding fentanyl to ropivacaine for continuous femoral nerve block (CFNB) using patient-controlled analgesia after total knee arthroplasty (TKA).

METHODS

The patients were divided into 2 groups, each with n = 40 in ropivacaine (R) group and n = 42 in R with fentanyl (R + F) group. After operation, the patients in each group received R + F and R alone via a femoral nerve catheter, respectively. We assessed the visual analog scale (VAS) pain immediately before administration (baseline) and at 15, 30, and 60 minutes on postanesthesia care unit (PACU), and resting and ambulatory VAS score up to 24 hours.

RESULTS

Overall, the average VAS scores in the R + F group were slightly lower than those of the R group. However, the VAS score differences between groups were not statistically significant, except for 30 minutes (P = 0.009) in PACU. R group showed higher supplemental analgesics consumption in average compared with R + F group, but not significant.

CONCLUSION

Additional fentanyl did not show prominent enhancement of analgesic effect in the field of CFNB after TKA.

[Efficacy of the fascia iliaca compartment block vs continuous epidural infusion for analgesia following total knee replacement surgery]

BACKGROUND AND OBJECTIVE

Total knee replacement causes moderate to severe postoperative pain. The aim of this trial was to compare postoperative analgesia from a fascia iliaca compartment block to continuous epidural analgesia following knee arthroplasty.

PATIENTS AND METHODS

Clinical trial enrolling patients in American Society of Anesthesiologists (ASA) classes 1 to 3 randomized to 2 groups. One group received spinal anesthesia plus a fascia iliaca compartment block with 0.1% bupivacaine at a rate of 10 mL/h. The second group received combined spinal-epidural anesthesia plus epidural analgesia with 0.1% bupivacaine in continuous infusion at a rate of 8 mL/h. Postoperative pain on a visual analog scale (VAS) at rest and on movement was recorded every 3 hours for the first 24 hours. Use of intravenous morphine and the adverse events were also recorded.

RESULTS

Forty patients (20 for each group) were enrolled. The distribution of age, weight, body mass index, sex, ASA class, duration of surgery, use of morphine, and the incidence of adverse effects were similar in the 2 groups. Postoperative VAS scores at rest and on movement were also similar. The incidence of arterial hypotension was higher in the epidural analgesia group.

CONCLUSIONS

The fascia iliaca compartment block and continuous epidural infusion are similarly efficient in providing postoperative analgesia for patients after total knee replacement. The fascia iliaca compartment block is associated with a lower incidence of postoperative hemodynamic complications. Early, safe rehabilitation is facilitated by both analgesic techniques.

Low cost continuous femoral nerve block for relief of acute severe cancer related pain due to pathological fracture femur

Pathological fractures in cancer patient cause severe pain that is difficult to control pharmacologically. Even with good pain relief at rest, breakthrough and incident pain can be unmanageable. Continuous regional nerve blocks have a definite role in controlling such intractable pain. We describe two such cases where severe pain was adequately relieved in the acute phase. Continuous femoral nerve block was used as an efficient, cheap and safe method of pain relief for two of our patients with pathological fracture femur. This method was proved to be quite efficient in decreasing the fracture-related pain and improving the level of well being.

Complications of femoral nerve block for total knee arthroplasty

Preemptive and multimodal pain control protocols have been introduced to enhance rehabilitation after total knee arthroplasty (TKA). We determined the complication rate associated with preoperative femoral nerve block (FNB) for TKA. Among 1018 TKA operations, we performed 709 FNBs using a single-injection technique into the femoral nerve sheath and confirming position with nerve stimulation before induction. After TKA, weightbearing as tolerated was initiated using a walker or crutches on postoperative Day 1. Twelve patients (1.6%) treated with FNB sustained falls, three (0.4%) of whom underwent reoperations. Five patients had postoperative femoral neuritis, which may have been secondary to the block. One patient had new onset of atrial fibrillation after FNB, and the TKA was postponed. Femoral nerve block before TKA is not a harmless intervention. We recommend postoperative protocols be modified for patients who have FNB to account for decreased quadriceps function in the early postoperative period, which can lead to falls.

LEVEL OF EVIDENCE

Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Continuous femoral nerve analgesia after unilateral total knee arthroplasty: stimulating versus nonstimulating catheters

BACKGROUND

Continuous femoral analgesia provides extended pain relief and improved functional recovery for total knee arthroplasty (TKA). Stimulating catheters may allow more accurate placement of catheters.

METHODS

We performed a randomized prospective study to investigate the use of stimulating catheters versus nonstimulating catheters in 41 patients undergoing TKA. All patients received i.v. patient-controlled anesthesia for supplementary pain relief. The principal aim of the trial was to examine whether a stimulating catheter allowed the use of lesser amounts of local anesthetics than a nonstimulating catheter. The additional variables we examined included postoperative pain scores, opioid use, side effects, and acute functional orthopedic outcomes.

RESULTS

Analgesia was satisfactory in both groups, but there were no statistically significant differences in the amount of ropivacaine administered; the median amount of ropivacaine given to patients in the stimulating catheter group was 8.2 mL/h vs 8.8 mL/h for patients with nonstimulating catheters, P = 0.26 (median difference -0.6; 95% confidence interval, -2.3 to 0.6). No significant differences between the treatment groups were noted for the amount of fentanyl dispensed by the i.v. patient-controlled anesthesia, numeric pain rating scale scores, acute functional orthopedic outcomes, side effects, or amounts of oral opioids consumed.

CONCLUSION

The use of stimulating catheters in continuous femoral nerve blocks for TKA does not offer significant benefits over traditional nonstimulating catheters.

Intermittent vs continuous administration of epidural ropivacaine with fentanyl for analgesia during labour †

BACKGROUND

Many years ago regular intermittent bolus administration of epidural local anaesthetic solution was recognized to produce more effective analgesia than continuous infusion, but only recently has the development of suitable pumps allowed the former technique's wider evaluation.

METHODS

In this randomized, double-blind trial, 40 primigravid patients had a lumbar epidural catheter inserted, and plain ropivacaine 0.2% 15-20 ml was titrated until analgesia and bilateral sensory block to T10 were produced (time zero). Patients were then given either an infusion of ropivacaine 2 mg ml(-1) with fentanyl 2 microg ml(-1) at 10 ml h(-1), or hourly boluses of 10 ml of the same solution. Pain, sensory block and motor block were measured frequently. If requested, additional 10 ml boluses of the study mixture were given for analgesia.

RESULTS

There were no differences between the two groups in patient characteristics, obstetric/neonatal outcome, or in sensory or motor block. A total of 12 (60%) patients in the continuous group required one or more additional boluses compared with 4 (20%) patients in the intermittent group (95% CI 9.6-61.7%, P=0.02). Therefore the intermittent group received a lower total drug dose than the infusion group (P=0.02). Duration of uninterrupted analgesia (time to first rescue bolus) was longer in the intermittent group (P<0.02).

CONCLUSIONS

The intermittent group required fewer supplementary injections and less drug to maintain similar pain scores, sensory and motor block compared with the continuous group. This represents a more efficacious mode of analgesia.

A Comparison of Epidural Analgesia With Combined Continuous Femoral-Sciatic Nerve Blocks After Total Knee Replacement

Epidural analgesia remains the "gold standard" of pain relief after total knee replacement. However, peripheral nerve block is gaining popularity because the incidence of side effects may be reduced. Our study tests this postulate. Sixty patients were prospectively randomized to receive either epidural infusion or combined continuous femoral and sciatic nerve blocks. Ropivacaine 2 mg/mL plus sufentanil 1 mug/mL was given either epidurally or through the femoral nerve catheter, and ropivacaine 0.5 mg/mL was given through the sciatic nerve catheter using elastomeric infusers (delivering 5 mL/h for 55 h). The primary outcome measure was the total incidence of side effects (urinary retention and moderate to severe degrees of dizziness, pruritus, sedation, and nausea/vomiting on the first postoperative day). Intensity of motor blockade, pain at rest and on mobilization, and rehabilitation indices were also registered for 72 h. One or more side effects were present in 87% of patients in the epidural group whereas only 35% of patients in the femoral and sciatic block groups were affected on the first postoperative day (P = 0.0002). Motor blockade was more intense in the operated limb on the day of surgery and the first postoperative day in the peripheral nerve block group (P = 0.001), whereas the non-operated limb was more blocked in the epidural group on the day of surgery (P = 0.0003). Pain on mobilization was well controlled in both groups and there were no differences in the length of hospital stay. Rehabilitation indices were similar. The results demonstrate a reduced incidence of side effects in the femoral/sciatic nerve block group than in the epidural group on the first postoperative day.

The effects of femoral nerve blockade in conjunction with epidural analgesia after total knee arthroplasty

Either epidural analgesia or femoral nerve blockade improves analgesia and rehabilitation after total knee arthroplasty. No study has evaluated the combination of femoral nerve blockade and epidural analgesia. In this prospective, randomized, blinded study we investigated combining femoral nerve blockade with epidural analgesia. Forty-one patients received a single-injection femoral nerve block with 0.375% bupivacaine and 5 microg/mL epinephrine; 39 patients served as controls. All patients received combined spinal-epidural anesthesia and patient-controlled epidural analgesia with 0.06% bupivacaine and 10 microg/mL hydromorphone. Average duration of epidural analgesia was 2 days. All patients received the same standardized physical therapy intervention. Median visual analog scale (VAS) scores with physical therapy were significantly lower for 2 days among patients who received a femoral nerve block versus controls: 3 versus 4 (day 1), 2.5 versus 4 (day 2); P < 0.05. Median VAS pain scores at rest were 0 in both groups on days 1 and 2. Flexion range of motion was improved on postoperative day 2 (70 degrees versus 63 degrees ; P < 0.05). No peripheral neuropathies occurred. We conclude that the addition of femoral nerve blockade to epidural analgesia significantly improved analgesia for the first 2 days after total knee arthroplasty.

Guidelines and alternatives for neuraxial anesthesia and venous thromboembolism prophylaxis in major orthopedic surgery

Neuraxial anesthesia during major orthopedic surgery, combined with venous thromboembolism prophylaxis, is generally safe and well tolerated, with potential benefits over general anesthesia. The risk of spinal/epidural hematoma, a rare but very serious complication, can be minimized by careful patient selection and attention to anesthetic technique. This risk is further reduced with the use of peripheral nerve blocks in place of neuraxial anesthesia.

Injectable microparticle-gel system for prolonged and localized lidocaine release. I.In vitro characterization

Current treatment protocol for postoperative pain is to infuse anesthetic solution around nerves or into the epidural space. This clinical practice is beset by the short duration of the anesthetic effect unless the infusion is continuous. Continuous infusion, however, requires hospitalization of the patients, thereby increasing medical costs. In addition, it also causes systemic accumulation of the drug. We reported herein a novel treatment for the postoperative pain by applying to the surgical site a biodegradable microsphere-gel system for prolonged and localized release of encapsulated anesthetic drugs. This lidocaine-containing biodegradable poly(D,L-lactic acid) (PLA) microsphere system, although being established previously by other investigators, was hindered by a burst release and a followed rapid release of the drug within several hours in vitro. In this article, we demonstrated that by a step-by-step modification of the formulation, prolonged release of lidocaine, up to several days in vitro, could be achieved. Differential scanning calorimetry revealed a lower glass transition temperature for these lidocaine-loaded microspheres comparing to that of lidocaine-free microspheres. This decreased Tg explained for the tendency of the lidocaine-loaded microspheres to physically fuse at higher temperatures. In vitro studies showed that microspheres, when loaded with 35% lidocaine, yielded a threefold increase in the degradation rate. The molecular weight of PLA of the drug-loaded microspheres was reduced by 50% within a period of 1 month. Based on the results (of prolonged lidocaine release and rapid PLA microsphere degradation), this lidocaine-loaded PLA microsphere system could offer a simple solution to the treatment of postoperative pain.

Epidural analgesia for pain relief following hip or knee replacement

BACKGROUND

Hip and knee replacement are common operative procedures to improve mobility and quality of life. Adequate pain relief is essential in the postoperative period to enable ambulation and initiation of physiotherapy. Lumbar epidural analgesia is a common modality for pain relief following these procedures. However, there is no systematic review of the evidence comparing the efficacy of epidural analgesia with other postoperative analgesic modalities. As the use of epidural analgesia may delay the initiation of anticoagulant thromboprophylaxis due to the potential risk of epidural hematoma, a synthesis of the evidence is necessary to determine whether or not alternative analgesic modalities are worse, equivalent, or better than epidural analgesia.

OBJECTIVES

Our objective is to answer the question: "Is lumbar epidural analgesia more efficacious than systemic analgesia or long-acting spinal analgesia for postoperative pain relief in patients after elective hip or knee replacement?"

SEARCH STRATEGY

MEDLINE, EMBASE, CINAHL, LILACS, and the Cochrane Controlled Trials Register were searched from their inception to June 2001. Reference lists of review articles and included studies were also reviewed for additional citations.

SELECTION CRITERIA

A study was included if it was a randomized or pseudo randomized controlled clinical trial of patients undergoing hip or knee replacement, in which postoperative lumbar epidural analgesia was compared to other methods for pain relief. Study selection was performed unblinded in duplicate.

DATA COLLECTION AND ANALYSIS

Data were collected unblinded in duplicate. Information on the patients, methods, interventions, outcomes (pain relief, postoperative function, length of stay) and adverse events were recorded. Methodological quality was assessed using a validated 5-point scale. Meta-analysis was conducted when sufficient data existed from two or more studies. Heterogeneity testing was performed using the Breslow-Day method. The fixed effects model was used unless heterogeneity was present, in which case, a random effects model was used. Continuous data were summarized as weighted mean differences (WMD) or standardized mean differences (SMD) with 95% confidence intervals (CI). Dichotomous data were summarized as odds ratios (OR) and numbers-needed-to-treat (NNT) or numbers-needed-to-harm (NNH) with their respective 95% CI. Graphical representation of continuous data used the MetaView program.

MAIN RESULTS

In the first four to six hours after surgery, patients receiving epidural analgesia had less pain at rest, based on visual analog scores (VAS), than patients receiving systemic analgesia (SMD -0.77; 95% CI -1.24 to -0.31). This effect was not statistically significant by 18 to 24 hours (SMD -0.29; 95% CI -0.73 to 0.16). These observations were based only on studies evaluating populations consisting of total knee replacements alone or mixed populations of total hip or total knee replacements. For pain relief with movement after surgery, patients receiving epidural analgesia reported lower pain scores than patients receiving systemic analgesia in all four studies examining these outcomes. The choice of epidural agents may also influence the extent to which epidural analgesia differs from systemic analgesia. The differences between epidural analgesia and systemic analgesia in the frequency of nausea and vomiting (OR 0.95; 95% CI 0.60 to 1.49) or depression of breathing (OR 1.07; 95% CI 0.45 to 2.54) were not statistically significant. Sedation occurred less frequently with epidural analgesia (OR 0.30; 95% CI 0.09 to 0.97) with a number-needed-to-harm of 7.7 (95% CI 3.5 to 42.0) patients for the systemic analgesia group. Retention of urine (OR 3.50, 95% CI 1.63 to 7.51; NNH 4.5, 95% CI 2.3 to 12.2), itching (OR 4.74, 95% CI 1.76 to 12.78; NNH 6.8, 95% CI 4.4 to 15.8), and low blood pressure (OR 2.78, 95% CI 1.15 to 6.72; NNH 6.7, 95% CI 3.5 to 103) were more frequent with epidural analgesia compared to systemic analgesia. There were insufficient numbers to draw conclusions on the edural analgesia compared to systemic analgesia. There were insufficient numbers to draw conclusions on the effect of epidural analgesia on serious postoperative complications, functional outcomes, or length of hospital stay.

REVIEWER'S CONCLUSIONS

Epidural analgesia may be useful for postoperative pain relief following major lower limb joint replacements. However, the benefits may be limited to the early (four to six hours) postoperative period. An epidural infusion of local anesthetic or local anesthetic-narcotic mixture may be better than epidural narcotic alone. The magnitude of pain relief must be weighed against the frequency of adverse events. The current evidence is insufficient to draw conclusions on the frequency of rare complications from epidural analgesia, postoperative morbidity or mortality, functional outcomes, or length of hospital stay.

Efficacy of ropivacaine compared with ropivacaine plus sufentanil for postoperative analgesia after major knee surgery

This study compared the analgesic efficacy of an epidural infusion of ropivacaine and ropivacaine with sufentanil following major knee surgery. In a double-blind clinical trial, 115 adult patients received either epidural ropivacaine (R group, 2 mg.ml(-1)), or ropivacaine (2 mg.ml(-1)) with sufentanil (RS group, 1 microg.ml(-1)), using a patient-controlled epidural analgesia technique. Pain scores (visual analogue scale, VAS, and the simple descriptive scale, SDS), side-effects, motor block and treatment quality were recorded at 6, 12 and 24 h after the insertion of the epidural catheter. In the RS group, analgesic efficacy was significantly greater than in the R group between 12 and 24 h following insertion of the epidural catheter (VAS: 92.9% vs. 72.9%, p = 0.009). There was no significant difference during the other periods. Pruritus, nausea and vomiting were significantly more frequent in the RS group. Good postoperative analgesia was obtained with an epidural infusion of ropivacaine (2 mg.ml(-1)). When this local anaesthetic was administered with sufentanil, there was an improvement in the analgesic effect but a significant increase in the number of patients who reported adverse effects. The differences were more pronounced 12 h after the beginning of the analgesic schedule. This study failed to demonstrate any worthwhile clinical benefit from the addition of sufentanil.

The efficacy and safety of three concentrations of levobupivacaine administered as a continuous epidural infusion in patients undergoing orthopedic surgery

We evaluated the efficacy and safety of three concentrations of levobupivacaine infused epidurally as analgesia for patients undergoing orthopedic procedures. Patients undergoing elective hip or knee joint replacement were enrolled in the study (n = 105). Sensory blockade was established preoperatively with 10-15 mL of 0.75% levobupivacaine. Patients were then randomized to receive 0.0625%, 0.125%, or 0.25% levobupivacaine as a continuous epidural infusion at 6 mL/h for 24 h. IV morphine patient-controlled analgesia was given as rescue analgesia, and time to first request for analgesia and total dose of morphine consumed were recorded. Sensory blockade, motor blockade, visual analog scale pain score, and cardiovascular variables were also recorded at regular intervals postoperatively. Ninety-one patients were included in the primary intent-to-treat analysis. Total normalized dose of morphine, number of patient-controlled analgesia requests, and overall postoperative visual analog scale pain scores were significantly lower for the 0.25% group compared with the other two groups, and the time to first request for rescue analgesia was longer. There was no significant difference between the 0.125% and 0.25% groups in terms of maximum motor blockade achieved and time to minimal motor blockade. Safety data were equivalent among the three groups. We conclude that levobupivacaine as a continuous epidural infusion provided adequate postoperative analgesia and that the 0.25% concentration provided significantly longer analgesia than 0.125% or 0.0625% levobupivacaine without any significant increase in detectable motor blockade relative to the 0.125% group.

IMPLICATIONS

Postoperative epidural infusion of levobupivacaine can provide safe and effective analgesia for patients having hip or knee joint replacement. Of the three concentrations we infused at a constant rate, 0.25% provided significantly better pain relief.

Continuous femoral blocks improve recovery and outcome of patients undergoing total knee arthroplasty

This study was designed to determine the effects of continuous femoral infusion (CFI) on total knee arthroplasty recovery. A total of 92 patients were distributed in 3 groups: Patients in group 1 received general anesthesia followed by patient-controlled analgesia (PCA) with morphine (n = 33), patients in group 2 received 3-in-1 and sciatic blocks followed by CFI (n = 29), and patients in group 3 received epidural analgesia (n = 30). Blocks reduced postoperative morphine requirement by 74% (vs group 1; P<.05) and 35% (vs group 3; P<.05). Blocks provided better recovery than PCA with morphine or an epidural. The use of CFI was associated with a reduction of postoperative bleeding by 72% (vs group 1; P<.05) and allowed better performance on continuous passive motion. CFI was associated with a 90% decrease in serious complications and a 20% decrease in the length of hospitalization. CFI represents a better alternative than PCA or epidural analgesia for postoperative pain management and immediate rehabilitation after total knee arthroplasty.

Assessment of pain experiences after elective surgery

Pain in the postoperative period has remained a clinical problem in spite of major progress in pain assessment and management. The aim of the present study was to describe in detail the time course of pain experiences of surgical patients (n=200) following elective surgical procedures. Visual analogue scale (VAS, 0-100 mm) was used for pain intensity ratings at 4, 24, 48, and 72 hours after surgery. Interviews were carried out to assess the occurrence of intermittent worst pain episodes during each 24-hour period and to relate such experiences to clinical events. At 4, 24, 48, and 72 hours postoperatively, 39%, 43%, 27%, and 16% of the patients, respectively, experienced moderate or even severe pain (VAS > or =40 mm) at rest. During the first 24 hours after surgery, 88% of the patients had experienced moderate or severe pain at some time (VAS > or =40 mm). Corresponding figures for the following 24 hour periods were 81% and 72%, respectively. Spontaneous pain breakthrough and movement/mobilization were identified as reasons for the worst pain episodes during the first 72-hour period after surgery. The probability of pain intensity of VAS >40 mm was calculated from individual regression functions. The probability was found to be much higher for patients receiving parenteral analgesics than for patients receiving prolonged epidural analgesia. Despite major improvements in pain assessment and management, postoperative patients often experience moderate to severe pain, and worst pain episodes occur even in the late postoperative phase. The present study emphasizes that in the clinical routine management of pain, further quality assurance efforts are necessary.

Extended "three-in-one" block after total knee arthroplasty: continuous versus patient-controlled techniques

This prospective, randomized, double-blinded study assessed the efficacy of patient-controlled analgesia (PCA) techniques for extended "3-in-1" block after total knee arthroplasty. A total of 45 patients were divided into three groups of 15. Over 48 h, all patients received 0.125% bupivacaine with 1 microg/mL clonidine via a femoral nerve sheath catheter in the following manner: as a continuous infusion at 10 mL/h in Group 1; as a continuous infusion at 5 mL/h plus PCA boluses (2.5 mL/30 min) in Group 2; or as PCA boluses only (10 mL/60 min) in Group 3. Pain scores, sensory block, supplemental analgesia, bupivacaine consumption, side effects, and satisfaction scores were recorded. Pain scores and supplemental analgesia were comparable in the three groups. Bupivacaine consumption was significantly less in Groups 2 and 3 than in Group 1 (P < 0.01), and in Group 3 than in Group 2 (P < 0.01). Side effects and satisfaction were comparable in the three groups. We conclude that extended "3-in-1" block provides efficient pain relief after total knee arthroplasty and that, compared with a continuous infusion, PCA techniques reduce the local anesthetic consumption without compromise in patient satisfaction or visual analog scale scores. Of the two PCA techniques tested, PCA boluses (10-mL lockout; time, 60 min) of 0.125% bupivacaine with 1 microg/mL clonidine was associated with the smallest local anesthetic consumption, and is, therefore, the recommended extended "3-in-1" block technique.

IMPLICATIONS

We demonstrated that, after total knee arthroplasty, an extended "3-in-1" block consisting of patient-controlled analgesia boluses (10 mL/60 min) of 0.125% bupivacaine with 1 microg/mL clonidine provides efficient postoperative analgesia and significantly minimizes local anesthetic consumption.

Effects of intravenous patient-controlled analgesia with morphine, continuous epidural analgesia, and continuous three-in-one block on postoperative pain and knee rehabilitation after unilateral total knee arthroplasty

In this study, we assessed the influence of three analgesic techniques on postoperative knee rehabilitation after total knee arthroplasty (TKA). Forty-five patients scheduled for elective TKA under general anesthesia were randomly divided into three groups. Postoperative analgesia was provided with i.v. patient-controlled analgesia (PCA) with morphine in Group A, continuous 3-in-1 block in Group B, and epidural analgesia in Group C. Immediately after surgery, the three groups started identical physical therapy regimens. Pain scores, supplemental analgesia, side effects, degree of maximal knee flexion, day of first walk, and duration of hospital stay were recorded. Patients in Groups B and C reported significantly lower pain scores than those in Group A. Supplemental analgesia was comparable in the three groups. Compared with Groups A and C, a significantly lower incidence of side effects was noted in Group B. Significantly better knee flexion (until 6 wk after surgery), faster ambulation, and shorter hospital stay were noted in Groups B and C. However, these benefits did not affect outcome at 3 mo. We conclude that, after TKA, continuous 3-in-1 block and epidural analgesia provide better pain relief and faster knee rehabilitation than i.v. PCA with morphine. Because it induces fewer side effects, continuous 3-in-1 block should be considered the technique of choice.

IMPLICATIONS

In this study, we determined that, after total knee arthroplasty, loco-regional analgesic techniques (epidural analgesia or continuous 3-in-1 block) provide better pain relief and faster postoperative knee rehabilitation than i.v. patient-controlled analgesia with morphine. Because it causes fewer side effects than epidural analgesia, continuous 3-in-1 block is the technique of choice.

Comparison of intrathecal morphine and continuous femoral 3-in-1 block for pain after major knee surgery under spinal anaesthesia

Major knee surgery is associated with moderate or severe post-operative pain. Intrathecal morphine and continuous femoral 3-in-1 block were compared prospectively in 40 patients for pain after major knee surgery under spinal anaesthesia, with 4 mL isobaric 0.5% bupivacaine. In a random order, 20 patients received preservative free morphine 0.3 mg mixed with spinal bupivacaine. In 20 patients, following spinal anaesthesia with only bupivacaine, femoral 3-in-1 block was performed post-operatively with 0.5% bupivacaine 2 mg kg-1. The block was continued via a catheter with 0.25% bupivacaine 0.1 mL h-1 kg-1 until the next morning (24 h after induction of spinal anaesthesia). Intramuscular oxycodone was given as a rescue analgesic in all patients. Two patients from the femoral group were excluded due to technical failure. Three patients in the morphine group and one patient in the femoral group did not need any additional oxycodone. In the morphine group on average 2.8 (range 0-7) and in the femoral group 3.2 (0-5) additional doses of oxycodone were needed during the 24 h observation period. The mean pain scores were significantly lower in the morphine group at 9 and 12 h into the 24-h trial. Itching was seen only in the morphine group (40% of the patients). Other side effects were similar in the two groups. All patients were satisfied with their pain therapy. Both intrathecal morphine and femoral 3-in-1 block alone were insufficient for the treatment of severe pain after major knee surgery.

Epidural infusion of bupivacaine 0.0625% plus fentanyl 3.3 micrograms/ml provides better postoperative analgesia than patient-controlled analgesia with intravenous morphine after gynaecological laparotomy

One hundred and twenty women undergoing gynaecological abdominal operations were randomized to receive either epidural bupivacaine 0.0625% + fentanyl 3.3 micrograms/ml infusion (Group EPI, n = 57), or patient-controlled intravenous morphine analgesia (Group PCA, n = 54) for postoperative pain relief. The groups were comparable in demographic data, types and duration of operation. Group EPI achieved significantly lower verbal rating scale of pain (VRS) at rest at 0, 4, 12, 16, 20, 28 and 40th postoperative hours. The VRS during cough were also significantly lower in Group EPI at 0, 4, 8, 12, 28 and 36th postoperative hours. None of the patients had respiratory depression or hypotension. Nausea/vomiting occurred in 52.6%/33.3% of patients in Group EPI and 52.7%/37.0% in Group PCA. Most patients (84.2% in Group EPI and 72.2% in Group PCA) rated their pain management as "good". We conclude that epidural infusion of bupivacaine 0.0625% and fentanyl 3.3 micrograms/ml provide better analgesia than patient-controlled intravenous morphine after gynaecological laparotomy.

Peroneal nerve palsy after total knee arthroplasty. Assessment of predisposing and prognostic factors

Thirty-two postoperative peroneal-nerve palsies in thirty patients were documented in a retrospective review of 10,361 consecutive total knee arthroplasties performed at one institution from 1979 through 1992. The mean age of the thirty patients was sixty-five years (range, twenty-eight to seventy-eight years). Four of these patients had had a previous proximal tibial osteotomy and five had had a previous lumbar laminectomy. Ten knees (ten patients) had preoperative valgus alignment of 12 degrees or more. A control group of 100 patients who had had total knee arthroplasty during the same period was computer-matched to the patients by age, sex, and operating surgeon. Comparison of this control group with the thirty patients showed that epidural anesthesia for postoperative control of pain (p < 0.03), previous laminectomy (p < 0.04), and preoperative valgus deformity (p < 0.0001) were significantly associated with peroneal nerve palsy. The relative risk for patients who had had a previous proximal tibial osteotomy was doubled, but this was not significant (p < 0.4). To determine risk factors associated with anesthesia better, a subgroup of 4388 total knee arthroplasties performed during a five-year period (1988 through 1992) was also studied. In this sample, twenty-five peroneal-nerve palsies were documented. Eighteen occurred after epidural anesthesia (p < 0.03); five, after general anesthesia; and two, after spinal anesthesia. An important finding of this study is the high frequency of delayed presentation of peroneal nerve palsy. We believe that epidural anesthesia for postoperative control of pain leads to decreased proprioception and sensation postoperatively. It is postulated that positioning of the limb in this unprotected state may be a factor in the late development of palsy. The concept of the so-called double-crush phenomenon may partially explain the palsy seen in the patients who had had a lumbar laminectomy and asymptomatic peripheral neuropathy.

Continuous epidural infusion of ropivacaine for the prevention of postoperative pain after major orthopaedic surgery: a dose-finding study

PURPOSE

A dose-finding study to investigate the use of epidural infusions of ropivacaine for postoperative analgesia following orthopaedic surgery.

METHODS

This was a randomized, double-blind study. Surgery was performed using a combination of a lumbar epidural block utilizing ropivacaine 0.5% and a standardized general anaesthetic. Postoperatively, an epidural infusion of the study solution (saline, ropivacaine 0.1%, 0.2% or 0.3%) was started at the rate of 10 ml.hr-1 and continued for 21 hr after arrival in the PACU. Analgesia was supplemented with PCA morphine (dose = 1.0 mg, lock-out = 5 min).

RESULTS

Forty-four patients completed the study. The ropivacaine 0.1%, 0.2%, 0.3% groups required less morphine over the 21 hr than the saline group (P < 0.01). The VAS pain scores were also lower in the three ropivacaine groups (P < 0.001). The ropivacaine groups maintained sensory anaesthesia to pinprick when compared with saline (P < 0.05). The motor block in the 0.3% group was significantly higher than the saline group at all times (P < 0.05), and higher than the 0.1% group at eight hours (P < 0.01), while the 0.2% group had higher Bromage scores than saline at 4 and 21 hr (P < 0.05).

CONCLUSIONS

The use of continuous epidural infusions of ropivacaine 0.1%, 0.2% and 0.3% at 10 ml.hr-1 improved postoperative pain relief and decreased PCA morphine requirements in patients undergoing major orthopaedic surgery. The 0.1% and 0.2% concentrations produced similar sensory anaesthesia with less motor blockade than the 0.3% concentration.

Postoperative Epidural Pain Management

Postoperative pain can be effectively managed with epidurally administered opioids or local anesthetics. This article briefly reviews spinal cord anatomy. Pharmacokinetic and pharmacodynamic properties of epidurally administered opioids and local anesthetics are outlined. The pharmacist's participation in a pharmaceutical care plan for the acute postoperative pain patient is also discussed.

Post-operative delirium: predictors and prognosis in elderly orthopedic patients

OBJECTIVE

To compare the effect of post-operative analgesia using epidural versus intravenous infusions on the incidence of delirium after bilateral knee replacement surgery in elderly patients. Additional risk factors and impact on post-operative recovery were also assessed.

DESIGN

Prospective randomized controlled trial.

SETTING

Urban referral hospital specializing in elective orthopedic surgery.

PATIENTS

60 consecutive patients undergoing bilateral knee replacement surgery with epidural anesthesia were approached; 51 patients were eligible and consented. The mean age was 68, 55% were women, and there was a high prevalence of comorbid medical disease. No patient was demented pre-operatively.

INTERVENTION

Random allocation to either continuous epidural infusion of bupivacaine and fentanyl or continuous intravenous infusion of fentanyl. Infusions were initiated at the first complaint of pain and continued through the 36- to 48-hour stay in the recovery room.

MAIN OUTCOME MEASURE

Acute post-operative delirium defined using an algorithm based on DSM III criteria.

RESULTS

The overall incidence of acute delirium was 41%, with no difference between types of post-operative analgesia. Predictors of delirium were age, gender, and pre-operative alcohol use. All cases resolved within 1 week, and length of stay and achievement of physical therapy goals were the same for delirious and non-delirious patients.

CONCLUSIONS

There is a high incidence of post-operative delirium in elderly non-demented patients following bilateral knee replacement, regardless of whether post-operative analgesia is administered by the epidural or intravenous route.

Comparison of epidural and patient-controlled intravenous morphine following joint replacement surgery

The authors conducted a randomized, prospective study comparing epidural morphine with patient-controlled intravenous (iv) morphine in 30 patients recovering from total hip or total knee arthroplasty. Six, 18, and 24 hr postoperatively, patients used a 10 cm visual-analogue scale to indicate both their current degree of discomfort and the maximum discomfort they had experienced since the previous evaluation. Pain at the time of evaluation did not differ between patients receiving epidural (2.6 +/- 0.4 cm, mean +/- SEM) and patient-controlled iv morphine (3.4 +/- 0.3 cm). However, patients who received epidural morphine recalled less pain during the period preceding evaluation (4.2 +/- 0.5 cm) than did those receiving patient-controlled analgesia (5.5 +/- 0.4 cm, P less than 0.05). Patients receiving epidural morphine were more likely to require treatment for pruritus (4 of 15) than patients who received patient-controlled iv morphine (none of 15, P less than 0.05). Minimum respiratory rates were lower in patients receiving epidural morphine (15.0 +/- 0.3) than in those receiving patient-controlled analgesia (16.5 +/- 0.4, P less than 0.05), but no patients required treatment for respiratory depression. The authors conclude that epidural morphine may provide more consistent analgesia following joint replacement surgery than patient-controlled morphine; however, there is a higher incidence of side-effects with the epidural technique.

Comparison of extradural and intravenous diamorphine as a supplement to extradural bupivacaine

The influence of route of administration (extradural as compared with intravenous) of diamorphine 0.5 mg/hour as a supplement to extradural bupivacaine (0.125% at 15 ml/hour) was investigated in two groups of 20 patients who underwent major abdominal gynaecological surgery. Significantly more patients in the intravenous group withdrew because of inadequate analgesia (p less than 0.05). Those in the extradural group were significantly more drowsy throughout the study (p less than 0.01), but no major side effects were encountered.

Management of postoperative pain: review of current techniques and methods

Pain is a common problem in the early postoperative period. Techniques that provide perioperative analgesia to alleviate pain may have a significant effect on postoperative events, such as earlier ambulation and earlier dismissal from the hospital with use of epidural analgesia than with systemic analgesia. Spinal opioids, which can be administered epidurally or intrathecally, provide analgesia that is superior to that achieved with systemically administered narcotics. For procedures on the upper extremities, selective analgesia can be achieved with use of various types of neural blockade--for example, brachial plexus blockade, interscalene blockade, and axillary plexus blockade. Intercostal nerve block, a valuable but underutilized procedure appropriate for unilateral upper abdominal or flank operations or for thoracotomy, has been shown to reduce postoperative narcotic requirements and pulmonary complications. A patient-controlled analgesia device, consisting of an electronically controlled infusion pump with a timing device that can be triggered by the patient for intravenous administration of a narcotic when pain is experienced, avoids the vast fluctuations in analgesia that accompany parenteral administration of drugs. In most patients, postoperative pain can be prevented or diminished, and clinicians should be aware of the available techniques for achieving this goal.

[Continuous block of the femoral nerve after surgery of the knee: pharmacokinetics of bupivacaine]

Ten ASA Class 1 and 2 patients, aged from 16 to 56 years (mean +/- SD: 37 +/- 17 years), scheduled for knee surgery were studied. At the end of the surgical procedure under general anesthesia, an epidural catheter was inserted in the femoral space. After X-ray opacification, a bolus of 2.5 mg.kg-1 of 0.5% bupivacaine with epinephrine was injected. A maintenance infusion was performed during 48 hours with 0.25 mg.kg-1.h-1 of 0.125% bupivacaine without epinephrine. Pain score recorded with an visual analogue scale was 5.0 +/- 1.9 before femoral block. Pain score decreased significantly from 6 to 48 hours. Plasma bupivacaine levels at 24, 36 and 48 hours were significantly higher than the levels obtained at 30 min, 1, 6 and 12 hours. Mean plasma bupivacaine level at steady state was 1.78 +/- 0.59 micrograms.ml-1. Clearance of bupivacaine was 2.59 +/- 0.91 ml.min-1.kg-1. No neurologic complications have been recorded.

Less pain with epidural morphine after knee arthroplasty

Twenty-two patients were randomly allocated to systemic opioids or epidural morphine the first 10 days after total knee arthroplasty. Pain was recorded daily in a visual analogue scale, and knee motion was measured on Day 10. Pain was lower in the epidural group, with no difference in knee flexion or range of motion.