Respiratory System Infections

The common cold

Several different viruses, (the rhinoviruses)                                   Shift and drift

Virus damages epithelial cells causing inflammation                   Watery discharge

Condition abates in a few days as cellular immunity develops

May lead to secondary bacterial infection, eg. Staphylococci, Streptococci or Pneumococci.

 

Tonsillitis, pharyngitis, laryngitis, tracheitis, otitis media.

Remember the respiratory tract is continuous without boundaries.

Inflammation of the lining epithelium, often with pus.

 

Acute Bronchitis

Bronchitis is inflammation of the lining of the bronchi due to infection

This may lead to bronchopneumonia

 

Pneumonia

An acute inflammatory process of the substance of  lung tissue

An infection, involving the bronchial passages and the alveoli

Consolidation of the alveolar spaces with inflammatory exudates

Any lung condition in which the alveoli become filled with fluid or blood cells

Pulmonary ventilation and diffusion are impaired  -----  hypoxia

Two forms occur broncho and lobar pneumonia

Often classified by the causative organism eg pneumococcal or streptococcal pneumonia

 

Bronchopneumonia

pus in many of the bronchi in both lungs,

many small areas of infection and inflammation, possible patchy consolidation

often more marked at the bases

many kinds of bacteria

mostly infants and old people

after viral infections, aspiration or immobility

 

Often starts as a virus, especially in the young and old.

Increased risk in immobility, pre-existing reduced ventilatory function, excessive mucus production, and suppressed cough reflex.

Common aetiological organisms include, Staphylococci, Streptococci, and Pneumococci, viruses and fungi.

May also be caused by aspiration.

May be caused by immobility, referred to as hypostatic pneumonia.

A common finding after death.

A common condition, often complicates other conditions.

With Staphylococcal infection abscess formation may occur, possibly leading to metastatic infection.

 

Signs and symptoms

sudden onset of chill followed by fever, usually high 39.5`C

dyspnoea

increased respiratory rate, often shallow

respiratory rate rises out of proportion to temperature                             increased pulse rate

cough - often unproductive initially and very productive later                   crepitations

pallor                                                                                                               malaise

cyanosis in severe hypoxaemia

colour and consistency of sputum will vary with causative organism, usually tenacious, blood streaked and purulent sputum                                                                     weakness

headache and aching pains                                                                        cold sores around the mouth

 

Aetiology

Streptococcus pneumoniae (Pneumococcus)      Mycoplasma pneumoniae

Influenza A virus                                                         Haemophilus influenza

Chlamydia pneumoniae                                           Staphylococcus aureus

Pneumocystis carinii

 

Prevention

Vaccination of children against measles and pertussis

Pneumococcal vaccine may be used in "high risk" individuals

more common in:

 

Bronchial obstruction            Aspiration in oesophageal obstruction       Bulbar palsy              

Cystic fibrosis                        "Ill" patients                                                    Immunosuppression

Intravenous drug abuse        Chronic bronchitis                                         Malnutrition   

Alcoholism                             Smoking                                                         Cold weather

Overcrowding                        Hot dry indoor air                                          Air pollution

 

Nursing prevention

Mobilise                                                         nurse upright                                     

allow free chest movement                          fluids, prevent dehydration

deep breathing                                              expectoration, coughing

no smoking                                                    physiotherapy

suction if unconscious                                  antibiotics in immunosuppressed individuals

 

Observations in pneumonia

TPR BP                                                                      Tachycardia may indicate increasing hypoxia

Progress or resolution of the condition                   Possible spread of the infection and shock

Listen to breathing sounds                                       Observe for symmetrical chest movements

Listen for areas of reduced or absent air entry                  Colour - pallor, cyanosis

Type and volume of sputum - culture and sensitivity         Fluid balance chart

Disorientation or reduced levels of consciousness          Blood tests eg white cell count and ESR

CXR to identify affected areas of lung

 

Management

Aim

Resolution of consolidation ie, reabsorption and expectoration of fluids.          Kill infectious agents.

 

Prevention of spread

Droplet infections/disposal of infected sputum

Possible barrier nursing, (pneumonic plague Yersinia pestis)

 

Treat the infection

Broad spectrum antibiotics - as soon as a sputum is taken for C and S

 

Mobilisation of secretions

A mucus plug may lead to atelectasis                    Nurse propped up

Mobilisation of secretions                                        Humidified oxygen as required

Frequent positional changes                                   Patients should cough at least every hour

Physiotherapy

 

Improvement of overall condition

Physical and mental rest                              Nutrition - concentrates if necessary

Reassurance                                                 Involve family in care

Fluids 3 - 4 litres per day                              Comfort changes of gown/washes due to sweating

 

Patient comfort

Initial painful unproductive cough - linctus   Later productive cough - expectorant

Mouth care                                                                 Prevent harm during disorientation

 

Drug treatment

Mild

Amoxycillin                 Erythromycin              Amoxycillin and Erythromycin

Flucloxacillin              Oral cefaclor 250 mg 8 hourly and erythromycin 500 mg three times per day

Severe

Intravenous cefuroxime 1.5 g six hourly and erythromycin

 

Convalescence

Gradually increase activity with recovery                Extra rest for some weeks or even months

Patients may have lowered resistance for some time

Nutrition                                                                      Breathing exercises for a few weeks

 

Lobar pneumonia

Aetiology

Pneumococcus, (Streptococcus pneumoniae) almost always

Lobar pneumonia killed thousands of young adults pre penicillin.

 

Clinical features

sharp knife like pain on respiration pneumococci, (Streptococcus pneumoniae)

young adults mostly                                       often rust coloured or purulent sputum

rapid shallow respirations                            the affected side moves less

dullness to percussion

 

Treatment

Antibiotics

Analgesia - do not suppress respiration or depress cough reflex, eg pethidine 100 mg

Large amounts of inflammatory exudate may completely fill one lobe of the lung

This process is described as consolidation

The pleural surface of the lobe is also inflamed and becomes covered with a shaggy thick layer of sticky fibrin, ie. pleurisy

Death may occur but most recover - the lung tissue recovers with little or no residual damage

 

Complications of pneumonia

Lung abscess

Severe localised suppuration associated with cavity formation

Often secondary to aspiration                     Secondary to obstruction

After septic pneumonia                               

Copious sputum often foul smelling due to anaerobic activity

Swinging fever                                               Ensure complete treatment in pneumonia

 

Empyema

Pus in the pleural cavity                                Often a complication of a ruptured abscess

Often anaerobic organisms             Patients are very ill with a high fever

 

Others

Cardiac failure           Endocarditis              Meningitis

Primary Atypical Pneumonia

Slow onset with a bronchopneumonia - like pathology.

Often caused by mycoplasma, Mycoplasma pneumoniae, (a type of organism like very small bacteria).

 

 

Tuberculosis

Approx. 10% of the worlds population die from TB

"captain of the men of death"

TB is reappearing in the west, factors,

 

Aetiology

Mycobacterium tuberculosis

 

Transmission

Transmitted in milk

Inhalation of bacteria in to lungs from an infected person

 

Diagnosis

AFBs              CXR                Positive tuberculin test reaction                  Unexplained cough

 

Clinical features

Influenza type symptoms or insidious onset

Fatigue, malaise, weight loss, low grade fever, anorexia etc.

Cough, mucoid or muco-purulent sputum

Haemoptysis, chest pain

Systemic involvement

 

Vaccination

BCG is a harmless form of tuberculosis grown on potatoes.

It leaves a small tubercle in the skin where it is injected, there will also be a tubercle in the armpit, and some degree of immunity to subsequent infection. 

 

Primary Infection

May be asymptomatic

Bacteria enter the lungs and divide, (droplet infection)

A small knot called a tubercle, composed of phagocytes

Some bacteria are usually carried to local lymph nodes

Usually cellular immunity develops and the infection subsides

If immunity does not develop, eg. due to immune overload the tubercle bacilli divide and  destroy some local cells.

Bacterial division and tissue destruction leads to the release of some bacteria into a bronchus.

This may cause a rapidly spreading bronchopneumonia, and also allow spread to any other part of the body.

Small tubercles may form anywhere and may be seen in the back of the eye. These look like millet seeds giving rise to the term miliary tuberculosis.

Tuberculosis bronchopneumonia and miliary tuberculosis are both rapidly fatal without treatment.

Even with treatment there may be residual damage to eyes, brain, bone and other organs.

 

Re-infection

A second infection will be different due to the pre-existing cellular immunity

In most cases the immune cells rapidly destroy the mycobacterium

However if the immunity is less efficient inflammatory and fibrous cells move to the bacteria, however these cells die without killing the bacteria and subsequently form a caseation, (cheesy like material)

Fibrous cells form a fibro-caseous lesion

This gives a situation of chronic inflammation, the damage done by the bacterial balanced by the action of inflammatory and fibrous cells

Inflammation and repair carry on

Local necrosis may occur resulting in cavitation

Mycobacteria may spread, eg. to vertebrae or kidney forming a cold abscess, (so called because the fibrous tissue on the outside shows no active inflammation).

 

Management

The aim of treatment is to improve the overall health of the patient to tilt the balance in his or her favour.

Isolate active pulmonary cases

Bed rest does not help

In combination with drugs, compliance is vital!!

Rifampicin, isoniazide, ethambutol, pyrazinamide, streptomycin

Resistance may become a problem

Contact tracing

Mantoux test indicated an individuals level of immunity.

 

Prevention

Promote vaccination

Promote good housing, prevent dampness and overcrowding

Prevent poverty                                                         Screen population movements

Teach disease awareness                                      Promote general physical and mental health

Avoid exposure to bacilli                                          Maintain degree of immunity

More common over age of 30

More common in presence of other diseases, eg. diabetes, silicosis

More common after recent GI surgery                                Alcoholism

 

 

 

Respiratory infections in children

 

 

Pharyngitis

 

Influenza

 

Otitis media

 

Croup

 

Acute epiglottitis

 

Bronchitis

 

Bronchiolitis – respiratory syncytial virus

 

Viral pneumonia

 

Pleurisy

 

Atypical pneumonia

 

Bacterial pneumonia

 

Tuberculosis

 

 

Other respiratory problems

 

Foreign bodies

 

Aspiration pneumonia

 

Heat and / or smoke inhalation