Introduction
Materials and methods
Data collection
ICU organisation
Statistical analysis
Results
Study group characteristics
All patients (n = 2852) | No readmission (n = 2471) | Readmission (n = 381) | p value | |
---|---|---|---|---|
Age, mean ± SD (years) | 62 ± 15 | 61 ± 15 | 64 ± 14 | 0.001 |
Male gender (%) | 1828 (64.1) | 1578 (63.9) | 250 (65.6) | 0.506 |
Source of admission (%) | < 0.001 | |||
Operating room | 2213 (77.6) | 1944 (78.7) | 269 (70.6) | |
Emergency room | 130 (4.6) | 110 (4.5) | 20 (5.2) | |
Other hospital | 169 (5.9) | 136 (5.5) | 33 (8.7) | |
Others | 172 (6.0) | 133 (4.8) | 39 (10.3) | |
Comorbidities (%) | ||||
Cancer | 628 (22.0) | 555 (22.5) | 73 (19.2) | 0.148 |
Cancer therapy | 61 (2.1) | 52 (2.1) | 9 (2.4) | 0.746 |
Haematological cancer | 6 (0.2) | 6 (0.2) | - | 1.000 |
Chronic heart failure (NYHA IV) | 48 (1.7) | 38 (1.5) | 10 (2.6) | 0.125 |
Cirrhosis | 65 (2.3) | 55 (2.2) | 10 (2.6) | 0.627 |
Hypertension | 1437 (50.4) | 1247 (50.5) | 190 (49.9) | 0.828 |
Chronic renal failure | 288 (10.1) | 240 (9.7) | 48 (12.5) | 0.036 |
Diabetes | 617 (21.6) | 522 (21.1) | 95 (24.9) | 0.137 |
Primary diagnosis (%) | 0.024 | |||
Planned postoperative | 2268 (79.5) | 1995 (80.7) | 273 (71.7) | |
Unplanned admissions* | ||||
Trauma | 139 (4.9) | 122 (4.9) | 17 (4.5) | |
Cardiovascular | 124 (4.3) | 92 (3.7) | 32 (8.4) | |
Neurological | 109 (3.8) | 93 (3.8) | 16 (4.2) | |
Gastrointestinal | 64 (2.2) | 49 (2.0) | 15 (3.9) | |
Respiratory | 30 (1.1) | 23 (0.9) | 7 (1.8) | |
Others | 116 (4.1) | 95 (3.8) | 21 (5.5) | |
Sepsis syndromes (%) | 0.018 | |||
SIRS | 642 (22.5) | 552 (22.3) | 90 (23.6) | |
Sepsis | 57 (2.0) | 45 (1.8) | 12 (3.1) | |
Severe sepsis/septic shock | 32 (1.1) | 23 (0.9) | 9 (2.3) | |
Surgery within 24 hours of admission (%) | 2412 (84.6) | 2113 (85.5) | 299 (87.5) | < 0.001 |
Cardiac surgery | 1061 (37.2) | 933 (37.8) | 128 (33.6) | 0.118 |
Gastrointestinal | 564 (19.8) | 486 (19.7) | 78 (20.5) | 0.714 |
Neurosurgery | 415 (14.6) | 361 (14.6) | 54 (14.2) | 0.822 |
Trauma | 169 (5.9) | 149 (6.0) | 20 (5.2) | 0.548 |
Thoracic surgery | 156 (5.5) | 138 (5.6) | 18 (4.7) | 0.492 |
Others** | 104 (3.6) | 98 (3.9) | 7 (1.8) | 0.123 |
Mechanical ventilation | 1339 (49.2) | 1155 (48.9) | 184 (50.9) | 0.503 |
Admission scores, mean ± SD | ||||
TISS-28 score | 41.8 ± 10.7 | 41.7 ± 10.6 | 42.1 ± 11.3 | 0.367 |
SOFA score | 5.1 ± 3.4 | 5.0 ± 3.4 | 5.7 ± 3.5 | 0.001 |
SAPS2 score | 33.5 ± 16.4 | 32.9 ± 16.3 | 37.1 ± 16.4 | < 0.001 |
Characteristics of readmissions to the ICU compared with initial admission
Readmission episodes (n = 476) | Initial admission (n = 381) | First readmission (n = 381) | Second readmission (n = 67) | Third or more readmission (n = 28) | |
---|---|---|---|---|---|
Primary diagnosis | |||||
Planned postoperative | 223 (46.8) | 273 (71.7) | 185 (48.6)$ | 27 (40.3)$ | 11 (39.3)$ |
Unplanned admissions* | 253 (53.2) | 108 (28.3) | 196 (51.4)$ | 40 (59.7)$ | 17 (60.7)$ |
Cardiovascular | 68 (14.3) | 32 (8.4) | 57 (15) | 9 (13.4) | 2 (7.1) |
Trauma | - | 17 (4.5) | - | - | - |
Neurological | 29 (6.1) | 16 (4.2) | 26 (6.8) | 1 (1.5) | 2 (7.1) |
Gastrointestinal | 40 (8.4) | 15 (3.9) | 28 (7.3) | 9 (13.4) | 3 (10.7) |
Respiratory | 62 (13.0) | 7 (1.8) | 46 (12.1) | 13 (19.4) | 3 (10.7) |
Others | 54 (11.3) | 21 (5.5) | 39 (10.2) | 8 (12.0) | 7 (25.1) |
Surgery on the day of admission | 280 (58.8) | 299 (87.5) | 229 (60.1)$ | 34 (50.7)$ | 17 (60.7)$ |
Cardiac surgery | 86 (18.1) | 128 (33.6) | 72 (18.9) | 10 (14.9) | 4 (14.3) |
Gastrointestinal | 86 (18.1) | 78 (20.5) | 59 (15.5) | 15 (22.4) | 12 (42.9)$ |
Neurosurgery | 59 (12.4) | 54 (14.2) | 55 (14.4) | 4 (6.0) | - |
Trauma | - | 20 (5.2) | - | - | - |
Thoracic surgery | 37 (7.8) | 18 (4.7) | 28 (7.3) | 7 (10.4) | 2 (7.1) |
Others** | 22 (4.6) | 7 (1.8) | 21 (5.6) | 1 (1.5) | - |
Admission scores, mean ± SD | |||||
SAPS II score | - | 37.1 ± 16.4 | 37.7 ± 17.2 | 42.3 ± 19.2$ | 40.6 ± 21.2$ |
SOFA score | - | 5.7 ± 3.5 | 5.0 ± 3.6 | 5.6 ± 4.3 | 5.7 ± 3.4 |
TISS-28 score | - | 42.1 ± 11.3 | 38.4 ± 11.4 | 40.4 ± 13.9$ | 38 ± 14.4$ |
SOFAmax | - | 6.1 ± 3.8 | 5.6 ± 4.3$ | 6.3 ± 4.7$ | 6.4 ± 4$ |
Mechanical ventilation | |||||
On ICU admission (%) | 193 (43.4) | 184 (50.8) | 150 (42) | 30 (49.2) | 13 (48.1) |
At any time in the ICU | 240 (53.9) | 206 (54.1) | 187 (52.4) | 38 (62.3) | 15 (53.6) |
Duration, median and range (days) | 2 (1 to 5) | 2 (1 to 4) | 2 (1 to 4) | 5 (1 to 10) | 2 (1 to 5) |
Sepsis during ICU stay (%) | 66 (13.9) | 54 (14.2) | 51 (13.4) | 12 (17.9) | 3 (10.7) |
ICU LOS, median and range (days) | - | 2 (1 to 4) | 2 (1 to 4) | 2 (1 to 10) | 3 (1 to 8)$ |
ICU mortality rate (%) | - | - | 29 (7.6) | 4 (6) | 6 (21.4)$ |
Hospital mortality rate (%) | - | 65 (17.1) | 65 (17.1) | 16 (13.9) | 13 (46.4)$ |
Morbidity and mortality
No readmission (n = 2471) | Readmission (n = 381) | p value | |
---|---|---|---|
Bilirubin (μmol/L) | |||
First | 16 (11 to 23) | 17 (11 to 25) | 0.157 |
Max | 16 (12 to 24) | 19 (12 to 27) | 0.009 |
Last | 13.5 (9 to 19) | 14 (9 to 21) | 0.845 |
Creatinine (μmol/L) | |||
First | 88 (74 to 106) | 94 (79 to 120.5) | < 0.001 |
Max | 89 (75 to 111) | 99 (81 to 129) | < 0.001 |
Last | 83 (70 to 102) | 88 (72 to 119) | 0.002 |
Leucocyte count (103/μl) | |||
First | 12.0 (9.1 to 15.5) | 12.6 (9.5 to 16.6) | 0.027 |
Max | 12.5 (9.6 to 16.2) | 13.4 (10.1 to 17.9) | 0.002 |
Last | 10.4 (8.2 to 13.8) | 10.5 (8.1 to 14) | 0.720 |
Platelet count (103/μl) | |||
First | 169 (127 to 224) | 167 (125 to 222) | 0.628 |
Min | 159 (119 to 212) | 150 (113 to 206) | 0.061 |
Last | 176 (133 to 236) | 173 (130 to 242) | 0.999 |
Lactate (mmol/L) | |||
First | 1.7 (1.2 to 1.6) | 1.9 (1.2 to 3) | 0.007 |
Max | 1.8 (1.2 to 2.8) | 2 (1.3 to 3.3) | 0.004 |
Last | 0.9 (1.3 to 1.8) | 1.2 (0.9 to 1.7) | 0.526 |
C-reactive protein (mg/L) | |||
First | 64.8 (33.4 to 102) | 71.8 (34 to 113) | 0.138 |
Max | 93.5 (49.2 to 174.6) | 125 (63.8 to 207.1) | < 0.001 |
Last | 77 (38.9 to 131) | 84 (40.7 to 158) | 0.028 |
Risk factors for readmission to the ICU
Univariate | Multivariate | |||
---|---|---|---|---|
Odds ratio (95% CI) | p value | Odds ratio (95% CI) | p value | |
Age (per 10 years) | 1.14 (1.06 to 1.23) | 0.001 | 1.13 (1.03 to 1.24) | 0.025 |
Female gender | 1.08 (0.86 to 1.36) | 0.506 | 0.86 (0.59 to 1.24) | 0.404 |
Source of admission | ||||
Operating room | Reference | NA | Reference | NA |
Emergency room | 1.31 (0.80 to 2.15) | 0.278 | 1.51 (0.59 to 3.84) | 0.385 |
Other hospital | 1.75 (1.17 to 2.62) | 0.006 | 1.35 (0.60 to 3.05) | 0.472 |
Cancer | 0.82 (0.62 to 1.07) | 0.148 | 1.05 (0.63 to 1.76) | 0.845 |
Chronic heart failure | 1.73 (0.85 to 3.49) | 0.129 | 1.13 (0.43 to 2.94) | 0.806 |
Chronic renal failure | 1.34 (0.96 to 1.87) | 0.083 | 1.17 (0.72 to 1.91) | 0.591 |
Diabetes | 1.24 (0.97 to 1.59) | 0.093 | 1.47 (0.99 to 2.16) | 0.054 |
Unplanned admissions | 1.66 (1.30 to 2.12) | < 0.001 | 0.84 (0.42 to 1.68) | 0.612 |
Sepsis during initial ICU stay | ||||
No sepsis | Reference | NA | Reference | NA |
Sepsis | 1.46 (0.95 to 2.25) | 0.083 | 1.18 (0.73 to 1.90) | 0.494 |
Severe sepsis | 1.44 (0.86 to 2.41) | 0.171 | 1.04 (0.58 to 1.86) | 0.901 |
Type of surgery | ||||
Neurosurgery | 0.97 (0.71 to 1.31) | 0.822 | 0.97 (0.56 to 1.70) | 0.923 |
Thoracic surgery | 0.84 (0.51 to 1.39) | 0.492 | 1.30 (0.56 to 3.06) | 0.543 |
Cardiac surgery | 0.83 (0.66 to 1.05) | 0.118 | 0.71 (0.44 to 1.15) | 0.166 |
Gastrointestinal | 1.05 (0.80 to 1.37) | 0.714 | 0.82 (0.56 to 1.65) | 0.654 |
Trauma | 0.86 (0.53 to 1.39) | 0.548 | 0.79 (0.32 to 1.92) | 0.601 |
Weekend discharge | 0.79 (0.74 to 1.82) | 0.175 | 0.84 (0.61 to 1.34) | 0.575 |
Nocturnal discharge | 0.93 (0.47 to 1.22) | 0.375 | 0.98 (0.74 to 1.22) | 0.442 |
Severity scores (per point)* | ||||
SAPS 2 score** | 1.02 (1.01 to 1.02) | < 0.001 | 1.03 (0.99 to 1.07) | 0.155 |
SOFA score** | 1.06 (1.02 to 1.09) | 0.001 | 1.03 (0.99 to 1.07) | 0.138 |
SOFAmax | 1.06 (1.03 to 1.10) | < 0.001 | 1.04 (1.01 to 1.08) | 0.045 |
Mechanical ventilation during ICU stay | 1.04 (0.82 to 1.31) | 0.772 | 1.05 (0.78 to 1.41) | 0.765 |
Duration of mechanical ventilation (per day) | 1.04 (1.01 to 1.06) | 0014 | 1.02 (0.98 to 1.05) | 0.421 |
Laboratory parameters on the day of initial discharge † | ||||
Bilirubin (μmol/L) | 0.98 (0.98 to 1.01) | 0.558 | 1 (0.99 to 1.04) | 0.939 |
Creatinine (μmol/L) | 1.02 (1.01 to 1.03) | 0.04 | 1.01 (1 to 1.03) | 0089 |
Leucocyte count (103/μl) | 1.01 (0.98 to 1.03) | 0.503 | 1.02 (0.99 to 1.05) | 0.3 |
Platelet count (103/μl) | 1 (0.99 to 1.01) | 0.445 | 1 (0.99 to 1.02) | 0.543 |
Lactate (mmol/L) | 0.94 (0.84 to 1.06) | 0.308 | 0.95 (0.84 to 1.07) | 0.413 |
C-reactive protein (mg/L) | 1.01 (1.01 to 1.02) | 0.003 | 1.02 (1.01 to 1.04) | 0.035 |
Predictors of worse outcome in patients readmitted to the ICU
Univariate | Multivariate | |||
---|---|---|---|---|
Odds ratio (95% CI) | p value | Odds ratio (95% CI) | p value | |
Age (per 10 years) | 1.18 (0.97 to 1.44) | 0.108 | - | - |
Female | 0.98 (0.89 to 1.21) | 0.205 | - | - |
Source of admission | ||||
Operating room | Reference | NA | - | - |
Emergency room | 1.21 (0.39 to 3.79) | 0.741 | - | - |
Other hospital | 1.08 (0.42 to 2.76) | 0.877 | - | - |
Cancer | 2.21 (1.21 to 4.03) | 0.010 | 1.69 (0.81 to 3.53) | 0.161 |
Chronic heart failure | 1.22 (0.25 to 5.89) | 0.803 | - | - |
Cirrhosis | 1.22 (0.25 to 5.89) | 0.803 | - | - |
Chronic renal failure | 2.57 (1.30 to 5.08) | 0.006 | 2.39 (1.10 to 5.20) | 0.028 |
Diabetes | 1.30 (0.72 to 2.36) | 0.380 | - | - |
Unplanned admissions | 0.88 (0.48 to 1.60) | 0.667 | - | - |
Sepsis during initial ICU stay | ||||
No sepsis | Reference | NA | - | - |
Sepsis | 1.44 (0.60 to 3.48) | 0.419 | - | - |
Severe sepsis | 0.64 (0.18 to 2.34) | 0.501 | - | - |
Type of surgery | ||||
Neurosurgery | 0.35 (0.12 to 1.00) | 0.051 | 0.46 (0.14 to 1.48) | 0.193 |
Thoracic surgery | 1.42 (0.45 to 4.44) | 0.553 | - | - |
Cardiac surgery | 0.49 (0.26 to 0.92) | 0.026 | 0.54 (0.23 to 1.25) | 0.149 |
Gastrointestinal | 3.39 (1.90 to 6.04) | < 0.001 | 2.60 (1.17 to 5.80) | 0.020 |
Trauma | 2.19 (0.81 to 5.94) | 0.122 | 2.27 (0.72 to 7.18) | 0.165 |
Time to readmission | ||||
Within 48 hours | References | NA | Reference | NA |
2 to 7 days | 1.05 (0.42 to 2.66) | 0.914 | 0.81 (0.34 to 2.26) | 0.792 |
> 7 days | 2.02 (0.81 to 5.02) | 0.131 | 1.73 (0.69 to 4.37) | 0.245 |
Severity scores (per point) * | ||||
SAPS 2 score ** | 1.02 (1.01 to 1.03) | 0.043 | 1.02 (1.01 to 1.04) | 0.045 |
SOFA score ** | 1.04 (0.97 to 1.13) | 0.276 | 1.07 (0.98 to 1.16) | 0.163 |
SOFAmax | 1.03 (0.96 to 1.11) | 0.382 | 1.05 (0.97 to 1.14) | 0.231 |
Discussion
Conclusion
Key messages
-
In this large cohort of surgical ICU patients, 13.4% of patients discharged from the ICU required readmission during the same hospitalisation.
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Readmission to the ICU was associated with a more than five-fold increase in hospital mortality.
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Older age, higher SOFAmax score and greater CRP concentrations on the day of discharge to the hospital floor were independently associated with a higher risk of readmission to the ICU.