Sunil Saharan, MD, Arthur T. Legg, MD, Laurie B. Armsby, MD, M. Mujeeb Zubair, MD, Richard D. Reed, MD, and Stephen M. Langley, MD, FRCS (CTh) Division of Pediatric Cardiology and Division of Pediatric Cardiac Surgery, Department of Pediatrics and Surgery, Doernbecher Children’s Hospital, Portland, Oregon
Background. Readmission after operations for congenital heart conditions has significant implications for patient care. Readmission rates vary between 8.7% and 15%. The aim of this study was to determine the incidence, causes, and risk factors associated with readmission. Methods. 811 consecutive patients undergoing operations for congenital heart conditions were analyzed. Readmission was defined as admission to any hospital within 30 days of discharge for any cause. Demographic, preoperative, operative, and postoperative variables were evaluated. Univariate comparisons were made between the nonreadmission and readmission groups, and multivariate logistic regression analysis was made to determine independent risk factors for readmission. Results. There were a total of 92 readmissions in 79 patients (9.7%). The reasons included cardiac (36, 39%), pulmonary (20, 22%), gastrointestinal (13, 14%), infectious (20, 22%), and other adverse events (2, 2%). Patients with either single-ventricle palliation or nasogastric feeding accounted for 40 (50%) readmissions. On univariate analysis, there were significant differences between
readmitted and nonreadmitted patients in relation to patient age, chromosomal abnormality, mortality risk score, duration of mechanical ventilation, postoperative length of stay, single-ventricle physiology, and nasogastric feeding at discharge (p < 0.05). On multivariate analysis, significant risk factors for readmission were single-ventricle physiology (odds ratio [OR] 2.39; 95% confidence interval [CI] 1.28 to 4.47; p [ 0.005), preoperative arrhythmia (OR 2.59; 95% CI 1.02 to 6.59; p [ 0.04), longer postoperative length of stay (OR 2.2; 95% CI 1.22 to 3.99; p [ 0.008), and nasogastric tube feeding at discharge (OR 2.2; 95% CI 1.15 to 4.19; p [ 0.01). Conclusions. The incidence of readmission after operations for congenital cardiac conditions remains high. Efforts focusing on patients with single-ventricle palliation and those with preoperative arrhythmia, prolonged postoperative length of stay and nasogastric tube feeding at discharge may be particularly beneficial.
O
Patients and Methods
ver the past 2 decades we have witnessed a significant reduction in mortality, particularly in high-risk procedures. More recently, focus has shifted toward reducing morbidity, hospital length of stay, and incidence of readmission after cardiac operations. In many respects, these factors are the surrogates for quality of care in the modern era. Efforts focused on reducing the incidence of readmission may be particularly beneficial. A first step in that direction is identification of the cause of, and associated risk factors for, readmission. Once this knowledge is gained, modifiable risk factors could be addressed to reduce the incidence of readmission and associated costs of health care. With these things in mind, we planned our study specifically looking for the incidence, causes of, and associated risk factors for readmission.
Accepted for publication May 22, 2014. Presented at the Poster Session of the Fiftieth Annual Meeting of The Society of Thoracic Surgeons, Orlando, FL, Jan 25–29, 2014. Address correspondence to Dr Saharan, Pediatric Cardiology, Doernbecher Children’s Hospital, Oregon Health & Science University, CDRC-P, 707 SW Gaines Rd, Portland, OR 97239; e-mail: [email protected].
Ó 2014 by The Society of Thoracic Surgeons Published by Elsevier
(Ann Thorac Surg 2014;98:1667–73) Ó 2014 by The Society of Thoracic Surgeons
The Institutional Review Board at Oregon Health & Science University approved the study. After approval, we performed a retrospective cohort study of 840 consecutive patients who underwent at least one cardiac operation at Doernbecher Children’s Hospital between 2008 and 2012. Twenty-nine patients were excluded because of early postoperative mortality, leaving 811 patients in the cohort. Patients with more than one operative procedure during a single admission were counted as 1 patient. Readmission was defined as an admission to any hospital for any cause within 30 days of discharge. We analyzed our surgical database, hospital admission and discharge data, the operating room log, anesthesia records, cardiac catheterization laboratory records, and pediatric intensive care unit records to ensure the completeness of data.
Study Variables The primary outcome was incidence of readmission. Secondary outcomes were cause of readmission and associated risk factors. The demographic variables were studied. Potential risk factors included preoperative, operative, and postoperative variables. Preoperative risk factors included 0003-4975/$36.00 http://dx.doi.org/10.1016/j.athoracsur.2014.05.043
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prematurity, chromosome abnormality, syndrome, asplenia or polysplenia, arrhythmia, infection, mechanical ventilation, tracheostomy, and various other factors involving hematologic, gastrointestinal, neurologic, endocrine, and renal systems. The operative factors were surgeon and operation type. The operations were categorized 1 to 5 mortality risk on the basis of the Society of Thoracic Surgeons and European Association for Cardiothoracic Surgery (STS-EACTS) score classification (STAT score) [1]. Postoperative risk factors were duration of mechanical ventilation, intensive care unit and hospital length of stay, single-ventricle physiology, palliated physiology, and nasogastric tube feeding at discharge. The data regarding readmitted patients included cause of readmission, time to readmission, admitting unit, procedures, and hospital length of stay.
Statistical Analysis All analyses were performed with SAS version 9.3 (SAS Institute, Cary, NC). Univariate logistic regression was undertaken to evaluate the risk factors associated with readmission. The final multivariate logistic regression model was constructed with stepwise logistic regression.
Results Population Summary The median age of 811 patients included in the study was 491 days (range, 1 to 26,192 days), and the median weight was 9 kg (range, 0.6 to 163 kg). The majority of patients were white (76%), and there was a slight male preponderance (54%). A significant number of patients were either neonates (134, 17%) or weighed less than 5 kg at the time of operations (216, 27%). The most common preoperative factors were chromosome abnormality (136, 17%), prematurity (108, 13%), any syndrome (65, 8%), and preoperative arrhythmia (45, 6%). Surgeon A performed the majority of operations (656, 81%). According to the STSEACTS mortality risk categories for operations, a total of 335 operations (41%) were in category 1, 260 (32%) in category 2, 90 (11%) in category 3, 104 (13%) in category 4, and 22 (3%) in category 5 (Table 1). Ninety-three (11%) patients had single-ventricle physiology, and another 19 (2%) had palliated physiology at the time of discharge. Routine chest roentgenography and echocardiography were performed on the day of discharge for all the patients. All patients were discharged home to receive oral furosemide for 2 to 3 weeks. One hundred (12%) patients were discharged home with nasogastric tube feeding. The median duration of mechanical ventilation was 0.9 day (range, 0.03 to 87 days), and the median hospital length of stay was 6 days (range, 1 to 131 days) (Table 1).
Readmission Summary There were a total of 92 readmissions in 79 patients (9.7%). Ten patients were readmitted twice, and 3 patients were readmitted three times within 30 days from the initial discharge. Only 2 patients were readmitted to a peripheral hospital. The median time to readmission
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from the day of discharge was 7 days (range, 1 to 29 days). The reasons for readmission were cardiac (36, 39%), pulmonary (20, 22%), infectious (20, 22%), gastrointestinal (13, 14%), renal (1, 1%), and other (2, 2%). Overall, the patients readmitted because of cardiovascular conditions had a high intervention rate, in as much as 17 of 36 patients (47%) required either effusion drainage or a catheter procedure. The admitting unit was a hospital ward for 57 patients (62%) and an intensive care unit for 35 patients (38%). The median length of hospital stay during readmission was 3.9 days (range, 0.5 to 44.5 days) (Table 2). The most common causes of readmission included pleural effusion (16), arrhythmia (9), bronchiolitis (7), failure to thrive (7), residual hemodynamic lesion (5), and superficial wound infection (12). Two patients were readmitted because of respiratory syncytial virus infection (Table 3). In some patients it is difficult to categorize between primary pulmonary pathologic conditions and respiratory difficulty secondary to cardiovascular problems. We have used our best judgment in relation to this. Focal consolidation on chest roentgenogram, isolation of virus from respiratory secretions, or history of concurrent sick family member with similar symptoms was more suggestive of a primary pulmonary pathologic condition. Of 7 patients readmitted with feeding problems, only 1 patient had residual palliated physiology. The other 6 patients had two-ventricle physiology after surgical repair. Feeding problems in these patients were less likely to be related to heart failure and more likely to be related to other comorbid conditions such as chromosome anomaly or an underlying syndrome (Table 3). The original operation, postoperative hospital length of stay, and relationship of original operation to readmission are summarized in Table 4. A total of 23 patients underwent 26 procedures during readmission. Drainage of pleural effusion was required in 10 patients and pericardial effusion in another 1 patient. The surgical interventions during readmission included sternal wound exploration in 2 patients and repair of right ventricle free wall injury secondary to pericardiocentesis attempt in 1 patient. A permanent pacemaker was implanted in 2 patients in the electrophysiology laboratory. The noncardiac surgical interventions included gastric tube insertion in 2 patients, jejunostomy tube insertion in 1, repair of omphalocele in 1, and plication of diaphragm in another patient. One patient underwent surgical pacemaker lead replacement secondary to insulation break, and another 4 patients underwent a cardiac catheterization procedure for residual hemodynamic lesions during readmission. Cardiac catheterization interventions included balloon dilation of recoarctation of aorta in 1 patient, stent dilation of Glenn anastomosis stenosis in 1, and stent dilation of pulmonary artery stenosis in 2 patients. The median length of stay for these patients requiring reinterventions was 5 days (range 1 to 9 days). This subgroup accounted for a total of 24 inpatient days during readmission.
Univariate Analysis On univariate analysis, the risk factors associated with readmission included younger age, chromosome
SAHARAN ET AL READMISSION AFTER PEDIATRIC CARDIAC OPERATION
Table 1. Summary of Demographic, Preoperative, Operative and Postoperative Risk Factors Variable Demographic factors Age at operation 1 year Weight at operation (kg) 10 Gender Male Female Ethnicity White Hispanic Other Preoperative factors Chromosomal anomaly Down syndrome DiGeorge syndrome Other syndromes Asplenia/polysplenia Prematurity Arrhythmia Other cardiovascular factors Mechanical ventilation Tracheostomy Neurologic factors Infectious disease factors Gastrointestinal factors Endocrine factors Renal factors Hematologic factors Operative factors Surgeon A B C STAT score 1 2 3 4 5 Postoperative factors Single ventricle physiology Palliated physiology NG tube feeding at discharge Mechanical ventilation (days) 5 153 19 Hospital length of stay (days) 1–5 249 31 6–10 319 39 >10 243 30
NG ¼ nasogastric; STAT score ¼ The Society of Thoracic Surgeons and European Association for Cardiothoracic Surgery (STS-EACTS) mortality risk.
abnormality, gastrointestinal factors, STAT score, single-ventricle palliation, longer duration of mechanical ventilation, longer postoperative length of stay, longer intensive care unit length of stay, and nasogastric tube feeding at discharge (p < 0.05) (Table 5).
435 54 376 46 615 76 136 17 60 7
Multivariate Analysis 136 17 77 9 32 4 65 8 13 2 108 13 45 6 20 2 35 4 3 0 33 4 12 1 36 4 10 1 16 2 11 1
The independent predictors for readmission on multivariate analysis were preoperative arrhythmia, singleventricle physiology, longer postoperative length of stay, and nasogastric tube feeding at discharge (Table 6).
Comment The outcomes after operations for congenital cardiac conditions have improved significantly in terms of mortality over the past couple of decades. The most recent mortality rate for all surgical procedures is 3.5% [2]. Early postoperative mortality for individual lesions has also improved [3–6]. In recent years, focus has started to center on improvement in quality of care, which encompasses morbidity and readmissions [7–9]. Table 2. Summary of Readmission Statistics
656 81 68 8 87 11 335 260 90 104 22
Variable
41 32 11 13 3
93 11 19 2 100 12 0.9
0.03–87
416 51 184 23 (Continued)
n
Time to first readmission (n ¼ 79) Cause (n ¼ 92) Cardiovascular 36 Respiratory 20 Infectious 20 Gastrointestinal 13 Renal 1 Other 2 Admitting unit (n ¼ 92) Ward 57 ICU 35 Hospital length of stay (n ¼ 92) ICU ¼ intensive care unit.
%
Median (Days) 7
Range (Days) 1–29
39 22 22 14 1 2
62 38 3.99
0.59–44.5
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Table 3. Cause of Readmission Readmission CONGENITAL HEART
Variable
n
Cardiovascular Pleural effusion Pericardial effusion Arrhythmia Procedures for residual lesion Heart failure Respiratory Pneumonia Bronchiolitis Respiratory distress or failure Suture dehiscence of plicated diaphragm Diaphragmatic hernia Vocal cord paralysis Cyanosis, unexplained Gastrointestinal FTT GERD Diarrhea Omphalocele repair Infectious Superficial wound infection Deep wound infection Sepsis Superficial Candida infection Tracheitis Viral URI UTI Renal Acute renal failure Other Chest pain Total
36
FTT ¼ failure to thrive; tract infection.
(n)
Repeat Readmission n
16 2 9 5 4
Median LOS in Days (Range)
2
6.6 5.2 1.2 5 9
1 2
(1–29) (2.7–7.7) (1–13) (1–9.7) (1.5–20)
20 4 7 4 1 1 1 2
1 2
2.2 9.9 1.15 11.8 32.7 1 1.15
(1.5–8) (1–44) (0.8–9) (11.8) (32.7) (1) (1–1.3)
4.3 1.45 8.5 6.7
(1.2–13.8) (1.2–2) (8.5) (6.7)
2.5 7.8 1 1 9.3 2.7 1.6
(0.5–7.6) (5.7–21) (1) (1) (9.3) (2.7) (1.6)
13 7 4 1 1
2 1
20 12 3 1 1 1 1 1
1
1 1
1
19.6 (19.6)
2
GERD ¼ gastroesophageal reflux disease;
Successful attempts to reduce hospital length of stay and cost after operations for congenital cardiac conditions have been achieved by use of a critical pathway or a fast-track method [10–12]. Readmission after operations for congenital cardiac conditions, however, continues to remain high, ranging between 8.7% and 15% [13, 14]. Our readmission rate of 9.7% is comparable to that in prior studies. The key to reducing readmission is identification and correction of modifiable risk factors. The reported risk factors associated with readmission in the past have been Hispanic ethnicity, preoperative failure to thrive, prolonged hospital length of stay, residual hemodynamic lesion, and postoperative feeding problems [13, 15]. In addition to these factors shown elsewhere, we also found that preoperative arrhythmia and nasogastric tube feeding also contribute significantly to readmission. In our program, postoperative care, including discharge, is based on a variety of protocols. In neonates,
2 92 LOS ¼ length of stay;
1.3 (0.7-2)
URI ¼ upper respiratory infection;
UTI ¼ urinary
for example, a prerequisite for discharge is a minimum weight gain of 20 grams per day while the infant is receiving enteral feeding. After complex neonatal cardiac operations and atrioventricular septal defect repair, patients tend to have a more difficult transition to oral feeding and often require nasogastric tube feeding to reduce the length of stay. Patients who receive nasogastric tube feeding, however, tend to have a higher incidence of vomiting, gastroesophageal reflux, aspiration, inadequate weight gain, and tube displacement, necessitating readmission frequently. We suggest that close follow-up, akin to interstage home monitoring, may reduce readmission by early identification of the problem and intervention. Patients with single-ventricle physiology and preoperative arrhythmia have a higher incidence of rhythm problems during the postoperative period, leading to prolonged hospital length of stay and readmission. We
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Table 4. Summary Statistics of Surgical Procedures and Relation to Readmission
Operation ALCAPA repair LVOT procedure Arterial switch operation ASD enlargement ASD repair AVSD repair Glenn procedure Cardiac tumor resection Coarctation repair Coarctation þ VSD RVOT procedure Ebstein’s repair Fontan procedure ICD implantation Interrupted aortic arch repair Norwood procedure PA banding PA plasty Pacemaker implantation PDA ligation Aortopulmonary shunt TAPVR repair TOF or PA/VSD Truncus arteriosus repair Aortic valve repair or replacement Pulmonic valve repair or replacement Tricuspid valve repair or replacement Mitral valve repair or replacement Vascular ring repair VSD closure Other Total
Readmitted Patients
n
Median LOS (Days)
Range (Days)
n
3 27 25 6 61 49 34 2 66 5 37 5 38 4 4 21 6 4 48 37 19 16 54 3 22 58 15 18 15 86 23 811
5 5 14 5.5 4 7 8 11.5 6 11 6 11 12.5 4 14.5 28 6.5 5 1 43 10 11.5 7 29 6.5 5 7 6 3 5 7 6
5–6 3–26 7–51 3–8 2–26 264 5–77 8–15 3–120 8–62 3–64 4–23 6–131 2–10 7–53 10–129 3–39 3–9 0–40 2–111 3–79 5–84 3–66 9–70 3–13 3–51 4–25 3–10 2–16 2–26 3–49 0–131
0 2 0 0 2 6 11 0 7 0 2 0 8 0 1 5 1 0 2 2 4 0 5 0 2 5 3 4 1 5 1 79
% of Each Procedure
% of All Readmissions
0 7.4 0 0 3.3 12.2 32.3 0 10.6 0 5.4 0 21 0 25 23.8 16.7 0 4.2 5.4 21 0 9.2 0 9 8.6 20 22.2 6.6 5.8 4.3
0 2.6 0 0 2.6 7.5 14 0 8.8 0 2.6 0 10 0 1.3 6.3 1.3 0 2.6 2.6 5 0 6.3 0 2.6 6.3 3.7 5 1.3 6.3 1.3 100
ALCAPA ¼ anomalous origin of left coronary artery from pulmonary artery; ASD ¼ atrial septal defect; AVSD ¼ atrioventricular septal defect; ICD ¼ implantable cardioverter defibrillator; LOS ¼ length of stay; LVOT ¼ left ventricular outflow tract; PA ¼ pulmonary artery; PA/VSD ¼ pulmonary atresia/ventricular septal defect; PDA ¼ patent ductus arteriosus; RVOT ¼ right ventricular outflow tract; TAPVR ¼ total anomalous pulmonary venous return; TOF ¼ tetralogy of Fallot; VSD ¼ ventricular septal defect.
suggest that aggressive management of rhythm problems before discharge along with early follow-up within a week may be particularly beneficial. Postoperative hospital length of stay is a direct marker of morbidity. Patients with prolonged hospital length of stay typically have other associated comorbid conditions. As an example, pleural effusion is associated with both prolonged hospital stay and readmission. Efforts focusing on diuresis in this particular subgroup may be helpful in reducing readmission. We suggest that early follow-up of these patients, combined with early interventions like changing the diuretic regimen, may be of particular benefit. Although Hispanic ethnicity has previously been identified as a risk factor for readmission because of a language barrier, this was not significant in our patient population even though 17% of our patients were Hispanic.
The most common causes of readmission reported in a prior large single-center study were pleural or pericardial effusion (26%) and gastrointestinal (24%), infectious (19%), and cardiac (15%) conditions [13]. Other prior studies have also reported similar causes [3, 11]. By contrast, the most common cause of readmission in our patients was cardiovascular. Pleural effusion was more frequently associated with Glenn and Fontan procedures and about two thirds of these patients required drainage during readmission. More aggressive diuresis, as suggested earlier, could potentially reduce readmissions in this subgroup. Early follow-up after discharge with a chest roentgenogram and adjustment of diuretic dose could potentially reduce some of the readmissions, given that the median time to readmission was 7 days in our patient population. In light of this, we are instituting
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All Patients
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Table 5. Continued
Table 5. Summary of Univariate Analysis of Variables Between Nonreadmission and Readmission Groups
CONGENITAL HEART
Nonreadmission Readmission (n ¼ 732) (n ¼ 79) Variable Demographic factors Age at operation 1 year Weight at operation (kg) 10 Gender Male Female Ethnicity White Hispanic Other Preoperative factors Chromosomal abnormality Down DiGeorge syndrome Other syndromes Asplenia/polysplenia Arrhythmia Other cardiovascular factors Mechanical ventilation Tracheostomy Neurologic factors Prematurity Infectious disease factors Gastrointestinal factors Endocrine factors Renal Hematologic factors Other Operative factors Assigned surgeon A B C STAT score 1 2 3 4 5
n
%
n
%
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Nonreadmission Readmission (n ¼ 732) (n ¼ 79) p Value
118 221 393
16 30 54
16 32 31
20 41 39
0.049
193 174 364
26 24 50
23 27 29
29 34 37
0.059
392 340
54 46
43 36
54 36
0.881
558 119 55
76 16 8
57 17 5
72 22 6
0.498
115
16
21
27
0.015
67 29 55 12 38 17
9 4 8 2 5 2
10 3 10 1 7 3
13 4 13 1 9 4
0.315 0.944 0.114 0.802 0.181 0.426
29
4
6
8
0.138
1 27 95 9
0 4 13 1
2 6 13 3
3 8 16 4
0.052 0.102 0.388 0.205
27
4
9
11
0.002
9 15 9 1
1 2 1 0
1 1 1 1
1 1 1 1
1 0.637 1 0.370
585 66 81
80 9 11
71 2 6
89 3 8
0.096
318 225 82 90 17
43 31 11 12 2
17 35 8 14 5
22 44 10 18 6
0.002
Variable Postoperative factors Single ventricle Palliated physiology Mechanical ventilation (days) 5 NG tube feeding at discharge ICU LOS (days) 0 1–2 3–5 >5 Postoperative LOS (days) 1–5 6–10 >10
n
%
n
%
p Value
69 15
9 2
24 4
30 5
Background. Readmission after operations for congenital heart conditions has significant implications for patient care. Readmission rates vary between 8.7% and 15%. The aim of this study was to determine the incidence, causes, and risk factors associated with readmission. Methods. 811 consecutive patients undergoing operations for congenital heart conditions were analyzed. Readmission was defined as admission to any hospital within 30 days of discharge for any cause. Demographic, preoperative, operative, and postoperative variables were evaluated. Univariate comparisons were made between the nonreadmission and readmission groups, and multivariate logistic regression analysis was made to determine independent risk factors for readmission. Results. There were a total of 92 readmissions in 79 patients (9.7%). The reasons included cardiac (36, 39%), pulmonary (20, 22%), gastrointestinal (13, 14%), infectious (20, 22%), and other adverse events (2, 2%). Patients with either single-ventricle palliation or nasogastric feeding accounted for 40 (50%) readmissions. On univariate analysis, there were significant differences between
readmitted and nonreadmitted patients in relation to patient age, chromosomal abnormality, mortality risk score, duration of mechanical ventilation, postoperative length of stay, single-ventricle physiology, and nasogastric feeding at discharge (p < 0.05). On multivariate analysis, significant risk factors for readmission were single-ventricle physiology (odds ratio [OR] 2.39; 95% confidence interval [CI] 1.28 to 4.47; p [ 0.005), preoperative arrhythmia (OR 2.59; 95% CI 1.02 to 6.59; p [ 0.04), longer postoperative length of stay (OR 2.2; 95% CI 1.22 to 3.99; p [ 0.008), and nasogastric tube feeding at discharge (OR 2.2; 95% CI 1.15 to 4.19; p [ 0.01). Conclusions. The incidence of readmission after operations for congenital cardiac conditions remains high. Efforts focusing on patients with single-ventricle palliation and those with preoperative arrhythmia, prolonged postoperative length of stay and nasogastric tube feeding at discharge may be particularly beneficial.
O
Patients and Methods
ver the past 2 decades we have witnessed a significant reduction in mortality, particularly in high-risk procedures. More recently, focus has shifted toward reducing morbidity, hospital length of stay, and incidence of readmission after cardiac operations. In many respects, these factors are the surrogates for quality of care in the modern era. Efforts focused on reducing the incidence of readmission may be particularly beneficial. A first step in that direction is identification of the cause of, and associated risk factors for, readmission. Once this knowledge is gained, modifiable risk factors could be addressed to reduce the incidence of readmission and associated costs of health care. With these things in mind, we planned our study specifically looking for the incidence, causes of, and associated risk factors for readmission.
Accepted for publication May 22, 2014. Presented at the Poster Session of the Fiftieth Annual Meeting of The Society of Thoracic Surgeons, Orlando, FL, Jan 25–29, 2014. Address correspondence to Dr Saharan, Pediatric Cardiology, Doernbecher Children’s Hospital, Oregon Health & Science University, CDRC-P, 707 SW Gaines Rd, Portland, OR 97239; e-mail: [email protected].
Ó 2014 by The Society of Thoracic Surgeons Published by Elsevier
(Ann Thorac Surg 2014;98:1667–73) Ó 2014 by The Society of Thoracic Surgeons
The Institutional Review Board at Oregon Health & Science University approved the study. After approval, we performed a retrospective cohort study of 840 consecutive patients who underwent at least one cardiac operation at Doernbecher Children’s Hospital between 2008 and 2012. Twenty-nine patients were excluded because of early postoperative mortality, leaving 811 patients in the cohort. Patients with more than one operative procedure during a single admission were counted as 1 patient. Readmission was defined as an admission to any hospital for any cause within 30 days of discharge. We analyzed our surgical database, hospital admission and discharge data, the operating room log, anesthesia records, cardiac catheterization laboratory records, and pediatric intensive care unit records to ensure the completeness of data.
Study Variables The primary outcome was incidence of readmission. Secondary outcomes were cause of readmission and associated risk factors. The demographic variables were studied. Potential risk factors included preoperative, operative, and postoperative variables. Preoperative risk factors included 0003-4975/$36.00 http://dx.doi.org/10.1016/j.athoracsur.2014.05.043
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Causes of Readmission After Operation for Congenital Heart Disease
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prematurity, chromosome abnormality, syndrome, asplenia or polysplenia, arrhythmia, infection, mechanical ventilation, tracheostomy, and various other factors involving hematologic, gastrointestinal, neurologic, endocrine, and renal systems. The operative factors were surgeon and operation type. The operations were categorized 1 to 5 mortality risk on the basis of the Society of Thoracic Surgeons and European Association for Cardiothoracic Surgery (STS-EACTS) score classification (STAT score) [1]. Postoperative risk factors were duration of mechanical ventilation, intensive care unit and hospital length of stay, single-ventricle physiology, palliated physiology, and nasogastric tube feeding at discharge. The data regarding readmitted patients included cause of readmission, time to readmission, admitting unit, procedures, and hospital length of stay.
Statistical Analysis All analyses were performed with SAS version 9.3 (SAS Institute, Cary, NC). Univariate logistic regression was undertaken to evaluate the risk factors associated with readmission. The final multivariate logistic regression model was constructed with stepwise logistic regression.
Results Population Summary The median age of 811 patients included in the study was 491 days (range, 1 to 26,192 days), and the median weight was 9 kg (range, 0.6 to 163 kg). The majority of patients were white (76%), and there was a slight male preponderance (54%). A significant number of patients were either neonates (134, 17%) or weighed less than 5 kg at the time of operations (216, 27%). The most common preoperative factors were chromosome abnormality (136, 17%), prematurity (108, 13%), any syndrome (65, 8%), and preoperative arrhythmia (45, 6%). Surgeon A performed the majority of operations (656, 81%). According to the STSEACTS mortality risk categories for operations, a total of 335 operations (41%) were in category 1, 260 (32%) in category 2, 90 (11%) in category 3, 104 (13%) in category 4, and 22 (3%) in category 5 (Table 1). Ninety-three (11%) patients had single-ventricle physiology, and another 19 (2%) had palliated physiology at the time of discharge. Routine chest roentgenography and echocardiography were performed on the day of discharge for all the patients. All patients were discharged home to receive oral furosemide for 2 to 3 weeks. One hundred (12%) patients were discharged home with nasogastric tube feeding. The median duration of mechanical ventilation was 0.9 day (range, 0.03 to 87 days), and the median hospital length of stay was 6 days (range, 1 to 131 days) (Table 1).
Readmission Summary There were a total of 92 readmissions in 79 patients (9.7%). Ten patients were readmitted twice, and 3 patients were readmitted three times within 30 days from the initial discharge. Only 2 patients were readmitted to a peripheral hospital. The median time to readmission
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from the day of discharge was 7 days (range, 1 to 29 days). The reasons for readmission were cardiac (36, 39%), pulmonary (20, 22%), infectious (20, 22%), gastrointestinal (13, 14%), renal (1, 1%), and other (2, 2%). Overall, the patients readmitted because of cardiovascular conditions had a high intervention rate, in as much as 17 of 36 patients (47%) required either effusion drainage or a catheter procedure. The admitting unit was a hospital ward for 57 patients (62%) and an intensive care unit for 35 patients (38%). The median length of hospital stay during readmission was 3.9 days (range, 0.5 to 44.5 days) (Table 2). The most common causes of readmission included pleural effusion (16), arrhythmia (9), bronchiolitis (7), failure to thrive (7), residual hemodynamic lesion (5), and superficial wound infection (12). Two patients were readmitted because of respiratory syncytial virus infection (Table 3). In some patients it is difficult to categorize between primary pulmonary pathologic conditions and respiratory difficulty secondary to cardiovascular problems. We have used our best judgment in relation to this. Focal consolidation on chest roentgenogram, isolation of virus from respiratory secretions, or history of concurrent sick family member with similar symptoms was more suggestive of a primary pulmonary pathologic condition. Of 7 patients readmitted with feeding problems, only 1 patient had residual palliated physiology. The other 6 patients had two-ventricle physiology after surgical repair. Feeding problems in these patients were less likely to be related to heart failure and more likely to be related to other comorbid conditions such as chromosome anomaly or an underlying syndrome (Table 3). The original operation, postoperative hospital length of stay, and relationship of original operation to readmission are summarized in Table 4. A total of 23 patients underwent 26 procedures during readmission. Drainage of pleural effusion was required in 10 patients and pericardial effusion in another 1 patient. The surgical interventions during readmission included sternal wound exploration in 2 patients and repair of right ventricle free wall injury secondary to pericardiocentesis attempt in 1 patient. A permanent pacemaker was implanted in 2 patients in the electrophysiology laboratory. The noncardiac surgical interventions included gastric tube insertion in 2 patients, jejunostomy tube insertion in 1, repair of omphalocele in 1, and plication of diaphragm in another patient. One patient underwent surgical pacemaker lead replacement secondary to insulation break, and another 4 patients underwent a cardiac catheterization procedure for residual hemodynamic lesions during readmission. Cardiac catheterization interventions included balloon dilation of recoarctation of aorta in 1 patient, stent dilation of Glenn anastomosis stenosis in 1, and stent dilation of pulmonary artery stenosis in 2 patients. The median length of stay for these patients requiring reinterventions was 5 days (range 1 to 9 days). This subgroup accounted for a total of 24 inpatient days during readmission.
Univariate Analysis On univariate analysis, the risk factors associated with readmission included younger age, chromosome
SAHARAN ET AL READMISSION AFTER PEDIATRIC CARDIAC OPERATION
Table 1. Summary of Demographic, Preoperative, Operative and Postoperative Risk Factors Variable Demographic factors Age at operation 1 year Weight at operation (kg) 10 Gender Male Female Ethnicity White Hispanic Other Preoperative factors Chromosomal anomaly Down syndrome DiGeorge syndrome Other syndromes Asplenia/polysplenia Prematurity Arrhythmia Other cardiovascular factors Mechanical ventilation Tracheostomy Neurologic factors Infectious disease factors Gastrointestinal factors Endocrine factors Renal factors Hematologic factors Operative factors Surgeon A B C STAT score 1 2 3 4 5 Postoperative factors Single ventricle physiology Palliated physiology NG tube feeding at discharge Mechanical ventilation (days) 5 153 19 Hospital length of stay (days) 1–5 249 31 6–10 319 39 >10 243 30
NG ¼ nasogastric; STAT score ¼ The Society of Thoracic Surgeons and European Association for Cardiothoracic Surgery (STS-EACTS) mortality risk.
abnormality, gastrointestinal factors, STAT score, single-ventricle palliation, longer duration of mechanical ventilation, longer postoperative length of stay, longer intensive care unit length of stay, and nasogastric tube feeding at discharge (p < 0.05) (Table 5).
435 54 376 46 615 76 136 17 60 7
Multivariate Analysis 136 17 77 9 32 4 65 8 13 2 108 13 45 6 20 2 35 4 3 0 33 4 12 1 36 4 10 1 16 2 11 1
The independent predictors for readmission on multivariate analysis were preoperative arrhythmia, singleventricle physiology, longer postoperative length of stay, and nasogastric tube feeding at discharge (Table 6).
Comment The outcomes after operations for congenital cardiac conditions have improved significantly in terms of mortality over the past couple of decades. The most recent mortality rate for all surgical procedures is 3.5% [2]. Early postoperative mortality for individual lesions has also improved [3–6]. In recent years, focus has started to center on improvement in quality of care, which encompasses morbidity and readmissions [7–9]. Table 2. Summary of Readmission Statistics
656 81 68 8 87 11 335 260 90 104 22
Variable
41 32 11 13 3
93 11 19 2 100 12 0.9
0.03–87
416 51 184 23 (Continued)
n
Time to first readmission (n ¼ 79) Cause (n ¼ 92) Cardiovascular 36 Respiratory 20 Infectious 20 Gastrointestinal 13 Renal 1 Other 2 Admitting unit (n ¼ 92) Ward 57 ICU 35 Hospital length of stay (n ¼ 92) ICU ¼ intensive care unit.
%
Median (Days) 7
Range (Days) 1–29
39 22 22 14 1 2
62 38 3.99
0.59–44.5
CONGENITAL HEART
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Table 3. Cause of Readmission Readmission CONGENITAL HEART
Variable
n
Cardiovascular Pleural effusion Pericardial effusion Arrhythmia Procedures for residual lesion Heart failure Respiratory Pneumonia Bronchiolitis Respiratory distress or failure Suture dehiscence of plicated diaphragm Diaphragmatic hernia Vocal cord paralysis Cyanosis, unexplained Gastrointestinal FTT GERD Diarrhea Omphalocele repair Infectious Superficial wound infection Deep wound infection Sepsis Superficial Candida infection Tracheitis Viral URI UTI Renal Acute renal failure Other Chest pain Total
36
FTT ¼ failure to thrive; tract infection.
(n)
Repeat Readmission n
16 2 9 5 4
Median LOS in Days (Range)
2
6.6 5.2 1.2 5 9
1 2
(1–29) (2.7–7.7) (1–13) (1–9.7) (1.5–20)
20 4 7 4 1 1 1 2
1 2
2.2 9.9 1.15 11.8 32.7 1 1.15
(1.5–8) (1–44) (0.8–9) (11.8) (32.7) (1) (1–1.3)
4.3 1.45 8.5 6.7
(1.2–13.8) (1.2–2) (8.5) (6.7)
2.5 7.8 1 1 9.3 2.7 1.6
(0.5–7.6) (5.7–21) (1) (1) (9.3) (2.7) (1.6)
13 7 4 1 1
2 1
20 12 3 1 1 1 1 1
1
1 1
1
19.6 (19.6)
2
GERD ¼ gastroesophageal reflux disease;
Successful attempts to reduce hospital length of stay and cost after operations for congenital cardiac conditions have been achieved by use of a critical pathway or a fast-track method [10–12]. Readmission after operations for congenital cardiac conditions, however, continues to remain high, ranging between 8.7% and 15% [13, 14]. Our readmission rate of 9.7% is comparable to that in prior studies. The key to reducing readmission is identification and correction of modifiable risk factors. The reported risk factors associated with readmission in the past have been Hispanic ethnicity, preoperative failure to thrive, prolonged hospital length of stay, residual hemodynamic lesion, and postoperative feeding problems [13, 15]. In addition to these factors shown elsewhere, we also found that preoperative arrhythmia and nasogastric tube feeding also contribute significantly to readmission. In our program, postoperative care, including discharge, is based on a variety of protocols. In neonates,
2 92 LOS ¼ length of stay;
1.3 (0.7-2)
URI ¼ upper respiratory infection;
UTI ¼ urinary
for example, a prerequisite for discharge is a minimum weight gain of 20 grams per day while the infant is receiving enteral feeding. After complex neonatal cardiac operations and atrioventricular septal defect repair, patients tend to have a more difficult transition to oral feeding and often require nasogastric tube feeding to reduce the length of stay. Patients who receive nasogastric tube feeding, however, tend to have a higher incidence of vomiting, gastroesophageal reflux, aspiration, inadequate weight gain, and tube displacement, necessitating readmission frequently. We suggest that close follow-up, akin to interstage home monitoring, may reduce readmission by early identification of the problem and intervention. Patients with single-ventricle physiology and preoperative arrhythmia have a higher incidence of rhythm problems during the postoperative period, leading to prolonged hospital length of stay and readmission. We
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Table 4. Summary Statistics of Surgical Procedures and Relation to Readmission
Operation ALCAPA repair LVOT procedure Arterial switch operation ASD enlargement ASD repair AVSD repair Glenn procedure Cardiac tumor resection Coarctation repair Coarctation þ VSD RVOT procedure Ebstein’s repair Fontan procedure ICD implantation Interrupted aortic arch repair Norwood procedure PA banding PA plasty Pacemaker implantation PDA ligation Aortopulmonary shunt TAPVR repair TOF or PA/VSD Truncus arteriosus repair Aortic valve repair or replacement Pulmonic valve repair or replacement Tricuspid valve repair or replacement Mitral valve repair or replacement Vascular ring repair VSD closure Other Total
Readmitted Patients
n
Median LOS (Days)
Range (Days)
n
3 27 25 6 61 49 34 2 66 5 37 5 38 4 4 21 6 4 48 37 19 16 54 3 22 58 15 18 15 86 23 811
5 5 14 5.5 4 7 8 11.5 6 11 6 11 12.5 4 14.5 28 6.5 5 1 43 10 11.5 7 29 6.5 5 7 6 3 5 7 6
5–6 3–26 7–51 3–8 2–26 264 5–77 8–15 3–120 8–62 3–64 4–23 6–131 2–10 7–53 10–129 3–39 3–9 0–40 2–111 3–79 5–84 3–66 9–70 3–13 3–51 4–25 3–10 2–16 2–26 3–49 0–131
0 2 0 0 2 6 11 0 7 0 2 0 8 0 1 5 1 0 2 2 4 0 5 0 2 5 3 4 1 5 1 79
% of Each Procedure
% of All Readmissions
0 7.4 0 0 3.3 12.2 32.3 0 10.6 0 5.4 0 21 0 25 23.8 16.7 0 4.2 5.4 21 0 9.2 0 9 8.6 20 22.2 6.6 5.8 4.3
0 2.6 0 0 2.6 7.5 14 0 8.8 0 2.6 0 10 0 1.3 6.3 1.3 0 2.6 2.6 5 0 6.3 0 2.6 6.3 3.7 5 1.3 6.3 1.3 100
ALCAPA ¼ anomalous origin of left coronary artery from pulmonary artery; ASD ¼ atrial septal defect; AVSD ¼ atrioventricular septal defect; ICD ¼ implantable cardioverter defibrillator; LOS ¼ length of stay; LVOT ¼ left ventricular outflow tract; PA ¼ pulmonary artery; PA/VSD ¼ pulmonary atresia/ventricular septal defect; PDA ¼ patent ductus arteriosus; RVOT ¼ right ventricular outflow tract; TAPVR ¼ total anomalous pulmonary venous return; TOF ¼ tetralogy of Fallot; VSD ¼ ventricular septal defect.
suggest that aggressive management of rhythm problems before discharge along with early follow-up within a week may be particularly beneficial. Postoperative hospital length of stay is a direct marker of morbidity. Patients with prolonged hospital length of stay typically have other associated comorbid conditions. As an example, pleural effusion is associated with both prolonged hospital stay and readmission. Efforts focusing on diuresis in this particular subgroup may be helpful in reducing readmission. We suggest that early follow-up of these patients, combined with early interventions like changing the diuretic regimen, may be of particular benefit. Although Hispanic ethnicity has previously been identified as a risk factor for readmission because of a language barrier, this was not significant in our patient population even though 17% of our patients were Hispanic.
The most common causes of readmission reported in a prior large single-center study were pleural or pericardial effusion (26%) and gastrointestinal (24%), infectious (19%), and cardiac (15%) conditions [13]. Other prior studies have also reported similar causes [3, 11]. By contrast, the most common cause of readmission in our patients was cardiovascular. Pleural effusion was more frequently associated with Glenn and Fontan procedures and about two thirds of these patients required drainage during readmission. More aggressive diuresis, as suggested earlier, could potentially reduce readmissions in this subgroup. Early follow-up after discharge with a chest roentgenogram and adjustment of diuretic dose could potentially reduce some of the readmissions, given that the median time to readmission was 7 days in our patient population. In light of this, we are instituting
CONGENITAL HEART
All Patients
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Table 5. Continued
Table 5. Summary of Univariate Analysis of Variables Between Nonreadmission and Readmission Groups
CONGENITAL HEART
Nonreadmission Readmission (n ¼ 732) (n ¼ 79) Variable Demographic factors Age at operation 1 year Weight at operation (kg) 10 Gender Male Female Ethnicity White Hispanic Other Preoperative factors Chromosomal abnormality Down DiGeorge syndrome Other syndromes Asplenia/polysplenia Arrhythmia Other cardiovascular factors Mechanical ventilation Tracheostomy Neurologic factors Prematurity Infectious disease factors Gastrointestinal factors Endocrine factors Renal Hematologic factors Other Operative factors Assigned surgeon A B C STAT score 1 2 3 4 5
n
%
n
%
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Nonreadmission Readmission (n ¼ 732) (n ¼ 79) p Value
118 221 393
16 30 54
16 32 31
20 41 39
0.049
193 174 364
26 24 50
23 27 29
29 34 37
0.059
392 340
54 46
43 36
54 36
0.881
558 119 55
76 16 8
57 17 5
72 22 6
0.498
115
16
21
27
0.015
67 29 55 12 38 17
9 4 8 2 5 2
10 3 10 1 7 3
13 4 13 1 9 4
0.315 0.944 0.114 0.802 0.181 0.426
29
4
6
8
0.138
1 27 95 9
0 4 13 1
2 6 13 3
3 8 16 4
0.052 0.102 0.388 0.205
27
4
9
11
0.002
9 15 9 1
1 2 1 0
1 1 1 1
1 1 1 1
1 0.637 1 0.370
585 66 81
80 9 11
71 2 6
89 3 8
0.096
318 225 82 90 17
43 31 11 12 2
17 35 8 14 5
22 44 10 18 6
0.002
Variable Postoperative factors Single ventricle Palliated physiology Mechanical ventilation (days) 5 NG tube feeding at discharge ICU LOS (days) 0 1–2 3–5 >5 Postoperative LOS (days) 1–5 6–10 >10
n
%
n
%
p Value
69 15
9 2
24 4
30 5
