Entire textbooks have been written describing the topic of this short discussion. Obviously, the
entire area can hardly be covered in such a short time. What we would like to do, however, is
to touch upon a few important issues and to place the entire area into a more easily understood

Strategic Reserve: Normal, healthy people have built in levels of strategic physiologic reserve
as it relates to the functioning of the various organ systems. This fact is taken advantage of in
organ transplantation in that a close relative of a kidney patient may be an organ donor, giving
up a kidney and yet function essentially normally for the rest of his or her life. The amount of
reserve varies, but in general, nature has built a surplus into each system. As a rule, nature
generally does not do things wastefully and this strategic reserve handles the "overload" or
increase in need as the individual is challenged by various stresses. These stresses may take
many forms, such as physical privation during periods of starvation, injury following a motor
vehicle accident, or the flight or fright response when faced with anxiety provoking situations
such as dental treatment. In the last example, both pulse and blood pressure are raised, the
pupils dilated, the skin cool and clammy and the patient is ready to bolt at the slightest
provocation. Nature has built into the autonomic nervous system and the cardiovascular
system, the ability to "rise to the occasion" of impending threat with a temporary tapping of that
latent reserve in order to meet this threat.

Systemic Illness and Loss of Strategic Reserve: When viewed in this context, each system has
such a reserve, but this reserve is finite. The system can only tap its reserves so much in the
face of threat and when this reserve is exhausted, failure of the system in imminent. In the
medically compromised patient, this reserve is diminished as a function of chronic disease such
that the patient’s ability to "rise to the occasion" is diminished. The patient is less capable of
dealing with stress and prone to medical crisis. In the office setting this is not a practice builder.

For clarity, we have elected to discuss loss of strategic reserve, or illness, on a scale of 1 to 4.
For example, angina may be classified as follows:

       Class 1:   angina on extreme exertion (climbing 10 flights of stairs)
       Class 2:   angina on moderate exertion (climbing 2 flight of stairs)
       Class 3:   angina with normal activity (walking down the street)
       Class 4:   angina at rest (sitting watching TV)

As this example illustrated, the patient's strategic reserve diminishes as disease progresses
and the stress needed to induce angina decreases. This simple classification system can be
used for a number of other diseases as well. We have selected the following as some of the
more common.

Table I:              Disease Classification by Symptoms or Description
Disease             Class 1              Class 2              Class 3              Class 4

Myocardial          angina with          angina with          angina with          angina at
Ischemic            extreme              moderate             minimal              rest
Disease             exertion             exertion             exertion
                      or                    or                   or                   or
                    MI > 2 yrs           MI < 2 yrs           MI < 1 yr            MI<6mths

Congestive          SOB with             SOB with             SOB with             SOB at rest
Heart               extreme              moderate             minimal
Failure             exertion             exertion             exertion

Hyper-              diastolic            diastolic            diastolic            diastolic
tension             >90                  >95                  >100                 >110
                    <95                  <100                 <110
                       or                   or                   or                    or
                    no symptoms          minimal              moderate             severe
                                         symptoms             symptoms             symptoms
                                         (headache)           (CHF)                (stroke)

Asthma              cannot find          uses puffer          uses puffer          uses puffer
                    puffer               monthly              weekly               daily

COPD                SOB with             SOB                  SOB                  SOB
                    extreme              moderate             minimal              at rest
                    exertion             exertion             exertion

Diabetes            diet                 oral hypo-           controlled           brittle
                    controlled           glycemics            with insulin         diabetic
                       or                   or                   or                    or
                    no symptoms          minimal              moderate             severe
                                         symptoms             symptoms             symptoms
                                         (neuropathy)         (blurry vision)      (amputations
                                                                                   or MI or blind)

Bleeding            on ASA               on Coumadin          on Coumadin          hemophiliac
                                         with good control    with poor control    poorly
                       or                   or                   or                   or
                    no symptoms          minor bruising       moderate             severe
                                                              bruising or          bleeding or
                                                              bleeding             haemarthrosis

A very useful way to assess a patient's disease state is to determine what medication they are
taking. With most diseases, physicians use a staged or stair-stepped approach to
pharmacological management. As the disease state worsens, The strength and number of
drugs used tends to increase. Careful analysis of the patient's list of drugs usually indicates
their medical diagnosis and further analysis will indicate how advanced this disease is. This is
indicated for the above diseases with the following table:
Table II:         Disease Classification by Pharmacology

1. Myocardial Ischemic Disease

Class 1           vasodilator
Class 2           vasodilator    +     vasodilator
                  PRN                  prophylactically
Class 3           vasodilator    +     vasodilator +       B blocker
                  PRN                  prophylac-
Class 4           vasodilator    +     vasodilator +       B blocker       +     calcium
                  PRN                  prophylac-                                channel
                                       tically                                   blocker

examples          nitro-               Isordil             Timolol               Nifedipine
                  glycerine            nitropaste          Labetolol             Diltiazem
                                                           Propranolol           Verpamil

2. Congestive Heart Failure (CHF)

Class 1           diuretic
Class 2           diuretic       +     second
Class 3           diuretic       +     second              +     inotrope
Class 4           diuretic       +     second              +     inotrope        +      home
                                       diuretic                                         oxygen

examples          Diazide              Lasix                     Digoxin                oxygen

3. Hypertension

Class 1           B blocker
Class 2           B blocker      +     diuretic
Class 3           B blocker      +     diuretic      +     ACE inhibitor
Class 4           diuretic       +     diuretic      +     ACE inhibitor         +Ca channel

examples    Timolol              Diazide             Captopril             Nifedipine
            Labetolol            Lasix               Enalapril             Diltiazem
            Propranolol                                                    Verapamil
4. Asthma

Class 1   bronco- dilator
Class 2   bronco- dilator + proph steroids
Class 3   bronco- dilator + proph steroids + proph bronco-dilator
Class 4   bronco- dilator + proph steroids + proph bronco-dilator + histamine vesicle

examples      Ventolin      Beclovent        Theophylline            Chromolyn

5. Chronic Obstructive Pulmonary Disease (COPD)

Class 1       bronco-
              dilator PRN

Class 2       bronco-     + proph steroids
              dilator PRN

Class 3       bronco-     + proph steroids + proph bronco-
              dilator PRN                    dilator

Class 4       bronco-     + proph steroids + proph bronco-           +      antibiotics
              dilator PRN                    dilator                        & home oxygen

examples      Ventolin      Beclovent          Theophylline                 Ceclor
                                               (Theodur)                    Oxygen

6. Diabetes

Class 1             diet

Class 2             diet          +      oral hypo-

Class 3             diet          +      oral hypo-   +       insulin
                                         glycemic             (minimal
                                                              dose change)

Class 4             diet          +      oral hypo-   +       insulin       +    insulin
                                         glycemic             (minimal           (multiple
                                                              hospital)          hospital)

examples            CHO                  Glyburide            Humulin            Humulin
                    restriction          Diabinase            NPH / Lente        NPH / Lente
7. Bleeding problems (Bleeding diatheses / coagulopathies)

Class 1              ASA

Class 2                            Coumadin
                                   INR < 1.5

Class 3                                                 Coumadin
                                                        INR > 1.5

Class 4                                                                     Haemophilia

examples     post MI               for atrial           previous            (multiple
             Proph                 fibrillation         DVT or              hospitalizations)
                                                        prosthetic valve

Procedural Stress:

From a systemic point of view, each procedure we do carries with it a certain level of stress to
the patient. Simple procedures such as denture adjustments, examinations or radiographs
carry minimal stress. More complex procedures such as scaling or root planing, simple
restorations or impressions carry increased levels of demand on the system. Still more
complex procedures such as lengthy crown and bridge appointments or extractions are
increasingly stressful. Finally, complicated surgery such as difficult impactions or orthognathic
surgery carry even greater levels of threat to the patient. The threat any given procedure
presents to a patient may be magnified as a function of patient anxiety and this factor must also
be taken into the equation. In general, a simple categorization of stress levels may be applied to
given procedures:

      Level 1:       denture adjustments, examinations or radiographs

      Level 2:       scaling or root planing, simple restorations or impressions

      Level 3:       lengthy crown and bridge appointments or extractions

      Level 4:       difficult impaction or orthognathic surgery

Our job as clinicians is to assess this reserve, to assess the threat to the system that our
procedure represents and to make sure that we stay within the limits of the systems's ability to
handle the threat. When procedural "threat", "stress" or "complexity" exceeds the patient's
ability to handle the situation, we are faced with the potential for medical crisis. Careful
assessment of risk allows us to avoid precipitating medical emergencies.
For each system…fill in the blanks as you progress through the course:











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