CLINICAL PRESENTATION AND
PREDICTORS OF OUTCOME IN
PATIENTS WITH SEVERE ACUTE
EXACERBATION OF COPD
REQUIRING ADMISSION TO ICU
By Mohan et al
BACKGROUND
• COPD is a common, costly preventable disease and is
the 4th leading cause of death globally
• Acute exacerbation of COPD(AE-COPD) is a common
cause of ER visit
• Major cause of morbidity and mortality with more than
half of these patients requiring re-admission in
subsequent 6 months
• Great variability in clinical course making predictions of
outcome in a given patient difficult
• The study was designed to prospectively study the
clinical presentation and predictors of outcome in
patients with AE-COPD requiring admission to ICU
METHODS
• During period from June 2000 and December 2004 ,
914 patients diagnosed with COPD in MOPD and Chest
Clinic at a Tertiary Hospital
• 314 of these later on presented to ER with AE-COPD
• After appropriate initial treatment, 116 admitted to
Medical ICU, 18 discharged, 180 admitted to Acute
Medical Unit and Medical Ward
• Basis of study is on the 116 admitted to ICU
• Patients with bronchiectasis, interstitial lung
disease,PE, Pulmonary Oedema excluded
• Study was approved by Ethical Committee
• COPD diagnosed on basis of Pulmonary Function
tests during MOPD visits
• AE-COPD diagnosed if all following present: rapid
worsening dyspnoea, increase in sputum volume
and purulence
• Only single enrolement per patient regardless of
frequency of exacerbations
• On arrival full Hx including type of smoking habit
cigarette or bidi and pack years, domestic fuel
use and examination
• Baseline investigations including imaging
• O2 given as appropriate nasal prongs, face mask or
Ventura devices
• Nebs of Salbutamol/Ipratropium every 15 min to 8 hourly ,
steroids if no improvement iv aminophylline. Empiric
antibiotics given could be changed on sensitivities
• No standard criterion for Invasive Ventilation
• In study indications include, failure to respond to
pharmacologic and other non-ventilatory Rx, severe
dyspnoea, severe acidosis (pH < 7,25) , hypercapnea (P
CO2 > 60mmHg), life threating hypoxaemia, respiratory
arrest, somnolence, impaired mental status and co-morbid
illness
STATISTICAL ANALYSIS
• Variables following normal distribution were summarised
by mean and standard deviation
• Association between two categorical variables was by χ2
or Fisher’s exact test as appropriate
• Student t test used for quantitative variables
• Quantitative variables categorised and if it showed
statistically significant association with outcome at p < 0.20
considered for inclusion
• Stepwise multivariate logistic regression performed with
potential candidate variables as co-variates
• SYSTAT Version 7.0 used. All stat tests performed were two
tailed, p <0.05 considered statistically significant
RESULTS
. Mean age 62.1 ± 9.8 years with 102(88%) males
.Mean duration of COPD 7.2 ± 5.8 years
.All males were smokers for 22.3 ± 11.2 pack years 35.2% smoked cigarettes
and 64.8 % smoked bidis. All women non-smokers and were exposed to
domestic fuels
.81 (69.8%) patients had co-morbid illness with 53 (45.7%) having one
condition and 28(54.3%) having 2 or more
.Past PTB in 33(28.4%) patients, 5 patients with Type 2 DM found to have
active PTB
.ABG showed Respiratory Failure in 40(33.8 %) patients Type 1 in 17.5% and
Type 2 in 82.5%
.Invasive Ventilation required in 18 patients
.16 (13.7%) patients died in the study
Predictors of death: need for invasive ventilation, presence of co-morbid
illness and hypercapnoea
Table 1 Demographic characteristics and co-morbid conditions in 116 patients with acute exacerbation of chronic obstructive
pulmonary disease admitted to the medical intensive care unit
Age (years) (mean ± SD)
Gender
Male
Female
Smoking (all males)
Duration of symptoms (years) (mean ± SD)
COPD, GOLD stage*
Moderate [No. (%)]
Severe [No. (%)]
Very severe [No. (%)]
Co-morbid conditions
Hypertension [No. (%)]
Alcoholism [No. (%)]
Type II diabetes mellitus [No. (%)]
Past pulmonary tuberculosis [No. (%)]
Coronary artery disease [No. (%)]
Chronic renal failure [No. (%)]
Number of co-morbid illnesses
0 [No. (%)]
1 [No. (%)]
2 [No. (%)]
3 [No. (%)]
4 [No. (%)]
•
•
•
•
•
•
•
62.1 ± 9.8
102
14
22.3 ± 11.2 pack years
7.6 ± 5.2
25 (21.6)
55 (47.4)
36 (31.0)
40 (34.5)
38 (32.8)
36 (31.0) †
33 (28.4) ‡
12 (10.3)
10 (08.6)
35 (30.2)
53 (45.7)
18 (15.5)
07 (06.0)
03 (02.6)
GOLD = Global Initiative for Chronic Obstructive Lung Disease (reference 1)
COPD = chronic obstructive pulmonary disease
* In all patients post-bronchodilator forced expiratory volume in one second (FEV1)/forced vital capacity (FVC) was ≤ 0.7. Moderately severe COPD,
FEV1 = 50 – 80% predicted; severe COPD, FEV1 = 30 – 50% predicted; very severe COPD = <30% predicted (reference 1)
† 3 patients had diabetic ketoacidosis and 5 patients had active pulmonary tuberculosis
‡ Clinical and radiographic evidence of past tuberculosis was present
More than one co-morbid conditions were present in several patients
Mohan et al. BMC Pulmonary Medicine 2006 6:27 doi:10.1186/1471-2466-6-27
Table 2 Clinical presentation in 116 patients with acute exacerbation of chronic obstructive pulmonary disease admitted to the
medical intensive care unit
Variable
Symptoms
Cough
Increased sputum volume
Increased sputum purulence
Recent rapid worsening of dyspnea
Accessory muscle use
Inability to complete a full sentence while talking
Pedal edema
Fever
Altered sensorium
Upper respiratory infection
Gastroesophageal reflux
Signs
Wheezing
Respiratory rate > 24/min
Crepitations
Cyanosis
Heart rate > 100/min
Elevated JVP
Systolic BP < 90 mm Hg
•
•
%
100
100
100
100
60.3
60.3
19.8
29.3
12.9
8.6
7.8
100
94
56
33.6
25
12.9
3.4
JVP = jugular venous pulse
Mohan et al. BMC Pulmonary Medicine 2006 6:27 doi:10.1186/1471-2466-6-27
Table 3 Laboratory abnormalities in 116 patients with acute exacerbation of chronic obstructive pulmonary disease admitted
to the medical intensive care unit
Variable
%
Polycythemia (PCV >54% in men, >49% in women)
32.8
Leukocytosis [(>12 × 103/mm3), (>12 × 109/l)]
64.7
Neutrophilia [(> 70%), (> 0.7)]
77.6
Elevated ESR (>20 mm at the end of the first hour)
64.7
Hypoalbuminemia [(< 3.5 g/dl), (< 35 g/dl)]
19.0
Hyponatremia [serum sodium < 120 meq/l, (< 120 mmol/l)]
16.4
Hypokalemia [serum potassium < 3.5 meq/l, (< 3.5 mmol/l)]
16.4
Hyperbilirubinemia [(>1.2 mg/dl), (> 20.5 μmol/l)]
6.0
Elevated transaminases [>50 IU/l]
22.4
Elevated blood urea [(>50 mg/dl), (>17.9 mmol/l)]
45.7
Elevated serum creatinine [(>1.5 mg/dl), (> 132.6 μmol/l)]
19.0
•
ESR = erythrocyte sedimentation rate
•
Mohan et al. BMC Pulmonary Medicine 2006 6:27 doi:10.1186/1471-2466-6-27
Table 4 Predictors of outcome in 116 patients with severe acute exacerbation of chronic obstructive pulmonary disease
requiring admission to the intensive care unit: univariate sensitivity analysis
Variable
•
χ2
p-value
Presence of co-morbid illness
1.673
0.0196
Altered consciousness
3.650
0.0560
Presence of tachycardia
9.605
0.0020
Peripheral edema
1.900
0.1680
Hypoalbuminemia
4.300
0.0380
Elevated transaminases
4.200
0.0350
Acidosis
10.257
0.0010
Arterial hypoxemia
4.999
0.0250
Hypercapnia
2.189
0.1390
Presence of new infiltrates on the chest radiograph
5.240
0.0170
Need for invasive ventilation
16.178
0.0001
Mohan et al. BMC Pulmonary Medicine 2006 6:27 doi:10.1186/1471-2466-6-27
Table 5 Predictors of death in 116 patients with severe acute exacerbation of chronic obstructive pulmonary disease requiring
admission to the intensive care unit: stepwise multivariate logistic regression analysis
Variable
•
Odds ratio
95% Confidence intervals
p-value
Need for invasive ventilation
45.809
607.46 to 3.009
p < 0.001
Presence of co-morbid illness
0.126
0.428 to 0.037
p < 0.01
Hypercapnia
0.114
1.324 to 0.010
p < 0.05
Mohan et al. BMC Pulmonary Medicine 2006 6:27 doi:10.1186/1471-2466-6-27
DISCUSSION
• Not much info on burden of AE-COPD in ER, its presentation and
outcome
• Significant number of patients (n=53; 45.7%) had co-morbid
conditions, and this was a predictor of death
• Accurate assessment of co-morbid conditions and institution of
specific treatments should help to reduce morbidity and mortality
• Past PTB important cause of COPD and also of AE-COPD (p<0.001)
• Ramifications in areas where PTB endemic and smoking on the rise
• High prevalence of respiratory failure in study . Invasive ventilation
associated with poor prognosis
• In conclusion, in addition to host genetic factors, smoking
behaviour, accessibility to health care and presence of co-morbid
conditions contribute to morbidity and mortality due to AE-COPD