Blood eosinophils and mortality in patients with acute respiratory distress syndrome: A propensity score matching analysis

doi:10.5847/wjem.j.1920-8642.2021.02.008

Abstract

Abstract:

BACKGROUND: The effect of blood eosinophils (EOSs) on mortality in acute respiratory distress syndrome (ARDS) patients and whether corticosteroids affect this effect are unclear.

METHODS: The Medical Information Mart for Intensive Care III database (version 1.4) was used to extract data. Patients with ARDS were selected for inclusion. Cox regression models using the backward stepwise method and propensity score matching (PSM) were used to assess the relationship between blood EOS counts and 28-day mortality.

RESULTS: A total of 2,567 patients with ARDS were included, and the 28-day mortality rate was 24.19%. The crude 28-day mortality was significantly lower in patients with EOS counts ≥2% (18.60% [85/457] vs. 25.40% [536/2,110], P=0.002) than in those with EOS counts <2%. In the Cox regression model, the EOS counts ≥2% showed a significant association with the decreased 28-day mortality (hazard ratio [HR] 0.731; 95% confidence interval [95% CI] 0.581-0.921, P=0.008). In the corticosteroid non-use subgroup, EOS counts ≥2% was significantly related to decreased 28-day mortality (HR 0.697, 95% CI 0.535-0.909, P=0.008), but the result was not significant in the corticosteroid non-use subgroup model (P=0.860). A total of 457 well-matched pairs were obtained by a 1:1 matching algorithm after PSM. The 28-day mortality remained significantly lower in the EOS counts ≥2% group (18.60% [85/457] vs. 26.70% [122/457], P=0.003).

CONCLUSIONS: Higher EOS counts are related to lower 28-day mortality in ARDS patients, and this relationship can be counteracted by using corticosteroids.

Key words: Critical care, Acute respiratory distress syndrome, Eosinophils, Mortality, Corticosteroid

Hao-tian Chen, Jian-feng Xu, Xiao-xia Huang, Ni-ya Zhou, Yong-kui Wang, Yue Mao. Blood eosinophils and mortality in patients with acute respiratory distress syndrome: A propensity score matching analysis[J]. World Journal of Emergency Medicine, 2021, 12(2): 131-136.

Figures/Tables 4

Table 1

Comparisons of baseline characteristics between survivors and non-survivors

Variables	Total (n=2,567)	Survivors (n=1,946)	Non-survivors (n=621)	P
Age (years)	63.35 (51.39-75.98)	62.14 (50.38-74.55)	68.02 (55.20-79.44)	<0.001
Male, n (%)	1,479 (57.62)	1,127 (57.91)	352 (56.68)	0.589
Weight (kg)	81.1 (68.0-97.1)	82.3 (70.0-98.2)	77.9 (64.1-92.3)	<0.001
BMI (kg/m²)	27.91 (24.13-32.91)	28.23 (24.41-33.09)	27.08 (22.79-31.98)	<0.001
Heart rate (beats per minute)	88.37 (78.89-98.47)	88.05(78.96-97.69)	89.68 (78.90-100.89)	0.028
MAP (mmHg)	77.25 (71.92-84.17)	77.79 (72.30-84.17)	75.85 (70.74-84.51)	0.073
PaO₂/FiO₂ ratio	237.83 (193.89-289.95)	239.17 (194.67-291.77)	232.50 (191.42-279.47)	<0.001
Comorbidities, n (%)
Diabetes	728 (28.36)	562 (28.88)	166 (26.73)	0.301
Sepsis	1,584 (61.71)	1,165 (59.87)	419 (67.47)	0.001
Severity of illness
SAPS II	44 (35-55)	42 (33-52)	53(44-64)	<0.001
ARDS severity, n (%)
Mild	379 (14.76)	305 (15.67)	74 (11.92)	<0.001
Moderate	1,023 (39.85)	816 (41.93)	207 (33.33)
Severe	1,165 (45.38)	825 (42.39)	340 (54.75)
Laboratory data
WBC (×10⁹/L)	12.8 (8.8-18.1)	12.5 (8.8-17.5)	14.0 (8.9-19.4)	0.003
RBC (×10⁹/L)	3.58 (3.10-4.10)	3.59 (3.11-4.11)	3.54 (3.06-4.07)	0.133
PLT (×10⁹/L)	201 (139-276)	202 (144-270)	197 (118-294)	0.056
Lactate (mmol/L)	2.1 (1.4-2.7)	2.0 (1.3-2.5)	2.5 (1.7-3.8)	<0.001
EOS counts initial (×10⁹/L)	0.2 (0-1.0)	0.3 (0-1.0)	0.1 (0-0.6)	<0.001
EOS counts minimum (×10⁹/L)	0.2 (0-0.9)	0.2 (0-1.0)	0.1 (0-0.4)	<0.001
EOS counts maximum (×10⁹/L)	0.4 (0-1.2)	0.5 (0.1-1.3)	0.2 (0-1.0)	<0.001
pH	7.35 (7.28-7.42)	7.36 (7.29-7.42)	7.33 (7.26-7.41)	<0.001
Mechanical ventilation
Tidal volume (mL/kg PBW)	6.65 (5.41-8.04)	6.56 (5.35-7.95)	6.85 (5.63-8.21)	0.001
Minute ventilation (L/min)	9.8 (8.0-12.4)	9.6 (7.9-12.0)	10.4 (8.3-13.8)	<0.001
Low tidal volume, n (%)	1,167 (45.46)	910 (46.76)	257 (41.38)	0.019
Drug usage, n (%)
Corticosteroid use	436 (16.98)	276 (14.18)	160 (25.76)	<0.001
Vasopressor use
No vasopressor	1,765 (68.76)	1,442 (74.10)	323 (52.01)	<0.001
One vasopressor	512 (19.95)	338 (17.37)	174 (28.02)
Two vasopressors	290 (11.30)	166 (8.53)	124 (19.97)
Antibiotics use	2,208 (86.01)	1,677 (86.18)	531 (85.51)	0.308

Table 1

Table 2

Figure 1.

Table 3

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Variables	Total (n=2,567)			Patients who used corticosteroids (n=436)			Patients who did not use corticosteroids (n=2,131)
Variables	EOS counts <2% (n=2,110)	EOS counts ≥2% (n=457)	P	EOS counts <2% (n=389)	EOS counts ≥2% (n=47)	P	EOS counts <2% (n=1,721)	EOS counts ≥2% (n=410)	P
28-day mortality, n (%)	536 (25.40)	85 (18.60)	0.002	139 (35.73)	21 (44.68)	0.229	397 (23.07)	64 (15.61)	0.001
ICU mortality, n (%)	448 (21.23)	71 (15.54)	0.006	125 (32.13)	22 (46.81)	0.144	323 (18.77)	49 (11.95)	0.001
Hospital mortality, n (%)	527 (24.98)	81 (17.72)	0.001	140 (35.99)	21 (44.68)	0.244	387 (22.49)	60 (14.63)	<0.001
Length of ICU stay (days)	6.17 (3.67-11.92)	6.21 (3.58-12.38)	0.918	7.29 (4.33-14.13)	7.33 (3.71-12.13)	0.538	5.96 (3.46-11.33)	6.08 (3.46-12.63)	0.629
Length of hospital stay (days)	12.00 (7.25-20.25)	11.92 (7.38-21.83)	0.340	14.17 (8.25-23.83)	12.21 (6.88-16.92)	0.094	11.75 (7.16-19.00)	11.89 (7.38-22.88)	0.392

Variables	Model 1			Model 2			Model 3
Variables	HR	95% CI	P	HR	95% CI	P	HR	95% CI	P
EOS counts	0.731	0.581-0.921	0.008	0.697	0.535-0.909	0.008	/	/	/
SAPS II	1.029	1.024-1.035	<0.001	1.032	1.026-1.038	<0.001	1.025	1.014-1.035	<0.001
Lactate	1.110	1.081-1.140	<0.001	1.111	1.077-1.147	<0.001	1.131	1.072-1.195	<0.001
Minute ventilation	1.033	1.011-1.055	0.003	1.036	1.010-1.062	0.005	/	/	/
Vasopressor use	1.288	1.159-1.431	<0.001	1.368	1.208-1.548	<0.001	/	/	/
ARDS severity	1.563	1.252-1.952	<0.001	1.787	1.497-2.134	<0.001	/	/	/
BMI	0.984	0.974-0.995	0.004	0.980	0.967-0.992	0.002	/	/	/
Age	1.002	1.001-1.004	0.003	1.002	1.001-1.004	0.003	/	/	/
PaO₂/FiO₂ ratio	0.998	0.996-0.999	0.018	/	/	/	0.991	0.988-0.993	<0.001

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