Regional Anesthesia and Pain Medicine • Volume 39, Number 3, May-June 2014
We present a case of late systemic toxicity occurring 80 minutes after local infiltration of the knee with 400 mg ropivacaine 0.2%. Permission to report this case was obtained from the patient. A 67-year-old woman presented for a polyethylene tibial insert exchange of a previous total knee arthroplasty under unilateral spinal anesthesia and LIA with ropivacaine 0.2%. Spinal anesthesia was established under routine monitoring with 11 mg bupivacaine in 8% glucose, and the patient was turned on the dependent side for 20 minutes to obtain a preferential right-sided distribution of the spinal anesthesia. Surgery was uneventful and LIA was performed using 100 mL ropivacaine 0.2% with epinephrine 5 μg/mL to infiltrate the dorsal capsule posteromedially and posterolaterally, 50 mL ropivacaine with epinephrine 5 μg/mL to infiltrate the anterior capsule, and 50 mL ropivacaine 0.2% without epinephrine to infiltrate the skin and subcutaneous tissues of the surgical incision, the total dose of ropivacaine being 400 mg. At the conclusion of surgery, the patient was transferred to the recovery unit, where she arrived awake and without pain. From the time of arrival at the recovery unit, her heart rate rose and varied from 100 to 120 beats per minute (bpm), but because it was a sinus rhythm and there were no signs of pain or discomfort, no action was taken at that time. Seventy-five minutes after LIA, she developed atrial fibrillation with a ventricle response up to 150 bpm and the patient became agitated and complained of retrosternal pain. Nitroglycerin spray was administered and metoprolol was titrated intravenously up to 5 mg. Five minutes later, the patient lost consciousness and developed a clonic seizure with convulsions of arms and legs as well as the facial muscles, and the diagnosis of local anesthetic systemic toxicity (LAST) was made. Oxygen was administered, the convulsions were treated with boluses of midazolam 1 mg intravenously, and an infusion with 20% lipid emulsion was started. The convulsions rapidly subsided and the patient breathed spontaneously, arterial hemoglobin oxygen saturation remaining above 90% at all times. The patient regained consciousness in approximately 5 minutes, but she had 2 additional milder episodes of generalized convulsions and decreased consciousness lasting approximately 20 to 30 seconds each during the next 15 minutes. Heart rate decreased to around 100 to 120 bpm with normal blood pressures and peripheral oxygen saturation. The patient was drowsy but no longer complained of retrosternal pain, and she was transferred to the postanesthesia care
unit for observation. During the following hours, she had several short episodes of focal convulsions decreasing in intensity over time, lasting seconds and limited to an arm or a leg, during which she remained conscious and that required no treatment. Sinus rhythm was restored spontaneously, and the last observation of a minor convulsion was made 5.5 hours after the time of LIA. No further events occurred during the evening and night, and the next morning the patient was transferred from the postanesthesia care unit to the orthopedic ward in good condition without sequelae. LAST occurs when the free, unionized concentration of a local anesthetic in plasma exceeds the toxic threshold and toxic concentrations occur in the central nervous system and in the heart. LAST may occur immediately or shortly after the administration of local anesthetic, or after a symptom-free interval. The former situation occurs when systemic absorption of the local anesthetic is unusually high, for example, in case of inadvertent intravenous injection. The latter occurs in situations where systemic absorption may be normal, but the administered dose results in a maximum concentration of local anesthetic exceeding the toxic threshold in that particular patient. Our case is unusual in that cardiac symptoms preceded central nervous system symptoms, and toxic symptoms persisted for 5 hours. Pharmacokinetic data on maximum plasma concentration (Cmax) and time to reach Cmax (Tmax) of high doses of ropivacaine with epinephrine are scarce. In a study using 450 mg ropivacaine with or without epinephrine for combined sciatic and femoral nerve block, Tmax (SD) was 1.67 (0.94) hours for the solution containing epinephrine, and 1.17 (0.30) hours for the epinephrine-free solution.1 In our patient, convulsions started approximately 80 minutes after ropivacaine infiltration; because the infiltration consisted of 300 mg ropivacaine with epinephrine and 100 mg ropivacaine without epinephrine, we believe that a Tmax of 80 minutes (1.33 hours) is in accordance with the aforementioned study. We could not determine ropivacaine plasma concentrations in our patient. Analysis of ropivacaine plasma concentrations is not a simple laboratory measurement, but a complex test requiring a specific setup. For this reason, analysis of individual ropivacaine samples is not routinely available in the Netherlands, and only performed in connection with pharmacokinetic studies where a large number of samples are analyzed in 1 batch. However, we feel that the clinical picture and resolution of symptoms in our patient are evident and sustain the diagnosis of LAST.
© 2014 American Society of Regional Anesthesia and Pain Medicine
Letters to the Editor
Maaike G.E. Fenten, MD Andrea Rohrbach, MD, PhD Ate B. Wymenga, MD, PhD Rudolf Stienstra, MD, PhD Departments of Anesthesiology and Pain Medicine and Orthopaedic Surgery Sint Maartenskliniek Nijmegen, the Netherlands
The authors declare no conflict of interest. REFERENCE 1. Schoenmakers KP, Vree TB, Jack NT, van den Bemt B, van Limbeek J, Stienstra R. Pharmacokinetics of 450 mg ropivacaine with and without epinephrine for combined femoral and sciatic nerve block in lower extremity surgery. A pilot study. Br J Clin Pharmacol. 2013;75:1321–1327.
Regional Anesthesia: Business Class Pain Management? Accepted for publication: February 12, 2014. To the Editor: wish to commend Ironfield et al1 on their excellent article, “Are patients satisfied after peripheral nerve blockade? Results from an international registry of regional anesthesia,” which evaluated the willingness of patients to undergo repeat peripheral nerve blockade for future surgery. This subject is both timely and relevant given the current emphasis on evidenceand outcome-based medicine. Lately, there has been an increase in studies focused on long-term outcomes of regional anesthesia, including stay in hospital, patient mobility after surgery, and impact on cancer recurrence. However, these studies tend to miss the forest for the trees and thereby overlook the immediate goal of regional anesthesia: alleviation of pain and increased comfort during the perioperative period. Some even argue that, if regional anesthesia does not provide any long-term benefits, then why bother administering it? The study by Ironfield et al1 demonstrates that, among patients who received a peripheral nerve block for their surgery, almost 95% of those patients would be willing to have another block for future surgery. Although regional anesthesia is gaining popularity as a modality for controlling pain, general anesthesia and opioidbased analgesia remains the most prevalent means of managing pain during and after surgery. In this regard, many individuals
I
265
Copyright © 2014 American Society of Regional Anesthesia and Pain Medicine. Unauthorized reproduction of this article is prohibited.
Letters to the Editor
who undergo surgery will never experience the benefits of regional anesthesia but will otherwise be satisfied with their care in terms of pain control. Likewise, some surgeons and even some anesthesiologists will not attempt to explain the benefits of regional anesthesia to patients because they have either never needed anesthesia themselves, or see no difference between the benefits of general and regional anesthesia, or think that administering a nerve block is just one more time-consuming step before surgery. In essence, the current perspective regarding regional anesthesia versus traditional anesthesia/analgesia methods resembles the options of business class and economy class when traveling on an airline. One might make the argument that there is no need for separate business and economy classes because there is no actual benefit in terms of arrival time: it takes the same amount of time to reach the destination whether you are relaxing in business class or sitting in a cramped seat near the lavatory. However, anyone who has traveled in both business and economy class will attest to the considerable difference between the 2 options with regard to comfort, service, and overall quality. Moreover, those who have traveled in busi-
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Regional Anesthesia and Pain Medicine • Volume 39, Number 3, May-June 2014
ness class would more than likely choose this option again if they were given the option. Similarly, individuals who receive a nerve block are much more likely to be willing to have another one for future surgery because of their high level of satisfaction with their nerve block the first time. There is a possibility that we are getting distracted from the more important advantages of regional anesthesia by trying to evaluate or quantify its long-term benefits. In trying to prove or justify its long-term benefits, are we in fact asking too much of regional anesthesia? The study by Ironfield et al helps to refocus our attention on the importance of patient satisfaction and wellbeing when deciding on an option for anesthesia. By evaluating patients’ opinions on the immediate benefits of regional anesthesia, rather than assessing some long-term benefit, the article asks the right questions and reminds us that the primary goal of anesthesia is to keep patients free from pain during the perioperative period. In the same way as airlines provide information for passengers regarding the options of business or economy class travel, so too should the anesthesiology community inform the public about their options with respect to pain
management. We want our patients to be as comfortable as possible, and if the option of regional anesthesia is available, should we not promote its effectiveness and advantages over other pain control methods? The study of Ironfield et al does well to remind us that, having had the superior experience offered by a peripheral nerve block, patients will choose this option in the future. What better reason do we need to stop doubting the merits of regional anesthesia?
Ban Chi-Ho Tsui, MD Department of Anesthesiology and Pain Medicine University of Alberta, Edmonton Alberta, Canada
The authors declare no conflict of interest. REFERENCE 1. Ironfield CM, Barrington MJ, Kluger R, Sites B. Are patients satisfied after peripheral nerve blockade? Results from an International Registry of Regional Anesthesia. Reg Anesth Pain Med. 2014;39:48–55.
© 2014 American Society of Regional Anesthesia and Pain Medicine
Copyright © 2014 American Society of Regional Anesthesia and Pain Medicine. Unauthorized reproduction of this article is prohibited.
We present a case of late systemic toxicity occurring 80 minutes after local infiltration of the knee with 400 mg ropivacaine 0.2%. Permission to report this case was obtained from the patient. A 67-year-old woman presented for a polyethylene tibial insert exchange of a previous total knee arthroplasty under unilateral spinal anesthesia and LIA with ropivacaine 0.2%. Spinal anesthesia was established under routine monitoring with 11 mg bupivacaine in 8% glucose, and the patient was turned on the dependent side for 20 minutes to obtain a preferential right-sided distribution of the spinal anesthesia. Surgery was uneventful and LIA was performed using 100 mL ropivacaine 0.2% with epinephrine 5 μg/mL to infiltrate the dorsal capsule posteromedially and posterolaterally, 50 mL ropivacaine with epinephrine 5 μg/mL to infiltrate the anterior capsule, and 50 mL ropivacaine 0.2% without epinephrine to infiltrate the skin and subcutaneous tissues of the surgical incision, the total dose of ropivacaine being 400 mg. At the conclusion of surgery, the patient was transferred to the recovery unit, where she arrived awake and without pain. From the time of arrival at the recovery unit, her heart rate rose and varied from 100 to 120 beats per minute (bpm), but because it was a sinus rhythm and there were no signs of pain or discomfort, no action was taken at that time. Seventy-five minutes after LIA, she developed atrial fibrillation with a ventricle response up to 150 bpm and the patient became agitated and complained of retrosternal pain. Nitroglycerin spray was administered and metoprolol was titrated intravenously up to 5 mg. Five minutes later, the patient lost consciousness and developed a clonic seizure with convulsions of arms and legs as well as the facial muscles, and the diagnosis of local anesthetic systemic toxicity (LAST) was made. Oxygen was administered, the convulsions were treated with boluses of midazolam 1 mg intravenously, and an infusion with 20% lipid emulsion was started. The convulsions rapidly subsided and the patient breathed spontaneously, arterial hemoglobin oxygen saturation remaining above 90% at all times. The patient regained consciousness in approximately 5 minutes, but she had 2 additional milder episodes of generalized convulsions and decreased consciousness lasting approximately 20 to 30 seconds each during the next 15 minutes. Heart rate decreased to around 100 to 120 bpm with normal blood pressures and peripheral oxygen saturation. The patient was drowsy but no longer complained of retrosternal pain, and she was transferred to the postanesthesia care
unit for observation. During the following hours, she had several short episodes of focal convulsions decreasing in intensity over time, lasting seconds and limited to an arm or a leg, during which she remained conscious and that required no treatment. Sinus rhythm was restored spontaneously, and the last observation of a minor convulsion was made 5.5 hours after the time of LIA. No further events occurred during the evening and night, and the next morning the patient was transferred from the postanesthesia care unit to the orthopedic ward in good condition without sequelae. LAST occurs when the free, unionized concentration of a local anesthetic in plasma exceeds the toxic threshold and toxic concentrations occur in the central nervous system and in the heart. LAST may occur immediately or shortly after the administration of local anesthetic, or after a symptom-free interval. The former situation occurs when systemic absorption of the local anesthetic is unusually high, for example, in case of inadvertent intravenous injection. The latter occurs in situations where systemic absorption may be normal, but the administered dose results in a maximum concentration of local anesthetic exceeding the toxic threshold in that particular patient. Our case is unusual in that cardiac symptoms preceded central nervous system symptoms, and toxic symptoms persisted for 5 hours. Pharmacokinetic data on maximum plasma concentration (Cmax) and time to reach Cmax (Tmax) of high doses of ropivacaine with epinephrine are scarce. In a study using 450 mg ropivacaine with or without epinephrine for combined sciatic and femoral nerve block, Tmax (SD) was 1.67 (0.94) hours for the solution containing epinephrine, and 1.17 (0.30) hours for the epinephrine-free solution.1 In our patient, convulsions started approximately 80 minutes after ropivacaine infiltration; because the infiltration consisted of 300 mg ropivacaine with epinephrine and 100 mg ropivacaine without epinephrine, we believe that a Tmax of 80 minutes (1.33 hours) is in accordance with the aforementioned study. We could not determine ropivacaine plasma concentrations in our patient. Analysis of ropivacaine plasma concentrations is not a simple laboratory measurement, but a complex test requiring a specific setup. For this reason, analysis of individual ropivacaine samples is not routinely available in the Netherlands, and only performed in connection with pharmacokinetic studies where a large number of samples are analyzed in 1 batch. However, we feel that the clinical picture and resolution of symptoms in our patient are evident and sustain the diagnosis of LAST.
© 2014 American Society of Regional Anesthesia and Pain Medicine
Letters to the Editor
Maaike G.E. Fenten, MD Andrea Rohrbach, MD, PhD Ate B. Wymenga, MD, PhD Rudolf Stienstra, MD, PhD Departments of Anesthesiology and Pain Medicine and Orthopaedic Surgery Sint Maartenskliniek Nijmegen, the Netherlands
The authors declare no conflict of interest. REFERENCE 1. Schoenmakers KP, Vree TB, Jack NT, van den Bemt B, van Limbeek J, Stienstra R. Pharmacokinetics of 450 mg ropivacaine with and without epinephrine for combined femoral and sciatic nerve block in lower extremity surgery. A pilot study. Br J Clin Pharmacol. 2013;75:1321–1327.
Regional Anesthesia: Business Class Pain Management? Accepted for publication: February 12, 2014. To the Editor: wish to commend Ironfield et al1 on their excellent article, “Are patients satisfied after peripheral nerve blockade? Results from an international registry of regional anesthesia,” which evaluated the willingness of patients to undergo repeat peripheral nerve blockade for future surgery. This subject is both timely and relevant given the current emphasis on evidenceand outcome-based medicine. Lately, there has been an increase in studies focused on long-term outcomes of regional anesthesia, including stay in hospital, patient mobility after surgery, and impact on cancer recurrence. However, these studies tend to miss the forest for the trees and thereby overlook the immediate goal of regional anesthesia: alleviation of pain and increased comfort during the perioperative period. Some even argue that, if regional anesthesia does not provide any long-term benefits, then why bother administering it? The study by Ironfield et al1 demonstrates that, among patients who received a peripheral nerve block for their surgery, almost 95% of those patients would be willing to have another block for future surgery. Although regional anesthesia is gaining popularity as a modality for controlling pain, general anesthesia and opioidbased analgesia remains the most prevalent means of managing pain during and after surgery. In this regard, many individuals
I
265
Copyright © 2014 American Society of Regional Anesthesia and Pain Medicine. Unauthorized reproduction of this article is prohibited.
Letters to the Editor
who undergo surgery will never experience the benefits of regional anesthesia but will otherwise be satisfied with their care in terms of pain control. Likewise, some surgeons and even some anesthesiologists will not attempt to explain the benefits of regional anesthesia to patients because they have either never needed anesthesia themselves, or see no difference between the benefits of general and regional anesthesia, or think that administering a nerve block is just one more time-consuming step before surgery. In essence, the current perspective regarding regional anesthesia versus traditional anesthesia/analgesia methods resembles the options of business class and economy class when traveling on an airline. One might make the argument that there is no need for separate business and economy classes because there is no actual benefit in terms of arrival time: it takes the same amount of time to reach the destination whether you are relaxing in business class or sitting in a cramped seat near the lavatory. However, anyone who has traveled in both business and economy class will attest to the considerable difference between the 2 options with regard to comfort, service, and overall quality. Moreover, those who have traveled in busi-
266
Regional Anesthesia and Pain Medicine • Volume 39, Number 3, May-June 2014
ness class would more than likely choose this option again if they were given the option. Similarly, individuals who receive a nerve block are much more likely to be willing to have another one for future surgery because of their high level of satisfaction with their nerve block the first time. There is a possibility that we are getting distracted from the more important advantages of regional anesthesia by trying to evaluate or quantify its long-term benefits. In trying to prove or justify its long-term benefits, are we in fact asking too much of regional anesthesia? The study by Ironfield et al helps to refocus our attention on the importance of patient satisfaction and wellbeing when deciding on an option for anesthesia. By evaluating patients’ opinions on the immediate benefits of regional anesthesia, rather than assessing some long-term benefit, the article asks the right questions and reminds us that the primary goal of anesthesia is to keep patients free from pain during the perioperative period. In the same way as airlines provide information for passengers regarding the options of business or economy class travel, so too should the anesthesiology community inform the public about their options with respect to pain
management. We want our patients to be as comfortable as possible, and if the option of regional anesthesia is available, should we not promote its effectiveness and advantages over other pain control methods? The study of Ironfield et al does well to remind us that, having had the superior experience offered by a peripheral nerve block, patients will choose this option in the future. What better reason do we need to stop doubting the merits of regional anesthesia?
Ban Chi-Ho Tsui, MD Department of Anesthesiology and Pain Medicine University of Alberta, Edmonton Alberta, Canada
The authors declare no conflict of interest. REFERENCE 1. Ironfield CM, Barrington MJ, Kluger R, Sites B. Are patients satisfied after peripheral nerve blockade? Results from an International Registry of Regional Anesthesia. Reg Anesth Pain Med. 2014;39:48–55.
© 2014 American Society of Regional Anesthesia and Pain Medicine
Copyright © 2014 American Society of Regional Anesthesia and Pain Medicine. Unauthorized reproduction of this article is prohibited.
![[Regional anesthesia procedures in childhood: Austrian interdisciplinary recommendations on pediatric perioperative pain management].](/assets/img/hold.png)
