Acute Exacerbations of COPD: Delay in Presentation and the Risk of Hospitalization

Figures & data

Table 1 Demographic and baseline clinical characteristics of patients presenting to the emergency department with an acute exacerbation of chronic obstructive pulmonary disease, according to duration of symptoms

Characteristic	Symptoms < 24 h (n = 119)	Symptoms ≥ 24h (n = 277)	p-value
Demographic factors
Age, median (IQR), years	70 (62–77)	69 (62–75)	0.52
Female sex, %	43	56	0.02
Race, %			0.12
White	66	72
Black	21	21
Hispanic	12	5
Other	2	1
Body mass index, median (IQR), kg/m^2	23.8 (20.5-27.9)	25.6 (21.5-30.2)	0.02
High school graduate, %	50	56	0.29
Household income, median (IQR), $	36,698 (23,050-45,691)	38,630 (29,530-47,694)	0.07
Healthcare-related factors
Insurance status, %			0.06
Private	22	26
Medicaid	22	12
Other public	50	50
None	7	12
Has primary care provider, %	88	91	0.40
ED usual site for problem COPD care, %	63	48	0.007
ED usual site for COPD prescriptions, %	18	14	0.29
Smoking related factors
Smoking status, %			0.83
Never smoker	8	9
Current smoker	30	30
Past smoker	62	60
Pack-years of smoking, median (IQR)	53 (35–80)	51 (29–79)	0.38
Diagnosis, %			0.38
COPD only	53	57
Mixed COPD and asthma	47	42
Severity of chronic COPD
Duration of COPD history, median (IQR), years	6 (3–19)	9 (4–19)	0.24
Breathing between COPD exacerbation, %			0.18
No symptoms	18	20
Some symptoms on some days	36	26
Some symptoms on most days	19	24
Symptoms most of the time	28	31
Ever admission for COPD, %	69	64	0.33
Ever intubation for COPD, %	19	12	0.046
Ever taken corticosteroid for COPD, %	65	65	0.96
Admissions for COPD in past year, median (IQR)	0 (0–3)	0 (0–1)	0.01
Urgent clinic visits in past year, median (IQR)	0 (0–1)	0 (0–2)	0.12
Number of ED visits in past year, median (IQR)	2 (0–5)	1 (0–3)	< 0.001
COPD medications in past 4 weeks, %
Inhaled β -agonists	89	80	0.04
Inhaled anticholinergics	70	61	0.08
Inhaled corticosteroid	49	49	0.95
Systemic corticosteroid	35	37	0.72
Methylxanthine	20	16	0.39
Antibiotics	15	19	0.39
Comorbidity, %
Coronary artery disease	18	24	0.17
Congestive heart failure	13	21	0.06
History of arrhythmia	10	13	0.36
Depression	10	13	0.42

Abbreviations: COPD, chronic obstructive pulmonary disease; ED, emergency department; IQR, interquartile range.

Figure 1 Percentage of patients with acute exacerbation of chronic obstructive pulmonary disease presenting to the emergency department after varying amounts of time from symptom onset.

Table 2 Emergency department presentation, course, disposition, and relapse in patients with an acute exacerbation of chronic obstructive pulmonary disease, according to duration of symptoms

Characteristic	Symptoms < 24 h (n = 119)	Symptoms ≥ 24h (n = 277)	p-value
Symptoms and pre-ED arrival treatment
Severity of exacerbation in past 24 hrs, median (IQR)
Frequency of COPD symptoms	3 (2–3)	3 (3–4)	< 0.001
Severity of COPD symptoms^†	3 (3–4)	4 (3–4)	0.002
Activity limitations^†	3 (3–4)	4 (3–4)	0.001
Triggered by respiratory infection	37	65	< 0.001
Airway symptoms^‡
More short of breath than usual	87	92	0.37
Coughing more than usual	51	74	0.01
Bringing up more sputum	35	62	0.006
Change in sputum color	29	41	0.24
No. of β -agonist puffs within 6 hours of ED, median (IQR)	6 (2–12)	4 (0–8)	0.009
No. of anticholinergic puffs within 6 hours of ED, median (IQR)	0 (0–4.5)	0 (0–4)	0.78
ED presentation
ED triage time, %			0.02
Midnight to 7:59 AM	21	12
8:00 AM to 3:59 PM	50	64
4:00 PM to 11:59 PM	29	24
Respiratory rate, median (IQR), breaths/min	24 (22–28)	24 (20–28)	0.17
O2 saturation in room air, median (IQR), %^§	94 (89–97)	93 ([7])	0.20
Arterial blood gas, median (IQR) ^‖
pO2, mmHg	68 (56–107)	64 (54–78)	0.22
pCO2, mmHg	45 (41–56)	48 (38–61)	0.52
Concomitant diagnosis, %
Pneumonia	17	16	0.79
Congestive heart failure	10	13	0.39
Arrhythmia	0.8	4	0.09
Pneumothorax	0.8	0.0	0.13
ED course
No. of inhaled β -agonist treatments in first hour, median (IQR)^¶	1 (1–2)	1 (0–2)	0.002
No. of inhaled β -agonist treatments over ED stay, median (IQR)^¶	3 (2–4)	3 (1–3)	0.04
No. of inhaled anticholinergic treatments in first hour, median (IQR)^¶	1 (0–1)	0 (0–1)	0.08
No. of inhaled anticholinergic treatments over ED stay, median (IQR)^¶	1 (1-3)	1 (1-2)	0.35
Received systemic corticosteroids in ED, %	63	61.5	0.77
Received antibiotics in ED, %	23	30.7	0.11
Received NIPPV, %	3	3.2	0.95
Received intubation in ED, %	0.8	0.3	0.55
ED outcomes
ED length of stay, median (IQR), minutes	295 (196–415)	314 (230–484)	0.10
ED disposition, %			0.02
Sent home	46	35
Observation	0.9	2
Hospital admission	42	57
Intensive care unit admission	8	6
Others	3	0.4
Discharge medications, % **
Sent home on systemic corticosteroids	60	57	0.68
Post-ED follow-up, % ^††
Relapse event at 48 h	5	2	0.18
Relapse event at 2 wks	19	17	0.65

Abbreviations: COPD, chronic obstructive pulmonary disease; ED, emergency department; IQR, interquartile range; and NIPPV, noninvasive positive pressure ventilation.

*On 4-point ordinal scale. (1, none of the time; 2, some of the time; 3, most of the time; 4, all of the time).

†On 4-point ordinal scale. (1, none; 2, mild; 3, moderate; 4, severe).

‡Available for 122 patients.

§Available for 277 patients.

‖Available for 112 patients.

¶Each nebulizer treatment was counted as equivalent to six puffs from a metered-dose inhaler.

**Restricted to patients sent home from ED (n = 150).

††Restricted to patients available for follow-up (n = 349).

Table 3 Results from the unadjusted and multivariate logistic regression analysis for the association between duration of symptoms before presentation and risk of hospitalization among patients with acute exacerbation of chronic obstructive pulmonary disease

Duration of symptoms (sample size)	Covariates adjusted for	Odds ratio for admission (95%CI)
≥ 24 hours vs. < 24 hours (n = 396)	Unadjusted	1.63 (1.04–2.54)
≥ 24 hours vs. < 24 hours (n = 396)	Age, sex, race, ED as usual site of care, codiagnosis of asthma, number of ED visits in last 1 year, inhaled steroid use in the 4 weeks prior to presentation, history of cardiac arrhythmia, inhaled beta agonist use in the 6 hours preceding presentation, respiratory rate, oxygen saturation, and presence of pneumonia on the chest x-ray	2.30 (1.11-4.76)
≥ 12 hours vs. < 12 hours (n = 396)	Adjusted for same variables as above	2.33 (1.03–5.28)
≥ 24 hours vs. < 24 hours, excluding ICU admission (n = 365)	Adjusted for same variables as above	2.40 (1.13-05.10)
≥ 24 hours vs. < 24 hours, if ED is usual site of care (n = 203)	Adjusted for same variables as above	4.11 (1.16–14.62)

Abbreviations: ED: Emergency Department, ICU: Intensive Care Unit.

Aaron S D, Vandemheen K L, Hebert P, Dales R, Stiell I G, Ahuja J, Dickinson G, Brison R, Rowe B H, Dreyer J, Yetisir E, Cass D, Wells G. Outpatient oral prednisone after emergency treatment of chronic obstructive pulmonary disease. N Engl J Med 2003; 348: 2618–2625

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