Background
Methods
Participants
Defining anaemia
Outcome measurements
Morbidity type | C-POMS criteria |
---|---|
Pulmonary | Presence of one or more of the following: ■ New requirement for oxygen or respiratory support (including nebuliser therapy or request for chest physiotherapy on or after D5) ■ Pleural effusion requiring drainage |
Infectious | Presence of one or more of the following: ■ Currently on antibiotics ■ A temperature of >38 °C in the last 24 h ■ A white cell count/CRP level requiring in-hospital review or treatment |
Renal | Presence of one or more of the following: ■ Decreased urine output requiring intervention (including IV furosemide) ■ Increased serum creatinine (>30% from pre-operative level) ■ Urinary catheter in situ ■ New urinary incontinence ■ Serum potassium abnormalities requiring treatment |
Gastrointestinal | Presence of one or more of the following: ■ Unable to tolerate an enteral diet for any reason including nausea, vomiting and abdominal distension ■ The presence of a nasogastric tube ■ Diagnosis of a gastrointestinal bleed ■ Diarrhoea |
Cardiovascular | Presence of one or more of the following: ■ The use of inotropic therapy for any cardiovascular cause ■ Pacing wires (on or after D5) and/or requiring temporary or new permanent pacing ■ Diagnostic tests or therapy within the last 24 h for any of the following: (1) new MI or ischaemia, (2) hypotension (requiring fluid therapy, pharmacological therapy or omission of pharmacological therapy), (3) atrial or ventricular arrhythmias, (4) cardiogenic pulmonary oedema, thrombotic event (requiring anticoagulation), (5) hypertension (pharmacological therapy or omission of pharmacological therapy) |
Neurological | New neurological deficit (including confusion, delirium, coma, lack of coordination, drowsy/slow to wake, poor swallow, blurred vision, sedated, changing loss of consciousness) |
Haematological | Presence of one or more of the following: ■ Untherapeutic INR requiring pharmacological therapy or omission of pharmacological therapy ■ Requirement for any of the following within the last 24 h: packed erythrocytes, platelets, fresh-frozen plasma or cryoprecipitate |
Wound | Presence of one or more of the following: ■ Wound dehiscence requiring surgical exploration or drainage of pus from the operation wound with or without isolation of organisms ■ Chest drains ■ Wound pain significant enough to require continuing or escalating analgesic intervention |
Pain | Post-operative pain significant enough to require parenteral opioids and/or continuing or additional analgesia. |
Endocrine | New or additional requirements for blood sugar management |
Electrolyte | Electrolyte (including sodium, urea, phosphate) imbalance requiring oral or intravenous intervention (not including potassium as included in renal category) |
Review | Remaining in hospital for further review, investigation and/or procedure |
Assisted ambulation | A new or escalated post-operative requirement for mobility assistance (including wheelchair, crutches, zimmer frame, walking sticks or assistance) |
Non-C-POMS related reasons for delayed discharge on D5, D8 and D15 which the PDG decided should also be routine data collection in C-POMS on these days. | |
Non-morbidity reason for delayed discharge | Where C-POMS is ‘0’ but the patient remains in hospital, state the reason for lack of discharge:
Social reasons; Equipment at home; Mobility (ongoing physic and OT needs); Institutional failure (transport not booked, OPA or follow-up not arranged); Delayed discharge (lack of rehab or other bed); Discharge planned for today; Other medical reason
|
RBC transfusion
Total morbidity burden: C-POMS summary score
Post-operative length of stay
Other clinical data
Overall | Anaemic | Not anaemic |
P (anaemic vs not anaemic) | |
---|---|---|---|---|
(n = 442) | (n = 139) | (n = 303) | ||
Frequency (%)/mean ± SD | Frequency (%)/mean ± SD | Frequency (%)/mean ± SD | ||
Demographics | ||||
Age (mean/years) | 66.5 ± 10.6 | 69.5 ± 10.5 | 65.11 ± 10.4 | 0.000 |
Female gender | 92 (20.8) | 32 (23.0) | 60 (19.8) | 0.451 |
Ethnicity (White British) (n = 438) | 377 (86.1) | 106 (76.8) | 271 (90.3) | 0.001 |
Medical history | ||||
Renal (dialysis) | 7 (1.6) | 6 (4.3) | 1 (0.3) | 0.005 |
History of previous MI (n = 415) | 147 (35.4) | 49 (38.0) | 98 (34.3) | 0.375 |
Re-operation | 18 (4.1) | 8 (5.8) | 10 (3.3) | 0.299 |
Cerebrovascular accident | 16 (3.6) | 9 (6.5) | 7 (2.3) | 0.050 |
Gastrointestinal disease | 50 (11.3) | 23 (16.5) | 2 (8.9) | 0.023 |
Congestive heart failure (n = 415) | 13 (3.1) | 8 (6.2) | 5 (1.7) | 0.034 |
Symptoms | ||||
NYHA class (n = 441) | ||||
- I | 114 (25.9) | 32 (23.0) | 82 (27.2) | 0.245 |
- II | 204 (46.3) | 65 (46.8) | 139 (46.0) | |
- III | 101 (22.9) | 31 (22.3) | 70 (23.2) | |
- IV | 22 (5.0) | 11 (2.5) | 11 (3.6) | |
Cardiac risk factors | ||||
Smoking | ||||
- Current | 49 (11.1) | 14 (10.1) | 35 (11.6) | 0.891 |
- Ex | 244 (55.2) | 77 (55.4) | 167 (55.1) | |
- Never | 149 (33.7) | 48 (34.5) | 101 (33.3) | |
Hypertension | 302 (68.3) | 95 (68.3) | 207 (68.3) | 1.000 |
Hypercholesteraemia | 341 (77.1) | 101 (72.7) | 240 (79.5) | 0.142 |
Diabetes | 103 (23.3) | 53 (38.1) | 50 (16.5) | 0.000 |
BMI (kg/m2)/mean | 28.6 ± 5.7 | 28.1 ± 6.0 | 28.8 ± 5.5 | 0.262 |
Examination and investigation | ||||
LVEF (n = 434) | ||||
- Good | 323 (74.4) | 101 (74.3) | 222 (74.5) | 0.167 |
- Fair | 88 (20.3) | 24 (17.6) | 64 (21.5) | |
- Poor | 23 (5.3) | 11 (8.1) | 12 (4.0) | |
Number diseased vessels (n = 435) | ||||
- 0 | 79 (18.2) | 28 (20.6) | 51 (17.1) | 0.799 |
- 1 | 34 (7.8) | 10 (7.4) | 24 (8.0) | |
- 2 | 80 (18.4) | 26 (19.1) | 54 (18.1) | |
- 3 | 242 (55.6) | 72 (52.9) | 170 (56.9) | |
Pre-operative risk assessment | ||||
EuroSCORE (median [IQR]) | 4 [1–5] | 5 [2–6] | 3 [1–4] | 0.000 |
Intra-operative details | ||||
Operative priority | ||||
-Elective | 308 (69.7) | 73 (52.5) | 235 (77.6) | 0.000 |
Operation performed | ||||
- CABG | 298 (67.4) | 86 (61.9) | 212 (70.0) | 0.103 |
- AVR | 61 (13.8) | 18 (12.9) | 43 (14.2) | |
- MVR | 10 (2.3) | 5 (3.6) | 5 (1.7) | |
- CABG + AVR | 35 (7.9) | 14 (10.1) | 21 (6.9) | |
- CABG + MVR | 0 (0.0) | 0 (0.0) | 0 (0.0) | |
- AVR + MVR | 3 (0.7) | 0 (0.0) | 3 (1.0) | |
- CABG + AVR + MVR | 2 (0.5) | 0 (0.0) | 2 (0.7) | |
- Other | 33 (7.5) | 16 (11.5) | 17 (5.6) | |
Duration of operation (min) | 224.0 ± 54.1 | 230.3 ± 64.5 | 221.0 ± 48.3 | 0.098 |
Cardiopulmonary bypass used | 410 (93.4) | 139 (92.8) | 281 (93.7) | 0.837 |
Cardiopulmonary bypass time (n = 428) | 79.0 ± 35.8 | 80.8 ± 41.6 | 78.2 ± 32.8 | 0.495 |
Aortic cross clamp time | 51.0 ± 24.9 | 52.7 ± 29.5 | 50.26 ± 22.6 | 0.362 |
Outcome | ||||
Number of hours ventilated (h) (n = 392) | 9.84 ± 58.2 | 8.0 ± 6.6 | 10.6 ± 69.3 | 0.690 |
Length of ICU stay (mean/days) (n = 416) | 2.0 ± 3.5 | 3.0 ± 5.7 | 1.6 ± 1.6 | 0.000 |
Readmitted to ICU | 15 (3.4) | 11 (8.4) | 4 (1.4) | 0.001 |
Return to theatre | 21 (4.8) | 13 (9.6) | 8 (2.7) | 0.003 |
Total length of hospital stay (mean/days) | 11.8 ± 11.7 | 15.2 ± 17.2 | 10.2 ± 7.6 | 0.000 |
Statistical analysis
Results
Baseline characteristics
Pre-operative anaemia
Pre-operative anaemia and RBC transfusion
C-POMS morbidity domain | OR (95%CI)a
|
p value | Bonferroni adjusted p value |
---|---|---|---|
Pulmonary | 3.55 (1.87–6.73) | 0.0001 | 0.001 |
Infectious | 1.71 (0.71–4.15) | 0.232 | 1.00 |
Renal | 4.52 (1.88–10.83) | 0.001 | 0.013 |
Gastrointestinal | 2.58 (1.42–4.68) | 0.002 | 0.026 |
Cardiovascular | 4.14 (1.37–12.47) | 0.012 | 0.156 |
Neurological | 5.89 (2.65–13.09) | 0.00001 | 0.0001 |
Haematological | 2.98 (1.20–7.41) | 0.019 | 0.247 |
Wound | 1.89 (0.66–5.40) | 0.237 | 1.000 |
Pain | 1.39 (0.51–3.78) | 0.514 | 1.000 |
Endocrine | 4.40 (1.97–9.84) | 0.0003 | 0.004 |
Electrolyte | 0.66 (0.14–3.08) | 0.594 | 1.000 |
Review | 1.97 (1.06–3.64) | 0.032 | 0.416 |
Assisted ambulation | 6.49 (2.57–16.40) | 0.00008 | 0.001 |
Pre-operative anaemia and C-POMS score
C-POMS morbidity domain | OR (95%CI)a
|
p value | Bonferroni adjusted p value |
---|---|---|---|
Pulmonary | 1.60 (0.93–2.76) | 0.088 | 1.00 |
Infectious | 1.87 (0.84–4.17) | 0.125 | 1.00 |
Renal | 6.88 (2.97–15.92) | 0.000006 | 0.00008 |
Gastrointestinal | 0.89 (0.52–1.53) | 0.674 | 1.000 |
Cardiovascular | 1.64 (0.62–4.31) | 0.319 | 1.000 |
Neurological | 0.81 (0.40–1.66) | 0.571 | 1.000 |
Haematological | 1.35 (0.60–3.03) | 0.467 | 1.000 |
Wound | 2.12 (0.80–5.62) | 0.133 | 1.000 |
Pain | 1.53 (0.63–3.75) | 0.349 | 1.000 |
Endocrine | 2.83 (1.38–5.80) | 0.005 | 0.065 |
Electrolyte | 2.73 (0.70–10.68) | 0.150 | 1.000 |
Review | 1.22 (0.68–2.20) | 0.510 | 1.000 |
Assisted ambulation | 4.96 (2.16–11.38) | 0.0002 | 0.0026 |
Model including anaemia | Model including Hb | ||||
---|---|---|---|---|---|
B (se) |
p value |
B (se) |
p value | ||
Age | 10-year increase | −0.15 (0.10) | 0.13 | −0.16 (0.10) | 0.11 |
Gender | Female/male | −0.15 (0.22) | 0.49 | −0.34 (0.23) | 0.13 |
EuroSCORE | Per quintile | 0.48 (0.08) | <0.0001 | 0.48 (0.08) | <0.0001 |
Anaemia | Yes/no | 0.55 (0.20) | 0.005 | – | – |
Hb | 1 SD increase | – | – | −0.29 (0.10) | 0.003 |
Transfusion | Yes/no | 1.23 (0.22) | <0.0001 | 1.19 (0.22) | <0.0001 |
Pre-operative anaemia and hospital LOS
Quintile | D3 | D5 | D8 | D15 | All time points | Hospital LOS |
---|---|---|---|---|---|---|
Median [IQR] | Median [IQR] | Median [IQR] | Median [IQR] |
B
a (se) | Median [IQR] | |
1 (≤121) | 5 [2–6] 90 | 3 [1–5] 87 | 4 [2–6] 54 | 4 [2–7.5] 20 | 0 | 10 [6–17.5] 88 |
2 (122–131) | 4 [2–5] 93 | 2 [1–4] 90 | 3 [2–4] 43 | 3 [2–3] 7 | −0.82 (0.29) | 7.5 [6–11] 90 |
3 (132–138) | 2 [1–5] 82 | 2 [1–3] 80 | 3 [1–4] 31 | 2 [2–6] 7 | −1.34 (0.30) | 6.5 [5–10] 82 |
4 (139–146) | 3 [1–5] 89 | 2 [1–3] 82 | 3 [2–5] 29 | 3 [1–4] 6 | −1.25 (0.29) | 6 [5–9] 88 |
5 (>146) | 2 [1–4] 85 | 2 [1–3] 78 | 3 [1–4] 19 | 2.5 [1.5–3] 4 | −1.71 (0.29) | 6 [5–8] 86 |
p value | <0.0001 | 0.007 | 0.28 | 0.67 | <0.0001 | <0.0001 |
p value (trend) | <0.0001 | 0.001 | 0.16 | 0.15 | <0.0001 | <0.0001 |
Model including anaemia | Model including Hb | ||||
---|---|---|---|---|---|
OR (95%CI) |
p value | OR (95%CI) |
p value | ||
Age | 10-year increase | 0.77 (0.64–0.94) | 0.009 | 0.76 (0.63–0.92) | 0.006 |
Gender | Female/male | 1.24 (0.80–1.91) | 0.34 | 1.01 (0.65–1.57) | 0.95 |
EuroSCORE | Per quintile | 1.85 (1.57–2.19) | <0.0001 | 1.83 (1.55–2.16) | <0.0001 |
Hb | Yes/no | – | – | 0.71 (0.59–0.86) | 0.001 |
Anaemia | 1 SD increase | 1.65 (1.12–2.44) | 0.01 | – | – |
Transfusion | Yes/no | 2.40 (1.55–3.72) | <0.0001 | 2.25 (1.45–3.49) | 0.0003 |