ASTHMA

DEFINITION

It is defined as a chronic inflammatory disorder of the airways characterized by reversible airflow obstruction causing cough, wheeze, chest tightness and shortness of breath

TYPES

EARLY ONSET / ATOPIC / EXTRINSIC

Begins in childhood, generally occurs in atopic individuals who readily form IgE antibodies to commonly encountered allergens

LATE ONSET / NON ATOPIC / INTRINSIC ASTHMA

Develops in adults who are non atopic and is related to mast cell instability and hyperesponsive airways

CLINICAL FEATURES

Episodic shortness of breath( dyspnea )

Wheezing

Bouts of coughing

Chest tightness

PRECIPITATING FACTORS

Allergens

Exercise

Cold air

Emotional extremes

Viral infections

INVESTIGATIONS

Spiro meter

Chest X rays

Arterial blood gases

MANAGEMENT OF CHRONIC PERSISTENT ASTHMA

STATUS ASTHAMATICUS

It is now known as Severe acute asthma

It is the most severe clinical form of asthma

Patient experiences wheeze, dyspnea and hypoxia that are refractory to 2-3 doses of β adrenergic agents

If not treated the patient may die of respiratory collapse

DENTAL CONSIDERATIONS

Fluoride supplements should be instructed for all asthmatics ,particularly those taking B2 agonists

The patient should be instructed to rinse the mouth after the use of inhalers

Antifungal medications should be administered as needed especially to those on corticosteroids

Steroid prophylaxis is to be used for those on long term steroids

Use of stress reducing techniques

Avoid dental materials that may precipitate an attack for e.g. acrylics, fissure sealants

Schedule appointments for late mornings to minimize te risk of an attack

Have oxygen and bronchodilators ready in case of an attack

LA – preservatives such as methyl bisulfite may precipitate an attack

Upto 10% of adult asthmatics are allergic to aspirin and other NSAIDS

Drug interactions with theophylline are common

ciprofloxacin and macrolides increase the level and phenobarbitals reduce the level

CHRONIC OBSTRUCTIVE AIRWAYS DISEASE

CHRONIC BRONCHITIS:

is defined as the excessive production of mucus and persistent cough with sputum production for more than 3 months in a year over 3 consecutive years

leads to production of excessive, viscous mucus, which is ineffectively cleared from the airway, stagnates & becomes infected with S. pneumoniae and H. influenzae

Emphysema is dilatation of air spaces distal to the terminal bronchioles with destruction of alveoli and a reduction in the alveolar surface area available for respiratory exchange.

Early morning mucoid cough

Mucopurulent sputum

Dyspnoea

Dyspnoea on effort

Chronic hypoxaemia (‘BLUE BLOATED’ appearance)

DIAGNOSIS

History

Clinically supported by chest radiography

Respiratory function tests

Occasionally arterial blood gas estimations

General management

Stop smoking

In presence of infection:

-Co-trimoxazole or amoxycillin. lpratropium bromide, or other bronchodilators may be beneficial.

Respiratory failure and cor pulmonale may also need to be treated

Dental aspects

Dental treatment : LA

Patients are best treated in the upright position as they may become increasingly breathless if laid flat

Do not use rubber dam

GA only if absolutely necessary, and only in hospital after full preoperative assessment

Diazepam and midazolam are also mild respiratory depressants and should not be used for intravenous sedation

Intravenous barbiturates are totally contraindicated.

Patients taking ipratropium may have a dry mouth

PRE-ANAESTHETIC ASSESSMENT

Spirometry and carbon monoxide perfusion are essential to assess respiratory function

cessation of smoking for at least 1 week preoperatively

Respiratory infections must also be eradicated

Sputum : culture and sensitivity, but antimicrobials such as co-trimoxazole or amoxycillin should be started without awaiting results

Bronchodilator drugs are useful for bronchospasm

Thorough and frequent chest physiotherapy is important preoperatively and, if there is congestive cardiac failure, diuretics are indicated

It is safest to avoid premedication

Morphine is certainly contraindicated since it can impair the cough reflex or precipitate bronchospasm

Pethidine can be used if the patient is in pain

Atropine and related antimuscarinics are also best avoided since they dry up the airways and increase the risk of postoperative pulmonary complications.

Postoperative care

Close continuous assessment

In hypoventilation or excess secretions : tracheostomy

Bedridden patients with chronic obstructive airways disease may have added complications if given a general anaesthetic

Impaired cardiovascular responses may lead to profound hypotension if agents such as barbiturates are used.

Cor pulmonale may be aggravated by the cardio-depressant activity of drugs used in anaesthesia or by the water retention that follows surgery or anaesthesia.

Secondary polycythaemia may predispose to thromboses postoperatively

TUBERCULOSIS

Caused by Mycobacterium Tuberculosis

Primary infections involve spread by inhalation of mycobacteria laden respiratory micro droplets

Different states include:

asymptomatic primary tuberculosis

symptomatic primary tuberculosis

progressive primary tuberculosis

reactivation tuberculosis

PREDISPOSING FACTORS

Poor Nutrition

General debilitating disease including human immunodeficiency virus

Iatrogenic immunosuppression overcrowded living conditions

Certain respiratory diseases such as silicosis

As a result of improved public health measures and the availability of anti tuberculosis drugs, the incidence of tuberculosis had decreased, unfortunately increased incidence of immunosuppressive diseases like AIDS, tuberculosis remains a major concern and challenge to health services

CLINICAL FEATURES

Chest pain

Blood streaked sputum

Prolonged productive cough for more than 3 months

Loss of weight

Night sweats

Fever

PERSONS AT HIGH RISK FOR CONTRACTING TB

ORAL MANIFESTATIONS

Oral lesions are an infrequent occurrence in tuberculosis and are observed more often in patients with advanced disease.

Oral tuberculous lesions may be either primary or secondary.

Primary oral tuberculous lesions are relatively rare and generally occur in younger patients. The mechanism of primary inoculation is not definite, but it is believed that organism enter the mucosa through a small surface break.

The secondary lesions on the contrary are more common and are seen mostly in older persons through sputum.

The bony structures of the oral cavity are affected less frequently than the soft tissue.

Tongue is the commonest site for oral tuberculous lesion but lesions they may also occur in the gingiva, floor of mouth, palate, lips and Buccal mucosa

It may also present around the upper aero digestive tract as parotitis, intra–osseous lesion, trachitis and laryngitis.

.

In the primary type, the causative organisms are directly inoculated in the oral mucosa of a person who has not had tuberculosis earlier and who has not acquired immunity to the disease. In the secondary type tuberculosis of the oral cavity it is usually consistent with pulmonary disease and is primarily a self – inoculation

Mucosal lesions may appear as ulcer, nodules, fissures, sometimes with mild to moderate induration. Human infections from bovine type occur with the ingestion of infected milk. The pathogenesis is similar to M. tuberculosis except that the primary inoculation is in the mouth tonsil or intestine.

ATYPICAL TUBERCULOSIS

Caused by

Mycobacterium avium intracellulare

M. scrofulaceum

M. xenopi

M. malmoense

. Differential diagnosis of oral tuberculosis includes a traumatic ulcer, apthous ulcer actinomycosis, syphilitic ulcer, Wegener’s granuloma, carcinoma, Sarcoidosis, deep mycotic infections.

TREATMENT

Rifampicin 450mg once a day

Isoniazid 300mg once a day

Ethambutol 600mg once a day

Pyridoxine supplement with isoniazid

This regime for 2 months

followed by Rifampicin and

isoniazid for 7 months

PREVENTION OF CROSS INFECTION

Reduction of splatter and aerosols by minimising coughing, avoiding ultrasonic instruments and by use of rubber dams

Improved ventilation, ultraviolet lights , new masks and personal respirators

Use of heat sterilization

GA contraindicated risk of contamination of instruments, impaired pulmonary function

ANTI TUBERCULAR THERAPY