Factors associated with hospital mortality in critically ill patients with exacerbation of COPD

Figures & data

Table 1 Differences in patients’ characteristics between the surviving and deceased patients

	All patients (n=305)	Surviving (n=248)	Deceased (n=57)	P-value
Age (years)	67.41 (±10.49)	66.64 (±10.88)	70.75 (±7.86)	<0.01a
Male gender	40.3%	37.9%	50.9%	0.07b
APACHE-II score (n=304)	17.83 (±6.75)	16.94 (±6.36)	21.65 (±7.12)	<0.01a
APACHE-III score (n=304)	60.59 (±22.71)	57.90 (±21.58)	72.26 (±23.94)	<0.01a
SAPS-2 score (n=292)	37.69 (±14.86)	35.74 (±14.11)	45.77 (±15.3)	<0.01a
Pneumonia at admission (n=225)	32%	31.7%	33.3%	0.845b
Systemic steroids (n=225)	41.9%	42.1%	41.2%	0.906b
Home O2(n=224)	20.5%	16.8%	38.5%	<0.01b
Comorbidities
Diabetes (n=274)	22.6%	23%	20.40%	0.851b
Hypertension (n=281)	52.7%	52.6%	52.90%	1.000b
Coronary artery disease (n=281)	32.7%	32.6%	33.30%	1.000b
Chronic renal failure (n=298)	5.37%	5.3%	5.60%	1.000b
Malignancy (n=298)	12.08%	11.9%	13.00%	1.000b
Arrhythmia (n=273)	16.48%	15.6%	20.40%	0.545b
Depression (n=274)	22.99%	24.0%	18.40%	0.508b
Prior admissions for COPD
To hospital (n=215)	56.3%	54.7%	63.9%	0.313b
To ICU (n=210)	16.7%	15.4%	22.9%	0.282b

Notes:

a Independent sample t-tests;

b chi-square tests. Data shown as mean (± standard deviation) or %. Data in bold indicates statistical significant difference between the groups.

Abbreviations: APACHE-II score, Acute Physiology and Chronic Health Evaluation-II score; ICU, intensive care unit.

Table 2 Differences in physiological assessments between the surviving and deceased patients

	All patients	Surviving	Deceased	P-valuea
Diastolic BP, mmHg (n=291)	74.2 (±16.08)	75.42 (±15.43)	69.23 (±17.83)	0.01
Mean BP, mmHg (n=292)	99.05 (±20.05)	100.65 (±19.19)	92.45 (±22.25)	<0.01
Systolic BP, mmHg (n=291)	147.20 (±31.55)	149.63 (±29.72)	137.21 (±38.8)	0.02
Pulse rate, bpm	107.47 (±24.64)	107.61 (±23.53)	106.89 (±28.99)	0.86
Respiratory rate, brpm (n=290)	28.84 (±9.49)	29.04 (±9.04)	28.0 (±11.16)	0.51
Temperature, °C (n=290)	36.99 (±3.84)	36.74 (±0.96)	38.02 (±8.44)	0.26
Biochemistry
Highest serum lactate, mmol/L (n=205)	2.59 (±7.43)	2.74 (±8.14)	1.89 (±1.15)	0.54
PaCO2, mmHg (n=281)	63.06 (±21.40)	61.78 (±20.62)	68.86 (±23.99)	0.03
PaO2, mmHg (n=282)	11.11 (±90.05)	105.64 (±84.34)	135.33 (±109.58)	0.71
HCO3, mmol/L (n=265)	27.86 (±11.62)	27.77 (±10.52)	28.25 (±15.38)	0.79
pH (n=266)	7.39 (±0.75)	7.4 (±0.77)	7.38 (±0.65)	0.87
Albumin, g/L (n=276)	38.94 (±10.89)	38.65 (±9.42)	40.28 (±16.00)	0.49
Bilirubin, μmol/L (n=267)	7.5 (±4.53)	7.36 (±4.1)	8.52 (±5.87)	0.20
Creatinine, μmol/L (n=275)	95.68 (±57.20)	91.69 (±47.82)	113.66 (±86.22)	0.08
Glucose, mmol/L (n=283)	11.15 (±4.5)	11.34 (±4.6)	10.32 (±3.88)	0.14
Hematocrit, % (n=280)	0.45 (±0.81)	0.43 (±0.63)	0.5672 (±1.3)	0.49
Potassium, mmol/L (n=282)	6.3 (±12.61)	5.89 (±10.85)	8.55 (±18.46)	0.32
Sodium, mmol/L (n=283)	155 (±113.40)	151.62 (±97.5)	173.5 (±166.80)	0.35
Urea, mmol/L (n=278)	10.08 (±5.76)	9.66 (±5.55)	11.99 (±6.3)	<0.01
WCC, ×10^9/L (n=276)	12.98 (±6.16)	13.69 (±5.83)	15.39 (±7.4)	0.01
Lung function test
FEV1, L (n=97)	40.35 (±17.84)	40.94 (±17.38)	36.20 (±21.21)	0.39
FVC, L	70.82 (±20.62)	71.11 (±21.32)	68.56 (±12.74)	0.70
VC, L	39.05 (±37.86)	36.64 (±38.20)	67.98 (±16.46)	<0.01
DL/VA, mL/min/mmHg/L	34.0 (±24.53)	33.27 (±24.41)	39.13 (±25.90)	0.46
DLCO, mL/min/mmHg	31.91 (±13.87)	32.17 (±13.8)	30.35 (±14.7)	0.67
AaDO2, mmHg	80.6 (±150.18)	68.18 (±131.05)	131.60 (±205.94)	0.08
FiO2, %	0.44 (±0.23)	0.422 (±0.22)	0.51 (±0.27)	0.04

Notes:

a All comparisons were analyzed using independent sample t-tests. Data shown as mean (± standard deviation). Data in bold indicates statistical significance. DL/VA, diffusing capacity divided by the alveolar volume; DLCO, diffusing capacity of carbon monoxide; AaDO₂, alveolar-arterial oxygen difference.

Abbreviations: BP, blood pressure; FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity; PaO₂, partial pressure of oxygen; PaCO₂, partial pressure of carbon dioxide; WCC, white cell counts.

Table 3 Differences in patient outcomes between the surviving and deceased patients

	All patients	Surviving	Deceased	P-value
ICU mortality	11.5%
Hospital mortality	18.7%
Hospital LOS, days	11.63 (±13.05)	12.21 (±13.65)	9.09 (±9.66)	0.10a
ICU LOS, days	4.48 (±5.96)	4.12 (±5.46)	6.04 (±7.60)	0.07a
Proportion requiring NIV (n=282)	77.3%	79.7%	66.0%	0.03b
Proportion requiring IMV (n=269)	38.7%	32.1%	66.7%	<0.01b
Length of IMV, hours (n=65)	127.18 (±179.49)	103.72 (±152.38)	173.06 (±220.03)	0.19a
Length of NIV, hours (n=158)	107.97 (±701.58)	106.36 (±755.80)	117.42 (±181.99)	0.88a

Notes:

a Independent sample t-tests;

b chi-square tests. Data shown as mean (± standard deviation) or %. Data in bold indicates statistical significant difference between the groups.

Abbreviations: ICU, intensive care unit; IMV, invasive mechanical ventilation; LOS, length of stay; NIV, non-invasive ventilation.

Table 4 Significant factors associated with in-hospital mortality examined using multiple logistic regression

	OR	95% CI	P-value
Age	1.06	1.03–1.10	<0.01
Hospital LOS	0.79	0.63–1.00	<0.01
ICU LOS	1.26	1.02–1.57	<0.01
APACHE-II score	1.07	1.01–1.12	0.02
IMV requirement	4.09	1.79–9.32	0.02

Note: Data in bold indicates statistical significant difference between the groups.

Abbreviations: APACHE-II score, Acute Physiology and Chronic Health Evaluation-II score; ICU, intensive care unit; LOS, length of stay; IMV, invasive mechanical ventilation.