Acuity of Patients Undergoing Congenital Heart Surgery During Hospitalization

Abstract

Background

Since 2014, Complexity Assessment and Monitoring to Ensure Optimal Outcomes (CAMEO) acuity tools have guided pediatric critical care and acute nurse staffing decisions. Using these data, we constructed a cardiac intensive care postoperative timeline, the CAMEO Acuity Curve, for 3 congenital heart surgery procedures. We now expand both procedures and timeline to comprehensively describe patient acuity during hospitalization.

Methods

We reviewed 5 common congenital heart procedures between November 2018 and December 2023—Stage I palliation for single ventricle, arterial switch operation for dextro transposition of great arteries with or without ventricular septal defect repair, tetralogy of Fallot repair, ventricular septal defect repair, and atrial septal defect repair. CAMEO scores from cardiac intensive care unit admission through discharge were abstracted to create procedure‐specific CAMEO Acuity Curves. Data were also stratified by severity of residual lesions in anatomic area of repair using the residual lesion score.

Results

Among 574 cases, 72 (13%) were Stage I, 118 (20%) arterial switch operation repair, 144 (25%) tetralogy of Fallot repair, 159 (28%) ventricular septal defect repair, and 81 (14%) atrial septal defect repair. CAMEO scores varied in acuity by procedure. The highest mean acuity was for Stage I (116±6) and the lowest for atrial septal defect repair (94±9). Acuity increased for residual lesion score 3 compared with residual lesion score 1 and 2.

Conclusions

CAMEO Acuity Curves for 5 postoperative congenital heart procedures illustrate expected periods of high acuity. This approach highlights variation by procedure, physiologic status, and hemodynamically significant residual lesions and may inform timely clinical decision‐making, guide acuity‐specific interprofessional staffing, facilitate throughput, and predict resource needs.

Nonstandard Abbreviations and Acronyms

ACCU

acute care cardiac unit

ASO

arterial switch operation

CAMEO

Complexity Assessment and Monitoring to Ensure Optimal Outcomes

CICU

cardiac intensive care unit

RLS

residual lesion score

TOF

tetralogy of Fallot repair

Clinical Perspective.

What Is New?

• This study expands the novel application of Complexity Assessment and Monitoring to Ensure Optimal Outcomes data to create Acuity Curves for patients undergoing congenital heart surgery and demonstrates the feasibility and utility of constructing Complexity Assessment and Monitoring to Ensure Optimal Outcomes Acuity Curves for 5 procedures—Stage I palliation, arterial switch operation repair, tetralogy of Fallot repair, ventricular septal defect repair, and atrial septal defect repair—with residual lesion score class stratification identifying higher acuity trends based on adequacy of surgical repair.

What Are the Clinical Implications?

• Complexity Assessment and Monitoring to Ensure Optimal Outcomes Acuity Curves help to identify when increased surveillance and possibly intervention may be necessary, ensuring that both immediate and long‐term care needs are communicated across the clinical team and integrated into patient care, while supporting evidence‐based staffing and offering a framework for measuring patient acuity and the diverse needs of pediatric patients during hospitalization.

• The development of procedure‐specific Complexity Assessment and Monitoring to Ensure Optimal Outcomes Acuity Curves illustrates expected periods of high acuity throughout the hospitalization experience and variation in acuity by surgical procedure and patient surgical status, which may be used to inform timely clinical decisions, assessment of interprofessional staffing requirements, facilitate throughput, and project resource needs for providing optimal care for children undergoing cardiac surgery.

Children with congenital heart disease often require surgical intervention during the first days or early years of life. ¹ , ² Specialized interprofessional teams provide pre‐ and postoperative management of these patients in intensive or acute care settings. ³ Outcomes for this hospitalization period are typically evaluated by mortality, morbidity and resource use. ⁴ , ⁵ , ⁶ , ⁷ , ⁸ Factors influencing these outcomes include preoperative clinical status, case complexity, adequacy of surgical repair, and postoperative complications. ⁹ , ¹⁰ , ¹¹ , ¹² , ¹³ , ¹⁴ The acuity of patients undergoing congenital heart surgery and its role in indicating physiological perturbations associated significant residual lesions has not been characterized.

The Complexity Assessment and Monitoring to Ensure Optimal Outcomes (CAMEO) acuity tool, developed in 2009, quantifies domains and attributes of patient acuity. ¹⁵ This patient acuity is assessed by the direct care nurse each shift. Through shift‐to‐shift documentation, we noted the dynamic nature of CAMEO acuity across case complexity and postoperative periods. ¹⁶ To demonstrate this concept, we aggregated CAMEO scores for a cohort of cases admitted for three cardiac surgeries, forming procedure‐specific acuity curves. ¹⁶ We also found that acuity increases as severity of residual lesion increases, as assessed by the residual lesion score (RLS). ¹⁶

Development of CAMEO Acuity Curves presented a postoperative timeline of patient acuity in the cardiac intensive care unit (CICU). ¹⁶ We now extend this methodology to 5 surgeries, examining acuity in both the CICU and acute care cardiac unit (ACCU) with a larger patient cohort.

METHODS

Because of its sensitive nature, the data that support the findings of this study will not be made available.

Study Design and Population

This is a single‐site retrospective cohort study conducted at a heart center in a free‐standing children's hospital in the Northeast United States. The center includes a 44‐bed CICU and 52‐bed ACCU, specializing in congenital and acquired cardiac disease. We included patients admitted to the CICU for Stage I palliation for single ventricle, arterial switch operations (ASO) for dextro transposition of great arteries with or without ventricular septal defect (VSD) closure, tetralogy of Fallot repair (TOF), isolated VSD repair, and isolated atrial septal defect repair (ASD) between November 2018 and December 2023.

Data Collection

Upon institutional review board approval (IRB‐P00035223), we initiated a retrospective review of CICU admissions for 1 of 5 congenital heart procedures. A waiver of consent was granted, considering the retrospective nature of the data collection and that there is no planned intervention. Patients were identified from the institutional cardiac surgical database and reviewed for inclusion/exclusion criteria following procedure‐specific guidelines (Table 1).

Table 1.

Procedure‐Specific Inclusion/Exclusion Criteria

Procedure	Inclusion criteria	Exclusion criteria
Stage I palliation for single ventricle	Any single ventricle anatomy only neonates (STAT mortality category 5)	Those subjects who underwent hybrid and subsequent comprehensive stage II procedure
ASO	dTGA (STAT mortality category 3 for ASO, 4 for ASO+VSD)	dTGA/intact ventricular septum or dTGA/VSD with hypoplastic arch and noncommitted VSDs Taussig Bing anomaly
TOF	Neonates and infants Can include valve sparing repair or transannular repair with or without monocusp valve (STAT mortality category 1 if valve sparing repair and 2 if transannular patch repair)	Isolated TOF/pulmonary stenosis requiring right ventricle to PA conduit TOF/PA with duct‐like collaterals TOF/PA/major aortopulmonary collateral arteries TOF/absent pulmonary valve TOF complete atrioventricular canal Prior ductal stent Prior pulmonary valve balloon dilation or right ventricular outflow tract stent
VSD	Neonates and infants (STAT mortality category 1) Can include ASD/PFO closure, PDA ligation, TV take down and reattachment, or TV commissuroplasty as part of VSD repair	Associated complex intracardiac anatomy where future intracardiac repair is planned VSD repair as part of staged repair for Arch/VSD with prior arch repair via a thoracotomy Prior PA band Multiple VSDs Any residual VSDs
ASD	Neonates and infants and children (STAT mortality category 1) Can include PFO closure, PDA ligation	ASD performed as concomitant procedure as part of more complex multicomponent procedure.

ASD indicates atrial septal defect; ASO, arterial switch operation for dextro transposition of great arteries with or without ventricular septal defect repair; dTGA, d‐transposition of the great arteries; PA, pulmonary artery; PDA, patent ductus arteriosus; PFO, patent foramen ovale; STAT, Society of Thoracic Surgeons Congenital Heart Surgery Database Anesthesia Tool; TOF, tetralogy of Fallot repair; TV, tricuspid valve; and VSD, ventricular septal defect repair.

Variables

We abstracted demographic, clinical, CICU management, and operative data from the hospital's electronic medical record and cardiac surgical database. Demographics included age and weight on day of surgical procedure. Clinical characteristics contained genetic disorders and comorbidities using the Society of Thoracic Surgeons Congenital Heart Surgery Database preoperative risk factors. ¹¹ CICU management variables included preoperative vasoactive use or ventilation. Operative variables comprised cardiopulmonary bypass time, delayed sternal closure and postoperative cardiopulmonary arrest. Length of stay (LOS) was reported for CICU, ACCU, and total hospital stay.

CAMEO Tool

The CAMEO measures acuity by quantifying nursing cognitive workload complexity, which involves processing patient information to drive critical thinking, decision‐making, and the resulting level of surveillance to meet the comprehensive needs of patients and their families. ¹⁵ , ¹⁷ , ¹⁸ The ICU CAMEO and Inpatient CAMEO consist of 10 domains of care, contributing to a baseline total score of 54 for the ICU and 57 for the Inpatient, to a high of 228. ¹⁵ , ¹⁹ Scores are categorized from Level I (lowest) to Level V (highest) using the ICU or Inpatient CAMEO Complexity Classification System, which guides the level of nursing surveillance (Figure 1). ¹⁵ , ²⁰ , ²¹ Validated in 2020 across 9 US children's hospitals, the CAMEO significantly correlated with the Therapeutic Intervention Scoring System‐Children and the Pediatric Risk of Mortality III, using 840 patients admitted to 1 of 15 ICUs (CICUs and mixed pediatric ICUs). ²¹ This study confirmed the utility of a standardized acuity measure to guide staffing decisions and benchmarking. ²¹

Figure 1. Percentage of admission days with CAMEO complexity classification level IV or V, by procedure type.

ACCU indicates acute care cardiac unit; ASD, atrial septal defect; ASO, arterial switch operation for dextro transposition of great arteries with or without ventricular septal defect repair; CAMEO, Complexity Assessment and Monitoring to Ensure Optimal Outcomes; CICU, cardiac intensive care unit; Stage I, Stage I palliation for single ventricle; TOF, tetralogy of Fallot repair; and VSD, ventricular septal defect repair.

To develop the CAMEO Acuity Curves, we abstracted CAMEO scores for each shift from CICU admission to hospital discharge. If a CAMEO score was missing for a shift, the clinical nursing lead and principal investigator reviewed the documented nursing care and the score from the preceding and following shifts to estimate it.

Residual Lesion Score

The RLS for cases was obtained from the cardiovascular surgical database. RLS is a quality improvement tool that assesses adequacy of repair for each anatomic subcomponent using echocardiographic and clinical criteria. It is validated for >90% of all congenital cardiac procedures. ²² The RLS categorizes each subcomponent of a congenital cardiac operation into 3 classes: Class 1—optimal (trivial or no residual lesions); Class 2—adequate (minor residual lesions); Class 3—inadequate (major residual lesions or need for reintervention for major residual lesions before discharge from index surgery). The overall RLS for each procedure is calculated based on subcomponent scores. A procedure is RLS Class 1 if all subcomponents are Class 1, Class 2 if ≥1 subcomponent scores are Class 2 but none are Class 3, and Class 3 if any subcomponents are Class 3. At our center, RLS is calculated for each surgical patient intraoperatively and before discharge.

Statistical Analysis

Patient characteristics were summarized using frequencies and percentages for categorical variables and medians with interquartile ranges for continuous variables. CAMEO scores were summarized with means±SD across CICU, ACCU, and total hospital days. All analyses were stratified by procedure type. Procedure‐specific CAMEO Acuity Curves were created by plotting daily mean scores as line graphs that extended to the median hospital LOS for that procedure. Curves were also stratified by RLS Class 1 and 2 versus RLS Class 3; for this comparison, patients for whom RLS was not calculated because of incomplete echocardiographic data were excluded. The proportion of hospital days overall and in the CICU and ACCU, which had a CAMEO Complexity Classification of level IV or V, was determined. Analyses were performed in Stata version 17. ²³

RESULTS

Demographic Clinical Variables

A total of 574 cases were reviewed: Stage I (n=72, 13%), ASO (n=118, 20%), TOF (n=144, 25%), VSD (n=159, 28%), and ASD (n=81, 14%). Table 2 summarizes demographic, clinical, CICU management and operative data. Most patients with Stage I and ASO underwent surgery within days of life, with TOF and VSD cases between 1 and 6 months and ASD cases at a median of 3.4 years. The median weight was lowest for Stage I and ASO (3.3 kg) followed by TOF and VSD (4.7 kg) and ASD (13.5 kg). Proportions of patients with a known genetic abnormality or noncardiac congenital anomaly varied with VSD having the highest (31%) frequency. Preoperative risk factors were highest in ASO cases (65%), which also coincided with vasoactive medications (28%) and ventilation (20%) before surgery. The median pump time was highest for Stage I cases at 205 minutes. Stage I cases had the longest days of ventilation (8 days), highest frequency of delayed sternal closure (76%) and postoperative cardiopulmonary arrest (4%). Hospitalization in number of days was highest in Stage I cases (total days 44, CICU 24, ACCU 14) and lowest in ASD (total days 3, CICU 1, ACCU 3). When stratified by RLS class, the cases ranged in assessment of RLS Class 1 and 2 with Stage I=70% to ASD=99%.

Table 2.

Patient and Procedure Characteristics, by Procedure Type^*

	Stage I palliation for single ventricle	ASO	TOF	VSD	ASD
Number of patients	72	118	144	159	81
Age at surgery	3 (3–5) d	4 (3–5) d	3.1 (1.9–4.4) mo	3.3 (2.0–5.8) mo	3.4 (2.1–4.4) y
Weight at surgery, kg	3.3 (3.0–3.6)	3.3 (3.0–3.6)	4.9 (3.9–5.9)	4.7 (3.6–6.0)	13.5 (10.3–16.8)
Any genetic disorder	15 (21%)	15 (13%)	43 (30%)	50 (31%)	11 (14%)
Any comorbidity	19 (26%)	77 (65%)	23 (16%)	31 (20%)	19 (23%)
Vasoactives before surgery	5 (7%)	33 (28%)	7 (5%)	0 (0%)	2 (2%)
Pump time, min	205 (172–252)	192 (169–225)	136 (119–169)	97 (79–113)	50 (43–57)
Ventilation before surgery	2/72 (3%)	24/118 (20%)	3/144 (2%)	3/159 (2%)	2/81 (2%)
Total ventilation time, d	8 (6–14)	3 (2–5)	1 (1–2)	1 (0–2)	0 (0–0)
Delayed sternal closure	55/72 (76%)	24/118 (20%)	12/144 (8%)	2/159 (1%)	0/81 (0%)
Cardiopulmonary arrest	3/72 (4%)	1/118 (1%)	1/144 (1%)	1/159 (1%)	0/81 (0%)
Cardiac intensive care unit length of stay, d	24 (15–49)	10 (7–16)	4 (2–10)	3 (1–10)	1 (1–1)
Acute care cardiac unit length of stay, d	14 (6–24)	9 (6–12)	4 (3–7)	4 (3–7)	2 (2–3)
Total length of stay, d	44 (31–64)	19 (15–27)	9 (6–16)	7 (5–18)	3 (3–4)
Residual lesion score†
1	45 (63%)	68 (58%)	69 (48%)	110 (69%)	79 (98%)
2	5 (7%)	36 (31%)	59 (41%)	45 (28%)	1 (1%)
3	14 (19%)	13 (11%)	16 (11%)	45 (28%)	0 (0%)
Not assigned	8 (11%)	1 (1%)	0 (0%)	1 (1%)	1 (1%)

^*Values shown are number (percentage) or median (25th–75th percentiles).

^† Residual lesion score category percentages (1, 2, 3, and not assigned) are rounded independently; therefore, totals may exceed 100%.

ASD indicates atrial septal defect; ASO, arterial switch operation for dextro transposition of great arteries with or without ventricular septal defect repair; TOF, tetralogy of Fallot repair; and VSD, ventricular septal defect repair.

CAMEO Scores

As displayed in Table 3, Stage I cases had the highest mean total hospital CAMEO score (116±6). ASO cases also showed an increased mean total hospital CAMEO score of 103±8. The mean total hospital CAMEO mean scores were similar for TOF (98±9), VSD (97±9), and ASD (94±9) cases. The CICU CAMEO mean score was again highest for Stage I cases (116±6) and lowest for ASD cases (108±15). The ACCU CAMEO mean score for Stage I matched the CICU CAMEO mean score, 116±6, whereas the other 4 cohorts in the ACCU were >20 points lower.

Table 3.

CAMEO Scores^*, by Procedure Type ^†

	Stage I palliation for single ventricle	ASO	TOF	VSD	ASD
Number of patients	72	118	144	159	81
Overall mean CAMEO score across total hospital length of stay	116±6	103±8	98±9	97±9	94±9
Overall mean CAMEO score across CICU length of stay	116±6	114±9	111±13	110±14	108±15
Overall mean CAMEO score across ACCU length of stay	116±6	86±5	88±6	87±7	85±6
Number of patients by RLS
1+2	50 (69%)	104 (88%)	128 (89%)	155 (97%)	80 (99%)
3	14 (19%)	13 (11%)	16 (11%)	3 (2%)	0 (0%)
RLS 1+2: Overall mean CAMEO score across total hospital length of stay	116±6	102±7	97±8	97±9	94±9
RLS 1+2: Overall mean CAMEO score across CICU length of stay	115±6	114±9	111±13	110±14	108±15
RLS 1+2: Overall mean CAMEO score across ACCU length of stay	115±6	86±5	88±6	87±6	85±6
RLS 3: Overall mean CAMEO score across total hospital length of stay	119±6	109±12	105±11	101±9	NA
RLS 3: Overall mean CAMEO score across CICU length of stay	120±7	115±9	116±12	108±8	NA
RLS 3: Overall mean CAMEO score across ACCU length of stay	116±5	87±6	92±5	95±9	NA

^*Values shown are mean±SD.

^† Residual lesion score category percentages (1–3) are rounded independently and therefore may not equal 100%.

ACCU indicates acute care cardiac unit; ASD, atrial septal defect; ASO, arterial switch operation for dextro transposition of great arteries with or without ventricular septal defect repair; CAMEO, Complexity Assessment and Monitoring to Ensure Optimal Outcomes; CICU, cardiac intensive care unit; NA, not applicable; RLS, residual lesion score; TOF, tetralogy of Fallot repair; and VSD, ventricular septal defect repair.

When stratified by RLS Class, the total hospital CAMEO mean score for RLS Class 3 cases had a higher mean for the total hospital stay as compared with RLS Class 1 and 2 cases (Stage I, 119±6, ASO, 109±12, TOF, 105±11, and VSD, 101±9). The CICU CAMEO scores for Stage I, ASO, and TOF were higher than RLS Class 1 and 2 cases. The CICU CAMEO score for VSD RLS Class 3 cases (108±8) was 2 points lower (110±14). The ACCU CAMEO scores for RLS Class 3 cases were higher for all 4 procedures as compared with RLS 1 and 2 cases with the VSD noted to be 8 points higher (Table 3).

CAMEO Acuity Curves

Figure 2 shows the CAMEO Acuity Curves by surgical procedure. On Day 1 of CICU admission, TOF, VSD, and ASD cases had the highest overall mean CAMEO score as they were postoperative at time of admission. Patients requiring ASO repair experienced increased acuity on Day 1 due to stabilization management through balloon septostomy and ventilation, which decreased until surgery on Day 4. For Stage I cases, the CAMEO Acuity Curve rises on Day 3, which correlates with timing of surgical palliation.

Figure 2. CAMEO acuity curves, by procedure type and residual lesion score.

A, Stage I palliation for single ventricle; B, ASO; C, TOF; D, VSD; E, ASD. ^§§Stratified acuity curves for ASD could not be constructed due to lack of RLS 3 cases. ASD indicates atrial septal defect; ASO, arterial switch operation for dextro transposition of great arteries with or without ventricular septal defect repair; CAMEO, Complexity Assessment and Monitoring to Ensure Optimal Outcomes; RLS, residual lesion score; TOF, tetralogy of Fallot repair; and VSD, ventricular septal defect repair.

Stage I

The CAMEO Acuity Curve for Stage I palliation spans a 44‐day median hospital LOS (Figure 2). Scores peak on Day 6 with a mean of 127, reflecting CICU management involving titration of vasoactive and fluid drips, surgical closure of chest, and weaning of the ventilator. Although acuity decreases post peak, high levels persist throughout hospitalization, indicating complex clinical care after transfer from the CICU to the ACCU. From Day 28, beyond the 24‐day median CICU LOS, acuity spikes reflect ACCU care focus on Home Monitoring Program enrollment, complex discharge planning, family education, and ongoing clinical management. ²⁴

Stratifying CAMEO scores by RLS Class 1 and 2 versus RLS Class 3 shows a general increase in mean score for RLS Class 3 cases from Day 10, with some overlap, persisting through most of hospitalization (Figure 2). This indicates early RLS status and correlates with median extubation time and inability to tolerate decreasing clinical support.

Arterial Switch Operation

For ASO, the CAMEO Acuity Curve extends over a 19‐day median hospital LOS (Figure 2), peaking on Day 6 with a mean score of 121. Postoperative care is primarily focused on achieving hemodynamic stability through ventilation, vasoactive drips, and fluid management, as fewer had delayed sternal closure (20%). After the peak, acuity decreases for RLS Class 1 and 2 cases. However, RLS Class 3 cases maintained higher mean CAMEO scores throughout hospitalization (Figure 2).

TOF Repair

For TOF repair, the CAMEO Acuity Curve covers a 9‐day median hospital LOS (Figure 2), peaking on Day 1 of CICU admission with a mean score of 116. This reflects the immediate postoperative period, consistent with frequent assessments, maintenance of hemodynamic stability through fluid and vasoactive titration, and steps toward extubation. Acuity decreased for RLS Class 1 and 2 cases until Day 7, then gradually increased, likely due to increase in transfer‐related complexity. Of note, 30% had a genetic disorder and 16% had comorbidities, necessitating coordination of care, discharge planning, and education. Despite postoperative acuity decline, RLS Class 3 cases maintain higher mean scores, with increases from days 3 to 6 (Figure 2).

VSD Repair

For VSD repair, the CAMEO Acuity Curve spans a 7‐day median hospital LOS (Figure 2), peaking on Day 1 of CICU admission with a mean score of 122, the highest across the 5 procedures. This signals the immediate postoperative period with frequent assessments, maintenance of hemodynamic stability via fluid and vasoactive titration, or postextubation. After the first 24 hours, acuity steadily decreased for RLS Class 1 and 2 cases until Day 5, then gradually increased. Notably 31% had a genetic disorder, and 20% had comorbidities, necessitating complex care coordination. Despite postoperative acuity decline, RLS Class 3 cases maintained higher mean scores, with increases from Days 3 to 6 (Figure 2).

ASD Repair

For ASD repair, the CAMEO Acuity Curve extends over a 3‐day median hospital LOS (Figure 2), peaking on Day 1 of CICU admission with a mean score of 116. Similar to TOF and VSD cases, this reflects the immediate postoperative period, with frequent assessments, maintenance of hemodynamic stability through fluid and vasoactive titration, extubation or postextubation. Following this 24‐hour period, acuity decreased until the end of the curve (Figure 2). Stratified acuity curves could not be constructed due to lack of RLS 3 cases.

CAMEO Complexity Classification

Using the ICU and Inpatient CAMEO Complexity Classification System, a guide for nurse staffing assignments and the required level of surveillance, the proportion of total hospital days was highest for Stage I cases (84.9%) and lowest for ASD cases (47.1%). The proportion of CICU and ACCU days followed similar with Stage I cases (78%) having the highest and ASD cases having the lowest (40.5%) (Figure 1).

DISCUSSION

This study expands the novel application of CAMEO data to create Acuity Curves for congenital heart surgical patients. ¹⁶ It demonstrates the feasibility and utility of constructing CAMEO Acuity Curves for 5 procedures: Stage I palliation, ASO repair, TOF repair, VSD repair, and ASD repair, with RLS class stratification identifying higher acuity trends based on adequacy of surgical repair. We also introduce an extended acuity timeline that includes both CICU and ACCU hospital days.

For Stage I, ASO, and TOF cases, CICU days followed similar patterns to the originally constructed CAMEO Acuity Curves. ¹⁶ The Stage I cases experienced their lowest acuity at CICU admission and while awaiting surgery, increasing steadily to Day 3 (surgery), peaking on Day 7, then decreasing with several spikes throughout the 44‐day timeline. Previously, we demonstrated patient acuity rises during and falls after the shift of clinical milestones, such as surgery, bedside chest closure, and extubation. ¹⁶ This reflects acuity's dynamic nature, crucial for the vigilance of interprofessional teams when conducting complex clinical activities.

As in the original CAMEO Acuity Curve for ASO cases, acuity was high at CICU admission and once stabilized, decreased until surgical repair, with spikes during key interventions, such as extubation, followed by a steady decline. TOF, VSD, and ASD cases were often admitted to the CICU postoperatively, demonstrating an increased acuity on Day 1 reflecting the intensive monitoring and management required in the early recovery period, and then a steady decrease.

Stratifying by RLS Class consistently demonstrated higher CAMEO Acuity Curves for RLS Class 3 cases than RLS Class 1 and 2 cases. This mirrors earlier findings that RLS Class 3 cases begin to experience higher acuity with chest closure or extubation. ¹⁶ This increased acuity persisted throughout the hospitalization. Given our retrospective approach, we used RLS assigned at discharge in both analyses to demonstrate that the procedure‐based CAMEO Acuity Curves were able to identify high‐risk patients. ¹⁶ These are patients with a higher‐than‐expected acuity, and higher‐than‐expected acuity curves likely indicate the presence of hemodynamically significant residual lesions. ¹⁶ RLS Class 3 has been associated with increased postoperative complications, neurodevelopmental delay, mortality, LOS, and resource use. ¹⁴ , ²⁵ This underscores the recommendation of a postoperative echocardiogram, ideally on Day 2 or 3 post surgery after expected postoperative hemodynamic instability has resolved, to assess level of residual lesions, ¹⁶ as RLS based on intraoperative echocardiogram may change as hemodynamics stabilize, particularly for valvar lesions. ²⁶ These data can inform timely clinical decisions on imaging or interventions, potentially reducing resource use and LOS.

An extended acuity timeline of hospitalization beyond CICU stay has demonstrated several important findings. First, Stage I cases exhibited the highest mean CAMEO score across the 44‐day hospital stay, indicating a sustained level of acuity necessitating an increased interprofessional surveillance and skilled bedside presence. The proportion of days at higher acuity for Stage I cases was >20% greater in both units compared with the other procedures. Traditional interprofessional staffing models often focus on unit size or patient volume. ³ , ²⁷ , ²⁸ , ²⁹ Day versus night shifts and weekends can also influence staffing patterns. ³⁰ , ³¹ However, not all patients have the same level of complexity and acuity and as we have demonstrated in both the CICU and in the ACCU acuity can be sustained and dynamic in nature. These data add to the considerations necessary to manage effective and efficient inpatient capacity and throughput. ³⁰ , ³² , ³³ Procedure‐based CAMEO Acuity Curves can guide staffing, predictions, assignments, and the necessary team expertise.

In the ACCU, acuity remains elevated beyond the immediate postoperative period, illustrated by upward slopes or spikes in the procedure‐based curves. CAMEO captures multiple attributes of acuity, recognizing that recovery involves more than clinical care. Coordination of care, consultation, education, and family support increase indirect care complexity and cognitive workload. ³⁴ In the cohorts with TOF and VSD, genetic conditions and comorbidities likely contributed to increased acuity at the end of the curve. Staff aware of expected ACCU acuity can guide the discharge roadmap. Any curve deviations support timely care decisions before discharge, including additional imaging and interventions to avoid unplanned readmissions. Current work is underway to examine the relationship between the CAMEO patient acuity, hospital readmission and resource use.

Limitations include small sample size per procedure and RLS class, potentially missing variation of acuity. Other confounding variables such as surgeon experience or timing of complications may also influence acuity scores. As expected, the cohort with ASD lacked RLS Class 3 cases for stratification. Although this study was completed at a single site, the validation of the ICU CAMEO III was competed through participation and use within 15 participating ICUs. Respective acuity curves may vary by ICU, but the methodology can replicate a unit‐specific acuity curve to support communication across the interprofessional team. Multisite collaboration would increase numbers and support benchmarking opportunities. Estimating missing CAMEO scores may have produced less accurate or conservative scores relative to a contemporaneous bedside nursing assessment. An RLS classification on postoperative Day 2 or 3 instead of discharge would best serve as an additional marker of acuity demonstrated by the CAMEO Acuity Curves.

In summary, the CAMEO Acuity Curve helps identify when increased surveillance and possibly intervention may be necessary, ensuring that both immediate and long‐term care needs are communicated across the clinical team and integrated into patient care. The CAMEO Acuity Curves not only support evidence‐based staffing but also offer a framework for measuring patient acuity and the diverse needs of pediatric patients during hospitalization. As we continue to refine and validate this methodology, application across other medical and surgical conditions will be explored as the CAMEO acuity tool is used for all patient hospitalizations. ²¹

CONCLUSIONS

The development of procedure‐specific CAMEO Acuity Curves illustrates expected periods of high acuity throughout the hospitalization experience and variation in acuity by surgical procedure and patient surgical status. This approach may be used to inform timely clinical decisions, assessment of interprofessional staffing requirements, facilitate throughput, and project resource needs for providing optimal care for children undergoing cardiac surgery.

Sources of Funding

This work was supported by the Inquiry Investment Drives Evidence into Action grant from the Nurse Executive Committee for Research and Inquiry at Boston Children's Hospital.

Disclosures

Dr Thiagarajan discloses speaker fees from the Society of Critical Care Medicine and the Extracorporeal Life Support Organization. Dr.Thiagarajan has also received grant funding through the United States Department of Defense. PRMRP Clinical Trial Award # W81XWH2210301: coinvestigator: TITRE: Trial of Indication‐based Transfusion of Red blood cells in ECMO; cochair, Clinical Coordinating Center. The remaining authors have no disclosures to report.