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Table 4 Effects of age, sex, surgical status, APACHE II physiological variables, serum albumin and number of organ system failures on ultimate hospital outcome in patients requiring chronic renal dialysis

From: Case mix, outcome and activity for patients admitted to intensive care units requiring chronic renal dialysis: a secondary analysis of the ICNARC Case Mix Programme Database

Parameter

Patients requiring chronic renal dialysis

Admissions not requiring chronic renal dialysis

 

Deaths

n

(%)

Adjusted OR (95% CI)

P valuee

Adjusted OR (95% CI)

P valuef

Age (years)*

   

1.28 (1.20–1.36)

< 0.001

1.50 (1.49–1.52)

<0.001

   < 45

223

681

(32.8)

per 10-year increase

 

per 10-year increase

 

   45–54

234

499

(46.9)

    

   55–64

314

711

(44.2)

    

   65–74

398

805

(49.4)

    

   75+

210

351

(59.8)

    

Sex

    

0.145

 

0.653

   Female

546

1,220

(44.8)

Reference

 

Reference

 

   Male

833

1,827

(45.6)

1.15 (0.95–1.38)

 

1.10 (1.07–1.12)

 

Surgical status*

    

< 0.001

 

<0.001

   Elective surgery

124

548

(22.6)

Reference

 

Reference

 

   Emergency surgery

194

486

(39.9)

1.69 (1.23–2.32)

 

2.49 (2.40–2.59)

 

   Nonsurgical

1,061

2,012

(52.7)

2.10 (1.59–3.78)

 

3.83 (3.69–3.97)

 

Past medical history*

    

0.042

 

0.111

   Absent

1,121

2,563

(43.7)

Reference

 

Reference

 

   Present

258

484

(53.3)

1.29 (1.01–1.64)

 

1.57 (1.52–1.62)

 

CPR before admission*

    

< 0.001

 

0.424

   No

1,083

2,621

(41.3)

Reference

 

Reference

 

   Yes

295

423

(69.7)

1.90 (1.44–2.52)

 

2.14 (2.05–2.22)

 

LOS before admission (days)*

    

< 0.001

 

0.053

   0

378

863

(43.8)

Reference

 

Reference

 

   1–2

198

595

(33.3)

0.76 (0.58–1.00)

 

0.99 (0.96–1.02)

 

   2–3

94

240

(39.2)

0.98 (0.69–1.40)

 

1.09 (1.04–1.14)

 

   3–6

197

448

(44.0)

0.95 (0.71–1.27)

 

1.29 (1.24–1.34)

 

   7+

511

900

(56.8)

1.95 (1.52–2.49)

 

1.86 (1.80–1.93)

 

Temperaturea (°C)

    

0.783

 

0.078

   < 34

80

126

(63.5)

1.24 (0.77–1.99)

 

1.96 (1.84–2.08)

 

   34–36

456

946

(48.2)

1.05 (0.85–1.30)

 

1.23 (1.19–1.26)

 

   36–38.5

465

1,208

(38.5)

Reference

 

Reference

 

   38.5–39

120

274

(43.8)

1.16 (0.85–1.59)

 

0.95 (0.91–0.98)

 

   ≥ 39

193

382

(50.5)

1.13 (0.84–1.51)

 

1.10 (1.06–1.13)

 

Mean arterial pressurea (mmHg)*

    

< 0.001

 

<0.001

   < 50

410

596

(68.8)

1.96 (1.36–2.83)

 

1.96 (1.87–2.04)

 

   50–70

575

1,189

(48.4)

1.29 (0.95–1.75)

 

1.21 (1.17–1.25)

 

   70–110

117

351

(33.3)

Reference

 

Reference

 

   110–130

144

496

(29.0)

0.74 (0.52–1.05)

 

0.96 (0.92–1.00)

 

   ≥ 130

100

357

(28.0)

0.62 (0.42–0.92)

 

1.26 (1.20–1.32)

 

Heart rateb (beats/min)*

    

< 0.001

 

0.638

   < 50

86

168

(51.2)

1.34 (0.88–2.06)

 

1.15 (1.08–1.22)

 

   50–100

242

780

(31.0)

Reference

 

Reference

 

   100–110

170

446

(38.1)

1.23 (0.92–1.64)

 

1.11 (1.07–1.16)

 

   110–120

228

486

(46.9)

1.57 (1.18–2.08)

 

1.37 (1.32–1.42)

 

   120–140

373

697

(53.5)

1.81 (1.40–2.36)

 

1.72 (1.66–1.77)

 

   140–155

137

241

(56.9)

1.86 (1.30–2.66)

 

2.15 (2.06–2.24)

 

   ≥ 155

107

162

(66.0)

2.09 (1.35–3.23)

 

2.52 (2.40–2.64)

 

Respiratory rateb (breaths/min)*

    

< 0.001

 

0.082

   < 6

63

121

(52.1)

0.99 (0.60–1.64)

 

1.22 (1.15–1.30)

 

   6–12

357

881

(40.5)

1.11 (0.84–1.46)

 

1.07 (1.04–1.11)

 

   12–14

230

496

(46.4)

1.38 (1.01–1.88)

 

1.23 (1.19–1.27)

 

   14–25

207

503

(41.2)

Reference

 

Reference

 

   25–35

269

627

(42.9)

1.13 (0.84–1.51)

 

0.99 (0.96–1.03)

 

   35–40

115

190

(60.5)

2.11 (1.40–3.18)

 

1.25 (1.19–1.32)

 

   ≥ 40

96

148

(64.9)

2.32 (1.46–3.68)

 

1.49 (1.41–1.56)

 

Oxygenationb (mmHg)*

    

0.025

 

0.003

   A-aDO2 (FiO2 ≥ 0.5)

       

< 250

92

182

(50.6)

Reference

 

Reference

 

250–350

187

332

(56.3)

1.28 (0.96–1.72)

 

1.28 (1.24–1.32)

 

350–500

109

200

(54.5)

0.73 (0.49–1.07)

 

1.56 (1.48–1.63)

 

≥ 500

164

242

(67.8)

1.26 (0.87–1.84)

 

1.70 (1.63–1.77)

 

   PaO2 (FiO2 < 0.5)

       

< 50

33

61

(54.1)

1.53 (0.80–2.93)

 

1.06 (0.97–1.16)

 

50–70

130

295

(44.1)

1.04 (0.77–1.41)

 

0.95 (0.92–0.99)

 

70–80

128

343

(37.3)

0.78 (0.58–1.04)

 

0.91 (0.87–0.94)

 

≥ 80

352

846

(41.6)

Reference

 

Reference

 

Arterial pHa*

    

< 0.001

 

0.985

   < 7.15

156

190

(82.1)

2.65 (1.68–4.18)

 

2.95 (2.78–3.13)

 

   7.15–7.25

157

248

(63.3)

1.53 (1.08–2.16)

 

1.65 (1.59–1.72)

 

   7.25–7.33

248

544

(45.6)

1.16 (0.92–1.47)

 

1.20 (1.16–1.23)

 

   7.33–7.5

559

1,380

(40.5)

Reference

 

Reference

 

   ≥ 7.5

79

153

(51.6)

1.40 (0.95–2.07)

 

1.40 (1.33–1.48)

 

Serum sodiuma (mmol/l)*

    

0.035

 

0.079

   < 130

174

331

(52.6)

1.44 (1.09–1.90)

 

1.43 (1.37–1.48)

 

   130–150

1,069

2,468

(43.3)

Reference

 

Reference

 

   ≥ 150

41

64

(64.1)

1.12 (0.61–2.07)

 

2.26 (2.14–2.39)

 

Serum potassiuma (mmol/l)

    

0.180

 

<0.001

   < 3

68

125

(54.4)

1.15 (0.74–1.78)

 

1.09 (1.04–1.14)

 

   3–3.5

199

379

(52.5)

1.16 (0.89–1.52)

 

0.99 (0.96–1.02)

 

   3.5–5.5

658

1,482

(44.4)

Reference

 

Reference

 

   5.5–6

143

351

(40.7)

0.91 (0.68–1.21)

 

1.26 (1.19–1.32)

 

   6–7

145

370

(39.2)

0.74 (0.55–0.99)

 

1.39 (1.31–1.48)

 

   ≥ 7

68

153

(44.4)

0.84 (0.55–1.28)

 

1.40 (1.25–1.56)

 

Serum creatininea (mg/100 ml)

    

0.295

 

0.095

   < 1.5

21

73

(28.8)

Reference

 

Reference

 

   1.5–2

28

67

(41.8)

0.55 (0.28–1.08)

 

1.05 (1.02–1.09)

 

   2–3.5

152

307

(49.5)

0.90 (0.58–1.39)

 

1.37 (1.32–1.42)

 

   ≥ 3.5

1,048

2,365

(44.3)

0.80 (0.55–1.15)

 

1.25 (1.18–1.32)

 

Serum albuminb (g/l)*

    

< 0.001

 

0.060

   < 20

453

823

(55.0)

1.50 (1.20–1.87)

 

1.37 (1.34–1.41)

 

   20–25

239

501

(47.7)

1.35 (1.05–1.72)

 

1.00 (0.97–1.03)

 

   ≥ 25

350

990

(35.4)

Reference

 

Reference

 

Haematocrita (%)

    

0.133

 

0.002

   < 20

164

324

(50.6)

0.70 (0.49–1.01)

 

1.26 (1.18–1.34)

 

   20–30

790

1,769

(44.7)

0.86 (0.70–1.06)

 

1.16 (1.14–1.19)

 

   ≥ 30

326

751

(43.4)

Reference

 

Reference

 

White blood counta (× 1,000/mm3)*

    

0.021

 

0.884

   < 3

92

129

(71.3)

2.02 (1.26–3.25)

 

1.70 (1.60–1.79)

 

   3–15

586

1,577

(37.2)

Reference

 

Reference

 

   15–20

252

533

(47.3)

1.05 (0.83–1.33)

 

1.13 (1.10–1.17)

 

   20–40

287

508

(56.5)

1.28 (1.00–1.64)

 

1.26 (1.22–1.30)

 

   ≥ 40

32

48

(66.7)

1.34 (0.67–2.70)

 

1.38 (1.25–1.53)

 

Glasgow Coma Scorec*

   

1.12 (1.09–1.15)

< 0.001

1.09 (1.09–1.09)

0.067

   3–6

360

466

(77.3)

per decrease of 1

 

per decrease of 1

 

   7–9

73

138

(52.9)

    

   10–12

77

161

(47.8)

    

   13–15

756

2,044

(37.0)

    

Organ system failuresd*

   

1.25 (1.07–1.46)

0.005

1.31 (1.28–1.33)

0.561

   0

289

1,036

(27.9)

per increase of 1

 

per increase of 1

 

   1

469

1,077

(43.6)

    

   2

413

662

(62.4)

    

   3+

208

272

(76.5)

    

Sepsis*

    

0.022

 

0.060

   No

785

2,035

(38.6)

Reference

 

Reference

 

   Yes

594

1,012

(58.7)

1.28 (1.04–1.57)

 

1.04 (1.02–1.07)

 
  1. A total of 2,922 patients are included in this analysis. Significant factors (P < 0.05) in the model for admissions of patients requiring chronic renal dialysis are highlighted by asterisks. Exclusions are as follows: readmissions within the same hospital stay; and admissions missing age, sex, surgical status, temperature, mean arterial pressure, heart rate or respiratory rate. Those admissions with missing values for any other physiological variables were assumed to be normal and placed in the reference category. aCategories from Acute Physiology and Chronic Health Evaluation (APACHE) II (reference category equivalent to zero APACHE II points). bCategories from APACHE III (reference category equivalent to zero APACHE III points). cPre-sedation values used for admissions sedated or paralyzed during the first 24 hours in intensive care unit (ICU). dOrgan system failures assessed physiologically, in accordance with the method of Knaus and coworkers [10]. eP value for significance of factor in the end-stage renal failure (ESRF) model. fP value for difference between ESRF and non-ESRF models (test of interaction). A-aDO2, alveolar-arterial oxygen difference; CI, confidence interval; CPR, cardiopulmonary resuscitation; FiO2, fractional inspired oxygen; LOS, length of stay; OR, odds ratio; PaO2, arterial oxygen tension.
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