Background. A protocol of ultrasonography (US) followed by computed tomography with rectal contrast (CTRC) has been shown to be 94% accurate in the diagnosis of acute appendicitis in children.
Objective. To evaluate the changes in patient management and costs of a protocol using US and CTRC in the evaluation of appendicitis in children.
Design, Setting, and Subjects. Prospective cohort study of 139 children between 3 and 21 years of age who had equivocal clinical findings for acute appendicitis seen in the emergency department of a large, urban pediatric teaching hospital between July 1998 and December 1998.
Protocol. Children with equivocal clinical presentations for acute appendicitis were prospectively evaluated with US. Patients with positive findings for acute appendicitis went directly to the operating room. Patients with negative or equivocal findings on US underwent CTRC. Surgical management plans were recorded before imaging, after US, and after CTRC.
Main Outcome Measures. Surgical management plans before and after the imaging protocol as well as total hospital direct and indirect costs incurred or saved by each change in management were determined. Costs were obtained through the hospital's cost database and by ratios of costs to charges.
Results. Of the 139 children, the protocol resulted in a beneficial change in management in 86 children (61.9%), no change in management in 50 children (36.0%) and an incorrect change in management in 3 children (2.1%). US alone resulted in a beneficial change in management decision in 12/31 children (38.7%), while US followed by CTRC resulted in a beneficial change in management in 74/108 children (68.5%). The protocol resulted in a total cost savings of $78 503.99 or $565/patient.
Conclusion. A protocol of US followed by CTRC in children with negative or equivocal US examinations results in a high rate of beneficial change in management as well as in total cost savings in children with equivocal clinical presentations for suspected appendicitis.
The diagnosis of acute appendicitis in children continues to be a challenge because the initial presentation of the disease is often obscure and closely imitated by other common childhood diseases.1–7 Many children with suspected appendicitis are often admitted to the hospital for an observation period before the diagnosis is made.8–11 However, morbidity and mortality from appendicitis are most often caused by complications associated with delayed diagnosis.12–18 Hence, prompt diagnosis and management remain critical features when considering the diagnosis of childhood appendicitis.
Recent advances in diagnostic imaging have given clinicians important modalities to aid them in the diagnosis of childhood appendicitis. Ultrasonography (US) is the most widely used technique in the pediatric population because it is noninvasive and does not involve radiation.19–23 However, US is highly operator-dependent and only rarely is the normal appendix visualized sonographically.24 Computed tomography (CT) is increasingly being used as the primary imaging modality in adults with signs and symptoms of acute appendicitis with high sensitivity and specificity for the diagnosis.24–34 The highest accuracy in adults has been found with CT using rectal contrast (CTRC) to outline the appendix.24–30 This technique has been shown to improve the diagnosis and management of acute appendicitis, while also reducing the use of hospital resources.25,26Recently, a protocol of CTRC after a negative or equivocal ultrasound examination has been evaluated in children with an overall accuracy of 94% for the diagnosis of acute appendicitis.35
The purpose of this investigation was to assess the beneficial and detrimental changes in patient management following a protocol using US and CTRC in children with suspected acute appendicitis and to evaluate the use of hospital resources using the US–CTRC protocol.
Children and adolescents between the ages of 3 and 21 years with equivocal findings for suspected acute appendicitis who presented to the emergency department (ED) of Children's Hospital, Boston, Massachusetts, from July 1998 to December 1998, were prospectively identified. Patients with equivocal findings were defined as those children with concerning, but not classic signs or symptoms for acute appendicitis. Patients who were pregnant, who had previous appendectomy, or who had a contraindication to rectal contrast were ineligible. The hospital's institutional review board approved the study.
Details of the study protocol have been described previously.35 The consulting surgical senior resident, who is in the fourth or fifth postgraduate year, under the supervision of an attending pediatric surgeon, evaluated all patients with suspected appendicitis in the ED. Children with equivocal presentations for appendicitis comprised the study cohort and initially underwent pelvic US. If the ultrasound was definitive for appendicitis, no further imaging was performed and the patient underwent appendectomy. If the appendix was not visualized by ultrasound or if the sonogram was equivocal, limited CTRC of the pelvis was performed. Results of both the ultrasound and CTRC were immediately made known to the treating physicians. Both studies were performed by 1 of 6 pediatric radiology fellows between 5:00 pm and 8:00 am or by an attending pediatric radiologist between 8:00 am and 5:00 pm.
The consulting surgeons were asked their management plans before imaging, after US, and after CTRC and were recorded by the radiologist performing the studies. The 3 management plans included: discharge home from the ED, admit to hospital for an observation period, or proceed to operating room (OR) for appendectomy. Changes in management were determined by the principal investigator by comparing the preimaging disposition with that following the US–CTRC protocol. Correct changes in management decisions were defined as those decisions that were necessary and/or benefited the child (ie, a child with appendicitis who would have been discharged from the hospital or admitted for inpatient observation that went directly to the OR). Incorrect changes in management were defined as those that were unnecessary and/or not beneficial for the patient (ie, a child without appendicitis who was to be discharged from the hospital or admitted for inpatient observation who underwent appendectomy). Data regarding beneficial changes in patient management using US and CTRC individually have been published previously.35
Final Diagnosis and Patient Follow-Up
Final diagnoses were determined by pathologic examination of the appendix for patients who underwent appendectomy and by clinical follow-up for those children managed nonoperatively. All children who did not undergo appendectomy were followed up by telephone 2 weeks after their ED visit. The Children's Hospital medical records of all patients were reviewed 4 to 6 months after study completion.
Because 80% of children with appendicitis have appendiceal perforation within 48 hours,12 we first assumed a conservative rate of 50% appendiceal perforation in those children with appendicitis who would have been discharged from the hospital from the ED. We then assumed that no child with appendicitis who would have been discharged from the hospital from the ED would have appendiceal perforation (0% perforation rate). Second, we assumed that children with appendicitis would eventually need appendectomy. Finally, the costs of a negative laparotomy and positive laparotomy were assumed to be the same.
The 1998 direct and indirect average costs for nonperforated appendicitis, perforated appendicitis, and a hospital observation period for right lower quadrant abdominal pain were obtained from the hospital cost database at Children's Hospital, Boston, Massachusetts. All costs are in 1998 US dollars. The cost of an inpatient hospitalization day includes the daily room cost, intravenous fluids, laboratory tests, and medications administered. The costs for a nonperforated and perforated appendicitis do not include surgeons' fees. ED costs were not included in the analysis. The costs of pelvic US and CTRC were calculated from hospital charges with a cost-to-charge ratio of .47.36 US and CTRC costs include costs of radiographic interpretation. The average number of inpatient observation days for children with and without appendicitis were calculated from the actual patient observation time of 351 children between 1996 and 1997.
Costs were calculated for each child based on the change in management following the US–CTRC protocol. Patients without appendicitis who were to be observed before the imaging protocol and were subsequently discharged from the hospital after imaging as well as patients with appendicitis who were to be observed initially and who subsequently went directly to the OR had inpatient observation hospitalization costs subtracted. One half of those children with appendicitis who would have been discharged from the hospital and who, after imaging, went directly for appendectomy had perforation costs subtracted. Patients without appendicitis who would have had appendectomy and were subsequently discharged from the hospital or hospitalized for observation had appendectomy costs subtracted. Children without appendicitis who would have been observed and who, after imaging, went to the OR had appendectomy costs added. Costs of US were added for the 139 children and those of CTRC were added for the 108 children.
The demographics and outcomes of the cohort have been previously reported.35 One hundred thirty-nine children had equivocal clinical presentations for appendicitis and were enrolled as the study cohort. The mean (standard deviation) age of the cohort was 11.1 (4.25) years (range: 3–20 years; median: 11 years). Two patients were >18 years of age. Seventy of the children (50.4%) were male. Fifty children (36%) had pathologically proven appendicitis. Eleven of the 50 patients (22%) had perforated appendicitis and 3 (6%) had a gangrenous appendix.
Thirty-one of the 139 children were imaged with US only. Of these, 19 children underwent appendectomy immediately after US and all had pathologically proven appendicitis. One 5-year-old boy had an equivocal US examination and was admitted for inpatient observation with progression of symptoms. He underwent appendectomy 8 hours after admission and pathologic examination revealed appendicitis. Eleven children who had negative US examinations did not undergo CTRC due to resolved symptoms (7/11), established alternative diagnoses (1/11), visualization of a normal appendix (2/11), or patient inability to retain the rectal contrast (1/11). The latter was an 11-year-old developmentally delayed male with a negative US examination who was hospitalized after failed CTRC and discharged within 24 hours after his symptoms resolved. He returned 3 days later with perforated appendicitis.
One hundred eight patients underwent CTRC imaging after a negative or equivocal US. Thirty-one patients went immediately to the OR after CTRC. Of these, 28 children (90.3%) had pathologically proven appendicitis. Seven children (25%) had perforated appendicitis and 2 had a gangrenous appendix. Twenty-five patients were hospitalized for observation; 24 (96%) did not have appendicitis. One patient had an initial CTRC interpretation of terminal ileitis and was subsequently diagnosed with a perforated appendicitis. He underwent percutaneous drainage followed by interval appendectomy. Fifty-two children were discharged from the hospital from the ED, none of whom had appendicitis.
Changes in Management Decisions
The US–CTRC protocol resulted in a beneficial change in patient management in 86/139 children (61.9%), no change in management in 50/139 children (36.0%), and an incorrect change in 3/139 children (2.1%). Of the 31 children who underwent US alone, a beneficial change in management decision occurred in 12 children (38.7%), an incorrect change in 1 (3.2%), and no change in management in 18 children (58.1%; Tables 1 and2). US followed by CTRC resulted in a beneficial change in management in 74/108 children (68.5%), an incorrect change in 2/108 (1.9%), and no change in management in 32/108 patients (29.6%; Tables 1 and 2).
The average direct and indirect costs for each diagnosis and radiographic modality are shown in Table 3. From these values, the average amount saved or incurred by each patient in the protocol was calculated based on the change in management decisions before and after imaging (Table 4). Assuming a 50% perforation rate in those children with appendicitis who would have been discharged from the hospital from the ED before imaging, US alone in the 31 children who did not undergo CTRC saved $20 422.14 and US followed by CTRC saved $58 081.85 in the remaining 108 children. This resulted in total net savings of $78 503.99 or $564.78 per patient. Assuming a more conservative 0% perforation rate in these same children, US alone saved $4372.83, while US followed by CTRC saved $52 732.08 for total net savings of $57 104.91 or $410.83 per child.
Advances in US and CT over the past decade have allowed for expedient ED diagnosis and management decisions in children with suspected appendicitis. Earlier diagnosis is essential in decreasing the perforation rate and its associated complications in those children with appendicitis. In addition, inpatient observation time and resultant costs can be reduced if a diagnosis is expediently made in the ED. A protocol of US followed by CTRC in those children with equivocal presentations for acute appendicitis has been shown to be accurate, highly sensitive, and specific.35
Previous studies have shown that in the adult population, routine use of CT lowers the cost and use of hospital resources in caring for patients with clinically suspected appendicitis.25,26 In addition, models using CT constructed from retrospective inpatient admissions for suspected appendicitis in children have also been shown to markedly reduce morbidity as well as the acute care costs associated with clinically suspected appendicitis.37
We have prospectively shown that a protocol of US followed by CTRC in a cohort of children with equivocal clinical findings for suspected appendicitis can reduce both morbidity and acute care costs as well as produce a net savings of $565 per child. Use of the protocol resulted in a correct change in management in 86/139 patients (61.9%), including preventing children with appendicitis from being discharged from the hospital or observed in the hospital as well as preventing children without appendicitis from undergoing unnecessary laparotomy.
Our study had a few limitations. First, several assumptions were made that may not be entirely valid. We assumed that 50% of patients with appendicitis who were discharged from the hospital would subsequently suffer appendiceal perforation. Although 80% of children with acute appendicitis will perforate within 48 hours,12 those children who were sent home may have been diagnosed before perforation. However, even if those patients were not treated as perforated appendicitis (0% perforation rate), the overall cost savings would be reduced from $78 503.99 to $57 104.91 or $411 per patient, which remains a substantial net savings. Second, the use of the cost-to-charge ratio for determining cost for the radiologic imaging studies is an estimate and may not reflect the accurate direct and indirect costs incurred by the hospital for these studies. In addition, our analysis only accounted for the short-term costs and morbidity associated with acute appendicitis. Additional costs, morbidity and even mortality may be incurred by the long-term complications of appendicitis, particularly perforated appendicitis.
When the imaging protocol was first implemented in our institution, many surgeons were initially reticent about discharging patients from the ED with negative CTRC scans because its accuracy in children had not yet been determined. Hence, many patients without appendicitis were admitted to the hospital for a period of inpatient observation. As the surgeons became more comfortable with the performance of CTRC, children were increasingly discharged from the hospital from the ED with appropriate follow-up. Thus, there would have been even greater cost savings than what we have reported in this study if all of the well-appearing children with negative CTRC scans were discharged from the hospital. In addition, the inconvenience of inpatient observation to the child as well as to the family would have been eliminated.
The protocol of US and CT was performed in those children with equivocal clinical findings for acute appendicitis, and thus, routine use of the protocol on all children with suspected appendicitis cannot be justifiably advocated. However, use of the US–CTRC protocol in those children with equivocal presentations for acute appendicitis has been shown to be highly accurate as well as to decrease morbidity and the acute care costs associated with the disease. Because we have shown both clinical benefit to patients as well as cost reduction, our data support the use of such a protocol in the management of children with equivocal presentations for acute appendicitis.
We thank John Howley in the Department of Finance for his help and patience; and Gary Fleisher, MD, and Constantino S. Peña, MD, for their continued support and encouragement.
- Received October 22, 1999.
- Accepted January 11, 2000.
Reprint requests to (B.M.G.P.) Division of Emergency Medicine, Children's Hospital, 300 Longwood Ave, Boston, MA 02215. E-mail:
- US =
- ultrasonography •
- CT =
- computed tomography •
- CTRC =
- computed tomography with rectal contrast •
- ED =
- emergency department •
- OR =
- operating room
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- Copyright © 2000 American Academy of Pediatrics