Risk factors for poor outcomes in patients with acute lower leg compartment syndrome: a retrospective study of 103 cases.

PURPOSE: The primary aim of this study was to investigate the risk factors associated with poor outcomes following acute compartment syndrome (ACS) of lower leg. The secondary objective was to determine if delayed fasciotomy is linked to poor outcomes. METHODS: In this retrospective case control study approved by the institutional review board, we identified 103 patients with ACS of the lower leg. Poor outcome was defined as a composite variable that included limb amputation, neurological deficit and contracture. Among these, 44 patients exhibited poor outcome while 59 patients demonstrated a good outcome. Patient-related factors, laboratory values, and treatment-related factors were analyzed using electronic medical records. Univariate statistical and logistic regression analyses were conducted to determine significance. RESULTS: Bivariate analyses showed that the mechanism of injury (P = 0.021), open injury (P = 0.001), arterial injury (P<0.001), hemoglobin levels (HB) (P < 0.001), white blood cell count (WBC) (P = 0.008), albumin levels (ALB) (P<0.001), creatine kinase levels (CK) at presentation (P = 0.015), CK at peak (P<0.001), creatine kinase levels (Ca) (P = 0.004), dehydrating agent (P = 0.036), and debridement (P = 0.005) were found to be associated with the risk of poor outcomes. Logistic regression analyses revealed that arterial injury [ P< 0.001, OR = 66.172, 95% CI (10.536, 415.611)] was an independent risk factor for poor outcomes. However, HB [P = 0.005, OR = 0.934, 95% CI (0.891, 0.979)] was a protective factor against poor outcomes. Receiver operating characteristic (ROC) curve analysis showed that the cut-off values of HB to prevent poor outcome following ACS was 102.45 g/L. CONCLUSIONS: ACS of the lower leg is a serious complication often associated with a poor prognosis. Patients with arterial injury or lower HB have a significantly increased risk of having poor outcomes. Poor outcomes were not found to be associated with the timing of fasciotomy in this study.

Acute lumbar paraspinal compartment syndrome after radical cystectomy.

Lumbar paraspinal compartment syndrome (LPCS) is a rare diagnosis, seen in patients chronically after repeated lumbar trauma or acutely in a postoperative setting. Only a dozen cases are documented worldwide, and to date no clinical guidelines exist for the diagnosis nor the treatment.We describe the case of a 44-year-old man with excruciating lower back pain following a radical cystectomy. The postoperative laboratory values were compatible with acute rhabdomyolysis. The lumbar spine MRI showed necrosis of lumbosacral paraspinal muscles, making the diagnosis of acute LPCS. After seeking advice from different specialists, the conservative approach was chosen with combined pain treatment and physiotherapy. The patient is currently still disabled for some tasks and needs chronic pain medication.

The effect of time from injury to fasciotomy in patients with acute upper extremity compartment syndrome.

BACKGROUND: Acute compartment syndrome of the upper extremity is a surgical emergency, and timely diagnosis with immediate fasciotomies is essential for the preservation of function. This retrospective study aimed to compare the complication rates of patients who underwent fasciotomy before and after 6 hours following the initial trauma. METHODS: The medical records of the patients who underwent fasciotomy for surgical treatment of ACS of the upper extremity between 2016 and 2022 were retrospectively analyzed for age, gender, dominant hand, mechanism of injury, injury level, affected compartments, associated injuries, time elapsed till fasciotomy, and complications. The patients were divided into two groups according to the timing of fasciotomy. RESULTS: A total of 32 patients underwent fasciotomies for upper extremity ACS. The mean age of patients who underwent fasciotomy ≤ 6 hours (group 1; 10 males, 7 females) and patients who underwent fasciotomy > 6 hours (group 2; 13 males, 2 females) was 31.1 and 34.8, respectively. The most common etiology was crushing injury. There was a significant difference in complication rates between group 1 (1/17) and group 2 (10/15) (p<0.001). The length of hospitalization stay in group 2 was statistically higher than in group 1 (p=0.005). CONCLUSION: Fasciotomies for ACS of the upper extremity should be performed in less than 6 hours following the initial trauma to prevent complications.

Acute compartment syndrome of the thigh after total knee arthroplasty: a case report.

INTRODUCTION: Acute compartment syndrome of the thigh after total knee arthroplasty is a rarely described complication. After the assessment of the diagnosis, immediate surgical intervention is necessary to prevent further tissue damage. Since only a few cases have been described and because of the high complication rate, early detection is essential for ensuring patient outcomes. CASE PRESENTATION: After total knee arthroplasty in a high-volume university hospital, a 57-year-old Caucasian female patient experienced strong, disproportional pain in the ventromedial thigh of the affected leg, which did not respond to an adequate adjustment in pain medication. Imaging revealed a distinct swelling of the vastus intermedius muscle. This resulted in acute compartment syndrome of the thigh, which was immediately surgically treated. Apart from receiving surgery distal from the affected compartment and continuous intake of acetylsalicylic acid, the patient had no risk factors for developing compartment syndrome. The patient's recovery was uneventful, with timely wound closure and discharge to outpatient care without significant functional limitations. CONCLUSION: Acute compartment syndrome of the thigh represents a rare, but severe complication that can occur after orthopedic surgery. In our case, no triggering factors for the development of acute compartment syndrome, such as the use of a tourniquet, were detected. Even in unusual locations, compartment syndrome should be considered as a differential diagnosis. With sufficient evidence, immediate fasciotomy should be indicated.

Gluteal compartment syndrome: who is most at risk?

PURPOSE: Gluteal compartment syndrome (GCS) is a rare but devastating condition with a paucity of literature to help guide diagnosis and management. This study aims to identify and describe the risk factors and patient characteristics associated with GCS to facilitate early diagnosis. METHODS: This is a retrospective case series of patients undergoing gluteal compartment release between 2015 and 2022 at an academic Level I trauma center. Chart reviews were performed to extract data on patient demographics, presenting symptoms, risk factors, operative findings, and postoperative outcomes. RESULTS: 14 cases of GCS were identified. 12 (85.7%) were male, with a mean age of 39.4 ± 13 years and a mean BMI of 25.1 ± 4.1 kg/m2. 12 (85.7%) patients did not present as traumas and only 3 had ≥ 1 fracture. 9 patients reported drug use. Hemoglobin (Hgb) (11.7 ± 4 g/dL) was generally low (5 had Hgb < 10 g/dL). Creatine kinase (49,617 ± 60,068 units/L) was consistently elevated in all cases, and lactate (2.8 ± 1.6 mmol/L) was elevated in 9. 13 had non-viable muscle requiring debridement. Postoperatively, the mean ICU length of stay was 12 ± 23 days. 2 patients died during admission and all remaining patients required discharge to rehabilitation facilities. CONCLUSION: GCS is more likely to present in a young to middle-aged, otherwise healthy, male using drugs who is either found down or experienced an iatrogenic injury. Recognizing that GCS is different from that of the leg, in terms of etiology, may help avoid delays in diagnosis and treatment.

Olink proteomics analysis uncovers the landscape of inflammation-related proteins in patients with acute compartment syndrome.

Purpose: Our primary purpose was to explore the landscape of inflammation-related proteins, and our second goal was to investigate these proteins as potential biomarkers of acute compartment syndrome (ACS), which is a serious complication of tibial fractures. Methods: We collected sera from 15 healthy subjects (control group, CG) and 30 patients with tibial fractures on admission day, comprising 15 patients with ACS (ACS group, AG) and 15 patients without ACS (fracture group, FG). Ten samples in each group were analyzed by the inflammation panel of Olink Proteomics Analysis, and all samples were verified by an ELISA. Receiver-operating characteristic (ROC) curve analysis was performed to identify the diagnostic ability and cutoff values of potential biomarkers. Results: Our findings showed that the levels of IL6, CSF-1, and HGF in the FG were significantly higher than those in the CG. Similar results were found between the AG and CG, and their cutoff values for predicting ACS compared with the CG were 9.225 pg/ml, 81.04 pg/ml, and 0.3301 ng/ml, respectively. Furthermore, their combination had the highest diagnostic accuracy. Notably, compared with FG, we only found a higher expression of CCL23 in the AG. Additionally, we identified 35.75 pg/ml as the cutoff value of CCL23 for predicting ACS in patients with tibial fractures. Conclusion: We identified CCL23 as a potential biomarker of ACS in comparison with tibial fracture patients and the significance of the combined diagnosis of IL6, CSF-1, and HGF for predicting ACS compared with healthy individuals. Furthermore, we also found their cutoff values, providing clinicians with a new method for rapidly diagnosing ACS. However, we need larger samples to verify our results.

An uncommon complication of a common injury: Acute foot compartment syndrome following an ankle sprain: A case report and review of the literature.

INTRODUCTION: Acute foot compartment syndrome (FCS) is a rare but potentially devastating complication that can occur following severe trauma of the limbs. In very are cases, such syndrome occurs following minor trauma. We present an exceptional case of acute FCS as a complication of an ankle sprain. CLINICAL FINDINGS: A 32-year-old male patient presented with excruciating foot pain and swelling 48 hours following an ankle sprain. Physical examination revealed severe swelling of the right foot, pale and swollen toes, and tense and pale dorsal skin and severe pain upon passive extension of the toes. DIAGNOSIS: An acute FCS was considered. INTERVENTION AND OUTCOMES: The patient underwent a fasciotomy using a double-dorsal incision technique. The patient's symptoms were controlled, and he was discharged from the hospital 2 days after the surgery. CONCLUSION: Acute FCS could occur following minor trauma such as an ankle sprain. Early recognition and timely surgical intervention are crucial to prevent severe complications. The diagnosis is primarily clinical and immediate fasciotomy is needed to reduce intracompartment pressure and prevent muscular necrosis and other complications.

Lower Leg Lateral Chronic Exertional Compartment Syndrome: Prospective Surgical Treatment Outcomes for Isolated or Combined Lateral Fasciotomy.

BACKGROUND: Chronic exertional compartment syndrome involving the lower leg lateral compartment (lat-CECS) seldom occurs isolated but is usually combined with CECS of the anterior (ant-CECS) or deep posterior compartment (dp-CECS). Patient characteristics in lat-CECS and outcome after surgery are largely unknown. The aim of this prospective case series was to describe patient characteristics and symptoms and to report on outcome following a fasciotomy. METHODS: All patients diagnosed with lat-CECS based on exertional lateral lower leg symptoms and elevated intracompartmental pressure (ICP) measurements according to the Pedowitz criteria (ICP ≥ 15 mm Hg at rest, and/or ≥30 mm Hg after 1 minute, and/or ≥20 mm Hg 5 minutes after exercise) were eligible for this study. A standard intake questionnaire scoring symptom patterns was completed by all patients. Patients who were operated for lat-CECS were asked to complete a 3-month and 12-month postoperative questionnaire scoring symptoms and surgical outcome. Patients with a history of CECS surgery, recent lower leg trauma, or peripheral neurovascular disease were excluded. RESULTS: A total of 881 patients with possible lower leg CECS completed an intake questionnaire and 88 (10%) were diagnosed with lat-CECS according to the Pedowitz criteria (isolated lat-CECS n = 10; lat/ant CECS n = 54, lat/ant/dp CECS n = 19, lat/dp CECS n = 5). Severe pain during exercise and moderate tightness during rest were frequently reported. A group of 28 patients (49 legs; isolated lat-CECS n = 2; lat/ant CECS n = 22, lat/ant/dp CECS n = 3, lat/dp CECS n = 1) was analyzed after fasciotomy. Complications were minor (wound infection requiring antibiotics, n = 3; temporary complex regional pain syndrome with spontaneous recovery, n = 1). Superficial peroneal nerve damage was not observed. One year after surgery, 64% rated outcome as excellent or good, whereas 71% had resumed sports activities. CONCLUSION: One in 10 patients with anterolateral exertional lower leg pain evaluated in a tertiary referral center met diagnostic criteria for lat-CECS. Pain and tightness were present during exertion and were often reported occurring during rest and at night. In this series, we found fasciotomy-either an isolated (lateral) or a multiple (combined with anterior and/or deep posterior) compartment fasciotomy-is safe and beneficial in most patients. LEVEL OF EVIDENCE: Level IV, case series.

Atypical compartment syndrome of the forearm due to mixed infection with Proteus mirabilis and Morganella morganii after a penetrating injury: A limb-saving approach.

Compartment syndrome is a well-described clinical condition and is considered an orthopedic emergency affecting individuals of all ages. A typical scenario for acute compartment syndrome involves lower limb fractures or crush injuries. However, physicians may occasionally encounter atypical presentations, defined as atypical compartment syndrome (ACS). A 38-year-old, left-handed male patient without any comorbidities developed ACS of the forearm and clinical presentation of sepsis after a small penetrating injury to his right forearm. He developed ACS secondary to infected hematoma and subsequent soft tissue infection caused by Proteus mirabilis and Morganella morganii. Both bacteria infected the patient by direct contamination after injury with a knife, resulting in multifloral contamination. The patient was successfully treated with reconstructive surgery. In conclusion, ACS secondary to this type of penetrating injury shows a subtle clinical course at the time of hospital admission and can insidiously progress from an infected hematoma, posing a serious threat to the limb or even cause mortality. Good extremity function without any disability can be achieved with an accurate diagnosis during the initial evaluation of the patient in the emergency department and prompt surgical intervention followed by appropriate reconstructive methods.

Evaluation of musculoskeletal injuries after the 2023 Kahramanmaras earthquake: A local hospital experience.

OBJECTIVES: The aim of this study was to evaluate musculoskeletal injuries, clinical follow-ups and treatments of trauma patients admitted to our hospital after the 2023 Kahramanmaras earthquake. PATIENTS AND METHODS: Between February 6th, 2023 and February 16th, 2023, a total of 957 trauma patients (452 males, 505 females; mean age: 36.2±19.9 years; range, 0 to 97 years) who were affected by the earthquake were retrospectively analyzed. Age, sex, presence of orthopedic consultation, diagnosis of open/closed fracture, diagnosis of dislocation, presence and classification of soft tissue injury, additional system injury, preoperative and postoperative neurovascular examination status, presence of compartment syndrome, conservative/surgical applications, operation side, fasciotomy surgery and level, amputation surgery and level, length of stay in the hospital and intensive care unit (ICU), the Mangled Extremity Severity Score (MESS) score were collected. RESULTS: A total of 811 of the survivors were Turkish and 146 were Syrians. Of 957 earthquake victims, 40% had soft tissue injuries, 19% had closed fractures, 8.9% had other system injuries, 7.7% had crush injuries, 4.1% had nerve injuries, 2.1% had compartment syndrome, 2.1% had vascular injury, 1.8% had dislocation, and 1.7% had open fracture. Surgical or conservative treatments were applied to 574 patients with musculoskeletal injuries. Conservative treatment was applied to 322 of 574 patients and surgical procedure was applied to 252 patients. CONCLUSION: The highest patient density is experienced within the first 24 h after a devastating earthquake. The most common injuries due to high-energy trauma are isolated soft tissue injuries and fractures. The definition of the demographic characteristics and clinical outcomes of earthquake patients is critical to the development of preparedness, response, and recovery policies for future disasters..

Chronic Exertional Compartment Syndrome Resolved With Running Gait Retraining: A Case Report.

A 34-year-old female athlete experienced pain, tightness, and sensation changes in her lower legs and feet when reaching approximately 1 mile (1.6 km) of her run. After a wick catheter test, an orthopaedic surgeon diagnosed her with chronic exertional compartment syndrome (CECS) and declared her eligible to undergo fasciotomy surgery. A forefoot gait is theorized to delay the symptom onset of CECS and decrease the amount of discomfort the runner experiences. The patient opted for a 6-week gait retraining program to try to alleviate her symptoms nonsurgically. The purpose of our report is to provide information about the contributing factors of CECS and to determine if gait retraining is an effective alternative to invasive surgery. After 6 weeks of gait retraining, the patient was able to run without experiencing any CECS symptoms. Also, her compartment pressures were reduced, leading the surgeon to no longer recommend fasciotomy.

Management of Chronic Exertional Compartment Syndrome of the Foot: A Report of 3 Cases.

BACKGROUND: Arch pain in athletes is a common complaint with many causes. One uncommon cause of arch pain related to exercise that is often overlooked is chronic exertional compartment syndrome. This diagnosis should be considered in athletes who presents with exercise-induced foot pain. Recognition of this problem is paramount because it can significantly affect an athlete's ability to pursue further sports activities. METHODS: Three case studies are presented that underscore the importance of a comprehensive clinical evaluation. Unique historical information and findings on focused physical examination after exercise strongly suggest the diagnosis. RESULTS: Intracompartment pressure measurements before and after exercise are confirmatory. Because nonsurgical care is typically palliative, surgery involving fasciotomy to decompress involved compartments can be curative and is described in this article. CONCLUSIONS: These three cases with long-term follow-up were randomly chosen and are representative of the authors' combined experience with chronic exertional compartment syndrome of the foot.

Lateral Compartment Syndrome From Inversion Injury.

A 17-year-old male presented for the evaluation of right calf pain after an inversion ankle sprain sustained while playing soccer 24 hours prior. On exam, he exhibited swelling and tenderness to palpation over his right calf, mild first web space numbness, and compartment pressures <30 mmHg. Magnetic resonance imaging was significant for findings of lateral compartment syndrome (CS). Upon admission, his exam worsened, prompting an anterior and lateral compartment fasciotomy. Intraoperative findings were significant for lateral CS, with findings of avulsed, nonviable muscle with associated hematoma. Postoperatively the patient had mild foot drop, which improved with physical therapy. Lateral CS rarely develops from an inversion ankle sprain. This presentation of CS is unique due to its mechanism, delayed clinical presentation, and limited signs of CS. Providers should maintain a high index of suspicion for CS in patients with this injury complex and continued pain beyond 24 hours without signs of ligamentous injury.

Efficacy of a portable interface pressure sensor for robotic surgery in preventing compartment syndrome.

BACKGROUND/OBJECTIVE: This study determines whether the use of a portable interface pressure sensor (Palm Q) for robotic surgery could prevent compartment syndrome. METHODS: In the present single center, non-trial observational study, patients diagnosed with gynecological diseases between April 2015 and August 2020 treated with laparoscopic or robotic surgery were enrolled. We assessed 256 cases involving surgery performed in the lithotomy position with an operative time >4 h. The Palm Q device was placed preoperatively on both sides of the patients' lower legs. The pressure was measured every 30 min preoperatively and intraoperatively and adjusted to ≤30 mmHg. If the pressure reached ≥30 mmHg, the operation was stopped, the patient was repositioned, the leg position was released, the pressure was reduced to ≤30 mmHg, and the procedure was resumed. We compared the maximum creatine kinase levels of the Palm Q and non-Palm Q groups. We also analyzed the correlation between the patients' symptoms postoperatively (shoulder and leg pain) and compartment syndrome. RESULTS: Our data showed that immediate postoperative creatine kinase levels predict compartment syndrome. Propensity score matching of the 256 enrolled patients resulted in 92 cases (46 per group), balanced for age, body mass index, and lifestyle disease. Creatine kinase levels differed significantly between the Palm Q and non-Palm Q groups (p = 0.041). None of the patients in the Palm Q group experienced well-leg compartment syndrome complications. CONCLUSION: Palm Q can potentially help to prevent perioperative compartment syndrome.

Necessity, Role, and Outcomes of Fasciotomy in Patients with Acute Limb Ischemia.

BACKGROUND: The incidence of compartment syndrome in patients with acute lower limb ischemia (ALLI) and the effects of fasciotomy on outcomes are largely undefined. This study aimed to define the incidence of compartment syndrome in patients with ALLI and to examine whether different fasciotomy strategies are associated with specific patient outcomes. METHODS: A single-center retrospective study of patients who had ALLI between April 2016 and October 2020 at a tertiary care center. Patients were categorized into groups as having received early and late therapeutic fasciotomy (TF), early prophylactic fasciotomy (PF), early exploratory fasciotomy, and no fasciotomy. Primary outcome was 30-day amputation rate. Secondary outcomes were 30-day and 1-year mortality, 1-year amputation rate, and length of stay. Groups were compared using descriptive statistics to assess the association of fasciotomy approach with outcomes. RESULTS: During the study period, 266 patients were treated for ALLI, and 62 patients (23%) underwent 66 fasciotomies. A total of 41 TF, 23 PF, and 2 exploratory fasciotomies were done. There were 58 early fasciotomies performed (88% of 66 limbs): 33 (57%) early TF, 23 (40%) PF, and 2 (3%) exploratory. There were 8 patients who developed compartment syndrome after their revascularization operation and received delayed TF (12% of 66 limbs). The total number of TF was 41, which was 15% of all ALLI patients. The mean ± SD time to fasciotomy closure was 6.7 ± 5.7 days, which did not differ between PF and TF groups. Significantly more patients in the TF group had an amputation at 30 days (11 [29%] vs. 1 [5%]; P = 0.03) and at 1 year (6 [18%] vs. 2 [9%]; P = 0.02) than those in the PF group. Length of stay was increased in both TF (16 days) and PF (19 days) patients compared to nonfasciotomy patients (10 days; P < 0.01) but did not differ between the 2 fasciotomy groups (P = 0.4). Thirty-day limb loss was highest in patients who underwent early TF (10/33, 33%), intermediate in those with delayed TF (1/8, 13%), and lowest in PF (1/23, 5%; P = 0.03). CONCLUSIONS: Approximately 15% of patients with ALLI in our cohort required a TF for compartment syndrome. Close postoperative monitoring of ALLI patients who did not undergo early fasciotomy did detect delayed compartment syndrome; however, this approach did not prevent limb loss. To optimize limb salvage, physicians treating patients with ALLI should be experienced in how to recognize and treat compartment syndrome.

Atraumatic Acute Paraspinal Compartment Syndrome in a Patient With McArdle's Disease.

A 60-year-old male presented to the emergency room with complaints of back pain overlying the left lumbar area and ipsilateral thigh numbness. The left erector spinae musculature was rigid, tense, and painful to palpation. An elevated serum creatine kinase was identified, and a computed tomography scan showed evidence of left paraspinal musculature congestion. Past medical/surgical history was significant for McArdle's disease and bilateral forearm fasciotomies. The patient underwent lumbosacral fasciotomy with no obvious myonecrosis. The patient was discharged home after skin closure and has since been seen in clinic with no residual pain or change in baseline functional status. This case may represent the first reported atraumatic exertional lumbar compartment syndrome in a patient with McArdle's disease. Prompt operative intervention was effective in this case of acute atraumatic paraspinal compartment syndrome and resulted in an excellent functional outcome.

Predictors for surgical site infection after fasciotomy in patients with acute leg compartment syndrome.

BACKGROUND: Surgical site infection (SSI) is one of the most common complications of orthopedic surgery, which can result in fever, pain, and even life-threatening sepsis. This study aimed to determine the predictors of SSI after fasciotomy in patients with acute leg compartment syndrome (ALCS). METHODS: We collected information on 125 ALCS patients who underwent fasciotomy in two hospitals between November 2013 and January 2021. Patients with SSI were considered as the SSI group and those without SSI as the non-SSI group. Univariate analysis, logistic regression analysis, and receiver operating characteristic (ROC) curve analyses were used to evaluate patient demographics, comorbidities, and admission laboratory examinations. RESULTS: In our research, the rate of SSI (26 of 125) was 20.8%. Several predictors of SSI were found using univariate analysis, including body mass index (BMI) (p = 0.001), patients with open fractures (p = 0.003), and patients with a history of smoking (p = 0.004). Besides, the levels of neutrophil (p = 0.022), glucose (p = 0.041), globulin (p = 0.010), and total carbon dioxide were higher in the SSI group than in the non-SSI group. According to the results of the logistic regression analysis, patients with open fractures (p = 0.023, OR 3.714), patients with a history of smoking (p = 0.010, OR 4.185), and patients with a higher BMI (p = 0.014, OR 1.209) were related predictors of SSI. Furthermore, ROC curve analysis indicated 24.69 kg/m2 as the cut-off value of BMI to predict SSI. CONCLUSIONS: Our results revealed open fractures, BMI, and smoking history as independent risk factors for SSI following fasciotomy in patients with ALCS and determined the cut-off value of BMI, enabling us to individualize the evaluation of the risk for SSI to implement early targeted treatments.

Incidence and Mortality of Pediatric Abdominal Compartment Syndrome.

INTRODUCTION: Abdominal compartment syndrome (ACS) is the presence of intra-abdominal hypertension with systemic, multiorgan effects and is associated with high mortality, yet the national incidence and mortality rates of pediatric ACS remain unknown. The aim of this study is to evaluate the incidence and mortality of pediatric ACS over a 13-year period across multiple children's hospitals and between individual children's hospitals in the United States. METHODS: We performed a retrospective cohort study on children (aged < 18 y) with ACS in the Pediatric Health Information Systems database from 2007 to 2019. We identified ACS patients by International Classification of Diseases codes in the ninth and 10th revision. The primary outcomes were incidence and mortality, which were analyzed by year, age, and hospital of admission. RESULTS: Across 49 children's hospitals, we identified 2887 children with ACS from 2007 to 2019 in the Pediatric Health Information Systems database. The overall incidence of ACS was 0.17% and the overall mortality was 48.87%. There was no significant difference in annual incidence (P = 0.12) or mortality (P = 0.39) over the study period. There was no difference in incidence across age group (P = 0.38); however, mortality in patients 0-30 d old (58.61%) was significantly higher than older age groups (P < 0.0001). The hospital-specific incidence (0.04%-0.46%) and mortality (28.57%-71.43%) varied widely. CONCLUSIONS: The annual incidence and mortality of pediatric ACS are unchanged from 2007 to 2019. ACS mortality remains high, especially in neonatal intensive care unit patients. No obvious correlation is seen between incidence rates and mortality. Differing hospital-specific incidence and mortality could suggest inconsistencies between institutions that affect pediatric ACS care, perhaps with respect to recognition and diagnosis.