Is epidural anesthesia truly the best pain management strategy after minimally invasive pectus excavatum repair?

Is epidural anesthesia truly the best pain management strategy after minimally invasive pectus excavatum repair?

Journal of Pediatric Surgery (2008) 43, 79–82 www.elsevier.com/locate/jpedsurg Is epidural anesthesia truly the best pain management strategy after ...

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Journal of Pediatric Surgery (2008) 43, 79–82

www.elsevier.com/locate/jpedsurg

Is epidural anesthesia truly the best pain management strategy after minimally invasive pectus excavatum repair? Shawn D. St Peter⁎, Kathryn A. Weesner, Ronald J. Sharp, Susan W. Sharp, Daniel J. Ostlie, George W. Holcomb III Department of Surgery, The Children’s Mercy Hospital, Kansas City, MO 64108, USA Received 28 August 2007; accepted 2 September 2007

Index words: Pain control; Pectus repair; Epidural anesthesia

Abstract Objective: The repair of pectus excavatum with bar placement is associated with substantial postoperative pain. Optimal pain control strategy has not been addressed with level 1 or substantial level 2 evidence. Many institutions operate under the assumption that a thoracic epidural offers the best pain control for these patients. Therefore, we conducted a retrospective evaluation to examine the validity of this assumption. Methods: A retrospective review of patients undergoing pectus excavatum repair with bar placement from January 2000 to February 2006 was conducted. The demographic variables collected included age, sex, weight, and Haller's index scores. Outcome variables included total operating room time, number of calls to the anesthesiologist, hours of urinary catheterization, hours until complete transition to oral pain medication, length of hospitalization, and maximum pain scores for each of the first 5 postoperative days. Results: There were a total of 203 patients, of which 188 had an epidural, compared with 15 with intravenous narcotic therapy. Of the 188 patients committed to an epidural, 65 had a failed attempt in the operating room or a dysfunctional catheter removed within 24 hours. Patients without an epidural had a shorter operating room time, less time of urinary catheterization, decreased time to complete transition to oral medication, and decreased length of hospitalization with lower maximum scores. Conclusions: Our data challenge the assumption that routine epidural catheter placement on all patients undergoing pectus excavatum repair with bar placement offers the best pain management strategy. There is clearly a role for a prospective randomized trial to clarify the best management for these patients. © 2008 Elsevier Inc. All rights reserved.

Pectus excavatum, the most common chest wall deformity, occurs in roughly 1 in 1000 children [1]. Operative repair of the anterior thoracic concavity has transitioned to the minimally invasive approach with substernal bar placement through small axillary incisions (Nuss procedure and multiple modifications). These procedures were promptly incorpoPresented at the 38th annual meeting of the American Pediatric Surgical Association, Orlando, Florida, May 24-27, 2007. ⁎ Corresponding author. Tel.: +1 816 234 3575; fax: +1 816 983 6885. E-mail address: [email protected] (S.D. St Peter). 0022-3468/$ – see front matter © 2008 Elsevier Inc. All rights reserved. doi:10.1016/j.jpedsurg.2007.09.024

rated by high volume centers around the world including our own [2-7]. The operation is certainly quicker and associated with less blood loss than the open operation, but as opposed to most minimally invasive versions of an operation, patients do not leave the hospital sooner after bar placement and experience more postoperative pain [6-8]. Pain during the postoperative hospital stay is the dominant management issue after bar placement. The sparse literature on the topic has suggested that a thoracic epidural is the most effective means for attenuating the pain during the first few postoperative days [9-11]. Therefore, most centers

80 approach all patients undergoing a pectus deformity repair with an attempt at epidural placement under the assumption that this provides the most effective strategy for pain control [3-8,12]. We conducted a retrospective evaluation to examine the validity of this assumption and to investigate whether there is a role for a prospective study to determine the optimum postoperative management of these patients.

1. Methods After approval from the institutional review board, retrospective review was conducted of our patients undergoing pectus excavatum repair with bar placement from January 2000 to February 2006. Comparative groups were established based on the pain management strategy planned for the patient. Groups were recorded as intention to treat with epidural regional analgesia (epidural) or patient controlled intravenous systemic analgesia (PCA). Within the group of patients in whom an epidural was attempted, 2 subgroups exist: those who did not have an epidural functioning within 24 hours and those whose epidural functioned beyond 24 hours. All patients with an epidural or PCA were managed by the anesthesiology team until they were transitioned or oral pain medications per institutional protocol. Calls from nursing regarding pain management were directed to the anesthesiology team until this transition occurred. Demographic variables investigated age, sex, weight, and Haller's index scores. Outcome variables included total operating room time, number of calls to the anesthesiologist, hours of urinary catheterization, hours until complete transition to oral pain medication, length of hospitalization, and maximum pain scores for each of the first 5 postoperative days. The epidural group was compared against the PCA group with 2-tailed Student's t test. Including the subset groups of epidural patients, we then compared the 4 groups using analysis of variance for continuous variables and χ2 for discrete variables. Continuous variables are listed in the tables as mean ± SE. Subjective pain scores were not evaluated with comparative statistics.

S.D. St Peter et al. Table 1 Group

Demographics Age (y)

Epidural 13.9 ± 0.2 (n = 188) PCA 14.1 ± 0.8 (n = 15) Epidural b24 h 13.7 ± 0.4 (n = 65) Epidural N24 h 14.0 ± 0.3 (n = 123) P .79

Weight (kg)

Sex (male/ Haller's female) index

49.5 ± 1.1 150:33

4.3 ± 0.1

49.0 ± 3.7 14:1

4.3 ± 0.3

50.1 ± 1.7 52:12

4.4 ± 0.2

49.2 ± 1.4 97:26

4.2 ± 0.1

.91

.88

.58

24 hours of surgery and removed. The placement failure was recognized in the operating room in 59 of these patients, and the other 6 patients were switched to PCA in the postoperative care area or the floor. There were 123 patients who were then in the epidural group for greater than 24 hours. At operation, there were no differences between the groups in demographics (Table 1). Patients with a functioning epidural over 24 hours had the catheter removed at a mean of 53 hours (2.2 days). Intent-totreat analysis comparisons between all patients with attempted epidural vs those with straight PCA are listed in Table 2. In this comparison, operating time, hours to oral pain medications, and length of stay were all significantly longer in the epidural group. All groups including subgroups of epidural patients are compared in Table 3. Multigroup comparison found differences in operating time and calls to anesthesia. It is notable that the difference between the epidural group and the PCA group in operating time was in the time before incision was made. The mean time in the operating room before incision in the epidural group was 52 minutes compared with 29 minutes in the PCA group. Maximum daily pain scores were remarkably similar between groups (Fig. 1). The pain scores were slightly better in the PCA group for each of the first 4 postoperative days, and there were no scores for postoperative day 5 because the patients were discharged to home.

3. Discussion 2. Results During the study period, there were 203 patients who underwent pectus excavatum repair with modified Nuss technique as previously described [6]. There were 188 patients in whom epidural was intended as the pain management strategy compared with 15 patients treated with PCA de novo. Within the epidural group, there were 65 patients (35%) in whom the epidural catheter could not be placed, was technically tenuous, or was no longer functioning within

Pain is the single dominant factor determining the quality of the postoperative course of patients with pectus bar placement for pectus excavatum perspective of the patient. Furthermore, the management of pain will influence all measurable objective outcome parameters during their hospital stay, such as ability to tolerate oral intake, ambulation, deep breathing/atelectasis, days until urinary catheter removal, days until complete transition to oral medications, and length of stay. In spite of this, there is very little published addressing the optimal management strategy for postoperative pain and nothing in the past 10 years in the

Epidural versus PCA in pectus excavatum repair Table 2

81

Outcomes—epidural vs PCA

Group

Epidural

OR time (h:min) Calls to anesthesia Hours to Foley out Hours to postoperative oral medications Length of stay (h:min)

1:48 1.7 59:37 61:01

± 0:02 ± 0.1 ± 1:35 ± 1:32

103:42 ± 1:58

PCA 1:25 ± 1.1 ± 50:24 ± 49:36 ±

P 0:06 0.4 4:34 4:22

.004 .240 .190 .042

88:20 ± 8:20

.037

OR, operating room; Foley, Foley catheter.

pediatric surgical literature. This is the same time frame in which the minimally invasive pectus bar operation has blossomed to replace the open operation that causes less pain than bar placement [8]. Because the thoracic epidural has been described in children for this operation as feasible and useful [10], it has been widely applied as the standard for pain control in the early postoperative days after bar placement. The concept that an epidural is the best possible management for these patients is based on several assumptions, namely, that patients will be numb in the distribution of the operation, allowing them to take deep breaths after the operation. This would avoid the respiratory depression associated with systemic narcotics. This assumption depends on the scenario where there will be minimal problems with the catheters, the distribution of analgesia will be accurate, and the placement will be technically feasible in most patients. In our experience, 35% of patients have not had successful catheter placement. The percentage of epidural failure has not been previously published in a large series; thus, we do not know if this number is high, low, or representative of most institutions. However, in a small series of 19 patients, 50% of the patients required intravenous support, which alludes to a high failure rate [10]. Many of these patients had their epidural removed on the floor after it was discovered they were not working, which makes for a rocky transition to PCA as reflected by slightly higher pain scores in this group. It may be true that the perfectly placed and properly functioning epidural may offer good pain control for an individual patient. However, when applied to the entire Table 3

Fig. 1 Line graph of the mean maximum pain scores for each of the first 5 postoperative days.

population, this effect is diluted by the high failure rate of epidural placement, catheter dysfunction, or ineffective distribution. Even in the scenario of a functioning catheter, the pain is controlled at the expense of addition operating room time, longer time to oral medications, and increased length of hospitalization (Table 2). The increased time to oral medications and discharge is likely because of additional steps required to transition off the epidural when the patient requires a PCA bridge. In the PCA group, it is easier to begin titrating oral medications early to facilitate a complete transition before what is possible in the epidural group. The most striking from these data is that the group with a functioning epidural for over 24 hours did not have better pain scores than the PCA group. In fact, the scores were slightly lower in the PCA group (Fig. 1). There is no obvious reason for this observation when carefully looking at our data collection points and our nurse recording system. Granted, the number of patients in the PCA group is small, but the variance around the mean is small, implying this number is not skewed by a few. It is important to note that pain scores are subjective estimates made by the patient; therefore, the individual numbers generated are not

Outcomes—all groups

Group

OR time (h:min) Calls to anesthesia Hours to postoperative medications Hours to Foley out Length of stay (h:min)

Epidural (n = 190) PCA EPI b24 h (n = 80) EPI N24 h (n = 110) P

1:48 ± :02

1.7 ± 0.1

61:01 ± 1:32

59:37 ± 1:35

103:42 ± 1:58

1:25 ± 0:06 1:40 ± 0:03

1.1 ± 0.4 1.0 ± 0.2

49:36 ± 4:22 59:05 ± 2:44

50:24 ± 4:34 56:00 ± 3:28

88:20 ± 8:20 101:33 ± 3:37

1:51 ± 0:03

2.0 ± 0.2

62:03 ± 1:52

60:56 ± 1:42

104:50 ± 2:10

.002

.001

.16

.33

.16

OR, operating room; EPI, epidural catheter.

82 valid objective integers to which comparative statistics should be applied. As such, we cannot conclude with certainty that patients with PCA experience less pain or have a superior postoperative management than patients with an epidural. However, these data certainly challenges the assumption that an epidural catheter offers the optimum management for these patients and convincingly answers the question as to whether there is a role for a prospective randomized trial.

References [1] Nuss D, Croitoru DP, Kelly Jr RE, et al. Congenital chest wall deformities In: Holcomb GW III, Ashcraft, KW, Murphy, JP. editors. Pediatric Surgery. Philadelphia, PA, Elsevier Saunders Chapter 19. 245-63. [2] Croitoru DP, Kelly RE Jr, Goretsky MJ, et al. Experience and modification update for the minimally invasive Nuss technique for pectus excavatum repair in 303 patients. J Pediatr Surg 2002; 37:437-45. [3] Swoveland B, Medvick C, Kirsh M, et al. The Nuss procedure for pectus excavatum correction. AORN J 2001;74(6):828-41. [4] Uemura S, Nakagawa Y, Yoshida A, et al. Experience in 100 cases with the Nuss procedure using a technique for stabilization of the pectus bar. Pediatr Surg Int 2003;19:186-9. [5] Park HJ, Lee SY, Lee CS, et al. The Nuss procedure for pectus excavatum: evolution of techniques and early results on 322 patients. Ann Thorac Surg 2004;77(1):289-95. [6] Miller KA, Woods RK, Sharp RJ, et al. Minimally invasive repair of pectus excavatum: a single institution's experience. Surgery 2001;130 (4):652-7. [7] Molik KA, Engum SA, Rescorla FJ, et al. Pectus excavatum repair: experience with standard and minimal invasive techniques. J Pediatr Surg 2001;36:324-8. [8] Fonkalsrud EW. Current management of pectus excavatum. World J Surg 2003;27(5):502-8. [9] Canovas Martinez L, Dominguez Garcia M, Fernandez Gil N, et al. Thoracic epidural analgesia in the postoperative period of pediatric surgery for the repair of pectus excavatum and pectus carinatum. Rev Esp Anestesiol Reanim 1998;45(4):148-52. [10] McBride WJ, Dicker R, Abajian JC, et al. Continuous thoracic epidural infusions for postoperative analgesia after pectus deformity repair. J Pediatr Surg 1996;31(1):105-7. [11] Futagawa K, Suwa I, Okuda T, et al. Anesthetic management for the minimally invasive Nuss procedure in 21 patients with pectus excavatum. J Anesth 2006;20:48-50. [12] Bohosiewicz J, Kudela G, Koszutski T. Results of Nuss procedures for the correction of pectus excavatum. Eur J Pediatr Surg 2005;15:6-10.

S.D. St Peter et al.

Discussion Doctor: Could you please comment on what agent you use in the epidural and the use of adjuvant anxiolytics and muscle relaxants? Shawn St. Peter, MD (Kansas City, MO): We have 22 anesthesiologists in the group, and there were at least 22 different types of epidurals in this study. For the prospective study, we now have a unified protocol for both arms. Doctor: Is the same true for the PCA? Shawn St. Peter, MD (response): Yes. The mantra in developing this study to the anesthesiologists was best foot forward, so I had a group of 5 that were willing to participate. Everybody else was reluctant. Of those 5, they came up with a protocol that they agreed would be the best for both PCA and for epidural. Interestingly, the length of stay in the prospective study—we are limiting it. On postoperative day 3, the anesthesiologist puts the order in for the transition and leave the catheter in to see if they can transition because I think the length of stay may be artificially inflated in the retrospective study because, as long as the patient is doing well, they are not forced to transition. David Rodeberg, MD (Pittsburgh, PA): Shawn, I have 2 questions for you. One, was Toradol given to any of the groups? I find that a nonsteroidal is frequently helpful. Also, the pain seems to be worse in the Nuss procedure in adolescent children as compared to younger children. Was there an age distribution discrepancy between the 2 groups? Shawn St. Peters, MD (response): I did not do an age distribution analysis on this data. Our perception is the exact same. I think it is very difficult to have a younger child understand what kind of a hit they are going to take. I think a teenager understands a little bit better that they are going to have to learn to be comfortable with being uncomfortable, and so they do a little bit better. Toradol was given to all the patients.