- Email: [email protected]
Reply to Dr. Price
Letters to the Editor
What Local Anesthetic Volume Should Be Used for Suprascapular Nerve Block? To the Editor: I would like to congratulate Dr. Feigl and his coauthors on a very interesting investigation into the anatomy of the supraspinous fossa.1 In addition to delineating that anatomy, it also offers another safe approach to blocking the suprascapular nerve. I have extensive personal experience at blocking this nerve, which I primarily block in conjunction with the axillary (circumflex) nerve as an alternative to interscalene brachial plexus block for the control of postoperative pain following shoulder surgery.2 I also use it in conjunction with a high epidural for control of pain following thoracoscapular fusion.3 I have performed more than 100 combined suprascapular and axillary nerve blocks, and currently use the technique described by Meier to block the suprascapular nerve,4 which I have found safe, reliable, and effective. As I perform the blocks as a single shot technique primarily for postoperative pain relief, I have been using 15 mL of 0.75% ropivacaine in each case (Meier recommends 10 to 15 mL) in order to prolong that analgesia. I also use 15 mL of 0.75% ropivacaine when blocking the axillary nerve as it crosses the posterior surface of the neck of the humerus, beneath the posterior deltoid. I have not performed a study to examine the duration of analgesia from both of these blocks, but have followed up each case to determine when the block might have worn off, and my clinical impression is that it lasts longer than a single shot interscalene block. I have also not investigated using smaller doses of local anesthetic on each nerve, but one might suppose that the duration of action of a 15 mL dose significantly exceeds that of a 5 mL dose of the same agent. It appears there is no increased risk using 15 mL doses, and in both Meier’s suprascapular nerve block and the axillary nerve block there is not an accompanying sensation of a potentially dangerous rise in pressure upon injection. So while I am convinced by Dr. Feigl’s findings that 5 mL is sufficient to fill the space, I wonder if it is sufficient to give the block adequate duration of action.
3. Price DJ. High thoracic epidural plus suprascapular nerve block analgesia for thoracoscapular fusion. Reg Anesth Pain Med 2007;32:541-542. 4. Meier G, Buettner J. Suprascapular nerve block. In: Peripheral Regional Anesthesia: An Atlas of Anatomy and Techniques. Stuttgart: Thieme; 2006:48-54.
Accepted for publication February 29, 2008. doi:10.1016/j.rapm.2008.02.005
Reply to Dr. Price To the Editor: Thank you for the opportunity and honor to reply to the letter of Price1 concerning the volumes to be used for an efficient suprascapular nerve block. Since the development of techniques to block the nerve in the supraspinous fossa, different volumes from 5 to 15 mL have been proposed by several authors. All of them applied the volumes into the supraspinous fossa, and they report effective and long lasting block. Nevertheless, there has been discussion and research to find the ideal volume for efficient blocks that additionally have been addressed by Feigl et al.2 Feigl et al.2 describe, in a strictly morphological investigation, a modified lateral block of the suprascapular nerve with a proposal to use 5 mL. Price uses the technique described by Meier et al.3 by injecting a 15 mL volume and has excellent experience by having performed more than 100 blocks, which we honor respectfully. Therefore we understand Price’s concern that low volumes of 5 mL may result in shorter lasting blocks. However, different morphological arguments strongly strengthen Feigl’s proposal of the use of 5 mL: ●
Darcy J. Price, M.B.Ch.B., F.A.N.Z.C.A. North Shore Hospital Auckland, New Zealand References 1. Feigl GC, Anderheuber F, Dorn C, Pipam W, Rosmarin W, Likar R. Modified lateral block of the suprascapular nerve: A safe approach and how much to inject? A morphological study. Reg Anesth Pain Med 2007;32:488-494. 2. Price DJ. The shoulder block: A new alternative to interscalene brachial plexus blockade for the control of postoperative shoulder pain. Anaesth Intensive Care 2007;35:575-581.
●
Anatomy of the fossa: As described in anatomical textbooks, the supraspinous fossa is a strictly limited compartment and is filled with the supraspinous muscle. Its fibers originate from the osseous walls of this fossa and from the supraspinous fascia, which is well developed especially in the medial part. The fascia is thinner in the lateral part of the fossa and even may be absent. Such morphology favors the spread of local anesthetic in the lateral part of the fossa and may prohibit the dissemination to its medial parts due to higher resistances. The higher the injected volume, the more the local anesthetic will spread medially. Regarding the technique of Feigl, the tip of the needle arrives in the lateral part, with consecutive dissemination in this area where the nerve enters the fossa. Course of the suprascapular nerve: The nerve originates from the supraclavicular part of the brachial plexus, runs laterally toward the suprascapular notch, and enters the supraspinous fossa under
Regional Anesthesia and Pain Medicine, Vol 33, No 6 (November–December), 2008: pp 571–575
571
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Regional Anesthesia and Pain Medicine Vol. 33 No. 6 November–December 2008
●
Fig 1. Superior view of a right supraspinous fossa: the clavicle and lateral aspect of acromion are removed. The yellow underplayed suprascapular nerve (SSN) enters the supraspinous underneath the superior transverse scapular ligament (STSL), divides into branches to the suprascapular muscle (SSM) and glenohumeral joint (1), and continues as a trunk. Anatomical landmarks are the coracoid process (CP), and the spine of scapula (SoS).
the superior transverse scapular ligament (Fig 1). The suprascapular notch is found quite laterally and lies directly medial to the base of the coracoid process. From this point on, anatomical textbooks do not provide satisfying detailed information of the more peripheral branching and course of the nerve. More details are given by Bigliani et al.,4 who investigated 90 specimens from the arthroscopic point of view. According to their results, the nerve enters the fossa through the scapular notch and inferior to the superior transverse scapular ligament in all cases, and branches within 1 cm by sending fibers to the supraspinous muscle and glenohumeral joint capsule, and the acromioclavicular joint capsule3 (Fig 1). Additionally, some fibers are sent to the acromion. The main trunk of the nerve runs laterally and inferior to the supraspinous muscle, and around the base of the scapular spine. The description by Bigliani et al. is confirmed by Ozer et al .,5 who investigated 17 fresh cadavers. Ozer et al.5 mention cases where the suprascapular nerve splits into 2 or 3 branches before entering the notch. Nevertheless, all branches commonly run through the notch to enter the fossa. This is in agreement with our own observations of about 500 dissected cadavers over the last 15 years (Fig 1). Additionally, Ozer et al.5 describe ossifications of the notch that may lead the nerve to enter the fossa more inferiorly but still laterally. We also found similar variations (Fig 2), where the nerve runs with an inferior part directly through the scapula. Such unusual courses will be reached with our technique as well because the tip of the needle is not very far away from the main trunk of the nerve (Fig 2). With the confirmation by our computed tomography investigation of the spread by 3-dimensional reconstruction and verifying dissection, our technique provides a
local spread in the lateral area of the fossa, where the main trunk of the suprascapular nerve resides, but not mainly into the medial parts of the fossa. The latter spread, which we already observed with the use of 5 mL, is totally unnecessary because there are no nerve fibers entering medially. Furthermore, our findings confirm that the use of higher volumes fills the entire fossa. Recommendation and technique of Meier et al.:3 In the original article of Meier et al., the authors describe a minimal use of 10 mL. For the catheter technique they start with a higher initial dose of 15 mL. By injecting 10 mL of volume they remarked on an increase of pressure, which was interpreted as a filled fossa. The additional injection of another 5 mL is to force volume out of the scapular notch. This may allow us to assume that even a smaller dose may lead to the same results. Inspecting Meier’s technique more carefully, the local anesthetic will spread laterally, because of a laterally-directed needle. Certainly, a medial spread can be less prohibited because the needle enters the fossa much more medially than with Feigl’s technique. Therefore, it is quite understandable that Meier proposes a higher initial volume than we, even for a single shot technique.
These points strengthen our opinion that the use of 5 mL should be enough to result in satisfying blocks from the morphological and radiological points of view. Nevertheless, we know that our results are based on detailed morphological data only, and the findings are combined with a lot of experience on the anatomical platform. Certainly, we agree with Price that without any clinical
Fig 2. Superior view of a right supraspinous fossa: the suprascapular nerve (SSN) divides into 2 branches before reaching the scapular notch. The yellow underplayed inferior branch (1) runs through an osseous tunnel and enters the fossa directly underneath the supraspinous muscle (SSM). The superior branch (2) enters underneath a thin superior transverse scapular ligament (STSL). The white circle shows the position of the needle tip. Additional landmarks are the clavicle (Cl), spine of scapula (SoS), and the acromioclavicular joint (ACJ).
Letters to the Editor verification, our morphological findings are only assumptions. As a consequence, a clinical study to evaluate the modified lateral suprascapular nerve block is underway, and we are looking forward to presenting these data and results as soon as possible. Reporting of preliminary results would be inappropriate. Georg Christoph Feigl, M.D. Friedrich Anderhuber, M.D. Department of Anatomy Medical University Graz Graz, Austria Christian Dorn, M.D. Departments of Anesthesiology and Intensive Medicine Medical University Graz Graz, Austria Rudolph Likar, M.D. Department of Anesthesiology and Intensive Medicine Hospital Klagenfurt Klagenfurt, Austria References 1. Price DJ. What local anesthetic volume should be used for the suprascapular nerve block? Reg Anesth Pain Med 2008;33: 571. 2. Feigl GC, Anderhuber F, Dorn C, Pipam W, Rosmarin W, Likar R. Modified lateral block of the suprascapular nerve: A safe approach and how much to inject? A morphological study. Reg Anesth Pain Med 2007;32:488-494. 3. Meier G, Bauereis C, Maurer H. The modified technique of continuous suprascapular nerve block. A safe technique in the treatment of shoulder pain. Anaesthesist 2002;51:727-753. 4. Bigliani LU, Dalsey RM, McCann PD, April EW. An anatomical study of the suprascapular nerve. Arthroscopy 1990;6:301305. 5. Ozer Y, Grossman JA, Gilbert A. Anatomic observations on the suprascapular nerve. Hand Clin 1995;11:539-544.
573
to characterize undiagnosed valvular lesions, and to assess ventricular function in an attempt to minimize risk by avoiding certain anesthetic techniques. I therefore wonder why 22 patients out of 1,947 patients undergoing HEA total hip replacement were preoperatively identified as having aortic stenosis (AS) yet were still given an anesthetic that is widely regarded as contraindicated in this patient group. The second issue that the study raises is that 11 of the 22 patients (50%) underwent a postoperative “rule-out myocardial infarction protocol.” The authors do not expand on what triggers are used for the “rule-out myocardial infarction protocol,” or what proportion of the remaining 1,925 patients, whom we assume did not have AS, also triggered this protocol. The final point, which the authors raise themselves, relates to the lack of a control group in this study. It would have been interesting, and relatively easy, to have provided data on the remaining 1,925 patients, or a selected subgroup of these remaining patients, who had no valvular lesions on preoperative echocardiogram. To be able to compare the AS group with a nonAS group with regard to baseline characteristics, ejection fraction, duration of stay in the monitored setting of the post anesthesia care unit, total days hospitalized, as well as perioperative data (blood pressure, central venous pressure, epinephrine, intravenous fluid, and blood use, etc.) would have served 2 purposes. It would have given the reader a better insight into any differences between these 2 patient groups which may affect the anesthetist during the perioperative period, and it would have added weight to the argument that this method is safe in patients with AS in the hands of these authors (assuming the data were indeed comparable). James Sinclair Dawson, B.Sc., M.B. Ch.B Anaesthetics and Critical Care United Lincolnshire Hospitals NHS Trust Lincoln County Hospital Lincoln, Lincolnshire United Kingdom
Accepted for publication May 7, 2008. doi:10.1016/j.rapm.2008.05.005 Reference
Epidurals in Aortic Stenosis To the Editor: I read with great interest the article by Ho et al.1 and applaud them for reducing their rates of in-hospital mortality following the introduction of hypotensive epidural anesthesia (HEA). This publication does raise questions, however, about their clinical practice, study methodology, and the presentation of their findings. The first relates to their clinical practice, especially in preoperative assessment of patients undergoing HEA for total hip replacement, and whether they employ any exclusion criteria when considering patients for HEA. It is unclear from their current study if all patients have a preoperative transthoracic echocardiogram or if this is reserved for specific subgroups of patients (e.g., patients with cardiac murmurs). The use of a preoperative transthoracic echocardiogram is often
1. Ho MC, Beathe JC, Sharrock NE. Hypotensive epidural anesthesia in patients with aortic stenosis undergoing total hip replacement. Reg Anesth Pain Med 2008;33:129-133.
Accepted for publication March 31, 2008. doi:10.1016/j.rapm.2008.03.005
Epidural Catheters Without Holes To the Editor: Epidural anesthesia and analgesia for postoperative pain and labor are used worldwide. Although it is a safe technique, it is not without complications. Multiorifice catheters have shown to be superior to single orifice catheters for labor analgesia and cesarean delivery.1 The inability to administer fluids through the catheter may be due to intralu-
What Local Anesthetic Volume Should Be Used for Suprascapular Nerve Block? To the Editor: I would like to congratulate Dr. Feigl and his coauthors on a very interesting investigation into the anatomy of the supraspinous fossa.1 In addition to delineating that anatomy, it also offers another safe approach to blocking the suprascapular nerve. I have extensive personal experience at blocking this nerve, which I primarily block in conjunction with the axillary (circumflex) nerve as an alternative to interscalene brachial plexus block for the control of postoperative pain following shoulder surgery.2 I also use it in conjunction with a high epidural for control of pain following thoracoscapular fusion.3 I have performed more than 100 combined suprascapular and axillary nerve blocks, and currently use the technique described by Meier to block the suprascapular nerve,4 which I have found safe, reliable, and effective. As I perform the blocks as a single shot technique primarily for postoperative pain relief, I have been using 15 mL of 0.75% ropivacaine in each case (Meier recommends 10 to 15 mL) in order to prolong that analgesia. I also use 15 mL of 0.75% ropivacaine when blocking the axillary nerve as it crosses the posterior surface of the neck of the humerus, beneath the posterior deltoid. I have not performed a study to examine the duration of analgesia from both of these blocks, but have followed up each case to determine when the block might have worn off, and my clinical impression is that it lasts longer than a single shot interscalene block. I have also not investigated using smaller doses of local anesthetic on each nerve, but one might suppose that the duration of action of a 15 mL dose significantly exceeds that of a 5 mL dose of the same agent. It appears there is no increased risk using 15 mL doses, and in both Meier’s suprascapular nerve block and the axillary nerve block there is not an accompanying sensation of a potentially dangerous rise in pressure upon injection. So while I am convinced by Dr. Feigl’s findings that 5 mL is sufficient to fill the space, I wonder if it is sufficient to give the block adequate duration of action.
3. Price DJ. High thoracic epidural plus suprascapular nerve block analgesia for thoracoscapular fusion. Reg Anesth Pain Med 2007;32:541-542. 4. Meier G, Buettner J. Suprascapular nerve block. In: Peripheral Regional Anesthesia: An Atlas of Anatomy and Techniques. Stuttgart: Thieme; 2006:48-54.
Accepted for publication February 29, 2008. doi:10.1016/j.rapm.2008.02.005
Reply to Dr. Price To the Editor: Thank you for the opportunity and honor to reply to the letter of Price1 concerning the volumes to be used for an efficient suprascapular nerve block. Since the development of techniques to block the nerve in the supraspinous fossa, different volumes from 5 to 15 mL have been proposed by several authors. All of them applied the volumes into the supraspinous fossa, and they report effective and long lasting block. Nevertheless, there has been discussion and research to find the ideal volume for efficient blocks that additionally have been addressed by Feigl et al.2 Feigl et al.2 describe, in a strictly morphological investigation, a modified lateral block of the suprascapular nerve with a proposal to use 5 mL. Price uses the technique described by Meier et al.3 by injecting a 15 mL volume and has excellent experience by having performed more than 100 blocks, which we honor respectfully. Therefore we understand Price’s concern that low volumes of 5 mL may result in shorter lasting blocks. However, different morphological arguments strongly strengthen Feigl’s proposal of the use of 5 mL: ●
Darcy J. Price, M.B.Ch.B., F.A.N.Z.C.A. North Shore Hospital Auckland, New Zealand References 1. Feigl GC, Anderheuber F, Dorn C, Pipam W, Rosmarin W, Likar R. Modified lateral block of the suprascapular nerve: A safe approach and how much to inject? A morphological study. Reg Anesth Pain Med 2007;32:488-494. 2. Price DJ. The shoulder block: A new alternative to interscalene brachial plexus blockade for the control of postoperative shoulder pain. Anaesth Intensive Care 2007;35:575-581.
●
Anatomy of the fossa: As described in anatomical textbooks, the supraspinous fossa is a strictly limited compartment and is filled with the supraspinous muscle. Its fibers originate from the osseous walls of this fossa and from the supraspinous fascia, which is well developed especially in the medial part. The fascia is thinner in the lateral part of the fossa and even may be absent. Such morphology favors the spread of local anesthetic in the lateral part of the fossa and may prohibit the dissemination to its medial parts due to higher resistances. The higher the injected volume, the more the local anesthetic will spread medially. Regarding the technique of Feigl, the tip of the needle arrives in the lateral part, with consecutive dissemination in this area where the nerve enters the fossa. Course of the suprascapular nerve: The nerve originates from the supraclavicular part of the brachial plexus, runs laterally toward the suprascapular notch, and enters the supraspinous fossa under
Regional Anesthesia and Pain Medicine, Vol 33, No 6 (November–December), 2008: pp 571–575
571
572
Regional Anesthesia and Pain Medicine Vol. 33 No. 6 November–December 2008
●
Fig 1. Superior view of a right supraspinous fossa: the clavicle and lateral aspect of acromion are removed. The yellow underplayed suprascapular nerve (SSN) enters the supraspinous underneath the superior transverse scapular ligament (STSL), divides into branches to the suprascapular muscle (SSM) and glenohumeral joint (1), and continues as a trunk. Anatomical landmarks are the coracoid process (CP), and the spine of scapula (SoS).
the superior transverse scapular ligament (Fig 1). The suprascapular notch is found quite laterally and lies directly medial to the base of the coracoid process. From this point on, anatomical textbooks do not provide satisfying detailed information of the more peripheral branching and course of the nerve. More details are given by Bigliani et al.,4 who investigated 90 specimens from the arthroscopic point of view. According to their results, the nerve enters the fossa through the scapular notch and inferior to the superior transverse scapular ligament in all cases, and branches within 1 cm by sending fibers to the supraspinous muscle and glenohumeral joint capsule, and the acromioclavicular joint capsule3 (Fig 1). Additionally, some fibers are sent to the acromion. The main trunk of the nerve runs laterally and inferior to the supraspinous muscle, and around the base of the scapular spine. The description by Bigliani et al. is confirmed by Ozer et al .,5 who investigated 17 fresh cadavers. Ozer et al.5 mention cases where the suprascapular nerve splits into 2 or 3 branches before entering the notch. Nevertheless, all branches commonly run through the notch to enter the fossa. This is in agreement with our own observations of about 500 dissected cadavers over the last 15 years (Fig 1). Additionally, Ozer et al.5 describe ossifications of the notch that may lead the nerve to enter the fossa more inferiorly but still laterally. We also found similar variations (Fig 2), where the nerve runs with an inferior part directly through the scapula. Such unusual courses will be reached with our technique as well because the tip of the needle is not very far away from the main trunk of the nerve (Fig 2). With the confirmation by our computed tomography investigation of the spread by 3-dimensional reconstruction and verifying dissection, our technique provides a
local spread in the lateral area of the fossa, where the main trunk of the suprascapular nerve resides, but not mainly into the medial parts of the fossa. The latter spread, which we already observed with the use of 5 mL, is totally unnecessary because there are no nerve fibers entering medially. Furthermore, our findings confirm that the use of higher volumes fills the entire fossa. Recommendation and technique of Meier et al.:3 In the original article of Meier et al., the authors describe a minimal use of 10 mL. For the catheter technique they start with a higher initial dose of 15 mL. By injecting 10 mL of volume they remarked on an increase of pressure, which was interpreted as a filled fossa. The additional injection of another 5 mL is to force volume out of the scapular notch. This may allow us to assume that even a smaller dose may lead to the same results. Inspecting Meier’s technique more carefully, the local anesthetic will spread laterally, because of a laterally-directed needle. Certainly, a medial spread can be less prohibited because the needle enters the fossa much more medially than with Feigl’s technique. Therefore, it is quite understandable that Meier proposes a higher initial volume than we, even for a single shot technique.
These points strengthen our opinion that the use of 5 mL should be enough to result in satisfying blocks from the morphological and radiological points of view. Nevertheless, we know that our results are based on detailed morphological data only, and the findings are combined with a lot of experience on the anatomical platform. Certainly, we agree with Price that without any clinical
Fig 2. Superior view of a right supraspinous fossa: the suprascapular nerve (SSN) divides into 2 branches before reaching the scapular notch. The yellow underplayed inferior branch (1) runs through an osseous tunnel and enters the fossa directly underneath the supraspinous muscle (SSM). The superior branch (2) enters underneath a thin superior transverse scapular ligament (STSL). The white circle shows the position of the needle tip. Additional landmarks are the clavicle (Cl), spine of scapula (SoS), and the acromioclavicular joint (ACJ).
Letters to the Editor verification, our morphological findings are only assumptions. As a consequence, a clinical study to evaluate the modified lateral suprascapular nerve block is underway, and we are looking forward to presenting these data and results as soon as possible. Reporting of preliminary results would be inappropriate. Georg Christoph Feigl, M.D. Friedrich Anderhuber, M.D. Department of Anatomy Medical University Graz Graz, Austria Christian Dorn, M.D. Departments of Anesthesiology and Intensive Medicine Medical University Graz Graz, Austria Rudolph Likar, M.D. Department of Anesthesiology and Intensive Medicine Hospital Klagenfurt Klagenfurt, Austria References 1. Price DJ. What local anesthetic volume should be used for the suprascapular nerve block? Reg Anesth Pain Med 2008;33: 571. 2. Feigl GC, Anderhuber F, Dorn C, Pipam W, Rosmarin W, Likar R. Modified lateral block of the suprascapular nerve: A safe approach and how much to inject? A morphological study. Reg Anesth Pain Med 2007;32:488-494. 3. Meier G, Bauereis C, Maurer H. The modified technique of continuous suprascapular nerve block. A safe technique in the treatment of shoulder pain. Anaesthesist 2002;51:727-753. 4. Bigliani LU, Dalsey RM, McCann PD, April EW. An anatomical study of the suprascapular nerve. Arthroscopy 1990;6:301305. 5. Ozer Y, Grossman JA, Gilbert A. Anatomic observations on the suprascapular nerve. Hand Clin 1995;11:539-544.
573
to characterize undiagnosed valvular lesions, and to assess ventricular function in an attempt to minimize risk by avoiding certain anesthetic techniques. I therefore wonder why 22 patients out of 1,947 patients undergoing HEA total hip replacement were preoperatively identified as having aortic stenosis (AS) yet were still given an anesthetic that is widely regarded as contraindicated in this patient group. The second issue that the study raises is that 11 of the 22 patients (50%) underwent a postoperative “rule-out myocardial infarction protocol.” The authors do not expand on what triggers are used for the “rule-out myocardial infarction protocol,” or what proportion of the remaining 1,925 patients, whom we assume did not have AS, also triggered this protocol. The final point, which the authors raise themselves, relates to the lack of a control group in this study. It would have been interesting, and relatively easy, to have provided data on the remaining 1,925 patients, or a selected subgroup of these remaining patients, who had no valvular lesions on preoperative echocardiogram. To be able to compare the AS group with a nonAS group with regard to baseline characteristics, ejection fraction, duration of stay in the monitored setting of the post anesthesia care unit, total days hospitalized, as well as perioperative data (blood pressure, central venous pressure, epinephrine, intravenous fluid, and blood use, etc.) would have served 2 purposes. It would have given the reader a better insight into any differences between these 2 patient groups which may affect the anesthetist during the perioperative period, and it would have added weight to the argument that this method is safe in patients with AS in the hands of these authors (assuming the data were indeed comparable). James Sinclair Dawson, B.Sc., M.B. Ch.B Anaesthetics and Critical Care United Lincolnshire Hospitals NHS Trust Lincoln County Hospital Lincoln, Lincolnshire United Kingdom
Accepted for publication May 7, 2008. doi:10.1016/j.rapm.2008.05.005 Reference
Epidurals in Aortic Stenosis To the Editor: I read with great interest the article by Ho et al.1 and applaud them for reducing their rates of in-hospital mortality following the introduction of hypotensive epidural anesthesia (HEA). This publication does raise questions, however, about their clinical practice, study methodology, and the presentation of their findings. The first relates to their clinical practice, especially in preoperative assessment of patients undergoing HEA for total hip replacement, and whether they employ any exclusion criteria when considering patients for HEA. It is unclear from their current study if all patients have a preoperative transthoracic echocardiogram or if this is reserved for specific subgroups of patients (e.g., patients with cardiac murmurs). The use of a preoperative transthoracic echocardiogram is often
1. Ho MC, Beathe JC, Sharrock NE. Hypotensive epidural anesthesia in patients with aortic stenosis undergoing total hip replacement. Reg Anesth Pain Med 2008;33:129-133.
Accepted for publication March 31, 2008. doi:10.1016/j.rapm.2008.03.005
Epidural Catheters Without Holes To the Editor: Epidural anesthesia and analgesia for postoperative pain and labor are used worldwide. Although it is a safe technique, it is not without complications. Multiorifice catheters have shown to be superior to single orifice catheters for labor analgesia and cesarean delivery.1 The inability to administer fluids through the catheter may be due to intralu-