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Initial surgical and pain management outcomes after Nuss procedure
Journal of Pediatric Surgery (2010) 45, 1767–1771
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Initial surgical and pain management outcomes after Nuss procedure John C. Densmore ⁎, Danielle B. Peterson, Linda L. Stahovic, Michelle L. Czarnecki, Keri R. Hainsworth, Hobart W. Davies, Laura D. Cassidy, Steven J. Weisman, Keith T. Oldham Children's Hospital of Wisconsin, Milwaukee, WI 53226, USA Medical College of Wisconsin, Milwaukee, WI 53226, USA Received 10 December 2009; revised 26 January 2010; accepted 27 January 2010
Key words: Nuss procedure; Minimally invasive repair of pectus excavatum; Outcomes; Pain management; Epidural
Abstract Purpose: The purpose of this article was to report surgical and pain management outcomes of the initial Nuss procedure experience at the Children's Hospital of Wisconsin (Milwaukee) and to place this experience in the context of the published literature. Methods: The initial 118 consecutive Nuss procedures in 117 patients were retrospectively reviewed with approval of the Children's Hospital of Wisconsin human rights review board. Patient, surgical, complication, and pain descriptors were collected for each case. Statistical methods for comparison of pain strategies included the Kolmogorov-Smirnov test for normality, 1-way repeated measures analysis of variance, and paired t tests. Results: Patient, surgical, and complication descriptors were comparable to other large series. Complication rates were 7% early and 25% late. Epidural success rate was 96.4%. There was 1 episode of recurrence 2 years postbar removal (n = 114). Conclusions: The institution of the Nuss procedure provides a highly desired result with significant complication rates. The ideal approach would deliver this result with lower risk. A pain service-driven epidural administration of morphine or hydromorphone with local anesthetic provides excellent analgesia for patients after Nuss procedure. The success of epidural analgesia is independent of catheter site and adjunctive medications. Ketorolac was an effective breakthrough medication. © 2010 Elsevier Inc. All rights reserved.
Pectus excavatum is the most frequent congenital deformity of the anterior chest wall, affecting 0.8% to 0.14% of the population [1,2]. Because of asymmetric ⁎ Corresponding author. Division of Pediatric Surgery, Department of Surgery, Medical College of Wisconsin, Milwaukee, WI 53226, USA. Tel.: +1 414 266 6550; fax: +1 414 266 6579. E-mail address: [email protected] (J.C. Densmore). 0022-3468/$ – see front matter © 2010 Elsevier Inc. All rights reserved. doi:10.1016/j.jpedsurg.2010.01.028
cartilaginous growth, this condition results in a concavity of the precordium with a resultant restrictive pulmonary defect and decreased aerobic capacity when compared to agematched controls [2-5]. The role of surgery in reversal of these defects remains controversial; however, many patients perceive improvement [4,6-12]. Surgical correction has been correlated with positive outcomes and improvement of body image [13,14]. With the demand for minimally invasive
1768 surgical approaches increasing, the surgical repair of pectus excavatum has largely shifted away from the Ravitch repair. Recent innovations have included the use of substernal magnets, vacuum lifters, and the Nuss procedure [15-18]. The Nuss procedure is the most common minimally invasive repair of pectus excavatum and corrects the point of maximal concavity using a thoracoscopically directed transthoracic convex substernal bar. Although patients undergoing the Nuss procedure enjoy a smaller scar, significant postoperative pain results from an instantaneous substernal correction. Successful management of post-Nuss procedure pain is a priority as pain decreases patient satisfaction and increases complication rates [19]. Pain management strategies have included systemic opioids via patient-controlled analgesia (PCA), nonsteroidal antiinflammatory medications, hypnosis, and regional anesthesia (opioid, local anesthetic, and αblockade) [19-27]. Although large series demonstrate that modern pain control strategies are adequate, the optimal technique has yet to be clearly determined [3,27,28]. Two small prospective randomized trials have been completed in children examining the efficacy of morphine or fentanyl PCA vs fentanyl/local anesthetic epidural analgesia. One study demonstrated no significance difference in visual analog pain scores or complication rates between fentanyl PCA and fentanyl/bupivacaine epidural treatment in 28 children [21]. A second study randomized 40 children between morphine PCA and fentanyl/ropivacaine epidural treatment. The results of this study demonstrate lower visual analog pain scores in the epidural group [29]. Given the lipophilic nature of fentanyl and its rapid dissemination into a large volume of distribution, the results of fentanyl epidural catheter treatments do not use the specificity of the epidural space afforded by other opioids. Adult thoracotomy pain studies have shown equivalent pain control with fentanyl treatment independent of site of administration [30]. The purpose of this review was to summarize the initial surgical outcomes and detail the pain management strategy used at the Children's Hospital of Wisconsin (Milwaukee). This experience is useful for other institutions building experience with the Nuss procedure given the significant learning curve described by other groups [27,31-36].
1. Materials and methods After approval from the Children's Hospital of Wisconsin Human Rights Review Board, a retrospective chart review was conducted for patients undergoing the Nuss procedure for pectus excavatum repair at between 1999 and 2004. All consecutive cases of Nuss procedure were included in this interval. Patient data were collected 2 years after removal of the Nuss bar. Using anonymous case numbers, the following data were collected: patient descriptors (age, weight, sex, race, pulmonary function, and Haller index), surgical descriptors (number of bars, use of stabilizers, operative
J.C. Densmore et al. time, estimated blood loss, adjunct cartilage resection, length of stay, and cost), complications (early vs late; b vs N 30 postoperative days), and pain management descriptors (PCA or epidural, epidural level, PCA/epidural formulary, number of pain interventions required, medication changes, use of ketorolac, use of clonidine, and pain scores). A specialized team of pediatric anesthesiologists and an advanced practice nurse forming an acute pain management service delivered comprehensive pain management. Patients were transitioned to oral analgesics before hospital discharge. Nursing staff assessed pain scores using the 0 to 10 verbal numeric rating scale (VNRS; 0 = no pain; 10 = worst imaginable pain). Per guidelines, vital signs, pain, and sedation scores were recorded every 2 to 4 hours. All pain descriptors were collected as timed data points. Available Haller indices were calculated from computed tomographic scans by dividing the widest intrapleural coronal chest diameter by the sagittal distance between the point of maximal concavity and the anterior vertebral column at the same level. Statistics were included to examine sample characteristics. Numerical variables were examined for normality using the Kolmogorov-Smirnov test. One-way repeated measures analysis of variance was used to examine pain scores over time. Numerical variable comparisons (eg, ketorolac and clonidine effects) were examined using a paired-samples t test. Significant results used a P value less than .05 for all analyses. Statistical analysis was completed using SPSS, version 11.5 (SPSS Inc, Chicago, Ill).
2. Results 2.1. Patient descriptors Charts of 117 consecutive patients undergoing 118 Nuss procedures were reviewed. The mean age at Nuss bar placement was 12.9 years (SD, 4.8). Mean weight was 46.7 kg (SD, 17.4). Seventy-five percent of patients were male. The ethnicity of our cohort was 93% white, 3% Hispanic, and 4% “other.” There were no African American, Asian, or American Indian patients. Preoperative pulmonary function tests were completed in 28 patients (24%). These tests demonstrated a forced expiratory volume in 1 second of 89% of predicted (SD, 13), an forced vital capacity of 92% of predicted (SD, 13) and forced expiratory volume in 1 second– forced vital capacity ratio of 0.9 (SD, 0.1). The average Haller index was 4.0 (SD, 1.5; n = 65). Three patients had previous chest surgery, 4 had connective tissue disorders, and 2 patients had ulcerative colitis treated with 6-mercaptopurine.
2.2. Surgical descriptors This patient series was the experience of 9 surgeons, all trained in either pediatric or pediatric cardiothoracic
Management outcomes after Nuss procedure surgery. Most patients required a single bar (93%) and bilateral stabilizer placement (70%). A mean of 2.75 stabilizers was used in patients requiring 2 bars for repair. Operating time for completion of the Nuss procedure was 118 (SD, 51) minutes with less than 10 mL of blood loss in 93% of cases. Modifications to the Nuss procedure were made in 6 cases: adjunctive cartilage resection was completed in 4 patients and pericostal wire stabilization in 2. Average length of hospital stay was 5.8 (±1.3) days. Hospital charges associated with bar placement were $24,796.82 (SD, 6156.43). Bar removal was completed 2.19 years postplacement (SD, 0.61; n = 114) with an average hospital charge of $5442.00 (SD, 3049.46). Bars were removed in 87 minutes (SD, 40), and blood loss stayed less than 10 mL in 75% of cases. Most bar removals were completed as a day surgery procedure (85%) with a length of stay of 0.5 days (SD, 1).
2.3. Complications Early complications related to Lorenz bar placement were reported in 9 patients (7%) and late complications in 29 patients (25%). Twenty-one patients (18% overall) required rehospitalization. Nineteen (16% overall) of these patients required unplanned reoperation. The most common early complications were pneumothorax requiring postprocedure tube thoracostomy (n = 4) and diaphragm laceration (n = 2). The most common late complications were stabilizer dislodgement/fracture (n = 8), flipped Lorenz bar (n = 6), and nonhealing/infected incisions (n = 5). Four patients had Nuss bars removed at other institutions, and thus, late complications could not be assessed in these patients. Complications after bar removal occurred in the early period and were composed of a hemothorax requiring tube thoracostomy and a wound infection. There was one case of recurrence of the pectus excavatum deformity successfully treated with repeated Nuss procedure.
2.4. Pain management descriptors One hundred eight cases (91.5%) were completed using epidural analgesia and 10 (8.5%) using PCA. Six of the 10 PCA patients had either contraindication to an epidural approach or chose against it. The remaining 4 patients had epidurals that did not adequately manage their pain, resulting in an epidural failure rate of 3.6%. Failed epidurals were identified either in the operating room or recovery room, allowing for administration of intravenous opioids during the transition to PCA while in the recovery room. Of the patients receiving PCA, 9 received morphine and 1 received hydromorphone. Among cases completed with epidural analgesia, 80% were thoracic epidurals, 19% were lumbar epidurals, and 1% was indeterminate from the medical record. All epidurals had an opioid component; morphine was used for 44% patients,
1769 hydromorphone was used for 39%, and fentanyl was used for 17%. Bupivicaine (87%) or ropivacaine (13%) were used in 94% of epidurals. Clonidine was used additionally in 20% of epidural formularies. Epidural analgesia was constantly monitored and adjusted to maximize comfort. Adjustments ranged from 0 to 9 per patient with a mean of 1.8 (SD, 1.7; Mdn 1) and included medication changes, rate changes, and epidural boluses. The average length of use for the epidural catheter was 92.0 hours (SD, 22.0; n = 105) with a longer duration in the thoracic vs lumbar location (95 hours SD, 21 vs 30.1 hours SD, 21.9). Intravenous ketorolac was used to augment pain relief in 69% of the epidural patients. This addition occurred within 48 hours postprocedure for 93% of patients. The VNRS pain scores (0-10) for all patients were averaged across 12-hour time blocks. The highest pain scores occurred in the first postoperative shift (3.5; SD, 2.2). Scores decreased by 60 hours postoperatively (2.9; SD, 2.0; P = .06). Initial mean pain scores were less than 4, with 68% of patients reporting a pain score of 4.0 or lower in the first postoperative shift and 80% less than 5.0. These scores suggest that most patients were not in significant pain upon awakening from surgery. Pain scores did not differ as a function of type of opioid used or location of epidural catheter (Ps N .05). Pain scores decreased with the addition of ketorolac in patients with epidural catheters (M pain score in shift before ketorolac 3.70 [SD, 1.75] vs M pain score in shift ketorolac was added 3.33 [SD, 1.84]) but did not reach statistical significance (P = .22). Epidural clonidine was not found to have a significant independent effect on pain scores (ie, shifts 1-5) (Ps N .05). The small size of the PCA group prohibited meaningful comparison to patients receiving epidural analgesia.
3. Discussion This description of surgical outcomes and pain management strategy at the Children's Hospital of Wisconsin upon implementation of the Nuss procedure highlights some important lessons for institutions developing a program. From a patient and surgical perspective, the descriptors show no major variations from other large series [3,7,16,17,32-53]. This series has significant long-term follow-up extending 2 years postbar removal with one recurrence successfully treated with repeat Nuss procedure. The delivery of pain management after the Nuss procedure at this institution uses a dedicated pain service with considerable expertise in epidural analgesia. This expertise resulted in more than 68 cases (108 epidurals total) of excellent pain control (pain scores maintained b4.0 VNRS) with an epidural failure rate of only 3.6% and compares extremely favorably with another large series that reported a tenfold higher failure rate [46]. The
1770 total number of changes made to the epidural pain management plan (drug changes, concentration changes, rate changes, boluses) ranged from 0 to 9, with a mean of 1.8 changes (SD, 1.7). This low number of adjustments supports the success of epidural pain management postNuss procedure. Unlike the 2 randomized controlled trials using fentanylbased epidural regimens, this series used less lipophilic opioids that remained more localized in the epidural space. This diminished the narcotic dosage required for effective analgesia commensurate with a much lower volume of distribution for the drug. The choice of opioid, morphine or hydromorphone, did not affect pain scores in this series. Epidural clonidine and local anesthetic adjuncts, although not significantly impacting pain scores, further lowered narcotic dosing. Interestingly, the site of epidural catheter placement proved to be independent of success of the analgesia. A single retrospective review of lumbar epidural morphine in children undergoing Nuss procedure showed efficacy through the first postoperative day [25]. Similarly, in this experience, lumbar epidural analgesia was effective through 30 hours postoperatively. This duration was likely aided by a more comprehensive epidural pharmacy and the use of epidurals with patient-controlled bolus capability. Thoracic epidurals typically remained 65 hours longer than lumbar epidurals; however, the conversion of lumbar epidurals to other pain modalities was not driven by elevation in pain scores. These conversions in the lumbar epidural group reflect an early bias, which is no longer the practice of the pain service. Ketorolac showed no additional significant benefit in pain scores, but it was used safely as an adjunct intravenous medication. When used for breakthrough pain, ketorolac use was followed by normalization of pain scores in subsequent shifts. In current practice, ketorolac is now used as an adjunct for all patients. Although the commitment of the acute pain service allowed for a very high epidural success rate, it did not allow for a significantly large PCA cohort to draw any meaningful comparisons between epidural and PCA cohorts. A randomized controlled trial with epidural-space contained opioids vs intravenous opioid PCA administration would be enlightening. In summary, the institution of the Nuss procedure provides a highly desired result with complication rates equivalent to those published by other large series. The procedure has been a significant advance in the surgical approach to pectus excavatum. The ideal approach would deliver this result with even lower risk. A pain service-driven epidural administration of morphine or hydromorphone with local anesthetic provides excellent analgesia for patients after Nuss procedure. The success of epidural analgesia appears is independent of catheter site and adjunctive medications. Ketorolac is a useful and safe breakthrough medication in this strategy.
J.C. Densmore et al.
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1771 [38] Boehm RA, Muensterer OJ, Till H. Comparing minimally invasive funnel chest repair versus the conventional technique: an outcome analysis in children. Plast Reconstr Surg 2004;114:668-73 [discussion 74-5]. [39] Bohosiewicz J, Kudela G, Koszutski T. Results of Nuss procedures for the correction of pectus excavatum. Eur J Pediatr Surg 2005;15: 6-10. [40] Cheng YL, Lee SC, Huang TW, et al. Efficacy and safety of modified bilateral thoracoscopy-assisted Nuss procedure in adult patients with pectus excavatum. Eur J Cardiothorac Surg 2008;34:1057-61. [41] Fang FC, Cheng YL, Lee SC, et al. Clinical experience of Nuss procedure for pectus excavatum in adult female patients. Thorac Cardiovasc Surg 2008;56:283-6. [42] Felts E, Jouve JL, Blondel B, et al. Child pectus excavatum: correction by minimally invasive surgery. Orthop Traumatol Surg Res 2009;95: 190-5. [43] Haecker FM, Bielek J, von Schweinitz D. Minimally invasive repair of pectus excavatum (MIRPE)—the Basel experience. Swiss Surg 2003; 9:289-95. [44] Jacobs JP, Quintessenza JA, Morell VO, et al. Minimally invasive endoscopic repair of pectus excavatum. Eur J Cardiothorac Surg 2002; 21:869-73. [45] Kim do H, Hwang JJ, Lee MK, et al. Analysis of the Nuss procedure for pectus excavatum in different age groups. Ann Thorac Surg 2005; 80:1073-7. [46] Miller KA, Woods RK, Sharp RJ, et al. Minimally invasive repair of pectus excavatum: a single institution's experience. Surgery 2001;130: 652-7 [discussion 7-9]. [47] 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. [48] Ohno K, Morotomi Y, Ueda M, et al. Comparison of the Nuss procedure for pectus excavatum by age and uncommon complications. Osaka City Med J 2003;49:71-6. [49] Park HJ, Chung WJ, Lee IS, et al. Mechanism of bar displacement and corresponding bar fixation techniques in minimally invasive repair of pectus excavatum. J Pediatr Surg 2008;43:74-8. [50] 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;77:289-95. [51] Pilegaard HK, Licht PB. Early results following the Nuss operation for pectus excavatum–a single-institution experience of 383 patients. Interact Cardiovasc Thorac Surg 2008;7:54-7. [52] Torre M, Jasonni V, Asquasciati C, et al. Absorbable stabilisation of the bar in minimally invasive repair of pectus excavatum. Eur J Pediatr Surg 2008;18:407-9. [53] Zallen GS, Glick PL. Miniature access pectus excavatum repair: lessons we have learned. J Pediatr Surg 2004;39:685-9.
www.elsevier.com/locate/jpedsurg
Initial surgical and pain management outcomes after Nuss procedure John C. Densmore ⁎, Danielle B. Peterson, Linda L. Stahovic, Michelle L. Czarnecki, Keri R. Hainsworth, Hobart W. Davies, Laura D. Cassidy, Steven J. Weisman, Keith T. Oldham Children's Hospital of Wisconsin, Milwaukee, WI 53226, USA Medical College of Wisconsin, Milwaukee, WI 53226, USA Received 10 December 2009; revised 26 January 2010; accepted 27 January 2010
Key words: Nuss procedure; Minimally invasive repair of pectus excavatum; Outcomes; Pain management; Epidural
Abstract Purpose: The purpose of this article was to report surgical and pain management outcomes of the initial Nuss procedure experience at the Children's Hospital of Wisconsin (Milwaukee) and to place this experience in the context of the published literature. Methods: The initial 118 consecutive Nuss procedures in 117 patients were retrospectively reviewed with approval of the Children's Hospital of Wisconsin human rights review board. Patient, surgical, complication, and pain descriptors were collected for each case. Statistical methods for comparison of pain strategies included the Kolmogorov-Smirnov test for normality, 1-way repeated measures analysis of variance, and paired t tests. Results: Patient, surgical, and complication descriptors were comparable to other large series. Complication rates were 7% early and 25% late. Epidural success rate was 96.4%. There was 1 episode of recurrence 2 years postbar removal (n = 114). Conclusions: The institution of the Nuss procedure provides a highly desired result with significant complication rates. The ideal approach would deliver this result with lower risk. A pain service-driven epidural administration of morphine or hydromorphone with local anesthetic provides excellent analgesia for patients after Nuss procedure. The success of epidural analgesia is independent of catheter site and adjunctive medications. Ketorolac was an effective breakthrough medication. © 2010 Elsevier Inc. All rights reserved.
Pectus excavatum is the most frequent congenital deformity of the anterior chest wall, affecting 0.8% to 0.14% of the population [1,2]. Because of asymmetric ⁎ Corresponding author. Division of Pediatric Surgery, Department of Surgery, Medical College of Wisconsin, Milwaukee, WI 53226, USA. Tel.: +1 414 266 6550; fax: +1 414 266 6579. E-mail address: [email protected] (J.C. Densmore). 0022-3468/$ – see front matter © 2010 Elsevier Inc. All rights reserved. doi:10.1016/j.jpedsurg.2010.01.028
cartilaginous growth, this condition results in a concavity of the precordium with a resultant restrictive pulmonary defect and decreased aerobic capacity when compared to agematched controls [2-5]. The role of surgery in reversal of these defects remains controversial; however, many patients perceive improvement [4,6-12]. Surgical correction has been correlated with positive outcomes and improvement of body image [13,14]. With the demand for minimally invasive
1768 surgical approaches increasing, the surgical repair of pectus excavatum has largely shifted away from the Ravitch repair. Recent innovations have included the use of substernal magnets, vacuum lifters, and the Nuss procedure [15-18]. The Nuss procedure is the most common minimally invasive repair of pectus excavatum and corrects the point of maximal concavity using a thoracoscopically directed transthoracic convex substernal bar. Although patients undergoing the Nuss procedure enjoy a smaller scar, significant postoperative pain results from an instantaneous substernal correction. Successful management of post-Nuss procedure pain is a priority as pain decreases patient satisfaction and increases complication rates [19]. Pain management strategies have included systemic opioids via patient-controlled analgesia (PCA), nonsteroidal antiinflammatory medications, hypnosis, and regional anesthesia (opioid, local anesthetic, and αblockade) [19-27]. Although large series demonstrate that modern pain control strategies are adequate, the optimal technique has yet to be clearly determined [3,27,28]. Two small prospective randomized trials have been completed in children examining the efficacy of morphine or fentanyl PCA vs fentanyl/local anesthetic epidural analgesia. One study demonstrated no significance difference in visual analog pain scores or complication rates between fentanyl PCA and fentanyl/bupivacaine epidural treatment in 28 children [21]. A second study randomized 40 children between morphine PCA and fentanyl/ropivacaine epidural treatment. The results of this study demonstrate lower visual analog pain scores in the epidural group [29]. Given the lipophilic nature of fentanyl and its rapid dissemination into a large volume of distribution, the results of fentanyl epidural catheter treatments do not use the specificity of the epidural space afforded by other opioids. Adult thoracotomy pain studies have shown equivalent pain control with fentanyl treatment independent of site of administration [30]. The purpose of this review was to summarize the initial surgical outcomes and detail the pain management strategy used at the Children's Hospital of Wisconsin (Milwaukee). This experience is useful for other institutions building experience with the Nuss procedure given the significant learning curve described by other groups [27,31-36].
1. Materials and methods After approval from the Children's Hospital of Wisconsin Human Rights Review Board, a retrospective chart review was conducted for patients undergoing the Nuss procedure for pectus excavatum repair at between 1999 and 2004. All consecutive cases of Nuss procedure were included in this interval. Patient data were collected 2 years after removal of the Nuss bar. Using anonymous case numbers, the following data were collected: patient descriptors (age, weight, sex, race, pulmonary function, and Haller index), surgical descriptors (number of bars, use of stabilizers, operative
J.C. Densmore et al. time, estimated blood loss, adjunct cartilage resection, length of stay, and cost), complications (early vs late; b vs N 30 postoperative days), and pain management descriptors (PCA or epidural, epidural level, PCA/epidural formulary, number of pain interventions required, medication changes, use of ketorolac, use of clonidine, and pain scores). A specialized team of pediatric anesthesiologists and an advanced practice nurse forming an acute pain management service delivered comprehensive pain management. Patients were transitioned to oral analgesics before hospital discharge. Nursing staff assessed pain scores using the 0 to 10 verbal numeric rating scale (VNRS; 0 = no pain; 10 = worst imaginable pain). Per guidelines, vital signs, pain, and sedation scores were recorded every 2 to 4 hours. All pain descriptors were collected as timed data points. Available Haller indices were calculated from computed tomographic scans by dividing the widest intrapleural coronal chest diameter by the sagittal distance between the point of maximal concavity and the anterior vertebral column at the same level. Statistics were included to examine sample characteristics. Numerical variables were examined for normality using the Kolmogorov-Smirnov test. One-way repeated measures analysis of variance was used to examine pain scores over time. Numerical variable comparisons (eg, ketorolac and clonidine effects) were examined using a paired-samples t test. Significant results used a P value less than .05 for all analyses. Statistical analysis was completed using SPSS, version 11.5 (SPSS Inc, Chicago, Ill).
2. Results 2.1. Patient descriptors Charts of 117 consecutive patients undergoing 118 Nuss procedures were reviewed. The mean age at Nuss bar placement was 12.9 years (SD, 4.8). Mean weight was 46.7 kg (SD, 17.4). Seventy-five percent of patients were male. The ethnicity of our cohort was 93% white, 3% Hispanic, and 4% “other.” There were no African American, Asian, or American Indian patients. Preoperative pulmonary function tests were completed in 28 patients (24%). These tests demonstrated a forced expiratory volume in 1 second of 89% of predicted (SD, 13), an forced vital capacity of 92% of predicted (SD, 13) and forced expiratory volume in 1 second– forced vital capacity ratio of 0.9 (SD, 0.1). The average Haller index was 4.0 (SD, 1.5; n = 65). Three patients had previous chest surgery, 4 had connective tissue disorders, and 2 patients had ulcerative colitis treated with 6-mercaptopurine.
2.2. Surgical descriptors This patient series was the experience of 9 surgeons, all trained in either pediatric or pediatric cardiothoracic
Management outcomes after Nuss procedure surgery. Most patients required a single bar (93%) and bilateral stabilizer placement (70%). A mean of 2.75 stabilizers was used in patients requiring 2 bars for repair. Operating time for completion of the Nuss procedure was 118 (SD, 51) minutes with less than 10 mL of blood loss in 93% of cases. Modifications to the Nuss procedure were made in 6 cases: adjunctive cartilage resection was completed in 4 patients and pericostal wire stabilization in 2. Average length of hospital stay was 5.8 (±1.3) days. Hospital charges associated with bar placement were $24,796.82 (SD, 6156.43). Bar removal was completed 2.19 years postplacement (SD, 0.61; n = 114) with an average hospital charge of $5442.00 (SD, 3049.46). Bars were removed in 87 minutes (SD, 40), and blood loss stayed less than 10 mL in 75% of cases. Most bar removals were completed as a day surgery procedure (85%) with a length of stay of 0.5 days (SD, 1).
2.3. Complications Early complications related to Lorenz bar placement were reported in 9 patients (7%) and late complications in 29 patients (25%). Twenty-one patients (18% overall) required rehospitalization. Nineteen (16% overall) of these patients required unplanned reoperation. The most common early complications were pneumothorax requiring postprocedure tube thoracostomy (n = 4) and diaphragm laceration (n = 2). The most common late complications were stabilizer dislodgement/fracture (n = 8), flipped Lorenz bar (n = 6), and nonhealing/infected incisions (n = 5). Four patients had Nuss bars removed at other institutions, and thus, late complications could not be assessed in these patients. Complications after bar removal occurred in the early period and were composed of a hemothorax requiring tube thoracostomy and a wound infection. There was one case of recurrence of the pectus excavatum deformity successfully treated with repeated Nuss procedure.
2.4. Pain management descriptors One hundred eight cases (91.5%) were completed using epidural analgesia and 10 (8.5%) using PCA. Six of the 10 PCA patients had either contraindication to an epidural approach or chose against it. The remaining 4 patients had epidurals that did not adequately manage their pain, resulting in an epidural failure rate of 3.6%. Failed epidurals were identified either in the operating room or recovery room, allowing for administration of intravenous opioids during the transition to PCA while in the recovery room. Of the patients receiving PCA, 9 received morphine and 1 received hydromorphone. Among cases completed with epidural analgesia, 80% were thoracic epidurals, 19% were lumbar epidurals, and 1% was indeterminate from the medical record. All epidurals had an opioid component; morphine was used for 44% patients,
1769 hydromorphone was used for 39%, and fentanyl was used for 17%. Bupivicaine (87%) or ropivacaine (13%) were used in 94% of epidurals. Clonidine was used additionally in 20% of epidural formularies. Epidural analgesia was constantly monitored and adjusted to maximize comfort. Adjustments ranged from 0 to 9 per patient with a mean of 1.8 (SD, 1.7; Mdn 1) and included medication changes, rate changes, and epidural boluses. The average length of use for the epidural catheter was 92.0 hours (SD, 22.0; n = 105) with a longer duration in the thoracic vs lumbar location (95 hours SD, 21 vs 30.1 hours SD, 21.9). Intravenous ketorolac was used to augment pain relief in 69% of the epidural patients. This addition occurred within 48 hours postprocedure for 93% of patients. The VNRS pain scores (0-10) for all patients were averaged across 12-hour time blocks. The highest pain scores occurred in the first postoperative shift (3.5; SD, 2.2). Scores decreased by 60 hours postoperatively (2.9; SD, 2.0; P = .06). Initial mean pain scores were less than 4, with 68% of patients reporting a pain score of 4.0 or lower in the first postoperative shift and 80% less than 5.0. These scores suggest that most patients were not in significant pain upon awakening from surgery. Pain scores did not differ as a function of type of opioid used or location of epidural catheter (Ps N .05). Pain scores decreased with the addition of ketorolac in patients with epidural catheters (M pain score in shift before ketorolac 3.70 [SD, 1.75] vs M pain score in shift ketorolac was added 3.33 [SD, 1.84]) but did not reach statistical significance (P = .22). Epidural clonidine was not found to have a significant independent effect on pain scores (ie, shifts 1-5) (Ps N .05). The small size of the PCA group prohibited meaningful comparison to patients receiving epidural analgesia.
3. Discussion This description of surgical outcomes and pain management strategy at the Children's Hospital of Wisconsin upon implementation of the Nuss procedure highlights some important lessons for institutions developing a program. From a patient and surgical perspective, the descriptors show no major variations from other large series [3,7,16,17,32-53]. This series has significant long-term follow-up extending 2 years postbar removal with one recurrence successfully treated with repeat Nuss procedure. The delivery of pain management after the Nuss procedure at this institution uses a dedicated pain service with considerable expertise in epidural analgesia. This expertise resulted in more than 68 cases (108 epidurals total) of excellent pain control (pain scores maintained b4.0 VNRS) with an epidural failure rate of only 3.6% and compares extremely favorably with another large series that reported a tenfold higher failure rate [46]. The
1770 total number of changes made to the epidural pain management plan (drug changes, concentration changes, rate changes, boluses) ranged from 0 to 9, with a mean of 1.8 changes (SD, 1.7). This low number of adjustments supports the success of epidural pain management postNuss procedure. Unlike the 2 randomized controlled trials using fentanylbased epidural regimens, this series used less lipophilic opioids that remained more localized in the epidural space. This diminished the narcotic dosage required for effective analgesia commensurate with a much lower volume of distribution for the drug. The choice of opioid, morphine or hydromorphone, did not affect pain scores in this series. Epidural clonidine and local anesthetic adjuncts, although not significantly impacting pain scores, further lowered narcotic dosing. Interestingly, the site of epidural catheter placement proved to be independent of success of the analgesia. A single retrospective review of lumbar epidural morphine in children undergoing Nuss procedure showed efficacy through the first postoperative day [25]. Similarly, in this experience, lumbar epidural analgesia was effective through 30 hours postoperatively. This duration was likely aided by a more comprehensive epidural pharmacy and the use of epidurals with patient-controlled bolus capability. Thoracic epidurals typically remained 65 hours longer than lumbar epidurals; however, the conversion of lumbar epidurals to other pain modalities was not driven by elevation in pain scores. These conversions in the lumbar epidural group reflect an early bias, which is no longer the practice of the pain service. Ketorolac showed no additional significant benefit in pain scores, but it was used safely as an adjunct intravenous medication. When used for breakthrough pain, ketorolac use was followed by normalization of pain scores in subsequent shifts. In current practice, ketorolac is now used as an adjunct for all patients. Although the commitment of the acute pain service allowed for a very high epidural success rate, it did not allow for a significantly large PCA cohort to draw any meaningful comparisons between epidural and PCA cohorts. A randomized controlled trial with epidural-space contained opioids vs intravenous opioid PCA administration would be enlightening. In summary, the institution of the Nuss procedure provides a highly desired result with complication rates equivalent to those published by other large series. The procedure has been a significant advance in the surgical approach to pectus excavatum. The ideal approach would deliver this result with even lower risk. A pain service-driven epidural administration of morphine or hydromorphone with local anesthetic provides excellent analgesia for patients after Nuss procedure. The success of epidural analgesia appears is independent of catheter site and adjunctive medications. Ketorolac is a useful and safe breakthrough medication in this strategy.
J.C. Densmore et al.
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