Impact of an Acute Care Surgery Clinical Pathway on Patient Outcomes in Acute Appendicitis

Abstract

Objectives:

Acute care surgery (ACS) encompasses surgical critical care, emergency general surgery, and the surgical management of trauma. Following ACS implementation at our institution, we developed a perioperative clinical pathway for acute appendicitis (AA) to improve efficiency and standardize post-operative care. The purpose of our study is to assess patient outcomes utilizing our ACS clinical pathway for patients with AA.

Methods:

This is a retrospective cohort study involving patients admitted to our tertiary care facility with AA who underwent appendectomy. Patients were classified by pre-implementation (January 1, 2016−July 31, 2018) and post-implementation (August 1, 2018−December 31, 2020) of our ACS clinical pathway. The primary outcome was hospital length of stay (LOS). Statistical analysis was performed using SAS with a p-value <0.05 determined as significant.

Results:

Of the 492 patients included, 225 were in the pre- and 267 were in the post-implementation cohorts. Hospital LOS was substantially decreased in the post-implementation cohort (31.2 vs. 50.4 h, p < 0.001). The post-implementation group had a substantial decrease in computed tomography (CT) to operating room (OR) start time (6.81 vs. 11.4 h, p < 0.001), CT to antibiotic agents’ administration (2.20 vs. 3.37 h, p < 0.001), inpatient opioid utilization (125 morphine equivalents [ME] vs. 172 ME, p < 0.001), and discharge antibiotic agents’ prescription rates (23.6% vs. 30.7%, p = 0.077). Recovery unit discharges (20 vs. 9%, p < 0.001) were increased in the post-implementation cohort.

Conclusion:

Our ACS clinical pathway for AA resulted in earlier surgical intervention, enhanced opioid and antimicrobial stewardship, and gains in surgical care efficiencies.

The American Association for the Surgery of Trauma introduced the concept of acute care surgery (ACS) in 2005 to manage patients with acute general surgical conditions in areas of critical care, emergency surgery, and trauma.^1–4 Trauma and emergency general surgery patients account for nearly 20% of all admissions to hospitals in the United States, accounting for $85 billion or 25% of all inpatient costs.^5,6 The ACS model was initially developed to increase efficiency, standardize post-operative care, and enhance access for patients with acute general surgical conditions.^7,8 This paradigm shift that promotes care for these patients into a structured and all-encompassing service recognizes the physiologic complexity when caring for these patients. Now ACS models are increasingly being adopted at many institutions across the country.^9,10

Previous studies have demonstrated that the ACS approach is more efficient with decreased length of stay (LOS) and improved patient outcomes compared with more traditional surgical care models.^8,10 Traditional call models in emergency general surgery have been shown to negatively impact patient outcomes and lead to greater rates of complications.^11,12 Furthermore, emergency general surgery presentations account for substantial health-care–related costs and standardized care approaches have been shown to decrease the cost burden.⁶

Interventions that improve post-operative LOS at our institution became a focal point for quality improvement initiatives. Acute appendicitis (AA) is a common emergency surgical condition that often takes a predictable perioperative course—one easily amenable to standardization. Laparoscopic appendectomy has a reported LOS of 30 hours in traditional models.¹¹ As such, AA was our initial surgical target for developing and implementing a standardized evidence-based clinical pathway.

The purpose of our study is to assess efficiency and patient outcomes utilizing our ACS clinical pathway for patients with AA. We hypothesized that standardized care utilizing our evidence-based pathway would lead to faster time to operative intervention and decreased hospital LOS with similar re-admission rates when compared with patients from the traditional surgical model.

Patients and Methods

This was a retrospective study of patients treated at our tertiary referral center who were diagnosed with AA and underwent appendectomy. The study received approval from the Saint Luke’s Health System Institutional Review Board. All patients more than 17 years old undergoing a laparoscopic appendectomy at St. Luke’s Hospital of Kansas City, an academic medical center that is part of Saint Luke’s Health System, between January 1, 2016, and December 31, 2020, were included in the study. Patients were classified by pre-(January 1, 2016−July 31, 2018) and post-implementation (August 1, 2018−December 31, 2020) of our ACS clinical pathway.

ACS clinical pathway

Our ACS clinical pathway for AA was implemented on August 1, 2018, with the intent to provide efficient and progressive care for adult patients presenting at our institution (Fig. 1). Our pathway was developed from previous data supporting a standardized pre-operative antibiotic agents’ regimen, recovery room discharge for patients with non-perforated appendicitis, standard operative room definition of a perforation, and short courses of post-operative antibiotic agents for patients with perforated appendicitis.^13–15 Adult patients who underwent operative management for AA prior to implementation of our clinical pathway were included as a comparison group (pre-implementation). The patients in the pre-implementation group were treated by elective surgeons taking general surgery call. Patients identified by initial computed tomography (CT) imaging to have a perforation with abscess formation were managed non-operatively with percutaneous drain placement by Interventional Radiology (IR). These patients were excluded from our study.

FIG. 1.

Saint Luke’s Hospital of Kansas City evidence-based clinical protocol for patients diagnosed with acute appendicitis.

The following outlines the ACS pathway from initial emergency department (ED) presentation to discharge.

Emergency department

Following an ED provider’s evaluation, a surgical consult was placed for patients diagnosed with AA by clinical presentation, laboratory values, and radiographic imaging. Patients transferred from an outside hospital were sent to our ED for evaluation. Following evaluation by a surgical resident and the in-house acute care surgeon, a case request for appendectomy was placed in the electronic medical record. Patients were then transferred to the operating room at the next available opening for surgery.

Operating room

Patients were consented for a laparoscopic appendectomy and received a pre-operative dose of ceftriaxone plus metronidazole or piperacillin–tazobactam. In the case of penicillin allergy, ciprofloxacin plus metronidazole was administered. A standard three-incision laparoscopic appendectomy was performed by one of six acute care surgeons. All operations were performed with the assistance of a resident physician. All trocar sites were injected with local anesthesia intra-operatively. Patients received parenteral ketorolac tromethamine (Toradol; ACI Pharmaceuticals, New York, NY) during the procedure if they were less than 65 years old with normal renal function. Patients who required conversion to an open procedure had a standard midline incision with primary abdominal closure following the procedure.

Post-operative treatment

Patients with non-perforated appendicitis were transferred to our recovery room following surgery, given an oral diet, and discharged home if hemodynamically stable and their pain and nausea were well controlled. Before discharge to home, patients and their families were provided written instructions regarding diet, activity, and analgesic use. Each patient was given a prescription of 10 oxycodone 5 mg tablets, to be taken every 4 hours as needed, with ibuprofen or acetaminophen to be used as an adjunct.¹⁶

Patients with non-perforated appendicitis and poor post-operative pain control or nausea refractory to medications were admitted to the hospital. Furthermore, patients diagnosed with perforated appendicitis in the operating room or those converted to an open procedure were also admitted following appendectomy.

Post-discharge follow-up for patients without a perforation includes a call from an office nurse the day after hospital discharge and a second call when the pathology report is complete. Patients are then offered a follow-up appointment in our office at the time of second call. For patients with a perforation identified at the time of surgery, they are offered a follow-up appointment in our office at the time of hospital discharge.

Baseline demographic data including age, gender, body mass index, primary language, insurance status, race/ethnicity, vital signs, transfer from another facility, and admission and discharge white blood cell count were collected. The primary outcome was hospital LOS. Secondary endpoints included time from initial imaging to incision, length of operation, recovery room discharge rates, inpatient opioid utilization in morphine equivalents (ME), discharge antibiotic agents’ prescription rates, and 30-day re-admission rates. Comparative analysis was performed in SAS using Chi-square or Fisher exact test, exact test for categorical variables, and t-test or the Wilcoxon rank sum test for continuous variables. Multi-variate regression analysis identifying factors that predict outcomes for our ACS pathway was also performed. Statistical significance was determined with a p-value <0.05.

Results

From January 2016 to December 2020, 492 patients were diagnosed with AA and underwent appendectomy; 225 patients (46%) were treated with the traditional surgical model (pre-implementation) and 267 patients (54%) were treated after initiating our ACS pathway (post-implementation). Baseline demographics were mostly consistent between groups (Table 1) with more female patients in the pre-implementation group (56 vs. 44%) and more patients transferred to our institution with AA (24 vs. 9%) in the post-implementation group. Initial pre-operative vital signs as well as admission and discharge white blood cell count were similar for patients treated in the traditional model and the ACS pathway (Table 2). More patients diagnosed with perforated appendicitis were found in our post-implementation group (29.6 vs. 6.2%, p < 0.001).

Table 1.

Patient Demographics, Primary Language, and Insurance Status in Patients with Acute Appendicitis

	Traditional model n = 225	Acute care surgery model n = 267	p
Age in years, mean (SD)	39.2 (17.4)	39 (17.4)	0.877
Female, n (%)	125 (55.6)	117 (43.8)	0.009
BMI, mean (SD)	28.3 (7.2)	28.2 (6.9)	0.850
English as primary language, n (%)	212 (94.2)	257 (96.3)
Insurance status, n (%)			0.842
Private	144 (64)	176 (65.9)
Public	53 (23.6)	57 (21.3)
Self-pay	28 (12.4)	34 (12.7)
Race/Ethnicity, n (%)			0.215
Black	29 (12.9)	22 (8.3)
White	170 (75.6)	208 (78.2)
Hispanic	23 (10.2)	29 (10.9)
Asian	1 (0.4)	5 (1.9)
Other	18 (8%)	26 (9.8)
Patient transfer, n (%)	20 (8.9)	63 (23.6)	<0.001

BMI = body mass index; SD = standard deviation.

Table 2.

Clinical Characteristics for Patients Diagnosed with Acute Appendicitis

	Traditional model n = 225	Acute care surgery model n = 267	p
Initial pre-operative vital signs
Pre-operative T-max, mean (SD)	98.4 (0.7)	98.7 (0.8)	0.256
SBP, mm of Hg, mean (SD)	127.6 (17)	131.4 (17.3)	0.016
Pulse, bpm, mean (SD)	85.9 (16.8)	86.2 (17.3)	0.850
RR, mean (SD)	17.4 (2.6)	17.4 (4.5)	0.956
WBC count admission, mean (SD)	12.8 (4.2)	12.9 (4.3)	0.877
Discharge WBC count if applicable, mean (SD)	11.1 (3.7)	11.7 (3.8)	0.083
Perforated appendicitis, n (%)	14 (6.2)	79 (29.6)	<0.001

SBP = systolic blood pressure; RR = respiratory rate; WBC = white blood cell.

For the primary outcome, hospital LOS was shorter in the post-implementation group (31.2 vs. 50.4 h, p < 0.001), in addition to post-operative LOS (13 vs. 18 h, p < 0.001, Table 3). Time from CT imaging to operating room start was substantially reduced in the post-implementation group (319 vs. 624 min, p < 0.001), as was the likelihood of being discharged home from the recovery room (20% vs. 9%, p < 0.001, Table 3). There was also a decrease in time from CT imaging to antibiotic agents’ administration (2.20 vs. 3.37 h, p < 0.001) and inpatient opioid utilization in morphine equivalents (125 ME vs. 172 ME, p < 0.001) in our post-implementation group. There was no difference in median operative time.

Table 3.

Clinical Outcomes for Patients Diagnosed with Acute Appendicitis

	Traditional modeln = 225	Acute care surgery modeln = 267	p
Discharge from recovery, n (%)	20 (8.9)	54 (20.2)	<0.001
CT to OR start in minutes, median (range)	624 (364, 940)	319 (215, 501)	<0.001
OR time in minutes, median (range)	85 (74, 103)	92 (76, 109)	0.040
Post-operative LOS in hours, median (range)	18 (8, 26)	13 (5, 21)	<0.001
Opioid dose in morphine equivalents, median (range)	130 (96, 185)	109.5 (80, 146)	<0.001
30-d hospital re-admissions, n (%)	9 (4%)	19 (7.1%)	0.137

CT = computed tomography; OR = operating room; LOS = length of stay; PACU = post-anesthesia care unit.

There were no statistically significant differences between the two groups by unplanned 30-day hospital re-admissions (7.1 vs. 4%, p = 0.137, Table 3). Multi-variate analysis identifying independent factors that predict outcomes for our ACS pathway showed a decreased post-operative LOS, decreased CT to operating room start, decreased inpatient opioid utilization in ME, and greater rates of recovery room discharge (Table 4).

Table 4.

Multi-variate Analysis Identifying Independent Factors That Predict Outcomes for Our Acute Care Surgery Clinical Pathway

Parameters	Odds ratio or beta estimate	95% CI	p
Post-operative LOS, hours	−9.6	−16.9, −2.4	0.009
CT to OR start, minutes	−260	−336, −185	<0.001
OR time, minutes	1.69	−4.01, 7.39	0.560
Opioid dose in morphine equivalents	−63	−102, −23	0.002
Discharge from recovery	2.87	1.62, 5.06	0.003
Presence of Perforation	6.71	3.6, 12.5	<0.001

CI = confidence interval.

Discussion

At our urban academic medical center, we have successfully adopted an ACS model that utilizes standardized clinical pathways to treat patients with urgent surgical conditions. Our efforts to improve efficiency and decrease post-operative LOS led to the development of an evidence-based and standardized algorithm for patients diagnosed with AA. Despite the growing success of pathway use in ACS models,¹⁷ many academic medical centers have yet to adopt this approach. Implementation of the protocol was associated with a decrease in post-operative LOS, decreased time to operative intervention, and increased recovery room discharge with no substantial differences in post-operative complications or 30-day hospital re-admissions.

Efforts to reduce hospital LOS while limiting complications following surgery have been the focus for expanding fast-track clinical pathways in ACS. Fast-track clinical pathways were first described in cardiac surgery and subsequently developed for procedures in colorectal, breast, bariatric, and hepatobiliary surgery.¹⁸ These pathways are now used in both adult and pediatric patients undergoing urgent surgical interventions.^14,17 Furthermore, these clinical pathways have been shown to help mitigate disparities in patient outcomes.¹⁹ Following the implementation of an ACS model at our level 1 trauma center, our evidence-based ACS pathway, dictated by clinical symptoms, was created to standardize the pre- and post-operative management for patients with AA.

Our pathway focuses on both improving the flow of patients through different departments after the diagnosis is made and utilizing our standard protocol (Fig. 1). Patients with non-perforated appendicitis are encouraged to discharge home from the recovery room with a limited opioid supply.^16,20 In patients with perforated appendicitis, we standardized the management that minimizes prolonged antibiotic agents¹⁵ and utilized IR for abscess cavity drainage.²¹ We speculate the substantial increase in diagnosing perforated appendicitis after implementing our protocol (Table 2) to formally adopting an evidence-based standard definition for perforation.¹³

One of the principal reasons behind the success of our clinical pathway relies on enhanced communication from our team members to the patients once the diagnosis of AA is made. Each patient is evaluated by both a surgical resident and the in-house acute care surgeon, emphasizing the potential for recovery room discharge if no perforation is found in the operating room. The importance of recovery room or same-day discharge following surgery for AA is a point of emphasis for fast-track protocols in ACS to help improve efficiency.¹⁷ In addition, institutions have emphasized ED to operating room pathways for low acuity ACS conditions to combat bed capacity issues. With our 20% recovery room discharge rate that does not impact 30-day hospital re-admissions, our pathway demonstrates high-quality surgical care without compromising safety. We expect this percentage to increase as our protocol matures with continued improvement in staff education.

The implementation of our evidence-based clinical pathway can be an example to other institutions to adopt a formal ACS model that focuses on delivering efficient and standardized care to patients who require urgent surgical intervention. Additionally, the model can be used to discover novel ways to impact outcomes for other common presentations that require surgical intervention. With an increasing focus on optimizing clinical resources and analyzing patient satisfaction scores, standardized pathways in ACS can help reduce healthcare costs without compromising patient safety or patient satisfaction.

There were several limitations in our study. One limitation is the retrospective study design format and our inability to access records of patients who may potentially follow up with complications outside our health system. Despite this possibility, we often experience that patients with post-operative complications are transferred back to our hospital for care management, minimizing some of the concern. Another limitation relates to a potential selection bias for comparing patients following the implementation of our ACS protocol with historical control groups, although baseline characteristics were relatively similar between groups (Table 2).

Conclusions

We have successfully implemented an ACS evidence-based clinical pathway at our urban, academic institution for patients diagnosed with AA. Through our multi-disciplinary approach, we navigated the delicate balance of implementing a protocol that expedites patient throughput while minimizing complications and hospital re-admissions. We were able to effectively reduce hospital LOS, minimize inpatient opioid requirements, and increase recovery room discharge with no substantial increase in 30-day hospital re-admission rates. We hope that our study will lead to further adoption of evidence-based pathways in ACS that focus on improved safety and efficiency while reducing healthcare resource utilization.

Footnotes

Acknowledgments

The authors would like to recognize and thank Caroline Murray and Jacob Hunter for their contributions to this article as research coordinators.

Authors’ Contributions

N.I.: Conceptualization, methodology, and writing original draft. G.T.: Conceptualization, methodology, and writing original draft. C.F.: Conceptualization, methodology, and writing original draft. K.K.: Methodology, validation, and formal analysis. N.B.: Methodology, validation, manuscript editing, and reviewing. T.O.: Methodology, validation, manuscript editing, and reviewing. A.F.: Methodology, validation, manuscript editing, and reviewing. J.G.: Methodology, validation, manuscript editing, and reviewing. D.A.: Manuscript editing and reviewing. T.N.-B.: Manuscript editing and reviewing. S.N.: Conceptualization, manuscript editing and reviewing. L.A.B.: Principal investigator, conceptualization, methodology, manuscript writing, editing and reviewing, and supervision.

Author Disclosure Statement

The authors have nothing to disclose.

Funding Information

This study has been supported by Saint Luke’s Health System Foundation.

References

Committee to Develop the Reorganized Specialty of Trauma SCC, Emergency S. Acute care surgery: Trauma, critical care, and emergency surgery. J Trauma, 2005; 58(3):614–616; doi: 10.1097/01.ta.0000159347.03278.e1

Kim

, Dabrowski

, Reilly

, et al. Redefining the future of trauma surgery as a comprehensive trauma and emergency general surgery service. J Am Coll Surg, 2004; 199(1):96–101; doi: 10.1016/j.jamcollsurg.2004.02.025

Spain

, Miller

. Education and training of the future trauma surgeon in acute care surgery: Trauma, critical care, and emergency surgery. Am J Surg, 2005; 190(2):212–217; doi: 10.1016/j.amjsurg.2005.05.014

Pryor

, Reilly

, Schwab

, et al. Integrating emergency general surgery with a trauma service: Impact on the care of injured patients. J Trauma, 2004; 57(3):467–471; discussion 71–3; doi: 10.1097/01.ta.0000141030.82619.3f

Murphy

, Coleman

, Karam

, et al. A national study defining 1.0 full-time employment in trauma and acute care surgery. J Trauma Acute Care Surg, 2022; 92(4):648–655; doi: 10.1097/TA.0000000000003504

Ogola

, Gale

, Haider

, et al. The financial burden of emergency general surgery: National estimates 2010 to 2060. J Trauma Acute Care Surg, 2015; 79(3):444–448; doi: 10.1097/TA.0000000000000787

Hardy

, Metcalfe

, Clouston

, et al. The impact of an acute care surgical service on the quality and efficiency of care outcome indicators for patients with general surgical emergencies. Cureus, 2019; 11(6):e5036; doi: 10.1503/cjs.010718

Cubas

, Gomez

, Rodriguez

, et al. Outcomes in the management of appendicitis and cholecystitis in the setting of a new acute care surgery service model: Impact on timing and cost. J Am Coll Surg, 2012; 215(5):715–721; doi: 10.1016/j.jamcollsurg.2012.06.415

McGill

, Dhanasekara

, Caballero

, et al. Improved outcomes in treating acute biliary disorders with a shift-based acute care surgery model. Am Surg, 2023; 89(5):1787–1792; doi: 10.1177/00031348221074229

10.

Dhanaskeara

, Caballero

, Moolupuri

, et al. Patient outcomes in laparoscopic appendectomy with acute surgical care model compared to traditional call. J Surg Res, 2023; 281:282–288; doi: 10.1016/j.jss.2022.08.036

11.

Schaetzel

, Dirks

, Davis

. Comparison of outcomes of patients with acute appendicitis between an acute care surgery model and traditional call coverage model in the same community. Am J Surg, 2016; 212(6):1083–1089; doi: 10.1016/j.amjsurg.2016.09.006

12.

Earley

, Pryor

, Kim

, et al. An acute care surgery model improves outcomes in patients with appendicitis. Ann Surg, 2006; 244(4):498–504; doi: 10.1097/01.sla.0000237756.86181.50

13.

St Peter

, Sharp

, Holcomb

3rd , et al. An evidence-based definition for perforated appendicitis derived from a prospective randomized trial. J Pediatr Surg, 2008; 43(12):2242–2245; doi: 10.1016/j.jpedsurg.2008.08.051

14.

Benedict

, Sujka

, Sobrino

, et al. Same-day discharge for nonperforated appendicitis in children: An updated institutional protocol. J Surg Res, 2018; 232:346–350; doi: 10.1016/j.jss.2018.06.057

15.

Sawyer

, Claridge

, Nathens

, et al. STOP-IT Trial Investigators. Trial of short-course antimicrobial therapy for intraabdominal infection. N Engl J Med, 2015; 372(21):1996–2005; doi: 10.1056/NEJMoa1411162

16.

Sim

, Hawkins

, Gave

, et al. How low can you go: Achieving postoperative outpatient pain control without opioids. J Trauma Acute Care Surg, 2019; 87(1):100–103; doi: 10.1097/TA.0000000000002295

17.

Fazzalari

, Srinivas

, Panjwani

, et al. A fast-track pathway for emergency general surgery at an academic medical center. J Surg Res, 2021; 267:1–8; doi: 10.1016/j.jss.2021.04.012

18.

Ljungqvist

, Scott

, Fearon

. Enhanced recovery after surgery: A review. JAMA Surg, 2017; 152(3):292–298; doi: 10.1001/jamasurg.2016.4952

19.

Benedict

, Sujka

, Sobrino

, et al. Mitigating disparity in children with acute appendicitis: Impact of patient-driven protocols. J Pediatr Surg, 2021; 56(4):663–667; doi: 10.1016/j.jpedsurg.2020.10.003

20.

Biesboer

, Al Tannir

, Karam

, et al. A prescribing guideline decreases postoperative opioid prescribing in emergency general surgery. J Surg Res, 2024; 293:607–612; doi: 10.1016/j.jss.2023.09.012

21.

Marin

, Ho

, Barnhart

, et al. Percutaneous abscess drainage in patients with perforated acute appendicitis: Effectiveness, safety, and prediction of outcome. AJR Am J Roentgenol, 2010; 194(2):422–429; doi: 10.2214/AJR.09.3098