Introduction

Chronic obstructive pulmonary disease (COPD) is a common respiratory disease affecting approximately 174 million people in the UK.¹ It mainly affects patients who are older with a history of smoking. COPD carries significant morbidity and mortality as this issue can significantly affect a patient's breathing and can get worse as time goes on affecting quality of life. However early detection and management can help to prevent harm and improve patient outcomes.²

COPD is problematic as it can increase the risk of further issues, including respiratory bacterial infections, particularly pneumonia.³

In this article we will examine the connection between COPD and bacterial pneumonia. As both conditions are important and potentially dangerous with devastating consequences.

What is COPD?

COPD is an obstructive respiratory disease. It results in restricted airflow and difficulties breathing. COPD is divided into two types, chronic bronchitis and emphysema. In both cases breathing is restricted, the lungs can become inflamed and irritated and blocked by phlegm.

Chronic bronchitis- It is inflammation of the bronchi that is responsible for carrying air into the lungs.

Emphysema- It is a condition that damages and destroys the alveoli of the lungs, these are the air sacs that are involved in respiration in the lungs.^4,5

What is bacterial pneumonia?

Pneumonia is an infection of the lungs, it can affect either one or both of the lungs and can be caused by a virus, fungus or bacteria. Pneumonia causes inflammation of the lungs and causes the alveoli to become inflamed and filled with fluid. This not only affects the patient’s ability to breathe properly, but also the lack of adequate airway exchange in the lungs means a low level of oxygen within the blood. Thereby leading to further complications.⁵

Bacterial pneumonia is the most common form of this issue. It can be caused by a range of bacteria, but the most common is Streptococcus Pneumoniae. In young or healthy individuals these bacteria can remain in the throat and not cause any problems. However, in individuals who are immunocompromised or suffer from other medical conditions such as diabetes, this bacterium can enter and infect the lungs causing a bacterial infection.^5,6

What are the symptoms of bacterial pneumonia?

• Cough- This can be either a dry cough or a productive cough with yellow, green or brown coloured phlegm. Phlegm may also be blood-stained. It may be painful to cough also
• Chest pain- This can be a sharp pain that is worse on inspiration
• Fever with or without chills and sweating
• Rapid or shallow breathing
• Shortness of breath
• Muscle aches
• Fatigue- Pneumonia can make one feel very tired and lethargic with low energy

Other symptoms also include loss of appetite, nausea, vomiting and in cases of severe oxygen reduction, blue coloured nails and lips.^4,7

Risk factors for bacterial pneumonia

• Immunosuppression- A weak immune system caused by diseases such as HIV/AIDS and cancer, or treatment with immunosuppressants such as chemotherapy, steroids, or biological agents
• Co-existing medical problems- Other conditions such as diabetes, kidney disease, Parkinson’s disease, or recent surgery due to their effects on the body can increase the risk of pneumonia. Medical conditions such as stroke, epilepsy, drug abuse and anesthesia before surgery increase the risk of aspiration, which increases bacterial pneumonia risk
• Other respiratory conditions- Conditions such as TB or cystic fibrosis, can cause bacterial pneumonia as a secondary condition
• Exposure to airborne pollutants- Polluted air including household pollution from heating and cooking as well as environmental pollution can contain microorganisms that may result in the bacterial pneumonia⁷
• Smoking- This increases the risk of bacterial pneumonia. A study reports that smokers had a 42% increased risk of recurrent bacterial pneumonia in a space of a year of contracting and being hospitalized for bacterial pneumonia. This risk rises in patients who have preexisting COPD⁸

Diagnosis

Bacterial pneumonia is definitively diagnosed via a chest x-ray. This will give a visual representation of the lung and can show areas of the lung affected by the infection. Bacterial pneumonia has a characteristic picture on a chest X-ray. This is because bacterial pneumonia causes consolidation. This is a collection of fluid or pus in the airways because of the debris and dead white cells that have been sent to fight an infection. This shows up very typically as a white opaque layer on an X-ray. Whereas the non-infected areas of the lung appear as normal, indicating normal air exchange within these lung areas. Hence bacterial pneumonia can be diagnosed depending on the area being affected from chest X- ray findings, e.g. lobar pneumonia.⁹

Treatment

Treatment for bacterial pneumonia is as for any bacterial infection and is treated with antibiotics.¹⁰

Pneumonia can be treated in primary or secondary care depending on severity. In mild cases, it can be managed in a general practice setting where the patient is given a course of oral antibiotic treatment with advice on lifestyle measures such as good fluid intake, the use of paracetamol for fever,  good hygiene measures and advice on when to seek help. In more severe cases hospitalization particularly for patients with COPD, and antibiotic treatment may need to be given intravenously. In hospitals, additional measures including, monitoring heart and respiration rates, oxygen levels, and administering IV fluids can be done. As well as treatment with further medications such as bronchodilators and steroids to open up the airways and reduce lung inflammation.^4,5,10

Complications of bacterial pneumonia

• Pleurisy: When the pleural lining (the lining between the lungs and ribcage) becomes inflamed, this can be a precursor to respiratory failure
• Respiratory failure- When the lungs cannot perform air exchange, this means there is not enough oxygen in the blood leading to possible tissue death
• Lung abscesses- Where sacs of pus that form in the lung, these may need to be drained or require treatment with high doses of antibiotics
• Sepsis: When infection spreads into the blood and causes widespread infection leading to multiple organ failure^3,5

Most patients with a healthy immune system recover well from bacterial pneumonia with adequate treatment. However, patients such as those with COPD are at risk of these complications due to their condition.

How bacterial pneumonia affects people with chronic obstructive pulmonary disease (COPD)

COPD weakens the lungs and respiratory system, thereby makes the patient susceptible to bacterial pneumonia. Furthermore, as the lungs and airways are already weak and damaged along with a compromised immune system, bacterial pneumonia affects a patient more significantly than in someone without COPD.^4,5

Bacterial pneumonia affects people with COPD in a number of ways. Patients with COPD are more likely to contract COPD in the first instance, in fact, they are 16 times more likely to get bacterial pneumonia compared with the average non-COPD sufferer. If COPD patients do contract bacterial pneumonia it is usually a much more severe form with a long time to improve and the risk of morbidity and mortality is much higher. COPD sufferers also take longer to recover bacterial pneumonia and frequently require hospitalisation. This is largely because bacterial pneumonia can lead to complications, such as respiratory failure and other systems such as the heart, kidney and brain can be affected by the lack of oxygen.³ Therefore, bacterial pneumonia combined with existing COPD can significantly negatively affect patient outcomes. All of these issues mean that individuals with COPD are more likely to die of bacterial pneumonia.

Another study found that more than 35% of first-time hospitalisations for exacerbations of COPD were in patients who had also contracted pneumonia.¹² In a cohort study looking at patients over 40 with community acquired pneumonia the incidence of bacterial pneumonia was 4.42 times higher than in COPD patients without bacterial pneumonia.¹³

A cohort study of patients over 40 with community-acquired pneumonia (CAP) found that the incidence of CAP was 4.42 times higher in COPD patients than in those without CAP. Another study found that COPD patients who contract bacterial pneumonia are more likely to die and those with it have a higher 30 -90 day mortality rate.¹⁴

Preventing bacterial pneumonia with COPD

Due to the danger bacterial pneumonia can have on COPD sufferers, it is important that measures are taken to prevent this from affecting those with COPD.

Techniques to reduce the risk include:

• Good hygiene, with frequent hand washing with soap and water
• Vaccinating COPD patients against infections such as COVID-19, flu, shingles as well as pneumonia
• Smoking cessation, COPD patients usually have a history of smoking, quitting smoking will help to improve patient symptoms and prevent a patient’s further lung function decline
• Rescue packs provided by health professionals to patients preemptively containing antibiotics and steroids to use if they feel they are getting a bacterial chest infection which may become pneumonia
• Good management of COPD. This is a chronic long-term condition that needs to be managed well. Ensuring that a patient's COPD is managed well and controlled well with the medication a patient has, titrating doses and adding additional treatment as necessary helps to prevent this issue from getting worse and becoming susceptible to bacterial pneumonia and other infections⁵

Summary

Bacterial pneumonia is an infection affecting the respiratory system. In healthy patients, bacterial pneumonia can be treated effectively and patients can recover adequately. However, in patients with COPD who already have a weak respiratory and immune system, the evidence shows that this can be problematic. Therefore, it is important that COPD in a patient is well controlled, and early treatment via rescue packs and good prevention via good hygiene and vaccination against pneumonia is done to prevent harmful outcomes.