Shot Block Research Articles

A strategic framework for optimal decisions in football 1-vs-1 shot-taking situations: an integrated approach of machine learning, theory-based modeling, and game theory

Complex interactions between two opposing agents frequently occur in domains of machine learning, game theory, and other application domains. Quantitatively analyzing the strategies involved can provide an objective basis for decision-making. One such critical scenario is shot-taking in football, where decisions, such as whether the attacker should shoot or pass the ball and whether the defender should attempt to block the shot, play a crucial role in the outcome of the game. However, there are currently no effective data-driven and/or theory-based approaches to analyzing such situations. To address this issue, we proposed a novel Shooting Payoff Computation (SPC) framework to analyze such scenarios based on game theory, where we estimate the expected payoff with machine learning (ML) models, and additional features for ML models were extracted with a theory-based shot block model. Conventionally, successes or failures (1 or 0) are used as payoffs, while a success shot (goal) is extremely rare in football. Therefore, we proposed the Expected Probability of Shot On Target (xSOT) metric to evaluate players’ actions even if the shot results in no goal; this allows for effective differentiation and comparison between different shots and even enables counterfactual shot situation analysis. In our experiments, we have validated the SPC framework by comparing it with baseline and ablated models. Furthermore, we have observed a high correlation between the xSOT and existing metrics. This alignment of information suggests that xSOT provides valuable insights. Lastly, as an illustration, we studied optimal strategies in the World Cup 2022 and analyzed a shot situation in EURO 2020.

Continuous Vs Single Shot Block After ACL

Continuous Vs Single Shot Block After ACL

Continuous adductor canal blockade facilitates increased home discharge and decreased opioid consumption after total knee arthroplasty

BackgroundThere is a growing interest in avoiding discharging patients to rehab to maximize outcome and minimize complications after total knee arthroplasty (TKA). In addition, use of postoperative pain pathways that minimize opioid use is critical amidst the current opioid epidemic. However, the ideal pain regimen after TKA has yet to be determined. MethodsFrom July 1, 2013 to October 1, 2014 two perioperative pathways were used to address surgical pain. These included either a single shot femoral nerve block plus liposomal bupivacaine pericapsular injection (FNB + LB-PAI) or adductor canal catheter plus posterior capsule single shot block (ACC + iPACK), each with an oral analgesic protocol. Little modification occurred with regard to surgical technique, postoperative medications, or postoperative physical therapy (PT). ResultsOverall, 264 unilateral, primary TKA patients (146 FNB + LB-PAI, 118 ACC + iPACK) were included. ACC + iPACK patients had a shorter median length of stay (LOS, 2.0 vs 3.0, p < 0.001), more discharges home (79.7% vs 67.8%, p = 0.002), and less median opioid consumption (IV morphine equivalents, IVME, 20.0 vs 44.1, p < 0.001) than the FNB + LB-PAI group. In multivariable analysis, use of ACC + iPACK remained independently associated with shorter LOS, increased discharge home, and less IVME consumed when controlling for confounding variables. ACC + iPACK patients also had fewer opioid related adverse events (0.8 vs 5.5, p = 0.045) and a lower rate of MUA (0.8% vs 6.2%, p = 0.026). ConclusionsWe recommend ACC + iPACK with a multimodal oral analgesic protocol as the primary postoperative analgesia in enhanced recovery TKA protocols. This resulted in an easier recovery with fewer complications. Level of evidenceLevel III.

Peripheral nerve blocks for hip fractures.

Various nerve blocks with local anaesthetic agents have been used to reduce pain after hip fracture and subsequent surgery. This review was published originally in 1999 and was updated in 2001, 2002, 2009 and 2017. This review focuses on the use of peripheral nerves blocks as preoperative analgesia, as postoperative analgesia or as a supplement to general anaesthesia for hip fracture surgery. We undertook the update to look for new studies and to update the methods to reflect Cochrane standards. For the updated review, we searched the following databases: the Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 8), MEDLINE (Ovid SP, 1966 to August week 1 2016), Embase (Ovid SP, 1988 to 2016 August week 1) and the Cumulative Index to Nursing and Allied Health Literature (CINAHL) (EBSCO, 1982 to August week 1 2016), as well as trial registers and reference lists of relevant articles. We included randomized controlled trials (RCTs) involving use of nerve blocks as part of the care provided for adults aged 16 years and older with hip fracture. Two review authors independently assessed new trials for inclusion, determined trial quality using the Cochrane tool and extracted data. When appropriate, we pooled results of outcome measures. We rated the quality of evidence according to the GRADE Working Group approach. We included 31 trials (1760 participants; 897 randomized to peripheral nerve blocks and 863 to no regional blockade). Results of eight trials with 373 participants show that peripheral nerve blocks reduced pain on movement within 30 minutes of block placement (standardized mean difference (SMD) -1.41, 95% confidence interval (CI) -2.14 to -0.67; equivalent to -3.4 on a scale from 0 to 10; I2 = 90%; high quality of evidence). Effect size was proportionate to the concentration of local anaesthetic used (P < 0.00001). Based on seven trials with 676 participants, we did not find a difference in the risk of acute confusional state (risk ratio (RR) 0.69, 95% CI 0.38 to 1.27; I2 = 48%; very low quality of evidence). Three trials with 131 participants reported decreased risk for pneumonia (RR 0.41, 95% CI 0.19 to 0.89; I2 = 3%; number needed to treat for an additional beneficial outcome (NNTB) 7, 95% CI 5 to 72; moderate quality of evidence). We did not find a difference in risk of myocardial ischaemia or death within six months, but the number of participants included was well below the optimal information size for these two outcomes. Two trials with 155 participants reported that peripheral nerve blocks also reduced time to first mobilization after surgery (mean difference -11.25 hours, 95% CI -14.34 to -8.15 hours; I2 = 52%; moderate quality of evidence). One trial with 75 participants indicated that the cost of analgesic drugs was lower when they were given as a single shot block (SMD -3.48, 95% CI -4.23 to -2.74; moderate quality of evidence). High-quality evidence shows that regional blockade reduces pain on movement within 30 minutes after block placement. Moderate-quality evidence shows reduced risk for pneumonia, decreased time to first mobilization and cost reduction of the analgesic regimen (single shot blocks).

Anterior Quadratus Lumborum Block Versus Transversus Abdominis Plane Block with Liposomal Bupivacaine: A Case Report

A more posterior approach for abdominal wall blocks was described by Dr. Blanco as Quadratus Lumborum (QL) block. We performed the first reported transmuscular QL block using liposomal bupivacaine. We are describing the technique we used as well as other approaches used for QL block. This case report showed that QL block using a single dose of Liposomal Bupivacaine provided a sensory level and analgesia for 2 days. Our limited experience shows that this new type of block can prolong the analgesia along mid and lower thoracic dermatomes. to quadratus lumborum (QL) muscle has been sought for to potentially provide the patients with more visceral blockade and thus better analgesia [2,3]. Moreover, the effective period of this block can be prolonged by using liposomal bupivacaine [4]. This is the first report demonstrating injection of liposomal bupivacaine for a QL block. Description of the Case Institutional Review board of Cleveland Clinic waived written consent since there was no patient identifying information. The patient was a 32-year-old male with body mass index of 21.07 kg/m2 who was scheduled for a subtotal colectomy in the setting of ulcerative colitis. The surgery was scheduled to be performed through a midline incision extending from above the umbilicus to pubic symphysis. Preoperatively, our acute pain management service was consulted. The patient was initially offered an epidural catheter, which he refused due to previous ineffective analgesia. Thereafter, TAP and QL blocks were offered to the patient and the risks and benefits were explained. It was also explained to the patient that QL blocks and Liposomal bupivacaine use are not investigated thoroughly yet. The patient expressed understanding and agreed to proceed with the proposed set of blocks. The patient subsequently received a left QL (trans-muscular approach, type 3) and a right TAP single shot block for postoperative pain control to allow the right side to serve as a “control”. The blocks were performed in the induction room, with routine monitoring and midazolam (2 mg IV) sedation. The patient was initially placed in right lateral decubitus position. After sterile prepping and draping, a low frequency (2-5 MHz) curved array ultrasound transducer (Mindray, Nanshan, Shenzhen, China) covered in sterile plastic sheath was placed in the anterior axillary line between the subcostal margin and the

Impact of preoperative continuous femoral blockades on morphine consumption and morphine side effects in hip-fracture patients: A randomized, placebo-controlled study

BackgroundUpon arrival at the emergency department, hip-fracture pain relief is usually carried out via systemic opioids. Continuous nerve blocks are efficient in the postoperative period, but have not been evaluated preoperatively. This study compared the reduction in morphine consumption and related side effects of a continuous femoral block with a single shot block in hip-fracture patients. MethodsHip-fracture patients admitted to the emergency department received a femoral nerve catheter, with a single lidocaine injection. They were then randomized to ropivacaine (group R) or saline continuous infusion (placebo, group P) in a double-blind manner. Morphine consumption and side effects were prospectively collected until the 24th postoperative hour. ResultsSixty patients were included and 55 analyzed. There were no significant differences between the 2 groups regarding fracture types, delay before surgery (median [Q1–Q3]: 21.3 [14.5–29.4] versus 20.8 [15.7–36.2] hours for groups R and P, respectively; P=0.87) and catheter duration (47.5 [39.8–52.4] versus 42.5 [32.1–50.5] hours, P=0.29). Total morphine consumption was not significantly decreased in group R (5 [0–14] versus 8 [4.5–11] mg, P=0.3) and pain scores were similar (mean±SD; VAS 29±15/100 versus 33±13, P=0.3). We observed a significant reduction in morphine adverse effects (31% versus 69% for groups R and P, respectively; P<0.01), mainly nausea (31% versus 59%, P=0.03). One morphine side effect could be avoided for every 5 patients treated. ConclusionPreoperative continuous femoral blockades using ropivacaine reduce morphine side effects (mainly nausea) in hip-fracture patients without reducing morphine consumption.

Adductor Canal Blockade Following Total Knee Arthroplasty—Continuous or Single Shot Technique? Role in Postoperative Analgesia, Ambulation Ability and Early Functional Recovery: A Randomized Controlled Trial

Total knee arthroplasty (TKA) can be associated with severe pain in early postoperative period. Adductor canal block may provide optimal analgesia following TKA. However, ideal regimen for administration whether continuous or single shot is yet undefined. We prospectively randomized 90 patients in continuous and single shot adductor canal blockade groups. Postoperative VAS (visual analog scale for pain) score was significantly better at all times in continuous than single shot technique (P<0.001). However, ambulation ability (Timed Up & Go, 10m walk, 30s chair) and early functional recovery (active SLR, ambulation with walker, staircase competency, ambulation distance and maximal flexion at discharge) showed no statistical significant difference. Continuous adductor canal blockade was superior to single shot block in terms of pain control but was similar for early functional recovery. Level of evidenceLevel III, therapeutic study.

0.5% levobupivacaine versus 0.5% ropivacaine: Are they different in ultrasound-guided sciatic block?

Context and Aims:Little is known about onset and duration of sciatic block after 0.5% levobupivacaine (Levo) versus 0.5% ropivacaine (Ropi) for ultrasound-guided technique. We assessed these parameters in the ultrasound-guided block, to know for the practice.Setting and Design:A comparative randomized double-blind study was conducted in the University Hospital.Materials and Methods:Were included 35 adults of ASA I-II, scheduled for foot surgery, presenting clear imaging of their sciatic nerve at mid-thigh. A volume of 20 mL of either 0.5% Levo or 0.5% Ropi were injected around the sciatic nerve at mid-thigh using ultrasound guidance (out of the plane) followed by placement of a catheter to use, if necessary, for perioperative analgesia. A femoral single shot block was systematically performed to block the saphenous nerve. The onset times until complete foot block (primary outcome) and the sensory and motor block duration (secondary outcome) were assessed using Wilcoxon test. Values were expressed as medians (1st-3rd quartile).Results:Except for two delayed sciatic blocks in each group, the onset time otherwise was 35 min (20-60) in Ropi versus 40 min (30-60) in Levo, P = 0.5. Sensory block lasted longer in Levo, 17 h (14-27) compared with 15 h (10-17) in Ropi, P = 0.04. No significant between-group difference was found with motor block durations, 15 h (12-18) in Levo and 15 h (12-16) in Ropi, P = 0.3.Conclusion:No difference of onset times was found in ultrasound-guided sciatic block whether using Levo or Ropi. Levo induced a longer-lasting sensory block.

Incidence and severity of complications due to femoral nerve blocks performed for knee surgery

Background: While single shot femoral nerve blocks and indwelling femoral nerve catheters provide significant peri-operative analgesia, there are small but serious risks of neurovascular complications. We aimed to determine the incidence and characterise the nature of neural complications arising from femoral nerve blocks performed for knee surgery.Methods: One thousand eight hundred and two patients receiving a femoral nerve block for knee surgery during the study period were screened. Patients with possible neurological symptoms were evaluated with a detailed physical examination and self-report questionnaires. Also measures of depression, anxiety and tension/stress were collected.Results: In the patients screened, an incidence of 1.94% was found. Of the 24 patients available for testing, 4 had bilateral symptoms following bilateral nerve blocks. All had sensory abnormalities in the distribution of the femoral nerve. The incidence was significantly higher in females (females=2.5%, males=0.83% p=0.01) and in patients receiving a single shot block (single shot=2.66%, femoral catheter=0.93, p=0.01).Conclusions: The incidence of neurological complication after FNB was higher in this series than typically reported and the symptoms significantly influenced the quality of life in the affected cases. The decision to include a femoral nerve block in the peri-operative analgesic regimen should be made on an individual basis considering the risks and benefits. Level of evidenceTherapeutic level IV.

Role of ultrasound-guided continuous brachial plexus block in the management of neonatal ischemia in upper limb

Neonatal upper limb ischemia due to accidental arterial damage remains a major concern, which can lead to devastating complications if untreated. The primary objective of this case report is to emphasize the role of continuous infraclavicular brachial plexus block, the issues related with block performance in an ischemic hand, and the importance of ultrasound guidance in this particular case scenario. A 1.1 kg infant suffered from distal forearm ischemia due to accidental arterial damage, which was treated with brachial plexus block. An ultrasound-guided single shot block with 0.5 mL/kg of 0.25% bupivacaine was followed by ultrasound-guided catheter placement in the target area. A continuous infusion of 0.03% of bupivacaine at the rate of 0.5 mL/kg/hr (approx. 0.15 mg/kg/h of bupivacaine) was administered for 36 h. This treatment resulted in reversal of ischemia. Permanent ischemic damage was eventually confined to the tips of 4 fingers. We conclude that ultrasound-guided continuous infraclavicular block has a therapeutic role to play in the treatment of hand ischemia due to arterial damage and subsequent arterial spasm in neonates with added benefits.

Inappropriate Conclusion from Meta-analysis of Randomized Controlled Trials

We thank Drs. Barrington, Olive, and Kluger for their interest in our recent meta-analysis of femoral nerve block for total knee arthroplasty and for the opportunity to respond to their concerns.1The concern raised is that the key message in the highlighted box on the first page of the article, “that these studies did not demonstrate further improvement with continuous compared with single-shot femoral nerve block alone,” was unsupported by the data.Of the 23 randomized controlled trials that were included in our meta-analysis, only 2 trials (with a total of 69 patients) directly compared single shot femoral nerve block to continuous femoral nerve block, the trials by Hirst et al. and Salinas et al .2,3The trial by Salinas et al. located the nerve with a nerve stimulator and used 30 ml ropivacaine, 0.375%, with epinephrine for the single shot femoral nerve block, and the continuous femoral nerve block group also received a continuous infusion of ropivacaine, 0.2%, at 10 ml/h. The trial by Hirst et al. also located the nerve using a nerve stimulator but used 20 ml bupivacaine, 0.5%, with epinephrine for the single shot block, and the continuous nerve block group received an infusion of bupivacaine, 0.125%, at 6 ml/h. The trial by Salinas et al. showed that a continuous femoral nerve block (in comparison with a single shot femoral nerve block alone) resulted in lower pain scores (during the first and second postoperative day and during physical therapy) and opioid consumption was also reduced; by contrast, the study by Hirst et al. found that there were no differences in pain scores or opioid consumption. We disagree with Barrington et al. that the trial by Hirst et al. was not clinically appropriate and the results do apply to current practice. Thus, the direct evidence is equivocal, with conflicting evidence for a continuous femoral nerve block.In addition to the direct evidence, our Bayesian meta-analysis combined the indirect results from the 7 trials (with 136 patients) that investigated single shot femoral nerve block and the 13 trials (with 352 patients) that investigated continuous femoral nerve block. These results showed that there was no difference in analgesia outcome for these groups in terms of opioid consumption, pain scores, nausea, range of motion, or length of stay.1The weakness of this approach, that these were not randomized comparisons and subject to the same biases as observational studies, was described in the original paper. We defend our inclusion of trials that used either bupivacaine or ropivacaine for their femoral nerve blocks because one local anesthetic has not been proven superior to the other in terms of block effectiveness.4Thus, the evidence from the indirect comparisons does not support the use of continuous femoral nerve blocks.Overall there is equivocal evidence for a continuous femoral nerve block from the direct evidence and no evidence from the additional indirect comparisons from the Bayesian analysis. Although these indirect comparisons were nonrandomized, the treatment groups were quite similar between studies. Given these results, we feel that the conclusion “that these studies did not demonstrate further improvement with continuous compared with single-shot femoral nerve block alone” was justified.The fact that some of the evidence described in the studies does not come from randomized comparisons is a fair criticism and clearly stated in the article. This is a weakness of the literature, as opposed to the methods used in the meta-analysis. More authors need to study the head-to-head comparisons for single shot versus continuous femoral nerve block for total knee arthroplasty, and this was in fact the final conclusion of our study, as stated in the last sentence. Although the idea of a continuous femoral nerve block makes intuitive sense because it prolongs the duration of the nerve block while patients are still having significant pain, its advantages have not been proven in the literature to date. This message is important for investigators because most of the trials published (11 of the 13 trials of continuous femoral nerve block) ignore the comparison with a single shot nerve block group as if it can be taken for granted that continuous femoral nerve block is the superior approach.*McMaster University, Hamilton, Ontario, Canada. james_paul@sympatico.ca

Surgery under Extreme Conditions in the Aftermath of the 2010 Haiti Earthquake: The Importance of Regional Anesthesia

The 12 January 2010 earthquake that struck Port-au-Prince, Haiti caused >200,000 deaths, thousands of injuries requiring immediate surgical interventions, and 1.5 million internally displaced survivors. The earthquake destroyed or disabled most medical facilities in the city, seriously hampering the ability to deliver immediate life- and limb-saving surgical care. A Project Medishare/University of Miami Miller School of Medicine trauma team deployed to Haiti from Miami within 24 hours of the earthquake. The team began work at a pre-existing tent facility in the United Nations (UN) compound based at the airport, where they encountered 225 critically injured patients. However, non-sterile conditions, no means to administer oxygen, the lack of surgical equipment and supplies, and no anesthetics precluded the immediate delivery of general anesthesia. Despite these limitations, resuscitative care was administered, and during the first 72 hours following the event, some amputations were performed with local anesthesia. Because of these austere conditions, an anesthesiologist, experienced and equipped to administer regional block anesthesia, was dispatched three days later to perform anesthesia for limb amputations, debridements, and wound care using single shot block anesthesia until a better equipped tent facility was established. After four weeks, the relief effort evolved into a 250-bed, multi-specialty trauma/intensive care center staffed with >200 medical, nursing, and administrative staff. Within that timeframe, the facility and its staff completed 1,000 surgeries, including spine and pediatric neurological procedures, without major complications. This experience suggests that when local emergency medical resources are completely destroyed or seriously disabled, a surgical team staffed and equipped to provide regional nerve block anesthesia and acute pain management can be dispatched rapidly to serve as a bridge to more advanced field surgical and intensive care, which takes longer to deploy and set up.

The Sensitivity of Motor Response to Needle Nerve Stimulation During Ultrasound Guided Interscalene Catheter Placement

Neurostimulation during single shot interscalene block has a significant false negative motor response rate. Compared with tangential needle approaches for single shot block, interscalene catheter (ISC) placement commonly involves Tuohy needles inserted longitudinally to the brachial plexus. This study aimed to determine the sensitivity of neurostimulation during ultrasound-guided ISC needle placement, and the feasibility of an ultrasound-guided ISC needle endpoint. One hundred fifty-five consecutive nonstimulating ISCs were placed with the needle tip position confirmed by the sonographic spread of 5 mL dextrose 5%. Catheter advancement was then blind 2 to 3 cm past the needle tip. A 0.8 mA electrical stimulus at 2 Hz was applied throughout. When a satisfactory image was obtained, neurostimulation was ignored and the minimum motor response amplitude noted. If imaging was equivocal, a brief appropriate motor response at 0.8 mA was sought. A sustained response at <0.5 mA was only sought if imaging was suboptimal. Prior to surgery conducted under general anesthesia, 30 mL ropivacaine 0.5% was administered through the ISC. Catheter success was defined as a recovery room numerical rating pain score of </=2 (scale, 0-10). In 57% of patients, a muscle response was not elicited. An ultrasound needle endpoint was used in 92% of ISC placements, of which 96% were successful. Sustained twitches at <0.5 mA were obtained in 12 (8%) patients, 6 (4%) of these deliberately sought because of suboptimal imaging. Catheter success overall was 95%. This study suggests that the false negative motor response rate for longitudinal ISC needle placement is higher than the false negative response rate associated with tangential needle approach interscalene block. An ultrasound guided ISC needle endpoint is a feasible alternative to a neurostimulation endpoint.

Postoperative Analgesia Following Total Knee Arthroplasty: In Response

We appreciate the interest Drs. Lang and Rooney have shown in our work and their implicit endorsement of our conclusion that sciatic blockade is usually necessary after TKA to provide satisfactory conduction analgesia. It is particularly gratifying to see that the nature of discussion has shifted to a plane of how best, rather than whether, to provide continuous peripheral neural blockade for postoperative analgesia. Certainly production pressures are a reality and, sadly, one can expect little patience for pain management practices that delay case flow. Yet it is hard to compare the situation today with that of only 10 years ago. Little dedicated equipment was then available for continuous peripheral neural blockade (CPNB) which usually required a fair amount of effort and jerry-rigging. Today multiple manufacturers market prepackaged CPNB sets, which greatly simplifies matters. Even more important than equipment advances has been the development of greater organizational sophistication. Production pressure becomes much more manageable if one is doing the blocks, as we are, in a properly equipped preoperative area, and if they are in the hands of a dedicated acute interventional pain service (AIPS). If blocks must be done by each individual anesthesiologist in the OR, then in all likelihood they will not be done at all. In our practice, the solution has been formation of a dedicated AIPS team whose sole function is to manage postoperative pain. The assigned attending will spend a week at a time on the service. His duties include both placing the blocks (single and/or continuous) and having primary responsibility for managing the patient’s pain postoperatively. Clearly, the economics and logistics of a dedicated acute pain service will vary for each institution and will require a certain amount of creative adaptation. However, over the years it has become clear to us that 1) a separate dedicated AIPS team with a consistent approach and 2) the continuity of patient care provided by at least weekly assignment of one of the team are critical elements of a successful acute pain program. A situation where each attending does or does not manage postoperative pain as time and inclination allow is a prescription for both problems and failure. While the technique suggested by Drs. Lang and Rooney is interesting and may indeed prove useful, it raises several issues. Use of a single shot block provides time-limited relief and, in fact, will create the very situation postoperatively that we wish to avoid—the inability to distinguish nerve injury from neural blockade. Our method has evolved to the point where we now place the sciatic catheter using saline injectate only. No local anesthetic (LA) is administered via the catheter until, after surgery, the patient has demonstrated intact sciatic function and is complaining of posterior pain. As for use of a catheter passing through or in close proximity to the wound, in our experience, orthopedic surgeons are wary of placing infusion catheters in or about the wound when prosthetic implants are used. Since as many as 1% of implants may suffer from infection, then regardless of whether or not a surgical wound-sited LA catheter predisposes to infection, it will certainly predispose to medicolegal liability (as the catheter will doubtless be blamed for introducing infection). There are several companies currently marketing wound infusion catheters and pumps, and this seems to be a common theme of concern. There are, to our knowledge, no published direct comparisons of CPNB and LA wound infusions, but our impression remains consistent with that of Chelly et al. (1), who found superior analgesia from CPNB versus intraarticular LA infusion. Nevertheless, such an approach to the use of local anesthetic as part of a multimodal analgesic plan may be the most practical in many locales. Bruce Ben-David, MD Clinical Associate Professor of Anesthesiology, University of Pittsburgh Medical Centers-Shadyside Hospital Jacques Chelly, MD, PhD Professor of Anesthesiology and Orthopedic Surgery, University of Pittsburgh Medical Centers, Pittsburgh, PA

Postoperative Analgesia Following Total Knee Arthroplasty: In Response

We appreciate the interest Drs. Lang and Rooney have shown in our work and their implicit endorsement of our conclusion that sciatic blockade is usually necessary after TKA to provide satisfactory conduction analgesia. It is particularly gratifying to see that the nature of discussion has shifted to a plane of how best, rather than whether, to provide continuous peripheral neural blockade for postoperative analgesia. Certainly production pressures are a reality and, sadly, one can expect little patience for pain management practices that delay case flow. Yet it is hard to compare the situation today with that of only 10 years ago. Little dedicated equipment was then available for continuous peripheral neural blockade (CPNB) which usually required a fair amount of effort and jerry-rigging. Today multiple manufacturers market prepackaged CPNB sets, which greatly simplifies matters. Even more important than equipment advances has been the development of greater organizational sophistication. Production pressure becomes much more manageable if one is doing the blocks, as we are, in a properly equipped preoperative area, and if they are in the hands of a dedicated acute interventional pain service (AIPS). If blocks must be done by each individual anesthesiologist in the OR, then in all likelihood they will not be done at all. In our practice, the solution has been formation of a dedicated AIPS team whose sole function is to manage postoperative pain. The assigned attending will spend a week at a time on the service. His duties include both placing the blocks (single and/or continuous) and having primary responsibility for managing the patient’s pain postoperatively. Clearly, the economics and logistics of a dedicated acute pain service will vary for each institution and will require a certain amount of creative adaptation. However, over the years it has become clear to us that 1) a separate dedicated AIPS team with a consistent approach and 2) the continuity of patient care provided by at least weekly assignment of one of the team are critical elements of a successful acute pain program. A situation where each attending does or does not manage postoperative pain as time and inclination allow is a prescription for both problems and failure. While the technique suggested by Drs. Lang and Rooney is interesting and may indeed prove useful, it raises several issues. Use of a single shot block provides time-limited relief and, in fact, will create the very situation postoperatively that we wish to avoid—the inability to distinguish nerve injury from neural blockade. Our method has evolved to the point where we now place the sciatic catheter using saline injectate only. No local anesthetic (LA) is administered via the catheter until, after surgery, the patient has demonstrated intact sciatic function and is complaining of posterior pain. As for use of a catheter passing through or in close proximity to the wound, in our experience, orthopedic surgeons are wary of placing infusion catheters in or about the wound when prosthetic implants are used. Since as many as 1% of implants may suffer from infection, then regardless of whether or not a surgical wound-sited LA catheter predisposes to infection, it will certainly predispose to medicolegal liability (as the catheter will doubtless be blamed for introducing infection). There are several companies currently marketing wound infusion catheters and pumps, and this seems to be a common theme of concern. There are, to our knowledge, no published direct comparisons of CPNB and LA wound infusions, but our impression remains consistent with that of Chelly et al. (1), who found superior analgesia from CPNB versus intraarticular LA infusion. Nevertheless, such an approach to the use of local anesthetic as part of a multimodal analgesic plan may be the most practical in many locales. Bruce Ben-David, MD Clinical Associate Professor of Anesthesiology, University of Pittsburgh Medical Centers-Shadyside Hospital Jacques Chelly, MD, PhD Professor of Anesthesiology and Orthopedic Surgery, University of Pittsburgh Medical Centers, Pittsburgh, PA

Continuous regional analgesia: can we afford not to use it?

Continuous regional analgesia: can we afford not to use it?