Energy cost of Rx

Energy & Metabolic


When selecting treatment choices, there is a danger of doing so by lists:
   'This is the accepted intervention for that defined problem.'


Ask yourself this, did that sentence sound incorrect or too vague to comprehend? Yes? Then we have much to discuss.

Lists can become long. Consider this, as a mental exercise. You have a metabolic tally sheet and every procedure you propose to do gets tallied along with the total metabolic demand it requires ( calories required, total protein cost, cardiac load - all of it). You do this on a spreadsheet that not only does the tally for you but color codes the list...

Say, on a big healthy person

    Proposal for Thor Bigbody:
    1. Haircut
    2. Manicure.
    3. Dental cleaning.


Another proposal, for a very thin kid who really needs a feeding tube but who has a scoliosis going out of control, and many contractures and a dislocating (nearly) hip.

    Proposal for Agnatha Hungerford:
    1. Remove skin tag.
    2. Botox to thumb adductor
    3. Lengthening of right and left muscle contractures with
    4. Reduction of right hip subluxation
    5. Pelvic osteotomy on right to deepen hip
    6. Opposite side (good side) femoral osteotomy
       ( to equalize limb geometry )
    7. Posterior spinal fusion.


The list turns red as the scope of metabolic demand for healing the surgery pushes the limit of what the individual has in capability. Crossing this boundary may well manifest as slowed healing. It may also manifest as inability to do other things - things not obviously part of the surgery - such as grow hair, or or fend off bacteria. Perhaps fail to make bone where bone is needed.


Dr. Moore of the Peter Bent Brigham Hospital in Boston did some very wonderful work following the Cocoanut Grove fire disaster. Aside from handling a glut of burn victims, he studied how they handled fluids and healing. That work on burns really ought to be lifted directly by all surgical fields. The percent body burn and limitation of resources thinking is clear enough.


So, consider a long posterior spinal fusion as metabolic equivalent of a 25% body burn. (that's my own guess). The fluid shifts and bodily reserves required are better appreciated when put into familiar terminology. We need some scale as this.


Those old ladies who languish after hip fracture are glowing examples. They did not FALL and break their hip. They were in metabolic decline losing bone steadily until the hip gave way. Then, unsupported, fell. It does not follow that they will heal it. At the Massachusetts General Hospital, many years ago, we tallied the survival of such patients. 50% were dead within the year. This was not death by fracture. It was fracture by graduated death.


The use of dry ice for severe infection in overwhelmed patients with poor reserves made a huge (nearly miraculous) difference in survival. Parts medically 'amputated' (frozen) with dry ice allowed metabolic intervention and later surgical resolution.


So. What do we learn? We need to have some degree of health for large surgeries. There has to be some reserve to draw upon. A skinny skin & bones kid is a danger.


Chronic Shock Syndrome

The cross section of a vein is larger than the artery it is paired with. Therefore the flow volume, in veins is slower and that of arteries faster and under more pressure. The total venous tree holds six times more blood than the arterial tree.

In a pinch, acute blood loss, the body can squeeze down the veins and narrow them as blood is lost. This is how we don't just croak with small losses of blood. The venous system is a gas tank by being over sized and able to shrink.

Bleeding is obvious enough. But, when the individual cannot self control fluid intake (fed by others) or perhaps correctly internally gage needs, the fluid capacity of the veins may slowly make up for differences. This is the danger. If the changes are very slow and over a long period, they are not appreciated. The individual may well have a venous tree no bigger than the arterial tree. That is, the reserve is gone. No extra. Small acute losses will result in catastrophic collapse as if there were massive bleeding.
More on this?


In addition, blood tests in such a person with what we call chronic shock (venous volume depletion without symptoms), - those tests are NORMAL!

The test tell us concentration. They don't tell us volume. The only clue might be concentrated urine, but even  that becomes adapted to long standing depletion. Might not show there either.


A small loss of blood replaced by substitutes (certain IV fluids) in anticipation of blood loss might lose most of the circulating platelets and clotting factors. Small infusions of fluids may cause potassium, sodium and calcium levels to precipitously drop. Rapid pulse is followed by dropping blood constituents and the hematocrit (red cell concentration) seems to plummet. There is no visible blood loss to match what seems to be going on. By responding with a push of of fluids the concentration of protein in the IV expanded volume is insufficient to hold it within the vascular tree. Fluids do not stay inside the vessels by magic. Fluids are held by the sponge-like attraction of blood proteins. Chronic shock patients do not have the protein QUANTITY to handle a "REHYDRATION" with IV fluids. Such a fluid push will dump into the bowels, the lungs and the brain. Not good.


Bottom Line:

Ready for the bottom line? This is the good part. Do you know what heads off all this mess? Really. The answer is hidden here =>NUTRITION<= highlight it.


That is why we harangue about
 =>feeding tubes & preop preparation etc.<=.


Muscular Dystrophy Issues

It is heard over and over about which procedures will - done as prophylaxis - will extend walking time. No actual paired series exist. But here is what isn't discussed sufficiently. This is a global disease. Two simultaneous things are at play.

As skeletal muscle loss causes impairments, the efficiency of gait falls off precipitously. That is, the same walk across the room costs much more energy. Our walking mechanism is an insanely fine tuned mechanism which employs the most subtle control to assure energy conservation. Small control loses by either strength or by timing anomaly cost energy big time.

Meanwhile, the mechanisms that deliver fuel - energy - are also being impeded. The heart muscle may well be massively involved. Only the serious loss of function masks the cardiac impairment. No matter how you tweak the limbs, they still need considerable fuel when performing. Walking will fail when the ability to deliver that fuel is below the demand. Period.

The newer steroids may well be having their main effects on walking via the cardiac effects. We cannot allow ourselves to 'put off' required large surgeries (spinal) when the ability to respond is impaired.

So, consider two circumstances. Those in which the motor problems require significant intervention and the central ability to deliver energy (feeding and circulation) are robust. And those wherein the central energy delivery mechanism is impaired and perhaps deteriorating.