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Medical Emergencies in the Dental Practice

In Dental Emergencies on July 25, 2013 by Dr Gregory Lloyds Tagged:

 emergencies dental practiceThe aim of  Lloyds Dental Practice Emergencies Research (LDPER) website is to assist the dentist in the prevention and treatment of emergencies that may occur in the surgery.

The emergencies may be due to medical disease in the patient or to problems with drugs and drug therapy.  A careful medical and dental history may prevent an emergency as may alert the dentist to a particular problem and allow the choice of the most appropriate treatment for the patient.  Its value cannot be overemphasised.

Further information may be obtained by consulting the patient’s practitioner. This is advisable whenever the patient appears to have medical problem.

If complications are anticipated, it may be advisable to admit the patient to hospital for dental treatment (for more info go to www.dentistcronulla.net.au). The Oxygen Therapy Sections of this website will deal with the various emergencies that may occur in the dental surgery. Oxygen therapy and basic life support techniques, together with other aspects of treatment, are described.

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Diseases That May Affect the Management of the Dental Patient

In Dental Patient Diseases on July 23, 2013 by Dr Gregory Lloyds

dental infection managementAlthough the majority of patients attending dentist Sutherland,for dental treatment are healthy, everyone is subject to minor acute infections such as the common cold and influenza. While such infections normally settle within a few days, others, particularly in the more elderly patient, may get worse or be followed by complications. It is therefore unwise to subject any patient with an acute infection to the extra stress of an elective operation; these should normally be deferred until the patient has recovered. Attendance at the dental surgery should also be discouraged, in order to prevent the spread of infection to other dental patients and staff.

A number of dental patients will have sub-acute or chronic disease affecting the various organs and systems of the body. In some, the disease will be symptomless and patient unaware of it; in others, as a result of treatment, the patient may feel completely fit and have little or no limitation of activity: he or she is able to work, take an active part in sport and lead a normal life. While patients in the second group are likely to tolerate operations well, it is particularly important to take a careful history as the drugs with which they may be being treated may seriously affect the course of their dental treatment, and place them particularly ‘at risk’ while undergoing operative procedures.

There remains a third group of patients who, in the presence of severe disease and despite treatment, have progressive restriction placed on their activity. These ‘decompensated’ patients, who are often unable to work, are operative risks, and while every attempt should be made to treat and control their disease before surgery, it may be necessary after consultation with the patient’s physician to decide that the risk of an elective operation is unwarranted.

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Australian Dental Hospitals

In Dental Hospitals on December 2, 2013 by Dr Gregory Lloyds

If superficiallyAustralian dental hospitals could be described as a cottage industry of over 1100 separate facilities with nearly 100 000 beds dotted over the continent, closer scrutiny might suggest otherwise. Their apparently random distribution, sometimes long distances from each other, at other times a street apart, the variations in ownership and control, the great differences in size and in function, might all suggest an inchoate industry totally lacking the benefits to be derived from concentrated large-scale operation, centralized control, national planning, and orderly distribution. Yet such a judgement, while containing significant elements of truth, would be at the same time a distorted representation of the industry. For all that its origins lie in a ‘nationalized’ system of hospital care at the time of white settlement, admittedly for practical rather than ideological reasons, today’s Australian dental hospital industry is pluralist in nature and represents the interests of a disparate series of groups. As might be surmised, one of the features of such a system is a certain degree of confusion when the question of categorization arises with the outcome depending largely on who is making the judgement and the criteria being used. The broad picture is set out below, notwithstanding definitional niceties.

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Drugs Which May Precipitate Emergencies in Dental Practice

In Drugs in Dental Practice on September 26, 2013 by Dr Gregory Lloyds

drugs in dental practiceThe most frequently used drugs in dentistry are local anaesthetics, either plain or in combination with a vasoconstrictor. Their side effects are likely to be the cause of many of the emergencies encountered by dentists. Certain precautions should always be taken when they are used. Below are listed the toxic manifestations of each agent, but it should be remembered that some of the effects of the base will be masked by the vasoconstrictor.

In practice it would seem that the commonest side effects seen are those due to adrenaline or nor-adrenaline. If the warning signs associate: with these toxic effects are not appreciated and administration ceased, there I is a high risk that the patient will collapse.

Adverse and toxic effects are determined by:

  1. Concentration and volume of solution.
  2. Rate of injection.
  3. Toxicity of agent.
  4. Presence or absence of vasoconstrictors.
  5. Physical status of the patient and his or her current drug therapy.

The major cause of systemic reactions is a high blood level of local anaesthetic base or vasoconstrictor. The aim must be to use the smallest volume of lowest concentration to achieve satisfactory anaesthesia.

In order to avoid these effects, the following precautions should be taken:

Patient History

An adequate patient history should be taken. Certain diseases or the concurrent use of some drugs accentuate the undesirable side effects of adrenaline or nor-adrenaline.

Their use is absolutely contra-indicated in the following conditions:

1. Sensitivity to catecholamines.
2. Thyrotoxicosis  – Their use is also contra-indicated where the patient is receiving the following drugs:
2.1. Sympathomimetic agents
2.2. Tricyclic antidepressant drugs, MAOI inhibitors.
2.3. Certain general anaesthetic agents (halothane, chloroform, trichlorethylene).

In these conditions felypressin (octapressin) is a safe alternative vasoconstrictor to adrenaline and nor-adrenaline, and may be used in circumstances where adverse reaction to these drugs is anticipated. Felypressin is the vasoconstrictor of choice should one be required in patients with cardiovascular disease and hypertension.

Aspiration Prior to Injection

Aspiration should always be performed prior to injection of any local anaesthetic solution. The toxic effect of both local anaesthetic and vasoconstrictor are increased where they are injected intravenously, so aspiration should always be performed prior to injection.

Inadvertent intravenous injection may occur not only with mandibular and maxillary block injections, but also in infiltration of both facial and palatal sites. An adequate aspirating syringe with a needle no finer than 26 gauge should be used for all injections and at least 2 seconds should be allowed for the aspiration.

Rate of Injection

Injections should be undertaken slowly, ideally at the rate of 1 mL per 30 seconds, to minimise possible toxic effects. Patients in the Sutherland Shire should be monitored for toxic effects which may occur occasionally at relatively low doses in susceptible persons.

Dose

Local Anaesthetic  – The maximum dose of local anaesthetic base should be calculated from the weight of the patient particularly in infants and children. The maximum dose will depend on whether the local anaesthetic is plain or has vasoconstrictor added, as the latter will lessen the rate of absorption of the base.

Catecholamines - Clinically effective vasoconstriction for dental anaesthesia can be obtained with concentration in the range of 1:300 000 (3.3 ug/mL) adrenaline to 1:100 000 (10.0 ug/mL), and in order to minimise toxic effects the lowest effective concentration should be used. Where adrenaline is used a concentration of 1:80 000 (12.5 ug/mL) should not be exceeded and where nor-adrenaline is used a maximum of1:50 000 (20.0 ug/mL) is suggested.

Sedatives, Hypnotics and Analgesics

Sedative – A drug which allays apprehension, but does not produce analgesia.
Hypnotic – A drug which induces sleep, but does not produce analgesia.
Analgesic – A drug which reduces the patient’s perception of pain.
The response to hypnotic drugs is dose dependent and many hypnotics given in small doses will act as sedatives. Long-continued use of depressant drugs produces tolerance to the psychic effects of sedative drugs. Caution is always needed because metabolic disturbances or drug interaction may lead to depression of respiration which may, in turn, permit respiratory obstruction and respiratory failure as well as circulatory depression. As well as the specific sedatives and hypnotics, all tranquillisers, some antihypertensive drugs, antidepressant and antihistamines may have sedation as a side effect.

Pain Relief

Unless pain is first controlled by analgesics or narcotics, the administration of sedatives will cause restlessness.

Pain may be controlled by:

  1. Analgesic drugs.
  2. Narcotics, which may induce sleep as well as relieve pain.
  3. General anaesthesia, which implies freedom from pain, produced by rendering the patient unconscious. Analgesics may be administered orally, by injection or by inhalation. They may be divided into two groups:
    1. Mild analgesics which act peripherally.
    2. Potent analgesics which exert a depressing action on the central nervous system.

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Allergies in Dentistry

In Allergies on September 19, 2013 by Dr Gregory Lloyds

Manifestations : Allergic reaction or ‘collapse’ following administration of drugs, especially penicillin.
Drug Therapy : Antihistamines, corticosteroids.
Dangers : Anaphylaxis.

allergies in dentistrySometimes the body responds to the entry of a foreign substance by the formation of a specific antibody. This antibody circulates in the blood and lodges in various organs. When the response is controlled and to the patient’s benefit, it is called immunization and the antibody neutralizes the foreign substance. A small number of people form an unusual antibody that produces undesirable effects while the foreign substance is in the process of naturalization. These people are allergic or hypersensitive and the undesirable effects are called allergy.
Anaphylaxis is the acute allergic reaction which usually follows the administration of a drug by injection; in its most severe form it is life threatening.
The signs of an acute allergic reaction are:

  1. Itching and prickling sensations and the appearance of hives, weals and blotches.
  2. An asthma-like attack with wheezing and cyanosis.
  3. A serious fall of blood pressure, called anaphylactic shock.
  4. Unconsciousness and cardiorespiratory arrest.
  5. Swelling of the mouth, tongue and throat.

Anaphylaxis may appear in seconds or minutes depending on the rate of absorption of the drug from the site of injection. Serum sickness is the delayed allergic reaction. It occurs days or weeks after the injection and it consists of fever, rashes, painful joints and swelling of the lymph glands. Serum sickness is not a life-threatening reaction.

Unfortunately the term allergy is often used loosely to cover any undesirable reaction to a drug. However, in practice, toxic effects, side effects and idiosyncrasy are more frequent. The pharmacological actions of a drug other than those for which it is administered are called side effects. For example, pethidine is used to relieve pain but it also depresses respiration and causes nausea; the latter are side effects. Some patients get exaggerated pharmacological reactions and they are said to have idiosyncrasy, e.g. prolonged, severe vomiting after pethidine. Toxic effects occur when a drug enters the bloodstream in a high concentration as the result of overdosage or inadvertent intravenous injection, e.g. unconsciousness and respiratory arrest after an injection of pethidine.

Patients sometimes say that they ‘collapsed’ during an operation or an anesthetic. It is essential to find out the exact cause by contacting the surgeon or the anesthetist personally. A history of eczema, hay fever and asthma is a warning that the patient has an allergic diathesis. Specific questions should be asked about reactions to drugs, particularly antibiotics, barbiturates and narcotics. Patients must not be exposed to a drug if a past allergic reaction is suspected – alternative medication is always available. Test doses are unreliable and dangerous and it is impossible to suppress allergic responses with certainty by pre-treatment with corticosteroids or antihistamines.

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Managing the Patient with Musculo-Skeletal Disease

In Musculo-Skeletal on September 11, 2013 by Dr Gregory Lloyds

Manifestations  : Paralysis or weakness of muscles. Deformity and rigidity of joints.
Drug Therapy : Corticosteroids for rheumatoid arthritis.
Dangers  : If affecting the chest, throat or mouth.

dental patients respiratoryDiseases of the musculo-skeletal system are unlikely to influence the course of surgery unless they affect the chest, throat and mouth. In these vital areas, paralysis, deformity or rigidity may cause serious respiratory difficulty. Fortunately this is rare, but it may be encountered in myasthenia gravis, the muscular dystrophies and advanced ankylosing spondylitis.

In some of the rarer myopathies – usually, but not invariably, those associated with a family history – malignant hyperpyrexia may follow general anaesthesia.

Corticosteroids are used in the treatment of rheumatoid arthritis.

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Liver Disease and Dental Management

In Dental Patient Diseases, Liver Disease on September 6, 2013 by Dr Gregory Lloyds Tagged:

Manifestations  : Cirrhosis, disorders of hydration and coagulation.
Drug Therapy  : Diuretics, corticosteroids.
Dangers  : Hepatitis B. Reduced ability to detoxify sedatives, narcotics, local anaesthetics.

patients with liver diseaseChronic disease of the liver is called cirrhosis. The commonest cause is the prolonged, excessive intake of alcohol but it occasionally follows longstanding hepatitis. In decompensated cirrhosis, fluid accumulates in the abdomen and in dependent parts of the body. The patient complains of weakness, abdominal discomfort and puffy ankles. In acute liver disease the skin and eyes are jaundiced.

Intensive treatment of cirrhosis with diuretics can lead to dehydration and a tendency to syncope. A severely damaged liver fails to synthesise coagulation factors normally and this leads to a bleeding tendency; also, it fails to detoxify many drugs, including sedatives, narcotics and some local anaesthetics, but this is not usually a problem in dental practice.

Some patients with liver disease carry the virus of hepatitis B and some may be having treatment with corticosteroids.

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Dental Considerations in Patients with Kidney Disease

In Dental Emergencies, Kidney Disease on August 29, 2013 by Dr Gregory Lloyds

Manifestations   : Renal failure manifested by anaemia, bleeding tendency, fluid and electrolyte disturbance.
Drug Therapy  : Corticosteroids.
Dangers  : Drug intolerance, especially to antibiotics; hepatitis B.

dental patient kidney diseaseAcute renal disease, such as pyelitis, should not cause problems for the dentist as treatment of the acute condition will take precedence over dental treatment.

Chronic disease of the kidney, nephritis or pyelonephritis may develop as a result of such acute episodes, and in the early stages, although the patient may still be able to lead a relatively normal life, anaemia, a tendency to bleed and changes in water and electrolyte balance will be present. In the later stages of renal disease, as these changes become more marked, dehydration results in an increased risk of hypotension and syncope, while if overhydration occurs, pulmonary congestion may develop. At this stage in their disease, most patients will be awaiting transplantation and/or receiving dialysis with an artificial kidney; consequently they may be receiving large doses of corticosteroids together with other immunosuppressants, which predispose to infection.

Most drugs administered at the time of surgery are detoxified in the liver and do not have an unduly prolonged effect. In patients with renal failure some antibiotics are nephrotoxic – e.g. tetracycline, which is contra-indicated in renal failure – and great care should be taken both in choosing antibiotics and in prescribing an appropriately reduced dose. Dental treatment and the prescription of drugs by the dentist should only be undertaken after consultation with the patient’s physician, and except in the early stages of disease, should, wherever possible, be undertaken in hospital.

Patients who are undergoing renal dialysis or who have experienced transplantation may have hepatitis virus present in both blood and saliva, and the dental surgeon is accordingly advised to wear gloves and mask when giving treatment.

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The Dental Management of Patients with Endocrine Disease

In Dental Patient Diseases, Diabetes on August 23, 2013 by Dr Gregory Lloyds

Manifestations  : Hyper- or hypofunction.
Drug Therapy  : Diabetes: Oral hypoglycaemics, insulin. Corticosteroids.
Dangers  : Respiratory obstruction from thyroid goitre. Hypo- or hyperglycemia in diabetic patients. Insufficient corticosteroid ‘cover’.

diabetes in dental patients

Diabetic coma, a life-threatening dental emergency

The endocrine glands are responsible for the secretion of hormones. For instance, the thyroid gland secretes thyroxin, the pancreas secretes insulin and the adrenal gland secretes hydrocortisone. These substances circulate in the blood and control many of the bodily functions. Excessive hormonal secretion or hyperfunction may occur and can be treated in a variety of ways. Destructive disease leads to hormonal deficiency or hypofunction. The commercial availability of hormones permits the successful treatment of hypofunction. Consultation with the patient’s physician and control of endocrine disease are essential before elective surgery.

Disease of the thyroid gland in the neck is frequent. Enlargement of the gland or goitre does not adversely affect the course of surgery unless it is causing difficulty in breathing or swallowing or unless it is causing an uncontrolled hyperfunction called thyrotoxicosis or an uncontrolled hypofunction called myxoedema.

Diabetes is due to a relative or absolute deficiency of insulin. When mild, the disease is controlled well by careful dieting and weight reduction either alone or together with oral hypoglycaemic drugs. Severe disease necessitates the injection of insulin once or twice daily. Uncontrolled, severe diabetes leads to overbreathing, dehydration, shock and unconsciousness. This is a diabetic coma, a life-threatening emergency.

Hydrocortisone has been found to have a favourable influence on the course of many chronic diseases (e.g. asthma, arthritis, dermatitis and colitis) because hydrocortisone can suppress the immune response. There are many proprietary preparations of hydrocortisone and collectively they are 4 called corticosteroids. When so used the function of the adrenal gland is suppressed by a feedback mechanism during administration and for a variable period afterwards. During the period of suppression, the patient should receive a ‘steroid cover’ for any major stress or operation. This prevents the occurrence of adrenal failure, a condition leading to weakness, nausea and vomiting, progressive hypotension, drowsiness and, without treatment, death.

The insulin-dependent diabetic may become worse with the stress of major surgery, so continued control with injections of insulin is necessary. If fasting is required for the operation and the anaesthetic, insulin must be ‘covered with I.V. glucose to avoid dangerous hypoglycaemia. In these circumstances, the patient should be admitted to hospital. The oral antidiabetic drugs can cause hypoglycaemia if the patient fasts for longer than 4-6 hours.

Diabetics are usually able to recognise incipient hypoglycaemia by the onset of hunger, sweating, palpitations and tremor. The patient may appear drowsy and be sweating, and may lose concentration or become aggressive. The patient will look pale and the pulse rate will be high. The reaction can be relieved rapidly by taking 15-20 grams of sugar, i.e. a glass of fresh orange juice, or a cup of tea or coffee with 4 teaspoons of sugar (a teaspoon of sugar contains 5 grams). Persistent reduction of blood glucose leads to uncontrollable behaviour, unconsciousness and convulsions.  At this stage glucose must be given I.V. as soon as possible to avoid brain damage.

 

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