A Comparative Study of Bacteriological Profile and Outcomes in Infective Exacerbation of Chronic Obstructive Pulmonary Disease and Bronchial Asthma

Abstract

Background: 

According to the Global Burden of Disease 2018, chronic obstructive pulmonary disease (COPD) is the third leading cause of death worldwide, and in India, COPD is the second leading cause of death among noncommunicable diseases. Among India’s 1.31 billion people, about 6% of children and 2% of adults have bronchial asthma. Infective exacerbations of both COPD and Bronchial asthma are common. However, there are some differences in the bacterial spectra between the two conditions, and profiling the bacteria responsible for the exacerbations will help in choosing appropriate antibiotics and also to combat the issue of drug resistance.

Aims: 

(1) To analyze the bacteriological profile of patients with infective exacerbation of COPD and bronchial asthma. (2) To study the outcomes among these patients.

Subjects and Methods: 

The study was a prospective observational study conducted from November 2019 to May 2020 in Bangalore Medical College and Research Institute on 50 patients diagnosed with acute exacerbation of COPD and 50 patients diagnosed with an exacerbation of bronchial asthma. Detailed history, physical examination, and standard laboratory tests were done on admission. Sputum samples were collected from the patients and analyzed by Gram staining and microscopy and also by culture. The differences between the two groups were analyzed. The progression of the disease and the outcomes were observed.

Results: 

100 patients were included in our study, 50 each in COPD and bronchial asthma. The study was conducted in hospitals attached to BMCRI. Bacteriological profile was assessed by sputum culture and antibiotic sensitivity in the COPD and asthma groups, respectively. In our study, in the COPD group, majority (80%) of patients were males, the mean age was 64.34 ± 9.876, and 80% were smokers with 20% having exposure to biomass. The most common growth in COPD exacerbation was Streptococcus pneumoniae (18%) followed by Haemophilus influenzae and Klebsiella pneumoniae. Mortality in COPD exacerbation was 12%. In the asthma group, female preponderance was seen (54%), mean age was 40.64 ± 13.11. Majority of patients were cases of childhood asthma. Growth was seen in 32% of exacerbations and the most common organism was Streptococcus pneumoniae. Mortality was 4% and importantly due to comorbidities.

Conclusions: 

Bacterial exacerbations are more common in COPD, while it is not so in bronchial asthma. Viral exacerbations and atypical bacterial exacerbations are more common and asthma associated with pneumonia is the cause for culture growth. Mortality is considerably low in the asthma group compared to COPD exacerbations.

INTRODUCTION

According to the Global Burden of Disease (GBD) 2018, chronic obstructive pulmonary disease (COPD) is currently the third leading cause of death worldwide. The India GBD Collaborators in October 2018 showed that COPD and asthma make the second largest contribution to the total mortality burden of India at 10.9%.^[1]

Asthma is a clinical syndrome manifesting by airflow obstruction that varies markedly, spontaneously as well as by treatment. Motoyasu et al. in 2015 in Japan studied about infective exacerbation of bronchial asthma in 50 stable inpatients and 20 outpatients. They found that viruses were detected in 50% of stable outpatients, but a higher incidence of rhinovirus, respiratory syncytial virus, and metapneumovirus infections was observed in asthma exacerbation inpatients. H. influenzae was observed in stable asthmatic patients. Other bacteria, especially S. pneumoniae, were important in asthma exacerbation inpatients.^[2] Generally, viral infections are common in acute exacerbation of bronchial asthma; hence the use of antibiotics is routinely not recommended. Therefore, antibiotic use in bronchial asthma should be reserved for patients with evidence of pneumonia or sinusitis.

Thus far, the exact pathogenesis of COPD exacerbation has not been determined, but most scholars believe lower respiratory tract infections play a major role. Exacerbations pose a considerable economic burden but more importantly repeated exacerbations of COPD lead to deteriorating health-related quality of life and, when associated with ventilatory failure, to premature death.^[3]

Bronchoscopic sampling of the distal airways of the lung has demonstrated the presence of pathogenic bacteria in 50% of COPD exacerbations. Acquisition of new strains of bacterial pathogens has been associated with a more than two-fold increase in the risk of exacerbation.^[4] Bacterial exacerbations are associated with increased numbers of activated neutrophils in sputum and increased frequency of exacerbations^[5] that decline with the use of antibiotics. Because of chronic colonization, it is difficult to incriminate one of these organisms as a specific cause of an acute infection. But predominant growth of one organism, its correlation with Gram staining, its association with a change or worsening of symptoms in previously stable COPD patients, and the acute elevation of inflammatory markers can resolve this dispute.

Chawla et al., in 2008, studied 75 patients (53 treated as inpatients and 22 as outpatients) with an exacerbation of COPD. They found that Pseudomonas aeruginosa (25.92%) was the predominant organism in hospitalized patients, whereas Klebsiella pneumoniae (33.33%) was the most common pathogen isolated from outpatients. Haemophilus influenzae was not isolated.^[6]

A study was conducted by Khadanga et al. in northeastern India about the changing bacteriological profile and mortality trends in COPD. Streptococcus pneumoniae was the most common organism followed by Pseudomonas aeruginosa followed by Klebsiella pneumoniae and next was Staphylococcus aureus.^[7]

SUBJECTS AND METHODS

Study design

This was a prospective observational cross-sectional study.

Study period

The study period was November 2019 to May 2020.

Place of study

This study was conducted in Bangalore Medical College and Research Institute and hospitals attached to it.

Sample size

The sample size was 100 patients (50 in each group).

Sample size estimation

Formula:

• P1: Probability of variable in sample-1 (Value <1.0) = 0.42
• P2: Probability of variable in sample-2 (Value <1.0) = 0.09
• P: Arithmetic average of P1 and P2 = 0.255
• AH: Alternate hypothesis ONE sided (1), or TWO sided? (2) = 2
• 1−a: Set level of confidence (value <1.0). Usual values 0.95; 0.99 = 0.99
• 1−b: Set level of power of test (value <1.0). Usual values 0.8; 0.9 = 0.9
• Z1: Z value associated with set level of alpha (One sided) = 2.575829
• Z2: Z value associated with set level of beta = 1.281552
• Sample size (n) = 50 in each group.

Inclusion criteria

1. Patients who are above 18 years of either gender
2. Patient or the relatives who are willing to give informed consent
3. Patients diagnosed with COPD as per case definition [Annexure 1]
4. Patients who are diagnosed with bronchial asthma as per case definition [Annexure 1].

Exclusion criteria

1. Patients or relatives who have not given informed consent
2. Patients who are started on antibiotic for treatment of exacerbations
3. Patients with bronchiectasis, tuberculosis, malignancy, or any evidence of other conditions in chest X-ray.

Methodology

The prospective observational study was undertaken from November 2018 to May 2020 in the General Medicine Department of Bangalore Medical College and Research Institute and hospitals attached to it. After obtaining approval and clearance from the institutional ethics committee, the patients fulfilling the inclusion criteria were enrolled for the study after obtaining informed consent. The following data was collected:

• Case record form with follow up chart
• Study groups were the inpatients with acute exacerbation of COPD and Bronchial asthma admitted in Bangalore Medical College and Research Institute and hospitals attached to it
• Sputum culture and sensitivity were done in these patients, and data were collected and assessed.

The sputum isolates were also tested for antibiotic sensitivity. The differences between the two groups were analyzed. The progression of the disease and the outcomes were observed.

Assessment tools [Annexure 1]

Definition and criteria for chronic obstructive pulmonary disease and bronchial asthma

National Asthma Education and Prevention Program:

1. Episodic symptoms of airflow obstruction are present
2. Airflow obstruction or symptoms are at least partially reversible
3. Exclusion of alternative diagnoses
4. Spirometry with postbronchodilator response should be obtained as the primary test to establish the asthma diagnosis.

Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria Classification of severity of airflow limitation in COPD: In pulmonary function testing, a postbronchodilator FEV1/FVC ratio of <0.70 is commonly considered diagnostic for COPD.

• The GOLD system categorizes airflow limitation into stages. In patients with FEV1/FVC <0.70:

1. GOLD 1-mild: FEV1 ≥80% predicted
2. GOLD 2-moderate: 50% ≤FEV1 <80% predicted
3. GOLD 3-severe: 30% ≤FEV1 <50% predicted
4. GOLD 4-very severe: FEV1 <30% predicted.

Outcome measures

Assessment tools

• Sputum culturing in patients with acute exacerbation of COPD and bronchial asthma was done, and antibiotics sensitivity of the cultured organisms was assessed.

Efficacy parameters (clinical outcome parameters)

1. Mortality rates out of the patients studied the percentage of deaths during the period of hospitalization
2. Ventilator requirements-percentage of patients that developed respiratory failure necessitating ventilator requirement
3. Number of days of hospital stay
4. Number of patients requiring intensive care unit (ICU) admission.

Statistical analysis

(Statistical Package for Social Sciences) version 20. [IBM SPSS statistics (IBM corp. Armonk, NY, USA released 2011)] was used to perform the statistical analysis.

• Data was entered in the excel spreadsheet
• Descriptive statistics of the explanatory and outcome variables were calculated by mean, standard deviation for quantitative variables, frequency, and proportions for qualitative variables
• Inferential statistics like
• Chi-square test was applied for qualitative variables
• Unpaired t-test was applied to compare the quantitative variables between the COPD and asthma groups
• The level of significance was set at 5%.

RESULTS

Results and analysis

The mean age was higher for COPD subjects 64.34 ± 9.876 years as compared to asthma subjects 40.64 ± 13.11 years. Unpaired t-test was applied to compare the age between the groups. Unpaired t-test showed a statistically significant difference between the groups (P = 0.00) [Table 1 and Figure 1].

Table 1: Comparison of age between the groups using unpaired t-test

Figure 1: Bar diagram of age distribution

Out of the total 100 subjects, 26 (26%) belonged to the age group of 56–65 years followed by 21 (21%) subjects in group each of 36–45 years and above 65 years. Chi-square test was applied to associate the age with groups. Chi-square test showed statistically significant association with age (P = 0.00) [Table 2 and Figure 2].

Table 2: Age-wise distribution of the subjects

Figure 2: Bar diagram of age wise distribution of subjects

In our study, 37 out of 100 subjects (37%) were females and 63 (63%) were males. Chi-square test was applied to associate the gender with groups. Chi-square test showed statistically significant association with gender (P = 0.00) [Table 3 and Figure 3].

Table 3: Gender-wise distribution of the subjects

Figure 3: Gender wise distribution of the subjects

The mean no of years was higher for asthma subjects 26.02 ± 10.362 years as compared to COPD subjects 7.94 ± 6.86 years. Unpaired t-test was applied to compare the number of years between the groups. Unpaired t-test showed a statistically significant difference between the groups (P = 0.00) [Table 4 and Figure 4].

Table 4: Comparison of duration of illness in years between the groups using unpaired t-test

Figure 4: Comparison of number of years between the groups

Out of 100 (100%) subjects, 80 (80%) subjects had no history of previous admissions. Nine (9%) subjects had history of admissions twice. Chi-square test was applied to associate the previous admissions with groups. Chi-square test showed statistically significant association with previous admissions (P = 0.021) [Table 5].

Table 5: Distribution of the subjects based on previous admissions

Diabetes mellitus was present in 25 (25%) subjects, hypertension in 21 (21%) subjects, ischemic heart disease in 3 (3%) subjects, and past history of tuberculosis in 7 (7%) subjects. Forty-nine (49%) subjects were smokers and 16 (16%) were exposed to biomass fuel. Chi-square test was applied to associate the comorbidities and habits with groups. Chi-square test showed a statistically significant association with respect to past history of Tuberculosis (P = 0.006) and smoking habit (P = 00) [Table 6].

Table 6: Distribution of the subjects based on co-morbidities and habits

Mean years of biomass consumption was higher for COPD subjects 34.78 ± 8.693 as compared to asthma subjects 22.2 ± 12.14. Unpaired t-test was applied to compare the years of biomass consumption between the groups. Unpaired t-test showed a statistically significant difference between the groups (P = 0.00) [Table 7 and Figure 5].

Table 7: Comparison of years of biomass consumption between the groups using unpaired t-test

Figure 5: Comparison of years of biomass consumption between the groups

The mean total leukocyte count was higher for COPD subjects 12641.4 ± 4212.5 as compared to asthma subjects 12797.4 ± 8704.3. Mean neutrophils was higher for COPD subjects-80.7 ± 8.22 as compared to asthma subjects-70.19 ± 7.99. Unpaired t-test was applied to compare the total leukocyte count and neutrophils between the groups. Unpaired t-test showed a statistically significant difference between the groups (P = 0.00) with respect to neutrophils [Table 8].

Table 8: Comparison of total count and neutrophils between the groups using unpaired t-test

Consolidation was present in 29 (29%) subjects, Emphysema in 29 (29%) subjects. Chi-square test showed statistically significant association with respect to emphysema (P = 0.00) [Table 9].

Table 9: Cross-tabulation of consolidation, emphysema among the groups

Out of 50 subjects in each group, COPD showed 76% growth and asthma showed 32% growth. Chi-square test was applied to associate the growth with groups. Chi-square test showed a statistically significant association with respect to growth (P = 0.00) [Table 10 and Figure 6].

Table 10: Distribution of the subjects based on growth

Figure 6: Bar diagram showing distribution based on growth of organism

Gram-negative cocci were present in 33 (33%) subjects, Gram-positive cocci in 21 (21%) subjects. Chi-square test was applied to associate the Gram stain organisms with groups. Chi-square test showed a statistically significant association with Gram stain organisms (P = 0.00) [Table 11 and Figure 7].

Table 11: Distribution of the subjects based on gram stain

Figure 7: Bar diagram based on Gram stain

Table 12 shows the distribution based of micro-organisms. Statistically significant association was seen for coagulase-negative staphylococci (P = 0.07) and Haemophilus influenzae (P = 0.046) whereas there was no significant association seen with respect to other micro-organisms-Escherichia coli (P = 0.55), streptococcus pneumoniae (P = 0.24), Klebsiella pneumoniae (P = 0.21), Pseudomonas (P = 0.46), other organisms (P = 0.29) [Table 12].

Table 12: Distribution of the subjects based on micro-organisms

Table 13 shows the distribution based on antibiotics. Statistically significant association was seen for penicillin, cephalosporin, carbapenems, macrolides, quinolones, aminoglycosides, tetracyclines, vancomycin, and linezolid [Table 13].

Table 13: Distribution of the subjects based on commonly used antibiotics and sensitivity pattern

The mean no of days in hospital was higher for COPD subjects 11.22 ± 4.66 as compared to asthma subjects 7.82 ± 4.251. Unpaired t-test was applied to compare the no of days in hospital between the groups. Unpaired t-test showed a statistically significant difference between the groups (P = 0.00) [Table 14 and Figure 8].

Table 14: Comparison of number of days admission in hospital between the groups using unpaired t-test

Figure 8: Bar diagram no of days of stay in hospital

Out of 100 (100%) subjects, 15 (15%) had ICU admission. Chi-square test was applied to associate the ICU admission with groups. Chi-square test showed statistically significant association with ICU admission (P = 0.012) [Table 15 and Figure 9].

Table 15: Distribution of the subjects based on intensive care unit admission

Figure 9: Bar diagram on distribution of subjects based on intensive care unit admission

92 out of 100 subjects (92%) were discharged. Chi-square test was applied to associate the discharge with groups. Chi-square test showed no statistically significant association with respect to discharge (P = 0.14) [Table 16 and Figure 10].

Table 16: Distribution of the subjects based on discharge

Figure 10: Bar diagram of distribution of subjects based on discharges

Out of 100 (100%) subjects, 8 (8%) patients died. Chi-square test was applied to associate the death with groups. Chi-square test showed no statistically significant association with respect to death (P = 0.14) [Table 17 and Figure 11].

Table 17: Distribution of the subjects based on death

Figure 11: Distribution of subjects based on death

DISCUSSION

A comparative study of 100 patients with 50 each in the COPD and bronchial asthma groups, comparing the bacteriological profile and its outcomes in infective exacerbation was done in Victoria and Bowring and Lady Curzon Hospital attached to BMCRI.

In our study, the mean age in COPD patients was 64.34 ± 9.876 years which was higher compared to bronchial asthma patients, which was 40.64 ± 13.11 years. Among COPD patients, those in the 65-year age group were more in number and constituted 40% of the study group, while in the asthma group, it was the 36–45-year age group which constituted 36%. In a study conducted by Eller et al. about infective exacerbation of chronic bronchitis, 46% of patients with COPD belonged to the age group of more than 65 years.^[8] In a study conducted by Stolbrink et al. on antibiotic choice and duration associated with repeated prescriptions in infective asthma exacerbations, the maximum patients under study were <49-year-old.^[9]

In our study majority of patients in the COPD group were males (80%), while in bronchial asthma, males constituted only 46%. In a study conducted by Eller et al. about infective exacerbation of chronic bronchitis, 71% of patients with COPD were males and 29% were females.^[8]

In our study, most of the patients (about 80%) in the COPD group were smokers, while only 18% were smokers in the asthma group as well as exposure to biomass was maximum in the COPD group. In our study, consolidation was present in chest X-ray suggestive of pneumonia in 26% of patients with COPD and 29% of patients with bronchial asthma in infective exacerbation. While chest X-ray showed emphysematous changes in about 60% of patients with COPD and none of the cases in bronchial asthma.

Our study had shown total number of sputum culture-positive growth in about 38 patients out of 50 in the COPD group while the bronchial asthma group showed only growth in 16 patients out of 50 patients in acute infective exacerbation. To consider it as acute infective exacerbation we had considered history of fever, change in quantity of sputum and color of sputum as well as total WBC count and chest X-ray suggestive of opacities.

In our study growth of organisms was mostly Gram-negative bacilli in the COPD group and was about 44% (i.e., 22/50), while Gram-positive cocci were in 32% (i.e., 16), but there was Candida growth in 2 patients. However, in patients with asthma, Gram-negative bacilli growth was seen in 11 patients accounting for 22% and 5 had Gram-positive cocci accounting to 10% of infective exacerbation. There was no bacteriological growth in 12 COPD patients and 34 patients in bronchial asthma in infective exacerbation. Viral infections are the more common infections which cause exacerbation in bronchial asthma and usually no growth will be seen in such exacerbations and one more cause for exacerbation is atypical organisms such as Chlamydia, Mycoplasma, and Legionella.

In COPD patients, the most common growth was that of Gram-negative bacilli, but the most common organism grown was Streptococcus pneumoniae, which was grown in almost 9 individuals with infective exacerbation and it was sensitive to most of the common antibiotics used in regular practice. Out of patients with S. pneumoniae, one patient was admitted in ICU and was discharged after 10 days. All the patients recovered satisfactorily from the hospital and there were no deaths. Following S. pneumoniae, the next most common organism grown was Haemophilus influenzae and Klebsiella pneumoniae grown in 8 patients each. Haemophilus influenzae-infected patients were mostly resistant to penicillin in our study but were sensitive to cephalosporins and other commonly used antibiotics. The average days of stay in hospital was about 10 days and no mortality was seen in this group of patients. In Klebsiella-infected individuals, 7 out of 8 recovered and 1 individual succumbed to the infection. The patient who died had a prolonged ICU stay and multiple comorbidities. In this patient, Klebsiella was sensitive to almost all commonly used antibiotics except penicillin and macrolides.

Five patients had grown Pseudomonas aeruginosa. Out of which 3 patients were admitted in ICU. Most Pseudomonas growth was sensitive to carbapenems, cefepime, ceftazidime, tigecycline, and piperacillin-tazobactam. Two individuals were resistant to piperacillin-tazobactam. In 1 individual, the organism isolated was sensitive only to tigecycline, aminoglycosides, and daptomycin.

Three cases of coagulase-negative staphylococci growth were present, out of which 2 patients were admitted to ICU and both succumbed to illness. CONS growth in both the ICU admitted individuals were sensitive only to tigecycline, linezolid, and daptomycin.

Two patients had a moderate growth of Candida, both of them were above 70 years of age and were diabetics with poor control of glycemic status. Both had improved well and were discharged from the hospital. MRSA, Enterobacter, and Citrobacter freundii were grown in 1 patient each. Patient with MRSA growth was 66 years old and known case of COPD for 10 years with 5 past admissions with total count of 16000 at the time of admission with 90% neutrophils and chest X-ray showed opacity. The patient was admitted to the ICU for 21 days, and the antibiotic sensitivity report showed resistance to all commonly used antibiotics except tigecycline.

A 60-year-old female with diabetes and significant exposure to biomass fuel was admitted to the ICU. Her total counts were 22,000 with neutrophils of 90% and X ray revealed consolidation. Citrobacter freundii was isolated from her sputum which was resistant to all commonly used antibiotics and was sensitive to only colistin.

Another patient with Enterobacter growth was 70-year-old male patient known diabetic and hypertensive, past h/o TB, past history of admission to hospital twice with neutrophil count of 84% with AKI at the time of admission and chest X-ray showed consolidation, the patient was admitted in the hospital about 15 days in ICU. The organism was sensitive to meropenem, linezolid, and tigecycline. However, the patient succumbed to illness on 16^th day.

Six patients succumbed to the current infective exacerbation in the COPD group all of them aged above 60 years. With 4 of them having past history of admission to hospital for exacerbation, all of these patients had one or more comorbidities, elevated neutrophil counts at the time of admission, with 3 of them showing consolidation in X-ray and with prolonged hospital stay requiring admission to ICU. Rest 44 patients were discharged from the hospital.

In a study conducted by Boixeda et al. on pneumonia as a comorbidity in COPD, which was published in 2014, they had concluded that S. pneumoniae was the most common organism grown in pneumonia in COPD patients. They also found that Haemophilus influenzae and Pseudomonas were the most common organisms resulting in exacerbation of COPD. They could also conclude that there is no major difference between pneumonia in COPD and acute exacerbation of COPD in morbidity and mortality in patients with COPD.^[10]

In 2014, Tristan et al. conducted a study in the United Kingdom and found that adults with acute respiratory illness rarely have detectable bacteria in the absence of COPD or pneumonia. This was one of the largest hospital-based microbial studies conducted in hospitalized patients. They had conducted viral detection as well. But atypical bacterial detection was not done. They concluded that viral infections are more common in patients with bronchial asthma and acute bronchitis and had concluded that bacteria are found uncommonly in patients with bronchial asthma and acute bronchitis. But bacteria were found commonly in acute exacerbation of COPD and pneumonia. The most commonly grown bacterium was Streptococcus pneumoniae and was detected in 53% of patients grown for bacteria. They also inferred that antibiotics should be used in severe exacerbation of COPD, but in mild to moderate disease, antibiotic usage is still controversial and doesn’t have proven benefit.^[11] This result is consistent with our study which has shown predominant growth of Streptococcus pneumoniae followed by Haemophilus influenzae and Klebsiella pneumoniae.

Bronchial asthma patients considered in our study were 50, out of which 16 of them had shown culture positive in sputum. 11 patients had Gram-negative bacilli isolated from sputum, accounting for 22% of total positivity and 5 g positive cocci accounting for 10% of total positivity in the bronchial asthma group. All the patients with Streptococcus pneumoniae had history of fever with cough and purulent expectoration; they also had elevated white blood cell count more than 11000 with predominant neutrophilia; chest X-ray showed consolidation 4 of them suggestive of pneumonia. Patients were discharged with considerable improvement without any sequelae. All the patients were middle-aged individuals between the age group of 40 and 50 years.

Klebsiellapneumoniae was the second most common organism grown in 4 individuals. One patient 22 years old was admitted in ICU and was in ICU for 25 days; he was newly detected IgA nephropathy with secondary hypertension with chronic kidney disease on HD; total count at the time of admission was 14,000 with neutrophil of 85% and was in increasing trend; chest X-ray had shown consolidation as well as cardiomegaly. The organism was resistant to all the antibiotics including tigecycline and colistin. The patient died due to the infection with sepsis. The remaining three patients whose sputum grew Klebsiella pneumoniae were sensitive to meropenem, imipenem, tigecycline and colistin. They were treated with meropenem and improved clinically. One more patient sensitivity pattern had shown sensitivity to Piperacillin tazobactam as well and was treated with piperacillin-tazobactam.

Pseudomonas aeruginosa was the next organism grown. It was seen in 3 patients. 1 of the patient was 38-year-old known smoker and alcoholic, but with no other comorbidities, his total count was 20000 with predominant neutrophils and chest X-ray showed consolidation and the strain was sensitive to Piperacillin-tazobactam, meropenem, cefepime, ceftazidime, tigecycline. Another was a 63-year-old female patient known diabetic and ihd with bronchial asthma and was admitted for about 14 days, organism was resistant to piptaz and cephalosporins, but was sensitive to meropenem, tigecycline, daptomycin, and colistin.

Haemophilus influenzae and E. coli was grown in 2 each patients in sputum culture sensitivity. Both patients with Haemophilus growth were clinically stable and X-ray showed opacity, both had neutrophilia and sensitivity pattern showed susceptibility to most commonly used antibiotics. One of the patients with E. coli growth was 29 year old newly detected RVD, organism was susceptible to most commonly used antibiotics and was treated for 10 days and patient was discharged after initiating treatment for RVD.

One patient 65-year-old female had growth of Acinetobacter baumannii in sputum and which was resistant to most antibiotics except tigecycline and daptomycin. The patient was known diabetic and hypertensive and IHD. The patient had consolidation in X-ray and succumbed to the illness after about 25 days of hospital stay in ICU.

Almost 34 patients had shown no bacteriological growth in infective exacerbation and those exacerbations could be due to viral infections and atypical bacteria like Mycoplasma pneumoniae, Chlamydia, and Moraxella catarrhalis, which is difficult to grow in culture and requires specific tests for its detection.

A study was conducted by Iikura et al. in 2015 about the importance of bacterial and viral infections in patients with adult asthma exacerbations. There were about 50 inpatients and 20 outpatients. The most common exacerbation was due to viruses and common viruses were rhinovirus, respiratory syncytial virus, influenza virus, and metapneumovirus. The most common bacteria grown is Streptococcus pneumoniae and Haemophilus influenzae in acute exacerbation of asthma. Most of the patients with viral and bacterial exacerbation had stable asthma.^[2]

A study conducted by Papadopoulos et al. was published in 2011 on virus and bacterial cause in exacerbation of asthma which concludes that the virus is the most common cause for acute exacerbation of asthma. The most common viruses are rhinoviruses, enteroviruses, coronaviruses, influenza viruses, metapneumoviruses, parainfluenza viruses, respiratory syncytial virus, adenovirus, and human bocavirus. Atypical bacteria grown showed growth of Mycoplasma pneumoniae and Chlamydia pneumoniae. A very few showed growth of Streptococcus pneumoniae and Haemophilus influenzae. Hence antibiotics usage should be restricted to patients with pneumonia in asthma and bacterial exacerbation in asthma.^[12]

CONCLUSIONS

From our study, we were able to conclude that COPD is associated with higher proportion of bacterial exacerbation and accounted for 76% of acute infective exacerbation even though atypical bacteria was not assessed in our study, but asthma patients with acute exacerbation had bacteriological growth in only 32% of the subjects. Most asthmatic patients on inhaled corticosteroid had chest x-ray consolidation suggesting an increased chance of pneumonia in such individuals. Streptococcus pneumoniae was the most common organism resulting in bacterial exacerbation in COPD and bronchial asthma patients. Other common organisms usually grown in COPD were Haemophilus, Klebsiella, and Pseudomonas. Morbidity and mortality associated with COPD exacerbation were associated with age of the patient, comorbidities like diabetes mellitus, no of exacerbations in the past, no of days of stay in the ICU/hospital, organisms grown Pseudomonas had higher ICU admission and mortality comparatively, antibiotic sensitivity-resistance to commonly used organisms resulted in more morbidity and mortality. The morbidity and mortality associated with asthma was found to be low and depended largely upon other associated comorbidities, organism grown and its antibiotic susceptibility.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.