Community-acquired versus hospital-acquired acute kidney injury in patients with acute exacerbation of COPD requiring hospitalization in China

Figures & data

Figure 1 Flowchart for patient selection.

Abbreviations: AECOPD, acute exacerbations of COPD; AKI, acute kidney injury; CKD, chronic kidney disease.

Table 1 Demographic data: CA-AKI versus HA-AKI

Variables	CA-AKI (n = 280)	HA-AKI (n = 97)	P-value
Age (years)	81 (77–86)	83 (76–87)	0.12
Men, n (%)	214 (76.4)	76 (79.2)	0.58
Peak serum creatinine (μmol/L)	137 (122–182)	143 (119–194)	0.85
Nephrology consultation (%)	26 (9.3)	11 (11.5)	0.54
AKI severity, n (%)
Stage 1	175 (62.5)	58 (59.8)	0.64
Stage 2	75 (26.8)	18 (18.6)	0.11
Stage 3	30 (10.7)	21 (21.6)	0.007
Complications, n (%)
Acute respiratory failure	122 (43.6)	44 (45.8)	0.70
Hypercapnic encephalopathy	24 (8.6)	8 (8.3)	1.00
Comorbidity, n (%)
Chronic cor pulmonale	117 (41.8)	59 (61.5)	0.001
Pulmonary arterial hypertension	9 (3.2)	7 (7.3)	0.14
Atrial fibrillation	43 (15.4)	16 (16.7)	0.76
Hypertension	169 (60.4)	56 (58.3)	0.73
Diabetes mellitus	56 (20.0)	17 (17.7)	0.62
Coronary artery disease	122 (43.6)	38 (39.6)	0.50
Chronic kidney disease	61 (21.8)	10 (10.4)	0.015
Chronic liver disease	12 (4.3)	4 (4.2)	1.00
Anemia	121 (43.2)	39 (40.6)	0.66
Cerebrovascular disease	77 (27.5)	22 (22.9)	0.38
Cancer	22 (7.9)	9 (9.4)	0.64

Notes: Continuous, normally distributed data were analyzed using the Student’s t-test. Non-normally distributed variables were analyzed using the Mann–Whitney U-test. Analyses of the spread of categorical variables were calculated using the Pearson chi-squared test or Fisher’s exact test where appropriate. Data were continuous variables and skew distribution, which were presented as median values.

Abbreviations: AKI, acute kidney injury; CA-AKI, community-acquired AKI; HA-AKI, hospital-acquired AKI.

Table 2 Duration of stay in CA-AKI versus HA-AKI

Variables	CA-AKI	HA-AKI	P-value
Duration of mechanical ventilation (IQR) (days)	8 (4–15)	11 (7–17)	0.020
Duration of ICU stay (IQR) (days)	9 (6–17)	11 (6–16)	0.863
Duration of hospitalization (IQR) (days)	12 (8–17)	14 (9–20)	0.038

Abbreviations: AKI, acute kidney injury; CA-AKI, community-acquired AKI; HA-AKI, hospital-acquired AKI; ICU, intensive care unit; IQR, interquartile ratio.

Figure 2 In-hospital outcomes for CA-AKI versus HA-AKI.

Notes: This graph demonstrates the percentage of AKI episodes that necessitated renal replacement therapy, ICU admission, mechanical ventilation, invasive mechanical ventilation, and non-invasive mechanical ventilation during hospitalization. This figure shows a comparison of inpatient mortality between CA-AKI and HA-AKI. The numbers at the top of the individual bars reflect the actual numbers of AKI episodes within this group. P-values were calculated using the Pearson chi-squared test/Fisher’s exact test where appropriate.
Abbreviations: AKI, acute kidney injury; CA-AKI, community-acquired AKI; HA-AKI, hospital-acquired AKI; ICU, intensive care unit.

Table 3 Cox regression survival analyses for inpatient mortality

Variables	Hazard ratio (95% CI)	P-value
Admission to ICU	1.32 (0.62–2.79)	0.47
Mechanical ventilation	0.86 (0.45–1.67)	0.67
Acute respiratory failure	3.19 (1.63–6.24)	0.001
Renal replacement therapy	2.65 (1.21–5.78)	0.015
AKI stage 3 compared with AKI stages 1 and 2	1.40 (1.02–1.92)	0.036
HA-AKI compared with CA-AKI	1.70 (1.03–2.81)	0.038

Abbreviations: AKI, acute kidney injury; CA-AKI, community-acquired AKI; CI, confidence interval; HA-AKI, hospital-acquired AKI; ICU, intensive care unit.

Figure 3 Kaplan–Meier survival curves comparing community-acquired AKI and hospital-acquired AKI groups.

Abbreviation: AKI, acute kidney injury.

Figure 4 Inpatient mortality outcomes according to AKI stage.

Notes: This figure details the percentage of patients in each AKI stage who died during hospitalization. P < 0.001 for comparison between inpatient death in AKI stage 3 (Pearson chi-squared test). For AKI stages 1 and 2, comparisons of inpatient mortality between CA-AKI and HA-AKI groups were not significant.
Abbreviations: AKI, acute kidney injury; CA-AKI, community-acquired AKI; HA-AKI, hospital-acquired AKI.