- Email: [email protected]
Is it necessary to drain all postoperative fluid collections after appendectomy for perforated appendicitis?
Journal of Pediatric Surgery (2011) 46, 1126–1130
www.elsevier.com/locate/jpedsurg
Is it necessary to drain all postoperative fluid collections after appendectomy for perforated appendicitis? Hannah G. Piper a,⁎, Betul Derinkuyu b , Korgun Koral b , Eduardo A. Perez a , Joseph T. Murphy a a
Department of Surgery, Children's Medical Center Dallas, University of Texas Southwestern Medical Center, Dallas, Tex Department of Radiology, Children's Medical Center Dallas, University of Texas Southwestern Medical Center, Dallas, Tex
b
Received 8 March 2011; accepted 26 March 2011
Key words: Perforated appendicitis; Postoperative fluid; Percutaneous drainage
Abstract Purpose: Children treated for perforated appendicitis can have significant morbidity. Management often includes looking for and draining postoperative fluid collections. We sought to determine if drainage hastens recovery. Methods: Children with perforated appendicitis treated with appendectomy from 2006 to 2009 were reviewed. Patients with postoperative fluid that was drained were compared with patients with undrained fluid with regard to preoperative features and postoperative outcomes. Statistical analyses included paired Student's t tests, Mann-Whitney U test, and linear regression. Results: Five hundred ninety-one patients were reviewed. Seventy-one patients had postoperative fluid, of whom 36 had a drainage procedure and 35 did not. There was no significant difference in white blood cell count at the time of assessment for drainage (16.4 ± 4.0 vs 14.6 ± 4.9, P = .14), days with fever (3.5 ± 3.0 vs 2.9 ± 2.5, P = .35), or readmission rate (19% vs 31%, P = .28). After multivariate linear regression, larger fluid volumes were associated with prolonged length of stay (LOS) (P = .03). For fluid collections between 30-100 mL, there was no significant difference in LOS between the drain and nodrain groups (9.8 ± 3.5 vs 10.9 ± 5.2 days, P = .51). Conclusion: After appendectomy for perforated appendicitis, larger postoperative fluid collections are associated with prolonged LOS. Drainage of collections less than 100 mL may not hasten recovery. © 2011 Elsevier Inc. All rights reserved.
Appendicitis remains the most common indication for abdominal surgery in the pediatric population, with the annual incidence in the United States estimated to be 25 per 10,000 children between the ages of 10 ands 17 years and 1.5 per 10,000 children younger than of 4 years [1]. Most of these patients have simple appendicitis with a brief hospital ⁎ Corresponding author. Division of Pediatric Surgery, The Hospital for Sick Children, Toronto, Ontario, Canada M5G IX8. Tel.: +1 647 801 6703. E-mail address: [email protected] (H.G. Piper). 0022-3468/$ – see front matter © 2011 Elsevier Inc. All rights reserved. doi:10.1016/j.jpedsurg.2011.03.043
stay. However, approximately 20% to 35% of patients will have perforated appendicitis [2,3] that sometimes dictates a prolonged hospitalization and further interventions. Children with persistent fever, leukocytosis, and/or anorexia in the postoperative period will often undergo imaging such as ultrasound or computed tomography (CT) to identify an intraperitoneal abscess thought to be the source of the ongoing inflammatory response. However, with increased imaging availability and sophistication, there is a higher likelihood of detecting nonpurulent fluid collections that
Draining postoperative fluid collections after appendectomy may or may not be causing any symptoms [4,5]. One of the recent challenges in the management of complicated appendicitis is deciding whether percutaneously draining these fluid collections will have clinical benefit beyond treatment with antibiotics alone. There have been several recent studies suggesting that children will recover fully with only antibiotics in most cases [6-9]. The purpose of this study is to determine whether drainage of postoperative fluid collections hastens recovery in children after surgery for perforated appendicitis and whether drains should be placed routinely, in select cases or not at all.
1. Methods All patients younger than 19 years with appendicitis treated with appendectomy between March 2006 and March 2009 at the Children's Medical Center, Dallas, TX, were retrospectively reviewed after evaluation and approval by the University of Texas Southwestern Medical Center Institutional Review Board. Only children with perforated appendicitis based on both pathologic diagnosis and the surgeon's diagnosis at the time of operation were included in the analysis. Children who presented with perforated appendicitis with associated abscess who did not undergo appendectomy on the initial admission were excluded. Patients with perforated appendicitis who then had postoperative imaging (CT scan) owing to clinical factors including leukocytosis, fever, diarrhea, poor oral intake, or ongoing abdominal pain and in whom a fluid collection was identified on CT were specifically reviewed. Within this group, children who had a percutaneous drain placed by radiology were compared with those children who did not. If a drain was placed, it was left in situ until the drainage was minimal (b10 mL/d). None of the children were sent home with a drain. All of the patients were treated with intravenous ampicillin/sulbactam or gentamicin (if penicillin allergic) and metronidazole from the time of surgery until discharge.
Table 1
1127 Some patients were continued on oral amoxicillin/clavulanate and metronidazole after discharge, depending on surgeon preference. The drain and no-drain groups were compared in several variables including age, sex, findings on preoperative and postoperative imaging, number of days with fever, white blood cell count (WBC) on the day of postoperative CT, days to regular diet, length of stay (LOS), duration of treatment with antibiotics, and any postoperative complications. The volume of all fluid collections was measured on CT with a Vitrea work station (Vital Images, Minnetonka, MN) by isolating regions of interest in each slice and multiplying the area by the thickness for the entire collection. Statistical analyses were performed with the paired Student's t test for normally distributed data and the Mann-Whitney U test for nonparametric comparisons. Analysis of variance and Kruskal-Wallis tests were used for comparisons of more than 2 variables. Univariate and multivariate linear regressions were also performed. P b .05 was considered statistically significant. All analyses were performed with the SPSS Statistical Package version 17.0 (SPSS Inc, Chicago, IL).
2. Results Between March 2006 and March 2009, a total of 1844 appendectomies were performed at the Children's Medical Center, Dallas, TX. Among this group, 591 children (32%) had perforated appendicitis. Seventy-six of the patients (13%) with perforated appendicitis went on to have a postoperative CT scan. The decision to obtain a CT scan was made by the patient's surgeon based on persistent fever, leukocytosis, inability to tolerate diet, or other symptoms including ongoing abdominal pain or diarrhea. If fluid was seen on the CT, the patient was then evaluated for possible percutaneous drain placement. Thirty-six of the 76 patients evaluated had fluid collections that were drained percutaneously (drain), 35 patients had fluid collections that were not
Patient characteristics (N = 71)
Age (y) Male:female (%) Preoperative CT scan obtained (%) Postoperative day CT performed (d) WBC on the day of CT (×103) Postoperative days with fever (N38.0) (d) Time to regular diet (d) Volume of postoperative fluid collection (mL) LOS (d) Duration of antibiotics (d) No. of readmissions No. of postoperative bowel obstructions Values reported as mean with SD.
Drain (36)
No drain (35)
P
8.4 (±3.4) 54:36 64 6 (±1) 16.4 (±4.0) 3.5 (± 3.0) 6.3 (±4.1) 148.7 (±133.3) 12.1 (±5.7) 18.9 (±3.8) 7 (19%) 4 (11%)
9.5 (±4.4) 53:37 55 7 (±2) 14.6 (±4.9) 2.9 (±2.5) 5.0 (±2.7) 45.2 (±76.6) 8.5 (±4.5) 15.3 (±5.6) 11 (31%) 2 (6%)
.27 .93 .57 .15 .14 .35 .11 .00016 .004 .002 .28 .42
1128
H.G. Piper et al.
Table 2 Clinical factors and the association with length of hospital stay Variable
P
95% CI
Procedure (drain vs no drain) Volume of collection (mL) WBC (×103) Age (y)
.29 .03 .4 .09
−1.3-4.4 0.001-0.02 −0.18-0.42 0.66-0.5
Volume of the collection was found to have a statistically significant correlation with LOS. CI indicates confidence interval.
drained (no drain), and 5 patients did not have an appreciable fluid collection and were excluded from further analysis. None of the patients underwent operative drainage. Both the drain and no-drain groups had similar clinical characteristics before evaluation for drain placement (Table 1). There was no significant difference between the 2 groups with regard to the number of days of postoperative fever, time to tolerance of regular diet, or WBC at the time of postoperative CT scan. In addition, there was no a significant difference in the timing of the CT scan for those who received a drain vs those who did not. Patients who received a drain did, however, have larger fluid collections on average compared with patients who did not. Patients with drains also stayed in the hospital significantly longer (12.1 ± 5.7 days vs 8.4 ± 4.5 days, P = .004) and had more days of antibiotics (18.9 ± 3.8 days vs 15.3 ± 5.6 days) (Table 1). Fluid was sent for culture from all patients who had a drainage procedure. Of the 36 children, 13 (37%) had positive cultures; in all cases, the bacteria were gram negative and in no case did these data alter the type of antibiotic administered. The volume of the fluid collection identified on CT was the only variable found to be associated with a prolonged hospital stay by both univariate and multivariate analyses (Table 2). Larger fluid collections were also found to predict a longer febrile period. A fluid collection greater than 100 mL was associated with a LOS of 13.4 ± 1.1 days and fever for 4.8 ± 0.6 days, whereas children with collections 100 mL or less stayed in the hospital for an average of 10.3 ± 1.1 days (P = .001) and were febrile for an average of 3.3 ± 0.8 days (P = .02) (Table 3). The drainage procedure itself did not seem to have a statistically significant association with LOS independent of fluid
Table 3 Clinical course based on volume of postoperative fluid collection
Table 4
Volume of fluid collections within treatment groups
Volume (mL) b30 30-100 N100
Procedure
Total
Drain
No drain
3 15 18
20 12 3
23 27 21
Number of patients within the drain and no-drain groups with collections less than 30 mL, 30 to 100 mL, and greater than 100mL.
collection volume. This was most evident for patients with fluid collections between 30 and 100 mL in size of whom there were 15 patients who got drains and 12 patients who did not (Tables 4 and 5). Seven patients (19%) in the drain group were readmitted after discharge compared with 11 patients (31%) in the no-drain group, and this was not significantly different (P = .28). None of the patients in the no-drain group who were readmitted required drainage of an intraabdominal fluid collection. The most common complication requiring readmission was postoperative bowel obstruction of which there were 4 (11%) vs 2 (6%) in the drain and no-drain groups, respectively.
3. Discussion Despite that appendicitis is very common, the management of children with complicated appendicitis has not been standardized. Often, there is variance among institutions with regard to duration and route of antibiotics, monitoring laboratory parameters, and postoperative imaging [10]. Part of the difficulty in establishing strict management protocols and guidelines for this patient population is that the course of the disease is quite different among children. Some children will have widespread infection throughout the abdominal cavity and yet will recover quickly, whereas others with minimal abdominal contamination remain febrile and fail to regain their appetite for an unexpected number of days. In fact, many of the factors that we tend to attribute with a more severe infection have not been shown to correlate with developing a postoperative abscess, including duration of symptoms before presentation, duration of fever, or elevated Table 5 Average LOS for each treatment group based on volume of collection
Volume of LOS (d) collection (mL)
Postoperative WBC on postoperative day fever (no. of days) 7 (×103)
Volume (mL)
Procedure
LOS (d)
P
N30
1.9 ± 0.4 3.3 ± 0.8 4.8 ± 0.6 .02
30-100
8.3 (±3.8) 6.9 (±3.8) 9.8 (±3.5) 10.9 (±5.2) 14.8 (±6.5) 8.7 (±1.5)
.56
b30 30-99 N 100 P
Drain No drain Drain No drain Drain No drain
6.7 ± 0.8 10.3 ± 1.1 13.4 ± 1.1 b.001
Values reported as mean with SD.
14.2 ± 1.2 16.0 ± 0.9 16.7 ± 1.0 .2
N100
Length of stay reported as mean and SD.
.51 .13
Draining postoperative fluid collections after appendectomy WBC [2]. Because of this, it can be difficult to predict who should be investigated for postoperative intraabdominal fluid collections and who will require intervention. Furthermore, the question of whether draining these collections improve outcome becomes important because, if not, the decision to investigate is less relevant. We have demonstrated in this study that when comparing the most common criteria upon which we base discharge from the hospital (fever, WBC, tolerance of regular diet), there was no significant difference between patients who had their postoperative fluid collections drained and those who did not. Likewise, there was no predictable way to identify patients with large collections greater than 100 mL based on symptoms alone. This suggests that the fluid collection may not be the sole source of symptoms and that a full recovery may not be dependent on drainage in all cases. Our findings correlate with several smaller studies that suggest that most patients with postoperative collections can be managed by antibiotics alone. In a study by Okoye et al [6], 23 children investigated after appendectomy were found to have abdominal collections, 21 (91%) of whom recovered with antibiotics alone after an average of 8.3 days. Similarly, in a study by Forgues et al [8], 22 (85%) of 26 patients with postoperative fluid collections were successfully treated with antibiotics alone for an average of 8 days with resolution of symptoms. Although neither study defined what constituted a treatment failure, both concluded that most children improve without drainage. However, the question that was not answered is whether these patients would have improved more quickly had drains been placed. Our study addresses the efficacy of drain placement by comparing the LOS between patients who received drains and those who did not. Although LOS is not a direct measure of recovery, children must meet certain clinical criteria before discharge; and therefore, LOS correlates with recovery time. What we found was that the placement of a drain did not itself significantly impact LOS but that the size of collection did. One weakness of this study is that the patients who received drains, on average, had larger fluid collections than those who did not; and therefore, it is difficult to conclude that the patients with large collections greater than 100 mL would have recovered as quickly had they not received drains because there were only 3 such patients in the no-drain group compared with 18 in the drain group. However, there were nearly equal numbers of children with medium-sized collections (30-100 mL) in both the drain and no-drain groups (15 and 12 patients, respectively); and the average LOS between these children did not differ significantly. Therefore, we can conclude that, for patients with collections less than 100 mL, drainage does not appear to hasten recovery. Whether this remains true for larger collections requires a prospective study to determine. Given that there are likely some children with postoperative fluid collections who will not benefit from drain placement, it is important to consider the potential risks associated with the procedure. Although it does require a high level of subspecialty training, percutaneous drain placement via either the transrectal
1129 or transabdominal route is a relatively safe procedure. A recent study reported a series of 27 children who had transrectal drains placed without any complications [11]. However, there are also reports of complications from percutaneous drain placement, including bowel perforations and hemorrhage [12,13]. In addition, the procedure often requires sedation and, occasionally, general anesthesia using a significant amount of resources. Given these potential risks, it is important to identify which patients benefit from fluid drainage. It can also be argued from this study that we should be more stringent with postoperative imaging. Given that, at postoperative day 6 or 7, the time when most of our patients were imaged, there was no significant difference in the symptoms between children with large vs small collections, it would be prudent to delay imaging for children who are stable but not yet ready for discharge. Those who subsequently improve can be discharged, and those who do not can then be imaged. In some cases, it is not clear whether a postoperative fluid collection itself is problematic or whether it is merely a marker of inflammation and ongoing acute reaction. Interestingly, only 37% of patients who had fluid sampled had positive bacterial cultures; and this did not correlate with the size of the collection. We did find that children with fluid collections greater than 100 mL took longer to defervesce and stayed in the hospital longer. Similarly, in the adult literature, there is evidence to suggest that larger fluid collections, based on the diameter seen on imaging, are less likely to be treated successfully with antibiotics alone [14,15]. Again, given our small numbers, it is difficult to draw conclusions about the benefit of drainage in this specific group of patients; however, for patients with smaller collections, drainage did not seem to shorten the recovery period. Although not specifically evaluated in this study, there are likely subsets of patients who would benefit from drainage of a postoperative fluid collection. For example, some patients develop collections adjacent to the rectum and bladder and experience symptoms such as dysuria, diarrhea, and/or persistent abdominal or pelvic pain. One could surmise that based on the location of the collection, drainage would help to relieve these symptoms. This remains to be formally studied. In addition, there are likely patients who have true abscesses that are not well treated with antibiotics alone, similar to patients presenting with perforated appendicitis who have drains placed followed by interval appendectomy. Given the preliminary data from this study and the potential for reducing patient care costs and morbidity, a prospective study would be beneficial to determine if patients with large fluid collections greater than 100 mL benefit from percutaneous drainage.
References [1] Rothrock SG, Pagane J. Acute appendicitis in children: emergency department diagnosis and management. Ann Emerg Med 2000;36(1): 39-51.
1130 [2] Henry MC, Walker A, Silverman BL, et al. Risk factors for the development of abdominal abscess following operation for perforated appendicitis in children: a multicenter case-control study. Arch Surg 2007;142(3):236-41 [discussion 241]. [3] Lee JH, Park YS, Choi JS. The epidemiology of appendicitis and appendectomy in South Korea: national registry data. J Epidemiol 2010;20(2):97-105. [4] Serour F, Herman A, Witzling M, et al. Sonographic findings following appendectomy for uncomplicated appendicitis in children. Pediatr Radiol 2009;39(9):926-32. [5] Aveline B, Guimaraes R, Bely N, et al. Intraabdominal serous fluid collections after appendectomy: a normal sonographic finding. AJR Am J Roentgenol 1993;161(1):71-3. [6] Okoye BO, Rampersad B, Marantos A, et al. Abscess after appendicectomy in children: the role of conservative management. Br J Surg 1998;85(8):1111-3. [7] Gorenstein A, Gewurtz G, Serour F, et al. Postappendectomy intraabdominal abscess: a therapeutic approach. Arch Dis Child 1994;70 (5):400-2. [8] Forgues D, Habbig S, Diallo AF, et al. Post-appendectomy intraabdominal abscesses—can they successfully be managed with the sole use of antibiotic therapy? Eur J Pediatr Surg 2007;17(2):104-9.
H.G. Piper et al. [9] Heloury Y, Baron M, Bourgoin S, et al. Medical treatment of postappendectomy intraperitoneal abscesses in children. Eur J Pediatr Surg 1995;5(3):149-51. [10] Chen C, Botelho C, Cooper A, et al. Current practice patterns in the treatment of perforated appendicitis in children. J Am Coll Surg 2003;196(2):212-21. [11] Koral K, Derinkuyu B, Gargan L, et al. Transrectal ultrasound and fluoroscopy-guided drainage of deep pelvic collections in children. J Pediatr Surg 2010;45(3):513-8. [12] Buckley BT, Goodwin M, Boardman P, et al. Percutaneous abscess drainage in the UK: a national survey and single centre study. Clin Radiol 2006;61(1):55-64 [discussion 53-4]. [13] Keckler SJ, Tsao K, Sharp SW, et al. Resource utilization and outcomes from percutaneous drainage and interval appendectomy for perforated appendicitis with abscess. J Pediatr Surg 2008;43(6): 977-80. [14] Kumar RR, Kim JT, Haukoos JS, et al. Factors affecting the successful management of intra-abdominal abscesses with antibiotics and the need for percutaneous drainage. Dis Colon Rectum 2006;49(2):183-9. [15] Bamberger DM. Outcome of medical treatment of bacterial abscesses without therapeutic drainage: review of cases reported in the literature. Clin Infect Dis 1996;23(3):592-603.
www.elsevier.com/locate/jpedsurg
Is it necessary to drain all postoperative fluid collections after appendectomy for perforated appendicitis? Hannah G. Piper a,⁎, Betul Derinkuyu b , Korgun Koral b , Eduardo A. Perez a , Joseph T. Murphy a a
Department of Surgery, Children's Medical Center Dallas, University of Texas Southwestern Medical Center, Dallas, Tex Department of Radiology, Children's Medical Center Dallas, University of Texas Southwestern Medical Center, Dallas, Tex
b
Received 8 March 2011; accepted 26 March 2011
Key words: Perforated appendicitis; Postoperative fluid; Percutaneous drainage
Abstract Purpose: Children treated for perforated appendicitis can have significant morbidity. Management often includes looking for and draining postoperative fluid collections. We sought to determine if drainage hastens recovery. Methods: Children with perforated appendicitis treated with appendectomy from 2006 to 2009 were reviewed. Patients with postoperative fluid that was drained were compared with patients with undrained fluid with regard to preoperative features and postoperative outcomes. Statistical analyses included paired Student's t tests, Mann-Whitney U test, and linear regression. Results: Five hundred ninety-one patients were reviewed. Seventy-one patients had postoperative fluid, of whom 36 had a drainage procedure and 35 did not. There was no significant difference in white blood cell count at the time of assessment for drainage (16.4 ± 4.0 vs 14.6 ± 4.9, P = .14), days with fever (3.5 ± 3.0 vs 2.9 ± 2.5, P = .35), or readmission rate (19% vs 31%, P = .28). After multivariate linear regression, larger fluid volumes were associated with prolonged length of stay (LOS) (P = .03). For fluid collections between 30-100 mL, there was no significant difference in LOS between the drain and nodrain groups (9.8 ± 3.5 vs 10.9 ± 5.2 days, P = .51). Conclusion: After appendectomy for perforated appendicitis, larger postoperative fluid collections are associated with prolonged LOS. Drainage of collections less than 100 mL may not hasten recovery. © 2011 Elsevier Inc. All rights reserved.
Appendicitis remains the most common indication for abdominal surgery in the pediatric population, with the annual incidence in the United States estimated to be 25 per 10,000 children between the ages of 10 ands 17 years and 1.5 per 10,000 children younger than of 4 years [1]. Most of these patients have simple appendicitis with a brief hospital ⁎ Corresponding author. Division of Pediatric Surgery, The Hospital for Sick Children, Toronto, Ontario, Canada M5G IX8. Tel.: +1 647 801 6703. E-mail address: [email protected] (H.G. Piper). 0022-3468/$ – see front matter © 2011 Elsevier Inc. All rights reserved. doi:10.1016/j.jpedsurg.2011.03.043
stay. However, approximately 20% to 35% of patients will have perforated appendicitis [2,3] that sometimes dictates a prolonged hospitalization and further interventions. Children with persistent fever, leukocytosis, and/or anorexia in the postoperative period will often undergo imaging such as ultrasound or computed tomography (CT) to identify an intraperitoneal abscess thought to be the source of the ongoing inflammatory response. However, with increased imaging availability and sophistication, there is a higher likelihood of detecting nonpurulent fluid collections that
Draining postoperative fluid collections after appendectomy may or may not be causing any symptoms [4,5]. One of the recent challenges in the management of complicated appendicitis is deciding whether percutaneously draining these fluid collections will have clinical benefit beyond treatment with antibiotics alone. There have been several recent studies suggesting that children will recover fully with only antibiotics in most cases [6-9]. The purpose of this study is to determine whether drainage of postoperative fluid collections hastens recovery in children after surgery for perforated appendicitis and whether drains should be placed routinely, in select cases or not at all.
1. Methods All patients younger than 19 years with appendicitis treated with appendectomy between March 2006 and March 2009 at the Children's Medical Center, Dallas, TX, were retrospectively reviewed after evaluation and approval by the University of Texas Southwestern Medical Center Institutional Review Board. Only children with perforated appendicitis based on both pathologic diagnosis and the surgeon's diagnosis at the time of operation were included in the analysis. Children who presented with perforated appendicitis with associated abscess who did not undergo appendectomy on the initial admission were excluded. Patients with perforated appendicitis who then had postoperative imaging (CT scan) owing to clinical factors including leukocytosis, fever, diarrhea, poor oral intake, or ongoing abdominal pain and in whom a fluid collection was identified on CT were specifically reviewed. Within this group, children who had a percutaneous drain placed by radiology were compared with those children who did not. If a drain was placed, it was left in situ until the drainage was minimal (b10 mL/d). None of the children were sent home with a drain. All of the patients were treated with intravenous ampicillin/sulbactam or gentamicin (if penicillin allergic) and metronidazole from the time of surgery until discharge.
Table 1
1127 Some patients were continued on oral amoxicillin/clavulanate and metronidazole after discharge, depending on surgeon preference. The drain and no-drain groups were compared in several variables including age, sex, findings on preoperative and postoperative imaging, number of days with fever, white blood cell count (WBC) on the day of postoperative CT, days to regular diet, length of stay (LOS), duration of treatment with antibiotics, and any postoperative complications. The volume of all fluid collections was measured on CT with a Vitrea work station (Vital Images, Minnetonka, MN) by isolating regions of interest in each slice and multiplying the area by the thickness for the entire collection. Statistical analyses were performed with the paired Student's t test for normally distributed data and the Mann-Whitney U test for nonparametric comparisons. Analysis of variance and Kruskal-Wallis tests were used for comparisons of more than 2 variables. Univariate and multivariate linear regressions were also performed. P b .05 was considered statistically significant. All analyses were performed with the SPSS Statistical Package version 17.0 (SPSS Inc, Chicago, IL).
2. Results Between March 2006 and March 2009, a total of 1844 appendectomies were performed at the Children's Medical Center, Dallas, TX. Among this group, 591 children (32%) had perforated appendicitis. Seventy-six of the patients (13%) with perforated appendicitis went on to have a postoperative CT scan. The decision to obtain a CT scan was made by the patient's surgeon based on persistent fever, leukocytosis, inability to tolerate diet, or other symptoms including ongoing abdominal pain or diarrhea. If fluid was seen on the CT, the patient was then evaluated for possible percutaneous drain placement. Thirty-six of the 76 patients evaluated had fluid collections that were drained percutaneously (drain), 35 patients had fluid collections that were not
Patient characteristics (N = 71)
Age (y) Male:female (%) Preoperative CT scan obtained (%) Postoperative day CT performed (d) WBC on the day of CT (×103) Postoperative days with fever (N38.0) (d) Time to regular diet (d) Volume of postoperative fluid collection (mL) LOS (d) Duration of antibiotics (d) No. of readmissions No. of postoperative bowel obstructions Values reported as mean with SD.
Drain (36)
No drain (35)
P
8.4 (±3.4) 54:36 64 6 (±1) 16.4 (±4.0) 3.5 (± 3.0) 6.3 (±4.1) 148.7 (±133.3) 12.1 (±5.7) 18.9 (±3.8) 7 (19%) 4 (11%)
9.5 (±4.4) 53:37 55 7 (±2) 14.6 (±4.9) 2.9 (±2.5) 5.0 (±2.7) 45.2 (±76.6) 8.5 (±4.5) 15.3 (±5.6) 11 (31%) 2 (6%)
.27 .93 .57 .15 .14 .35 .11 .00016 .004 .002 .28 .42
1128
H.G. Piper et al.
Table 2 Clinical factors and the association with length of hospital stay Variable
P
95% CI
Procedure (drain vs no drain) Volume of collection (mL) WBC (×103) Age (y)
.29 .03 .4 .09
−1.3-4.4 0.001-0.02 −0.18-0.42 0.66-0.5
Volume of the collection was found to have a statistically significant correlation with LOS. CI indicates confidence interval.
drained (no drain), and 5 patients did not have an appreciable fluid collection and were excluded from further analysis. None of the patients underwent operative drainage. Both the drain and no-drain groups had similar clinical characteristics before evaluation for drain placement (Table 1). There was no significant difference between the 2 groups with regard to the number of days of postoperative fever, time to tolerance of regular diet, or WBC at the time of postoperative CT scan. In addition, there was no a significant difference in the timing of the CT scan for those who received a drain vs those who did not. Patients who received a drain did, however, have larger fluid collections on average compared with patients who did not. Patients with drains also stayed in the hospital significantly longer (12.1 ± 5.7 days vs 8.4 ± 4.5 days, P = .004) and had more days of antibiotics (18.9 ± 3.8 days vs 15.3 ± 5.6 days) (Table 1). Fluid was sent for culture from all patients who had a drainage procedure. Of the 36 children, 13 (37%) had positive cultures; in all cases, the bacteria were gram negative and in no case did these data alter the type of antibiotic administered. The volume of the fluid collection identified on CT was the only variable found to be associated with a prolonged hospital stay by both univariate and multivariate analyses (Table 2). Larger fluid collections were also found to predict a longer febrile period. A fluid collection greater than 100 mL was associated with a LOS of 13.4 ± 1.1 days and fever for 4.8 ± 0.6 days, whereas children with collections 100 mL or less stayed in the hospital for an average of 10.3 ± 1.1 days (P = .001) and were febrile for an average of 3.3 ± 0.8 days (P = .02) (Table 3). The drainage procedure itself did not seem to have a statistically significant association with LOS independent of fluid
Table 3 Clinical course based on volume of postoperative fluid collection
Table 4
Volume of fluid collections within treatment groups
Volume (mL) b30 30-100 N100
Procedure
Total
Drain
No drain
3 15 18
20 12 3
23 27 21
Number of patients within the drain and no-drain groups with collections less than 30 mL, 30 to 100 mL, and greater than 100mL.
collection volume. This was most evident for patients with fluid collections between 30 and 100 mL in size of whom there were 15 patients who got drains and 12 patients who did not (Tables 4 and 5). Seven patients (19%) in the drain group were readmitted after discharge compared with 11 patients (31%) in the no-drain group, and this was not significantly different (P = .28). None of the patients in the no-drain group who were readmitted required drainage of an intraabdominal fluid collection. The most common complication requiring readmission was postoperative bowel obstruction of which there were 4 (11%) vs 2 (6%) in the drain and no-drain groups, respectively.
3. Discussion Despite that appendicitis is very common, the management of children with complicated appendicitis has not been standardized. Often, there is variance among institutions with regard to duration and route of antibiotics, monitoring laboratory parameters, and postoperative imaging [10]. Part of the difficulty in establishing strict management protocols and guidelines for this patient population is that the course of the disease is quite different among children. Some children will have widespread infection throughout the abdominal cavity and yet will recover quickly, whereas others with minimal abdominal contamination remain febrile and fail to regain their appetite for an unexpected number of days. In fact, many of the factors that we tend to attribute with a more severe infection have not been shown to correlate with developing a postoperative abscess, including duration of symptoms before presentation, duration of fever, or elevated Table 5 Average LOS for each treatment group based on volume of collection
Volume of LOS (d) collection (mL)
Postoperative WBC on postoperative day fever (no. of days) 7 (×103)
Volume (mL)
Procedure
LOS (d)
P
N30
1.9 ± 0.4 3.3 ± 0.8 4.8 ± 0.6 .02
30-100
8.3 (±3.8) 6.9 (±3.8) 9.8 (±3.5) 10.9 (±5.2) 14.8 (±6.5) 8.7 (±1.5)
.56
b30 30-99 N 100 P
Drain No drain Drain No drain Drain No drain
6.7 ± 0.8 10.3 ± 1.1 13.4 ± 1.1 b.001
Values reported as mean with SD.
14.2 ± 1.2 16.0 ± 0.9 16.7 ± 1.0 .2
N100
Length of stay reported as mean and SD.
.51 .13
Draining postoperative fluid collections after appendectomy WBC [2]. Because of this, it can be difficult to predict who should be investigated for postoperative intraabdominal fluid collections and who will require intervention. Furthermore, the question of whether draining these collections improve outcome becomes important because, if not, the decision to investigate is less relevant. We have demonstrated in this study that when comparing the most common criteria upon which we base discharge from the hospital (fever, WBC, tolerance of regular diet), there was no significant difference between patients who had their postoperative fluid collections drained and those who did not. Likewise, there was no predictable way to identify patients with large collections greater than 100 mL based on symptoms alone. This suggests that the fluid collection may not be the sole source of symptoms and that a full recovery may not be dependent on drainage in all cases. Our findings correlate with several smaller studies that suggest that most patients with postoperative collections can be managed by antibiotics alone. In a study by Okoye et al [6], 23 children investigated after appendectomy were found to have abdominal collections, 21 (91%) of whom recovered with antibiotics alone after an average of 8.3 days. Similarly, in a study by Forgues et al [8], 22 (85%) of 26 patients with postoperative fluid collections were successfully treated with antibiotics alone for an average of 8 days with resolution of symptoms. Although neither study defined what constituted a treatment failure, both concluded that most children improve without drainage. However, the question that was not answered is whether these patients would have improved more quickly had drains been placed. Our study addresses the efficacy of drain placement by comparing the LOS between patients who received drains and those who did not. Although LOS is not a direct measure of recovery, children must meet certain clinical criteria before discharge; and therefore, LOS correlates with recovery time. What we found was that the placement of a drain did not itself significantly impact LOS but that the size of collection did. One weakness of this study is that the patients who received drains, on average, had larger fluid collections than those who did not; and therefore, it is difficult to conclude that the patients with large collections greater than 100 mL would have recovered as quickly had they not received drains because there were only 3 such patients in the no-drain group compared with 18 in the drain group. However, there were nearly equal numbers of children with medium-sized collections (30-100 mL) in both the drain and no-drain groups (15 and 12 patients, respectively); and the average LOS between these children did not differ significantly. Therefore, we can conclude that, for patients with collections less than 100 mL, drainage does not appear to hasten recovery. Whether this remains true for larger collections requires a prospective study to determine. Given that there are likely some children with postoperative fluid collections who will not benefit from drain placement, it is important to consider the potential risks associated with the procedure. Although it does require a high level of subspecialty training, percutaneous drain placement via either the transrectal
1129 or transabdominal route is a relatively safe procedure. A recent study reported a series of 27 children who had transrectal drains placed without any complications [11]. However, there are also reports of complications from percutaneous drain placement, including bowel perforations and hemorrhage [12,13]. In addition, the procedure often requires sedation and, occasionally, general anesthesia using a significant amount of resources. Given these potential risks, it is important to identify which patients benefit from fluid drainage. It can also be argued from this study that we should be more stringent with postoperative imaging. Given that, at postoperative day 6 or 7, the time when most of our patients were imaged, there was no significant difference in the symptoms between children with large vs small collections, it would be prudent to delay imaging for children who are stable but not yet ready for discharge. Those who subsequently improve can be discharged, and those who do not can then be imaged. In some cases, it is not clear whether a postoperative fluid collection itself is problematic or whether it is merely a marker of inflammation and ongoing acute reaction. Interestingly, only 37% of patients who had fluid sampled had positive bacterial cultures; and this did not correlate with the size of the collection. We did find that children with fluid collections greater than 100 mL took longer to defervesce and stayed in the hospital longer. Similarly, in the adult literature, there is evidence to suggest that larger fluid collections, based on the diameter seen on imaging, are less likely to be treated successfully with antibiotics alone [14,15]. Again, given our small numbers, it is difficult to draw conclusions about the benefit of drainage in this specific group of patients; however, for patients with smaller collections, drainage did not seem to shorten the recovery period. Although not specifically evaluated in this study, there are likely subsets of patients who would benefit from drainage of a postoperative fluid collection. For example, some patients develop collections adjacent to the rectum and bladder and experience symptoms such as dysuria, diarrhea, and/or persistent abdominal or pelvic pain. One could surmise that based on the location of the collection, drainage would help to relieve these symptoms. This remains to be formally studied. In addition, there are likely patients who have true abscesses that are not well treated with antibiotics alone, similar to patients presenting with perforated appendicitis who have drains placed followed by interval appendectomy. Given the preliminary data from this study and the potential for reducing patient care costs and morbidity, a prospective study would be beneficial to determine if patients with large fluid collections greater than 100 mL benefit from percutaneous drainage.
References [1] Rothrock SG, Pagane J. Acute appendicitis in children: emergency department diagnosis and management. Ann Emerg Med 2000;36(1): 39-51.
1130 [2] Henry MC, Walker A, Silverman BL, et al. Risk factors for the development of abdominal abscess following operation for perforated appendicitis in children: a multicenter case-control study. Arch Surg 2007;142(3):236-41 [discussion 241]. [3] Lee JH, Park YS, Choi JS. The epidemiology of appendicitis and appendectomy in South Korea: national registry data. J Epidemiol 2010;20(2):97-105. [4] Serour F, Herman A, Witzling M, et al. Sonographic findings following appendectomy for uncomplicated appendicitis in children. Pediatr Radiol 2009;39(9):926-32. [5] Aveline B, Guimaraes R, Bely N, et al. Intraabdominal serous fluid collections after appendectomy: a normal sonographic finding. AJR Am J Roentgenol 1993;161(1):71-3. [6] Okoye BO, Rampersad B, Marantos A, et al. Abscess after appendicectomy in children: the role of conservative management. Br J Surg 1998;85(8):1111-3. [7] Gorenstein A, Gewurtz G, Serour F, et al. Postappendectomy intraabdominal abscess: a therapeutic approach. Arch Dis Child 1994;70 (5):400-2. [8] Forgues D, Habbig S, Diallo AF, et al. Post-appendectomy intraabdominal abscesses—can they successfully be managed with the sole use of antibiotic therapy? Eur J Pediatr Surg 2007;17(2):104-9.
H.G. Piper et al. [9] Heloury Y, Baron M, Bourgoin S, et al. Medical treatment of postappendectomy intraperitoneal abscesses in children. Eur J Pediatr Surg 1995;5(3):149-51. [10] Chen C, Botelho C, Cooper A, et al. Current practice patterns in the treatment of perforated appendicitis in children. J Am Coll Surg 2003;196(2):212-21. [11] Koral K, Derinkuyu B, Gargan L, et al. Transrectal ultrasound and fluoroscopy-guided drainage of deep pelvic collections in children. J Pediatr Surg 2010;45(3):513-8. [12] Buckley BT, Goodwin M, Boardman P, et al. Percutaneous abscess drainage in the UK: a national survey and single centre study. Clin Radiol 2006;61(1):55-64 [discussion 53-4]. [13] Keckler SJ, Tsao K, Sharp SW, et al. Resource utilization and outcomes from percutaneous drainage and interval appendectomy for perforated appendicitis with abscess. J Pediatr Surg 2008;43(6): 977-80. [14] Kumar RR, Kim JT, Haukoos JS, et al. Factors affecting the successful management of intra-abdominal abscesses with antibiotics and the need for percutaneous drainage. Dis Colon Rectum 2006;49(2):183-9. [15] Bamberger DM. Outcome of medical treatment of bacterial abscesses without therapeutic drainage: review of cases reported in the literature. Clin Infect Dis 1996;23(3):592-603.